Climate change and air pollution will combine to curb food supplies

Many studies have shown the potential for global climate change to cut food supplies. But these studies have, for the most part, ignored the interactions between increasing temperature and air pollution — specifically ozone pollution, which is known to damage crops.A new study involving researchers at MIT shows that these interactions can be quite significant, suggesting that policymakers need to take both warming and air pollution into account in addressing food security.The study looked in detail at global production of four leading food crops — rice, wheat, corn, and soy — that account for more than half the calories humans consume worldwide. It predicts that effects will vary considerably from region to region, and that some of the crops are much more strongly affected by one or the other of the factors: For example, wheat is very sensitive to ozone exposure, while corn is much more adversely affected by heat.The research was carried out by Colette Heald, an associate professor of civil and environmental engineering (CEE) at MIT, former CEE postdoc Amos Tai, and Maria van Martin at Colorado State University. Their work is described this week in the journal Nature Climate Change.Heald explains that while it’s known that both higher temperatures and ozone pollution can damage plants and reduce crop yields, “nobody has looked at these together.” And while rising temperatures are widely discussed, the impact of air quality on crops is less recognized.The effects are likely to vary widely by region, the study predicts. In the United States, tougher air-quality regulations are expected to lead to a sharp decline in ozone pollution, mitigating its impact on crops. But in other regions, the outcome “will depend on domestic air-pollution policies,” Heald says. “An air-quality cleanup would improve crop yields.”Overall, with all other factors being equal, warming may reduce crop yields globally by about 10 percent by 2050, the study found. But the effects of ozone pollution are more complex — some crops are more strongly affected by it than others — which suggests that pollution-control measures could play a major role in determining outcomes.Ozone pollution can also be tricky to identify, Heald says, because its damage can resemble other plant illnesses, producing flecks on leaves and discoloration.Potential reductions in crop yields are worrisome: The world is expected to need about 50 percent more food by 2050, the authors say, due to population growth and changing dietary trends in the developing world. So any yield reductions come against a backdrop of an overall need to increase production significantly through improved crop selections and farming methods, as well as expansion of farmland.While heat and ozone can each damage plants independently, the factors also interact. For example, warmer temperatures significantly increase production of ozone from the reactions, in sunlight, of volatile organic compounds and nitrogen oxides. …

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Changes in agriculture increase high river flow rates

Just as a leaky roof can make a house cooler and wetter when it’s raining as well as hotter and dryer when it’s sunny, changes in land use can affect river flow in both rainy and dry times, say two University of Iowa researchers.While it may be obvious that changes in river water discharge across the U.S. Midwest can be related to changes in rainfall and agricultural land use, it is important to learn how these two factors interact in order to get a better understanding of what the future may look like, says Gabriele Villarini, UI assistant professor of civil and environmental engineering, assistant research engineer at IIHR — Hydroscience & Engineering and lead author of a published research paper on the subject.”We wanted to know what the relative impacts of precipitation and agricultural practices played in shaping the discharge record that we see today,” he says. “Is it an either/or answer or a much more nuanced one?”By understanding our past we are better positioned in making meaningful statements about our future,” he says.The potential benefits of understanding river flow are especially great in the central United States, particularly Iowa, where spring and summer floods have hit the area in 1993, 2008, 2013 and 2014, interrupted by the drought of 2012. Large economic damage and even loss of life have resulted, says co-author Aaron Strong, UI assistant professor in the Department of Urban and Regional Planning and with the Environmental Policy Program at the UI Public Policy Center.”What is interesting to note,” says Strong, “is that the impacts, in terms of flooding, have been exacerbated. At the same time, the impacts of drought, for in-stream flow, have been mitigated with the changes in land use composition that we have seen over the last century.”In order to study the effect of changes in agricultural practices on Midwest river discharge, the researchers focused on Iowa’s Raccoon River at Van Meter, Iowa. The 9,000-square-kilometer watershed has the advantage of having had its water discharge levels measured and recorded daily for most of the 20th century right on up to the present day. (The study focused on the period 1927-2012). During that period, the number of acres used for corn and soybean production greatly increased, roughly doubling over the course of the 20th century.Not surprisingly, they found that variability in rainfall is responsible for most of the changes in water discharge volumes.However, the water discharge rates also varied with changes in agricultural practices, as defined by soybean and corn harvested acreage in the Raccoon River watershed. In times of flood and in times of drought, water flow rates were exacerbated by more or less agriculture, respectively. The authors suggest that although flood conditions may be exacerbated by increases in agricultural production, this concern “must all be balanced by the private concerns of increased revenue from agricultural production through increased cultivation.””Our results suggest that changes in agricultural practices over this watershed — with increasing acreage planted in corn and soybeans over time — translated into a seven-fold increase in rainfall contribution to the average annual maximum discharge when we compare the present to the 1930s,” Villarini says.The UI research paper, “Roles of climate and agricultural practices in discharge changes in an agricultural watershed in Iowa,” can be found in the April 15 online edition of Agriculture, Ecosystems & Environment.Story Source:The above story is based on materials provided by University of Iowa. …

