New study finds that the nutritional value of prey within a single species can widely vary, offering key insights for food web dynamics and ecosystem change The hunt is on and a predator finally zeroes in on its prey. The animal consumes the nutritious meal and moves on to forage for its next target. But how much prey does a predator need to consume? Following a period of massive starvation among animals living along the California coast, University of California…
Orbit affects climate on Mars similar to the way it affects climate on Earth, say three scientists, who used a model of climate change on Earth to explain the layers of deposits in the polar regions of the Red Planet.
Their study appears in the Sept. 26 issue of Nature, and suggests that a climate change theory for Earth can also be applied to Mars and possibly to other Earth-like planets.
“The orbital theory of climate change has been successful in explaining changes in the Earth&
Habitat fragmentation is a primary threat to amphibians worldwide, and new research suggests one of the reasons why. Experimental evidence for three species shows that fragmentation may hinder the dispersal of juvenile amphibians, which could contribute to population declines.
“Habitat fragmentation is likely to reduce dispersal rates between local populations of these three species,” say Betsie Rothermel and Raymond Semlitsch of the University of Missouri in Columbia in the October issue o
Based on satellite data from the European Space Agency, the national meteorological centre of the Netherlands predicts the Antarctic ozone hole will break apart this week, months earlier than usual.
A scientist at the Royal Netherlands Meteorological Institute (KNMI) adds that the depth of the ozone hole is much smaller than previously seen.
“This breakdown is occurring exceptionally early in the year, about two months earlier than normal”, says Henk Eskes, a KNMI senior scientist.
Sudden collapses in many ecological systems are the rule rather than exceptions to the rule. This is shown by Professor Lennart Persson of Umeå University, Sweden, in the latest issue of the scientific journal Proceedings of the National Academy of Sciences. Among other things, the article provides an explanation for the collapses in cod stocks in different parts of the world. Several models have shown that ecological systems can experience catastrophic collapses. On the other hand, th
Active mountain ranges like the Olympic Mountains, Taiwan Central Range or the Southern Alps are still growing, but they are not getting any taller. River cutting and erosion keep the heights and widths of uplifted mountain ranges in a steady state according to an international team of geoscientists.
“These mountains grew to 2.5 to 3 miles high over the past few million years and then they stopped increasing,” says Dr. Rudy L. Slingerland, professor of geology and head of Penn States g
A new study using a computer climate model to simulate the last 50 years of climate changes, projects warming over the next 50 years regardless of whether or not nations curb their greenhouse gas emissions soon. If no emission reductions are made and they continue to increase at the current rate, global temperatures may increase by 1-2 degrees Celsius [2-4 degrees Fahrenheit]. But if the growth rate of carbon dioxide does not exceed its current rate and if the growth of true air pollutants (substance
Winter temperatures are on the rise and scientists note this change will actually increase a plant’s exposure to freezing temperatures
Scientists from Agriculture and Agri-Food Canada predict crops will be at a greater risk of winter damage in the future even though the climate will be warmer. Perennial forage crops are grown on more than 40% of the cultivated land in Eastern Canada and other regions of North America, where they constitute the backbone of the livestock industry. The
A new study by Stanford University geophysicists is raising serious questions about a fundamental technique used to make long-range earthquake predictions.
Writing in the journal Nature, geophysicists Jessica Murray and Paul Segall show how a widely used earthquake model failed to predict when a long-anticipated magnitude 6 quake would strike the San Andreas Fault in Central California.
In their Sept. 19 Nature study, Murray and Segall analyzed the “time-predictable recurrence mod
California scientists credit synthetic aperture radar imagery from the European Space Agency with making possible new ways to depict earthquake fault zones and uncovering unusual earthquake-related deformations. Their study of imagery from a 1999 earthquake in the western US could provide a new way to identify active faults and help track when the last earthquake occurred on a fault zone.
Writing in last week’s issue of Science magazine, researchers from the Scripps Institution of Oceanograp
Frustrated by the limitations of present numerical models that simulate how Earths climate will be altered by factors such as pollution and landscape modification, Duke University engineers are creating a new model incorporating previously-missing regional and local processes.
“The model we are developing is much more refined,” said the projects leader, Roni Avissar, chairman of the Department of Civil and Environmental Engineering at Dukes Pratt School of Engineering.
Driven by precise new satellite measurements and sophisticated new computer models, a team of NASA researchers is now routinely producing the first global maps of fine aerosols that distinguish plumes of human-produced particulate pollution from natural aerosols.
In the current issue of the journal Nature, atmospheric scientists Yoram Kaufman, at NASAs Goddard Space Flight Center, Greenbelt, Md., Didier Tanré and Olivier Boucher from CNRS (Centre National de la Recherche Scientifique)
Project Synopsis:
The PEOPLE project involves the monitoring of ambient outdoor and indoor levels of air pollutants as well as measuring population exposure in European capitals. With the selection of benzene as a first pollutant to be measured, EC directive 2000/69/EC is also supported. Benzene is a carcinogenic pollutant to which exposure is associated with the risk of the development of leukaemia.
Brussels and Lisbon have been selected as the first cities for the PEOPLE
Scientists at the University of Sheffield have used fossilised leaves to determine the effect of greenhouse gases on the end of the Ice Age 300m years ago, according to an article published in PNAS.
The study, led by Professor David Beerling, examined fossilised leaves to determine how much carbon dioxide was in the air at various periods during the ice age.
Leaves have pores on their surface called stomata that act as “air holes” and open and close depending on the levels of carbo
To combat urban sprawl and protect wildlife, many communities have set aside land for wildlife corridors linking natural areas to one another.
Public support for these greenways, however, has overshadowed a long-running debate among ecologists about whether they actually achieve their presumed benefits. The debate has been hobbled by a lack of definitive data, with many studies based solely on observations and others only on small-scale experiments, scientists say.
A University of
Scientists may soon have a better idea of the potential effects of global warming thanks to the work of Tony O’Hagan, Professor of Statistics at the University of Sheffield.
Scientists already know that global warming will have consequences for the earth but are unsure how mild or severe these effects may be, due to the inaccuracies in their prediction models. Professor O’Hagan’s method will allow scientists to better determine these inaccuracies and has major significance in the world of
Analysis uncovers unusual earthquake-related deformation, paves the way for methods to identify new active faults
On Oct. 16, 1999, approximately 37 miles from Palm Springs, Calif., a magnitude 7.1 earthquake ripped through 28 miles of faults in the Mojave Desert. Because of the area’s sparse population and development, the massive quake caused virtually no major measurable injuries or destruction.
Yet the “Hector Mine” event, named after a long-abandoned mine in the area, ha