Rain is a defining characteristic of the Pacific Northwest. Most of that region gets over 30 inches a year, and some areas get over 200. But human-caused climate change may alter this, according to the results of a recent study. Increasing droughts in this normally rainy area spurred a team of scientists from the University of Pittsburgh to explore the region’s historical precipitation patterns. The scientists looked at lake bottom sediments in Washington state to determine how often droughts occurred, how long they lasted and how severe they were. The team then pieced together a 6,000-year timeline of precipitation and evaporation in the Pacific Northwest. The results, published last week in the Proceedings of the National Academy of Science, show that El Niño events off the coast of Ecuador drive much of the precipitation fluctuations in areas such as Washington and Oregon. And while droughts have occurred throughout the 6,000 years the scientists analyzed, the length and severity of these dry periods have increased in the last century,. The scientists suspect that rising ocean temperatures are driving these droughts—a stronger El Niño in the Pacific Ocean means less rain in the Pacific Northwest. As population and greenhouse gas production both increase, they warn that even this normally rainy area may end up short of water.
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From Keystone Species to Ecosystem Transformer: The Changing Role of Prairie Dogs on the Front Range12/3/2010 Prairie dogs have long been a natural agent of change for ecosystems in the American West. But paired with recent climate change and human development, they are now turning certain Boulder grasslands into small-scale dust bowls.
During a recent visit to Teller Farm Open Space near Boulder, Colo., Tim Seastedt, a University of Colorado prairie ecologist, described this desertification process to a group of graduate students. A recurring plague is the only thing keeping the prairie dog population in check, he said, but the rodents may no longer be so susceptible. “It’s impressive how they seem to persist,” Seastedt said. The prairie dog has historically been a keystone species in the prairie grassland ecosystem, helping to create suitable habitat for a variety of other species, including burrowing owls and black-tailed ferrets. But the prairie dog’s role, too, is changing. Seastedt now describes prairie dogs as “ecosystem transformers.” Under normal conditions, the rodents relocate their colonies frequently so they can graze the short grass prairie and move on before the grass is gone. But today’s increased temperatures, longer growing seasons, and wetter winters mean the grass is being displaced by leafy plants and shrubs—many of them non-native. According to Seastedt, "shrublands don't have the ecological service" of prairie grasslands. Not only are they less palatable for grazers, but they also cause increased wind erosion, which is becoming more common along the Front Range, including at Teller Farm. Even if the grass is greener on the other side of the fence or road, habitat fragmentation no longer allows prairie dogs to cross these barriers, so their colonies are denser and put more strain on the environment. The result is increased erosion and a loss of soil fertility, Seastedt said. The first reports of winter dust storms caused by prairie dog induced erosion came from Fort Collins in 2006 and have since been reported in Boulder with increasing frequency. The congested prairie dog colonies are also vulnerable to sylvatic plague, a non-native disease for which the animals have historically had little or no resistance. But the increasing frequency of survivors suggests prairie dogs are now developing immunity to the disease. Seastedt said the plague recurs approximately once every decade. Since the mid 90s, the plague has served as a convenient, if temporary, solution to the prairie dog overpopulation problem on the Front Range. Prairie dogs are simultaneously protected by the Colorado Division of Wildlife and considered a pest by the state’s Department of Agriculture. And they are a source of contentious debate for land managers and local residents alike. The City of Boulder Open Space & Mountain Parks manages prairie dog habitat within Boulder County. According to the 2009 Grassland Management Plan, that habitat consists of 5,200 acres in Boulder County and excludes tall grass prairies and the foothills. Another 5,000 are designated as Multiple Use Areas, which allow prairie dogs to colonize as long as they do not negatively impact the land’s other uses. In terms of a long-term solution for the evolving grasslands and their furry inhabitants, Seastedt said he has “yet to find one that’s win-win for all involved.” The 2004 Tsunami took the lives of 230,000 coastal residents in Asia, but mangrove forests saved thousands more.
