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September 7, 2016
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https://www.sciencedaily.com/releases/2016/09/160907160628.htm
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Calculating the role of lakes in global warming
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As global temperatures rise, how will lake ecosystems respond? As they warm, will lakes -- which make up only 3 percent of the landscape, but bury more carbon than the world's oceans combined -- release more of the greenhouse gases carbon dioxide and methane? And might that create a feedback loop that leads to further warming?
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To predict the effects of rising air temperatures on the carbon cycle of lakes, Rensselaer Polytechnic Institute researchers will link computer models of changing weather, water temperature, and emissions of carbon dioxide and methane for 2,000 lakes across the United States, including Lake George, through 2105. The project is supported with a $300,000 grant from the National Science Foundation, and led by Kevin Rose, an assistant professor in the Department of Biological Sciences at Rensselaer and the Frederic R. Kolleck '52 Career Development Chair in Freshwater Ecology."We know lakes are important in the global carbon cycle -- absorbing and emitting carbon -- and that's critical to regulating global air temperatures. But we don't know how the role of lakes will change as a result of rising air temperatures," said Rose. "Right now, we can model changes for an individual lake -- using characteristics like surface area, depth, water clarity, and temperature profile -- but to be useful as a planning and research tool, we need to work on a much larger scale."Carbon enters a lake as organic matter (such as falling leaves or soil suspended in runoff) and is cycled through the food chain, feeding plants and then animals. Some carbon settles to the lake bottom and is buried in sediment, but some is released back into the atmosphere as carbon dioxide and methane. As with all biological processes, lake emissions are temperature dependent, rising and falling along a temperature gradient. The challenge in predicting lake emissions for thousands of lakes across the country lies in the enormous variety of characteristics from lake to lake.To tackle that challenge, the project will forecast future weather conditions for 2,000 lakes over the next 90 years using high-resolution weather forecasting models and projections of climate change provided by the Intergovernmental Panel on Climate Change.In the second phase of the project, the team will draw upon the U.S. Environmental Protection Agency (EPA) National Lakes Assessment, a statistical survey that tracks chemical, biological, and physical characteristics of the target lakes. By feeding those characteristics and the forecasted weather data into an existing open source hydrodynamic model, the team will generate predicted changes in lake thermal characteristics such as the temperature profile (mapping temperature according to depth), depth of temperature stratification, and ice cover.The team is able to calibrate and validate the model by running the model back through time, as far back as 1979, and comparing their results with recorded weather and lake temperature data available from the North American Land Data Assimilation System and the EPA National Lakes Assessment.The team will then use the resulting lake temperature data to estimate changes in lake metabolism -- the absorption versus emission of carbon -- and seek to draw conclusions based on those estimates, such as differences based on region or specific characteristics of lakes."The goal is to close the loop between long-term changes in atmospheric carbon dioxide, leading to global temperature increases, leading to changes in lake water temperature, leading to changes in the role of lakes in the global carbon cycle," Rose said. "In other words, how much carbon dioxide is going to come out of lakes with more carbon dioxide in the atmosphere -- is there going to be positive feedback?"
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September 6, 2016
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https://www.sciencedaily.com/releases/2016/09/160906131436.htm
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Study demonstrates seasonality of bird migration in response to environmental cues
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A University of Oklahoma study demonstrates for the first time that remote sensing data from weather surveillance radar and on-the-ground data from the eBird citizen science database both yield robust indices of migration timing, also known as migration phenology. These indices can now be used to address the critical gap in our knowledge regarding the cues that migrants use for fine tuning their migration timing in response to climate.
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"These scientists combined citizen science observations with data from radar, satellites and weather predictions to understand the cues birds use in their migrations across continents," said Liz Blood, program director in the National Science Foundation's Division of Environmental Biology, which funded the research through NSF's MacroSystems Biology Program. "The results show that birds migrate in time with warming temperatures in spring and with seasonal changes in the surface of the land, like the leafing-out of trees."Seasonality of bird migration is shifting in response to climate change and, as a result, birds are arriving at their northern breeding grounds earlier in the spring. The OU study conducted in the eastern United States uses two novel data sources, weather surveillance radar and eBird citizen science data, to build indices of bird migration timing. These indices are innovative and reflect timing of migration of millions of birds of many species over large regions, expanding on more traditional measures of migration timing based on a few individuals of a particular species.OU researchers compared these new measures of migration with environmental cues that are thought to be used by birds to adjust migration timing. They found that temperature is likely to be useful to migrants in making adjustments in timing in route, however, they dispute the notion that a commonly used index of vegetation greenness is a useful cue for migration timing in the study region.OU Professors Jeffrey F. Kelly, Todd Fagin and Eli S. Bridge, Oklahoma Biological Survey, and graduate student Kyle G. Horton, Department of Biology, OU College of Arts and Sciences; in collaboration with OU Professors Phillip B. Chilson, School of Meteorology, and Kirsten de Beurs, Department of Geography and Environmental Sustainability, OU College of Atmospheric and Geographic Sciences; and Phillip M. Stepanian, formerly with the Advanced Radar Research Center, worked together to demonstrate how migration timing relates to land surface phenology and temperature changes."Understanding which environmental cues link migration timing to patterns of global change is key to forecasting future responses of migration systems," said Kelly. "Novel data sources from the weather surveillance radar network and the eBird citizen science database enable development of a migration phenology index that can be used to answer this question in future studies."
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September 6, 2016
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https://www.sciencedaily.com/releases/2016/09/160906085539.htm
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New tool can calculate renewable energy output anywhere in the world
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Researchers have created an interactive web tool to estimate the amount of energy that could be generated by wind or solar farms at any location.
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The tool, called Renewables.ninja, aims to make the task of predicting renewable output easier for both academics and industry.The creators, from Imperial College London and ETH Zürich, have already used it to estimate current Europe-wide solar and wind output, and companies such as the German electrical supplier RWE are using it to test their own models of output.To test the model, Dr Iain Staffell, from the Centre for Environmental Policy at Imperial, and Dr Stefan Pfenninger, who is now at ETH Zürich, have used Renewables.ninja to estimate the productivity of all wind farms planned or under construction in Europe for the next 20 years. Their results are published in the journal They found that wind farms in Europe current have an average 'capacity factor' of around 24 per cent, which means they produce around a quarter of the energy that they could if the wind blew solidly all day every day.This number is a factor of how much wind is available to each turbine. The study found that because new farms are being built using taller turbines placed further out to sea, where wind speeds are higher, the average capacity factor for Europe should rise by nearly a third to around 31 percent.This would allow three times as much energy to be produced by wind power in Europe compared to today, not only because there are more farms, but because those farms can take advantage of better wind conditions.In another research paper also published today in Wind and solar energies have a strong dependence on weather conditions, and these can be difficult to integrate into national power systems that requires consistency. If there is excess power generated by all energy sources, then some supplies have to be turned off.Currently, wind and solar power generators are the easiest to switch on and off, so they are often the first to go, meaning the power they generate can be wasted.Making use of a larger capacity for solar energy generation relies on changes to the national energy system, such as adding new types of electricity storage or small and flexible generators to balance the variable output from solar panels.Renewables.ninja uses 30 years of observed and modelled weather data from organisations such as NASA to predict the wind speed likely to influence turbines and the sunlight likely to strike solar panels at any point on Earth during the year.These figures are combined with manufacturer's specifications for wind turbines and solar panels to give an estimate of the power output that could be generated by a farm placed at any location.Dr Staffell said he spent two years crunching the data for his own research and thought that creating this tool would make it quicker for others to answer important questions: "Modelling wind and solar power is very difficult because they depend on complex weather systems. Getting data, building a model and checking that it works well takes a lot of time and effort."If every researcher has to create their own model when they start to investigate a question about renewable energy, a lot of time is wasted. So we built our models so they can be easily used by other researchers online, allowing them to answer their questions faster, and hopefully to start asking new ones."He and Dr Pfenninger have been beta testing Renewables.ninja for six months and now have users from 54 institutions across 22 countries, including the European Commission and the International Energy Agency.Dr Pfenninger said: "Renewables.ninja has already allowed us to answer important questions about the current and future renewable energy infrastructure across Europe and in the UK, and we hope others will use it to further examine the opportunities and challenges for renewables in the future."
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Weather
| 2,016 |
September 6, 2016
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https://www.sciencedaily.com/releases/2016/09/160906085016.htm
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Latest ocean warming review reveals extent of impacts on nature and humans
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Ocean warming is affecting humans in direct ways and the impacts are already being felt, including effects on fish stocks and crop yields, more extreme weather events and increased risk from water-borne diseases, according to what has been called the most comprehensive review available on the issue, launched today by the International Union for Conservation of Nature (IUCN) at the IUCN World Conservation Congress in Hawai'i.
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The report, Explaining ocean warming: Causes, scale, effects and consequences, reviews the effects of ocean warming on species, ecosystems and on the benefits oceans provide to humans. Compiled by 80 scientists from 12 countries, it highlights detectable scientific evidence of impacts on marine life, from microorganisms to mammals, which are likely to increase significantly even under a low emissions scenario."Ocean warming is one of this generation's greatest hidden challenges -- and one for which we are completely unprepared," says IUCN Director General Inger Andersen. "The only way to preserve the rich diversity of marine life, and to safeguard the protection and resources the ocean provides us with, is to cut greenhouse gas emissions rapidly and substantially."Ocean warming is already affecting ecosystems from polar to tropical regions, driving entire groups of species such as plankton, jellyfish, turtles and seabirds up to 10 degrees of latitude towards the poles, causing the loss of breeding grounds for turtles and seabirds, and affecting the breeding success of marine mammals, according to the report.By damaging fish habitats and causing fish species to move to cooler waters, warming oceans are affecting fish stocks in some areas and are expected to lead to reduced catches in tropical regions, the report states.In East Africa and the Western Indian Ocean, for example, ocean warming has reduced the abundance of some fish species by killing parts of the coral reefs they depend on, adding to losses caused by overfishing and destructive fishing techniques. In South-East Asia, harvests from marine fisheries are expected to fall by between 10% and 30% by 2050 relative to 1970-2000, as the distributions of fish species shift, under a high 'business as usual' greenhouse gas emission scenario, the report states."Most of the heat from human-induced warming since the 1970s -- a staggering 93% -- has been absorbed by the ocean, which acts as a buffer against climate change, but this comes at a price. We were astounded by the scale and extent of ocean warming effects on entire ecosystems made clear by this report," says Dan Laffoley, Marine Vice Chair of the World Commission on Protected Areas at IUCN, and one of the lead authors.The report also highlights evidence that ocean warming is causing increased disease in plant and animal populations, and impacting human health as pathogens spread more easily in warmer waters, including cholera-bearing bacteria and harmful algal blooms that cause neurological diseases like ciguatera.Warming oceans are also affecting the weather, with a range of knock-on effects on humans. The number of severe hurricanes has increased at a rate of around 25-30% per degree of global warming, the report states.Ocean warming has led to increased rainfall in mid-latitudes and monsoon areas, and less rain in various sub-tropical regions. These changes will have impacts on crop yields in important food-producing regions such as North America and India, according to the report.The protection against climate change offered to us by oceans and their ecosystems -- such as absorbing large amounts of CO2 and sheltering us from storms and erosion -- is also likely to reduce as the ocean warms, according to the report.The report's recommendations include recognising the severity of ocean warming impacts on ocean ecosystems and the benefits they provide to humans, expanding marine protected areas, introducing legal protection for the high seas, better evaluating the social and economic risks associated with warming oceans and continuing to fill gaps in scientific knowledge, as well as cutting greenhouse gas emissions rapidly and substantially.Ocean conservation is one of the major themes addressed by the ongoing IUCN Congress, where IUCN Members will vote on motions related to protecting the high seas and protected areas in Antarctica among many others.
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Weather
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September 5, 2016
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https://www.sciencedaily.com/releases/2016/09/160905114816.htm
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Detecting forest fragility with satellites
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Over the past decades forests in different parts of the world have suffered sudden massive tree mortality. Now an international team of scientists led by researchers from Wageningen University in the Netherlands has found a way to spot from satellite images which forests may be most likely to fall prey to such die-off events.
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"Tree cover is one of the most defining aspects of landscapes," says Jan Verbesselt, lead-author and a specialist in remote sensing. "It is therefore remarkable how poorly we can predict where trees are most likely to succumb to drought and other stresses. However, our planet is permanently monitored by satellites in detail, and we are proposing a new way to use that information for detecting the fragility of ecosystems to environmental perturbations.For the first time we were able to derive evidence for such changes from long-term satellite time series observations of tropical forests. Martin Herold emphasis: "Global satellite archives are getting longer and denser every day. Together with free and open archived data, this provides a rich source of information that only now is starting to be used for tropical forest resilience analysis over large areas and increasing time spans.""The basic idea is simple" says Marten Scheffer, who leads the research program on resilience of complex systems. "As a system loses resilience it becomes slower to recover from small perturbations. This also happens as a system approaches a tipping point. Now we found that the natural fluctuation in greenness of forests, as driven by weather changes, may actually reflect such slowness. This is the first time, we are able to generate indicators that can anticipate the fragility of forests to future climate changes and disturbances."
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Weather
| 2,016 |
September 5, 2016
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https://www.sciencedaily.com/releases/2016/09/160905114521.htm
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During drought, dry air can stress plants more than dry soil
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Newly published research by Indiana University scientists finds that low relative humidity in the atmosphere is a significant, growing and often under-appreciated cause of plant stress in hot, dry weather conditions.
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The finding suggests that models used to gauge the impact of drought on ecosystems should be refined to more accurately account for the role of low atmospheric humidity. It will become more important in the future, as the Earth's climate grows warmer and lower humidity has an increasing impact.And as these humidity levels fall, plants may become less effective at removing carbon from the atmosphere, reducing their ability to offset climate change. At the same time, agricultural management strategies like irrigation, which improve soil moisture but have a smaller effect on humidity, may become less effective in the future."There is much uncertainty when it comes to our ability to predict future patterns of carbon uptake by plants," said Kimberly Novick, assistant professor in the IU Bloomington School of Public and Environmental Affairs and the lead author of the study. "A lot of that uncertainty is related to an incomplete understanding of how ecosystems respond to drought."Our work suggests that properly specifying how plants respond to variations in atmospheric humidity is one way to reduce this uncertainty."The study, "The increasing importance of atmospheric demand for ecosystem water and carbon fluxes," was published in the journal Dry weather affects plants in two basic ways: via changes in moisture in the soil and relative humidity in the atmosphere. Think of it as a supply-and-demand situation, Novick said. Soil moisture supplies water to plants; during drought, it supplies less. Low relative humidity creates a "demand" that pulls water from plants; during drought, the dry atmosphere demands more water.Plants have evolved to close their stomates -- tiny pores on the surface of their leaves -- during dry weather to prevent the loss of excessive moisture. But plants also uptake carbon dioxide from the atmosphere through their stomates. When the stomates close, they capture less carbon.Before this study, it had been difficult to know how much of plants' response to drought was because of low soil moisture and how much was because of low relative humidity. Climate models tended to rely on soil moisture, which is easy to measure and to manipulate experimentally -- even though plant scientists know that low relative humidity could have an important, independent effect.Novick, Ficklin and their colleagues were able to separate the effects of soil moisture and relative humidity by analyzing data collected in hourly increments from 38 "flux towers" in the AmeriFlux Network, a collection of sites in various ecosystems that collect important micro-meteorological data every hour, and share these data with other researchers. While soil moisture changes little over the course of a day, humidity can vary significantly, allowing for the effects of soil moisture and humidity to be independently assessed using these "high-frequency" data.One of the flux towers, in Morgan-Monroe State Forest north of Bloomington, is operated by a team led by Novick and Phillips in cooperation with the Indiana Department of Natural Resources.The analysis found that soil moisture and relative humidity have markedly different influences on plant functioning at different times of the day. Over time, humidity tends to be the dominant influence as weather grows hotter and drier, especially in temperate forest ecosystems that are especially important in removing carbon dioxide from the atmosphere.In addition to having important implications for the management of agricultural systems, including row crops and forests, the findings may help scientists anticipate future effects of climate change, Novick said.Although the study doesn't focus on carbon fluxes, scientists know that plants remove less carbon from the atmosphere when their stomates are closed to reduce water loss. Thus, as the climate gets hotter and dryer, plants will become less capable of taking in carbon, which will lessen their ability to counteract climate change. Testing this hypothesis forms the foundation of ongoing work being conducted by the study's authors.
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Weather
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September 2, 2016
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https://www.sciencedaily.com/releases/2016/09/160902111408.htm
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New light on the complex nature of 'hot Jupiter' atmospheres
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Fascinating new light could be shed on the complex atmospheres of planets which orbit stars outside our own solar system, thanks to pioneering new research.
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A team of international researchers, led by astrophysicists from the University of Exeter, Columbia University and NASA Goddard Institute for Space Studies, used state-of -the-art modelling techniques to extensively study the atmosphere of a 'hot Jupiter' found 150 lightyears from Earth.The scientists adapted the state-of-the art computer model used by the Met Office to study Earth's atmosphere to perform simulations of these exotic distant worlds that are the size of Jupiter, but orbiting more closely to their parent star than Mercury does to the Sun.The results were compared to observations carried out using the powerful Spitzer Space Telescope, probing our understanding of the conditions within the atmospheres of these planets.The research revealed results that were largely consistent with existing observations, most notably around the effect of heat transport in the upper atmospheres of the exoplanets where extreme velocity winds carry heat so rapidly that the hottest part of the atmosphere is shifted away from the closest point to the star, where it would be expected to be.However, the study also revealed some intriguing discrepancies, including significant differences between the observed and expected brightness of the hot Jupiter's `nightside' -- or the hemisphere facing away from the star.The team are now calling on further studies to be conducted to unlock the secrets of how these planets evolve in such close proximity to their host.Dr Nathan Mayne, Senior Lecturer in Astrophysics at the University of Exeter and one of the authors of the study said: "This research is not only important in developing our understanding of this exotic class of planets, but also represents the first steps to building a deeper understanding of how planetary atmospheres and climates work across a range of conditions, including those more conducive to life."Additionally, over a longer timescale, by keeping close connection between astrophysicists and climate researchers, this programme will aid in the understanding of our own changing climate."The Met Office weather and climate prediction model is one of the most advanced models of its kind. However, this research applies this model to a planet with conditions far from that present on Earth, with temperatures exceeding one thousand degrees and an atmosphere spanning pressures orders of magnitude larger.A key finding of this research indicates that there is still no clear understanding of how the material that is moving from the hot dayside of the planet onto the cold nightside both cools and alters it chemical composition.Additionally, the team found intriguing hints that the deeper atmosphere, inaccessible to observations, supports large-scale, slow moving circulations potentially altering the temperature structure deep in the hot Jupiter's atmosphere.Dr David S. Amundsen, formerly of the University of Exeter and now at Columbia University and NASA Goddard Institute for Space Studies in the USA, and lead author of the paper added: "Models such as the UM uniquely allows us to study in great detail how the atmospheres of these planets change depending on different factors such as irradiation, composition and rotation. These models are becoming increasingly important to understand the continuously improving observations that are now starting to reveal the complex three-dimensional nature of these atmospheres."The UK Met Office GCM with a sophisticated radiation scheme applied to the the Jupiter HD209458 is published in
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Weather
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September 2, 2016
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https://www.sciencedaily.com/releases/2016/09/160902105846.htm
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'Tug of war' keeps scientists working on storm tracks
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Storm tracks -- regions where storms travel from west to east across oceans and continents driven by the prevailing jet stream -- determine weather and climate in middle-latitude places like Chicago and New York.
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"Changes in the position of storm tracks in response to anthropogenic climate change depend on how the equator-to-pole temperature gradient will change, and among the various factors affecting this gradient, cloud changes stand out as one of the important pieces of the puzzle," said Tiffany S. Shaw, assistant professor in geophysical sciences at the University of Chicago. She is the lead author of "Storm track processes and the opposing influences of climate change," a review of the latest research and current knowledge that was published Aug. 29, 2016, in In idealized and comprehensive climate model simulations, warming due to increased carbon dioxide concentration in the atmosphere leads the clouds in high latitudes to reflect more solar radiation, thereby cooling the earth's surface in those regions and increasing the temperature gradient between the equator and the poles. In isolation (the amount of solar energy reaching the Earth's surface) this would lead to a poleward shift of the storm tracks. Meanwhile, those same clouds tend to enhance the greenhouse effect, thereby warming the Earth's surface in those same regions and decreasing the temperature gradient between the equator and the poles, producing an opposite shift (also, in isolation).This is but one example of the opposing influences noted by the authors. Other examples include the opposing influence of warming in the tropical upper atmosphere and Arctic amplification (enhanced surface warming in the Arctic), both of which occur in models in response to climate change."The opposing cloud influences on the equator-to-pole gradient should be studied in more detail to understand the ultimate outcome of this 'tug of war,' as it relates to the future position of the storm tracks," Shaw said.The most important message of this paper is that scientists are currently unable to satisfactorily project the response of storm tracks to anthropogenic climate change, said Edwin Gerber, associate professor of mathematics and atmosphere ocean science at New York University's Courant Institute, who was not involved in the "We understand a great deal about the processes that are important to storm tracks, but the devil is in how they interact with each other. The authors hit the nail on the head when they describe it as a 'tug of war' between different forces, and it's uncertain which will win out."The researchers called for expanding observational efforts and the hierarchy of computer simulations used to understand how storm tracks will shift in response to the increased concentration of carbon dioxide in the atmosphere."In order to have confidence in our projected changes, we need to expand our hierarchy of models to include simplified models with cloud processes that can be used to study their impact on the storm tracks," Shaw said.Ultimately, any major changes in the position of storm tracks will have a significant impact on society because storm tracks shape temperature, precipitation, and extreme weather.Such shifts in position have the potential to significantly change patterns of rain, snow, heat waves and cold outbreaks, Gerber said. For example, if storm tracks shift poleward, New York and Chicago will likely experience warmer weather and less snow. And there's already evidence that the shift of the austral storm track southward -- which was caused by the ozone hole at the south pole -- has impacted rain in Australia and South America, he said."We need to know how extreme events will change in response to fossil fuel emissions so we can make informed decisions about our future use of fossil fuels," Gerber said.The "This paper nicely sets forth the 'state of the art' in our knowledge of storm tracks, as well as some of our most promising ideas for making progress in the future," Gerber said. "We need to know how the global circulation will change if we want to make accurate regional climate change predictions."I don't like throwing the dice when it comes to my children's future," he added. -- Greg Borzo
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Weather
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September 1, 2016
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https://www.sciencedaily.com/releases/2016/09/160901102740.htm
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Freshening of the Southern Ocean
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Long-term measurements of the salinity in the Southern Ocean have revealed a strong freshening signal over the past decades. In fact, these salinity changes are among the most pronounced in the global ocean. To date, the source of these changes has remained a conundrum.
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A newly published study in the scientific journal In their study, the scientists describe for the first time that the sea-ice conveyor belt around Antarctica has strengthened substantially, and that the associated freshwater fluxes to the open Southern Ocean can explain the Southern Ocean salinity distribution and its recent changes. This conveyor belt consists of the formation of sea ice along the Antarctic coast, thereby fixing water in ice, the northward transport of this frozen water, and the subsequent release of this water upon melting at the sea-ice edge.It may seem paradoxical, but while the sea ice in the Arctic is rapidly shrinking, the sea ice surrounding the Antarctic continent is actually expanding, despite global warming. Satellite observations show that the maximum ice cover in the Southern Ocean now extends further north than it did 30 years ago. This expansion is mainly due to a stronger transport of sea ice that has pushed the sea-ice edge further to the north.The new study unveils the substantial consequences for the ocean's salinity: Antarctic sea ice forms and melts every year. At the time of its maximum extent, it covers an area of 18 million square kilometres -- roughly the combined land area of the USA and Canada.During the freezing process, the salt in the sea water is rejected, thereby increasing the salinity of the remaining sea water. When the ice melts, the fresh water is released back into the ocean, thus freshening it. The ice mostly forms close to the coast of Antarctica.Strong winds and ocean currents then drive the sea ice more than 1,000 km northwards across the open sea. The northernmost edge of the sea ice is located roughly at 60 degrees south. This is where the ice starts to melt in the spring, releasing freshwater into the ocean.The cold meltwater that enters the sea water cools and freshens the ocean surface. Driven by the winds and other factors, this modified water mass then sinks below the warmer surface waters to form what is known as the Antarctic Intermediate Water, which has a comparatively low salinity. At depths of about 600 to 1,500 metres, this water spreads as a tongue to the north with its tip stretching as far as the Equator, and in the eastern Atlantic even as far as the coast of the Iberian peninsula."Our research demonstrates that the low salinity of the Antarctic Intermediate Water can be mostly explained by the freshwater released from the sea ice," says Dr Matthias Muennich, who is lecturer in physical oceanography at ETH Zurich and has been deeply involved in the study."The amount of freshwater released from the sea ice into the open ocean surface waters and the Antarctic Intermediate Water has increased significantly in past decades. For the first time, we have been able to quantify these changes, which are presumably caused by stronger southerly winds during this period," says the lead author of the study, Alex Haumann, a doctoral student in the Environmental Physics group and the Center for Climate Systems Modeling at ETH Zurich.According to their calculations, Alex Haumann and his colleagues estimated that the transport of freshwater by the sea ice has increased by up to 20 percent over the period 1982 to 2008. This would have caused a freshening of the sea water in the melt zone by as much as 0.02 grams per kilogramme of sea water per decade. "This figure is compatible with long-term records," says Nicolas Gruber, Professor of Environmental Physics at ETH Zurich and Alex Haumann's Ph.D. advisor."Research conducted over many years has shown that the Antarctic Intermediate Water has been freshening strongly," he explains. Scientists had assumed, however, that this phenomenon was due to the increased rainfall over the Southern Ocean. "But the changes in rainfall reconstructed in the weather and climate models are far too small to be able to explain the observed freshening." The ETH professor is therefore confident: "It must be the increased northward transport of freshwater by the sea ice that is largely responsible for this change."The sea ice affects not only the salinity of the sea water, but also its stratification. Water with a low salinity is lighter than more salty waters, and therefore floats at the surface. So if the surface water becomes fresher and thus lighter, it is more difficult for the saltier and heavier deep water to rise to the surface.This makes the vertical stratification of the water masses more stable. In turn, the stratification determines how the different water masses interact with each other and with the atmosphere to take up greenhouse gases, such as carbon dioxide, and heat."A more stable stratification could theoretically lead to a stronger uptake of carbon dioxide by the Southern Ocean, because less deep water that is rich in CO2, rises to the surface, where it releases carbon dioxide to the atmosphere," Professor Gruber explains. In the case of heat, the reverse situation would apply: a more stable ocean would actually absorb less heat.For a long time, researchers assumed that the exchange of heat and carbon dioxide was controlled mainly by changes in the strong winds that are typical of this region. However, the research conducted by Professor Gruber's group shows that the system is far more complicated. Changes to the sea ice around the Antarctic could play a much more important role than previously thought."In the past we have given far more attention to the sea ice changes in the Arctic because it is shrinking so dramatically. In the long term, however, changes in the Antarctic could be far more important for our climate, as they have a major influence on the planet's surface heat balance and the atmospheric carbon dioxide levels," says Alex Haumann.It is not clear yet whether the southerly winds have strengthened due to anthropogenic climate change or whether these are simply natural variations. "If these changes were human-made, this would be a dramatic consequence of human activity on the climate and ecosystem in one of the most remote and, so far, most pristine regions of Earth."So far, the Southern Ocean has acted as a climate regulator and carbon sink: climate models show that this ocean has absorbed around three quarters of the excess heat. The Southern Ocean has also taken up around half the total amount of anthropogenic carbon dioxide absorbed by the world's oceans.
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Weather
| 2,016 |
August 31, 2016
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https://www.sciencedaily.com/releases/2016/08/160831103023.htm
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Lightning strikes: Thunderstorms spread mercury pollution
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In the southern United States, an afternoon thunderstorm is part of a regular summer day. But new research shows those storms might be doing more than bringing some scary thunder and lightning. In fact, these storms are moving significant amounts of mercury to the ground.
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In a new study published in the journal Holmes and a team of researchers collected rain in a variety of locations in Florida, as well as Vermont, Georgia and Wisconsin. They then matched it to weather data that told them whether it was from a thunderstorm or just rain. They also used radar and satellite data to examine storm clouds. In a regular rainstorm, clouds are only a few kilometers thick. In a thunderstorm, they reach about 15 kilometers thick. Researchers found that more mercury was in rain from the clouds that reached the highest altitudes."The highest concentrations occurred during thunderstorms and the lowest during a regular rainstorm," Holmes said.For the last 20 years, the Mercury Deposition Network has recorded mercury content of precipitation across the United States. During this period, the states bordering the Gulf of Mexico have consistently seen the highest mercury deposition in the eastern U.S., typically double that of the northeast states.Typically, the Southeast sees a high number of thunderstorms in the summer months. Holmes and his colleagues believe that this is the reason the Southeast has higher levels of mercury in rain.Mercury is a naturally occurring chemical element that is used in several devices such as thermometers, barometers, fluorescent lamps and other devices. Exposure to high levels of mercury can be dangerous though. Holmes said now that researchers know that the storms are spreading the mercury, they need to understand why there are high amounts of mercury at these higher altitudes and how it affects Earth."We're trying to understand how mercury enters ecosystems in the U.S. and how it can affect people and wildlife," Holmes said.
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Weather
| 2,016 |
August 29, 2016
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https://www.sciencedaily.com/releases/2016/08/160829122244.htm
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Researchers unravel process for the formation of rainstorms
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Violent thunderstorms can often cause torrential rain, which pose a threat for both humans and the infrastructure. Until now such extreme weather phenomena have been very poorly understood. However, using advanced simulations for cloud systems, researchers also from the Niels Bohr Institute have determined how complex cloud systems build up in the atmosphere, which then interact with each other and strengthen the further build up of heavy rain and severe thunderstorms. The results are published in the scientific journal,
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Using high-resolution cloud models, researchers from the Max Planck Institute for Meteorology in Hamburg, the Swedish Meteorological and Hydrological Institute in Norrköping and the Niels Bohr Institute at the University of Copenhagen analysed how heavy rainfall is affected by rising temperatures. The simulations were performed over an area that typically constitutes a single field area in climate models, that is, an area of 200 km x 200 km. In the high-resolution cloud model the area is divided into smaller areas of 200 meters, resulting in a 1000 times greater resolution. The high resolution made it possible for the researchers to uncover the processes taking place in the atmosphere, which are only included in global climate models to a very approximate degree."To detect the physical process that form, for example, storm clouds, we use simulations that are capable of revealing local thermal and moisture variations, which give rise to so-called 'convective' clouds. Convection is the process that forms, for example, thunderstorm clouds. Due to the heating of the surface in connection with sufficient humidity, a warm updraft is released in the atmosphere. Traditional climate models do not see these processes to an adequate degree. It is interesting how systematically convective clouds occur. Where two clouds collide, new and stronger clouds often appear," explains Jan O. Haerter, researcher at the Niels Bohr Institute at the University of Copenhagen.The simulations in the atmosphere build up a state of organisation that the researchers describe as a kind of 'memory'."What we see here is a so-called complex system. The way the atmosphere behaves is not only influenced by large scales, but is also due to what we call self-organisation. Convective clouds come and go within a certain period. Over the course of the day, these periods increase and so does the intensity of rain," explains Jan O. Haerter.Their results show that heavy rain is produced when multiple clouds collide and thus interact with each other. Without these collisions between clouds, the rain remains light.Isolated rain showers show no change in intensity with increasing temperatures, but rising temperatures lead to more frequent collisions of convective cloud systems. The researchers compare this dynamic to that of small streams merging to form larger rivers -- in an analogous way collisions between cloud systems can result in heavier rain.The new results therefore contradict the traditional global climate models where convective clouds are seen as being independent of each other.In previous studies, the researchers discovered that heavy, thunderous rain showers that are often seen during summer in temperate latitudes were much more sensitive to temperature than expected.The researchers found that when the temperature rose, these high clouds behaved very differently from the clouds that were spread over large areas, but they could not determine the main reason for the increased rainfall from the measurements alone."With the new model calculations, we are getting a better understanding of the intense thunderstorms that can lead to the severe flooding that often occurs in temperate latitudes," explains Jan O. Haerter.
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Weather
| 2,016 |
August 26, 2016
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https://www.sciencedaily.com/releases/2016/08/160826162146.htm
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A better way to predict the weather on sea and over land
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Scientists at the Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin-Madison have made new updates to old technology that will enable weather forecasters to make improved predictions of severe weather.
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The new capability is based on an algorithm CIMSS scientists Tony Wimmers and Chris Velden developed nearly a decade ago to better equip satellites to measure "total precipitable water" (TPW), the total amount of water vapor contained in a column of moist air from the Earth's surface to the very top of the atmosphere. That algorithm allowed measurements solely above the sea, but now TPW values can be measured over land, too.By measuring TPW, forecasters learn how much moisture in a given column of moist air could potentially become rain or snow. It is an especially important metric for predicting and tracking tropical cyclones and other severe weather in the humid tropics.In 2003, Wimmers and Velden sought to fill in the time gaps in TPW data already collected by polar-orbiting satellites, which gather swaths of information from above the Earth's surface roughly every one-to-18 hours. They wanted to create an algorithm that would apply an existing technique to TPW data, but the technique had only ever been used for flat values, not for volume, such as a column of TPW."I didn't think it would work," says Wimmers, the lead developer for the project, called the Morphed Integrated Microwave Imagery at CIMSS -- Total Precipitable Water, or MIMIC-TPW. "But, it turns out, it provides a very accurate approximation over the time gaps that we were filling in … I think it surprised everyone."Wimmers and Velden launched the first MIMIC-TPW algorithm in 2007 and it has been an integral tool for tropical weather analysis ever since. Still, there was room for improvement, particularly to better serve coastal forecasters.Some polar-orbiting satellites scan the Earth and collect data in a conical pattern, so while they are constantly changing position all over the globe, their retrievals are generated from the same scan angle. This allows them to take very precise measurements and stay well calibrated with other conical scanners, Wimmers explains, but it constrains TPW data collection to uniform surfaces like oceans. Land was simply too uneven, especially in locations with varied topography."It's a very simple algorithm that gives you a very fast retrieval of TPW over oceanic areas, says Wimmers. "But it doesn't generate retrievals over land."This was adequate for users like the U.S. Naval Research Laboratory -- a major source of support for MIMIC-TPW -- and other users generally interested in forecasting marine weather and tropical cyclone environments. But Wimmers and Velden hoped to find an alternative solution that could extend coverage to over land areas.Then, last year, they got their opportunity.The National Oceanic and Atmospheric Administration (NOAA) made significant improvements in the TPW retrieval from its microwave-scanning satellites, called the Microwave Integrated Retrieval System (MIRS). While lower in overall resolution, these satellites provide more comprehensive coverage than conical-scanning satellites."Since this is a full atmospheric retrieval system, it works over all surfaces, including land," says Wimmers.He and Velden made changes to the MIRS algorithm, a technique they refer to as "morphological compositing." It uses TPW data from every available operational microwave-frequency satellite sensor, extending MIMIC-TPW's coverage above and beyond the original design, providing TPW values over land and sea for the entire globe."We adapted the image-morphing algorithm to work over water and land, and applied it to a more formal coordinate system," says Wimmers. "What we were doing before was essentially a shortcut -- it only needed to apply to the tropics. This new method makes it work in global coordinates."The algorithm uses data from seven microwave instruments from U.S. military, NOAA, Japanese and European satellites. Then it incorporates wind values from the National Weather Service's global weather model -- the Global Forecast System (GFS) -- and accounts for water vapor motion. The algorithm can "push" the data forward from the time of the measurement about one-to-10 hours or push it backward by the same time interval, Wimmers explains."That way, you can take one observation and make it apply to a long stretch of time," he says, though he cautions the technique needs "special care.""You have to make sure you are not violating too many assumptions about how water vapor moves, but it is a pretty simple process," Wimmers says.While the new MIMIC-TPW version is not yet fully operational (it has only been online a few weeks) the team has already received requests for case study imagery, some of which predate its release, such as a severe flooding event in South Carolina last fall. The data should be more useful for a variety of interested users."This is very encouraging. It shows us we are on the right track," Wimmers says. "It's a very good sign that people (forecasters) are that interested in it, and we can start to take it in new directions."MIMIC-TPW 2.0 will most likely be operational in the fall of 2016.
