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…
Populations of marine fish may lose genetic diversity even if fishing stops while there are still several million individuals – a number previously assumed to be enough to preserve a diverse gene pool.
Losing the diversity of key genes can render a population less productive and unable to adapt when faced with challenges such as global warming, pollution or changes in predators or prey. Rare genetic variation of little importance today might be the key to adaptability in the future, accordin
Generating rainfall for deserts using wind power and seawater is the subject of a new research project.
The idea involves the installation at sea of specially designed wind turbines. The turning motion of the rotors would be harnessed to pump seawater along the turbines’ hollow blades. The water would then be forced out through slits as a fine spray. These drops would evaporate, with salt falling back into the sea and a cloud of water vapour drifting inland, increasing the probabilit
In an effort to stabilize climate and slow down global warming, Livermore scientists along with a team of international researchers have evaluated a series of new primary energy sources that either do not emit or limit the amount of carbon dioxide released to the atmosphere.
Possible candidates for primary energy sources include terrestrial, solar and wind energy; and solar-power satellites; biomass; nuclear fission; nuclear fusion; fission-fusion hybrids and fossil fuels from which carbon h
Models of Larch budmoth outbreaks in the European Alps may eventually show scientists how to model a variety of disease and insect eruptions that rely on a combination of enemy, host and spatial movement to decimate populations, according to a team of ecologists.
“We use theoretical models to help understand the spatial component in these outbreaks and to predict how spatial spread occurs,” says Dr. Ottar N. Bjornstad, assistant professor of entomology and biology at Penn State. “With local
As detected by ESA satellite sensors, the recent eruptions of the Mount Etna volcano in Sicily are throwing huge amounts of ash and trace gases into the atmosphere. Working with data from the Global Ozone Monitoring Experiment (GOME) sensor onboard ESA’s ERS-2 spacecraft, scientists at the German aerospace centre (DLR) report that levels of sulphur dioxide from the eruptions on Sunday and Monday are at least 20 times higher than normal.
As detected by ESA satellite sensors, the recent erupt
The rapid increase of nitrogen falling from the sky as a result of fossil-fuel combustion and crop fertilization, combined with carbon stored in Earths soils, could change the rate of the greenhouse gas, carbon dioxide, rising into the atmosphere, according to a new study.
Scientists believe about 300 times more carbon is stored in soils than is being put in the atmosphere in the form of C02, according to biology Assistant Professor Alan Townsend of the University of Colorado at Bould
Genetically modified Bt crops are now widely used in the USA.
These crops contain genes from bacteria that make them toxic to some insect pests. A central concern in regulating these genetically modified crops is the risk of insects evolving resistance to the Bt toxins.
To reduce this risk, the “high dose/refuge” strategy is now being used, in which non-Bt fields (refuges for insect pests) are planted near Bt fields (where there is high dose of toxin).
In the Nove
Texas research shows mid-September success with containerized trees
Most foresters hold to the straight and narrow when it comes to planting pine trees: nursery seedlings go in the ground between Dec. 1 and March 1. Period.
But a Texas Agricultural Experiment Station study is branching out to show that early planting — even as early as mid-September – can give slash pine trees a growing head start towards better survivability, thus faster regrowth on harvested or burnt area
An increased frequency of extreme precipitation events has been observed over the last 100 years in the United States. Global climate models project that similar trends may continue and even strengthen over the coming decades, due to climate change. Now, a study using computer climate and crop model simulations predicts that U.S. agricultural production losses due to excess rainfall may double in the next 30 years, resulting in an estimated $3 billion per year in damages.
Cynthia Rosenzweig
A recent study of coral formations in different tropical locations will be used to help geologists reconstruct climate and storm patterns of the past and learn more about the preservation of reefs. The findings will be presented by David Meyer, University of Cincinnati professor of geology, at the upcoming 2002 meeting and exposition of the Geological Society of America.
Meyer’s previous research established that coral reefs can be an index of the ocean’s health and are greatly impacted by
Two of the three largest impact craters on Earth have nearly the same size and structure, researchers say, but one was caused by a comet while the other was caused by an asteroid. These surprising results could have implications for where scientists might look for evidence of primitive life on Mars.
Susan Kieffer of the University of Illinois at Urbana-Champaign, Kevin Pope of Geo Eco Arc Research and Doreen Ames of Natural Resources Canada analyzed the structure and stratigraphy of the 65 m
Antibiotics have been used against infectious diseases with great success and have been a part of agriculture for many years. Agricultural uses of antibiotics include the treatment and prevention of diseases in animals and plants and the promotion of growth in food animals. But scientists have long recognized a down side. The concentrated and widespread use of antibiotic agents has resulted in the emergence of drug-resistant organisms, some of which can now survive most commercially available antibio
About 150,000 years ago, an anomalous ice age was triggered by an increasingly salty Mediterranean Sea, a development thats occurring today and may start new ice sheet growth in the next few decades, according to a study at the University of Minnesota. Robert Johnson, an adjunct professor of geology and geophysics, will present his study of the glaciation 150,000 years ago and discuss its implications for todays climate on Tuesday, Oct. 29, at the annual meeting of the Geological Society
Geological sciences researchers at Virginia Tech are using GPS antennas to measure aquifer use and storage capacity. At the Geological Society of Americas 114th annual meeting in Denver, Oct. 27-30, masters degree student Sandra Warner will make the case for the broader coverage of such tools.
Warner and Virginia Tech geological sciences professor Thomas Burbey are conducting a large-scale aquifer test on a new municipal well in the Virgin River Valley near Mesquite, Nev. In add
Atmospheric particles that become acidic through exposure to such pollutants as sulfuric acid can lead to vast increases in the formation of secondary organic aerosols, a new study indicates. Such aerosols are major components of the unsightly haze that hangs over cities and oil refineries and even affects otherwise pristine U.S. national parks.
A report on the research appears in Fridays (Oct. 25) issue of the journal Science. Authors, all at the University of North Carolina at Chapel
Robotic Carbon Explorers test the “iron hypothesis” in nature
In the spring of 2001, two robotic Carbon Explorer floats recorded the rapid growth of phytoplankton in the upper layers of the North Pacific Ocean after a passing storm had deposited iron-rich dust from the Gobi Desert. The carbon measurements, reported in the October 25 issue of Science, are the first direct observation of wind-blown terrestrial dust fertilizing the growth of aquatic plant life.
A group of scie