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Carbon loss from soil accelerating climate change

Research published in Science today found that increased levels of carbon dioxide in the atmosphere cause soil microbes to produce more carbon dioxide, accelerating climate change.Two Northern Arizona University researchers led the study, which challenges previous understanding about how carbon accumulates in soil. Increased levels of CO2 accelerate plant growth, which causes more absorption of CO2 through photosynthesis.Until now, the accepted belief was that carbon is then stored in wood and soil for a long time, slowing climate change. Yet this new research suggests that the extra carbon provides fuel to microorganisms in the soil whose byproducts (such as CO2) are released into the atmosphere, contributing to climate change.”Our findings mean that nature is not as efficient in slowing global warming as we previously thought,” said Kees Jan van Groenigen, research fellow at the Center for Ecosystem Science and Society at NAU and lead author of the study. “By overlooking this effect of increased CO2 on soil microbes, models used by the Intergovernmental Panel on Climate Change may have overestimated the potential of soil to store carbon and mitigate the greenhouse effect.”In order to better understand how soil microbes respond to the changing atmosphere, the study’s authors utilized statistical techniques that compare data to models and test for general patterns across studies. They analyzed published results from 53 different experiments in forests, grasslands and agricultural fields around the world. These experiments all measured how extra CO2 in the atmosphere affects plant growth, microbial production of carbon dioxide, and the total amount of soil carbon at the end of the experiment.”We’ve long thought soils to be a stable, safe place to store carbon, but our results show soil carbon is not as stable as we previously thought,” said Bruce Hungate, director of the Center for Ecosystem Science and Society at NAU and study author. “We should not be complacent about continued subsidies from nature in slowing climate change.”Story Source:The above story is based on materials provided by Northern Arizona University. Note: Materials may be edited for content and length.

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Temperature fluctuations: Atlantic Ocean dances with the sun and volcanoes

Natural fluctuations in the ocean temperature in the North Atlantic have a significant impact on the climate in the northern hemisphere. These fluctuations are the result of a complex dance between the forces of nature, but researchers at Aarhus University can now show that solar activity and the impact of volcanic eruptions have led this dance during the last two centuries.Imagine a ballroom in which two dancers apparently keep in time to their own individual rhythm. The two partners suddenly find themselves moving to the same rhythm and, after a closer look, it is clear to see which one is leading.It was an image like this that researchers at Aarhus University were able to see when they compared studies of solar energy release and volcanic activity during the last 450 years, with reconstructions of ocean temperature fluctuations during the same period.The results actually showed that during the last approximately 250 years — since the period known as the Little Ice Age — a clear correlation can be seen where the external forces, i.e. the Sun’s energy cycle and the impact of volcanic eruptions, are accompanied by a corresponding temperature fluctuation with a time lag of about five years.In the previous two centuries, i.e. during the Little Ice Age, the link was not as strong, and the temperature of the Atlantic Ocean appears to have followed its own rhythm to a greater extent.The results were recently published in the scientific journal Nature Communications.In addition to filling in yet another piece of the puzzle associated with understanding the complex interaction of the natural forces that control the climate, the Danish researchers paved the way for linking the two competing interpretations of the origin of the oscillation phenomenon.Temperature fluctuations discovered around the turn of the millenniumThe climate is defined on the basis of data including mean temperature values recorded over a period of thirty years. Northern Europe thus has a warm and humid climate compared with other regions on the same latitudes. This is due to the North Atlantic Drift (often referred to as the Gulf Stream), an ocean current that transports relatively warm water from the south-west part of the North Atlantic to the sea off the coast of Northern Europe.Around the turn of the millennium, however, climate researchers became aware that the average temperature of the Atlantic Ocean was not entirely stable, but actually fluctuated at the same rate throughout the North Atlantic. This phenomenon is called the Atlantic Multidecadal Oscillation (AMO), which consists of relatively warm periods lasting thirty to forty years being replaced by cool periods of the same duration. The researchers were able to read small systematic variations in the water temperature in the North Atlantic in measurements taken by ships during the last 140 years.Although the temperature fluctuations are small — less than 1C — there is a general consensus among climate researchers that the AMO phenomenon has had a major impact on the climate in the area around the North Atlantic for thousands of years, but until now there has been doubt about what could cause this slow rhythm in the temperature of the Atlantic Ocean. One model explains the phenomenon as internal variability in the ocean circulation — somewhat like a bathtub sloshing water around in its own rhythm. …

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Deep ocean current may slow due to climate change