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Weather
| 2,016 |
August 25, 2016
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https://www.sciencedaily.com/releases/2016/08/160825214336.htm
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More to rainbows than meets the eye
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In-depth review charts the scientific understanding of rainbows and highlights the many practical applications of this fascinating interaction between light, liquid and gas.
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There's more to rainbows than meets the eye. Knowledge gained from studying these multicoloured arcs of scattered light can be incredibly useful in ways that may not immediately spring to mind. Rainbow effects can warn of chemical contamination in the atmosphere, help to develop more efficient combustion engines and possibly even provide insight into the mechanics of reinforced concrete.Writing in Haußmann has been studying rainbows for more than 20 years. His interest began at school where he and his friends would log meteorological data for fun to keep tabs on changes in the weather. Today, weather watching has become more sophisticated with the introduction of techniques such as radar remote sensing, but observing rainbows remains important. As Haußmann points out, these patterns of scattered light can provide considerable clues to the size distribution and shape of raindrops falling during wet weather. If paired with radar data, this information could be used to quantify the amount of rainwater reaching the ground. "If our analysis methods are precise enough, we can turn rainbows into optical remote sensing tools to study the physics of rain," he comments.Haußmann's review delves deep into the challenges of simulating rainbows as mathematical modeling is an important tool in furthering our understanding of this field. There are some key points that add to the puzzle. "Rain drops are not exactly spherical, but become deformed into slightly flattened 'hamburger bun' shapes due to air drag as they fall through the sky," he explained. "This has a drastic influence on the appearance of rainbows and makes scattering calculations numerically very demanding."As well as focusing on the science, the article also provides tips for capturing rainbows on camera, which could help to win bragging rights on Instagram and other popular photo-sharing websites. "Rainbows are short-lived and special phenomena such as twinned bows are pretty rare, so it's important to always have your camera to hand," recommends Haußmann. "This can be a smartphone or, in my case, an SLR camera with a fisheye lens to capture the full width of a rainbow in a single frame."
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Weather
| 2,016 |
August 24, 2016
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https://www.sciencedaily.com/releases/2016/08/160824212223.htm
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By mid-century, more Antarctic snowfall may help offset sea-level rise
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When Antarctica's air temperature rises, moisture in the atmosphere increases. That should mean more snowfall on the frozen continent. So why hasn't that trend become evident in Antarctica's surface mass balance as climate models predict?
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In a new study, scientists used historical records and climate simulations to examine that question. They found that the effect of rising temperatures on snowfall has so far been overshadowed by Antarctica's large natural climate variability, which comes from random, chaotic variations in the polar weather. By mid-century, however, as temperatures continue to rise, the study shows how the effect of human-induced warming on Antarctica's net snow accumulation should emerge above the noise.The expectation of more snowfall is something of a silver lining as temperatures rise. Global warming is already increasing sea level through melting ice and thermal expansion. The increase in snowfall over Antarctica could help reduce the amount of global sea level rise by 51 to 79 millimeters, or about 2 to 3 inches, by the year 2100, according to the study. That would be a small but important benefit: the Intergovernmental Panel on Climate Change estimates global sea level rise will be at least 10 times that by 2100 under the same high-emissions scenario used in the new study."Increased snowfall over Antarctica is the sole process connected to global warming that is thought to have a significant mitigating effect on global sea level rise," said lead author Michael Previdi, a professor at Columbia University's Lamont-Doherty Earth Observatory. "While the magnitude of this effect is uncertain, it is likely that the balance of different processes determining Antarctica's net contribution to global sea level rise will be decidedly different in the future than it has been in the recent past."On a continental scale, surface mass balance is the difference between the amount of snowfall that accumulates and the amount of snow lost to sublimation. It affects global sea level because the amount of water on earth is essentially constant, so when more water is stored as snow or ice on land, less water is available to contribute to rising seas.For the study, published this week in the journal The models allow scientists to quantify both the human influence on surface mass balance and the influence of natural variability. The scientists found that from 1961 to 2005, global warming increased Antarctica's surface mass balance by 124 billion tons per year, smaller in magnitude than natural year-to-year variability, which was found to be plus or minus 126 billion tons per year.When the scientists looked at all 35 models, 46 percent of the individual simulations showed a statistically significant trend in surface mass balance from 1961 to 2005, the year that most of the models' historical simulations end. The likelihood of seeing a statistically significant trend in surface mass balance rises as the models forecast ahead in time. After 2015, the models cross a threshold where it becomes "likely," with a 66 percent chance, that evidence of anthropogenic climate change will emerge in Antarctica's surface mass balance. By 2040, it becomes "very likely," with a higher than 90 percent chance.Previdi and Polvani repeated their analysis with different emissions scenarios and also considered surface mass balance trends starting in 1979, at the dawn of the satellite era. The analyses showed similar results, with the global warming signal "very likely" to emerge by mid-century."The apparent discrepancy between models and observations can be easily reconciled by considering the large surface mass balance variations generated naturally within the Antarctic climate system," they write.Previous studies also found no significant change in the total Antarctic surface mass balance in recent decades, though a 2013 ice core study found a 10 percent increase in surface mass balance in coastal regions since the 1960s. All temperature records, meanwhile, indicate that Antarctica warmed from 1961 to 2005. Ice cores also show a strong relationship between the continent's surface mass balance and temperature changes through history, including the end of the last ice age when temperatures rose dramatically.
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Weather
| 2,016 |
August 24, 2016
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https://www.sciencedaily.com/releases/2016/08/160824212216.htm
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Climate analysis makes sense of Antarctic puzzle
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Researchers caution that global warming signals are being masked by random weather variations and report that the human influence on snowfall levels will become detectable within the next few decades.
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In a warmer world, scientists expect to see an increase in snowfall over the Antarctic because of higher levels of moisture in the air. This is expressed in global and regional climate models as an increase in surface mass balance (SMB) -- a term that incorporates the loss of mass in the Antarctic ice sheet through sublimation and the gain in mass due to snowfall.However, so far -- and contrary to robust projections -- observations have failed to detect any such increase in net snow accumulation in the region in recent times. Reporting their findings in the journal "The long-term SMB trend due to global warming in recent decades is small compared to the natural variability of SMB that arises from random, chaotic variations in the weather," explained Michael Previdi of Columbia University, who performed the study together with his colleague, Lorenzo Polvani. "As a result, these random weather variations could have effectively 'masked' the global warming signal, thus preventing any long-term SMB trend from being detected in the observations."Their conclusions are based on the analysis of 35 different climate models, which allow the researchers to quantify i) the human influence on Antarctic SMB and ii) the natural variability of SMB that arises from random, chaotic variations in the weather."We believe that the human influence on Antarctic SMB will become detectable within the next few decades," said Previdi. "This is of critical societal importance since increases in snowfall in the region will have a mitigating effect on future global sea-level rise."Full details on the work can be found in the open access journal
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Weather
| 2,016 |
August 24, 2016
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https://www.sciencedaily.com/releases/2016/08/160824144031.htm
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Global climate models do not easily downscale for regional predictions
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One size does not always fit all, especially when it comes to global climate models, according to Penn State climate researchers.
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"The impacts of climate change rightfully concern policy makers and stakeholders who need to make decisions about how to cope with a changing climate," said Fuqing Zhang, professor of meteorology and director, Center for Advanced Data Assimilation and Predictability Techniques, Penn State. "They often rely upon climate model projections at regional and local scales in their decision making."Zhang and Michael Mann, Distinguished professor of atmospheric science and director, Earth System Science Center, were concerned that the direct use of climate model output at local or even regional scales could produce inaccurate information. They focused on two key climate variables, temperature and precipitation.They found that projections of temperature changes with global climate models became increasingly uncertain at scales below roughly 600 horizontal miles, a distance equivalent to the combined widths of Pennsylvania, Ohio and Indiana. While climate models might provide useful information about the overall warming expected for, say, the Midwest, predicting the difference between the warming of Indianapolis and Pittsburgh might prove futile.Regional changes in precipitation were even more challenging to predict, with estimates becoming highly uncertain at scales below roughly 1200 miles, equivalent to the combined width of all the states from the Atlantic Ocean through New Jersey across Nebraska. The difference between changing rainfall totals in Philadelphia and Omaha due to global warming, for example, would be difficult to assess. The researchers report the results of their study in the August issue of "Policy makers and stakeholders use information from these models to inform their decisions," said Mann. "It is crucial they understand the limitation in the information the model projections can provide at local scales."Climate models provide useful predictions of the overall warming of the globe and the largest-scale shifts in patterns of rainfall and drought, but are considerably more hard pressed to predict, for example, whether New York City will become wetter or drier, or to deal with the effects of mountain ranges like the Rocky Mountains on regional weather patterns."Climate models can meaningfully project the overall global increase in warmth, rises in sea level and very large-scale changes in rainfall patterns," said Zhang. "But they are uncertain about the potential significant ramifications on society in any specific location."The researchers believe that further research may lead to a reduction in the uncertainties. They caution users of climate model projections to take into account the increased uncertainties in assessing local climate scenarios."Uncertainty is hardly a reason for inaction," said Mann. "Moreover, uncertainty can cut both ways, and we must be cognizant of the possibility that impacts in many regions could be considerably greater and more costly than climate model projections suggest."
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Weather
| 2,016 |
August 24, 2016
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https://www.sciencedaily.com/releases/2016/08/160824084643.htm
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Scientists begin to unravel summer jet stream mystery
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Scientists have discovered the cause of the recent run of miserable wet summers as they begin to unravel the mysteries of the Atlantic jet stream.
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Researchers from the University of Sheffield and The Met Office have identified a number of possible factors that may influence the Atlantic jet stream and therefore help to predict summer climate from one year to the next.The summer weather in the UK and northwest Europe is influenced by the position and strength of the Atlantic jet stream -- a ribbon of very strong winds which are caused by the temperature difference between tropical and polar air masses.A northward shift in the Atlantic jet stream tends to direct low-pressure systems northwards and away from the UK, leading to warm and dry weather during summer.But, if the summer jet slips southwards it can lead to the jet shifting the low-pressure systems directly over the UK, causing miserable weather like we experienced in the first half of this summer. The big question is "why does the jet stream shift?"The report, led by PhD student Richard Hall and Professor Edward Hanna from the University of Sheffield's Department of Geography, discovered that up to 35 per cent of this variability may be predictable -- a significant advance which may help in the development of seasonal forecasting models.Lead author of the study, Richard Hall, said: "There is nothing people in the UK like to discuss more than the weather. This is because it can fluctuate so drastically -- we can be basking in high temperatures and sunshine one week only to be struck by heavy downpours and strong winds the next."Our study will help forecasters to predict further into the future giving a clearer picture of the weather to come."The findings suggest the latitude of the Atlantic jet stream in summer is influenced by several factors including sea surface temperatures, solar variability, and the extent of Arctic sea-ice, indicating a potential long-term memory and predictability in the climate system.Edward Hanna, Professor of Climate Change at the University of Sheffield, said: "Working with The Met Office we were able to look at the different factors which may influence the jet stream, which paves the way for improvements in long-term forecasting."Professor Adam Scaife, Head of long range forecasting at the Met Office, said: "We've made big inroads into long-range forecasts for winter, but we are still limited to shorter-range weather forecasts in summer. Studies like this help to identify ways to break into the long-range summer forecast problem."The study, published in the journal Further research will seek to establish the physical mechanisms behind these links and identify the different influences that jet speed and latitude bring to bear on our summer weather.
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Weather
| 2,016 |
August 19, 2016
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https://www.sciencedaily.com/releases/2016/08/160819114213.htm
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NASA monitors the 'new normal' of sea ice
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This year's melt season in the Arctic Ocean and surrounding seas started with a bang, with a record low maximum extent in March and relatively rapid ice loss through May. The melt slowed down in June, however, making it highly unlikely that this year's summertime sea ice minimum extent will set a new record.
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"Even when it's likely that we won't have a record low, the sea ice is not showing any kind of recovery. It's still in a continued decline over the long term," said Walt Meier, a sea ice scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "It's just not going to be as extreme as other years because the weather conditions in the Arctic were not as extreme as in other years.""A decade ago, this year's sea ice extent would have set a new record low and by a fair amount. Now, we're kind of used to these low levels of sea ice -- it's the new normal."This year's sea ice cover of the Barents and Kara seas north of Russia opened up early, in April, exposing the surface ocean waters to the energy from the sun weeks ahead of schedule. By May 31, the extent of the Arctic sea ice cover was comparable to end-of-June average levels. But the Arctic weather changed in June and slowed the sea ice loss. A persistent area of low atmospheric pressure, accompanied by cloudiness, winds that dispersed ice and lower-than-average temperatures, didn't favor melt.The rate of ice loss picked up again during the first two weeks of August, and is now greater than average for this time of the year. A strong cyclone is moving through the Arctic, similar to one that occurred in early August 2012. Four years ago, the storm caused an accelerated loss of ice during a period when the decline in sea ice is normally slowing because the sun is setting in the Arctic. However, the current storm doesn't appear to be as strong as the 2012 cyclone and ice conditions are less vulnerable than four years ago, Meier said."This year is a great case study in showing how important the weather conditions are during the summer, especially in June and July, when you have 24 hours of sunlight and the sun is high in the sky in the Arctic," Meier said. "If you get the right atmospheric conditions during those two months, they can really accelerate the ice loss. If you don't, they can slow down any melting momentum you had. So our predictive ability in May of the September minimum is limited, because the sea ice cover is so sensitive to the early-to-mid-summer atmospheric conditions, and you can't foresee summer weather."As scientists are keeping an eye on the Arctic sea ice cover, NASA is also preparing for a new method to measure the thickness of sea ice -- a difficult but key characteristic to track from orbit."We have a good handle on the sea ice area change," said Thorsten Markus, Goddard's cryosphere lab chief. "We have very limited knowledge how thick it is."Research vessels or submarines can measure ice thickness directly, and some airborne instruments have taken readings that can be used to calculate thickness. But satellites haven't been able to provide a complete look at sea ice thickness in particular during melting conditions, Markus said. The radar instruments that penetrate the snow during winter to measure thickness don't work once you add in the salty water of the melting sea ice, since the salinity interferes with the radar.The Ice, Cloud and land Elevation Satellite-2, or ICESat-2, will use lasers to try to get more complete answers of sea ice thickness. The satellite, slated to launch by 2018, will use a laser altimeter to measure the heights of Earth's surface.In the Arctic, it will measure the elevation of the ice floes, compared to the water level. However, only about one-tenth of sea ice is above the water surface; the other nine-tenths lie below.To estimate the entire thickness of the ice floe, researchers will need to go beyond the above-water height measurements, and perform calculations to account for factors like the snow on top of the ice and the densities of the frozen layers. Scientists are eager to see the measurements turned into data on sea ice thickness, Markus said."If we want to estimate mass changes of sea ice, or increased melting, we need the sea ice thickness," he said. "It's critically important to understanding the changes in the Arctic."
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Weather
| 2,016 |
August 18, 2016
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https://www.sciencedaily.com/releases/2016/08/160818212759.htm
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Pacific sea level predicts global temperature changes
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The amount of sea level rise in the Pacific Ocean can be used to estimate future global surface temperatures, according to a new report led by University of Arizona geoscientists.
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Based on the Pacific Ocean's sea level in 2015, the team estimates by the end of 2016 the world's average surface temperature will increase up to 0.5 F (0.28 C) more than in 2014.In 2015 alone, the average global surface temperature increased by 0.32 F (0.18 C)."Our prediction is through the end of 2016," said first author Cheryl Peyser. "The prediction is looking on target so far."Scientists knew that both the rate at which global surface temperature is rising and sea level in the western Pacific varied, but had not connected the two phenomena, said Peyser, a UA doctoral candidate in geosciences."We're using sea level in a different way, by using the pattern of sea level changes in the Pacific to look at global surface temperatures -- and this hasn't been done before," she said.Peyser and her colleagues used measurements of sea level changes taken by NASA/NOAA/European satellites starting in 1993.Using sea surface height rather than sea surface temperatures provides a more accurate reflection of the heat stored in the entire water column, said co-author Jianjun Yin, a UA associate professor of geosciences."We are the first to use sea level observations to quantify the global surface temperature variability," Yin said.The team found when sea level in the western Pacific rises more than average -- as it did from 1998 to 2012 -- the rise in global surface temperatures slows.In contrast, when sea level drops in the western Pacific but increases in the eastern Pacific as it did in 2015, global surface temperatures bump up because the heat stored in the ocean is released, Yin said.The paper by Peyser, Yin, Felix Landerer of NASA's Jet Propulsion Laboratory, Pasadena, California, and Julia Cole, a UA professor of geosciences, titled, "Pacific Sea Level Rise Patterns and Global Surface Temperature Variability," is being published online in People already knew the tropical Pacific Ocean was relatively higher in the west -- the trade winds blow from east to west, piling up water on the western side of the Pacific.However, the degree of the tilt from west to east changes over time, much like a seesaw. Sometimes the western Pacific near Asia is much higher than the ocean's eastern coast with the Americas. At other times, Pacific sea level in the west is not much greater than sea level in the east.Others had documented that two different climate cycles, the Pacific Decadal Oscillation and the El Niño/La Niña cycle, affected how much the surface of the Pacific Ocean tilted from west to east.From 1998 to 2012, the rate at which the global surface temperature increased slowed down -- a phenomenon dubbed "the global warming hiatus." During the same time period, sea level in the western tropical Pacific Ocean increased four times faster than the average global sea level rise.Yin wondered if the two phenomena -- sea level and global surface temperature -- were related and asked Peyser, his graduate student, to investigate.To figure out whether there was a connection, Peyser used state-of-the-art climate models that show what the climate system would do in the absence of global warming.The models showed that changes in sea level in the western Pacific were correlated with changes in global surface temperature.Verifying the correlation allowed the researchers to calculate the numerical relationship between amount of tilt and global surface temperature.Once the researchers had the correlation, they used actual Pacific sea level data from satellites to calculate the Pacific Ocean's contribution to global surface temperature."What I found was that during years when the tilt was steep in the western Pacific, global average temperature was cooler," she said. "And when the seesaw is tilted more toward the eastern Pacific, it's warmer.""We could say that for a certain amount of change in the tilt, you could expect a certain change in the temperature," she said. "Natural variability is a really important part of the climate cycle."Understanding the variability is crucial for understanding the mechanisms underlying the warming hiatus, Yin said.During the global warming hiatus, more heat was being stored in the deeper layers of the western Pacific Ocean, muting warming at the surface, the researchers said. Because warmer water expands, that stored heat contributed to the extreme sea level rise in the western Pacific during that time.Starting in 2014 the ocean's tilt started to flatten out as the climate cycle changed to an El Niño pattern. The heat previously stored in the ocean was being released, warming Earth's surface and reducing sea level in the western Pacific.Yin was surprised to find the Pacific Ocean plays such an important role in the global surface temperature. He said, "Our research shows that the internal variability of the global climate system can conceal anthropogenic global warming, and at other times the internal variability of the system can enhance anthropogenic warming."The next step, he said, is figuring out the mechanisms that allow the Pacific to change the global surface temperature so quickly.
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Weather
| 2,016 |
August 15, 2016
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https://www.sciencedaily.com/releases/2016/08/160815185920.htm
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NASA analyzes deadly Louisiana flooding
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Record-setting rainfall and flooding in southern Louisiana have been calculated at NASA with data from satellites.
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An extremely severe rainfall event hit the states of Louisiana and southern Mississippi when a very slow moving low pressure system continuously pulled tropical moisture from the Gulf of Mexico.Measurements by the Global Precipitation Measurement or GPM mission core observatory satellite showed that rainfall intensity within the low pressure system actually increased on Aug. 12 as the low pressure area bringing the rainfall settled over southeastern Louisiana. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency JAXA.At least 4 people have died in record flooding after the unusually heavy rainfall starting falling the week of Aug. 8. More than 27 inches (686 millimeters (mm)) of rain have been reported in the area. This is the second time this year that record flooding rainfall has hit Louisiana. At least 27 inches (686 mm) of precipitation was also reported in Louisiana during the middle of Mar. 2016 and also caused record flooding.At NASA's Goddard Space Flight Center in Greenbelt, Maryland, NASA's Integrated Multi-satellite Retrievals for GPM (IMERG) data were used to make estimates of total rainfall over the northern Gulf of Mexico during the period from Aug. 8 to Aug. 15, 2016.The IMERG data showed heavy rainfall totals moving toward the northwest from the Florida Panhandle into the central northern Gulf coast. Over 20 inches (508 mm) of rainfall was estimated in large areas of southeastern Louisiana and extreme southern Mississippi. Even greater rainfall totals of 30 inches (762 mm) were indicated in a small area of Louisiana west of Lake Pontchartrain.Heavy rainfall and flooding is now predicted to occur northward into the Mississippi valley as tropical moisture continues to be transported northward and interacts with a nearly stationary frontal system. Heavy rainfall has also recently affected southeastern Texas and western Louisiana.The National Weather Service (NWS) in New Orleans, Louisiana noted in a forecast discussion on Aug. 15, "As historical and devastating river flooding continues over areas between Baton Rouge and Lake Maurepas, the weather has returned to a more typical summer pattern with isolated to scattered showers and thunderstorms developing with daytime heating."NWS also noted that several of the rivers in and around the greater Baton Rouge area still remain at high levels after peaking at record or major crests. NWS noted that several points downstream and close to Lake Maurepas still have a way to go before broad cresting. NWS New Orleans cautioned that some locations will also undergo backwater flooding well away from the main streams, so this event remains in full swing.
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Weather
| 2,016 |
August 15, 2016
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https://www.sciencedaily.com/releases/2016/08/160815185826.htm
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Van Allen probes catch rare glimpse of supercharged radiation belt
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Our planet is nestled in the center of two immense, concentric doughnuts of powerful radiation: the Van Allen radiation belts, which harbor swarms of charged particles that are trapped by Earth's magnetic field. On March 17, 2015, an interplanetary shock -- a shockwave created by the driving force of a coronal mass ejection, or CME, from the sun -- struck Earth's magnetic field, called the magnetosphere, triggering the greatest geomagnetic storm of the preceding decade. And NASA's Van Allen Probes were there to watch the effects on the radiation belts.
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One of the most common forms of space weather, a geomagnetic storm describes any event in which the magnetosphere is suddenly, temporarily disturbed. Such an event can also lead to change in the radiation belts surrounding Earth, but researchers have seldom been able to observe what happens. But on the day of the March 2015 geomagnetic storm, one of the Van Allen Probes was orbiting right through the belts, providing unprecedentedly high-resolution data from a rarely witnessed phenomenon. A paper on these observations was published in the Researchers want to study the complex space environment around Earth because the radiation and energy there can impact our satellites in a wide variety of ways -- from interrupting onboard electronics to increasing frictional drag to disrupting communications and navigation signals."We study radiation belts because they pose a hazard to spacecraft and astronauts," said David Sibeck, the Van Allen Probes mission scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who was not involved with the paper. "If you knew how bad the radiation could get, you would build a better spacecraft to accommodate that."Studying the radiation belts is one part of our efforts to monitor, study and understand space weather. NASA launched the twin Van Allen Probes in 2012 to understand the fundamental physical processes that create this harsh environment so that scientists can develop better models of the radiation belts. These spacecraft were specifically designed to withstand the constant bombardment of radiation in this area and to continue to collect data even under the most intense conditions. A set of observations on how the radiation belts respond to a significant space weather storm, from this harsh space environment, is a goldmine.The recent research describes what happened: The March 2015 storm was initiated by an interplanetary shock hurtling toward Earth -- a giant shockwave in space set off by a CME, much like a tsunami is triggered by an earthquake.Swelling and shrinking in response to such events and solar radiation, the Van Allen belts are highly dynamic structures within our planet's magnetosphere. Sometimes, changing conditions in near-Earth space can energize electrons in these ever-changing regions. Scientists don't yet know whether energization events driven by interplanetary shocks are common. Regardless, the effects of interplanetary shocks are highly localized events -- meaning if a spacecraft is not precisely in the right place when a shock hits, it won't register the event at all. In this case, only one of the Van Allen Probes was in the proper position, deep within the magnetosphere -- but it was able to send back key information.The spacecraft measured a sudden pulse of electrons energized to extreme speeds -- nearly as fast as the speed of light -- as the shock slammed the outer radiation belt. This population of electrons was short-lived, and their energy dissipated within minutes. But five days later, long after other processes from the storm had died down, the Van Allen Probes detected an increased number of even higher energy electrons. Such an increase so much later is a testament to the unique energization processes following the storm."The shock injected -- meaning it pushed -- electrons from outer regions of the magnetosphere deep inside the belt, and in that process, the electrons gained energy," said Shri Kanekal, the deputy mission scientist for the Van Allen Probes at Goddard and the leading author of a paper on these results.Researchers can now incorporate this example into what they already know about how electrons behave in the belts, in order to try to understand what happened in this case -- and better map out the space weather processes there. There are multiple ways electrons in the radiation belts can be energized or accelerated: radially, locally or by way of a shock. In radial acceleration, electrons are carried by low-frequency waves towards Earth. Local acceleration describes the process of electrons gaining energy from relatively higher frequency waves as the electrons orbit Earth. And finally, during shock acceleration, a strong interplanetary shock compresses the magnetosphere suddenly, creating large electric fields that rapidly energize electrons.Scientists study the different processes to understand what role each process plays in energizing particles in the magnetosphere. Perhaps these mechanisms occur in combination, or maybe just one at a time. Answering this question remains a major goal in the study of radiation belts -- a difficult task considering the serendipitous nature of the data collection, particularly in regard to shock acceleration.Additionally, the degree of electron energization depends on the process that energizes them. One can liken the process of shock acceleration, as observed by the Van Allen Probe, to pushing a swing."Think of 'pushing' as the phenomenon that's increasing the energy," Kanekal said. "The more you push a swing, the higher it goes." And the faster electrons will move after a shock.In this case, those extra pushes likely led to the second peak in high-energy electrons. While electromagnetic waves from the shock lingered in the magnetosphere, they continued to raise the electrons' energy. The stronger the storm, the longer such waves persist. Following the March 2015 storm, resulting electromagnetic waves lasted several days. The result: a peak in electron energy measured by the Van Allen Probe five days later.This March 2015 geomagnetic storm was one of the strongest yet of the decade, but it pales in comparison to some earlier storms. A storm during March 1991 was so strong that it produced long-lived, energized electrons that remained within the radiation belts for multiple years. With luck, the Van Allen Probes may be in the right position in their orbit to observe the radiation belt response to more geomagnetic storms in the future. As scientists gather data from different events, they can compare and contrast them, ultimately helping to create robust models of the little-understood processes occurring in these giant belts.The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, built and operates the Van Allen Probes for NASA's Heliophysics Division in the Science Mission Directorate. The Van Allen Probes are the second mission in NASA's Living With a Star program, an initiative managed by Goddard and focused on aspects of the sun-Earth system that directly affect human lives and society.Video:
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August 10, 2016
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https://www.sciencedaily.com/releases/2016/08/160810143703.htm
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With droughts and downpours, climate change feeds Chesapeake Bay algal blooms
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Nitrogen-rich agricultural runoff into the Chesapeake Bay presents an ongoing environmental and economic concern for the bay's massive watershed. Pollution from fertilizer application feeds algal blooms that poison humans and marine life, and devastate fisheries.
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While efforts to restore the bay have been successful during the past several years, a study led by Princeton University researchers shows that weather patterns tied to climate change may nonetheless increase the severity of algal blooms by changing how soil nutrients leach into the watershed.Extreme rainfall cycles caused by increased climate variability flush larger amounts of nitrogen-containing nutrients from fertilizer and other sources into the Susquehanna River, which carries them into the Chesapeake Bay, according to a report in the journal These chemicals feed explosive algae growth that can produce toxins that harm people, fish, wildlife and drinking water. Decaying algae also suck oxygen from the surrounding water, creating a low-oxygen state known as hypoxia that results in "dead zones" that suffocate fish and other species important to the aquatic food chain.The researchers constructed a model that they say provides the most complete picture to date of how nitrogen moves from place to place in the Chesapeake Bay watershed. It connects weather and pollution in places as far away as upstate New York to the water conditions in the bay."The model simulates nitrogen's fate from cradle to grave," said co-author Elena Shevliakova, a visiting research scholar in the Princeton Environmental Institute who works as a physical scientist at the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Lab located on Princeton's Forrestal Campus.First author Minjin Lee, a postdoctoral scholar in Princeton University's Program in Atmospheric and Oceanic Studies, decided to investigate how variations in rainfall -- amplified by climate change -- affected river nitrogen levels after she created simulations of nitrogen flow into the Chesapeake Bay watershed and looked for factors that affect nitrogen run-off."While running the model, I found that there was a lot of year-to-year variability in precipitation, which has implications for how much nitrogen was washed into the river," Lee said. "Even if farmers are using exactly the same amount of fertilizer each year, depending on the weather, more nitrogen can go into the river some years."Lee developed the model during her graduate studies with Peter Jaffe, a Princeton professor of civil and environmental engineering. Lee and Jaffe worked with researchers at GFDL and the U.S. Geological Survey (USGS) to build their model from earlier models of water, geology and biochemistry called Earth Systems Models. These Earth Systems Models had been built over the years by dozens of researchers at GFDL, including Shevliakova and co-authors Sergey Malyshev, a professional specialist in Princeton's Department of Ecology and Evolutionary Biology, and Chris Milly, a research hydrologist at USGS and a research affiliate at GFDL.These models combine physics and biochemistry to simulate how ecologically important chemicals flow through organisms, soil, water and the atmosphere. Some predict how chemicals like nitrogen and phosphorus from fertilizers will move between fertilizers, plants and the soil. Others project how those chemicals will flow through rivers -- and be consumed and excreted by plants and animals along the way -- until reaching the ocean.The decision to look at precipitation variability stemmed from an understanding that rainfall is one of the largest factors that influence the amount of nitrogen fertilizer runoff, Jaffe said."When people talk about climate change, they think about a half-degree average temperature increase," he said. "But it's not the temperature increase that directly affects the nitrogen runoff. With global climate change, you have larger swings between dry and wet conditions. And these swings have a big impact on nitrogen flux."The researchers looked at the effect of wet and dry spells by mixing and matching weather data from the 20th century to emulate possible future climate extremes. They simulated nine climate scenarios based on historical periods of unusually dry or wet years: four dry spells with lengths of one to four years using data from the 1960s; four wet spells of the same length using data from the 1970s; and one year of normal precipitation in 1954. They followed each of the nine wet or dry scenarios with weather from each of the 61 years from 1948 to 2008, creating several hundred total experiments.The researchers found that the amount of rainfall in the years preceding a given year can have as much effect on nitrogen runoff as the weather in that year itself. Although researchers have known that a particularly rainy season can leach more nitrogen out of the soil and lead to algal blooms, the role that unusually dry years play was not expected.Lee's model showed that because nitrogen builds up in the soil during dry years, even an average year following a dry spell could lead to high enough runoff to cause algal blooms. Dry spells of one to three years increase the likelihood of enough nitrogen entering the bay to cause a large dead zone -- a threshold of about 56,000 tons of nitrogen per year -- by 40 to 65 percent.The research is just one example of how climate change's effects run beyond an increase in temperature, said Amilcare Porporato, a Duke University professor of civil and environmental engineering who is familiar with the research but was not involved in the study."It shows how climate change often produces the most dramatic consequences when the alterations involve rainfall and the hydrologic cycle," he said. "Increasing temperatures are only the tip of the iceberg, so to speak.""This highlights the need for different management strategies," Shevliakova said. Algal blooms can be prevented by decreases in fertilizer use, but using the same low amount of fertilizer every year could have subtle and varying impacts on algal blooms in coastal waters depending on the amount of precipitation during the past several years.The study's authors envision adaptive watershed-management plans where models are combined with data from recent years' weather and predictions for the upcoming year to understand where and how much fertilizer can be applied in the watershed before it threatens algal blooms."It's a balance," Jaffe said. "If you tell the farmer to put in less nitrogen, maybe your crop yield goes down, but then the oyster yield goes up in the bay."Such an environmental strategy would require understanding other sources of nitrogen -- such as automobile pollution and sewage -- and other nutrients, such as phosphorus, that contribute to algal blooms. Lee's model already accounts for all sources of nitrogen, and was developed in a manner that allows it to be expanded to a global-scale model that includes other chemicals and land-use patterns.The article, "Climate variability and extremes, interacting with nitrogen storage, amplify eutrophication risk," was published July 16, 2016, in
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| 2,016 |
August 9, 2016
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https://www.sciencedaily.com/releases/2016/08/160809145123.htm
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1967 solar storm nearly took US to brink of war
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A solar storm that jammed radar and radio communications at the height of the Cold War could have led to a disastrous military conflict if not for the U.S. Air Force's budding efforts to monitor the sun's activity, a new study finds.
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On May 23, 1967, the Air Force prepared aircraft for war, thinking the nation's surveillance radars in polar regions were being jammed by the Soviet Union. Just in time, military space weather forecasters conveyed information about the solar storm's potential to disrupt radar and radio communications. The planes remained on the ground and the U.S. avoided a potential nuclear weapon exchange with the Soviet Union, according to the new research.Retired U.S. Air Force officers involved in forecasting and analyzing the storm collectively describe the event publicly for the first time in a new paper accepted for publication in The storm's potential impact on society was largely unknown until these individuals came together to share their stories, said Delores Knipp, a space physicist at the University of Colorado in Boulder and lead author of the new study. Knipp will give a presentation about the event on August 10, 2016 at the High Altitude Observatory at the National Center for Atmospheric Research in Boulder, Colorado.The storm is a classic example of how geoscience and space research are essential to U.S. national security, she said."Had it not been for the fact that we had invested very early on in solar and geomagnetic storm observations and forecasting, the impact [of the storm] likely would have been much greater," Knipp said. "This was a lesson learned in how important it is to be prepared."The U.S. military began monitoring solar activity and space weather -- disturbances in Earth's magnetic field and upper atmosphere -- in the late 1950s. In the 1960s, a new branch of the Air Force's Air Weather Service (AWS) monitored the sun routinely for solar flares -- brief intense eruptions of radiation from the sun's atmosphere. Solar flares often lead to electromagnetic disturbances on Earth, known as geomagnetic storms, that can disrupt radio communications and power line transmissions.The AWS employed a network of observers at various locations in the U.S. and abroad who provided regular input to solar forecasters at the North American Aerospace Defense Command (NORAD), a U.S. and Canadian organization that defends and controls airspace above North America. By 1967, several observatories were sending daily information directly to NORAD solar forecasters.On May 18, 1967, an unusually large group of sunspots with intense magnetic fields appeared in one region of the sun. By May 23, observers and forecasters saw the sun was active and likely to produce a major flare. Observatories in New Mexico and Colorado saw a flare visible to the naked eye while a solar radio observatory in Massachusetts reported the sun was emitting unprecedented levels of radio waves.A significant worldwide geomagnetic storm was forecast to occur within 36-48 hours, according to a bulletin from NORAD's Solar Forecast Center in Colorado Springs, Colorado on May 23.As the solar flare event unfolded on May 23, radars at all three Ballistic Missile Early Warning System (BMEWS) sites in the far Northern Hemisphere were disrupted. These radars, designed to detect incoming Soviet missiles, appeared to be jammed. Any attack on these stations -- including jamming their radar capabilities -- was considered an act of war.Retired Colonel Arnold L. Snyder, a solar forecaster at NORAD's Solar Forecast Center, was on duty that day. The tropospheric weather forecaster told him the NORAD Command Post had asked about any solar activity that might be occurring."I specifically recall responding with excitement, 'Yes, half the sun has blown away,' and then related the event details in a calmer, more quantitative way," Snyder said.Along with the information from the Solar Forecast Center, NORAD learned the three BMEWS sites were in sunlight and could receive radio emissions coming from the sun. These facts suggested the radars were being 'jammed' by the sun, not the Soviet Union, Snyder said. As solar radio emissions waned, the 'jamming' also waned, further suggesting the sun was to blame, he said.During most of the 1960s, the Air Force flew continuous alert aircraft laden with nuclear-weapons. But commanders, thinking the BMEWS radars were being jammed by the Russians and unaware of the solar storm underway, put additional forces in a "ready to launch" status, according to the study."This is a grave situation," Knipp said. "But here's where the story turns: things were going horribly wrong, and then something goes commendably right."The Air Force did not launch additional aircraft, and the study authors believe information from the Solar Forecasting Center made it to commanders in time to stop the military action, including a potential deployment of nuclear weapons. Knipp, quoting public documents, noted that information about the solar storm was most likely relayed to the highest levels of government -- possibly even President Johnson.The geomagnetic storm, which began about 40 hours after the solar flare and radio bursts, went on to disrupt U.S. radio communications in almost every conceivable way for almost a week, according to the new study. It was so strong that the Northern Lights, usually only seen in or near the Arctic Circle, were visible as far south as New Mexico.According to Snyder and the study authors, it was the military's correct diagnosis of the solar storm that prevented the event from becoming a disaster. Ultimately, the storm led the military to recognize space weather as an operational concern and build a stronger space weather forecasting system, he said.The public is likely unaware that natural disasters could potentially trick contemporary military forces into thinking they are under attack, said Morris Cohen, an electrical engineer and radio scientist at Georgia Institute of Technology in Atlanta who was not involved in the new study."I thought it was fascinating from a historical perspective," he said of the new study.The May 1967 storm brought about change as a near miss rather than a full-blown catastrophe, according to Cohen."Oftentimes, the way things work is something catastrophic happens and then we say, 'We should do something so it doesn't happen again,'" he said. "But in this case there was just enough preparation done just in time to avert a disastrous result."
