COLUMBUS, Ohio - Are man-made wetlands really as good as the real thing? It's going to take scientists more than a dozen years to find out, according to a researcher at Ohio State University.

Ohio State's two experimental wetlands seem to be behaving quite differently -- one is 20 percent more productive than the other, but is far less diverse in terms of plant species. But both seem to contribute equally to reducing nitrates -- chemicals often found in pesticides.

"Right now, it seems to be a question of choosing between diversity vs. productivity when constructing a wetland," said William Mitsch, a professor of natural resources at Ohio State and the director of the Olentangy River Wetlands Research Park.

Mitsch presented six years of wetlands research Feb. 19 in Washington, D.C. at the annual meeting of the American Association for the Advancement of Science.

Six years ago, Mitsch and several volunteers planted about a dozen plant species in one two-and-a-half acre wetland, while letting nature develop the other equally sized wetland. "The unplanted wetland is now producing more biomass," he said. "It produces more peat, which translates to more vegetation, which means denser habitat for wildlife to conceal themselves." Also, more peat may impact the ability of the wetland to filter pollutants.

Three years into the experiment, the wetlands had converged -- they were nearly identical in terms of plant spe
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Contact: William Mitsch
Mitsch.1@osu.edu
614-292-9774
Ohio State University
5-Mar-2000