Far beneath the surface of the ocean, deep currents act as conveyer belts, channeling heat, carbon, oxygen and nutrients around the globe.A new study by the University of Pennsylvania’s Irina Marinov and Raffaele Bernardello and colleagues from McGill University has found that recent climate change may be acting to slow down one of these conveyer belts, with potentially serious consequences for the future of the planet’s climate.”Our observations are showing us that there is less formation of these deep waters near Antarctica,” Marinov said. “This is worrisome because, if this is the case, we’re likely going to see less uptake of human produced, or anthropogenic, heat and carbon dioxide by the ocean, making this a positive feedback loop for climate change.”Marinov is an assistant professor in Penn’s School of Arts and Sciences’ Department of Earth and Environmental Science, while Bernardello was a postdoctoral investigator in the same department and has just moved to the National Oceanography Centre in the United Kingdom. They collaborated with Casimir de Lavergne, Jaime B. Palter and Eric D. Galbraith of McGill University on the study, which was published in Nature Climate Change.Oceanographers have noticed that Antarctic Bottom Waters, a massive current of cold, salty and dense water that flows 2,000 meters under the ocean’s surface from near the Antarctic coast toward the equator has been shrinking in recent decades. This is cause for concern, as the current is believed to “hide” heat and carbon from the atmosphere. The Southern Ocean takes up approximately 60 percent of the anthropogenic heat produced on Earth and 40 to 50 percent of the anthropogenic carbon dioxide.”The Southern Ocean is emerging as being very, very important for regulating climate,” Marinov said.Along with colleagues, Marinov used models to discern whether the shrinking of the Antarctic Bottom Waters could be attributed to anthropogenic climate change.They looked to an unusual phenomenon that had been observed from satellite images taken between 1974 and 1976. The images revealed a large ice-free area within the Weddell Sea. Called a polynya, this opening in the sea ice forms when warm water of North Atlantic origin is pushed up toward the Southern Ocean’s surface. In a separate process, brine released during the sea-ice formation process produces a reservoir of cold, salty waters at the surface of the Weddell Sea. …

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Global food trade can alleviate water scarcity

International trade of food crops led to freshwater savings worth 2.4 billion US-Dollars in 2005 and had a major impact on local water stress. This is shown in a new study by the Potsdam Institute for Climate Impact Research. Trading food involves the trade of virtually embedded water used for production, and the amount of that water depends heavily on the climatic conditions in the production region: It takes, for instance, 2.700 liters of water to produce 1 kilo of cereals in Morocco, while the same kilo produced in Germany uses up only 520 liters. Analyzing the impact of trade on local water scarcity, our scientists found that it is not the amount of water used that counts most, but the origin of the water. While parts of India or the Middle East alleviate their water scarcity through importing crops, some countries in Southern Europe export agricultural goods from water-scarce sites, thus increasing local water stress.”Agriculture accounts for 70 percent of our global freshwater consumption and therefore has a huge potential to affect local water scarcity,” lead author Anne Biewald says. The amount of water used in the production of agricultural export goods is referred to as virtual water trade. So far, however, the concept of virtual water could not identify the regional water source, but used national or even global averages instead. “Our analysis shows that it is not the amount of water that matters, but whether global food trade leads to conserving or depleting water reserves in water-scarce regions,” Biewald says.Combining biophysical simulations of the virtual water content of crop production with agro-economic land-use and water-use simulations, the scientists were able for the first time to determine the positive and negative impacts on water scarcity through international trade of crops, livestock and feed. The effects were analyzed with high resolution on a subnational level to account for large countries like India or the US with different climatic zones and relating varying local conditions regarding water availability and water productivity. Previously, these countries could only be evaluated through national average water productivity. …

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Dry future climate could reduce orchid bee habitat

During Pleistocene era climate changes, neotropical orchid bees that relied on year-round warmth and wet weather found their habitats reduced by 30 to 50 percent, according to a Cornell University study that used computer models and genetic data to understand bee distributions during past climate changes.In previous studies, researchers have tracked male and female orchid bees and found that while females stay near their nests, male orchid bees travel, with one study concluding they roam as far as 7 kilometers per day. These past findings, corroborated by genetic data in the current study, reveal that males are more mobile than females.The study, published online in the journal Molecular Ecology, has important implications for future climate changes.”The dataset tells us that if the tendency is to have lower precipitation in combination with deforestation, the suitable habitat for the bees is going to be reduced,” said Margarita Lpez-Uribe, the paper’s first author and a graduate student at Cornell.The good news is that since male orchid bees habitually travel far, they can keep bee populations connected and healthy.”The males are mediating genetic exchange among populations, maintaining connectivity in spite of fragmentation of habitats,” said Lpez-Uribe. “This is a possible mechanism bees could use to ameliorate the negative impacts of population isolation resulting from future climate changes and deforestation.”By looking at current climate and bee distributions, Lpez-Uribe and colleagues assessed parameters of climate conditions that each of three bee species within the genus Eulaema could tolerate physiologically, including temperature and precipitation variability. She found that one of the three species, Eulaema cingulata, was three times more tolerant to a variety of climatic conditions.By proceeding with the caveat that physiological tolerance has remained constant — species tend to be evolutionarily conservative about shifting their niches — the researchers used computer models to simulate past bee distributions based on climate conditions in the Pleistocene. The results showed that in the past, during periods when the neotropics had lowered precipitation, each species experienced significant reduction in suitable habitat, with E. cingulata maintaining the largest geographical ranges.Climate and ecological niche computer model simulations were closely matched by genetic data of the two less-tolerant orchid bee species. The genetic data included mitochondrial markers, which are only inherited from females, and nuclear markers, which come from males and females. The mitochondrial DNA showed that individual bees in one geographic area were more closely related to each other than to bees from other areas. The findings suggest the maternal lines of these bees remained in the area and shared the same pools of DNA over time. But the bi-parental nuclear DNA showed more variation between individuals within an area, offering evidence that males traveled and shared their DNA with other regional groups.Orchid bees live in the neotropics, an ecozone that includes part of South and Central America, the Mexican lowlands and the Caribbean islands. …