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August 9, 2016
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https://www.sciencedaily.com/releases/2016/08/160809095644.htm
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K computer and high-tech weather radar come together to predict sudden torrential rains
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An international team led by Takemasa Miyoshi of the RIKEN Advanced Center for Computational Science (AICS) has used the powerful K computer and advanced radar observational data to accurately predict the occurrence of torrential rains in localized areas.
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Today, supercomputer-based weather predictions are typically done with simulations that use grids spaced at least one kilometer apart, and incorporate new observational data every hour. However, due to the roughness of the calculations, these simulations cannot accurately predict the threat of torrential rains, which can develop within minutes when cumulonimbus clouds suddenly develop. Now, an international team led by Takemasa Miyoshi of the RIKEN Advanced Center for Computational Science (AICS) has used the powerful K computer and advanced radar observational data to accurately predict the occurrence of torrential rains in localized areas.The key to the current work, to be published later this month in the August issue of the Bulletin of the American Meteorological Society, is "big data assimilation" using computational power to synchronize data between large-scale computer simulations and observational data.Using the K computer, the researchers carried out 100 parallel simulations of a convective weather system, using the nonhydrostatic mesoscale model used by the Japan Meteorological Agency, but with 100-meter grid spacing rather than the typical 2-kilometer or 5-kilometer spacing, and assimilated data from a next-generation phased array weather radar, which was launched in the summer of 2012 by the National Institute of Information and Communications Technology (NICT) and Osaka University. With this, they produced a high-resolution three-dimensional distribution map of rain every 30 seconds, 120 times more rapidly than the typical hourly updated systems operated at the world's weather prediction centers today.To test the accuracy of the system, the researchers attempted to model a real case -- a sudden storm that took place on July 13, 2013 in Kyoto, close enough to Osaka that it was caught by the radars at Osaka University. The simulations were run starting at 15:00 Japanese time, and were tested as pure simulations without observational data input as well as with the incorporation of data every 30 seconds, on 100-meter and 1-kilometer grid scales. The simulation alone was unable to replicate the rain, while the incorporation of observational data allowed the computer to represent the actual storm. In particular, the simulation done with 100-meter grids led to a very accurate replication of the storm compared to actual observations.According to Miyoshi, "Supercomputers are becoming more and more powerful, and are allowing us to incorporate ever more advanced data into simulations. Our study shows that in the future, it will be possible to use weather forecasting to predict severe local weather phenomena such as torrential rains, a growing problem which can cause enormous damage and cost lives."
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Weather
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August 3, 2016
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https://www.sciencedaily.com/releases/2016/08/160803111746.htm
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Researchers work to understand causes of search and rescue in the Arctic
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Search and rescue operations in Nunavut have more than doubled over the past decade. In the communities of the vast northern Canadian territory, it's commonly felt that climate change is one factor making hunting riskier in the spring and fall.
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A new study shows a strong link between environmental conditions and search and rescues cases across Nunavut, moving scientists closer to understanding the impact of climate change on Inuit."Hunting and travelling on the land and sea are an essential component of food security and cultural identity for many in Nunavut. The effects of climate change threaten this way of life for the Inuit." says Dylan Clark, a member of the Climate Change Adaptation Research group headed by McGill geography professor Prof. James Ford.To conduct the study, Clark, a Ph.D student used data from Canada's National Search and Rescue Secretariat for search operations in 2013 and 2014 in communities across Nunavut, along with weather records from Environment Canada. He also used gasoline sales in Nunavut communities to identify days when people may have gone out on ATVs, snowmobiles or boats."We wanted to be able to say there were a lot of people out on this particular day and no one needed a search, but very few people were out on another day and the search was needed," Clark says. "Now, what were the weather conditions on each of those days?"See a video at: Clark found that the risks peak around -3 C, confirming what he had been hearing from community members."This study puts us one step closer to understanding climate change impacts on land safety," Clark says. "Hunters may want to take extra precautions when they go out on those days and search and rescue volunteers may want to ensure they're ready for a mission. Now that we know environmental conditions are linked to risk, we will need to look at the bigger picture to understand how social and environmental changes are interacting to impact risk."
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Weather
| 2,016 |
August 2, 2016
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https://www.sciencedaily.com/releases/2016/08/160802112728.htm
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Impact of extreme weather events on striped bass
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Striped bass are known to have favorite summer swimming spots to which they return every year. They are creatures of habit. However, when a hurricane hits, everything can change very quickly. The water level rises rapidly. Runoff floods the river with sediment and chokes off the oxygen. Heavy rains create rushing currents and a sudden drop in water temperature. And the fish leave the area in a hurry. Scientists call it "evacuating" to better conditions.
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Researchers from the University of Maryland Center for Environmental Science wanted to know the impact of severe storms on fish populations that have to make sudden and unexpected trips downstream, away from their preferred habitat, to more hospitable waters. Thanks to global warming, waterways that make up important habitat for fish are likely to experience an increased frequency of such extreme conditions."These events happen naturally, but having them occur more frequently may have a bigger impact on the fish," said the study's lead author Helen Bailey. "If you get more frequent storms during the year, it is possible you could interrupt their breeding and feeding in ways that impact their population."Bailey and Dave Secor tracked 22 striped bass in the Hudson River Estuary (which hosts one of the largest populations of this species) and New York Harbor during the Tropical Storms Irene and Lee in 2011. Occurring about a week apart, the significant weather events caused heavy rainfall, major flooding, and sudden influxes of fresh, cold water into the waterways.The year before, during normal conditions, researchers had tagged the fish that lived there with small electronic transmitters that regularly pinged their every move. After the storms, they were able to compare the data to examine how their behavior was impacted by the extreme storm events."There are very few studies on this because it so hard to sample during these storm events. You can't predict when they will happen and these can be hazardous conditions to work in," said Bailey. "Telemetry data gave us the opportunity to do it."The researchers discovered that when the storms hit, most of the fish rapidly left the Hudson River and New York Harbor, moving south along the coast. A few remained in the harbor and were able to avoid being displaced. Others did a few exploratory trips later back to the harbor to check on conditions over the next few months and eventually returned up the river."It's not unusual for fish to be leaving this area at this time of year," said Bailey. "What was very unusual was that so many of them did it, they went so far south, and they did it so quickly."There were several changes to the behavior that the researchers didn't expect. Most concerning, depending on when the storm events occurred, some of the striped bass that evacuated the areas did not immediately return, adopting new migration behaviors."The responses of fish species to extreme weather events will need to be considered when planning management strategies to ensure efforts are appropriately targeted to maintain key population segments and critical evacuation routes," said Dave Secor, the study's co-author at the University of Maryland Center for Environmental Science's Chesapeake Biological Laboratory.Located where the Patuxent River meets the Chesapeake Bay, the Chesapeake Biological Laboratory is the oldest publicly supported marine laboratory on the East Coast. Founded in 1925, it has long been a national leader in fisheries, environmental chemistry and toxicology, and ecosystem science and restoration ecology with a focus on whole ecosystem management and restoration. From developing successful fisheries management plans and breaking new ground in understanding how chemicals move between the atmosphere, sediments, and water to renowned work on nutrient dynamics and the food web, the lab is developing new scientific approaches to solving environmental management problems that face our world."Coastal evacuations by fish during extreme weather events" by Helen Bailey and David Secor of the University of Maryland Center for Environmental Science's Chesapeake Biological Laboratory, was published online in
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Weather
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July 27, 2016
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https://www.sciencedaily.com/releases/2016/07/160727090604.htm
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Saharan dust: Reliable forecasts for photovoltaic output
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A hazy sky and dirty cars are well-known consequences of Saharan dust carried to Europe by air currents. As part of the "PerduS" project, the German Weather Service (DWD), the Karlsruhe Institute of Technology (KIT) and meteocontrol are currently examining how dust -- as haze in the atmosphere and deposited on solar panels -- affects the output of photovoltaic systems. The aim is to provide a more reliable forecast for the output of photovoltaic systems through a better prediction of the spread of dust.
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When it comes to Saharan dust outbreaks, the photovoltaic output is reduced not only through a significant increase in atmospheric aerosol content by 10 to 20 percent, but also through dust deposition on the photovoltaic modules on subsequent days. These are the findings of preliminary investigations by the project partners. Often the term "blood rain" is used in combination with the soiling of cars by Saharan dust mixing with rain."With Saharan dust outbreaks, atmospheric currents carry dust blown up in the Sahara over very long distances, even as far as Central Europe," Dr. Bernhard Vogel, meteorologist at KIT, explains. "On a long-term average, we're observing this on four days a month in spring and summer in Germany, and in some years on up to nine days a month."According to the Federal Statistical Office, six percent of total gross electricity was generated by photovoltaic systems in Germany in 2015. The installed capacity of all photovoltaic systems is around 39 gigawatts in the whole of Germany, which means that the systems can produce a peak output of more than 30 gigawatts on cloudless days. This corresponds to the output of more than 20 German nuclear power plants. So far, output forecasts cannot yet realistically take into account the effect of Saharan dust, but the project team thinks that this is necessary to ensure grid stability.The Federal Ministry for Economic Affairs and Energy is funding the PerduS research project for four years. The primary objective is to bring together all components in a forecasting process, which are necessary for taking into account Saharan dust outbreaks for the prediction of the photovoltaic output. This involves expanding ICON, the numerical weather forecast model from DWD, with an improved dispersion prediction of desert dust in collaboration with KIT. The ICON-ART modelling system will then be used for future dust outbreaks alongside the commonly used numerical weather prediction. This means that the system will provide information on the sunlight which is reduced by simulated dust distribution. Based on this, the forecast service provider meteocontrol will produce power forecasts, and evaluate the technical and economic benefit of the new forecast system. The expected soiling of photovoltaic systems by the deposited Saharan dust will also be estimated, and how soon the dust will be washed off by rain later on.To expand the ICON modelling system, which has been used at DWD for the daily numerical weather prediction since January 2015, the Institute of Meteorology and Climate Research at KIT developed the ART module (Aerosols and Reactive Trace Gases). It enables the dispersion of particles such as mineral dust and sea salt and their interaction with clouds to be simulated. In the past and also in collaboration with DWD, ICON-ART was used in forecasts for simulating the dispersion of ash particles following volcanic eruptions. KIT's main research objectives in PerduS are to further develop the description of dust emissions in the Saharan source region, and to better describe the interaction between dust particles and atmospheric radiation.What's more, measurements at the solar power storage park at KIT Campus North are carried out to determine the level of soiling of the solar panels by deposited mineral dust and its effect on photovoltaic output. The scientists also use these measurements to record the effect of precipitation in cleaning the solar panels again. To achieve this they use precipitation radar, KIT's measuring tower, instruments for measuring droplet size distribution and the amount of precipitation, and DWD's Aerosol lidar system. The descriptions of the relevant processes derived from these measurements will then be integrated into the ICON-ART modelling system.
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Weather
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July 26, 2016
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https://www.sciencedaily.com/releases/2016/07/160726123630.htm
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Decade-long cooling cycle: Middle atmosphere in sync with ocean
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Water plays a major role for our planet not only in its liquid form at the surface. In the atmosphere too, it considerably affects our lives as well as weather and climate. Clouds and rainfall are one example. Water vapor, the gaseous form of water, also plays a prominent role on Earth. It is the most important greenhouse gas in the atmosphere, without it the Earth would be a frozen planet. For climate variations, water vapor is particularly important in the stratosphere at altitudes between 15 and 50 kilometers. How much of the gas actually reaches the stratosphere mainly depends on the temperature at the transition between the lowest atmospheric layer, the troposphere, and the overlying stratosphere. This boundary layer is called the tropopause.
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Now scientists of the GEOMAR Helmholtz Centre for Ocean Research Kiel, together with a colleague from Bergen (Norway), were able to demonstrate for the first time that natural fluctuations in water temperatures of the Pacific -- which occur on decadal timescales -- are directly related to the temperature of the tropical tropopause. "It has long been thought that human influences already affected the tropopause. However, it seems that natural variability is still the dominating factor," says Dr. Wuke Wang from GEOMAR, lead author of the study just published in the international journal For their study, the researchers used observations for the period 1979-2013 and also climate models. "We were thus able to extend the study period to nearly 150 years. The model allows us to easily look at both human and natural influences and to separate their impacts from each other," explains Prof. Dr. Katja Matthes, climate researcher at GEOMAR and co-author of the study.A well-known climatic phenomenon is the so-called Pacific Decadal Oscillation (PDO). "This natural variation with decadal timescale leads to anomalously high or low water temperatures of the Pacific," explained Dr. Wang. The PDO influences the climate and ecosystems in the Pacific region and also the global mean temperature of the Earth.The model simulations show that the fluctuations in water temperatures also affect the wind systems over the tropical and subtropical Pacific. This in turn also alters the air transport between the lower and upper layers of the troposphere, ultimately regulating the temperatures at the boundary to the stratosphere. "We were now able to demonstrate these relationships for the first time," said Dr. Wang.Thus, the current study contradicts earlier hypotheses about the temperature variability of the tropical tropopause. As early as in the late 20th century, scientists had seen a cooling trend there which began in the 1970s. They traced this observation back to anthropogenic causes, in particular the increase in greenhouse gases. "However, this assumption was based on a rather patchy data base and simplified climate models. Our study shows that the cooling of the tropical tropopause does not have to be a one-way street but could also be part of a natural fluctuation which extends over several decades," Professor Matthes emphasized.This knowledge is also of paramount importance for the general climate research. The temperature of the tropopause decides on the input of water vapor into the stratosphere: The higher the water vapor content in the stratosphere, the higher the increase in surface temperatures. Anthropogenic climate change also has an effect on the temperature of the tropopause, and this effect could become more evident in the coming decades. "Only if we can clearly distinguish natural variability from anthropogenic influences, we can make reliable forecasts for the future development of our climate," Prof. Matthes summarizes.
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Weather
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July 25, 2016
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https://www.sciencedaily.com/releases/2016/07/160725224032.htm
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Distant volcanic eruptions foster saguaro cacti baby booms
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One hundred and thirty years ago, the volcano Krakatoa erupted in what is now Indonesia, unleashing a cataclysm locally and years of cool temperatures and rain globally. On the far side of the world, a bumper crop of saguaro cacti were getting their start in life in Arizona's Sonoran Desert. Many of the large exemplars of the famous cacti standing spiny and tall with arms akimbo in the Southwest today started their lives in the shadow of the 1883 eruption.
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Biogeographer Taly Drezner believes that distant volcanic paroxysms and the emergence of bountiful saguaro age-mate cohorts are connected. Volcanic climate perturbations that delivered disastrously cold and stormy weather to much of the Northern Hemisphere generated a combination of conditions in the Sonoran Desert that were just right for the delicate young cacti. Drezner will present her research on the first known example of regional population effects on a species from volcanic eruptions in distant parts of the world on 9 August 2016 at the 101st Annual Meeting of the Ecological Society of America, gathering this year in Fort Lauderdale, Florida."The saguaro is key to the survival of many species. Almost every animal in the Sonoran uses them in some way, as a nest site, or food, or a cool refuge," said Drezner, a professor at York University in Ontario, who studies among other things, how heat and aridity shape the community of life in the desert. Temperatures can easily exceed 40 C (104 F) every day for weeks in summer, when saguaro seedlings have just germinated.A keystone species of the Sonoran ecosystem and charismatic cultural emblem of the arid southwestern United States, the saguaro (In the year after Krakatoa, summer temperatures in the Northern Hemisphere fell 1.2?C below average. The eruption violently disgorged tons of ash and sulfur dioxide gas into the stratosphere. Dust particles and sulfuric acid droplets rode winds through the upper atmosphere, conspiring in a haze that reflected sunshine and lowered global temperatures. Though not as disruptive as the "year without a summer" that followed the eruption of Mount Tambora in 1815, Krakatoa's influence was seen and felt around the globe in vivid sunsets and stormy weather. Southern California experienced a "water year" of record rainfall. Sulfate aerosols in particular can hang out in the atmosphere for years, and Krakatoa released an unusual abundance of sulfur. Typical temperature and weather patterns did not recover for years. For the saguaro, the perturbations appear to have amounted to a collection of "just right" conditions for new growth."I started noticing that these saguaro age cohorts followed notable volcanic eruptions," said Drezner. "I knew that volcanoes drive milder summers and winters, and typically more rainfall for an extended period -- two to three years after the event, which is a perfect window of time for the saguaro to get established and have a chance to survive."To investigate her hunch, Drezner went to Kofa National Wildlife Refuge near Yuma, Arizona, where limited water pushes the physiological limits of the saguaro, to sample the age structure of the local cacti. Rainfall at Kofa is a third of other locations in the Sonoran. Cacti do not have rings, like trees, that make age simple to gauge. Drezner estimated the ages of 250 cacti based on meticulous calculations of local growth rates using a model she pioneered. She added data from 30 locations in the Northern Sonoran Desert and compared the generational cohorts of the cacti to climate datasets for the region and the annual Weighted Historical Dust Veil Index, an indicator of volcanism.Saguaro boom years tracked the peaks in the dust index, particularly in the marginal environment at Kofa. High volcanic dust levels also correlated with warmer, wetter, local winters, and more rain in late spring."The saguaro are protected because they are a beloved symbol and icon of the desert," Drezner said. They are not currently threatened, but the unpredictable nature of their reproduction makes some conservators nervous about how the giants will respond to a changing climate. "That a volcano elsewhere on the continent, or even the other side of the world, can so profoundly influence a local population underscores interconnectedness of ecosystems and our global climate."
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July 21, 2016
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https://www.sciencedaily.com/releases/2016/07/160721151500.htm
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Trees' surprising role in the boreal water cycle quantified
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Approximately 25 to 50 percent of a living tree is made up of water, depending on the species and time of year. The water stored in trees has previously been considered just a minor part of the water cycle, but a new study by University of Alaska Fairbanks scientists shows otherwise.
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Research published this week in The results are critical for understanding boreal forest hydrology and ecology, including soil moisture, the availability of freshwater, tree health and the ways trees influence regional weather, particularly thunderstorms. All of these factors are important for understanding the frequency and severity of wildland fires.Like a straw, trees draw water up from the soil and eventually release it into the atmosphere through leaves or needles. The scientists measured the water content in both deciduous and evergreen trees in several locations at different times of the year.They found that deciduous trees took up a surprisingly large amount of water in the period between snowmelt and leaf-out. These trees absorbed 21 to 25 percent of the available snowmelt water -- to the point of being completely saturated. For the boreal forest of Alaska and Western Canada, this equates to about 17-20 billion cubic meters of water per year. That is roughly equivalent to 8 million Olympic-sized swimming pools or 8-10 percent of the Yukon River's annual discharge.The study also quantified transpiration -- the water that trees release to the atmosphere. The researchers found that deciduous trees transpired 2 to 12 percent of the absorbed snowmelt water immediately after leaf-out. This concentrated period of transpiration has the potential to create more favorable conditions for atmospheric convection and thunderstorms, which start many of the wildfires in the sparsely populated boreal forest region.Calculating the amount of water stored by deciduous trees is important. The area occupied by deciduous trees in the boreal forest is expected to increase 1 to 15 percent by the end of this century, and the absorption of snowmelt could also then increase.This is the first study to show that deciduous tree water uptake of snowmelt water represents a large but overlooked aspect of the water balance in boreal watersheds. Tree water dynamics impact many processes. Quantifying tree water storage is important for understanding hydrology, tree response to drought and the related factors of tree water use, soil moisture and climate.
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July 19, 2016
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https://www.sciencedaily.com/releases/2016/07/160719144737.htm
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2016 climate trends continue to break records
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Two key climate change indicators -- global surface temperatures and Arctic sea ice extent -- have broken numerous records through the first half of 2016, according to NASA analyses of ground-based observations and satellite data.
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Each of the first six months of 2016 set a record as the warmest respective month globally in the modern temperature record, which dates to 1880, according to scientists at NASA's Goddard Institute for Space Studies (GISS) in New York. The six-month period from January to June was also the planet's warmest half-year on record, with an average temperature 1.3 degrees Celsius (2.4 degrees Fahrenheit) warmer than the late nineteenth century.Five of the first six months of 2016 also set records for the smallest respective monthly Arctic sea ice extent since consistent satellite records began in 1979, according to analyses developed by scientists at NASA's Goddard Space Flight Center, in Greenbelt, Maryland. The one exception, March, recorded the second smallest extent for that month.While these two key climate indicators have broken records in 2016, NASA scientists said it is more significant that global temperature and Arctic sea ice are continuing their decades-long trends of change. Both trends are ultimately driven by rising concentrations of heat-trapping carbon dioxide and other greenhouse gases in the atmosphere.The extent of Arctic sea ice at the peak of the summer melt season now typically covers 40 percent less area than it did in the late 1970s and early 1980s. Arctic sea ice extent in September, the seasonal low point in the annual cycle, has been declining at a rate of 13.4 percent per decade."While the El Niño event in the tropical Pacific this winter gave a boost to global temperatures from October onwards, it is the underlying trend which is producing these record numbers," GISS Director Gavin Schmidt said.Previous El Niño events have driven temperatures to what were then record levels, such as in 1998. But in 2016, even as the effects of the recent El Niño taper off, global temperatures have risen well beyond those of 18 years ago because of the overall warming that has taken place in that time.The global trend in rising temperatures is outpaced by the regional warming in the Arctic, said Walt Meier, a sea ice scientist at NASA Goddard."It has been a record year so far for global temperatures, but the record high temperatures in the Arctic over the past six months have been even more extreme," Meier said. "This warmth as well as unusual weather patterns have led to the record low sea ice extents so far this year."NASA tracks temperature and sea ice as part of its effort to understand the Earth as a system and to understand how Earth is changing. In addition to maintaining 19 Earth-observing space missions, NASA also sends researchers around the globe to investigate different facets of the planet at closer range. Right now, NASA researchers are working across the Arctic to better understand both the processes driving increased sea ice melt and the impacts of rising temperatures on Arctic ecosystems.NASA's long-running Operation IceBridge campaign last week began a series of airborne measurements of melt ponds on the surface of the Arctic sea ice cap. Melt ponds are shallow pools of water that form as ice melts. Their darker surface can absorb more sunlight and accelerate the melting process. IceBridge is flying out of Barrow, Alaska, during sea ice melt season to capture melt pond observations at a scale never before achieved. Recent studies have found that the formation of melt ponds early in the summer is a good predictor of the yearly minimum sea ice extent in September."No one has ever, from a remote sensing standpoint, mapped the large-scale depth of melt ponds on sea ice," said Nathan Kurtz, IceBridge's project scientist and a sea ice researcher at NASA Goddard. "The information we'll collect is going to show how much water is retained in melt ponds and what kind of topography is needed on the sea ice to constrain them, which will help improve melt pond models."Operation IceBridge is a NASA airborne mission that has been flying multiple campaigns at both poles each year since 2009, with a goal of maintaining critical continuity of observations of sea ice and the ice sheets of Greenland and Antarctica.At the same time, NASA researchers began in earnest this year a nearly decade-long, multi-faceted field study of Arctic ecosystems in Alaska and Canada. The Arctic-Boreal Vulnerability Experiment (ABoVE) will study how forests, permafrost and other ecosystems are responding to rising temperatures in the Arctic, where climate change is unfolding faster than anywhere else on the planet.ABoVE consists of dozens individual experiments that over years will study the region's changing forests, the cycle of carbon movement between the atmosphere and land, thawing permafrost, the relationship between fire and climate change, and more.
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July 19, 2016
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https://www.sciencedaily.com/releases/2016/07/160719123906.htm
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NASA science flights target melting Arctic Sea ice
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This summer, with sea ice across the Arctic Ocean shrinking to below-average levels, a NASA airborne survey of polar ice just completed its first flights. Its target: aquamarine pools of melt water on the ice surface that may be accelerating the overall sea ice retreat.
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NASA's Operation IceBridge completed the first research flight of its new 2016 Arctic summer campaign on July 13. The science flights, which continue through July 25, are collecting data on sea ice in a year following a record-warm winter in the Arctic.The summer flights will map the extent, frequency and depth of melt ponds, the pools of melt water that form on sea ice during spring and summer. Recent studies have found that the formation of melt ponds early in the summer is a good predictor of the sea ice yearly minimum extent in September: if there are more ponds on the ice earlier in the melt season, they reduce the ability of sea ice to reflect solar radiation, which leads to more melt."Although there have been previous airborne campaigns in the Arctic, no one has ever mapped the large-scale depth of melt ponds on sea ice using remote sensing data," said Nathan Kurtz, IceBridge's project scientist and a sea ice researcher at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "The information we'll collect is going to show how much water is retained in melt ponds and what kind of topography is needed on the sea ice to constrain them, which will help improve melt pond models."This short flight campaign is operating from Barrow, Alaska. The flights are low at an altitude of 1500 feet (450 meters) aboard an HU-25C Guardian Falcon aircraft from NASA's Langley Research Center in Hampton, Virginia. The plane carries three instruments that measure changes in the ice elevation and surface temperatures and create color maps of sea ice.Operation IceBridge provides connectivity between the measurements of polar ice between two NASA satellite campaigns: the Ice, Cloud and land Elevation Satellite, or ICESat, which operated from 2003 to 2009, and its successor, ICESat-2, scheduled to launch by 2018. The Barrow campaign will give a glimpse into what ICESat-2 will be able to observe in the Arctic in the summertime, since the laser altimeter IceBridge carries is similar to the one that will be aboard ICESat-2.Kurtz expects that flying in the summer will allow his team to find areas of sea ice not covered by snow, which will let them take direct measurements of the freeboard, the fraction of sea ice that floats above the waterline. This measurement would improve studies of sea ice thickness in the Arctic.Flights will be shorter than the usual IceBridge Arctic flights, due to the Falcon's smaller fuel capacity compared to the P-3 aircraft that IceBridge normally uses in the Arctic. In total, IceBridge scientists are expecting to carry out five 4-hour-long flights, each one covering 1000 nautical miles (1150 miles) and focusing on the Beaufort and Chukchi seas north of Russia, Alaska and Canada.."The advantage of being based in Barrow is that we'll be starting the flights right from the water's edge," Kurtz said.For its annual Arctic and Antarctic campaigns, IceBridge flights follow pre-established lines selected by the scientific community. But in Barrow, due to weather uncertainty, the mission will pursue targets of opportunity."The day before the flight we'll be looking at weather imagery and models, and I'll try to plan a flight line that basically gets into any hole in the clouds there is, rather than following a specific path," Kurtz said.NASA's Wallops Flight Facility in Virginia provided the laser altimeter and the infrared camera that are being used during this summer campaign. IceBridge's Digital Mapping System came from NASA's Ames Research Center at Moffett Field, California.
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July 19, 2016
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https://www.sciencedaily.com/releases/2016/07/160719111311.htm
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What hibernating toads tell us about climate
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The ability to predict when toads come out of hibernation in southern Canada could provide valuable insights into the future effects of climate change on a range of animals and plants.
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McGill University professor David M. Green of the Redpath Museum and his students have been studying Fowler's Toads on the shore of Lake Erie at Long Point, Ontario, for over 24 consecutive years. Green's focus? To use weather records to predict the springtime emergence of toads from their annual eight-month hibernation -- and, by doing so, determine if a warming climate is changing the toads' behaviour.Green found that the toads' timing can be predicted based on environmental conditions well before the bumpy-skinned amphibians actually wake up. ""The toads are buried up to a meter deep in the sand. What drives them to come up is when the sand below them becomes colder than the sand above," explains Green. "Year after year, on average, this has been getting earlier and earlier."The model Green has developed could have broader applications, he says. . On the grander scale, if this approach applies to other animals and plants, too, we could generate some powerful information about what is to come as the climate warms.The long-running project stemmed, somewhat inadvertently, from Green's PhD research into the interbreeding between Fowler's and American Toads. When he became a McGill professor, Green continued to study the toads' behaviour, "Because I needed to be at the scene for the start of the toads' breeding season, I began to note when the toads came out of hibernation," he says. "While I didn't set out to study climate change 25 years ago, the data I collected turned out to be far more valuable and interesting then I could have imagined!"During the nearly quarter-century that Green has been studying toads in the field at night, he's encountered his share of hardships. Once, his car got stuck in a sand drift, forcing him to "walk six kilometres with leaky boots with only a failing headlamp to get home,'" he recalls. But the painstaking observations have made possible the model that now enables him to predict the toads' springtime emergence.And the work continues. To test his predictions and make them more precise, Green now has probes in the dunes at Long Point that are recording temperatures underground every 30 minutes. "What the temperature does and what the toads do should match," Green says. "We can also apply this information to investigate when other organisms living on, and in, the dunes wake up in spring."This work was supported by NSERC Canada, the Canadian Wildlife Service, World Wildlife Fund Canada, the Ontario Ministry of Natural Resources and Forestry, Wildlife Preservation Canada, and the Canadian Wildlife Federation.
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July 19, 2016
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https://www.sciencedaily.com/releases/2016/07/160719111123.htm
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Mountain pine beetles infest and ravage thousands of acres of forest lands, Landsat satellites show
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In western North America, mountain pine beetles infest and ravage thousands of acres of forest lands. Landsat satellites bear witness to the onslaught in a way that neither humans nor most other satellites can.
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Since 1972, the U.S. Geological Survey's Landsat satellites have been the watchman that never sleeps with spectral bands capturing the subtle turning of green mountainsides into dying forests. From the ground, the extent of forest land damage is simply too large for field observers to quantify. But 438 miles above the Earth, Landsat satellites pass over every forest in the country dozens of times a year -- every year -- creating a historical archive of clear, composite images that tells the hidden stories of life and death in our nation's forests.Such was the vision of Secretary of the Interior Stewart Udall 50 years ago when he boldly called for Earth observations from space. What the U.S. Geological Survey has accumulated now are vast and continuous long-term records from Landsat that have become critical tools for agencies such as the U.S. Forest Service (Forest Service), which reports the status and health of our nation's forest resources.Although Forest Service field crews can sample plots to characterize forest types, the species and age of trees, even soil types, the lands are so vast that in the West, field crews visit only a small fraction of the nation's forests each year. Landsat data increase the ability and frequency of the Forest Service to make these characterizations.Through continuous monitoring, Landsat satellites can produce a series of images over time that reveal subtle changes in near real time. Such monitoring is not as crucial in cases of timber harvesting or wildfire as the impact on forests is easily identified in those situations. Pine forests under siege by beetles, however, can die a slow death. Forest Service personnel indicate that noticing such trends can be difficult, depending on whether the trees under assault are just a few or number in the thousands. Although aerial photography and field observations might find some of the tree damage, the large-scale revelations really happen only because of Landsat's ability to monitor forests year after year.In addition to longevity and consistency, Landsat data are particularly valuable since the 2008 USGS decision allowing users free access to archived satellite data. Free access has emboldened the evolution of time-series images, giving forest managers a key economical asset in discerning where outbreaks are happening as they occur. Pine beetle outbreak knowledge in real time enables forest managers to make more informed decisions on when to go in and break up stands of trees affected by beetles, thus minimizing the potential fire threat pine beetle damage could pose.In the larger picture, knowing when and where forests are changing, and what is causing that change, are important in understanding how forests interact with the atmosphere given climate change. The pine beetle is a good example of understanding forest and atmosphere interaction. Researchers can use forest inventory data to study how longer growing seasons and less harsh winters affect pine beetles. As warmer weather boosts pine beetle populations and broadens their range, scientists are trying to discern whether the killing cold of winter still acts as a strong deterrent against the forest pests, or if rising temperatures and drought stress trees to the point of becoming defenseless against pine beetles.Although questions about the impact of pine beetle infestation still remain, with Landsat data, answers are becoming clearer every day. When it comes to the future of forest health in the United States, USGS scientists understand the invaluable contribution Landsat can make, now and for years to come.
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July 15, 2016
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https://www.sciencedaily.com/releases/2016/07/160715171303.htm
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Ptarmigan in Colorado have varied reproduction, not likely linked to warming trends
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Animals that live at high elevations are often assumed to be at risk for extinction as habitats warm and change. But a new study led by Colorado State University researchers found that ptarmigan, which live in cold ecosystems, are not strongly affected by fluctuations in seasonal weather at two populations studied in Colorado.
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The results, published July 15 in the journal Ptarmigan are grouse that live in cold ecosystems, such as alpine and tundra habitats, said Greg Wann, Ph.D. candidate in CSU's Graduate Degree Program in Ecology and a member of the Natural Resource Ecology Laboratory.The birds are well-known for changing colors seasonally. In late spring and summer, ptarmigan are brown, and in the fall, they molt into a white plumage to match the surrounding snow. The white-tailed ptarmigan is the smallest species of this type of grouse and is endemic to North America. It is the only ptarmigan that exists in Colorado.Wann and study co-authors, including CSU Associate Professor Cameron Aldridge, analyzed 45 years of reproductive data for two Colorado populations of white-tailed ptarmigan. The team did not track seasonal temperatures, but noted warming at study sites during the spring and summer, based on data from Niwot Ridge Long Term Ecological Research.Among the findings: ptarmigan annual reproduction did not change at Mt. Evans, which was one of the two sites studied. It declined significantly at the other site, Rocky Mountain National Park."We can't fully explain this decline, but we did not find any strong indications it was due to recent warming," Wann said."Climate did affect when ptarmigan bred, and warmer spring temperatures have led to ptarmigan nesting earlier than they did at the beginning of the study in the 1960s. We don't know if earlier breeding will be a good or bad thing for ptarmigan in the future, but our continued research will help address some of these questions," he added.Aldridge, who is also a scientist with the U.S. Geological Survey, said researchers were surprised that weather did not explain variation in reproductive rates of white-tailed ptarmigan."Ptarmigan can only raise one brood in a season, and the breeding period in the alpine is so short," he explained. "In addition, reproductive rates in many other grouse species are strongly linked to weather. Other factors, like variation in predators or changes in habitat quality due to drying habitats or loss of alpine willow, must be at least as important, if not more important," he said. "We are continuing to investigate those mechanisms at our long-term study sites."Study authors said predators might be more abundant in the alpine during years with less snow cover, or prolonged hot summers may reduce the abundance of plants that ptarmigan rely on for food. The team is currently looking at these other factors through a study by tracking individual birds to measure reproductive rates and the associated habitat quality and predator abundance impacts on the number of young produced.While the study findings appear to downplay the effects of climate change, Wann said it is something that should still be of concern to the public."Climate change is a very big challenge wildlife populations are currently facing and will continue to face over coming decades," he said. "Species that exist on mountaintops may be particularly vulnerable because they are adapted to cold, and, as temperatures increase, they cannot move to cooler environments at higher elevations. Fortunately, the ptarmigan populations we studied appear to be handling the warming summers, at least given the warming that has happened so far. As warming in alpine habitats increases and advance snowmelt even further in the coming years, we hope ptarmigan in Colorado will continue to cope with these changing environments."
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July 14, 2016
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https://www.sciencedaily.com/releases/2016/07/160714135127.htm
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Climate experts help communities cope with impact of the Indian Monsoon
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Work by University of Exeter experts to predict the weather in India could help millions of people prepare for the devastating effects of the country's summer monsoons.
