BALTIMORE, Md. -- By analyzing how the northern U.S. Central Plains changed between grassland and forest due to past climate changes, Duke University ecologists have offered further evidence that the region will likely undergo drastic ecological changes due to 21st-century global warming.
In a report prepared for a meeting of the Ecological Society of America (ESA), the Duke scientists said the region responded readily to climate changes lasting decades or centuries during the mid-Holocene period -- 8,000 to 4,000 years ago -- by flip-flopping between grassland and forest. During this period, immediately after the last ice age, the region underwent many such short-term cycles of warming and cooling.
"We're finding that this system is really responsive, with the grasslands expanding eastward into forests and an increase in burning of this tallgrass prairie," said lead author James Clark, a professor of botany. Other co-authors of the paper were graduate students Eric Grimm and Jason Lynch.
In a variety of other Duke papers prepared for the meeting, Clark and his colleagues also reported more advances in understanding the ecological impact of global warming, including effects of climate change on carbon release from peatlands and on seed germination. This work was sponsored by the National Science Foundation and the Department of Energy.
Also at the meeting, the Duke ecologists reported other basic ecological studies that included methods to predict tree mortality, the effects of seed-eating predators on the production of seedlings and how seed dispersal affects biodiversity. This work was sponsored by the National Science Foundation.
In their studies of climate changes in the Central Plains, Clark and his
colleagues analyzed pollen and fire-produced charcoal laid down in sediments in
lakes in western Montana, the Dakotas, Nebraska, Minnesota and Wisconsin. Their
analyses revealed the plants that dominated t
Contact: Monte Basgall
Duke University Medical Center