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Climate change will reduce crop yields sooner than thought

A study led by the University of Leeds has shown that global warming of only 2C will be detrimental to crops in temperate and tropical regions, with reduced yields from the 2030s onwards.Professor Andy Challinor, from the School of Earth and Environment at the University of Leeds and lead author of the study, said: “Our research shows that crop yields will be negatively affected by climate change much earlier than expected.””Furthermore, the impact of climate change on crops will vary both from year-to-year and from place-to-place — with the variability becoming greater as the weather becomes increasingly erratic.”The study, published today by the journal Nature Climate Change, feeds directly into the Working Group II report of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, which is due to be published at the end of March 2014.In the study, the researchers created a new data set by combining and comparing results from 1,700 published assessments of the response that climate change will have on the yields of rice, maize and wheat.Due to increased interest in climate change research, the new study was able to create the largest dataset to date on crop responses, with more than double the number of studies that were available for researchers to analyze for the IPCC Fourth Assessment Report in 2007.In the Fourth Assessment Report, scientists had reported that regions of the world with temperate climates, such as Europe and most of North America, could withstand a couple of degrees of warming without a noticeable effect on harvests, or possibly even benefit from a bumper crop.”As more data have become available, we’ve seen a shift in consensus, telling us that the impacts of climate change in temperate regions will happen sooner rather than later,” said Professor Challinor.The researchers state that we will see, on average, an increasingly negative impact of climate change on crop yields from the 2030s onwards. The impact will be greatest in the second half of the century, when decreases of over 25% will become increasingly common.These statistics already account for minor adaptation techniques employed by farmers to mitigate the effects of climate change, such as small adjustments in the crop variety and planting date. Later in the century, greater agricultural transformations and innovations will be needed in order to safeguard crop yields for future generations.”Climate change means a less predictable harvest, with different countries winning and losing in different years. The overall picture remains negative, and we are now starting to see how research can support adaptation by avoiding the worse impacts,” concludes Professor Challinor.Story Source:The above story is based on materials provided by University of Leeds. Note: Materials may be edited for content and length.

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Serpentine ecosystems shed light on nature of plant adaptation, speciation

Plants that live in unusual soils, such as those that are extremely low in essential nutrients, provide insight into the mechanisms of adaptation, natural selection, and endemism. A seminal paper by Arthur Kruckeberg from 1951 on serpentine plant endemism has served as a solid bedrock foundation for future research on the link between natural selection and speciation. A recent article in the American Journal of Botany focuses on how this paper has influenced subsequent research on local adaptation, evolutionary pathways, and the relationship between climate, soils, and endemism.In the latest in a series of AJB Centennial Review papers, AJB Anacker (University of California, Davis) examines the impact that Kruckeberg’s 1951 AJB paper has had on our subsequent understanding of plant evolution and ecology.Kruckeberg’s classic paper reported on reciprocal transplant experiments, in which he made several generalizations about plant competition, local adaptation, and speciation. Kruckeberg showed that the strong selective pressures of serpentine soils — characterized by low amounts of essential nutrients and water, and high in heavy metals — can lead to the formation of soil ecotypes (genetically distinct plant varieties), representing a possible first step in the evolution of serpentine endemism (e.g., plants that are only found on serpentine type soils). These important initial findings spurred subsequent research on determining plant traits (from molecular to organismal) that underlie serpentine adaptation.Anacker draws attention to a second significant contribution of Kruckeberg’s paper — researching the historic origins of endemic species, such as those found in serpentine soils. Anacker explains that endemic species are thought to originate in two ways: neoendemics are species that have formed relatively recently via nearby progenitor taxa, and paleoendemics are species that formed following habitat-specific population extirpation. Kruckeberg viewed serpentine ecotypes as representing the first step along the path of paleoendemism. While this stimulated much research in this area, Anacker points out that several serpentine endemics appear to have arisen from nearby progenitor taxa, and thus the neoendemic pathway is also likely important.Interestingly, Kruckeberg’s experiments also showed that many serpentine ecotypes actually performed better on the non-serpentine soils than on serpentine soils, which begs the question of why serpentine-adapted plants are not also found on non-serpentine soils. Anacker points out that Kruckeberg was one of the first to indicate that competition may play a key role in serpentine specialization. He also highlights recent research indicating that serpentine species are typically slow-growing stress tolerators rather than fast-growing competitive dominants, and their adaptations for being more drought-tolerant puts them at a disadvantage in soils where water and nutrients are not limiting.While serpentine ecosystems are special and unique environments, Kruckeberg and subsequent researchers have shown how important these systems are for shedding light on broader aspects of plant ecology and evolution.The 1951 paper can be accessed online at: http://www.jstor.org/discover/10.2307/2438248?uid=3739448&uid=2&uid=3737720&uid=4&sid=21103728973903Story Source:The above story is based on materials provided by American Journal of Botany. …