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Climatologists from the University of Exeter have identified a location in central India where they can predict excess monsoon rainfall or drought, which have an enormous impact on the national and global economy.The new study, which concentrates on a region at Central North East India, could allow government and policymakers to make more informed decisions which will give better protection to communities, farmers and businesses. It will enable them to make policy which will mitigate the impact of extreme and unusual weather.By comparing the results of mathematical models with human observations, they have proved it is possible to provide an improved forecast of the Indian Summer Monsoon in Central North East India.The Indian Summer Monsoon has a major impact on agriculture, and therefore the economy, in India, and is responsible for 80 percent of the country's annual rainfall. Farmers rely on this seasonal rain to grow essential crops. Flooding also threatens life. A strong monsoon in 2005 killed more than 1,000 people.Having more accurate forecasts means farmers can choose the crops and plans which are likely to be most successful. It can also help farmers and policymakers plan how to store the excess water.The Indian Summer Monsoon is influenced by the El Niño Southern Oscillation, which causes extreme weather in different parts of the world.The ENSO is mainly caused by fluctuations in sea surface temperature around central to east tropical Pacific Ocean. There are two opposite phases, El Niño and La Niña. During La Niña, that sea surface temperature in the Pacific Ocean is colder, for El Niño, the temperature is warmer. During El Niño there is usually less monsoon rainfall and for La Niña there is more rainfall.Dr Indrani Roy, Dr Renata Tedeschi and Professor Matthew Collins from the College of Engineering, Mathematics and Physical Sciences studied 23 different mathematical models designed to predict information about the climate. They compared them with human observations about the climate and found that models are able to make accurate predictions about the monsoon rain in Central North East India.The team found that data from tropical Pacific Ocean could help them predict the behaviour of the Summer Monsoon in Central North East India. The models did not allow the team to make the same predictions for other regions in India.Dr Roy, the lead author of the study, said: "India is one of the most populated countries in the world, and the monsoon rains have not only a significant impact on the national but also the global economy."Our findings will improve prediction skills which will contribute to better business performance, economic prosperity and wealth creation. It can directly affect the ability of the sub-continent to anticipate and adapt to changes."ENSO Teleconnections to the Indian Summer Monsoon in Observations and Models by Indrani Roy, Renata Tedeschi and Matthew Collins is published in the
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July 12, 2016
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https://www.sciencedaily.com/releases/2016/07/160712173318.htm
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El Niño played a key role in Pacific marine heatwave, as did potentially climate change
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The Northeast Pacific's largest marine heatwave on record was at least in part caused by El Niño climate patterns. And unusually warm water events in that ocean could potentially become more frequent with rising levels of greenhouse gases.
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That's the findings of a new study by researchers from Georgia Institute of Technology and the National Oceanic and Atmospheric Administration. They linked the 2014-2015 marine heatwave -- often referred to as the "warm blob" -- to weather patterns that started in late 2013. The heatwave caused marine animals to stray far outside of their normal habitats, disrupting ecosystems and leading to massive die-offs of seabirds, whales and sea lions.The study, which was published July 11 in journal "We had two and a half years of consistent warming, which translated to a record harmful algal bloom in 2015 and prolonged stress on the ecosystem," said Emanuele Di Lorenzo, a professor in Georgia Tech's School of Earth and Atmospheric Sciences. "What we do in the study is ask whether this type of activity is going to become more frequent with greenhouse gases rising."The researchers traced the origin of the marine heat wave to a few months during late 2013 and early 2014, when a ridge of high pressure led to much weaker winds that normally bring cold Artic air over the North Pacific. That allowed ocean temperatures to rise a few degrees above average.Then, in mid-2014 the tropical weather pattern El Niño intensified the warming throughout the Pacific. The warm temperatures lingered through the end of the year, and by 2015 the region of warm water had expanded to the West Coast, where algal blooms closed fisheries for clams and Dungeness crab."The bottom line is that El Niño had a hand in this even though we're talking about very long-distance influences," said Nate Mantua, a research scientist at NOAA Fisheries' Southwest Fisheries Science Center and a coauthor of the study.The researchers used climate model simulations to show the connection between increasing greenhouse gas concentrations and the impact on the ocean water temperatures. The study found that these extreme weather events could become more frequent and pronounced as the climate warms."This multi-year event caused extensive impacts on marine life," Di Lorenzo said. "For example, some salmon populations have life cycles of three years, so the marine heatwave has brought a poor feeding, growth and survival environment in the ocean for multiple generations. Events like this contribute to reducing species diversity."And the effects of the "warm blob" could linger."Some of these effects are still ongoing and not fully understood because of the prolonged character of the ocean heatwave," Di Lorenzo said. "Whether these multi-year climate extremes will become more frequent under greenhouse forcing is a key question for scientists, resource managers and society."
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July 11, 2016
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https://www.sciencedaily.com/releases/2016/07/160711151319.htm
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Scientists find evidence for climate change in satellite cloud record
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Scientists have found that changes in cloud patterns during the last three decades match those predicted by climate model simulations. These cloud changes are likely to have had a warming effect on the planet.
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Records of cloudiness from satellites originally designed to monitor weather are plagued by erroneous variability related to changes in satellite orbit, instrument calibration and other factors, so the team used a new technique to remove the variability from the records. The corrected satellite records exhibited large-scale patterns of cloud change between the 1980s and 2000s that are consistent with climate model predictions, including poleward retreat of mid-latitude storm tracks, expansion of subtropical dry zones and increasing height of the highest cloud tops.The research from Lawrence Livermore National Laboratory, Scripps Institution of Oceanography, University of California, Riverside and Colorado State University appears in the July 11 edition of the journal, "What this paper brings to the table is the first credible demonstration that the cloud changes we expect from climate models and theory are currently happening," said study lead author Joel Norris, a climate researcher at Scripps.Clouds substantially impact Earth's energy budget by reflecting solar radiation back to space (the albedo effect) and by restricting emission of thermal radiation to space. Most of the uncertainty in how much the planet will warm in response to greenhouse gas emissions is due to uncertainty in how clouds will respond and impact Earth's energy budget."After the spurious trends were removed, we saw consistent responses among several independent datasets and with model simulations," said Mark Zelinka, an LLNL scientist and co-author of the paper. "That is a nice confirmation of the models' predictions, at least for the types of cloud changes that models agree on."The authors also were able to assess the causes of the observed cloud trends using a variety of climate model simulations with and without influences of humans, volcanoes and other factors."If models are correct, the observed cloud trends are very unlikely to have been caused by natural climate variability," said Stephen Klein, another LLNL scientist involved in the research. "Rather, we found that increasing greenhouse gas concentrations and a recovery from volcanic radiative cooling are the primary causes in these decades."The scientists expect the cloud trends to continue in the future as the planet continues to warm due to increasing greenhouse gas concentrations.The research is funded by the National Oceanic and Atmospheric Administration, the Department of Energy Office of Science and NASA.
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| 2,016 |
July 11, 2016
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https://www.sciencedaily.com/releases/2016/07/160711121339.htm
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Subtropical Cornwall climate could mean exotic new crops
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The subtropical weather in Cornwall means new exotic crops such as quinoa and Japanese persimmon are now more likely to succeed, according to a new technique developed by University of Exeter experts to monitor the climate.
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Parts of Cornwall have become subtropical since 2000 and this could create opportunities to grow new, unusual plants. Sunflowers, maize, grapevines and tea are already grown in the Duchy.Researchers from the Environment and Sustainability Institute in Penryn, Cornwall, have developed new techniques for modelling local microclimates. The models capture the effects of terrain, sea temperatures, altitude and soil properties to predict local temperatures, which can differ greatly from those measured at weather stations.Using these models, they have been able to identify particularly mild parts of the landscape that would be most suitable for growing unusual crops associated with warmer climates. Sheltered coastal valleys are often buffered from the coldest temperatures by the more stable sea temperatures, and south-facing slopes are often up to 15 degrees warmer than the surrounding landscape.The model shows that the amount by which temperatures have increased over the last 40 years has varied across the county, as Cornwall has become sunnier as well as warmer, but some locations have benefited from this more than others.Dr Ilya Maclean, a Senior Lecturer in Natural Environment who lead the research, said: "While sub-tropical conditions may create opportunities to grow exotic crops, the lower frequency of frosts is also making Cornwall more susceptible to invasive species. As the temperatures continue to warm, we need to ensure we manage the risks carefully as well as capitalising on the opportunities. This will require scientists to continue to work hand-in-hand with the horticultural sector."The techniques build on those first developed by geographer Glenn Thomas Trewartha, of Cornish-American descent, who in 1966 developed the world famous classification system for grouping climates into polar, boreal, temperate, subtropical and tropical.Using this system, regions in which temperatures are 10ºC or greater for 4-7 months of the year are considered temperate, and those with temperatures of 10ºC or greater for more than 7 months of the year are considered subtropical. At that time the system was developed Cornwall lay firmly in the temperate zone.Climate change impacts and adaptive strategies: lessons from the grapevine is published in the journal
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July 7, 2016
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https://www.sciencedaily.com/releases/2016/07/160707215032.htm
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100s of deaths in 2 cities in 2003 heatwave due to human-made climate change
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Scientists have specified how many deaths can be attributed to human-made climate change during an extreme heatwave in two European cities in 2003. They calculate that in Paris, the hottest city in Europe during the heatwave in summer 2003, 506 out of 735 summer deaths recorded in the French capital were due to a heatwave made worse by human-made climate change. The impact of climate change was less severe in London, with an additional 64 deaths out of a total of 315 heat-related deaths, says the paper published in the scientific journal,
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The findings were generated by putting the results of climate model simulations of the 2003 heatwave into a health impact assessment of death rates. Using computer time donated by thousands of volunteers from the weather@home project, the researchers ran many thousands of high-resolution regional climate model simulations. They found that human-induced climate change increased the risk of heat-related deaths in central Paris by around 70% and by 20% in London.The paper says the mortality rate attributed to human-made climate change in both these cities is notably high, but they are just two of a large number of cities that were affected by the heatwave that year. It suggests that the resulting total number of deaths across Europe due to climate change is likely to be substantially higher.The paper looks at the three months June to August. It warns that no heatwave on record has ever had such a widespread effect on human health, as experienced during those months of 2003. Previous studies have attributed changes in heatwave frequency and severity to human-caused climate change, or demonstrated the effect of extreme heat on human mortality. This paper is the first to attribute the number of premature deaths to climate change during extreme heat waves.Lead author Dr Daniel Mitchell, from the Environmental Change Institute at the University of Oxford, comments: 'It is often difficult to understand the implications of a planet that is one degree warmer than preindustrial levels in the global average, but we are now at the stage where we can identify the cost to our health of human-made global warming. This research reveals that in two cities alone hundreds of deaths can be attributed to much higher temperatures resulting from human-induced climate change.'Co-author Dr Chris Huntingford, of the Centre for Ecology and Hydrology, says: 'Traditionally, climate research has linked increasing levels of greenhouses gases simply to trends in weather, such as generally higher day-to-day temperatures. However, linking the impact of burning of fossil fuels right through to health implications enables much better planning to prepare for any further climatic changes.'By starkly showing we can measure the toll in human lives that climate change is already taking through worsening extreme heat, this study shines a spotlight on our responsibilities as a society for limiting further damage,' adds co-author Dr Peter Frumhoff of the Union of Concerned Scientists, Cambridge, USA.The paper concludes that with climate change projected to increase the frequency and severity of future heatwaves, these results highlight an emerging trend. It suggests that further research should focus on possible changes in future death rates, taking into account population and demographic changes.
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June 30, 2016
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https://www.sciencedaily.com/releases/2016/06/160630093233.htm
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Radiography of drought periods in Spain from the last 318 years
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The Mediterranean Basin has been witness to increased droughts for at least five decades, but has this always been the case? A team from the University of Zaragoza has been successful in reconstructing, for the first time, the droughts from 1694 to 2012 based on the precipitation index and the study of tree growth rings. According to the study, the twelve months leading up to July 2012 were the driest.
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In the Mediterranean Basin, droughts are a recurring phenomenon that negatively impacts society, economic activities and natural systems. No one seems to doubt the fact that temperatures all over the world have risen in recent decades. However, this trend does not appear to be perceived as clearly when it comes to precipitation (for which data from 1950 onwards is available). Thus, up until now, the study on the recurrence and severity of droughts in Spain has been based on information from weather stations, with sufficient data only as of the mid-twentieth century.To test the evolution of the droughts, scientists from the Department of Geography at the University of Zaragoza utilised indirect information, such as the study of tree growth rings, to reconstruct the climate of the Iberian Range as far back as 1694 and to analyse dry periods using the Standardised Precipitation Index (SPI). The researchers collected 336 samples and 45,648 growth rings from five different species (P. sylvestris, P. uncinata, P. nigra, P. halepensis, and Pinus pinaster) from 21 locations in the province of Teruel, in the east of the Iberian Peninsula, at an average altitude of 1,600 metres.The results, published in the 'International Journal of Biometeorology', made it possible to evaluate droughts from the last three centuries; they reveal that the twelve months leading up to July 2012 were the driest over the entire period studied. "We have been able to successfully identify seven especially dry periods and five wet periods since the end of the 17th century," says Ernesto Tejedor to Sinc, the main author of the study.According to the researchers, in addition to these periods there have been 36 extremely dry years and 28 very wet years since the end of the 17th century. "Some of these dry years, such as 1725, 1741, 1803 and 1879, are also identified in other drought reconstructions in Romania and Turkey, thus demonstrating the larger-scale coherence of the extreme deviations and their relationship with increasingly global atmospheric processes," adds Tejedor.Many of these extreme events are associated with catastrophic historical and cultural changes from the last three centuries. In fact, 1725 is known as 'The year without a harvest' in Monegros. These events are reflected in historical documents as the 'pro-pluvia' rogations, "since the intense droughts led to bad harvests with serious consequences for society," comments Tejedor.The reconstruction of droughts using dendrochronology does not make it possible to directly predict extreme future events, although these reconstructions are indeed used to validate future climate change models. "What we are seeing from the 20th century, and what we have seen so far in the 21st, is an increase in the recurrence of extreme phenomena, including both wet and dry years," stresses the researcher to Sinc.For the expert, predictions for precipitation variability and trends are not yet reliable like those for temperature, as other factors which are still being studied also play a role.
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June 29, 2016
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https://www.sciencedaily.com/releases/2016/06/160629160513.htm
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El Niño could drive intense season for Amazon fires
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The long-lasting effects of El Niño are projected to cause an intense fire season in the Amazon, according to the 2016 seasonal forecast from scientists at NASA and the University of California, Irvine.
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El Niño conditions in 2015 and early 2016 altered rainfall patterns around the world. In the Amazon, El Niño reduced rainfall during the wet season, leaving the region drier at the start of the 2016 dry season than any year since 2002, according to NASA satellite data."It's the driest we've seen it at the onset of a fire season, and an important challenge now is to find ways to use this information to limit damages in coming months," said Jim Randerson, Chancellor's Professor of Earth system science at UCI. He developed the forecast methodology with UCI research scientist Yang Chen and colleagues at NASA Goddard Space Flight Center. "Just as El Nino is known to have an impact on precipitation in the western United States, it also affects the Amazon, but in that case it causes drier conditions."Wildfire risk for the dry-season months of July, August and September this year now exceeds the danger in 2005 and 2010, drought years when large areas of Amazon rainforest burned, said Doug Morton, NASA Earth scientist."Severe drought conditions at the start of the dry season set the stage for extreme fire risk in 2016 across the southern Amazon," Morton said.The forecast uses the relationship between climate and active burn detections from NASA satellites to predict fire season severity during the region's dry season. Developed in 2011, the forecast model is focused particularly on the link between sea surface temperatures and fire activity. Warmer sea surface temperatures in the tropical Pacific (El Niño) and Atlantic oceans shift rainfall away from the Amazon region, increasing the risk of fires during dry season months.The team also uses data on terrestrial water storage from a joint NASA/German mission to follow changes in groundwater during the dry season. Satellite measurements serve as a proxy for the dryness of soils and forests.For 2016, El Niño-driven conditions are far drier than 2005 and 2010 -- the last years when the region experienced drought. The team has also developed a web tool to track the evolution of the Amazon fire season in near real time. Estimated fire emissions from each forecast region are updated daily, based on the relationship between active detections -- made by the Moderate resolution Imaging Spectroradiometer instrument on NASA's Terra satellite -- and fire emissions data from the Global Fire Emissions Database in previous years. So far, however, the region has seen more fires to date than those years, another indicator that aligns with the fire severity forecast.Fires in the Amazon have local, regional, and long-distance impacts. Agricultural fires that escape their intended boundaries can damage neighboring croplands and Amazon forests. Even slow-moving forest fires cause severe degradation, as the rainforest trees are not adapted to burns. Together, intentional fires for agricultural management, deforestation, and wildfires generate massive smoke plumes that degrade regional air quality, exacerbating problems with asthma and respiratory illness. Smoke eventually flows south and east over major urban centers in southern Brazil, including São Paulo and Rio de Janeiro, contributing to air quality concerns."When trees have less moisture to draw upon at the beginning of the dry season, they become more vulnerable to fire, and evaporate less water into the atmosphere," said Randerson. "This puts millions of trees under stress and lowers humidity across the region, allowing fires to grow bigger than they normally would."While scientists have been working with South American officials to broadcast the results of the forecasts and increase awareness of fire risk, they also said that the work could lead to better wildfire forecasts in other regions of the world. The team recently identified nine regions outside the Amazon where fire season risk can also be forecast three to six months ahead of peak activity. It may be possible to build operational seasonal fire forecasts for much of Central America and for many countries in Southeast Asia, Randerson said.
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June 29, 2016
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https://www.sciencedaily.com/releases/2016/06/160629125821.htm
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Northern bird found to be more resilient to winter weather
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One of the UK's most widespread songbirds, the Wren, varies in its resilience to winter weather depending on where it lives in Britain -- according to new research from the University of East Anglia and the British Trust for Ornithology.
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Findings published today in the Populations of small birds may decline following periods of cold winter weather, something that is probably linked to low temperatures and difficulties in finding sufficient insect prey.Researchers at the British Trust for Ornithology (BTO) and UEA's School of Biology studied one of the UK's smallest songbirds, the Wren.They found that populations inhabiting regions where winters are more severe show some form of adaptation.The team used information on Wren populations that had been collected by volunteers participating in the Breeding Bird Survey -- the main scheme for monitoring the population changes of the UK's common breeding birds, run by the BTO, the RSPB and the Joint Nature Conservation Committee (JNCC).The researchers found that Wren populations were susceptible to severe winter weather, measured in terms of the number of days with a ground frost. However, northern populations were found to be resilient to winters with up to 70 per cent more frost days than southern populations, suggesting a degree of local adaptation.James Pearce-Higgins, BTO director of Science and one of the authors, said "This work indicates that each Wren population is closely adapted to its local climate. There was a close correlation between the historic regional climate and the degree to which the population was resilient to severe winters."Using information collected by bird ringers, the team also found that Wren body mass was approximately 5 per cent lower in the warmest (south-west) than in the coldest (east Scotland) region.Lead author Catriona Morrison, from UEA, said: "Large individuals are likely to be favoured in colder regions due to the thermal advantage of larger size and their ability to store more body fat. Our findings match the pattern seen more wildly across other species -- a pattern known as Bergmann's rule."The findings of this study have particular relevance to our understanding of how birds and other species respond to climate change.Although this work shows that wren populations may adapt to at least some change in temperature, they are short-lived and therefore probably more adaptable than most other bird species.Ultimately, the ability of species to cope with climate change will depend upon whether the future rate of warming exceeds their ability to adapt.
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June 28, 2016
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https://www.sciencedaily.com/releases/2016/06/160628182622.htm
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New study shows impact of human-made structures on Louisiana's coastal wetlands
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As Louisiana's wetlands continue to disappear at an alarming rate, a new study has pinpointed the human-made structures that disrupt the natural water flow and threaten these important ecosystems. The findings have important implications for New Orleans and other coastal cities that rely on coastal wetlands to serve as buffer from destructive extreme weather events.
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Scientists at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science found that human-made canals limit the natural tidal inundation process in roughly 45 percent of the state's coastline, and disruptions from levees accounted for 15 percent."This study demonstrates that human infrastructure development along coastal areas have long-term consequences on the ability of coastal wetlands to adapt to sea-level rise and other processes that reduce the size of coastal wetlands," said Talib Oliver-Cabrera, the study's first author and a UM Rosenstiel School Ph.D. student.Coastal wetlands in Louisiana are economically and esthetically important by providing storm protection, flood control, and essential habitats for a myriad of wildlife. They support economically important commercial and recreational fishing industries, tourism, and oil and gas industries.Human-made structures, such as levees and canals, have changed the regular patterns of tidal inundation in coastal wetlands and have become a main element in determining coastal wetland distribution.Using a remote sensing technique, called Interferometric Synthetic Aperture Radar (InSAR), the researchers analyzed water-level changes in Louisiana's coastal wetlands that occurred due to tidal inundation. Based on the detected changes observed, they were able to determine the extent of tidal inundations along the Louisiana coast."Our analysis showed that tidal inundation along Louisiana's coastline is restricted to narrow areas due to the presence of human-made canals and levees that disrupt the regular tidal flow through the coastal wetlands," said study co-author Shimon Wdowinski, a research professor of marine geosciences at the UM Rosenstiel School. "To protect these valuable resources, it is important to study them and quantify what is causing wetland loss in coastal Louisiana," said Wdowinski.
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June 24, 2016
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https://www.sciencedaily.com/releases/2016/06/160624110035.htm
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Researchers offer new theory on how climate affects violence
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Researchers have long struggled to explain why some violent crime rates are higher near the equator than other parts of the world. Now, a team of researchers have developed a model that could help explain why.
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This new model goes beyond the simple fact that hotter temperatures seem to be linked to more aggressive behavior.The researchers believe that hot climates and less variation in seasonal temperatures leads to a faster life strategy, less focus on the future, and less self-control -- all of which contribute to more aggression and violence."Climate shapes how people live, it affects the culture in ways that we don't think about in our daily lives," said Brad Bushman, co-author of the study and professor of communication and psychology at The Ohio State University.Paul van Lange, lead author of the study and a professor of psychology at the Vrije Universiteit Amsterdam (VU) added, "We believe our model can help explain the impact of climate on rates of violence in different parts of the world."The researchers, which included Maria I. Rinderu of VU, call the new model CLASH (CLimate Aggression, and Self-control in Humans). They describe the CLASH model in an online article in the journal Many studies have shown that levels of violence and aggression are higher in hot climates, according to the researchers."But the two leading explanations of why that is so aren't satisfactory," Bushman said.The General Aggression Model (which Bushman helped develop) suggests hot temperatures make people uncomfortable and irritated, which makes them more aggressive. "But that doesn't explain more extreme acts, such as murder," he said.Another explanation (Routine Activity Theory) is that people are outdoors and interacting more with others when the weather is warm, which leads to more opportunities for conflict. But that doesn't explain why there's more violence when the temperature is 95 degrees F (35 °C) than when it is 75 degrees F (24 °C) -- even though people might be outside under both circumstances.The CLASH model states that it is not just hotter temperatures that lead to more violence -- it is also climates that have less seasonal variation in temperature."Less variation in temperature, combined with heat, brings some measure of consistency to daily life," Rinderu said.That means there is less need to plan for large swings between warm and cold weather. The result is a faster life strategy that isn't as concerned about the future and leads to less need for self-control."Strong seasonal variation in temperature affects culture in powerful ways. Planning in agriculture, hoarding, or simply preparing for cold winters shapes the culture in many ways, often with people not even noticing it. But it does shape how much a culture values time and self-control," Van Lange said."If there is less variation, you're freer to do what you want now, because you're not preparing foods or chopping firewood or making winter clothes to get you through the winter. You also may be more concerned with the immediate stress that comes along with parasites and other risks of hot climates, such as venomous animals."People living in these climates are oriented to the present rather than the future and have a fast life strategy -- they do things now."We see evidence of a faster life strategy in hotter climates with less temperature variation -- they are less strict about time, they have less use of birth control, they have children earlier and more often," Bushman said.With a faster life strategy and an orientation toward the present, people have to practice less self-control, he said. That can lead people to react more quickly with aggression and sometimes violence.The theory is not deterministic and isn't meant to suggest that people in hotter, consistent climates can't help themselves when it comes to violence and aggression."How people approach life is a part of culture and culture is strongly affected by climate," Van Lange said. "Climate doesn't make a person, but it is one part of what influences each of us. We believe it shapes the culture in important ways," he said.Since CLASH is a new theory, studies have to be done to prove it is correct. But Bushman said a lot of evidence already suggests that the theory may be on to something."We believe CLASH can help account for differences in aggression and violence both within and between countries around the world," he said. "We think it provides a strong framework for understanding the violence differences we see around the world."
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June 23, 2016
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https://www.sciencedaily.com/releases/2016/06/160623150113.htm
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Better information needed to understand extreme weather
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Scientists need more credible and relevant information to help communities become more resilient to extreme weather events such as floods, a University of Exeter expert has said.
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Researchers need improved techniques to be able to understand why the climate is changing, and the part humans play in this process, according to Professor Peter Stott, who also leads the Climate Monitoring and Attribution team at the Met Office.In an article in the journal "Placing recent extreme events in the context of past and future climate variability and change would enhance the ability of societies to manage weather and climate-related risks," Professor Stott says in the article.Climate change caused by humans has led to an overall increase in the frequency and intensity of daily temperature extremes and has led to more extreme rain over the world as a whole. But the risks of unusual weather events such as floods, droughts, and heat waves have changed differently in different parts of the world. More research is needed to understand exactly how communities are being affected by climate change.Professor Stott co-edits an annual report explaining how the climate has affected extreme events of the previous year. The report has grown from considering only six events in 2011 to covering 28 different events in 2014. These reports help to explain if climate change has influenced either the magnitude or the probability of specific types of weather events.Most researchers use mathematical modelling to help assess the extent of climate change. It is easier for them to find evidence that human-induced climate change causes extreme temperatures because there is a wealth of data on extreme hot and cold events and they can be well captured in climate models. Heatwaves occur over a wide area.It is more difficult to examine extreme rainfall because there is a lack of accurate data, climate models can fail to represent them adequately, and their relationship with climate variability and change is often not well understood. Flooding is often extremely localised. Scientists are trying to rectify this through projects, including the European project EUCLEIA (European Climate and Weather Events: Interpretation and Attribution) which is led by Professor Stott and a team from the Met Office.Professor Stott believes better ways of modelling and analysing climate change will be available very soon. He said: "I believe there is the potential for improvement in our ability to attribute extreme weather events within the next year or two. It is both possible to do this and important that we do. With this information societies will be in a better position to manage the risks of weather and climate-related disasters."
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Weather
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June 23, 2016
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https://www.sciencedaily.com/releases/2016/06/160623095248.htm
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Ocean forecast offers seasonal outlook for Pacific Northwest waters
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By now we are used to the idea of seasonal weather forecasts -- whether to expect an El Niño ski season, or an unusually warm summer. These same types of climate models are now being adapted to make seasonal forecasts for the region's coastal waters.
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Researchers from the University of Washington and the National Oceanic and Atmospheric Administration have created a seasonal outlook for the Pacific Northwest waters, which would help tell if it's going to be a great year for sardines or a poor crab season. A paper evaluating the forecast's performance was published in June in the interdisciplinary, open-access journal "Ocean forecasting is a growing field, and the Pacific Northwest coast is a particularly good place to use this approach," said lead author Samantha Siedlecki, a research scientist at the UW-based Joint Institute for the Study of the Atmosphere and Ocean. "This paper is doing what the scientific community asks of a new tool, which is assessing how well it performs."The tool, called JISAO Seasonal Coastal Ocean Prediction of the Ecosystem, or J-SCOPE, launched in summer 2013. The new paper is the first formal evaluation of how well it works. Analysis of the first three years of forecasts confirms that they do have measurable skill on seasonal timescales.The seasonal forecasts for water oxygen, temperature, chlorophyll and pH along the coast of Washington, Oregon, Puget Sound and Canada's Vancouver Island have been posted for the past three years on the UW-based Northwest Association of Networked Ocean Observing Systems website. That site now offers a comparison between the forecasted values and the long-term average, and the probability for different scenarios."The forecasts have been evolving over the years," Siedlecki said. "We're trying now to put the forecast in context -- is this better or worse than in recent years?"Analyses in the new paper show that the tool does especially well at the beginning of the spring upwelling season and matches observations most closely below the surface. This is good, Siedlecki said, because that's exactly where measurements are scarce."Our tool has more skill in the subsurface for things like bottom temperature and bottom oxygen," she said. "That's exciting because it can inform us where and when the low-oxygen and corrosive conditions that can be stressful to marine life would likely develop."The fall season is more storm-driven, she said, and consequently difficult to predict.The tool takes long-term NOAA forecasts and combines those with a regional ocean model to produce the outlook. The goal is to eventually combine the ocean forecasts with fisheries management, so that decisions surrounding quotas could take into account the conditions for the species' habitat during the coming season.A sardine forecast was recently added and was the focus of a separate NOAA-led paper published this winter in The group now has funding from NOAA's Northwest Fisheries Science Center to work on forecasts for hake, also known as Pacific whiting, since the widely-fished species lives below the surface and seems sensitive to oxygen concentrations. The researchers are interested in developing similar forecasts for salmon and other species.Forecasted values include pH and aragonite, a calcium-containing mineral that marine animals use to harden their shells, so the tool can also help predict which months will have good conditions for growing shellfish."The oyster industry has already been treating the intake seawater coming into the hatcheries," Siedlecki said. "If our forecasts can help the growers identify times of year that would be most suitable to set up juvenile oysters out in the open ocean, that would potentially help them get a leg up on changing conditions."For this summer, the outlook may be good news for ocean swimmers who like warm water and bottom-dwelling fish that sometimes struggle to breathe in the late summer or early fall."The current forecast is showing weak upwelling, warmer temperatures and higher oxygen than we've had in the past, so a bit of a relief in some ways for the ecosystem," Siedlecki said.
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Weather
| 2,016 |
June 24, 2016
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https://www.sciencedaily.com/releases/2016/06/160624140710.htm
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Computer models show park microclimates improve city life
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Computer modelling based on microclimate data from a Malaysian public park has shown how adding trees and grass can improve living conditions in dense city cores.
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Most people appreciate urban parks for their aesthetic and social worth. In hot climates, the right mix of ground cover, plant and tree foliage can noticeably improve local microclimates to make inner cities more liveable, say researchers at the Universiti Teknologi MARA in Malaysia.They placed portable weather stations in and around a lakeside park near the university to document the microclimate among its dense, mature plants. They then used the collected data to create computer models that demonstrate the effects of adding more trees and replacing all plants with ground cover.The results of a simulated park with denser trees showed, unsurprisingly, that the park's shady canopy harboured lower temperatures, slightly higher humidity and more airflow when compared with a simulated park with only ground cover. Using data modelling, the researchers were able to add about 80% more shade cover to the model to gain a significant increase in human comfort. They suggest further research should be done to gain a better understanding of the sizes and varieties of trees best suited to improve local conditions."The results showed that the density of the mature trees played an important role," say the researchers. They note that adding more, taller trees to the baseline model of the park yielded reduced temperatures and improved airflow, which the plants channelled through the park to create a more comfortable climate for humans.Improved conditions were also elicited by increasing the ground cover vegetation, by planting cow grass, for example, and by increasing the numbers of mature trees such as the rain tree (Samanea saman), angsana (Pterocarpus indicus) and the yellow flame tree (Peltophorum pterocarpum).The researchers say that, in addition to adding cooling shade to an area, trees shelter local wildlife, can help mitigate pollution, and can also reduce the energy needed to control climates within nearby buildings. While they couldn't extend their data set to model the entire urban area, they say developing such a model would be worthwhile, since adding treed parks can reduce the "urban heat island effect," which traps warm air and contributes to heat stress among inner city dwellers.In the future, the researchers plan to propose an outdoor thermal comfort model that reflects the adaptive responses of humans to heat stress.
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June 22, 2016
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https://www.sciencedaily.com/releases/2016/06/160622114749.htm
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Wild boars and wart hogs may have an internal compass
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New research suggests for the first time that wild boars and wart hogs have an internal magnetic compass that helps them orient themselves as they forage for food and inhabit new areas.
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For the study, investigators observed 1614 wild boars at 31 different localities in the Czech Republic and 1347 warthogs at 33 different localities in six African countries. The animals had a highly significant axial preference to align themselves approximately along the magnetic north-south axis, with a slight shift towards east. The time of the day, season, and weather conditions had no significant influence on the average directional preferences of wild boars or warthogs."The fascinating findings add on to a well growing body of evidence for a magnetic sense in mammals. The interesting questions that arise now are how they are able to sense the magnetic field and whether they really use it for navigation" said Dr. Pascal Malkemper, senior author of the
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June 22, 2016
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https://www.sciencedaily.com/releases/2016/06/160622104806.htm
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Acoustics researcher finds explanation for auroral sounds
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In 2012, a research group headed by Aalto University Professor Unto K. Laine proved that the source of sounds associated with the Northern Lights is located close to the ground at an altitude of approximately 70 meters. Now, by combining his measurements with the temperature profiles measured by the Finnish Meteorological Institute, Professor Laine has found an explanation for the mechanism that creates the sound. According to the new inversion layer hypothesis, the popping and crackling sounds associated with the Northern Lights are born when the related geomagnetic storm activates the charges that have accumulated in the atmosphere's inversion layer causing them to discharge.
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'Temperatures generally drops the higher the altitude. However, when temperatures are well below zero and, generally in clear and calm weather conditions during the evening and night, the cold is near the surface and the air is warmer higher up. This warm air does not mix, instead rising up towards a colder layer carrying negative charges from the ground. The inversion layer forms a kind of lid hindering the vertical movements of the charges. The colder air above it is charged positively. Finally, a geomagnetic storm causes the accumulated charges to discharge with sparks that create measurable magnetic pulses and sounds' Mr Laine, who is now a professor emeritus, explained.Unto K. Laine carried out the recordings that form the basis for his research on 17 and 18 March 2013, when Southern Finland was treated to exceptionally splendid Northern Lights.'I recorded hundreds of sound events in Fiskars where the temperature was at -20 °C. I selected the 60 loudest events, the sources of which were directly above the recording microphone array. The magnetic pulses that preceded these sounds proved that their sources were at an altitude of approximately 75 meters. On the same night, the Finnish Meteorological Institute carried out its own measurements, which proved that the inversion layer was located at the same altitude where these noises were born. The correlation between the strength of the magnetic pulses and the loudness of the sounds was also strong.According to Mr Laine, the inversion layer hypothesis also gives a credible explanation for why auroral sounds have only been heard in calm weather conditions.'Even a small wind can prevent the birth of an inversion layer, which means no sounds will be created,' he summarised and said that he had experienced the inversion layer's effect already when living in Ostrobothnia as a small boy.'When the weather was calm in winter, smoke from cottage chimneys rose straight up in a vertical line, stopped abruptly and began to spread into a horizontal dome over the village,' Professor Laine reminisces.He emphasises that the hypothesis does not rule out other mechanisms. However, this provides the first explanation for all three mysteries related to auroral sounds.'In addition to the mechanism behind the sound, this helps us understand how we can hear the sound when the auroral light source is at a distance of 80-100 km. The inversion layer hypothesis also provides answers to how it is possible that sound events occur almost simultaneously with visual observations: from an altitude of 75 meters the sound reaches the human ear in just 0.2 seconds.The research Auroral Acoustics project -- a progress report with a new hypothesis was presented on 22 June at the Baltic-Nordic Acoustic Meeting in Stockholm, Sweden.
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June 21, 2016
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https://www.sciencedaily.com/releases/2016/06/160621111218.htm
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Significant humus loss in forests of the Bavarian Alps
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Alpine forests will be at great risk should weather phenomena such as droughts and torrential rain become more frequent. As a study by the Technical University of Munich (TUM) shows, the mountain forests of the Bavarian Alps have seen a significant reduction in topsoil organic matter over the past three decades. The study authors' recommendation is therefore to preserve, or better still, increase soil humus regardless of climate change by implementing humus-promoting forest management to safeguard the mountain forest's protective function and to mitigate floods.