Chandra Giri, a land change scientist with the U.S. Geological Survey, was intrigued. “I watched TV news reports six years ago showing lives and property saved by mangroves during the tsunami,” said Giri. “These trees really do have a role to play as a protective barrier against some natural disasters.” Mangroves, or salt-tolerant coastal forests, provide food, habitat and carbon storage, but their ability to safeguard against hurricanes, tsunamis and floods is less clear. Giri set out to assess the protective value of mangrove forests, but a lack of distribution data sent his team of international scientists looking at where mangrove forests are rather than what they do. The team’s high-resolution satellite-based map of global mangrove distribution, which was published in the Journal of Global Ecology and Biogeography this summer, is the first of its kind. It shows mangroves on about 53,000 square miles of earth’s surface—12 percent less than previously thought. This reduction, coupled with increasing threats to mangroves, is cause for conservation concern. According to Giri, “Thirty five percent of mangrove ecosystems disappeared between 1980 and 2000…due to agricultural expansion, urban development and shrimp farming.” Source: http://www.eurekalert.org/pub_releases/2010-10/nsfc-rot102810.php Stress typically has negative effects on human health, but stress in plants may actually prove beneficial to the health of the planet as well as its human inhabitants.
Based on observation, genetic studies and computer modeling, a group of scientists from the National Center for Atmospheric Research (NCAR) published a paper in Science Express Thursday stating that deciduous plants worldwide absorb about 36 percent more polluting chemicals, or oVOCs, than previously thought. “Plants clean our air to a greater extent that we had realized,” said Thomas Karl, an NCAR scientist and the lead author of the study. “They actively consume certain types of air pollution.” Oxygenated volatile organic compounds, or oVOCs, are a type of air polluting chemical with negative effects on both human health and the environment. When the plants in the study were under stress, in the form of physical wounds or exposure to irritants such as ozone pollution, they absorbed more oVOCs from the atmosphere. “As a response to various types of stress,” said Chhandak Basu, one of the study’s scientists from the University of Northern Colorado, “plants can actually adjust their metabolism and increase their uptake of atmospheric chemicals.” Source: http://nsf.gov/news/news_summ.jsp?cntn_id=117919&org=NSF&from=news The price tag on a forest in today’s global market is a reflection of the lumber or paper it can produce.
According to Daniel Bunker, though, a forest’s value should also include the ecological services it provides: clean water, climate regulation, biomedical prospects and wildlife protection, among others. “Because these latter services are typically not bought and sold,” said Bunker, an assistant professor in the New Jersey Institute of Technology’s Federated Department of Biology, “their value is often ignored by landowners and policymakers.” Bunker is one of 16 leading biodiversity scientists working to change this. The team’s most recent paper, “Ecosystem Services for 2020,” was published in Science magazine Friday, and encourages recognition of these ecological service values under the Convention on Biological Diversity (CBD). “By placing value on these and all services that biodiversity produces,” says Bunker, “we will be better positioned to conserve the biodiversity that we so clearly rely upon for human well- being." The scientists hope their recommendations will encourage signatory nations at the 10th Conference of the Parties—the meeting of CBD’s governing body in Nagoya, Japan this week—to make ambitious and achievable goals for their 2020 CBD targets. Source: http://www.eurekalert.org/pub_releases/2010-10/njio-nph101510.php As our climate warms, scientists expect evapotranspiration to follow suit. On a global scale, though, this apparently is not the case.
In an article published in Nature on Sunday, scientists said evapotranspiration—the movement of water from the land to the atmosphere—increased during the 80s and 90s, as warmer temperatures increased ocean evaporation and precipitation. But beginning in 1998, evapotranspiration actually slowed or stopped in much of the southern half of the globe. Soils in these areas have become drier and consequently release less water. The affected areas include both historically dry regions and tropical rainforests. "We didn't expect to see this shift in evapotranspiration over such a large area of the Southern Hemisphere," said Beverly Law, a professor of global change forest science at Oregon State University and co-author of the study. Scientists do not have enough historical data to determine if the change is due to natural variability or a long-term global trend, but the latter implies serious consequences. Less evapotranspiration means less global cooling, as well as more frequent and intense heat waves. This will also increase drought stress, lowering the productivity and carbon absorption of plants. Source: http://www.eurekalert.org/pub_releases/2010-10/osu-lt100110.php “Car. Bun. Seek. West. Race. Shun.”
