Tag Archives: ecosystems

NASA’s HyspIRI Sees the Forest for the Trees and More

To Robert Green, light contains more than meets the eye: it contains fingerprints of materials that can be detected by sensors that capture the unique set of reflected wavelengths. Scientists have used the technique, called imaging spectroscopy, to learn about water on the moon, minerals on Mars and the composition of exoplanets. Green’s favorite place to apply the technique, however, is right here on the chemically rich Earth, which is just what he and colleagues achieved this spring during NASA’s Hyperspectral Infrared Imager (HyspIRI) airborne campaign.

“We have ideas about what makes up Earth’s ecosystems and how they function,” said Green, of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., who is principal investigator of the campaign’s Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) instrument. “But a comprehensive understanding requires us to directly measure these things and how they change over landscapes and from season to season.” (more…)

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Some Alaskan trout use flexible guts for the ultimate binge diet

Imagine having a daylong Thanksgiving feast every day for a month, then, only pauper’s rations the rest of the year.

University of Washington researchers have discovered Dolly Varden, a kind of trout, eating just that way in Alaska’s Chignik Lake watershed.

Organs such as the stomach and intestines in the Dolly Varden doubled to quadrupled in size when eggs from spawning sockeye salmon became available each August, the researchers found. They were like vacuums sucking up the eggs and nipping at the flesh of spawned-out salmon carcasses. (more…)

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Southwest Regional Warming Likely Cause of Pinyon Pine Cone Decline, Says CU Study

Creeping climate change in the Southwest appears to be having a negative effect on pinyon pine reproduction, a finding with implications for wildlife species sharing the same woodland ecosystems, says a University of Colorado Boulder-led study.

The new study showed that pinyon pine seed cone production declined by an average of about 40 percent at nine study sites in New Mexico and northwestern Oklahoma over the past four decades, said CU-Boulder doctoral student Miranda Redmond, who led the study. The biggest declines in pinyon pine seed cone reproduction were at the higher elevation research sites experiencing more dramatic warming relative to lower elevations, said Redmond of CU’s ecology and evolutionary biology department.  (more…)

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Emerging Consensus Shows Climate Change Already Having Major Effects on Ecosystems and Species

Plant and animal species are shifting their geographic ranges and the timing of their life events – such as flowering, laying eggs or migrating – at faster rates than researchers documented just a few years ago, according to a technical report on biodiversity and ecosystems used as scientific input for the 2013 Third National Climate Assessment.

The report, Impacts of Climate Change on Biodiversity, Ecosystems, and Ecosystem Services, synthesizes the scientific understanding of the way climate change is affecting ecosystems, ecosystem services and the diversity of species, as well as what strategies might be used by natural resource practitioners to decrease current and future risks. More than 60 federal, academic and other scientists, including the lead authors from the U.S. Geological Survey, the National Wildlife Federation and Arizona State University in Tempe, authored the assessment. (more…)

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USGS Study Tracks Pacific Walrus, Observes Effects of Arctic Sea Ice Loss on Behavior

ANCHORAGE, Alaska — Sparse summer sea ice in the Arctic over the past five years has caused behavioral changes in Pacific walruses according to research published by U.S. Geological Survey and Russian scientists. The effects on the walrus population are unknown.

“The loss of sea ice is the ‘why’ for the change in walrus behavior; the tracking data tells us the ‘where’ in terms of their new forage patterns,” said USGS Director Marcia McNutt. “What awaits to be seen is ‘how much will it matter?'” (more…)

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Not-So-Permanent Permafrost

MENLO PARK, Calif. — As much as 44 billion tons of nitrogen and 850 billion tons of carbon stored in arctic permafrost, or frozen ground, could be released into the environment as the region begins to thaw over the next century as a result of a warmer planet according to a new study led by the U.S. Geological Survey. This nitrogen and carbon are likely to impact ecosystems, the atmosphere, and water resources including rivers and lakes. For context, this is roughly the amount of carbon stored in the atmosphere today.

The release of carbon and nitrogen in permafrost could exacerbate the warming phenomenon and will impact water systems on land and offshore according to USGS scientists and their domestic and international collaborators. The previously unpublished nitrogen figure is useful for scientists who are making climate predictions with computer climate models, while the carbon estimate is consistent and gives more credence to other scientific studies with similar carbon estimates. (more…)

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Which Plants Will Survive Droughts, Climate Change?

New research by UCLA life scientists could lead to predictions of which plant species will escape extinction from climate change.

Droughts are worsening around the world, posing a great challenge to plants in all ecosystems, said Lawren Sack, a UCLA professor of ecology and evolutionary biology and senior author of the research. Scientists have debated for more than a century how to predict which species are most vulnerable.

Sack and two members of his laboratory have made a fundamental discovery that resolves this debate and allows for the prediction of how diverse plant species and vegetation types worldwide will tolerate drought, which is critical given the threats posed by climate change, he said. (more…)

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Evolving to Fight Epidemics: Weakness Can Be an Advantage

*Less resistance can sometimes be better than more–at least in a freshwater lake*

When battling a deadly parasite epidemic, less resistance can sometimes be better than more, a new study suggests.

A freshwater zooplankton species known as Daphnia dentifera endures periodic epidemics of a virulent yeast parasite that can infect more than 60 percent of the Daphnia population.

During these epidemics, the Daphnia population evolves quickly, balancing infection resistance and reproduction. (more…)

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