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Humus stocks are essential for soil fertility, water balance and nutrient supply of the soil. Previous studies established that especially in cooler mountain regions, carbon bound in soil organic matter reacts very sensitively to warmer weather caused by climate warming, and is increasingly released by microorganisms. As a consequence, the soil loses one of its essential features: its capacity to store carbon, which, after being released, also contributes to global warming.So far, no exact data existed as to the changes in humus stocks of Alpine soil over the years, and any calculations to this effect are rather imprecise. Scientists at the Technical University of Munich have now published a new study in One of the two studies looked at all major forest and soil types across the entire 1,700 square mile area of the Bavarian Alps between 1986 and 2011. The second study observed typical mountain spruce forests in the Berchtesgaden region (total area: 230 square miles) from 1976 onward."I was surprised to see that the humus stocks of forest soils have seen such a dramatic -- and in statistical terms significant -- degree of depletion," says Professor Joerg Prietzel of the Chair of Soil Science at TUM. During the period under investigation, the topsoil organic matter stock of forest soils in the Bavarian Alps declined by an average of approximately 14 percent.The heaviest depletion occurred in soils with limestone or dolomite parent material. They suffered a loss of just under one third of their humus mass. "Overall, the conclusions drawn from the two studies -- despite employing different approaches and covering different regions -- are almost identical," explains lead author Prietzel. No silvicultural usage of the areas under investigation took place during the study. Humus depletion must hence be a result of climate change.The soil organic matter decline is highly likely to be a consequence of climate warming, which has been recorded by weather stations in the Bavarian Alps over the past hundred years -- in particular in more recent decades."The Alps in the Berchtesgaden region have been affected quite dramatically," explains Prof. Prietzel, "as mean air temperature there has seen a particularly drastic rise during summer months." In connection with increased temperatures during the summer months, regions where air temperatures are on the up also experience a warming of the ground, which presumably is the primary cause for the progressive degradation of soil organic matter.In contrast to forest soils, mountain pasture soils examined in the Berchtesgadener Alps suffered no humus loss in the past 30 years. However, they tend to be without exception less humus-rich than directly adjoining forested soils.The authors of the study suspect that the mountain pastures, which many hundreds of years ago also used to be wooded areas before the advent of alpine farming, must have lost a considerable portion of their original humus stock relatively soon after the forests had been cleared to make room for the pastures. The remaining soil organic matter is not -- as is frequently the case with forest soil -- mostly present as "forest floor" in the surface layer, but lies deeper underground where it is better protected from humus-degrading microorganisms.Ultimately, the study authors expect average summer temperatures in the Alps to keep rising, coupled with an increase in extreme weather episodes. Hence, we will see more and more extended periods of no rain at all alternating with heavy rain.A thick humus layer with great water storage capability is able to mitigate the effects of such extreme weather on mountain forests and the mountain landscape. It stores water for trees and the Alpine flora, while at the same time reducing floodwaters after heavy downpours. In order to preserve such vital functions of the humus layer, the climate-change-based humus degradation must be proactively countered by promoting humus restoration.Of central importance in this scenario are "resilient" mountain forests that can withstand extreme incidents. Such forests are characterized by being made up of a diverse range of different tree species and trees of varying ages. Trees of such forests yield a continuous supply of stray litter such as leaves, needles, roots or brushwood, and maintain a constant cool "forest climate," even during hot summers, which in turn slows down humus degradation by soil microorganisms. What's more, they also prevent erosion-borne humus loss as a result of downpours, snow gliding or avalanches.
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Weather
| 2,016 |
May 7, 2021
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https://www.sciencedaily.com/releases/2021/05/210507093755.htm
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Oat crops: Winning gene combination takes all
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Researchers have traced the remaining last steps of the biological pathway that gives oats resistance to the deadly crop disease take-all.
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The discovery creates opportunities for new ways of defending wheat and other cereals against the soil-borne root disease.The research team have already taken the first step in this aim by successfully reconstituting the self-defence system in the model plant Nicotiana benthamiana.Further experiments to establish the avenacin biosynthetic pathway in wheat's more complex genome, to test if it will provide the same resistance to take-all and other diseases, have already been initiated in collaboration with the National Institute of Botany (NIAB) in Cambridge.The research by CEPAMS -- a collaboration between the John Innes Centre and the Chinese Academy of Sciences -- also delivers fresh insights into the mechanisms that shape genome architecture and adaptive evolution in plants.Avenacins are antimicrobial compounds synthesised in the roots of oats where they offer protection against soil-borne diseases such as take-all. This fungal pathogen causes huge yield losses in wheat and there is no effective means of control.Wheat and other cereals and grasses do not make these compounds but a better understanding of how they are produced in oat will give crop scientists knowledge they need to create disease resistant lines of wheat using modern technologies.Earlier experiments had characterised and cloned ten avenacin biosynthetic pathway genes found in the oat genome.Here, using a genomics-driven approach, with sequencing carried out by Professor Bin Han's group at the Chinese Academy of Sciences, the team elucidated the complete pathway, encoded by 12 genes.They found that genes are clustered next to each other in the genome like beads on a string and organised along the chromosome approximately in the same order as the biosynthetic pathway -- like a recipe written out in order of ingredients.The avenacin gene cluster is located very close to the end of one arm of chromosome 1 of oat. It is arranged such that the early pathway genes are closer to the end of the chromosome (the telomere) and the late pathway genes are further in.The team speculate this may be because gene mutations in the late avenacin pathway can result in the accumulation of compounds that negatively affect plant growth while mutations in the early pathway genes do not.The orientation of these late pathway genes away from the telomere region means the plant is less likely be affected by toxins.Comparison with the sequenced genomes of other cereals and grasses revealed that the avenacin cluster has formed since the divergence of oats from these other plant species which, the researchers presume, is due to a particular set of selective pressures.Professor Anne Osbourn, joint corresponding author of the research along with Professor Bin Han said: "Our investigations show that plant genomes are able to shuffle and evolve their genes to enable them to adapt to particular stresses -- in this case to soil-borne fungal diseases such as take-all. During this process, winning combinations of genes that provide a selective advantage can be recruited and relocated from around the genome and assembled into a cluster like beads on a string. This clustering will enable the winning gene-set to be passed on from generation to generation and mitigate against incomplete inheritance of the pathway genes with associated deleterious effects."The study offers the latest example of plant biosynthetic gene clusters for different types of compounds including drugs.Investigations of how widespread these types of genomic organisations are in the Plant Kingdom hinges on the generation of new genome sequences for a wider variety of plants.
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Agriculture & Food
| 2,021 |
May 3, 2021
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https://www.sciencedaily.com/releases/2021/05/210503172827.htm
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Revealing the secret cocoa pollinators
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The importance of pollinators to ensure successful harvests and thus global food security is widely acknowledged. However, the specific pollinators for even major crops -- such as cocoa -- haven't yet been identified and there remain many questions about sustainability, conservation and plantation management to enhance their populations and, thereby, pollination services. Now an international research team based in Central Sulawesi, Indonesia and led by the University of Göttingen has found that in fact ants and flies -- but not ceratopogonid midges as was previously thought -- appear to have a crucial role to play. In addition, they found that promoting biodiversity friendly landscapes, leaf-litter and trees providing shade in agroforestry systems were important to enhance tiny cocoa pollinators. The research was published in
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The team, in collaboration with Tadulako University in Palu, carried out two separate experiments involving 42 cocoa agroforestry farms in the Napu Valley of Central Sulawesi. The work included applying a sticky glue to over 15,000 flowers in more than 500 trees for an eight-month period and recording the identity and abundance of captured flower visitors. In one experiment involving 18 farms, they investigated the effect of the distance between the forest and the farm, and the amount of canopy cover from shade trees, on the abundance of the main pollinators. In the second experiment in 24 different cocoa farms, they measured the effect of leaf-litter management on pollinators. In both experiments they quantified the amount of forest and agroforests surrounding the 42 cocoa farms.The researchers found that ants were the most common flower-visitors. This highlighted their potential as pollinators whether directly (by transporting pollen), or indirectly (by disturbing pollinators and promoting their movement). The study also shows that preserving biodiversity friendly landscapes, such as forests and agroforests, and promoting agroforestry systems is crucial for pollinator conservation. This in turn pro-motes pollination and sustainable cocoa production. "We were surprised that we did not capture any cerato-pogonid midges, even though these tiny midges were considered the most important pollinators of cocoa. This emphasizes that cocoa pollinators are more diverse than previously known but also that there is still much to learn," said Dr Manuel Toledo-Hernández, from the University of Göttingen and first author of the study. "Current global cocoa initiatives should consider the role of biodiversity friendly habitats for the con-servation of pollinators, because their pollination services are an ecological alternative towards current commitments on combining high yields with conservation," added Toledo-Hernández and his coauthors Teja Tscharntke and Thomas C. Wanger.
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Agriculture & Food
| 2,021 |
April 22, 2021
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https://www.sciencedaily.com/releases/2021/04/210422181848.htm
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Finding new life for wine-grape residue
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California produces nearly 4 million tons of world-class wine each year, but with that comes thousands of tons of residue like grape skins, seeds, stems and pulp. What if scientists could harness that viticultural waste to help promote human health?
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Maybe they can, according to new research from food scientists at the University of California, Davis. In a study published in the journal Oligosaccharides are found in many plant and animal tissues, including human breast milk. Recent advances have revealed oligosaccharides' vast potential to support intestinal health."We were surprised by the diversity of the oligosaccharides in the chardonnay wine grapes, including the presence of structural elements found in mother's milk," said Amanda Sinrod, lead author and a master's candidate working with Professor Daniela Barile.The UC Davis team analyzed the molecular composition of chardonnay residue provided by Jackson Family Wines and Sonomaceuticals, a company founded by two food industry businesswomen to develop new uses for viticulture waste. Wine-grape pomace, or marc, comprises about 30 percent of the original wine-grape material, and much of it is left to decompose in the sun."It's all about sustainable wine production and finding a second life for wine grapes," Barile explained. "Up to this point, chardonnay marc has been regarded as a byproduct of winemaking with little or no value. Early results are encouraging that marc could be a valuable source for oligosaccharides and other compounds that support health and nutrition."UC Davis researchers were among the first to decode the magic of oligosaccharides in mother's milk. The sugar molecules don't nourish the baby directly. Instead, they feed a strain of bacteria in the infant's intestines that helps build immunity against illness and disease. That discovery is helping scientists develop methods and products to improve human health.Barile's lab innovates technologies for recovering health-enhancing compounds from various agricultural and industrial waste streams, such as whey, legumes and chickpeas. Her team previously discovered oligosaccharides in both red and white wine residue and is pleased with preliminary findings from the chardonnay analysis."There is more research to be done, but early results are promising that chardonnay marc can become a source for developing supplements and other food products to support health," Barile said.Oligosaccharides appeared to be especially abundant in the wine-grape skins. In earlier research, scientists detected oligosaccharides in the finished wine product, but not in large concentrations. Researchers didn't include bottled wine in this study.The chardonnay marc samples were also rich in flavonoids, healthy compounds found in many fruits and vegetables. Researchers are exploring whether the oligosaccharides work independently or synergistically with these bioactive compounds to support intestinal health. The team is studying how growing conditions, vintages and processing might affect the health potential of viticulture waste."We observed significant differences in the relative abundance and type of oligosaccharides in different parts of the marc, so further research is needed to maximize their potential in food product design," Sinrod said.The UC Davis team included Cooperative Extension Specialist Selina Wang and Xuequi Li with the Olive Center, and Mrittika Bhattacharya and Bruna Paviani with the Department of Food Science and Technology.
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Agriculture & Food
| 2,021 |
April 22, 2021
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https://www.sciencedaily.com/releases/2021/04/210422102833.htm
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Plant provenance influences pollinators
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Insect decline is one of the greatest challenges facing our society. As a result of the destruction of many natural habitats, bees, bumblebees, butterflies, beetles and the like find less and less food. As a consequence, they are barely able to fulfil their role as pollinators of wild and cultivated plants. This trend is increasingly noticeable in agricultural regions in particular.
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Researchers at the University of Münster have now taken a more detailed look at how the choice of seeds in restoration measures -- i.e. the restoration of natural habitats at degraded land -- affects how insects benefit from these measures. Here, not only the plant species plays an important role, but so does the geographical provenance of the seeds used -- because the provenance influences not only insect diversity but also how often the pollinators visit flowers. The results of the study have been published in the Insects are indispensable for the functioning of ecosystems -- and for human survival. They are necessary, for example, for the pollination of many cultivated plants which are, in turn, an essential source of nutrition for humans. In regions characterized by agriculture or in built-up areas with settlements and cities, there are reduced resources available to pollinators. In order to support them in their pollination, flower-rich habitats are created in the landscape, often in the form of wildflower stripes.When flower stripes or other habitats are created, however, it should be taken into account that plant species are not homogeneous entities, as their populations genetically differ. This differentiation often occurs as a result of population adaptation to their local environment. A brown knapweed, for example, which grows near the sea -- where frost is rare -- will be less frost-resistant than a brown knapweed which grows in the mountains, where frost is common. The differences can be seen in many plant traits, and some of these differences can influence pollinators, for example the number of flowers or the time when they flower. "Depending on the provenance, some populations flower earlier than others," as Dr. Anna Lampei Bucharová from Münster University's Institute of Landscape Ecology explains, who also lead the study. "When setting up habitats for pollinators, these within-species differences have so far often been neglected," she adds, "and the plants are mostly selected regardless of their provenance. This is why we tested to see whether the provenance of the plants influences pollinators."The geographical provenance of the seeds plays a key role in this context. In a field experiment, the researchers formed small experimental plant communities which had exactly the same species composition but different provenances. The populations came from the Münster region, from the area around Munich and from greater Frankfurt an der Oder. They then recorded flowering data, observed the pollinators visiting these communities, and compared the frequency and diversity of the pollinators in communities with different provenances.The researchers discovered that a plant's provenance influences pollinators -- both how often the pollinators visit flowers and also the diversity of the insect species. "The effect can be considerable," says Dr. David Ott, co-author of the study. "We observed twice as many visits by pollinators at flowers of one provenance than at flowers of another provenance. The most important parameter driving this is the phenology of the plant's flower -- in other words, the temporal sequence of flowering," he adds. The researchers conclude that plants from some provenances started to flower earlier and more intensively than others, and so they presented more flowers and, as a result, interacted more frequently with pollinators.The results are important both for scientists and for ecological restoration. The researchers are confident that Germany provides good conditions for implementing provenance-based restoration strategies, because regional ecotypes of many species are readily available in the so-called "Regiosaatgut" ("regional seeds") system. This system provides regional seeds for many species for up to 22 regions in Germany. Thus, by selecting the appropriate plant origins, resources for pollinators could be sustainably improved.
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Agriculture & Food
| 2,021 |
April 20, 2021
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https://www.sciencedaily.com/releases/2021/04/210420183157.htm
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Predicting the next pandemic virus is harder than we think
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The observation that most of the viruses that cause human disease come from other animals has led some researchers to attempt "zoonotic risk prediction" to second-guess the next virus to hit us. However, in an Essay publishing April 20th in the open access journal
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So-called zoonotic viruses have caused epidemics and pandemics in humans for centuries. This is exactly what is occurring today with the COVID-19 pandemic: the novel coronavirus responsible for this disease -- SARS-CoV-2 -- emerged from an animal species, although exactly which species is uncertain.Therefore, a key question is whether we can predict which animal or which virus group will most likely cause the next pandemic? This has led researchers to attempt "zoonotic risk prediction," in which they attempt to determine which virus families and host groups are most likely to carry potential zoonotic and/or pandemic viruses.Dr Wille and her colleagues identify several key problems with zoonotic risk prediction attempts.First, they're based on tiny data sets. Despite decades of work, we have probably identified less than 0.001% of all viruses, even from the mammalian species from which the next pandemic virus will likely emerge.Second, these data are also highly biased towards those viruses that most infect humans or agricultural animals, or are already known to zoonotic. The reality is that most animals have not been surveyed for viruses, and that viruses evolve so quickly that any such surveys will soon be out of date and so of limited value.The authors instead argue that a new approach is needed, involving the extensive sampling of animals and humans at the places where they interact -- the animal-human interface. This will enable novel viruses to be detected as soon as they appear in humans and before they establish pandemics. Such enhanced surveillance may help us prevent something like COVID-19 ever happening again.
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Agriculture & Food
| 2,021 |
April 19, 2021
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https://www.sciencedaily.com/releases/2021/04/210419135725.htm
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Beetles that pee themselves to death could be tomorrow's pest control
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Various beetle species have gobbled through grain stores and weakened food production worldwide since ancient times. Now, researchers at the University of Copenhagen have discovered a better way of targeting and eliminating these teeny pests. Instead of using toxic pesticides that damage biodiversity, environment and human health, the researchers seek to exploit beetles' greatest strength against them -- their precisely regulated mechanism of balancing fluids.
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Up to 25 percent of global food production is lost annually due to insects, primarily beetles. For the past 500 million years, beetles have successfully spread and adapted to life around the globe and now account for one of every five animal species on Earth. Yet as far back as ancient Egypt, these tough little bugs have invaded granaries and vexed us humans by destroying our crops.As a result, food production and an abundant use of pesticides now go hand in hand. A large share of these pesticides damage biodiversity, the environment and human health. As various pesticides are phased out, new solutions are required to target and eradicate pests without harming humans or beneficial insects like bees.This is precisely what researchers from the University of Copenhagen's Department of Biology are working on. As part of a broader effort to develop more "ecological" methods of combatting harmful insects in the near future, researchers have discovered which hormones regulate urine formation in the kidneys of beetles."Knowing which hormones regulate urine formation opens up the development of compounds similar to beetle hormones that, for example, can cause beetles to form so much urine that they die of dehydration," explains Associate Professor Kenneth Veland Halberg of the University of Copenhagen's Department of Biology. He adds:"While it may seem a slightly vicious, there's nothing new in us trying to vanquish pests that destroy food production. We're simply trying to do it in a smarter, more targeted manner that takes the surrounding environment into greater account than traditional pesticides."The new study, as well as a previous study, also conducted by Kenneth Veland Halberg, demonstrates that beetles solve the task of regulating their water and salt balance in a fundamentally different way than other insects. This difference in insect biology is an important detail when seeking to combat certain species while leaving their neighbors alone."Today's insecticides go in and paralyze an insect's nervous system. The problem with this approach is that insect nervous systems are quite similar across species. Using these insecticides leads to the killing of bees and other beneficial field insects, and harms other living organisms," explains Kenneth Veland Halberg.The centrality to survival of the carefully controlled water balance of beetles is no secret. In fact, ancient Egyptians already knew to mix pebbles in grain stores to fight these pests. Stones scratched away the waxy outer layer of beetles' exoskeletons which serves to minimize fluid evaporation."Never mind that they chipped an occasional tooth on the pebbles, the Egyptians could see that the scratches killed some of the beetles due to the fluid loss caused by damage to the waxy layer. However, they lacked the physiological knowledge that we have now," says Kenneth Veland Halberg.Pesticides have replaced pebbles. And, their global use is now valued at roughly 100 billion dollars annually. But as rules for pesticide use become stricter, farmers are left with fewer options to fight pests."The incentive to develop compounds which target and eradicate pests is huge. Food production is critically dependent on pesticides. In Europe alone, it is estimated that food production would decline by 50 percent without pesticide use. With just a single, more targeted product on the market, there would almost immediately be immense gains for both wildlife and humans," states Kenneth Veland Halberg.But the development of new compounds to combat beetles requires, among other things, that chemists design a new molecule that resembles beetle hormones. At the same time, this compound must be able to enter beetles, either through their exoskeletons or by their feeding upon it."Understanding urine formation in beetles is an important step in developing more targeted and environmentally-friendly pest controls for the future. We are now in the process of involving protein chemistry specialists who can help us design an artificial insect hormone. But there is still a fair bit of work ahead before any new form of pest control sees the light of day," concludes Associate Professor Kenneth Veland Halberg.The study demonstrates that beetles regulate their kidney function in a fundamentally different way than all other insects. These differences can potentially be exploited to fatally disrupt the fluid balance of beetles without impacting other insects.The research data reports that this unique kidney function evolved about 240 million years ago, and that the mechanism has played a significant role in the extraordinary evolutionary triumph of beetles.Roughly one in five known animal species on Earth is a beetle. While 400,000 species have been described, there are thought to be well over one million beetle species in all.Researchers used the red flour beetle (The researchers got the beetle to urinate by injecting a hormone that scientists now know regulates urine formation in beetles.Wheat weevils, confused flour beetles, Colorado potato beetles and other types of beetles and insects make their ways into up to 25 percent of the global food supply every year.The problem is especially evident in developing countries, where access to effective pest control is limited or nonexistent.The project was conducted in collaboration with researchers from the University of Edinburgh, Scotland and McMaster University, CanadaThe study has just been published in the scientific journal
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Agriculture & Food
| 2,021 |
April 15, 2021
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https://www.sciencedaily.com/releases/2021/04/210415114154.htm
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Water scarcity footprint reveals impacts of individual dietary choices in US
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A lot of attention has been paid in recent years to the carbon footprint of the foods we eat, with much of the focus on the outsize contribution of meat production and especially beef.
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But much less is known about the implications of individual U.S. dietary choices on other environmental concerns, such as water scarcity.In a study scheduled for online publication April 15 in the journal Meat consumption is the top contributor to the water scarcity footprint of the average U.S. diet, accounting for 31% of the impacts, according to the study. And within the meat category, beef's contribution is about six times higher than chicken's.But other foods that require lots of water or that are mainly grown in U.S. regions where water is scarce -- including certain fruits, nuts and vegetables -- also have high water-scarcity footprints, the researchers say."Beef is the largest dietary contributor to the water scarcity footprint, as it is for the carbon footprint," said study lead author Martin Heller of the Center for Sustainable Systems at U-M's School for Environment and Sustainability."But the dominance of animal-based food is diminished somewhat in the water scarcity footprint, in part because the production of feed grains for animals is distributed throughout less water-scarce regions, whereas the production of vegetables, fruits and nuts is concentrated in water-scarce regions of the United States, namely the West Coast states and the arid Southwest."The novel U-M/Tulane approach combines the types and quantities of foods in the diets of individuals, the irrigation water required to produce those foods, and the relative scarcity of water where the irrigation occurs.The study also includes examples of dietary substitutions that consumers can make to reduce their personal water scarcity footprint. For example, they can:Replace some high water-intensity tree nuts (almonds, walnuts and cashews) with peanuts or seeds.Limit consumption of high water-intensity vegetables and replace them with lower-intensity vegetables such as fresh peas, Brussels sprouts, cabbage and kale.Replace some beef with other protein sources, such as chicken, pork, soybeans, dry edible beans, peanuts or sunflower seeds.The concept of the water scarcity footprint is akin to the more familiar carbon footprint, which estimates the greenhouse gas emissions produced by specific human activities, products and processes. One key difference: Greenhouse gas emissions boost levels of heat-trapping gases globally, while the impacts of dietary choices on water scarcity are mainly local.A handful of previous studies have looked at how variation in dietary choices influences water scarcity, but most of those studies relied on national-level dietary data. The new U-M/Tulane study, in contrast, links the water scarcity impacts of food production to the individual dietary choices of more than 16,000 Americans.Also, most previous studies do not recognize the impacts of regional differences in water scarcity, even though irrigation in the U.S. is highly regionalized, with 81% of the water use occurring in 17 Western states.The new analysis looked at the irrigation water demands of 160 crops, taking into account water scarcity conditions at the watershed level. Scarcity-weighted water consumption data were used to establish a water scarcity footprint for each crop.The individual crop footprints were then aggregated to the national level and linked to dietary-choice data from the federal National Health and Nutrition Examination Survey, which looked at the dietary choices of 16,800 Americans."Our approach is novel in that it links individual dietary choices with the water scarcity-weighted impact of irrigation for specific crops at the watershed level, thus offering insight into the distribution of impacts across a population," said study co-author Greg Keoleian, director of the Center for Sustainable Systems at U-M's School for Environment and Sustainability.To further investigate how dietary choices impact water scarcity, the researchers ranked all of the individual diets by their water scarcity footprint -- from lowest impact to highest impact -- then divided those diets into five equal groups, or quintiles.The diets of individuals in the highest-impact quintile accounted for 39% of the overall footprint -- a contribution 4.7 times greater than diets in the lowest quintile. Individuals in the top quintile consume large quantities of beef and higher-than-average amounts of tree nuts (almond, walnut, cashew) and high water-intensity fruits and vegetables such as lemon juice, avocado, asparagus, broccoli and cauliflower, according to the study."The water-use impacts of food production should be a key consideration of sustainable diets. But until now, little has been known about the water scarcity demands of diets -- especially the diets of individuals," said study co-author and overall project principal investigator Diego Rose of Tulane University."There is a lot of variation in the way people eat, so having a picture with this sort of granularity -- at the individual level -- enables a more nuanced understanding of potential policies and educational campaigns to promote sustainable diets."U-M's Heller said it's time to start thinking about the resource budgets -- measured in carbon, water and land -- of our foods and the costs associated with producing them."For water, part of that cost depends on the scarcity of the water where a food is grown," Heller said. "Budgeting the water scarcity footprint of our diet doesn't mean we need to eliminate the 'costly' foods completely, but it probably means we need to consume them sparingly."
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Agriculture & Food
| 2,021 |
April 14, 2021
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https://www.sciencedaily.com/releases/2021/04/210414154947.htm
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Of apples and oil pumpkins: News from microbiome research
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The extent to which the composition of the microbiome of apples and oil pumpkins depends on the geographical location and what insights can be derived from this for breeding, health and shelf life of the fruits is shown in two recent publications by researchers at TU Graz.
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We refer to the microbiome as the community of microorganisms that exist in or on all organisms, including bacteria and fungi. A team from the Institute of Environmental Biotechnology at Graz University of Technology (TU Graz) led by Institute head Gabriele Berg has now investigated the microbiomes of apples and oil pumpkins in two independent studies. The researchers have found that bacteria useful to plants are largely "inherited," i.e., passed on to the next generation, while the community of fungi in the microbiome is highly dependent on the particular soil microbiome and thus on the locality.The breeding of the Styrian oil pumpkin is relatively recent -- it started about 150 years ago and is well documented. Through selective breeding of resistant, increasingly tasty and high-yielding pumpkins, the seed microbiome of the oil pumpkin has changed over the generations. Using a well-documented breeding line, the environmental biotechnologists at TU Graz were able to demonstrate for the first time that the microorganisms on the seeds of the pumpkin are inherited and probably crucial for certain plant traits. Peter Kusstatscher, one of the study authors, explains: "We studied bacteria and fungi on oil pumpkin seeds and found that the plant passes on much of its bacteria on the seed -- up to 60 percent, in fact -- to the next generation, while fungal diversity on the seed depends largely on the local soil microbiome." Kusstatscher continues, "It's mainly microorganisms that are useful for the plants that are inherited. In this respect, the plant behaves in a similar way to humans: babies also get their microbiome from their mothers."The results published in Apples are among the most popular and widely consumed fruits in the world. Fruit quality, yield, and storability are important factors for fruit growers, fruit trade, and consumers. In a worldwide study, the apple of the variety "Royal Gala" was examined for the first time with regard to the composition and possible local differences of its microbiome. An international team was able to show that the nature and structure of the fungal and bacterial communities of the apple at the time of harvest vary from region to region, i.e. they are strongly dependent on the geographical location and thus on the prevailing climatic conditions and management practices. In particular, the fungal diversity of the fruit is significantly dependent on the locality and suggests a relationship to the type and frequency of post-harvest diseases. On the other hand, a continental pattern can be drawn especially for the bacterial community which indicates adaptation of the apple microbiome to local environments.Ahmed Abdelfattah, Marie Curie post-doctoral fellow at the Institute of Environmental Biotechnology at TU Graz and lead author of the study explains: "Despite the variations we observed in the apple microbiome, we were still able to identify a so-called 'core' microbiome i.e. members of the microbiome that are shared globally among the apples. This global 'core' microbiome is represented by several beneficial microbial indicators and makes up a large portion of the fruit's microbial community."Similar to the study results on oil pumpkin, this study lays another foundation for new approaches to improving fruit quality and health, in this case of apples. Furthermore, the results form the basis for investigations of complex microbial interactions on the surface of apple fruits. The study results were published in Environmental Microbiology.Both studies highlight the importance of the microbiome for health issues from the crop in the agro-ecosystem to humans who consume the food. At the same time, new avenues for microbiome management are opening up for environmentally friendly pest control.
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Agriculture & Food
| 2,021 |
April 12, 2021
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https://www.sciencedaily.com/releases/2021/04/210412142738.htm
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Unusual fossil reveals last meal of prehistoric pollinator
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An amber fossil of a Cretaceous beetle has shed some light on the diet of one of the earliest pollinators of flowering plants.
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The animal's remains were unearthed by researchers at the University of Bristol and the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) who were able to study its fossil faecal matter, which was composed solely of pollen.Besides being a visitor of angiosperms -- flowering plants -- researchers now have conclusive evidence that the new fossil named Pelretes vivificus also fed on their pollen. Details of this discovery have been published today in "The beetle is associated with clusters of pollen grains, suggesting that short-winged flower beetles visited angiosperms in the Cretaceous. Some aspects of the beetle's anatomy, such as its hairy abdomen, are also adaptations associated with pollination," said Professor Chenyang Cai, palaeontologist from the School of Earth Sciences and NIGPAS.Erik Tihelka, entomologist and palaeontologist at the School of Earth Sciences, added: "The fossil is associated with beetle coprolites -- fossil faecal pellets -- that provide a very unusual but important insight into the diet of short-winged flower beetles in the Cretaceous. The fossil faecal pellets are completely composed of pollen, the same type that is found in clusters surrounding the beetle and attached to its body. We thus know that Pelretes visited angiosperms to feed on their pollen. This finding provides a direct link between early flowering plants in the Cretaceous and their insect visitors; it shows that these insect fossils were not just incidentally co-preserved with pollen, but that there was a genuine biological association between the two."While pollinators such as bees and butterflies provide crucial ecosystem services today, little is known about the origin of the intimate association between flowering plants and insects.Cretaceous amber fossils provide an important source of evidence for understanding the biology of early angiosperms, before they became the dominant group of plants on Earth. Amber is the fossil resin of ancient trees that often fortuitously trapped insects and other small organisms, preserving them with life-like fidelity."Farmers who want to protect their orchards can set up sticky traps on trees to monitor insects. Now imagine if your only insight into an ancient ecosystem were such sticky traps and you were to reconstruct all its ecological interactions based solely on this source of evidence. That is the challenge faced by palaeontologists studying amber," explains Tihelka. "Luckily, the amber trap from northern Myanmar is one of the riches fossiliferous amber deposits known. Besides the unparalleled abundance of fossil insects, the amber dates back to the mid-Cretaceous, right when angiosperms were taking off," said Mr Tihelka.Two hundred million years ago the world was as green as today, overgrown with dense vegetation. But it was not as colourful -- there were no flowers. Flowering plants that make up over 80% of all plant species today, only begun to diversify in the Cretaceous, about 125 million years ago. Some scientists have attributed the huge evolutionary success of angiosperms to their mutualistic relationships with insect pollinators, but fossil evidence of Cretaceous pollinators has so far been scarce.The flower beetle Pelretes vivificus lived in the Burmese amber rainforest some 98 million years ago. Its closest relatives are short-winged flower beetles (Kateretidae) that today occur in Australia, visiting a diverse range of flowers and feeding on their pollen."The pollen associated with the beetle can be assigned to the fossil genus Tricolpopollenites. This group is attributed to the eudicots, a living group of angiosperms, that includes the orders Malpighiales and Ericales," explains Dr. Liqin Li, fossil pollen specialist from NIGPAS who contributed to the study.This shows that pollinators took advantage of early angiosperms soon after their initial diversification and by the mid-Cretaceous visited a diverse range of groups.
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Agriculture & Food
| 2,021 |
April 12, 2021
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https://www.sciencedaily.com/releases/2021/04/210412114855.htm
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For tomato genes, one plus one doesn't always make two
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Both people and tomatoes come in different shapes and sizes. That is because every individual has a unique set of genetic variations -- mutations -- that affect how genes act and function. Added together, millions of small genetic variations make it hard to predict how a particular mutation will impact any individual. Cold Spring Harbor Laboratory (CSHL) Professor and Howard Hughes Medical Institute Investigator Zach Lippman showed how genetic variations in tomatoes can influence the way a specific mutation affects the plant. He is working toward being able to predict the effects of mutations on different tomato varieties.
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In this study, Lippman and his team used CRISPR, a highly accurate and targeted gene-editing tool, on two tomato genes that control fruit size, SlCV3 and SlWUS. They generated over 60 tomato mutants by removing little pieces of DNA in the promoter regions, areas near the genes that control their expression. In some cases, individual mutations increased the size of the tomatoes by a little bit. Some pairs of mutations did not change fruit size at all. A few synergistic combinations caused a dramatic, unpredicted increase in fruit size. Lippman says:"The real Holy Grail in all this for crop breeding is predictability. If I mutate this sequence, I'm going to get this effect. Because there is this sea of other variants that nature has accumulated nearby the mutation that you're engineering, as well as scattered throughout the genome, many of which could be influencing the specific mutation that you're creating."This range of interactions for any two mutations models the consequences of a single mutation occurring in different genetic backgrounds. The effect is comparable to those found in some human diseases, where some people might have certain pre-existing mutations that protect them from disease-causing mutations.Lippman and his team will continue quantifying how individual and combined mutations affect certain crop traits. So far, they have measured interactions between two individual mutations, but genomes have millions of variations. Lippman hopes to study enough measurable interactions to make breeding more predictable and efficient.
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Agriculture & Food
| 2,021 |
April 12, 2021
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https://www.sciencedaily.com/releases/2021/04/210412114850.htm
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Feces core records 4,300 years of bat diet and environment
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Deep in a Jamaican cave is a treasure trove of bat feces, deposited in sequential layers by generations of bats over 4,300 years.
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Analogous to records of the past found in layers of lake mud and Antarctic ice, the guano pile is roughly the height of a tall man (2 meters), largely undisturbed, and holds information about changes in climate and how the bats' food sources shifted over the millennia, according to a new study."We study natural archives and reconstruct natural histories, mostly from lake sediments. This is the first time scientists have interpreted past bat diets, to our knowledge," said Jules Blais, a limnologist at the University of Ottawa and an author of the new study in Blais and his colleagues applied the same techniques used for lake sediments to a guano deposit found in Home Away from Home Cave, Jamaica, extracting a vertical "core" extending from the top of the pile to the oldest deposits at the bottom and taking it to the lab for biochemical analysis.About 5,000 bats from five species currently use the cave as daytime shelter, according to the researchers."Like we see worldwide in lake sediments, the guano deposit was recording history in clear layers. It wasn't all mixed up," Blais said. "It's a huge, continuous deposit, with radiocarbon dates going back 4,300 years in the oldest bottom layers."The new study looked at biochemical markers of diet called sterols, a family of sturdy chemicals made by plant and animal cells that are part of the food bats and other animals eat. Cholesterol, for example, is a well-known sterol made by animals. Plants make their own distinctive sterols. These sterol markers pass though the digestive system into excrement and can be preserved for thousands of years."As a piece of work showing what you can do with poo, this study breaks new ground," said Michael Bird, a researcher in environmental change in the tropics at James Cook University in Queensland, Australia, who was not involved in the new study. "They really extended the toolkit that can be used on guano deposits around the world."Like sediment and ice core records, the guano core extracted from the Jamaican cave recorded the chemical signatures of human activities like nuclear testing and leaded gasoline combustion, which, along with radiocarbon dating, helped the researchers to correlate the history seen in the guano with other events in Earth's climate history.Bats pollinate plants, suppress insects and spread seeds while foraging for food. Shifts in bat diet or species representation in response to climate can have reverberating effects on ecosystems and agricultural systems."We inferred from our results that past climate has had an effect on the bats. Given the current changes in climate, we expect to see changes in how bats interact with the environment," said Lauren Gallant, a researcher at the University of Ottawa and an author of the new study. "That could have consequences for ecosystems."The new study compared the relative amounts of plant and animal sterols in the guano core moving back in time though the layers of guano to learn about how bat species as a group shifted their exploitation of different food sources in the past.The research team, which included bat biologists and a local caving expert, also followed living bats in Belize, tracking their food consumption and elimination to gain a baseline for the kinds of sterols that pass through to the feces when bats dine on different food groups.Plant sterols spiked compared to animal sterols about 1,000 years ago during the Medieval Warm Period (900-1,300 CE), the new study found, a time when cores of lakebed sediments in Central America suggest the climate in the Americas was unusually dry. A similar spike occurred 3,000 years ago, at a time known as the Minoan Warm Period (1350 BCE)."Drier conditions tend to be bad for insects," Blais said. "We surmised that fruit diets were favored during dry periods."The study also found changes in the carbon composition of the guano that likely reflect the arrival of sugarcane in Jamaica in the fifteenth century."It's remarkable they can find biochemical markers that still contain information 4,000 years later," Bird said. "In the tropics, everything breaks down fast."The approach demonstrated in the new study could be used to glean ecological information from guano deposits around the world, even those only a few hundred years old, Bird said."Quite often there are no lakes around, and the guano provides a good option for information about the past. It also contains biological information that lakes don't." Bird said. "There's a lot more work to do and a lot more caves out there."