“Carbon Sequestration.” Both phrases say the same thing, but the latter is far more efficient. Similarly, both ordinary plants and genetically modified plants sequester carbon, but scientists at the Lawrence Berkeley and Oak Ridge National Laboratories assert that the latter can now be far more efficient. The UN defines carbon sequestration as “the process of removing carbon from the atmosphere and storing it in a reservoir. “ Plants are a natural carbon reservoir. During photosynthesis they incorporate atmospheric carbon into their biomass. This long-lived form of carbon eventually ends up in the soil and can remain out of circulation for hundreds of years. The study was published Friday in the October issue of BioScience, and included four strategies for boosting biological carbon sequestration through the genetic modification of plants: 1. Improving the light absorption efficiency of plants 2. Increasing the amount of carbon plant sends to their roots 3. Improving stress-resistance, allowing plants to grow on marginal land 4. Increasing crop and bioenergy yields With such improved efficiency, scientists anticipate the removal of several billion tons of additional carbon from the atmosphere annually, which may slow the accumulation of greenhouse gases and mitigate global warming. Source: http://www.eurekalert.org/pub_releases/2010-10/aiob-gat092810.php Plants have derived their energy from the sun for millions of years, so it’s about time we tap into the expertise of these vegetative powerhouses. According to a report released Friday, scientists are now exploring “artificial leaves” as an alternative to solar panels.
The leaf-like devices mimic photosynthesis—the process by which plants use sunlight to produce energy. They are comprised of a water-based gel (synthetic chlorophyll) that contains carbon-coated electrodes and light-sensitive molecules. Sunlight stimulates the molecules within the “leaves” to produce electricity, says Dr. Orlin Velev, the study’s lead researcher and a Professor of Chemical and Biomolecular Engineering at North Carolina State University. Scientists hope the bendable solar cells will someday provide a less expensive and more environmentally friendly alternative to the solid, silicon-based panels currently dominating the market. Veley envisions sheets of the bendable cells on the roofs of houses, but says such technology is not yet available. The artificial leaves are still impractical, but initial findings are promising. Veley’s research team hopes to improve upon the cells’ efficiency and regeneration capabilities. And perhaps someday the solar cells that power our houses will be as efficient as the houseplants we put in our windowsills. Source: http://news.ncsu.edu/releases/176mkvelevartificialleaves/ The “Great” that describes lakes Huron, Ontario, Michigan, Eerie and Superior obviously refers to their size, but with climate change, scientists fear it may be a less accurate descriptor of their water quality.
A team of 27 researchers from the University of Michigan and collaborating institutions received a $5 million grant this week from the National Science Foundation to find how climate change will affect the Great Lakes. Climate change research typically focuses on the amount and availability of water, but Anne Michalak, an associate professor at the University, will lead the investigation to determine its effects on water quality. Their approach is multidisciplinary, exploring the interplay of climate, hydrology, ecology, and social systems. The main focus is land use, which, on a regional scale, has a larger impact on the climate than greenhouse gases. Land use is affected by population, agriculture, and extreme weather events anticipated in conjunction with climate change. The Great Lakes basin is home to 10 percent of the U.S. population. Water here is essential to the region, providing drinking water, agricultural irrigation, and water-based recreation. The importance of these waters extends beyond the basin, though, comprising 84 percent of North America’s surface freshwater. Source: http://www.ns.umich.edu/htdocs/releases/story.php?id=7990 Feeding the tummies, gas tanks, and livestock of an ever-growing world population is coming at the expense of the world's tropical forests. This is the conclusion of a recent study by researchers at Stanford who found that 80 percent of new cropland developed between 1980 and 2000 in the tropics—half a million square miles—came from cutting down tropical forests.
Such deforestation sends carbon into the atmosphere, and lots of it. "The tropical forests store more than 340 billion tons of carbon, which is 40 times the total current worldwide annual fossil fuel emissions,” says Holly Gibbs, the study’s lead researcher. “If we continue cutting down these forests, there is a huge potential to further contribute to climate change." Researchers are encouraged that in recent years much of this land was cleared by corporate agribusiness rather than small, individual farmers. Agribusiness has been more responsive to the global market and consumer demands, reducing farmland expansion and instead boosting production on lands already in agricultural use. Crop yields have since increased, and the density of cattle grazing has been upped 5 or 6 fold in some areas. Such improved land use practices offer greater resource efficiency, said Gibbs, as well as hope for the future of sustainable farming. Source: http://www.eurekalert.org/pub_releases/2010-09/su-tfs090210.php |
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