Climate of Our Future

Invasion Of New Beach Grass Could Weaken Shoreline Protection

Science Daily — An invasion of American beach grass is under way along the Oregon coast, threatening to change dune ecology and reduce the ability of dunes to protect roads, property and towns from coastal storms.

A housing development behind a foredune created by European beach grass at Pacific City, Ore. (Credit: Image courtesy of Oregon State University)

Scientists at Oregon State University have documented a slow but steady takeover by this beach grass, an invasive species. They found that protective “foredunes” covered by the new grass species are only about half as high as those created by the European species of grass that were formerly dominant.

This phenomenon has already occurred from Long Beach, Wash., to Pacific City, Ore., and is continuing to spread, the researchers say. Keep reading

Amazon Forest Shows Unexpected Resiliency During Drought

Science Daily — Drought-stricken regions of the Amazon forest grew particularly vigorously during the 2005 drought, according to new research.

This image shows how the Amazon forest canopy’s ‘greenness’ differs from normal for the months of
July-September 2005 (drought peak). The greenness data is derived from NASA-EOS MODerate Imaging Spectroradiometer (MODIS) sensor aboard Terra Satellite. Green indicates above normal vegetation productivity compared to the 2000-2006 average, red indicates below normal, and yellow corresponds to normal . The study area is highlighted over a true color image background from NASA-EOS MODIS sensor for South America. (Credit: Kamel Didan, Terrestrial Biophysics and Remote Sensing Lab, The University of Arizona)

The counterintuitive finding contradicts a prominent global climate model that predicts the Amazon forest would begin to “brown down” after just a month of drought and eventually collapse as the drought progressed.

“Instead of ‘hunkering down’ during a drought as you might expect, the forest responded positively to drought, at least in the short term,” said study author Scott R. Saleska of The University of Arizona. “It’s a very interesting and surprising response.”

UA co-author Kamel Didan added, “The forest showed signs of being more productive. That’s the big news.” Keep reading