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The rise of spring allergies: Fact or fiction?

The spring 2014 allergy season could be the worst yet, or at least that is what you might hear. Every year is coined as being the worst for allergy sufferers, but are spring allergies really on the rise?”A number of factors, such as weather patterns, predict how intense the spring allergy season will be,” said allergist Michael Foggs, MD, president of the American College of Allergy, Asthma and Immunology (ACAAI). “While allergies are on the rise, affecting more and more Americans every year, each spring isn’t necessarily worse than the last.”According to ACAAI, 23.6 million Americans were diagnosed with hay fever in the last year. The prevalence of allergies is surging upward, with as many as 30 percent of adults and up to 40 percent of children having at least one allergy.”With more people being affected by seasonal allergies, it may seem like every year is the worst yet for sufferers,” said Dr. Foggs. “But in reality, there might just be more people complaining about symptoms.”Following are factors that influence the severity of allergy season, along with some explanations about why more Americans are being diagnosed with allergies.• Climate Change – Recent studies have shown pollen levels gradually increase every year. Part of the reason for this is due to the changing climate. The warmer temperatures and mild winters cause plants to begin producing and releasing pollen earlier, making the spring allergy season longer. Rain can promote plant and pollen growth, while wind accompanying rainfall can stir pollen and mold into the air, heightening symptoms. The climate is not only responsible for making the allergy season longer and symptoms more bothersome, but may also be partially to blame for the rise in allergy sufferers.• Priming Effect – A mild winter can trigger an early release of pollen from trees. …

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Can the solution to climate change help eliminate poverty?

It is clear that climate change and poverty are two separate problems that affect all corners of the world, but can the solution to one help eliminate the other? Richard Munang and Jessica Andrews, authors of “Harnessing Ecosystem-Based Adaptation: To Address the Social Dimensions of Climate Change,” published in Environment: Science and Policy for Sustainable Development, think that we can.Ecosystem-Based Adaptation (EbA) is becoming more widely recognized as a possible solution to addressing climate change. “EbA is the use of biodiversity and ecosystem services as part of an overall adaptation to help people and communities adapt to the negative effects of climate change at local, regional, and global levels.” It works by providing sustainable social benefits for a local community within climate change adaptation practices. This idea understands the relationship and interconnectivity between many different facets of life; ecological, social/cultural, economic, and institutional.EbA is built to successfully implement sustained social and environmental achievements. Developing a community’s resilience in the face of climate change impacts improves the wellness of the entire ecosystem. “EbA can accelerate income gains, improve health, and secure food production, all while ensuring the sustainable development of local resources.” Munang and Andrews provide examples where this program has been successful. In Togo, Africa, EbA aided in the revitalization of water reservoirs, as well as cereal and vegetable production in the savannah region, directly benefiting women and youth groups. The extraordinary and integral component of this program is the collaboration between nongovernmental and civil society organizations (NGOs and CSOs, respectively) and the local community. This resulted in improved access to water, an array of social benefits, and a trained community competent to take an active role in future resilience efforts.However, there are some problems. The success of EbA depends largely on the involvement of the local community in the planning and implementation process, while also taking into consideration the overall political context and land use conflicts. …

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Climate change: Improving heat tolerance in trees

Is it possible to improve tolerance of trees to high temperatures and other types of stress derived of climate change? A research group of the Universidad Politcnica de Madrid (UPM), led by Luis Gmez, a professor of the Forestry School and the Centre for Plant Biotechnology and Genomics (CBGP), is studying the tolerance of trees using molecular and biotechnological tools. The research work was published in the last issue of the journal Plant Physiology.The obtained poplars in this project, with the collaboration of the Universidad de Mlaga, are significantly more tolerant to high temperatures than the control trees. These trees are also more tolerant to drought, to the presence of weed-killer, to in vitro and ex vitro crops, to contamination and other ways of abiotic stress that have an applied interest for forestry. This work is a continuation of a project started by of a research team of the UPM a decade ago. This study focuses on mechanisms that plant cells use to protect themselves from stress factors.Due to the human pressure on forests, the Food and Agriculture Organization of the United Nations (FAO) is promoting intensive plantations as an alternative to meet the global demand of wood and other products. Besides, plantations have social and economic benefits (job creation, wealth and rural development). This model change has significant ecological consequences.The role of forests is essential for climate change mitigation and biodiversity preservation, amongst others. A documentary “El Bosque Protector,” co-produced by the UPM and available on “A la Carta” of RTVE shows the result of this study. Tree farming plantations as a realistic alternative will be possible if the current yield significantly increases. …

