UPTON, NY -- Biodiversity is an important factor regulating how ecosystems will respond to increasing atmospheric carbon dioxide, say researchers from the U.S. Department of Energys Brookhaven National Laboratory and their collaborators from several universities. The team of investigators, led by Peter Reich of the University of Minnesota, just released results from a major field study that will appear in the April 12, 2001 issue of Nature. The scientists found that more diverse plant ecosystems were better able to absorb carbon dioxide (CO2) and nitrogen (N), both of which are on the rise due to human activities and industrial processes.
"The key implication of this research is that, in response to elevated levels of CO2 and N, ecosystems with high biodiversity will take up and sequester more carbon and nitrogen than do ecosystems with reduced biodiversity," says Brookhaven plant physiologist David Ellsworth, one of the study authors.
The experiment, called BioCON (Biodiversity, CO2 and N), is the first field study to test the hypothesis that plant species diversity influences ecosystem-scale responses to elevated CO2 and N levels. It was performed in a scientifically controlled grassland environment at the Cedar Creek Natural History area of the University of Minnesota, using free-air CO2 enrichment, or FACE, technology. This experimental technology was developed by Brookhaven National Laboratory to study the effects of enhanced CO2 on plants in their natural environment, rather than in greenhouses or other enclosures.
Each FACE facility consists of six 20-meter diameter experimental plots, each encircled by a ring of five-foot tall vertical pipes capable of releasing varying concentrations of CO2. Computers monitor the wind speed, wind direction, and CO2 level within each ring, and adjust the release of CO2 to achieve an atmospheric concentration at a level that is expected to occur fifty years from now.