Tag Archives: ecosystems

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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Mesquite Trees Displacing Southwestern Grasslands

Mesquite trees and woody shrubs are better adapted than grasslands to a Southwestern climate predicted to shift toward higher temperatures and greater variability in rainfall, UA ecologists have discovered.

As the desert Southwest becomes hotter and drier, semi-arid grasslands are slowly being replaced by a landscape dominated by mesquite trees, such as Prosopis velutina, and other woody shrubs, a team of University of Arizona researchers has found.

In a “leaf-to-landscape” approach, the team combined physiological experiments on individual plants and measurements across entire ecosystems to quantify how well grasslands, compared to mesquite trees and woody shrubs, cope with heat and water stress across seasonal precipitation periods. (more…)

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New Projection Shows Global Food Demand Doubling by 2050

*Increasing yield in poorer countries could decrease adverse environmental effects*

Global food demand could double by 2050, according to a new projection reported this week in the journal Proceedings of the National Academy of Sciences (PNAS).

The analysis also shows that the world faces major environmental challenges unless agricultural practices change.

Scientists David Tilman and Jason Hill of the University of Minnesota (UMN) and colleagues found that producing the amount of food needed could significantly increase levels of carbon dioxide and nitrogen in the environment, and may cause the extinction of numerous species. (more…)

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NSF Announces Major Awards for Biodiversity Research, WHOI Scientists Selected

The 1977 discovery of deep-sea hydrothermal vent ecosystems that obtain energy through chemosynthesis rather than photosynthesis greatly expanded the perception of life on Earth. However, an understanding of their underlying microbiology and biogeochemistry still remains elusive.

A newly funded project, one of several major awards announced by the National Science Foundation’s (NSF) Dimensions in Biodiversity research program, stands to change that through a multi-disciplinary, international collaborative research effort led by Associate Scientist Stefan Sievert of the Woods Hole Oceanographic Institution. (more…)

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Fossil Bird Study Describes Ripple Effect of Extinction in Animal Kingdom

GAINESVILLE, Fla. — A University of Florida study demonstrates extinction’s ripple effect through the animal kingdom, including how the demise of large mammals 20,000 years ago led to the disappearance of one species of cowbird.

The study shows the trickle-down effect the loss of large mammals has on other species, and researchers say it is a lesson from the past that should be remembered when making conservation, game and land-use decisions today. (more…)

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