The DOE project involves intensive studies of 12 native plant species that currently exist with range limitations in the Pacific Northwest. Some are found no further south than southern Oregon, others no further north than Washington's Puget Sound. They serve as indicators of climate-change impacts on other native plant species, Bridgham said.
Such impacts also will be examined for the entire suite of native and exotic plants that occur in the research plots. Half of the plots at each site will be warmed above ambient conditions up to 5.4 degrees Fahrenheit using infrared lamps that emulate the physical mechanism of climate warming. Sprinklers will distribute 25 percent additional water above each year's annual rainfall in half of the plots to test combinations of warming and precipitation. The changes reflect projections for the next century; temperatures are expected to rise and rainfall is likely to increase in winters but give way to summer droughts.
"We will be looking at the effects of climate change on range distributions of plant species, particularly in upland prairies," said Bridgham, who will pursue the project with Johnson, a co-investigator on the grant. "These prairies were once widespread in this part of the Northwest but through a variety of reasons it is estimated that only about 2 percent still exist. They are imperiled ecosystems as are the species within them. On top of that we have climate change to deal with. This study is about biodiversity, and how these already stressed plant communities will handle climate change."
All sites are on lands managed by The Nature Conservancy, which holds many of the best remnants of native prairies in the region. Researchers will focus on the growth, reproduction and mortality of the plant species, factors which ultimately will control their range distributions under future climate change. Each of the three sites will contain 20 experimental circles.
|Contact: Jim Barlow|
University of Oregon