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Crop species may be more vulnerable to climate change than we thought

A new study by a Wits University scientist has overturned a long-standing hypothesis about plant speciation (the formation of new and distinct species in the course of evolution), suggesting that agricultural crops could be more vulnerable to climate change than was previously thought.Unlike humans and most other animals, plants can tolerate multiple copies of their genes — in fact some plants, called polyploids, can have more than 50 duplicates of their genomes in every cell. Scientists used to think that these extra genomes helped polyploids survive in new and extreme environments, like the tropics or the Arctic, promoting the establishment of new species.However, when Dr Kelsey Glennon of the Wits School of Animal, Plant and Environmental Sciences and a team of international collaborators tested this long-standing hypothesis, they found that, more often than not, polyploids shared the same habitats as their close relatives with normal genome sizes.”This means that environmental factors do not play a large role in the establishment of new plant species and that maybe other factors, like the ability to spread your seeds to new locations with similar habitats, are more important,” said Glennon.”This study has implications for agriculture and climate change because all of our important crops are polyploids and they might not be much better at adapting to changing climate than their wild relatives if they live in similar climates.”Glennon’s study also provides an alternative explanation for why plants are so diverse in places like the Cape where the climate has been stable for hundreds of thousands of years. Although her study examined plant species from North America and Europe only, she is looking forward to testing her hypotheses using South African plants.Glennon’s paper has been published in Ecology Letters.Story Source:The above story is based on materials provided by Wits University. Note: Materials may be edited for content and length.

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Seal evolution: Sexual dimorphism in pinnipeds arose around 27 million years ago as climate changed

In the world of science, one of the most exciting things a researcher can do is pin down an answer to a widely asked question. This experience came early for Carleton University graduate Thomas Cullen, who made a discovery about pinnipeds — the suborder that makes up seals, sea lions and walruses — while doing research for his Master’s degree under the supervision of Canadian Museum of Nature palaeontologist Dr. Natalia Rybczynski.His discovery, published today in the journal Evolution, relates to sexual dimorphism (a large variance in size between males and females), in a variety of pinniped species. Males in many species of pinnipeds are often much larger than their female counterparts, in some cases more than twice as large, and this has implications for how they mate and behave.Dimorphic pinnipeds such as the Steller’s Sea Lion and Northern Fur Seal typically mate in a harem, with one male pinniped presiding over a larger community of female mates. This behavior is not typically seen in non-dimorphic pinnipeds such as the Ringed Seal, and so sexual dimorphism is intimately linked with mating style.Researchers have long puzzled over both why sexual dimorphism exists in many pinniped species and when this trait evolved. When Cullen examined fossils of an extinct pinniped with Rybczynski, he discovered an incontrovertible answer to the question of when. He was able to examine it there before analyzing the data at Carleton in a lab headed by his other thesis supervisor, Prof. Claudia Schrder-Adams.Skull of Enaliarctos emlongi, an early pinniped ancestor. Cullen examined and analyzed the characteristics of this fossil for his study on the evolution of sexual dimorphism in pinnipeds.”We were examining a fossil of a pinniped that was previously thought to be a juvenile, but we looked at it again and found that, based on its skull structure, it was likely an adult,” says Cullen. This discovery, coupled with analyses comparing this fossil to others of the same species as well as modern dimorphic species, proved that the fossil belonged to a sexually dimorphic species.The fossil in question, the skull of an early pinniped ancestor called Enaliarctos emlongi, was discovered in the late 1980s off the coast of Oregon. …

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Extreme weather images in the media cause fear and disengagement with climate change

The paper ‘ Images of Extreme Weather: Symbolising Human Responses to Climate Change’, by Brigitte Nerlich & Rusi Jaspal, published in Science as Culture, reveals that extreme weather images represent human suffering and loss. They are iconic of climate change and are symbols of its natural impacts.Reporting on extreme weather has increased over the last few years. In the past social scientists, and media and communication analysts have studied how climate change is depicted in the text of media and social media. While researchers have become increasingly interested in climate change images, they have not yet studied them with respect to symbolising certain emotions.The International Panel on Climate Change (IPCC) published a draft report on extreme weather and climate change adaptation. The report was covered in the news and illustrated with images. Some of these depicted ‘extreme weather’, in particular with relation to floods, droughts and heat waves, hurricanes and ice/sea-level rise.Researchers studied images published in the news to illustrate their coverage of the IPCC report. They used visual thematic analysis, examining the way they might symbolise certain emotional responses, such as compassion, fear, guilt, vulnerability, helpless, courage or resilience.Results showed that images of flooding displays people in the developing world ‘getting on with it’. It portrays individuals accustomed to flooding and that they can overcome the extreme weather. The images showed cheerful behaviour of those who are affected by flooding; lack of victimhood; engagement in their day-to-day activities and communal aspects of coping with flooding.New research has shown that images of extreme weather in the media create negative emotional meanings and might lead to disengagement with the issue of climate change. The images symbolised fear, helplessness and vulnerability and, in some cases, guilt and compassion. …

