Environment

One of the challenges of managing forests is deciding among management practices, particularly when the landscape effects these practices will have are not fully known. Since 1995, Pacific Northwest (PNW) Research Station scientists and their colleagues from Oregon State University and the Oregon Department of Forestry have been conducting research that provides managers with a better idea of the effects—both intended and unintended—that forest management practices can have on landscapes. "This research is one of the first and most integrated studies of the ‘big picture’ of forest…

Climate change could trigger "boom and bust" population cycles that make animal species more vulnerable to extinction, according to Christopher C. Wilmers, an assistant professor of environmental studies at the University of California, Santa Cruz. Favorable environmental conditions that produce abundant supplies of food and stimulate population booms appear to set the stage for population crashes that occur when several "good years" in a row are followed by a bad year. "It's almost paradoxical, because you'd think a large population would be better off, but it turns out they're more…

Polychlorinated diphenyl ethers (PBDEs), common in flame retardants, have shown steady increases in the environment. These compounds accumulate through the food chain, reaching high levels in top predators. A new study published in the latest issue of Environmental Toxicology and Chemistry provides the first evidence of the harmful effects of these contaminants to a mammalian top predator, the mink. Because PBDEs are similar to substances such as polychlorinated biphenyls (PCBs) that have been shown to be harmful to top predators, concern has been increasing regarding possible harmful…

The 11,000 members of three scientific societies with its roots in agriculture have been closely watching the reports coming out of the Intergovernmental Panel on Climate Change (IPCC). It is the IPCC’s 4th Assessment Report released on April 6, "Climate Change 2007: The Physical Science Basis" that points to the direct consequences of climate change. Leading scientists from all over the world contributed to the latest installment of this report that attributes ecosystem changes to human-induced global warming. Following the release of the report, the presidents of the American Society of…

Planting and protecting trees—which trap and absorb carbon dioxide as they grow—can help to remove carbon dioxide from the atmosphere. But a new study suggests that, as a way to fight global warming, the effectiveness of this strategy depends heavily on where these trees are planted. In particular, tropical forests are very efficient at keeping the Earth at a happy, healthy temperature. The researchers, including Ken Caldeira of Carnegie’s Department of Global Ecology and Govindasamy Bala at Lawrence Livermore National Laboratory, found that because tropical forests store large amounts of…

The nonnative invasive grass Microstegium vimineum may hinder the regeneration of woody species in southern forests. Chris and Sonja Oswalt (Forest Service Southern Research Station) and Wayne Clatterbuck (University of Tennessee) set up experiments on a mixed-hardwood forest in southwest Tennessee to study the growth of the invasive grass under different levels of forest disturbance. Study results were published online in the journal Forest Ecology and Management on March 27, 2007. M. vimineum, commonly called Nepalese browntop or Japangrass, was first identified in 1919 near Knoxville,…

A new study coordinated by the New York-based Wildlife Conservation Society and other groups found that Central Africa’s increasing network of roads – which are penetrating deeper and deeper into the wildest areas of the Congo Basin – are becoming highways of death for the little known forest elephant. The study, which appears in the journal Public Library of Science, concludes that forest elephants are severely impacted by ivory poachers who use roads to gain access into their remote jungle home. In addition, roads serve as conduits of advancing human settlement fragmenting previously…

It is a natural history tale that every third grader knows: The dinosaurs ruled the Earth for hundreds of millions of years, until an asteroid struck the Yucatan Peninsula and triggered a mass extinction that allowed the ancestors of today’s mammals to thrive. The asteroid part of the story may still hold true, but a new study challenges the notion that a mass extinction of dinosaurs 65 million years ago played a major role in the dominance of today’s mammals. An international team of scientists including University of Georgia Institute of Ecology Director John Gittleman has constructed a…

The success of science based management in Alaska is emphasized in a newly released report. “Conserving Alaska’s Oceans,” was prepared by Natural Resources Consultants, a research organization based in Seattle, Washington and released by the Marine Conservation Alliance. The report outlines 30 years of improved ocean conservation in the waters off Alaska with recommendations for future action. The “Alaska Model” has been cited as a leading example of science-based management. In Alaska catch limits do not exceed the harvests recommended by science advisers, and there are no overfished stocks…

Over a span of two decades, warming temperatures have caused annual losses of roughly $5 billion for major food crops, according to a new study by researchers at the Carnegie Institution and Lawrence Livermore National Laboratory. From 1981-2002, warming reduced the combined production of wheat, corn, and barley—cereal grains that form the foundation of much of the world’s diet—by 40 million metric tons per year. The study, which will be published March 16 in the online journal Environmental Research Letters, demonstrates that this decline is due to human-caused increases in global…