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Agriculture & Food
| 2,021 |
April 12, 2021
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https://www.sciencedaily.com/releases/2021/04/210412114808.htm
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Keeping livestock: Can we end the cage age?
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Between 2018 and 2020, 1,4 million EU citizens signed the petition 'End the Cage Age', with the aim of ending cage housing for farm animals in Europe. In response to this citizens initiative, the European Parliament requested a study by Utrecht University researchers on the possibilities to end cage housing. On 13 April, the scientists will present their report 'End the Cage Age -- Looking for Alternatives' to the European Parliament.
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In the report, behavioural biologists, animal scientists, veterinarians and ethicists from Utrecht University's Faculty of Veterinary Medicine analysed the available scientific literature on alternatives to cage housing. "Our focus was on laying hens and pigs" says Bas Rodenburg, Professor of Animal Welfare at Utrecht University. "Because these are the species that are kept in the largest numbers, and cage-free alternatives are already available or in development for them." For other species -- such as dairy and veal calves and rabbits -- the researchers give a brief overview of the current situation and possibilities."Our report shows that ending cage housing has positive effects on the behaviour and welfare of animals," Rodenburg says. "This is because animals in cage-free alternatives can exhibit their natural behaviour. Chickens and pigs are omnivores; they are normally foraging, rooting and pecking all day long. This behaviour is essential for these animals, but they need materials to rummage around in, such as sand, straw or wood shavings. That is difficult or impossible to achieve in cages."Regarding sustainability, no large differences in environmental, social and economic impact between cage housing and cage-free alternatives were found in studies published to date. However, the alternatives do pose new risks. For example a higher risk of infectious diseases and social unrest, like feather pecking. To successfully switch to cage-free alternatives, farmers must therefore be trained and learn to work with the new systems.For some species, like mink or geese and ducks for the production of foie gras, there is no cage-free alternative. The proposed alternative would therefore be a ban on production and a European import ban.The study shows that the switch to cage-free alternatives is possible. But how can this actually be achieved? "It has to be made attractive for farmers to make the switch," answers Rodenburg. "The required investments must result in added value for their products. And consumers must be prepared to pay a little more for this, so awareness is also needed among this group."In the short term, this calls for financial measures such as subsidies for new welfare-friendly systems and welfare labels on products, enabling consumers to shop more consciously. In the longer term, legislation could prohibit certain types of cage housing. Rodenburg: "One of our most important recommendations is to involve all stakeholders in the process, so they can design the new and improved livestock farming together."On Tuesday 13 April at 13:45 CET, two researchers from Utrecht University will present the report 'End the Cage Age -- Looking for Alternatives' to the European Parliament: Bas Rodenburg, professor of Animal Welfare at Utrecht University, and Maite van Gerwen, project manager of the Centre for Sustainable Animal Stewardship at Utrecht University.The petition itself will be debated in parliament on 15 April.
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Agriculture & Food
| 2,021 |
April 8, 2021
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https://www.sciencedaily.com/releases/2021/04/210408165659.htm
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Could Mario Kart teach us how to reduce world poverty and improve sustainability?
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Many Mario Kart enthusiasts are familiar with the rush of racing down Rainbow Road, barely squeaking around a corner, and catching a power-up from one of the floating square icons on the screen -- or, less ideally, slipping on a banana peel laid by another racer and flying off the side of the road into oblivion. This heated competition between multiple players, who use a variety of game tokens and tools to speed ahead or thwart their competitors, is part of what makes the classic Nintendo racing game that has been around since the early 1990s so appealing.
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"It's been fun since I was a kid, it's fun for my kids, in part because anyone can play it," says Andrew Bell, a Boston University College of Arts & Sciences assistant professor of earth and environment. But as a researcher studying economic principles, Bell also sees Mario Kart as much more than just a racing game.In a recent paper, Bell argues that the principles of Mario Kart -- especially the parts of it that make it so addictive and fun for players -- can serve as a helpful guide to create more equitable social and economic programs that would better serve farmers in low-resource, rural regions of the developing world. That's because, even when you're doing horribly in Mario Kart -- flying off the side of Rainbow Road, for example -- the game is designed to keep you in the race."Farming is an awful thing to have to do if you don't want to be a farmer," Bell says. "You have to be an entrepreneur, you have to be an agronomist, put in a bunch of labor...and in so many parts of the world people are farmers because their parents are farmers and those are the assets and options they had." This is a common story that Bell has come across many times during research trips to Pakistan, Bangladesh, Cambodia, Malawi, and other countries in southern Africa, and is what largely inspired him to focus his research on policies that could aid in development.In his new paper, Bell argues that policies that directly provide assistance to farmers in the world's poorest developing regions could help reduce poverty overall, while increasing sustainable and environmentally friendly practices. Bell says the idea is a lot like the way that Mario Kart gives players falling behind in the race the best power-ups, designed to bump them towards the front of the pack and keep them in the race. Meanwhile, faster players in the front don't get these same boosts, and instead typically get weaker powers, such as banana peels to trip up a racer behind them or an ink splat to disrupt the other players' screens. This boosting principle is called "rubber banding," and it's what keeps the game fun and interesting, Bell says, since there is always a chance for you to get ahead."And that's exactly what we want to do in development," he says. "And it is really, really difficult to do."In the video game world, rubber banding is simple, since there are no real-world obstacles. But in the real world, the concept of rubber banding to extend financial resources to agricultural families and communities who need it the most is extremely complicated.Those opportunities might look like this, Bell says: governments could set up a program so that a third party -- such as a hydropower company -- would pay farmers to adopt agricultural practices to help prevent erosion, so that the company can build a dam to provide electricity. It is a complicated transaction that has worked under very specific circumstances, Bell says, but systems like this -- known as Payments for Ecosystem Services (PES) -- have been successful in benefitting both the farmers and the environment. A major challenge is finding private companies that are willing to pay for ecosystem services, and connecting them with farmers who are willing to change their agricultural practices. The good news about rubber banding, though, is that the more people participate in such economic programs, the more other people will join in as well; a concept Bell calls "crowding in," in his analysis.Bell says the biggest obstacle to overcome in most of the world's developing places is figuring out how to route assistance to people in need in the first place -- because, until recently, many of the people were essentially living off the grid."It's hard to know who is in the back [of the pack]," Bell says.But Bell says the ability to reach people in the lowest-resource areas has improved in the last decade or so, largely thanks to the adoption of mobile phones. (In another recent paper, Bell and his collaborators found that smartphones can also play a role in understanding and addressing food insecurity.) Now, mobile devices help local governments and organizations identify people searching for more prosperous livelihoods beyond the challenging practice of agriculture and reach out to those people with economic opportunities.Bell says further expanding access to mobile devices in poor regions of the world would also allow the gap between the richest and poorest families to be better calculated, and could also help measure the success of newly implemented policies and programs."Mario Kart's rubber banding ethos is to target those in the back with the items that best help them to close their gap -- their own 'golden mushrooms,'" Bell wrote in the paper, referring to the power-up that gives lagging racers powerful speed bursts. Improving environmental stewardship while alleviating poverty requires that researchers and decision-makers consider from the outset, "within their unique context and challenge at-large, what the golden mushroom might be."
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Agriculture & Food
| 2,021 |
April 8, 2021
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https://www.sciencedaily.com/releases/2021/04/210408131450.htm
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Introduced honeybee may pose threat to native bees
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A Curtin University study has found the introduced European honeybee could lead to native bee population decline or extinction when colonies compete for the same nectar and pollen sources in urban gardens and areas of bush.
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Published in the Under these conditions, it would appear that European honeybees, being very abundant, and effective foragers, with the ability to exploit a wide range of flowers, can outcompete native bees for nectar and pollen resources.Lead author, Forrest Foundation Scholar Miss Kit Prendergast, from Curtin's School of Molecular and Life Sciences said the research was conducted over two years in urban gardens and areas of native vegetation on the Swan Coastal Plain at Perth, Western Australia and revealed a complex relationship between native and introduced bees."Not all native bee species were impacted, but when native bees preferred many of the same flower species as honeybees or were of larger body size, meaning they needed more food, this was when honeybees had a negative impact on native bees," Miss Prendergast said."This occurs due to resource competition, where honeybees were more successful at exploiting food resources from flowers, leaving not enough nectar and pollen to support native bee populations.Unlike native bees, honeybees occur in colonies of tens of thousands of individuals, and are better at telling other colony members where flower patches are. This communication is done by using a combination of movement and vibrations known as the "waggle dance" and using scent."Competition from honeybees was particularly fierce in residential gardens where there are lower proportions of the native wildflowers that our native bees have co-evolved to forage on," Miss Prendergast said."This impact of competition with a super-abundant, domesticated and feral introduced bee, when combined with pressures from habitat loss as a result of increasing urbanisation and agriculture, especially livestock agriculture, places some native bee species at risk of becoming endangered or even extinct."Miss Prendergast said planting more flowering plants, particularly those preferred by vulnerable species of native bees, could help prevent them from declining in number. Controlling the density of honeybees would also be critical in reducing the pressure on vulnerable native bees."Native bees are an integral and important part of any ecosystem, including in the Southwest Australian biodiversity hotspot in which our research was conducted," Miss Prendergast said."European honeybees have been introduced around the world and pose an added threat to many native bee species already at risk of declining numbers or even extinction due to increasing urbanisation."
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Agriculture & Food
| 2,021 |
April 7, 2021
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https://www.sciencedaily.com/releases/2021/04/210407124013.htm
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Red deer have personality and it is related to their dominance behavior
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An international team of researchers has studied individual differences in the behaviour of red deer. They found that several observed behaviours form a personality component, which they labelled "Confidence/Aggressiveness."
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As is commonly known, individual people behave consistently different from each other and these kinds of consistent differences in behaviour are called personality. Studies on species other than humans, from insects to elephants, have found that personalities are widespread in nature.The team consists of researchers from the Czech University of Life Sciences Prague, the University of South Bohemia, Czech Republic, the University of Vienna, Austria, and the University of Turku, Finland and is led by Bruno Esattore from the Department of Ethology at the Institute of Animal Science in Prague. The team of researchers studied personality of red deer with a newly developed questionnaire, as well as observed their behaviours.The researchers identified a single personality component related to Confidence/Aggressiveness. Interestingly, some of the behaviours making up this component were linked with dominance behaviour in red deer. The study has just been published in - Many personality studies have focused on primates, rodents, birds, field crickets or fish. Despite of their well-studied biology and increasing popularity in the farming sector, the personality structure of one of Europe's most iconic mammals, the red deer, has until now been unknown, says the lead author of the study Bruno Esattore.The personality data were collected by using a novel questionnaire for which experienced observers rated 15 behaviours on a scale from 1 to 5, with 1 meaning the deer shows this behaviour "Almost never" and 5 meaning "Most of the time."- We think it is extremely interesting that inter-individual differences which have been so far overlooked or even regarded as distracting are those that eventually make the difference when trying to identify the personality of these animals, states Doctoral Candidate Laura Saggiomo from the Faculty of Forestry and Wood Sciences of the Czech University of Life Sciences Prague.- These findings are exciting, but of course, they are not the final picture of how personality manifests in red deer, says Postdoctoral Researcher Vedrana Šlipogor from the Department of Zoology of the University of South Bohemia in Budweiss, Czech Republic.The team put lots of care into the making of the questionnaire, however, for a majority of the 15 behaviours the observers did not agree very well on their ratings of the deer.- This was an unexpected result and shows that we have to be careful with our behavioural descriptions and to consider observer perceptions when using questionnaire ratings of animal behaviour for scientific studies, Šlipogor further states.The team then linked these findings with observations of the dominance interactions of the male deer in their bachelor groups.- We found no relationship between deer's dominance and personality, but dominance was related to some of the rated behaviours, showing our personality questionnaire captured some biologically meaningful variation, says Bruno Esattore.Studies on animals kept in zoos or different facilities or farms have shown that knowing the individual characteristics or personalities of animals can help to implement the best strategy in guaranteeing their welfare.- Personality has not been largely considered in welfare management decisions, but lately it is receiving more and more attention. We believe that studies like ours can help to add to the improvement of animal management and welfare, concludes Martin Seltmann from the Department of Biology at the University of Turku.
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Agriculture & Food
| 2,021 |
April 6, 2021
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https://www.sciencedaily.com/releases/2021/04/210406120717.htm
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Rising Sika deer populations linked to bovine TB infections
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New research suggests Ireland's increasing populations of Sika deer may be linked to local outbreaks of TB infection in cattle.
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Although TB infection rates have decreased in general in recent decades, county-level data shows a correlation between higher Sika numbers and higher local TB infections -- with County Wicklow a particular hotspot.The research, conducted by researchers from Trinity College Dublin and the National Parks and Wildlife Service and supported by the Department of Agriculture, Food and the Marine, has major implications for controlling TB. It has just been published in the journal, First author of the journal article, Dr David Kelly, from Trinity's School of Natural Sciences, said:"Irish farmers have been aware of the effects of bovine TB for well over 70 years. Its incidence has steadily diminished in Ireland, from 3% in 1960 to 0.3% some 50 years later. In the mid-1980s it became clear European badgers were a TB wildlife host. Since then, badger populations have been controlled around farms with TB outbreaks whenever those outbreaks cannot be linked to cattle.In recent years, however, it has become clear that controlling TB in badger populations cannot rely on culling alone. Along with this change in thinking, there has been a steady shift away from culling and towards badger vaccination. Unfortunately, while the management of one TB wildlife host has made great advances, another wildlife TB host has appeared on the radar: deer."The number of deer in Ireland has been rising steadily during the 21st century, and studies in Europe and the USA have shown that deer, at higher densities, can sustain TB in their herds. Indeed, recent research has identified Sika deer in County Wicklow as one such maintenance host of TB.The researchers behind the current study used county-level population densities (taken between 2000 and 2018) to track the three known maintenance hosts of TB in Ireland: cattle, badgers, and Sika deer.They then considered how variations in local densities compared with the variation in bovine TB infection across the country (and also at county-level).Dr Kelly said:"Our analyses show that while there have been general reductions in TB infection, there is a correlation between increasing Sika deer density and higher local TB infection. This pattern has emerged in recent years and has major implications for TB control within Ireland."Now, when attempting to manage TB in wildlife, Sika deer will need to be considered as well as badgers. Our analyses suggest Sika deer are currently of greatest concern in County Wicklow but if numbers continue to rise in other counties they may also pose problems elsewhere."
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Agriculture & Food
| 2,021 |
April 2, 2021
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https://www.sciencedaily.com/releases/2021/04/210402141739.htm
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Science has not kept pace with aquaculture
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Aquaculture -- the farming of fish, shellfish, and other aquatic animals for food -- has reached unprecedented levels of growth in recent years, but largely without consideration of its impact on individual animals, finds a new analysis by a team of researchers.
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"The scale of modern aquaculture is immense and still growing," says Becca Franks, a research scientist at New York University's Department of Environmental Studies and the lead author of the paper, which appears in the journal The study is the first to systematically examine the scientific knowledge about animal welfare for the 408 aquatic animal species being farmed around the world -- animals that include salmon, carp, and shrimp. The researchers found that specialized scientific studies about animal welfare -- generally defined as an animal's ability to cope with its environment -- were available for just 84 species. The remaining 324 species, which represent the majority of aquaculture production, had no information available.Animal welfare legislation is not new, but in recent years, governments have adopted laws aimed at enhancing enforcement and extending animal protections.With traditional fishing on the decline, aquaculture has been touted as both a solution to food insecurity and as a means to reduce pressure on species in seas and oceans. However, the growth of aquaculture, or aquafarming, hasn't diminished stress on wild populations. Meanwhile, as recently as 2018, 250 to 408 billion individual animals from more than 400 species were farmed in aquaculture -- or about 20 times the number of species farmed in animal agriculture on land -- according to the United Nations' Food and Agriculture Organization.The expansion of aquaculture raises concerns that the industry is moving ahead without sufficient knowledge of the animal life it is growing. The absence of this information signals risk because its operations and decisions are not scientifically based, the researchers note, and can lead to poor living conditions and suffering for the individual animals involved.To explore this matter, the team, which also included Jennifer Jacquet, an associate professor in NYU's Department of Environmental Studies, and Chris Ewell, an NYU undergraduate at the time of the study, sought to determine what research literature existed on the more than 400 species being farmed in 2018.Their results showed that only 25 species, or about 7 percent of animals being farmed in aquaculture, had five or more publications on these animals' welfare. By contrast, 231 species had no welfare publications while 59 had only one to four such publications. The remaining 93 did not have species-level taxonomic information, meaning it lacked sufficiently detailed findings on these species."While the presence of animal welfare knowledge does not ensure well-being, the absence of such information is troubling," says Franks. "In sum, our research reveals that modern aquaculture poses unparalleled animal welfare threats in terms of the global scope and the number of individual animal lives affected."The authors emphasize that some aquatic animal species, such as bivalves, which include oysters and clams, may present fewer welfare concerns to begin with and may be a more promising avenue for production."Although aquaculture has been around for thousands of years, its current expansion is unprecedented and is posing great risks, but, because it is so new, we can choose a different path forward," Franks says.
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Agriculture & Food
| 2,021 |
April 2, 2021
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https://www.sciencedaily.com/releases/2021/04/210402135504.htm
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Serving size, satisfaction influence food waste on campus
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Understanding what drives food choices can help high-volume food service operations like universities reduce waste, according to a new study.
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Researchers have concluded that food waste in places like university cafeterias is driven by how much people put on their plates, how familiar they are with what's on the menu and how much they like -- or don't like -- what they're served.Food waste has been studied often in households, but not so often in institutional settings like university dining commons. What drives food choices in these "all-you-care-to-eat" facilities is different because diners don't perceive personal financial penalty if they leave food on their plates.Published in the journal Co-author Eleanor Putnam-Farr, assistant marketing professor at Rice's Jones Graduate School of Business, is available to discuss the findings and potential impact with news media.The researchers conducted student surveys during the 2019 spring and fall semesters to study foods types, diner confidence and diner satisfaction. They used photos taken by diners themselves before and after eating to measure how much food was taken and how much of it went to waste. "Diners were intercepted at their dining halls and asked if they wanted to participate in a study about food choices and satisfaction, but the objective of investigating food waste behavior was not disclosed," the authors wrote.The study found the amount of food wasted didn't significantly differ among types of food. Instead, researchers discovered waste was related to the amount of food diners put on their plates, how satisfied they were with their meals and how often they went to the dining commons. If students were satisfied with their food, they tended waste less of it. And diners who visited the commons most often -- making them more familiar with the menus and more confident in their choices -- tended to waste less.Mixed dishes, like sandwiches or stir-fry, took up a greater percentage of the surface area on surveyed plates than animal proteins or grains and starches. Those three types of food took up a greater area of the plates than fruits, vegetables or plant proteins. The amount of food wasted, however, did not significantly differ among the various food categories.The mixed dishes and animal proteins that took up greater portions of the plate tended to be pre-plated by the commons staff or have a suggested serving size. The study's results showed that greater amounts of food taken by diners correlated with the item being pre-plated or served by others.The authors recommend future research on the topic uses their multicampus approach -- which enabled them to study food choice among a large and diverse group -- to better understand what causes food waste and find out if it can be reduced by interventions such as posting signs that encourage healthier choices.
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Agriculture & Food
| 2,021 |
April 2, 2021
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https://www.sciencedaily.com/releases/2021/04/210402114057.htm
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Lanternfly's attraction to vertical silhouettes could help monitor, trap it
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Like moths to a flame, spotted lanternflies are visually drawn toward and seemingly captivated by vertical objects such as utility poles, a behavior that could be valuable in predicting where the pests might be heading, according to entomologists in Penn State's College of Agricultural Sciences.
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Research from the laboratory of Tom Baker, recently published in the These findings show that telephone poles attract flight-dispersing spotted lanternflies, which are visually drawn to turn and land on the poles when they are less than about 10 feet away. They remain on the pole for many minutes, even hours, while crawling up toward the top to try to take flight again.However, a large proportion of those launching themselves from the pole are drawn back to the pole, which serves as a sort of "visual magnet" from which the insects cannot escape for a while. The pole thus attracts and retains a large proportion of the lanternflies that are drawn to it."The spotted lanternfly feeds on more than 70 plant species, making it a great concern to U.S. tree-fruit and grape growers, as well as to the forest products industry," said Baker, distinguished professor of entomology and chemical ecology."Understanding the how and why of its flight capabilities and its attraction to stimuli from the environment can help us better exploit these behaviors to assess, and possibly thwart, future threats from this pest."This latest study is an offshoot of experiments on the insect's flight behaviors and dispersal patterns led by Baker and his colleagues Andrew Myrick, assistant research professor of entomology, and Michael Wolfin, postdoctoral research associate.Their flight-dispersal research efforts began during late summer and early fall in September and October of 2017 and 2018 at a fruit farm near Oley and at Dorney Park in Allentown. Both locations had been severely affected by spotted lanternfly infestations.Baker's team had found that, in the lanternflies' apparent quest to find new sources of food to complete their development and then mate, they will fly onto and crawl to the top of the nearest vertical surfaces -- including inanimate objects such as buildings and telephone poles and host and nonhost plants -- and launch themselves into the wind.Because lanternflies cannot generate much lift, only thrust, their normal flight paths conform to gradually descending, straight-line trajectories in which they are able to traverse usually only 30 to 150 feet over the ground before landing.Baker reported that their landing sites are indiscriminate with respect to species of trees, bushes and inanimate objects. "The lanternflies' forced landings on the ground due to insufficient lift are indiscriminate, too," he said.An exception to the typical low-to-the-ground flights occurs on days with high temperatures and rising air currents, allowing the low-flying lanternflies to be lifted to higher altitudes, with the now high-flying adults being transported downwind for perhaps thousands of yards.It is on such occasional late-summer days during the past few years when huge swarms have been deposited by the tens of thousands -- much to the alarm of the human population -- in shopping center parking lots, gas stations, and industrial and residential areas within heavily infested regions, Baker pointed out.However, he said that the pest's typical, low-to-ground flight coupled with its visual attraction to tall vertical objects may provide an effective and inexpensive way to monitor and even trap the insect."Telephone poles, which are plentiful and visible from the roadway, could be used by field scouts to document the presence or absence of spotted lanternfly by driving along and examining the poles at designated intervals," said Baker, who also suggested the possible use of poles as "attract-and-kill stations" to protect designated areas.Despite the importance of these natural flight-dispersal abilities, a method of travel for the lanternflies that citizens should be very concerned about is human transport of adults and egg masses via trains, trucks and recreational vehicles, noted Baker."People who are traveling through, or residing in, an area affected by spotted lanternfly should check their vehicles and items they are transporting before leaving to ensure they are not carrying these unwanted hitchhikers to new locations," he said.Yanchen Wang, former visiting doctoral student from Northeast Forestry University in Harbin, China, also contributed to the study, which received funding from the U.S. Department of Agriculture's Animal and Plant Health Inspection Service.
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Agriculture & Food
| 2,021 |
March 31, 2021
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https://www.sciencedaily.com/releases/2021/03/210331103535.htm
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Dairy cattle: What are we breeding for, and who decides?
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In an article appearing in the
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Genetic selection has been an extremely efficacious tool for the long-term enhancement of livestock populations, and the implementation of genomic selection has doubled the rate of gain in dairy cattle. Data captured through the national dairy herd improvement program are used to calculate genomic evaluations for comparing and ranking animals for selection. Over time, most of the focus on the selection indices used to rank bulls and cows on their genetic merit has changed from yield traits to fertility, health, and fitness traits.Today, most breeding stock are selected and marketed using the net merit dollars (NM$) selection index, which progressed from two traits in 1926 (milk and fat yield) to a mix of 36 individual traits following the most recent update three years ago. Updates to the index depend upon the estimation of a variety of values, and it can be challenging to reach an agreement among stakeholders on what should be included in the index at each review and how those traits should be weighted. Phenotypes for some of the new traits are difficult or costly to measure or depend upon changes to on-farm practices that have not been widely implemented. There is also a need to collect more comprehensive data about the environment in which animals perform, including information about feeding, housing, milking systems, and infectious and parasitic load."The rate of change is rapid, and farmers need objective sources of information more than ever before," said first author John B. Cole, PhD, affiliated with the Animal Genomics and Improvement Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD, USA, at the time the review was accepted for publication. "The best way for the industry to meet the needs of the dairy producers, who drive the whole system, is to treat genetic evaluations as a shared good for the benefit of all."The number of traits evaluated continues to increase, and is mind-boggling to many, which indicates that new approaches to classify and express traits may be necessary.
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Agriculture & Food
| 2,021 |
March 31, 2021
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https://www.sciencedaily.com/releases/2021/03/210331085900.htm
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Decellularized spinach serves as an edible platform for laboratory-grown meat
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Spinach, a cost-efficient and environmentally friendly scaffold, provided an edible platform upon which a team of researchers led by a Boston College engineer has grown meat cells, an advance that may accelerate the development of cultured meat, according to a new report in the advance online edition of the journal
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Stripped of all but its veiny skeleton, the circulatory network of a spinach leaf successfully served as an edible substrate upon which the researchers grew bovine animal protein, said Boston College Professor of Engineering Glenn Gaudette, the lead author of the new study. The results may help increase the production of cellular agriculture products to meet rising demand and reduce environmental costs."Cellular agriculture has the potential to produce meat that replicates the structure of traditionally grown meat while minimizing the land and water requirements," said Gaudette, the inaugural chair of BC's new Engineering Department. "We demonstrate that decellularizing spinach leaves can be used as an edible scaffold to grow bovine muscle cells as they develop into meat."Earlier advances by Gaudette in this area garnered worldwide attention. In 2017, Gaudette and a multi-university team showed that human heart tissue could be cultivated on a spinach leaf scaffold, which was chosen because it offered a natural circulatory system that is nearly impossible to replicate with available scientific tools and techniques."In our previous work, we demonstrated that spinach leaves could be used to create heart muscle patches," said Gaudette. "Instead of using spinach to regrow replacement human parts, this latest project demonstrates that we can use spinach to grow meat."Gaudette said the team, which included Worcester Polytechnic Institute graduate students Jordan Jones and Alex Rebello, removed the plant cells from the spinach leaf and used the remaining vascular framework to grow isolated cow precursor meat cells. The cells remained viable for up to 14 days and differentiated into muscle mass."We need environmentally and ethically friendly ways to grow meat in order to feed the growing population," said Gaudette, whose research is supported by New Harvest. "We set out to see if we can use an edible scaffold to accomplish this. Muscle cells are anchorage dependent, meaning they need to grab on to something in order to grow. In the lab, we can use plastic tissue culture plates, but plastic is not edible."The researchers point out that the successful results will lead to further characterization of the materials and scientific processes to better understand how to meet consumer demand and gauge how large-scale production could be accomplished in accordance with health and safety guidelines."We need to scale this up by growing more cells on the leaves to create a thicker steak," said Guadette. "In addition, we are looking at other vegetables and other animal and fish cells."
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Agriculture & Food
| 2,021 |
March 29, 2021
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https://www.sciencedaily.com/releases/2021/03/210329122823.htm
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Plants remember drought
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During drought, plants use a signalling molecule known from animals to limit their water loss. The molecule provides them with a kind of memory of how dry the day was.
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"I've been studying how plants regulate their water balance for over 35 years. To find a completely new and unexpected way for saving water has certainly been one of the most surprising discoveries in my life." So says Professor Rainer Hedrich, plant scientist and biophysicist from Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany.Hedrich's group discovered this new strategy together with researchers from the University of Adelaide in Australia. The results have been published in the journal The publication shows: plants use the signalling molecule GABA (gamma-aminobutyric acid) to remember the dryness of a day. The drier it is, the more GABA accumulates in the plant tissue during the day. And the next morning, the amount of GABA determines how wide the plant opens its leaf pores. The opening width of these pores can limit water loss.GABA is a signalling molecule that also occurs in humans and animals: there it is a messenger substance of the nervous system. Plants have no nerve cells and no brain. And yet GABA is now also found in them in connection with memory-like processes.Rainer Hedrich names another connection: Short-term memory, which the carnivorous Venus flytrap uses to count the number of times its prey touches it, depends on the calcium level in the cell. And it is the calcium level that regulates the enzymatic biosynthesis of GABA in plants.The GABA effect has been demonstrated in various crops, as Professor Matthew Gilliham of the University of Adelaide explains: "Under the influence of GABA, barley, broad beans and soybeans, for example, close their leaf pores." Laboratory plants that produce more GABA due to mutations also react in this way. In experiments, these mutants need less water and survive drought longer.Scientists know of other signalling substances in plants that cause the leaf pores to close. But GABA relies on a completely different mechanism of action, explains the lead author of the publication, Dr Bo Xu from the Australian Research Council Centre of Excellence in Plant Energy Biology.Insights into the water-saving mechanisms and drought tolerance of plants are becoming increasingly important in times of climate change. For some years now, increasing heat and drought have been affecting many crops. The earth's water resources that can be used for agriculture are also threatened. Mankind is therefore likely to be increasingly dependent on new varieties that still produce good yields with as little water as possible.
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Agriculture & Food
| 2,021 |
March 29, 2021
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https://www.sciencedaily.com/releases/2021/03/210329122809.htm
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Pioneering pollinator study offers clues to Darwin's 'abominable mystery'
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Research into the flower preferences of pollinating moths may have delivered a vital clue to the simple factors needed for the emergence of new species.
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Strong coevolutionary relationships between plants and animal pollinators have long been recognised as a potential driver of high rates of speciation in the 275,000 extant flowering plants.Shifts between pollinators, such as bumblebees, hummingbirds, hawkmoths and bats, often coincide with plant speciation events.Each of these pollinator "guilds" is attracted by a different set of floral traits such as colour, patterns, scent, shape, and nectar reward, collectively known as a pollination syndrome.So far, the detailed genetics of traits involved in pollinator shift-driven speciation remain unclear except in a few developing model systems.In a new study researchers set out to engineer a pollinator switch in the lab that could mirror the origin of a new species in nature.They selected a species in the genus Mimulus (monkeyflowers) section Erythranthe where the evolution of hawkmoth pollination from hummingbird pollinated ancestors has not occurred.They made genetic changes to two flower colour genes -- effectively synthesising a new Mimulus species with lower levels of the red pigment anthocyanin and yellow carotenoid pigments. These changes were based on observations in nature that most hummingbird-pollinated flowers are red and not easily visible to hawkmoths whose visual sensitivity does not extend to longer, red-light wavelengths. Hawkmoth-pollinated flowers, in contrast, are usually white or pale and highly reflective, adapted for detection by the crepuscular and nocturnal hawkmoths.Researchers tested the attractiveness of the four resulting colour phenotypes -- red, yellow, pink and white -- using lab-reared hawkmoths with no previous exposure to flowers.Hawkmoths strongly preferred "derived" non-red colours -- yellow, pink, and white -- over the ancestral red favoured by hummingbirds and visited these pale coloured flowers more often and for longer total periods over the experimental period.The study found that just these two simple genetic changes engineered by the researchers were required to affect the preference of hawkmoth pollinators."We expected the hawkmoths to show some preference between colours, but their preferences were extremely strong," said first author Dr Kelsey Byers of the John Innes Centre and formerly based at the University of Washington (Seattle, WA, USA) where this research took place."Our study shows that changes in flowering plant pollination syndrome can proceed through relatively few genetic changes, and this further suggests that only a few simple genetic changes might be required for the origin of a new species," she added.Charles Darwin -- fascinated by what he described as the "abominable mystery" of diverse flowering plant species -- famously predicted that the Malagasy star orchid (Angraecum sesquipedale) which has a white flower and 35cm nectar spur, must be pollinated by a (then undiscovered) hawkmoth with a 35cm proboscis. Exactly such a hawkmoth pollinator was discovered decades after his prediction, confirming his hypothesis.This study likewise inspires a prospective approach to the understanding of plant speciation by pollinator shift -- one of making predictions and testing them experimentally using new trait combinations synthesised in the lab. This contrasts with the classic retrospective approach which involves comparing related plants with different pollinators for differences in key floral traits and the effects of these on pollinator preference."We have shown that the critical steps towards the origin of a new, experimentally synthesised hawkmoth-pollinated plant species can be predicted based upon a fundamental knowledge of pollination syndromes and genetics," said Dr Byers.So far, the experiments have been confined to the laboratory using lab-reared insects and one potential future direction of the research is to test the hypothesis in nature with wild insects to determine if a novel species could persist in the external environment.
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Agriculture & Food
| 2,021 |
March 29, 2021
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https://www.sciencedaily.com/releases/2021/03/210329085929.htm
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Six novel variants for CRISPR-Cas12a in plants, expanding genome engineering
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In a new publication in
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"We are excited about this paper because we've contributed two major breakthroughs," says Qi. "First, we've reported multiple Cas12a tools with genome editing capabilities in plants for the first time, and found one [Mb2Cas12a] that hugely broadens the targeting range of Cas12a. Second, we've developed a very efficient system that can edit many different sites at once [multiplexed editing], and that allows us to edit 16 different genes in rice in a single generation."As Qi explains, Cas12a (like other CRISPR systems) has typically been tied to targeting a specific short sequence of DNA known as a PAM sequence. The PAM sequence is what CRISPR systems typically use to identify where to possibly make their molecular cuts in DNA. However, the new Mb2Cas12a variant introduced by Qi works under relaxed PAM requirements, broadening the scope of what can be targeted for editing the way Qi's lab recently did for CRISPR-Cas9.In addition to this discovery, the multiplexed editing system introduced for Cas12a in plants provides specific strategies for efficiently editing multiple sites across the genome all at once. For this proof-of-concept, Qi's team first targeted six different sites in the genome to enhance rice yield and disease resistance. But when this was successful, the team didn't stop there."I wanted to add more targets to see if there is any limit," explains Qi. "So we added 10 more and tried to target 16 sites, and we found that across almost all rice chromosomes, we had an amazingly high efficiency with all sites being edited all at once in one generation. And that doesn't even represent the upper limit necessarily, but it is the most genes in a plant that has ever been recorded as being edited all at once in one generation for Cas12a."This system has major implications for precision breeding and the efficiency of food production, says Qi. "For precision breeding, how many genes you can edit at once is really practically important because you can target almost anything and really tailor the product. We targeted disease resistance and yield, but you can add more traits like nitrogen use efficiency, climate resilience traits such as temperature tolerance, and more. It is really a robust system."Qi is currently doing work to examine the off-targeting effects of editing more genes at once with more relaxed target site requirements. But in addition to these contributions, this paper also demonstrated Cas12a's utility as a synthetic repressor of genes in the model plant Arabidopsis as another tool for genome engineering."You can regulate activation or repression of certain genes by using CRISPR not as a cutting tool, but instead as a binding tool to attract activators or repressors to induce or suppress gene expression to engineer desirable traits. In this case, Cas12a is acting as glue, not as scissors. You use an inactivated form of Cas12a to inactivate the expression of other genes. It's a great new tool for the industry and for future research."Future work will expand these tools out of rice and Arabidopsis, and into all kinds of plants and crops. "This type of technology helps increase crop yield and sustainably feed a growing population in a changing world," says Qi. "I am very pleased to continue to expand the impacts of CRISPR technologies."