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Arctic biodiversity under serious threat from climate change

Unique and irreplaceable Arctic wildlife and landscapes are crucially at risk due to global warming caused by human activities according to the Arctic Biodiversity Assessment (ABA), a new report prepared by 253 scientists from 15 countries under the auspices of the Conservation of Arctic Flora and Fauna (CAFF), the biodiversity working group of the Arctic Council.”An entire bio-climatic zone, the high Arctic, may disappear. Polar bears and the other highly adapted organisms cannot move further north, so they may go extinct. We risk losing several species forever,” says Hans Meltofte of Aarhus University, chief scientist of the report.From the iconic polar bear and elusive narwhal to the tiny Arctic flowers and lichens that paint the tundra in the summer months, the Arctic is home to a diversity of highly adapted animal, plant, fungal and microbial species. All told, there are more than 21,000 species.Maintaining biodiversity in the Arctic is important for many reasons. For Arctic peoples, biodiversity is a vital part of their material and spiritual existence. Arctic fisheries and tourism have global importance and represent immense economic value. Millions of Arctic birds and mammals that migrate and connect the Arctic to virtually all parts of the globe are also at risk from climate change in the Arctic as well as from development and hunting in temperate and tropical areas. Marine and terrestrial ecosystems such as vast areas of lowland tundra, wetlands, mountains, extensive shallow ocean shelves, millennia-old ice shelves and huge seabird cliffs are characteristic to the Arctic. These are now at stake, according to the report.”Climate change is by far the worst threat to Arctic biodiversity. Temperatures are expected to increase more in the Arctic compared to the global average, resulting in severe disruptions to Arctic biodiversity some of which are already visible,” warns Meltofte.A planetary increase of 2 C, the worldwide agreed upon acceptable limit of warming, is projected to result in vastly more heating in the Arctic with anticipated temperature increases of 2.8-7.8 C this century. …

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Meeting the eye-witnesses of ocean change

Members of the German research network BIOACID (Biological Impacts of Ocean Acidification) are developing a model that links ecosystem changes triggered by ocean acidification and climate change with their economic and societal consequences. Workshops and interviews with stakeholders from the Norwegian fishing industry and tourism sector, the government and environmental organisations help them to identify key aspects for their assessment.During the past ten years, scientists have learned a lot about the effects of ocean acidification on marine ecosystems. It has become obvious that with rising carbon dioxide emissions from human activities, oceans absorb larger amounts of this greenhouse gas and become more acidic. The increase of acidity, rising water temperatures and other stressors may alter marine ecosystems dramatically — with consequences for economy and society.Do stakeholders of the economic sectors which depend on the sea already observe signs of ocean change? Which are their most urgent questions towards science? Within the framework of the German research network BIOACID (Biological Impacts of Ocean Acidification), scientists from the University of Bremen investigated stakeholders’ state of knowledge and identified focal points for further research. Between March and November 2013, they held workshops and interviewed more than 30 Norwegian fishers, representatives from fishing associations, aquaculture, tourism, environmental organisations and governmental agencies. They aim to develop a model that yields insights into the overall impacts of ocean change for ecosystems and the services they provide to human societies.”Taking a systems view can help to analyse socio-economic impacts of ocean acidification and find ways to mitigate them and adapt to them,” Dr. Stefan Gling-Reisemann, researcher at the Sustainability Research Center (artec) at the University of Bremen explains. “This is why we connect stakeholders and scientists and adapt further research to the demands of society.” Norway was chosen because the fishing industry, a branch that is likely to be hit first by effects of climate change, plays a very important economic role there. …

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New maps reveal locations of species at risk as climate changes

