We investigate the effects of climate change on ecosystems and the resulting feedback effects on climate. Overhead electric heaters are used to warm Rocky Mountain meadow plots by the amount expected from global warming next century. Effects of climate change on soil microclimate, carbon and nitrogen cycling, plant growth and flowering time, and species diversity are monitored. Heating has increased the length of the growing season, altered the timing of flowering, increased the rate of nitrogen cycling, caused sagebrush to expand at the expense of other plants, and caused a 20% decrease in soil carbon. To extend our knowledge of such effects, we are also investigating ecological trends in meadow plots that lie along a natural elevational and climate gradient. The combined knowledge from heated plots and from the natural climate gradient is providing a unified picture of ecosystem-climate interactions across a wide range of space and time scales.