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Agriculture & Food
| 2,021 |
March 25, 2021
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https://www.sciencedaily.com/releases/2021/03/210325145905.htm
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Plant gene found in insect, shields it from leaf toxins
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Millions of years ago, aphid-like insects called whiteflies incorporated a portion of DNA from plants into their genome. A Chinese research team, publishing March 25th in the journal
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"This seems to be the first recorded example of the horizontal gene transfer of a functional gene from a plant into an insect," says co-author Ted Turlings, a chemical ecologist and entomologist at the University of Neuchâtel, in Switzerland. "You cannot find this gene, BtPMaT1, which neutralizes toxic compounds produced by the plant, in any other insect species."Scientists believe that plants probably use BtPMaT1 within their own cells to store their noxious compounds in a harmless form, so the plant doesn't poison itself. The team, led by Youjun Zhang from the Institute of Vegetables and Flowers at the Chinese Academy of Agricultural Sciences, used a combination of genetic and phylogenetic analyses, to reveal that roughly 35 million years ago, whiteflies stole this defense gene, granting the insect the ability to detoxify these compounds for themselves."We think a virus within the plant may have taken up this BtPMaT1 gene and, after ingestion by a whitefly, the virus then must have done something inside the insect whereby that gene was integrated into the whiteflies genome," says Turlings. "Of course, this is an extremely unlikely event, but if you think about millions of years and billions of individual insects, viruses, and plants across time, once in a while this could happen, and if the acquired gene is a benefit to the insects, then it will be evolutionarily favored and may spread."Whiteflies have become a major agricultural pest worldwide, able to attack at least 600 different species of plants worldwide. "One of the questions we've been asking ourselves is how these insects acquired these incredible adaptations to circumvent plant defenses, and with this discovery we have revealed at least one reason as to why," Turlings says.Using this knowledge, Turlings' Chinese colleagues created a strategy to undo the whiteflies' stolen superpower. They developed a small RNA molecule that interferes with the whiteflies' BtPMaT1 gene, making the whiteflies susceptible to the plant's toxic compounds."The most exciting step of this design was when our colleagues genetically manipulated tomato plants to start producing this RNA molecule" says Turlings. "Once the whiteflies fed on the tomatoes and ingested the plant-produced RNA, their BtPMaT1 gene was silenced, causing 100% mortality of the insect, but the genetic manipulation had no impact on the survival of other insects that were tested."With focused efforts to produce genetically modified crops that are able to silence the whitefly gene, this could function as a targeted strategy for pest control to combat agricultural devastation caused by whitefly populations."There are definitely still some hurdles this method needs to get over, most notably the skepticism about using transgenic plants," he says "But in the future, I do see this as a very clear way of controlling whiteflies because now we know exactly the mechanism behind it, and we are equipped to deal with possible changes in the whitefly gene that may arise.
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Agriculture & Food
| 2,021 |
March 25, 2021
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https://www.sciencedaily.com/releases/2021/03/210325115411.htm
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Ancient megafaunal mutualisms and extinctions as factors in plant domestication
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By clearing forests, burning grasslands, plowing fields and harvesting crops, humans apply strong selective pressures on the plants that survive on the landscapes we use. Plants that evolved traits for long-distance seed-dispersal, including rapid annual growth, a lack of toxins and large seed generations, were more likely to survive on these dynamic anthropogenic landscapes. In the current article, researchers argue that these traits may have evolved as adaptations for megafaunal mutualisms, later allowing those plants to prosper among increasingly sedentary human populations.
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The new study hypothesizes that the presence of specific anthropophilic traits explains why a select few plant families came to dominate the crop and weed assemblages around the globe, such as quinoa, some grasses, and knotweeds. These traits, the authors argue, also explain why so many genera appear to have been domesticated repeatedly in different parts of the world at different times. The 'weediness' and adaptability of those plants was the result of exaptation traits, or changes in the function of an evolutionary trait. In this way, rather than an active and engaged human process, certain plants gradually increased in prominence around villages, in cultivated fields, or on grazing land.Grasses and field crops weren't the only plants to use prior adaptations to prosper in human landscapes; select handfuls of trees also had advantageous traits, such as large fleshy fruits, resulting from past relationships with large browsers. The rapid extinction of megafauna at the end of the Pleistocene left many of these large-fruiting tree species with small, isolated populations, setting the stage for more dramatic changes during later hybridization. When humans began moving these trees they were likely to hybridize with distant relatives, resulting, in some cases, in larger fruits and more robust plants. In this way, the domestication process for many long-generation perennials appears to have been more rapid and tied into population changes due to megafaunal extinctions."The key to better understanding plant domestication may lay further in the past than archaeologists have previously thought; we need to think about the domestication process as another step in the evolution of life on Earth, as opposed to an isolated phenomenon," states Dr. Robert Spengler. He is the director of the archaeobotanical laboratories at the Max Planck Institute for the Science of Human History in Jena, Germany, and the lead investigator on this paper.This publication is a result of archaeologists, geneticists, botanists, and paleontologists contributing insights from their unique disciplines to reframe the way scholars think about domestication. The goal of the collaboration is to get researchers to consider the deeper ecological legacies of the plants and the pre-cultivation adaptations that they study.Prof. Nicole Boivin, director of the Department of Archaeology at the Max Planck Institute in Jena, studies the ecological impacts of humans deep in the past. "When we think about the ecology of the origins of agriculture, we need to recognize the dramatic changes in plant and animal dynamics that have unfolded across the Holocene, especially those directly resulting from human action," she adds.Ultimately, the scholars suggest that, rather than in archaeological excavations, laboratories, or in modern agricultural fields, the next big discoveries in plant domestication research may come from restored megafaunal landscapes. Ongoing research by Dr. Natalie Mueller, one of the authors, on North American restored prairies is investigating potential links between bison and the North American Lost Crops. Similar studies could be conducted on restored megafaunal landscapes in Europe, such as the Bia?owieski National Park in Poland, the Ust'-Buotoma Bizon Park or Pleistocene Park in Sakha Republic, Russia.Dr. Ashastina, another author on the paper and a paleontologist studying Pleistocene vegetation communities in North Asia, states, "these restored nature preserves provide a novel glimpse deep into the nature of plant and animal interactions and allow ecologists, not only to directly trace vegetation changes occurring under herbivore pressure in various ecosystems, but to disentangle the deeper legacies of these mutualisms."
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Agriculture & Food
| 2,021 |
March 24, 2021
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https://www.sciencedaily.com/releases/2021/03/210324170814.htm
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Genome sequenced for pesky pumpkin pathogen
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Pumpkin growers dread the tiny tan scabs that form on their fruit, each lesion a telltale sign of bacterial spot disease. The specks don't just mar the fruit's flesh, they provide entry points for rot-inducing fungus and other pathogens that can destroy pumpkins and other cucurbits from the inside out. Either way, farmers pay the price, with marketable yields reduced by as much as 90%.
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Despite the disease's severity, scientists don't know much about the genetics of the pathogen that causes it; nearly all the molecular information required for accurate diagnostic testing and targeted treatments is lacking for the disease.In a new study, University of Illinois scientists, with the help of two undergraduate students, have assembled the first complete genome for the bacteria that causes the disease, Xanthomonas cucurbitae, and identified genes that are activated during infection."Assembling a complete circular genome means we now have the resources to better understand what's happening in the field. We can use this information to look at how the pathogen is spreading, whether there are differences in host specificity among sub-populations or strains, or how likely it is to develop resistance to chemical controls," says Sarah Hind, assistant professor in the Department of Crop Sciences at Illinois and senior author on the After sequencing the genome, Hind's group compared it to genomes from 12 other Xanthomonas species that cause diseases in a variety of crop plants like tomato, rice, citrus, and wheat. Surprisingly, given its penchant for creating havoc in the field, Xanthomonas cucurbitae had the smallest genome and had fewer genes known to be important for other Xanthomonas species to cause disease."As this pathogen lacks many of the known virulence (i.e., disease-causing) genes, we don't know exactly which genes are needed by the pathogen to infect cucurbit plants," Hind says. "It could be something we've never seen before, such as a new gene or a mechanism that evolved in this species that isn't seen in the rest of the family. That could be very exciting."To get closer to an answer, the research team grew the bacteria in liquid media that mimicked its host environment and identified more than 400 genes whose expression was altered when the pathogen interacted with its "host." In particular, they observed increased expression of genes for enzymes related to the breakdown of plant tissues, which are key for further development of the disease.If Hind's team can learn more about these factors and how cucurbits respond to them, there may be a way to prevent the bacteria from penetrating pumpkin fruits in the first place. "That would really save the farmers," she says. "They don't care as much when it gets on the leaves, but if it infects the fruit, they're in trouble."Hind adds, "This project wouldn't have been possible without the contributions of some really talented undergraduate students. We love having students participate in our research. They bring a sense of enthusiasm and eagerness -- as well as really creative ideas -- to the lab that would be hard to generate otherwise."Although both students graduated, see new Crop Sciences students contributing to Hind's other pumpkin projects in this video. High school and transfer students can learn more about Crop Sciences coursework online.
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Agriculture & Food
| 2,021 |
March 24, 2021
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https://www.sciencedaily.com/releases/2021/03/210324113350.htm
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For ancient farmers facing climate change, more grazing meant more resilience
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Humans are remarkably adaptable, and our ancestors have survived challenges like the changing climate in the past. Now, research is providing insight into how people who lived over 5,000 years ago managed to adapt.
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Madelynn von Baeyer Ph.D. '18, now at the Max Planck Institute for the Science of Human History, UConn Associate Professor of Anthropology Alexia Smith, and Professor Sharon Steadman from The State University of New York College at Cortland recently published a paper in the The work was conducted as von Baeyer's doctoral research at Çadr Höyük, a site located in Turkey that is unique because it has been continuously occupied for thousands of years."I was interested in studying how plant use was impacted by changing cultural patterns. This fit Steadman's research goals for Çadır Höyük really well," says von Baeyer.Smith explains the site is situated in an area with rich agricultural and pasture land that sustained generations through time. Professor Sharon Steadman from The State University of New York College at Cortland photographing the dig site. (Contributed photo)"People would build a mud brick structure, and over the years the structure is either abandoned or collapses and the people just build on top of it," Smith says. "Eventually these villages look like they have been built on hills, but they're really just occupations going up and up."Just as the occupants built new layers up, the archaeologists excavate down to get a glimpse of history and how lives changed over the millennia. Within the layers, archaeobotanists like von Baeyer and Smith look for ancient plant remains; for instance, intentionally or unintentionally charred plant matter. Though wood was often used, much can be learned by looking at the remains of fires fueled by livestock dung, says Smith: "The dung contains seeds that give clues about what the animals were eating."Von Baeyer explains the research process: "Archaeobotanical research has three, vastly different, main stages: data collection, identification, and data analysis. Data collection is in the field, on an archaeological dig, getting soil samples and extracting the seeds from the dirt; identification is in the lab, identifying all the plant remains you collected from the field; and data analysis to tell a full story. I love every step."The focus was on a time period called the Late Chalcolithic, roughly 3700-3200 years before the common era (BCE). By referencing paleo-climatic data and Steadman's very detailed phasing at Çadır Höyük, the researchers were able to discern how lifestyles changed as the climate rapidly shifted in what is called the 5.2 kya event, an extended period of aridity and drought at the end of the fourth millennium BCE.With climate change, there are lots of strategies that can be used to adapt says Smith, "They could have intensified, diversified, extensified, or abandoned the region entirely. In this case they extensified the area of land used and diversified the herds of animals they relied upon."Zooarchaeologists on the site examined the bones to further demonstrate the shift in the types of animals herded, while the seeds from the dung-fueled fires at the dig site gave clues to what the animals were eating.Smith says, "We know they were herding cattle, sheep, goats, and pigs, and we saw a shift to animals that are grazers. They all have a different diet, and by diversifying you are maximizing the range of potential calories that can eventually be consumed by humans."By employing this mixed strategy, the people of Çadır Höyük were ensuring their survival as the climate became increasingly dry. Smith says that at the same time they continued to grow wheat, barley, chickpeas, and lentils, among other crops for humans, while the animals grazed on crops not suitable for human consumption -- a strategy to maximize resources and resilience.Von Baeyer says she was not expecting to make an argument about climate and the environment at the outset of the study."What this study does is pretty rare in archaeobotany by tracing a shift due to climate change over a relatively short time period," she says. "Often when archaeobotanical studies talk about shifts in plant use over time, it's over large cultural changes. This study looks at a shift that only spans 500 years."Though the circumstances are not exactly the same as they were nearly 6000 years ago, there are lessons we can apply today, says von Baeyer."We can take this idea of shifting animal management and feeding practices and make it work in a current context," she says. "I think that this case study, and other studies that use archaeological data to examine climate change, expands the range of possibilities for solutions to shifting environmental conditions. I think archaeological case studies invite more out of the box thinking than just current case studies. Right now, we need to think as creatively as possible to come up with sustainable and efficient responses to climate change."
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Agriculture & Food
| 2,021 |
March 23, 2021
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https://www.sciencedaily.com/releases/2021/03/210323150739.htm
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Domestication and industrialization lead to similar changes in gut microbiota
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Domestication has a consistent effect on the gut microbiota of animals and is similar to the effects of industrialisation in human populations, with ecological differences such as diet having a strong influence.
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These findings, published today in Animals typically have complex communities of microbes living in their gut that can strongly influence functions such as immunity and metabolism. These communities can be extremely diverse and differ greatly between species and even individuals. We know, for instance, that domesticated animals, such as lab mice, have different gut microbial communities than their wild relatives. We have even seen large changes in the gut microbiota of industrialised human populations, some of which have been linked to the rise of certain diseases.During domestication, animals experienced profound ecological changes that likely shaped their gut microbiota. "Domesticated animals and industrialised human populations potentially experienced similar ecological changes such as less diverse, more easily digestible diets, higher population densities, and more medical interventions," explains first author Aspen Reese, who was a postdoctoral Junior Fellow in the Society of Fellows, Harvard University, US, at the time the study was carried out, and is now Assistant Professor at the University of California, San Diego, US. "We wanted to find out if domestication had consistent effects on the gut microbiota of animals and if the effects were indeed similar to those of industrialisation in humans."To assess the effects of domestication, the team sequenced and compared microbial DNA extracted from fecal samples of 18 species of wild and domesticated mammals. They found that domestication did have a clear global effect on gut microbiota, although the specific differences depended on the species.Domestication involves strong selection pressure on animals, leading to important genetic and physiological changes that may also affect gut microbial communities. To unpack the relative roles of ecology and genetics, the team then swapped the diets of wild and domesticated animals. They found that the gut microbial communities of related animals, such as wolves and dogs, became much more similar to one another, supporting the idea that altered diets explain at least some of the changes in the gut microbiota seen with domestication.To understand whether such differences also occur in humans, they then compared the gut microbial communities of humans to those of chimpanzees, one of our closest living relatives, and between humans living in industrialised versus non-industrialised populations. They found that differences between the gut microbiota of humans and chimpanzees were similar to those seen between domesticated and wild animals, with the largest changes evident in industrialised populations. Because all humans are equally related to chimpanzees, these results showed that ecological factors rather than genetics drive aspects of the gut microbiota shared between domesticated animals and humans living in industrialised populations."Our research highlights that the flexibility of the gut microbiota likely helps animals and humans respond to rapid ecological change," concludes senior author Rachel Carmody, Assistant Professor in the Department of Human Evolutionary Biology at Harvard University. "But, at the same time, this flexibility can create opportunities for mismatch between the gut microbiota we have and the one our bodies have evolved to expect. As we increasingly appreciate the central role of the gut microbiota in biology, understanding the factors that shape it in animals and humans may help us identify new ways to improve experimental animal models, the wellbeing of animals we depend on, and ultimately, human health."
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Agriculture & Food
| 2,021 |
March 23, 2021
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https://www.sciencedaily.com/releases/2021/03/210323131307.htm
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The lambs break their silence
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A study of ancient bones shows that Early Neolithic sheep-breeders were faced with high levels of mortality among young animals in their herds. A statistical model, partly developed at Ludwig-Maximilians-Universitaet (LMU) in Munich, allowed the age distribution of the bones to be precisely determined.
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In the 8th millennium BCE, early sheep-herders were already aware that the conditions under which their animals were housed had an impact on mortality rates among the lambs. This one result of a study researchers led by Nadja Pöllath (a curator at the State Collection for Anthropology and Palaeoanatomy in Munich), LMU zooarchaeologist Joris Peters (who is also the Director of the state collection) and LMU statistician Sevag Kevork have now taken a closer look at the bones of unborn and neonatal lambs, which form part of the collections studied by them. The material comes from the Early Neolithic site Aşıklı Höyük, one of the largest and best investigated settlements from this period in Central Anatolia. The site was occupied from 8350 to around 7300 BCE, and the study reveals that the life expectancy of newborn lambs gradually increased over this timespan. The researchers attribute this finding to improvements in husbandry of the herds, which enabled a larger proportion of neonates to survive the nursing period, and be let out to graze the nearby pastures.The archaeological remains that have come to light at Aşıklı Höyük provide valuable information, not only on its domestic architecture and cultural practices, but also on the surrounding vegetation and the diets of the people and animals living in the area. Moreover, it sheds light on the development of agriculture and animal husbandry during the Early Neolithic period. The finds indicate that, in the settlement's earliest phase, its inhabitants still obtained their meat mainly from hunting. Later on, however, domesticated animals - primarily sheep - supplied much of the animal protein consumed. The discovery of compacted dung layers within the settlement indicates that sheep were kept for longer periods within the boundaries of the settlement.A new analysis of the age distribution of the animal bones found at Aşıklı Höyük illustrates the problems with which early sheep-herders were confronted - and on how they learned to mitigate them. Most of the conventional approaches used to determine the exact age at which the animals died focus on teeth. However, such methods are not sufficiently sensitive to enable researchers to reliably differentiate between developmental stages in very young animals - in this case, sheep covering the age range from the fetus to newborns and juveniles.In order to determine the ages of fetuses and lambs as accurately as possible, the researchers developed a new statistical model. They first analyzed the morphology of the humerus or upper-arm bone in a sample of modern sheep breeds, based on material kept in anatomical reference collections in the US, the UK, Spain, Portugal and Germany, and used the results to construct a comparative model for Neolithic sheep. In this way, the age at death of the bones of lambs from Aşıklı Höyük could be precisely determined. "Our analyses were of great value in enabling us to narrow down the range of possible ages of death in fetuses and lambs," says Nadja Pöllath. "We now have a better understanding of the difficulties that early herders faced in the early phases of sheep domestication in Aşıklı Höyük." Infections were the primary causes of early mortality, together with malnutrition and dietary deficiencies. In addition, the animals were kept under overcrowded conditions. When they were subsequently let out to grass their health improved. The zooarchaeological data also suggest that, towards the end of the occupation of Aşıklı Höyük, fetal mortality fell and more lambs survived. Prof. Peters concludes: "Our research thus proves for the first time that learning by doing determined the early phase of livestock farming in the 9th and 8th millennia BCE."
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Agriculture & Food
| 2,021 |
March 22, 2021
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https://www.sciencedaily.com/releases/2021/03/210322112940.htm
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Agricultural biodiversity: Different perceptions in science and practice
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For the study, 209 farmers and 98 environmental scientists were asked how they perceive agricultural biodiversity and its management in Germany and Austria. "The results show that the perceptions of scientists and farmers on biodiversity, ecosystem services and management measures are very different," says Bea Maas, lead author from the University of Vienna. "Especially the diverging perceptions of information sources that are important for agricultural decisions show need for more cross-disciplinary collaboration in sustainable development processes," adds Maas.
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The survey integrated transdisciplinary data and concepts and included demographic factors in the analysis of responses. Results showed that scientists rated biodiversity, agri-environmental programs and conservation measures as more important to agricultural production, ecosystem resilience and sustainability than farmers. "Scientists also valued scientific information as more important for agricultural decisions, while farmers valued government and agricultural sector information sources more," explains Anett Richter, co-author of the study from the Thünen Institute in Germany. Richter adds, "Critically, female farmers and farmers with higher education, or utilizing organic farming methods, rated biodiversity and its conservation as more important than other farmers." Co-author Yvonne Fabian from Agroscope in Switzerland explains: "These different perspectives of scientists and farmers reveal crucial knowledge and communication gaps between agricultural research and practice." "Our findings provide new insights for the key challenge of better integrating research, agriculture and policy practice," concludes co-author Sara Kross from Columbia University in the US.The authors provide four specific recommendations for action on how knowledge and experience can be shared and used more effectively between agricultural science and practice:First, make scientific information more accessible to practitioners by promoting and establishing education and advise programs for farmers. Second, develop targeted approaches to agricultural research and practice that integrate diverse stakeholder perspectives in their design and application. Third and fourth, support inclusive and integrative collaboration between science and practice by actively promoting cross-disciplinary communication. These efforts require "partnerships and political commitment at the highest level to make inclusive approaches central to the development of sustainable agriculture" according to Maas and her co-authors.
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Agriculture & Food
| 2,021 |
March 18, 2021
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https://www.sciencedaily.com/releases/2021/03/210318101549.htm
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Sheep vs. goats: Who are the best problem solvers?
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When it comes to adapting to new situations, goats are a step ahead. Compared to sheep, they can more quickly adapt to changing environmental conditions. These are the findings of a new study by researchers at Martin Luther University Halle-Wittenberg (MLU) and the Leibniz Institute for Farm Animal Biology (FBN) which were published in
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Sheep and goats have many things in common: They are closely related genetically, roughly the same size, have similar social structures, and have both been domesticated by humans over approximately the same amount of time. They do, however, differ greatly when it comes to their foraging strategies. "While sheep are grazers, goats are browsers and prefer buds and fresh shoots," explains Dr Camille Raoult from MLU who led the study together with Dr Christian Nawroth from FBN. The experiments were conducted at the Agroscope research centre in Switzerland, at Queen Mary University London (QMUL) and the Buttercups Sanctuary for Goats in Kent."It is important that animals are able to react swiftly to a changing environment because this allows them to find and exploit new food sources," says Nawroth. The team therefore wanted to investigate how both animal species react to new spatial obstacles. The experimental set-up of the study was rather straightforward: one animal at a time was led to the end of a small enclosure. Another person stood at the opposite end offering food. In between was a fence with a gap -- the direct path was blocked each time. The researchers observed the animals' behaviour, specifically, whether they moved directly towards the gap, and recorded the time it took them to reach the food. After a few rounds, the position of the gap in the fence was changed. The animals then repeated the test. A total of 21 goats and 28 sheep completed the experiment.The results: In the first round with the newly located gap, the goats managed to walk around the obstacle easier and faster, although the sheep reached their goal faster on average. Both the sheep and goats were initially puzzled by the new position of the gap and needed a few attempts to adjust to the new situation. Afterwards, they made fewer mistakes. The experiments could not be carried out under identical conditions at both locations, but the results were nevertheless clear: "Goats appear to adapt better and more accurately to new situations and move with less perseveration around the obstacle when the gap has changed. This suggests that they are more cognitively flexible than sheep," says co-author Dr Britta Osthaus from Canterbury Christ Church University in summary. One possible reason for the differences could be their different foraging strategies, the researcher adds.The study was supported by the Swiss Federal Food Safety and Veterinary Office, the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) and the US animal welfare organization Farm Sanctuary.
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Agriculture & Food
| 2,021 |
March 17, 2021
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https://www.sciencedaily.com/releases/2021/03/210317141622.htm
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Honey bee behavior from within the hive
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Unique video from within beehives provides special insight into honey bee behaviors, according to a study published March 17, 2021 in the open-access journal
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Though the European honey bee (For these videos, the authors continuously recorded truncated honeycomb cells within the brood area of their observation hives with the frames turned 90 degrees for visibility, permitting a sideways view into the cells in the middle of the colony.The recordings show a range of worker, offspring, and queen behaviors within the brood cells, including the queen's egg laying; embryonic hatching and larval cocooning; nurse worker bees' inspection and feeding of larva; workers' use of wax scales and existing nest material to remodel combs; storage of pollen and nectar in cells; and hygienic practices, such as cannibalism, grooming and surface cleaning. Additionally, Siefert and colleagues captured several processes previously undocumented, such as mouth-to-mouth feeding from nurse bees to larvae as well as nurse bee thermoregulation within cells containing the developing brood prompting the descent of eggs within their comb cells.The wealth of video recordings providing specific instances of honeybee behavior will prove insightful for scientists as well as beekeepers and the general public. The authors especially hope their material will help raise awareness of the critical declines in pollinator and bee populations, and encourage the use of their work for educational purposes.The authors add: "In this study, the authors provide a comprehensive source of online video material that offers a view of honey bee behavior within comb cells of a functioning colony. By providing a new mode of observation for the scientific community, beekeepers, and the general public the authors call attention to the general decline of insect biomass and diversity."
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Agriculture & Food
| 2,021 |
March 17, 2021
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https://www.sciencedaily.com/releases/2021/03/210317141619.htm
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Feeding cattle seaweed reduces their greenhouse gas emissions 82 percent
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A bit of seaweed in cattle feed could reduce methane emissions from beef cattle as much as 82 percent, according to new findings from researchers at the University of California, Davis. The results, published today (March 17) in the journal
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"We now have sound evidence that seaweed in cattle diet is effective at reducing greenhouse gases and that the efficacy does not diminish over time," said Ermias Kebreab, professor and Sesnon Endowed Chair of the Department of Animal Science and director of the World Food Center. Kebreab conducted the study along with his Ph.D. graduate student Breanna Roque."This could help farmers sustainably produce the beef and dairy products we need to feed the world," Roque added.Over the course of five months last summer, Kebreab and Roque added scant amounts of seaweed to the diet of 21 beef cattle and tracked their weight gain and methane emissions. Cattle that consumed doses of about 80 grams (3 ounces) of seaweed gained as much weight as their herd mates while burping out 82 percent less methane into the atmosphere. Kebreab and Roque are building on their earlier work with dairy cattle, which was the world's first experiment reported that used seaweed in cattle.Greenhouse gases are a major cause of climate change, and methane is a potent greenhouse gas. Agriculture is responsible for 10 percent of greenhouse gas emissions in the U.S., and half of those come from cows and other ruminant animals that belch methane and other gases throughout the day as they digest forages like grass and hay.Since cattle are the top agricultural source of greenhouse gases, many have suggested people eat less meat to help address climate change. Kebreab looks to cattle nutrition instead."Only a tiny fraction of the earth is fit for crop production," Kebreab explained. "Much more land is suitable only for grazing, so livestock plays a vital role in feeding the 10 billion people who will soon inhabit the planet. Since much of livestock's methane emissions come from the animal itself, nutrition plays a big role in finding solutions."In 2018, Kebreab and Roque were able to reduce methane emissions from dairy cows by over 50 percent by supplementing their diet with seaweed for two weeks. The seaweed inhibits an enzyme in the cow's digestive system that contributes to methane production.In the new study, Kebreab and Roque tested whether those reductions were sustainable over time by feeding cows a touch of seaweed every day for five months, from the time they were young on the range through their later days on the feed lot.Four times a day, the cows ate a snack from an open-air contraption that measured the methane in their breath. The results were clear. Cattle that consumed seaweed emitted much less methane, and there was no drop-off in efficacy over time.Results from a taste-test panel found no differences in the flavor of the beef from seaweed-fed steers compared with a control group. Similar tests with dairy cattle showed that seaweed had no impact on the taste of milk.Also, scientists are studying ways to farm the type of seaweed -- Asparagopsis taxiformis -- that Kebreab's team used in the tests. There is not enough of it in the wild for broad application.Another challenge: How do ranchers provide seaweed supplements to grazing cattle on the open range? That's the subject of Kebreab's next study.Kebreab and Roque collaborated with a federal scientific agency in Australia called the Commonwealth Scientific and Industrial Research Organization, James Cook University in Australia, Meat and Livestock Australia, and Blue Ocean Barns, a startup company that sources, processes, markets and certifies seaweed-based additives to cattle feed. Kebreab is a scientific adviser to Blue Ocean Barns."There is more work to be done, but we are very encouraged by these results," Roque said. "We now have a clear answer to the question of whether seaweed supplements can sustainably reduce livestock methane emissions and its long term effectiveness."Support for the research comes from Blue Ocean Barns, the David and Lucile Packard Foundation and the Grantham Foundation.
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Agriculture & Food
| 2,021 |
March 17, 2021
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https://www.sciencedaily.com/releases/2021/03/210317111815.htm
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Plants would grow well in solar cell greenhouses
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A recent study shows that lettuce can be grown in greenhouses that filter out wavelengths of light used to generate solar power, demonstrating the feasibility of using see-through solar panels in greenhouses to generate electricity.
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"We were a little surprised -- there was no real reduction in plant growth or health," says Heike Sederoff, co-corresponding author of the study and a professor of plant biology at North Carolina State University. "It means the idea of integrating transparent solar cells into greenhouses can be done."Because plants do not use all of the wavelengths of light for photosynthesis, researchers have explored the idea of creating semi-transparent organic solar cells that primarily absorb wavelengths of light that plants don't rely on, and incorporating those solar cells into greenhouses. Earlier work from NC State focused on how much energy solar-powered greenhouses could produce. Depending on the design of the greenhouse, and where it is located, solar cells could make many greenhouses energy neutral -- or even allow them to generate more power than they use.But, until now, it wasn't clear how these semi-transparent solar panels might affect greenhouse crops.To address the issue, researchers grew crops of red leaf lettuce (Lactuca sativa) in greenhouse chambers for 30 days -- from seed to full maturity. The growing conditions, from temperature and water to fertilizer and CO2 concentration, were all constant -- except for light.A control group of lettuces was exposed to the full spectrum of white light. The rest of the lettuces were dived into three experimental groups. Each of those groups was exposed to light through different types of filters that absorbed wavelengths of light equivalent to what different types of semi-transparent solar cells would absorb."The total amount of light incident on the filters was the same, but the color composition of that light was different for each of the experimental groups," says Harald Ade, co-corresponding author of the study and the Goodnight Innovation Distinguished Professor of Physics at NC State."Specifically, we manipulated the ratio of blue light to red light in all three filters to see how it affected plant growth," Sederoff says.To determine the effect of removing various wavelengths of light, the researchers assessed a host of plant characteristics. For example, the researchers paid close attention to visible characteristics that are important to growers, grocers and consumers, such as leaf number, leaf size, and how much the lettuces weighed. But they also assessed markers of plant health and nutritional quality, such as how much CO2 the plants absorbed and the levels of various antioxidants."Not only did we find no meaningful difference between the control group and the experimental groups, we also didn't find any significant difference between the different filters," says Brendan O'Connor, co-corresponding author of the study and an associate professor of mechanical and aerospace engineering at NC State."There is also forthcoming work that delves into greater detail about the ways in which harvesting various wavelengths of light affects biological processes for lettuces, tomatoes and other crops," Sederoff says."This is promising for the future of solar-powered greenhouses," Ade says. "Getting growers to use this technology would be a tough argument if there was a loss of productivity. But now it is a simple economic argument about whether the investment in new greenhouse technology would be offset by energy production and savings.""Based on the number of people who have contacted me about solar-powered greenhouses when we've published previous work in this space, there is a lot of interest from many growers," O'Connor says. "I think that interest is only going to grow. We've seen enough proof-of-concept prototypes to know this technology is feasible in principle, we just need to see a company take the leap and begin producing to scale."The work was done with support from the National Science Foundation under grants 1639429 and 1905901; the Office of Naval Research, under grants N00014-20-1-2183, N00014-17-1-2242 and N00014-17-1-2204; North Carolina State University; and NextGen Nano Limited.
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Agriculture & Food
| 2,021 |
March 16, 2021
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https://www.sciencedaily.com/releases/2021/03/210316132052.htm
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Going back in time restores decades of quiet corn drama
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Corn didn't start out as the powerhouse crop it is today. No, for most of the thousands of years it was undergoing domestication and improvement, corn grew humbly within the limits of what the environment and smallholder farmers could provide.
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For its fertilizer needs, early corn made friends with nitrogen-fixing soil microbes by leaking an enticing sugary cocktail from its roots. The genetic recipe for this cocktail was handed down from parent to offspring to ensure just the right microbes came out to play.But then the Green Revolution changed everything. Breeding tools improved dramatically, leading to faster-growing, higher-yielding hybrids than the world had ever seen. And synthetic fertilizer application became de rigueur.That's the moment corn left its old microbe friends behind, according to new research from the University of Illinois. And it hasn't gone back."Increasing selection for aboveground traits, in a soil setting where we removed all reliance on microbial functions, degraded microbial sustainability traits. In other words, over the course of half a century, corn breeding altered its microbiome in unsustainable ways," says Angela Kent, professor in the Department of Natural Resources and Environmental Sciences at the University of Illinois and co-author of a new study in the International Society of Microbial Ecology Journal.Kent, along with co-authors Alonso Favela and Martin Bohn, found modern corn varieties recruit fewer "good" microbes -- the ones that fix nitrogen in the soil and make it available for crops to take up -- than earlier varieties. Instead, throughout the last several decades of crop improvement, corn has been increasingly recruiting "bad" microbes. These are the ones that help synthetic nitrogen fertilizers and other sources of nitrogen escape the soil, either as potent greenhouse gases or in water-soluble forms that eventually end up in the Gulf of Mexico and contribute to oxygen-starved "dead zones.""When I was first analyzing our results, I got a little disheartened," says Favela, a doctoral student in the Program in Ecology, Evolution, and Conservation Biology at Illinois and first author on the study. "I was kind of sad we had such a huge effect on this plant and the whole ecosystem, and we had no idea we were even doing it. We disrupted the very root of the plant."To figure out how the corn microbiome has changed, Favela recreated the history of corn breeding from 1949 to 1986 by planting a chronological sequence of 20 off-patent maize lines in a greenhouse."We have access to expired patent-protected lines that were created during different time periods and environmental conditions. We used that understanding to travel back in time and look at how the associated microbiome was changing chronologically," he says.As a source of microbes, Favela inoculated the pots with soil from a local ag field that hadn't been planted with corn or soybeans for at least two years. Once the plants were 36 days old, he sequenced the microbial DNA he collected from soil adhering to the roots."We characterized the microbiome and microbial functional genes related to transformations that occur in the nitrogen cycle: nitrogen fixation, nitrification, and denitrification," he says. "We found more recently developed maize lines recruited fewer microbial groups capable of sustainable nitrogen provisioning and more microbes that contribute to nitrogen losses."Kent says breeding focused on aboveground traits, especially in a soil context flooded with synthetic nitrogen fertilizers, may have tweaked the sugary cocktail roots exude to attract microbes."Through that time period, breeders weren't selecting for maintenance of microbial functions like nitrogen fixation and nitrogen mineralization because we had replaced all those functions with agronomic management. As we started selecting for aboveground features like yield and other traits, we were inadvertently selecting against microbial sustainability and even actively selecting for unsustainable microbiome features such as nitrification and denitrification," she says.Now that it's clear something has changed, can breeders bring good microbes back in corn hybrids of the future?Bohn, corn breeder and associate professor in the Department of Crop Sciences at Illinois, thinks it's very possible to "rewild" the corn microbiome. For him, the answer lies in teosinte, a wild grass most people would have to squint pretty hard at to imagine as the parent of modern corn.Like wild things everywhere, teosinte evolved in the rich context of an entire ecosystem, forming close relationships with other organisms, including soil microbes that made soil nutrients easier for the plant to access. Bohn thinks it should be possible to find teosinte genes responsible for creating the root cocktail that attracts nitrogen-fixing microbes. Then, it's just a matter of introducing those genes into novel corn hybrids."I never thought we would go back to teosinte because it's so far removed from what we want in our current agricultural landscape. But it may hold the key not only for encouraging these microbial associations; it also may help corn withstand climate change and other stresses," Bohn says. "We actually need to go back to teosinte and start investigating what we left behind so we can bring back these important functions."Bringing back the ability for corn to recruit its own nitrogen fixation system would allow producers to apply less nitrogen fertilizer, leading to less nitrogen loss from the system overall."Farmers don't always know how much nitrogen they will need, so, historically, they've dumped as much as possible onto the fields. If we bring these characteristics back into corn, it might be easier for them to start rethinking the way they manage nitrogen," Bohn says.Kent adds that a little change could go a long way."If we could reduce nitrogen losses by even 10% across the growing region of the Midwest, that would have huge consequences for the environmental conditions in the Gulf of Mexico," she says.