In research published today in the journal Nature, CSIRO and an international team of scientists revealed global maps showing how fast and in which direction local climates are shifting. This new study points to a simpler way of looking at climatic changes and their likely effects on biodiversity.As climate change unfolds over the next century, plants and animals will need to adapt or shift locations to track their ideal climate.”The maps show areas where plants and animals may struggle to find a new home in a changing climate and provide crucial information for targeting conservation efforts,” CSIRO’s Dr Elvira Poloczanska said.The study analyzed 50 years of sea surface and land temperature data (1960-2009) and also investigated two future scenarios for marine environments (‘business as usual’ and a 1.75C temperature increase).The new maps show where new thermal environments are being generated and where existing environments may disappear.”The maps show us how fast and in which direction temperatures are shifting, and where climate migrants following them may hit barriers such as coastlines. Our work shows that climate migration is far more complex than a simple shift towards the poles,” ecological geographer with the project Kristen Williams said.”Across Australia, species are already experiencing warmer temperatures. In terrestrial habitats, species have started to seek relief by moving to higher elevations, or further south. However, some species of animals and plants cannot move large distances, and some not at all.”Species migration can have important consequences for local biodiversity. For example, the dry, flat continental interior of Australia is a hot, arid region where species already exist close to the margin of their thermal tolerances.Some species driven south from monsoonal northern Australia in the hope of cooler habitats may perish in that environment.”In the oceans, warming waters and a strengthening of the East Australian Current have mobilised the Long-spined Sea Urchin (Centrostephanus rodgersii), previously only found as far south as southern NSW, to invade the eastern Tasmania coast. This has resulted in the decline of giant kelp forests with knock-on effects for commercially-fished rock lobsters,” Dr Poloczanska said.CSIRO and University of Queensland’s Anthony Richardson said the study cannot be used as a sole guide as to what to do in the face of climate change.”Biological factors such as a species’ capacity to adapt and disperse need to be taken into consideration,” Professor Richardson said.”But in an unprecedented period of climate change, economic development and fast growing demand on an already pressured planet, we need to act fast to make sure as much of the world’s living resources survive that change.”Story Source:The above story is based on materials provided by CSIRO Australia. Note: Materials may be edited for content and length.

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Aquatic Insects – a tremendous potential for research on diversification

Inland waters cover less than 1% of Earth’s surface yet harbor 10% of all known animal species, 60% of them being aquatic insects. Nearly 100,000 species from 12 orders spend one or more life stages in freshwater. Still today, little is known on how this remarkable diversity arose. Scientists of the Biodiversity and Climate Research Centre (BiK-F), the Naturalis Biodiversity Center in Leiden and the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin therefore investigated the potential of aquatic insects for research on diversification. The results have now been published in the journal Annual Review of Entomology.Freshwaters cover less than 1% of Earth’s surface, but harbour 10% of all animal species. Six out of ten of currently known species are insects. In a recently published review an international team of researchers from the Biodiversity and Climate Research Centre (BiK-F), the Biodiversity Center in Leiden, and the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin analyzed how studying the vast diversity of aquatic insects may contribute to a better understanding of diversification processes.”Analyzing the reasons behind the disproportionately high degree of aquatic insect diversity relative to the little area covered by freshwaters may help us to better understand species diversification,” specifies Dr. Steffen Pauls, leader of a junior research group at the BiK-F and one of the authors of the review.All aquatic insect groups are the result of the invasion of freshwaters by terrestrial groups: “Although belonging to only 12 orders, aquatic insects may represent more than 50 separate invasions,” explains co-author Dr. Klaas-Douwe Dijkstra from the Naturalis Biodiversity Center Leiden. The ecology and habitat preferences of many aquatic insect groups have been intensively studied, due to their roles as disease vectors or bioindicators for water quality. …

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New maps highlight habitat corridors in the tropics

A team of Woods Hole Research Center (WHRC) scientists created maps of habitat corridors connecting protected areas in the tropics to incorporate biodiversity co-benefits into climate change mitigation strategies. Drs. Patrick Jantz, Scott Goetz, and Nadine Laporte describe their findings in an article entitled, “Carbon stock corridors to mitigate climate change and promote biodiversity in the tropics,” available online in the journal Nature Climate Change on January 26.Climate change and deforestation are changing tropical ecosystems, isolating organisms in protected areas that will change along with climate, threatening their survival. Nearly every animal and plant species requires travelling some distance for nutrition, reproduction and genetic diversity, but few conservation or climate mitigation strategies take the connections between conserved lands into account. These habitat corridors are essential for longer-term biodiversity conservation, while also providing opportunities for climate change mitigation in the form of carbon sequestration and avoiding emissions from deforestation.According to lead author Dr. Jantz, “Maintaining connectivity of forest ecosystems provides ecological and societal benefits ensuring long-term species survival and providing room for ecosystems to reorganize in response to climate change and protecting ecosystem services that people depend on.” Co-author Dr. Goetz sees corridors as “avenues for migration of flora and fauna” needed for their survival “under the climate change we’re already committed to.”The team used a high-resolution data set of vegetation carbon stock (VCS) to map 16,257 corridors through areas of the highest biomass between 5,600 protected areas in the tropics. For Dr. Jantz, “the VCS corridor approach informs global frameworks for land management based climate change mitigation by showing which forests contain significant carbon stocks and are important for tropical biodiversity.”Part of the study focused on the Legal Amazon, where the team used economic and biological information combining species richness and endemism with economic opportunity costs and deforestation threats to prioritize optimal corridors. For Dr. …

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