Earth

Climate change enhances grassland productivity

Bayreuth/Leipzig. More frequent freeze-thaw cycles in winter can increase biomass production according to the results of a recent study conducted by the Helmholtz Center for Environmental Research (UFZ), the University of Bayreuth and the Helmholtz Center in Munich. For their experiment at the Ecological-Botanical Garden of the University of Bayreuth the researchers installed underground heating on their plots, thereby enabling five additional thawing periods to take place in the winter of 2005/2006.

Dramatic expansion of dead zones in the oceans

Unchecked global warming would leave ocean dwellers gasping for breath. Dead zones are low-oxygen areas in the ocean where higher life forms such as fish, crabs and clams are not able to live. In shallow coastal regions, these zones can be caused by runoff of excess fertilizers from farming. A team of Danish researchers have now shown that unchecked global warming would lead to a dramatic expansion of low-oxygen areas zones in the global ocean by a factor of 10 or more.

Scientists use lasers to measure changes to tropical forests

HILO, Hawaii January 23, 2009—New technology deployed on airplanes is helping scientists quantify landscape-scale changes occurring to Big Island tropical forests from non-native plants and other environmental factors that affect carbon sequestration.

U.S. Forest Service and Carnegie Institution scientists involved in the research published their findings this month in the journal Ecosystems and hope it will help other researchers racing to assess threats to tropical forests around the world.

NAU research ties tree mortality trends to climate warming

(Flagstaff, Ariz.- Jan. 23, 2009) - Global warming is speeding up the mortality of trees, and Northern Arizona University research is providing some of the data to prove it.

Pete Fulé, an NAU associate professor in the School of Forestry and a director of the university's Ecological Restoration Institute, is a coauthor of "Widespread Increase of Tree Mortality Rates in the Western United States," an article to be published in the Jan. 23 issue of Science journal.

Danube delta holds answers to 'Noah's flood' debate

Did a catastrophic flood of biblical proportions drown the shores of the Black Sea 9,500 years ago, wiping out early Neolithic settlements around its perimeter? A geologist with the Woods Hole Oceanographic Institution (WHOI) and two Romanian colleagues report in the January issue of Quaternary Science Reviews that, if the flood occurred at all, it was much smaller than previously proposed by other researchers.

Tree death rate in Pacific Northwest doubled in 17 years

Trees are dying twice as fast as they did three decades ago in older forests of the western United States and scientists suspect warming temperatures are a contributing factor.

Warmer climate causing huge increase in tree mortality across the West

CORVALLIS, Ore. – Regional warming and drought stress are the "dominant contributors" to a rapid increase of tree mortality in old growth forests across the West during the past 50 years, a new report concludes, with the Pacific Northwest the hardest hit of all areas studied.

The findings, to be published Friday in the journal Science, suggest that a persistent increase in the mortality rate would ultimately cause a 50 percent reduction in the average tree age in forests, a potential reduction in average tree size and make many forests vulnerable to abrupt dieback.

Tree deaths have doubled across the western US

Tree death rates have more than doubled over the last few decades in old-growth forests of the western United States, and the most probable cause of the worrisome trend is regional warming, according to a U.S. Geological Survey-led (USGS) study published in Science on January 23.

The study found that the increase in dying trees has been pervasive. Tree death rates have increased across a wide variety of forest types, at all elevations, in trees of all sizes, and in pines, firs, hemlocks, and other kinds of trees.

New study links western tree mortality to warming temperatures, water stress

A new study led by the U.S. Geological Survey and involving the University of Colorado at Boulder indicates tree deaths in the West's old-growth forests have more than doubled in recent decades, likely from regional warming and related drought conditions.

Scientists find new way to produce hydrogen

Scientists at Penn State University and the Virginia Commonwealth University have discovered a way to produce hydrogen by exposing selected clusters of aluminum atoms to water. The findings are important because they demonstrate that it is the geometries of these aluminum clusters, rather than solely their electronic properties, that govern the proximity of the clusters' exposed active sites. The proximity of the clusters' exposed sites plays an important role in affecting the clusters' reactions with water.

Satellites confirm half-century of West Antarctic warming

The Antarctic Peninsula juts into the Southern Ocean, reaching farther north than any other part of the continent. The southernmost reach of global warming was believed to be limited to this narrow strip of land, while the rest of the continent was presumed to be cooling or stable.

Not so, according to a new analysis involving NASA data. In fact, the study has confirmed a trend suspected by some climate scientists.

Invasions by alien plants have been mapped in European Union

Biological invasions are one of the major threats to biodiversity and in many cases they have considerable impact on economy and human health. For their effective management it is important to understand which areas and ecosystems are at the highest risk of being invaded.

The first map of the level of alien plant invasions in European Union was published in the Wiley-Blackwell journal Diversity and Distributions.

Off the shelf maps help mitigate volcanic hazards

When volcanoes erupt, pinpointing the regions at high risk for lethal hazards and deciding whether or not to evacuate a resistant population comprise the most difficult problems faced by hazards managers. Now a team of volcanologists has a program that maps potential problem areas quickly, taking much of the guesswork out of decision making and evacuations.

Earth's seasons now arrive 2 days earlier, UC Berkeley, Harvard researchers report

Berkeley -- Not only has the average global temperature increased in the past 50 years, but the hottest day of the year has shifted nearly two days earlier, according to a new study by scientists from the University of California, Berkeley, and Harvard University.

Just as human-generated greenhouse gases appear to the be the cause of global warming, human activity may also be the cause of the shift in the cycle of seasons, according to Alexander R. Stine, a graduate student in UC Berkeley's Department of Earth and Planetary Science and first author of the report.

Researchers cooking up new gelled rocket fuels

WEST LAFAYETTE, Ind. - Engineers and food scientists are teaming up to develop a new type of gelled fuel the consistency of orange marmalade designed to improve the safety, performance and range of rockets for space and military applications.

"This is a very multidisciplinary project," said Stephen Heister, the Purdue University professor of aeronautics and astronautics who is leading one of two teams on the project, which is funded by the U.S. Army Research Office.