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Agriculture & Food
| 2,021 |
March 16, 2021
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https://www.sciencedaily.com/releases/2021/03/210316112306.htm
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Not just CO2: Rising temperatures also alter photosynthesis in a changing climate
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Agricultural scientists who study climate change often focus on how increasing atmospheric carbon dioxide levels will affect crop yields. But rising temperatures are likely to complicate the picture, researchers report in a new review of the topic.
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Published in the Excessive heat can reduce the efficiency of enzymes that drive photosynthesis and can hinder plants' ability to regulate COThe review describes the latest scientific efforts to address these challenges."It's important to have an understanding of these issues across scales -- from the biochemistry of individual leaves to ecosystem-level influences -- in order to really tackle these problems in an informed way," said lead author Caitlin Moore, a research fellow at the University of Western Australia and an affiliate research fellow at the Institute for Sustainability, Energy, and Environment at the University of Illinois Urbana-Champaign. Moore led the review with Amanda Cavanagh, another U. of I. alumna now at the University of Essex in the U.K."Historically, there's been a lot of focus on rising CO"Take Rubisco, the key enzyme that fixes carbon dioxide into sugars, making life on Earth possible," Cavanagh said. "Rubisco speeds up as the temperature increases, but it's also prone to making mistakes."Instead of fixing carbon dioxide by binding it to sugars, a key step in photosynthesis, Rubisco sometimes fixes oxygen, initiating a different pathway that wastes a plant's resources. Higher temperatures make this more likely, Cavanagh said. At even higher temperatures, the enzyme will begin to lose its structural integrity, making it ineffective.Excessive heat can also undermine a plant's reproductive output. Other heat-sensitive enzymes are essential to the light-harvesting machinery of plants or play a role in moving sugars to different plant tissues, allowing the plant to grow and produce grains or fruits."If these little molecular machines are pushed out of the temperature range that's optimal, then they can't do their job," Cavanagh said.When temperatures rise too high, plant leaves open the pores on their surfaces, called stomata, to cool themselves. Stomata also allow plants to absorb carbon dioxide from the atmosphere, but when they're fully open, the leaf can lose too much moisture."Temperature affects the atmosphere above the plant," Moore said. "As the atmosphere heats up, it can hold additional water, so it's pulling more water from the plants."Scientists at Illinois and elsewhere are looking for ways to enhance crop plants' resilience in the face of these changes. Moore, whose work focuses on ecosystem-scale factors, said new tools that can help screen plants on a large scale are essential to that effort. For example, satellites that can detect changes in chlorophyll fluorescence in plants can indicate whether a crop is under heat stress. These changes in fluorescence are detectable before the plant shows any outward sign of heat stress -- such as their leaves turning brown. Developing these tools may enable farmers to respond more quickly to crop stress before too much damage is done.Cavanagh, who studies the molecular biology and physiology of plants, said some plants are more heat tolerant than others, and scientists are searching their genomes for clues to their success."For example, you can look at wild Australian relatives of rice that are growing in much harsher climates than most paddy rices," she said. "And you see that their enzymes are primed to work more efficiently at hotter temperatures."One goal is to transfer heat-tolerant genes to cultivated rice varieties that are more susceptible to heat stress.Other strategies include engineering structures that pump more COCollaboration between scientists focused on different scales of ecosystem and plant function -- from the atmospheric to the molecular -- is essential to the success of efforts to build resilience in crop plants, the researchers said."The world is getting hotter at a shocking rate," Cavanagh said. "And we know from global models that each increase in gross temperature degree Celsius can cause 3% to 7% losses in yield of our four main crops. So, it's not something we can ignore."What makes me optimistic is the realization that so much work is going into globally solving this problem," she said.
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Agriculture & Food
| 2,021 |
March 16, 2021
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https://www.sciencedaily.com/releases/2021/03/210316112257.htm
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Scientists develop device to 'communicate' with plants using electrical signals
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A team of scientists led by Nanyang Technological University, Singapore (NTU Singapore) has developed a device that can deliver electrical signals to and from plants, opening the door to new technologies that make use of plants.
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The NTU team developed their plant 'communication' device by attaching a conformable electrode (a piece of conductive material) on the surface of a Venus flytrap plant using a soft and sticky adhesive known as hydrogel. With the electrode attached to the surface of the flytrap, researchers can achieve two things: pick up electrical signals to monitor how the plant responds to its environment, and transmit electrical signals to the plant, to cause it to close its leaves.Scientists have known for decades that plants emit electrical signals to sense and respond to their environment. The NTU research team believe that developing the ability to measure the electrical signals of plants could create opportunities for a range of useful applications, such as plant-based robots that can help to pick up fragile objects, or to help enhance food security by detecting diseases in crops early.However, plants' electrical signals are very weak, and can only be detected when the electrode makes good contact with plant surfaces. The hairy, waxy, and irregular surfaces of plants make it difficult for any thin-film electronic device to attach and achieve reliable signal transmission.To overcome this challenge, the NTU team drew inspiration from the electrocardiogram (ECG), which is used to detect heart abnormalities by measuring the electrical activity generated by the organ.As a proof-of concept, the scientists took their plant 'communication' device and attached it to the surface of a Venus flytrap -- a carnivorous plant with hairy leaf-lobes that close over insects when triggered.The device has a diameter of 3 mm and is harmless to the plant. It does not affect the plant's ability to perform photosynthesis while successfully detecting electrical signals from the plant. Using a smartphone to transmit electric pulses to the device at a specific frequency, the team elicited the Venus flytrap to close its leaves on demand, in 1.3 seconds.The researchers have also attached the Venus flytrap to a robotic arm and, through the smartphone and the 'communication' device, stimulated its leaf to close and pick up a piece of wire half a millimetre in diameter.Their findings, published in the scientific journal The research team envisions a future where farmers can take preventive steps to protect their crops, using the plant 'communication' device they have developed.Lead author of the study, Chen Xiaodong, President's Chair Professor in Materials Science and Engineering at NTU Singapore said: "Climate change is threatening food security around the world. By monitoring the plants' electrical signals, we may be able to detect possible distress signals and abnormalities. When used for agriculture purpose, farmers may find out when a disease is in progress, even before full?blown symptoms appear on the crops, such as yellowed leaves. This may provide us the opportunity to act quickly to maximise crop yield for the population."Prof Chen, who is also Director of the Innovative Centre for Flexible Devices (iFLEX) at NTU, added that the development of the 'communication' device for plants monitoring exemplifies the NTU Smart Campus vision which aims to develop technologically advanced solutions for a sustainable future.Seeking to improve the performance of their plant 'communication' device, the NTU scientists also collaborated with researchers at the Institute of Materials Research and Engineering (IMRE), a unit of Singapore's Agency for Science, Technology and Research (A*STAR).Results from this separate study, published in the scientific journal Elaborating on this study, co-lead author Professor Chen Xiaodong said, "The thermogel-based material behaves like water in its liquid state, meaning that the adhesive layer can conform to the shape of the plant before it turns into a gel. When tested on hairy stems of the sunflower for example, this improved version of the plant 'communication' device achieved four to five times the adhesive strength of common hydrogel and recorded significantly stronger signals and less background noise."Co-lead author of the Moving forward, the NTU team is looking to devise other applications using the improved version of their plant 'communication' device.Video:
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Agriculture & Food
| 2,021 |
March 12, 2021
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https://www.sciencedaily.com/releases/2021/03/210312095802.htm
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Malaria devastated humans far earlier than expected
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New bioarchaeological research shows malaria has threatened human communities for more than 7000 years, earlier than when the onset of farming was thought to have sparked its devastating arrival.
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Lead author Dr Melandri Vlok from the Department of Anatomy, University of Otago, says this ground-breaking research, published today in "Until now we've believed malaria became a global threat to humans when we turned to farming, but our research shows in at least Southeast Asia this disease was a threat to human groups well before that."This research providing a new cornerstone of malaria's evolution with humans is a great achievement by the entire team," Dr Vlok says.Still a serious health issue, as recently as 2019 the World Health Organization reported an estimated 229 million cases of malaria around the world, with 67 per cent of malaria deaths in children under the age of 5 years.While malaria is invisible in the archaeological record, the disease has changed the evolutionary history of human groups causing consequences visible in prehistoric skeletons. Certain genetic mutations can lead to the inheritance of Thalassemia, a devasting genetic disease that in its milder form provides some protection against malaria.Deep in humanity's past, the genes for malaria became more common in Southeast Asia and the Pacific where it remains a threat, but up until now the origin of malaria has not been pinpointed. This research has identified thalassemia in an ancient hunter-gatherer archaeological site from Vietnam dated to approximately 7000 years ago, thousands of years before the transition to farming in the region.In some parts of the world, slashing and burning in agricultural practice would have created pools of stagnant water attracting mosquitos carrying malaria, but in Southeast Asia these mosquitos are common forest dwellers exposing humans to the disease long before agriculture was adopted.The study Forager and farmer evolutionary adaptations to malaria evidenced by 7000 years of thalassemia in Southeast Asia is a result of combined efforts from years of investigation by a team of researchers led by Professor Marc Oxenham (currently at the University of Aberdeen) and including researchers from University of Otago, the Australian National University (ANU), James Cook University, Vietnam Institute of Archaeology and Sapporo Medical University.The research is the first of its kind to use microscopic techniques to investigate changes in bone tissue to identify thalassemia. In 2015, Professor Hallie Buckley from the University of Otago noticed changes in the bone of hunter-gatherers that made her suspicious that thalassemia might be the cause, but the bones were too poorly preserved to be certain. Professor Buckley called in microscopic bone expert Dr Justyna Miszkiewicz of ANU to investigate. Under the microscope, the ancient samples from Vietnam showed evidence for abnormal porosity mirroring modern-day bone loss complications in thalassemic patients.At the same time, Dr Vlok, completing her doctoral research in Vietnam, found changes in the bones excavated in a 4000-year-old agricultural site in the same region as the 7000-year-old hunter-gatherer site. The combined research suggests a long history of evolutionary changes to malaria in Southeast Asia which continues today."A lot of pieces came together, then there was a startling moment of realisation that malaria was present and problematic for these people all those years ago, and a lot earlier than we've known about until now," Dr Vlok adds.
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Agriculture & Food
| 2,021 |
March 11, 2021
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https://www.sciencedaily.com/releases/2021/03/210311123437.htm
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47 million year old fly found with a full belly
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It was not the fly itself that caught the scientists' attention, but its bulging abdomen suggesting it was still full with the fly's last food intake. Surprisingly, analysis of the stomach content revealed it was full with pollen from different plants. The fossil pollen from the fly's stomach was used to reconstruct the ancient environment inhabited by the fly, the biotic interactions between plant and fly, and the fly's behaviour during feeding.
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Today, bees, butterflies and bumblebees are the typical pollinators, which are also known to feed on pollen. That flies also play an important role in pollination is rarely addressed. "The rich pollen content we discovered in the fly's stomach suggests that flies were already feeding and transporting pollen 47 million years ago and shows it played an important role in the pollen dispersal of several plant taxa," says Fridgeir Grímsson from the Department of Botany and Biodiversity Research of the University of Vienna. "Flies were major pollinators in ancient (sub-)tropical equivalent ecosystems and might even have outshined the bees," the scientist concludes.The extracted pollen was dominated by grains of Decodon (waterwillow) and Parthenocissus (virgin ivy). Today, the waterwillow is a sub-shrub growing in wetlands and the shallows of lakes, suggesting open low canopy habitat. The co-dominance of virgin ivy also suggests that the fly fed on plants growing at the forest margin surrounding the ancient Messel lake. "It is likely that the fly avoided long-distance flights between food sources and sought pollen from closely associated plants," says Grímsson.
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Agriculture & Food
| 2,021 |
March 10, 2021
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https://www.sciencedaily.com/releases/2021/03/210310132348.htm
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Forget the fly swatter: Biologists map genes to fight stable flies
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Researchers hope to use an agricultural pest's genetic code against it to prevent billions of dollars in annual losses in the United States.
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Stable flies, or Stomoxys calcitrans, are spotted, tan-colored flies found around the world. They are easily mistaken for the common housefly but for one notable distinction: They bite."If you get one in your house and it bites you, it's a stable fly," said Joshua Benoit, an assistant professor of biology at the University of Cincinnati.Stable flies don't bite so much as chomp. They are the scourge of beachgoers in Florida and recreational boaters in upstate New York. According to Thomas Jefferson, they tormented signatories of the Declaration of Independence."You shoo it away and shoo it away but it's persistent and lands on you. And then it bites. And it's not a pleasant bite. It's a pretty vicious, painful bite," Benoit said.UC joined an international team that unlocked the genome of stable flies. Benoit and his students contributed to a fundamental research project called i5k that has the ambitious goal to sequence the genes of 5,000 species of arthropods, the group that includes spiders, insects and crabs."It's a pretty cool project. Molecular research on stable flies is far behind many other organisms. Our goal was to jump it up so we have a good model system to understand the biology of stable flies," Benoit said.Previously, UC worked on similar projects for bedbugs and the agricultural menaces thrips and screwworms.With stable flies, Benoit said they were looking for possible weaknesses to exploit in its genetic code. Researchers examined stable fly biology using genomic sequencing and RNA analysis over the fly's development. They also identified 1,600 genes related to stable fly reproduction, which could lead to new biological controls without the use of pesticides."Conducting research for its own sake is reward enough, but it is always heartening when the findings generate interesting novel avenues for exploration," study co-author and UC postdoctoral researcher Christopher Holmes said.The study was published in the journal "Stable flies are arguably one of the most important pests of livestock in the United States," Olafson said.The project has huge economic implications from tourism to agriculture. Nobody can nap in a beach chair with stable flies for company. The flies cause an estimated $2.2 billion in livestock production each year, according to the U.S. Department of Agriculture. Cows beset by stable flies produce less milk and put on less weight.Unlike mosquitoes, both male and female stable flies bite."It's a nonstop onslaught all the time. The flies need a blood meal to survive and reproduce. So they will keep trying to bite and trying to bite. They are very persistent," Benoit said."When you get a thousand of these biting a cow, it can have a huge impact on agricultural productivity."Olafson said the research has implications far beyond the United States."Worldwide, these flies have become a societal issue of public and political importance," she said. "Growing international agroindustries, like pineapple, coffee and sugarcane, produce large amounts of byproduct that are ideal sites for stable fly larvae to develop. These sites can produce upwards of hundreds of thousands of flies per acre. Livestock producers and communities that neighbor these industries feel the impact."UC's study also helps scientists better understand why some flies evolved to feed on blood while similar species didn't. The flies lay their eggs in wet or rotting vegetation like the wet hay or straw found around barns and stables that give them their associated name.By understanding the genes responsible for stable fly reproduction, researchers hope to design novel biological controls similar to methods that have worked to eradicate other pests such as screwworms. The USDA raises screwworms by the millions, releasing sterilized males over Central America to keep them from pushing north to plague North American cattle ranches."Any targeted control like that is probably better than widescale pesticide application, which will kill all insects. So you don't have to release chemicals into the environment," Benoit said.
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Agriculture & Food
| 2,021 |
March 9, 2021
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https://www.sciencedaily.com/releases/2021/03/210309153902.htm
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Adaptation, not irrigation recommended for Midwest corn farmers
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Farmers in the Midwest may be able to bypass the warming climate not by getting more water for their crops, but instead by adapting to climate change through soil management says a new study from Michigan State University.
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"The Midwest supplies 30% of the world's corn and soybeans," said Bruno Basso, an ecosystems scientist and MSU Foundation Professor in the Department of Earth and Environmental Sciences within the College of Natural Science. "These crops are sensitive to temperature and water changes."Previous studies have suggested that by 2050, the Midwest will need about 35% more water to sustain its current levels of corn and soybean yields. But research done by Basso and colleagues found that the data does not support this idea. The Midwest is in a unique location that typically receives ample rainfall and has deep soil, ideal for farming.The research was published March 5 in Basso, with his lab members Rafael Martinez-Feria and Lydia Rill, and MSU Distinguished Emeritus Professor Joe Ritchie, analyzed climate trends from weather stations from across the Midwest dating as far back as 1894.The researchers found that average daily temperatures during the summer have increased throughout much of the Midwest. But they also discovered that daily minimum air temperatures, usually during the nighttime, have increased while the daily maximum daytime temperatures have decreased.These trends held true during the full, 120-year weather record studied or during more 30- to 60-year time periods."Warmer temperatures generally mean that crops need more water, but that doesn't seem to be the case in the Midwest," said Basso, who is also a faculty member at MSU's W.K. Kellogg Biological Station and AgBioResearch. "Because the increase in average temperature comes from higher minimum temperatures -- the temperature at which dew is formed -- this means that the air is also becoming more humid."Ritchie, one of the co-authors on the study, said that these two contrasting trends have canceled each other out, and that so far, the potential crop water demand has remained relatively unchanged despite the warming climate.Data were entered into computer simulation models developed at MSU by Basso and Ritchie to gauge the impact if these trends continued into 2050. Martinez-Feria, another co-author on the study, said that in the worst-case scenario, the amount of water needed by crops could increase by an average of 2.5%. More conservative estimates indicate that water needs would remain practically the same, because summer rainfall would also increase.Basso cautions that although crop water needs may be similar in the future, increasing air temperatures also make droughts more likely to occur. "The impact climate change will have on the Midwest is still uncertain," he said. "We are still at risk of droughts."But instead of installing extensive and expensive irrigation systems that might only pay off under extreme droughts, Bassos advises farmers to invest in technology and regenerative soil practices that make plants more resilient and adaptable to climate change."As we continue to learn more about weather and its increased variability, farmers need to adapt, which they are starting to do," Basso said. "I feel optimistic that with the progress made in regenerative practices, genetics and digital technology solutions, we can adapt to climate and have a better chance of winning this battle against our own previous mistakes."
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Agriculture & Food
| 2,021 |
March 8, 2021
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https://www.sciencedaily.com/releases/2021/03/210308111954.htm
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Atmospheric drying will lead to lower crop yields, shorter trees across the globe
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A global observation of an ongoing atmospheric drying -- known by scientists as a rise in vapor pressure deficit -- has been observed worldwide since the early 2000s. In recent years, this concerning phenomenon has been on the rise, and is predicted to amplify even more in the coming decades as climate change intensifies.
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In a new paper published in the journal "When there is a high vapor pressure deficit, our atmosphere pulls water from other sources: animals, plants, etc.," said senior author Walid Sadok, an assistant professor in the Department of Agronomy and Plant Genetics at the University of Minnesota. "An increase in vapor pressure deficit places greater demand on the crop to use more water. In turn, this puts more pressure on farmers to ensure this demand for water is met -- either via precipitation or irrigation -- so that yields do not decrease.""We believe a climate change-driven increase in atmospheric drying will reduce plant productivity and crop yields -- both in Minnesota and globally," said Sadok.In their analysis, researchers suspected plants would sense and respond to this phenomenon in unexpected ways, generating additional costs on productivity. Findings bear out that various plant species -- from wheat, corn, and even birch trees -- take cues from atmospheric drying and anticipate future drought events.Through this process, plants reprogram themselves to become more conservative -- or in other words: grow smaller, shorter and more resistant to drought, even if the drought itself does not happen. Additionally, due to this conservative behavior, plants are less able to fix atmospheric CO"As we race to increase production to feed a bigger population, this is a new hurdle that will need to be cleared," said Sadok. "Atmospheric drying could limit yields, even in regions where irrigation or soil moisture is not limiting, such as Minnesota."On a positive note, the analysis indicates different species or varieties within species respond more or less strongly to this drying depending on their evolutionary and genetic make-up. For example, in wheat, some varieties are less responsive to this new stress compared to others, and this type of variability seems to exist within other non-crop species as well."This finding is particularly promising as it points to the possibility of breeding for genotypes with an ability to stay productive despite the increase in atmospheric drying," said Sadok.Danielle Way, a plant physiologist and co-author of the study from Western University, sees similar outcomes when it comes to ecosystems."Variation in plants' sensitivity to atmospheric drying could also be leveraged to predict how natural ecosystems will respond to climate change and manage them in ways that increase their resilience to climate change," she said.In the future, researchers believe these findings can be used to design new crop varieties and manage ecosystems in ways that make them more resilient to atmospheric drying. However, new collaborations are needed between plant physiologists, ecologists, agronomists, breeders and farmers to make sure the right kind of variety is released to farmers depending on their specific conditions."Ultimately, this investigation calls for more focused interdisciplinary research efforts to better understand, predict and mitigate the complex effects of atmospheric drying on ecosystems and food security," Sadok and Way said.The research was funded by grants from the Minnesota Wheat Research & Promotion Council, the Minnesota Soybean Research and Promotion Council and the Minnesota Department of Agriculture.
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Agriculture & Food
| 2,021 |
March 8, 2021
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https://www.sciencedaily.com/releases/2021/03/210308094320.htm
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Invasive weed may help treat some human diseases, researchers find
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Native to the southeastern United States, a weedy grass has spread northward to Canada and also made its way to Australia and Japan.
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An international team of researchers has found that "Researchers found high levels of flavonoids in the samples they extracted from the weed. These plant chemicals have significant antioxidant and anti-inflammatory properties, according to Xuan. When tested against a variety of cell lines, the extracted plant chemicals bonded to free radicals, preventing damage to the cells. At skin level, this helps prevent age spots by inhibiting a protein called tyrosinase. Among other, deeper healthful actions, this bonding also helps prevent knock-on cellular actions that can lead to type 2 diabetes.The team also specifically applied the extracted chemicals to a line of chronic myelogenous leukemia, a rare blood cancer. The extract appeared to kill off the cancer cells.Xuan said the researchers plan to establish a comprehensive process to isolate and purify the compounds responsible for known biological properties, as well as work to identify new uses. They will further test the therapeutical effects of the compounds, with the eventual goal of preparing functional pharmaceuticals for human use."Although
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Agriculture & Food
| 2,021 |
March 8, 2021
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https://www.sciencedaily.com/releases/2021/03/210308111933.htm
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Critically endangered macadamia species becomes a sophisticated plant genomic model
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One of the world's rarest tree species has been transformed into a sophisticated model that University of Queensland researchers say is the future of plant research.
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""It grows near Miriam Vale in Queensland and there are only around 100 known trees in existence."However, with funding from Hort Innovation's Tree Genomics project, and UQ's Genome Innovation Hub Professor Henry said "Professor Henry said the entire jansenii species grows in one small area. "This means we have the potential to study the diversity of the whole species," he said."This is unusual, even for rare or endangered plants -- it means we can get a lot of information about how rare plant species survive the impact of small population size and the associated genetic bottleneck.Professor Henry said that particular characteristics of "We investigated the different sequencing technologies, all the different software and algorithms that you can use in genomic sequencing, and then applied each of them to the same sample to find out what worked best," he said."It's a long, complex and very expensive process, so we wanted to use the latest technology to improve its efficiency."The Genome Innovation Hub's Ms Valentine Murigneux analysed the genome sequence and QAAFI researchers then assembled all 14 chromosomes for the species, in collaboration with laboratories in the United States. This work was published in Professor Henry said the work is of great interest globally."High quality genome sequences are proving much more useful than rough draft sequences with less errors and better outcomes for plant breeding," he said.Ms Denise Bond, Executive Officer of the Macadamia Conservation Trust said since 2018 about 60 new mature "We very much welcome the genomic research on She said the remaining three macadamias species -- "This is a wake-up call to Australia to take better care of our native macadamia species."Professor Henry said all four macadamia species -- tetraphylla, integrifolia, ternifolia and jansenii have now undergone the same analysis."It is fitting this work has been developed in Queensland using the Macadamia genus -- one of Australia's few additions to the world's food crops," he saidThe macadamia genomic work forms part of a five-year project to develop detailed high quality genome sequencing for five of Australia's key horticultural tree crops -- avocado, macadamia, mango, citrus and almond -- which account for 80 percent of Australian horticulture tree crop value."The macadamia data we have generated has been fed through to a range of projects including research on sustainably intensifying tree crop production and breeding for key commercial attributes in macadamia production," Professor Henry said.
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Agriculture & Food
| 2,021 |
March 5, 2021
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https://www.sciencedaily.com/releases/2021/03/210305150618.htm
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Cactus pear as drought-tolerant crop for sustainable fuel and food
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Could cactus pear become a major crop like soybeans and corn in the near future, and help provide a biofuel source, as well as a sustainable food and forage crop? According to a recently published study, researchers from the University of Nevada, Reno believe the plant, with its high heat tolerance and low water use, may be able to provide fuel and food in places that previously haven't been able to grow much in the way of sustainable crops.
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Global climate change models predict that long-term drought events will increase in duration and intensity, resulting in both higher temperatures and lower levels of available water. Many crops, such as rice, corn and soybeans, have an upper temperature limit, and other traditional crops, such as alfalfa, require more water than what might be available in the future."Dry areas are going to get dryer because of climate change," Biochemistry & Molecular Biology Professor John Cushman, with the University's College of Agriculture, Biotechnology & Natural Resources, said. "Ultimately, we're going to see more and more of these drought issues affecting crops such as corn and soybeans in the future."As part of the College's Experiment Station unit, Cushman and his team recently published the results of a five-year study on the use of spineless cactus pear as a high-temperature, low-water commercial crop. The study, funded by the Experiment Station and the U.S. Department of Agriculture's National Institute of Food and Agriculture, was the first long-term field trial of Opuntia species in the U.S. as a scalable bioenergy feedstock to replace fossil fuel.Results of the study, which took place at the Experiment Station's Southern Nevada Field Lab in Logandale, Nevada, showed that Opuntia ficus-indica had the highest fruit production while using up to 80% less water than some traditional crops. Co-authors included Carol Bishop, with the College's Extension unit, postdoctoral research scholar Dhurba Neupane, and graduate students Nicholas Alexander Niechayev and Jesse Mayer."Maize and sugar cane are the major bioenergy crops right now, but use three to six times more water than cactus pear," Cushman said. "This study showed that cactus pear productivity is on par with these important bioenergy crops, but use a fraction of the water and have a higher heat tolerance, which makes them a much more climate-resilient crop."Cactus pear works well as a bioenergy crop because it is a versatile perennial crop. When it's not being harvested for biofuel, then it works as a land-based carbon sink, removing carbon dioxide from the atmosphere and storing it in a sustainable manner."Approximately 42% of land area around the world is classified as semi-arid or arid," Cushman said. "There is enormous potential for planting cactus trees for carbon sequestration. We can start growing cactus pear crops in abandoned areas that are marginal and may not be suitable for other crops, thereby expanding the area being used for bioenergy production."The crop can also be used for human consumption and livestock feed. Cactus pear is already used in many semi-arid areas around the world for food and forage due to its low-water needs compared with more traditional crops. The fruit can be used for jams and jellies due to its high sugar content, and the pads are eaten both fresh and as a canned vegetable. Because the plant's pads are made of 90% water, the crop works great for livestock feed as well."That's the benefit of this perennial crop," Cushman explained. "You've harvested the fruit and the pads for food, then you have this large amount of biomass sitting on the land that is sequestering carbon and can be used for biofuel production."Cushman also hopes to use cactus pear genes to improve the water-use efficiency of other crops. One of the ways cactus pear retains water is by closing its pores during the heat of day to prevent evaporation and opening them at night to breathe. Cushman wants to take the cactus pear genes that allow it to do this, and add them to the genetic makeup of other plants to increase their drought tolerance.Bishop, Extension educator for Northeast Clark County, and her team, which includes Moapa Valley High School students, continue to help maintain and harvest the more than 250 cactus pear plants still grown at the field lab in Logandale. In addition, during the study, the students gained valuable experience helping to spread awareness about the project, its goals, and the plant's potential benefits and uses. They produced videos, papers, brochures and recipes; gave tours of the field lab; and held classes, including harvesting and cooking classes.In 2019, Cushman began a new research project with cactus pear at the U.S. Department of Agriculture -- Agricultural Research Service' National Arid Land Plant Genetic Resources Unit in Parlier, California. In addition to continuing to take measurements of how much the cactus crop will produce, Cushman's team, in collaboration with Claire Heinitz, curator at the unit, is looking at which accessions, or unique samples of plant tissue or seeds with different genetic traits, provide the greatest production and optimize the crop's growing conditions."We want a spineless cactus pear that will grow fast and produce a lot of biomass," Cushman said.One of the other goals of the project is to learn more about Opuntia stunting disease, which causes cactuses to grow smaller pads and fruit. The team is taking samples from the infected plants to look at the DNA and RNA to find what causes the disease and how it is transferred to other cactuses in the field. The hope is to use the information to create a diagnostic tool and treatment to detect and prevent the disease's spread and to salvage usable parts from diseased plants.
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Agriculture & Food
| 2,021 |
March 5, 2021
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https://www.sciencedaily.com/releases/2021/03/210305113455.htm
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Antibiotic-resistant strains of staph bacteria may be spreading between pigs raised in factory farms
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DNA sequencing of bacteria found in pigs and humans in rural eastern North Carolina, an area with concentrated industrial-scale pig-farming, suggests that multidrug-resistant Staphylococcus aureus strains are spreading between pigs, farmworkers, their families and community residents, and represents an emerging public health threat, according to a study led by researchers at the Johns Hopkins Bloomberg School of Public Health.
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S. aureus is commonly found in soil and water, as well as on the skin and in the upper respiratory tract in pigs, other animals, and people. It can cause medical problems from minor skin infections to serious surgical wound infections, pneumonia, and the often-lethal blood-infection condition known as sepsis. The findings provide evidence that multidrug-resistant S. aureus strains are capable of spreading and possibly causing illness in and around factory farm communities in the U.S. -- a scenario the authors say researchers should continue to investigate.The study was published online February 22 in The researchers in recent years have been collecting samples of S. aureus from pigs, farmworkers, farmworkers' family members, and community residents -- including children -- in the top pig-producing counties in North Carolina. For the study, they sequenced the DNA from some of these samples to determine the relation of the strains found in pigs and people. They found that the strains were very closely related, providing evidence for transmission between pigs and people. Most of the strains carried genes conferring resistance to multiple antibiotics."We found that these livestock-associated S. aureus strains had many genes that confer resistance to antimicrobial drugs commonly used in the U.S. industrialized pig production system," says study first author Pranay Randad, PhD, a postdoctoral researcher in the Bloomberg School's Department of Environmental Health and Engineering."These findings warrant future investigations into the transmission dynamics in nearby communities and disease burden associated with these strains in the United States," says study senior author Christopher Heaney, PhD, associate professor in the same department. Epidemiologists have long suspected that S. aureus and other bacteria are transmitted from humans to pigs on factory farms, and thereafter evolve antibiotic resistance within the pigs. The animals are routinely given antibiotics to prevent outbreaks in their dense concentrations on factory farms. The drug-resistant bacterial strains may then be transmitted back to humans, becoming a potentially serious source of disease.In recent years, Heaney and colleagues have been gathering S. aureus isolates from pigs and farmworkers at factory-scale pig farms in North Carolina, one of the leading pig-farming states. Their research has shown that livestock-associated strains of S. aureus, many of them antibiotic-resistant strains, can be found not only in pigs but also in farmworkers, their family members, and residents living nearby.For the new study they performed whole-genome sequencing on 49 of these S. aureus isolates to characterize these strains at the DNA level and get a more precise picture of their interrelatedness.One finding was that all these isolates, whether taken from humans or pigs, belonged to a grouping of S. aureus strains known as clonal complex 9 (CC9)."This CC9 is a novel and emerging subpopulation of S. aureus that not many people have been studying, apart from a few reports in Asia," Randad says.The researchers also determined from their analysis that the CC9 isolates from North Carolina were closely related, in many cases implying recent transmission between pigs and people. Moreover, virtually all of the isolates that appeared to be involved in transmission between pigs and humans were multidrug resistant, suggesting that diseases these isolates cause could be hard to treat.The scope of the study didn't include evaluating S. aureus-related disease among people in the affected communities, but one of the pig farmworkers who carried a CC9 isolate in their nose reported a recent skin infection."In other countries, such as in Europe, we see a high level of coordinated research on this topic from a public health perspective, with open access to collect bacterial isolates from pigs raised on factory farms, but so far in the U.S. not as much is being done," Randad says.Support for the study was provided by the Sherrilyn and Ken Fisher Center for Environmental Infectious Diseases Discovery Program at the Johns Hopkins University School of Medicine; the GRACE Communications Foundation; the National Institute for Occupational Safety and Health, the National Science Foundation, the National Institute of Allergy and Infectious Diseases, and the National Institute of Environmental Health Sciences, among other funding sources.
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Agriculture & Food
| 2,021 |
March 4, 2021
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https://www.sciencedaily.com/releases/2021/03/210304145419.htm
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Key factor identified that makes worms feel full after a good meal
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In nematode worms, a key controller allows the worm to sense when it needs food and when it feels full, and then changes its behavior accordingly. Jennifer Tullet of the University of Kent and colleagues report these new findings in a paper published March 4th in
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Deciding when and how much to eat is crucial for maintaining health and to preventing overeating. Our bodies take in complex molecular signals from our nervous, physiological and metabolic systems, which tell us when we're hungry and when to stop eating, but how these signals work are not yet well understood. Tullet and her colleagues used the nematode worm The new study suggests the possibility that a similar transcription factor in humans regulates food-sensing and the feeling of being full. Instead of SKN-1B, mammals have NF-E2 related transcription factors, or Nrfs, which scientists think function in metabolism and the process of converting food nutrients into energy. Nrfs also play a role in the phenomenon where animals live longer when they restrict their calories. If future research confirms the role of Nrfs in signaling fullness, then Nrfs may be a new target for developing drugs that control overeating.The authors add, "We are really excited about this work, understanding the neuroendocrinology of eating and sleeping is so important to lifelong health and wellbeing."
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Agriculture & Food
| 2,021 |
March 4, 2021
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https://www.sciencedaily.com/releases/2021/03/210304112437.htm
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Protein discovery could help enable eco-friendly fungicides
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New research reveals an essential step in scientists' quest to create targeted, more eco-friendly fungicides that protect food crops.
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Scientists have known for decades that biological cells manufacture tiny, round structures called extracellular vesicles. However, their pivotal roles in communication between invading microorganisms and their hosts were recognized only recently.UC Riverside geneticist Hailing Jin and her team found plants use these vesicles to launch RNA molecules at fungal invaders, suppressing the genes that make the fungi dangerous."These vesicles shuttle small RNAs between cells, like tiny Trojan horses with weapons hidden inside," said Jin, a professor of genetics and the Cy Mouradick Chair in the Department of Plant Pathology and Microbiology. "They can silence pathogenic fungal gene expression."Using extracellular vesicles and small RNAs has several advantages over conventional fungicides. They're more eco-friendly because they are similar to naturally occurring products. Eventually, they degrade and do not leave toxic residues in the soil. Also, Jin explained, this method of fighting fungi is less likely to breed drug-resistant pathogens.A sticking point for scientists in creating these fungicides has been figuring out how to load their desired small RNAs into the vesicles."We've wondered how these weaponized small RNAs get into the bubbles," Jin said. "Now, we think we have an answer."Her laboratory has identified several proteins that serve as binding agents, helping to select and load small RNAs into the vesicles. The lab's research is detailed in a new The Jin laboratory has been working for several years on the development of gene-silencing RNA fungicides. Work toward this goal led to the team's landmark discovery in 2013 that gene-silencing RNA messages can be sent from the fungal pathogen to the plant host to suppress host immunity. Later, the team learned small RNAs can move both ways -- from plants into pathogenic invader cells as well.In 2018, the team worked out that extracellular vesicles were the major delivery system for these small RNAs. They observed that Arabidopsis plants secrete extracellular vesicles into Botrytis cinerea, a fungus that causes grey mold disease and destroys millions of crops every year."This was the first example of a host using these vesicles to deliver small RNAs to another organism," Jin said. "Previously we saw movement of RNA, but didn't know how the small RNA are selected and transported."Now, she and her colleagues have identified several RNA-binding proteins in Arabidopsis that bind to specific small RNA molecules and load them into extracellular vesicles. This suggests the proteins play an important role in loading and stabilizing small RNAs in the vesicles. The finding can help increase the payload of gene-silencing RNAs that make it into vesicles and enhance the efficiency of disease control.Some scientists have taken inspiration from the RNA communication in plant vesicles to design human therapies. For example, some are attempting to load anti-cancer RNAs and drugs into extracellular vesicles in fruits or vegetables, so people can eat or drink them. Jin is hopeful that her lab's discovery can aid these efforts.
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Agriculture & Food
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