Elevated CO2 and litter decomposition in California annual grasslands: which mechanisms matter?

Dukes JS, Hungate BA. 2001. ECOSYSTEMS, in press.

To date, most research that has examined the effect of elevated atmospheric carbon dioxide concentration ([CO2]) on litter decomposition has focused on changes in the leaf litter quality of individual species. Results from California grasslands indicate that other CO2 responses may have greater consequences for decomposition rates. For instance, CO2-driven changes in either species dominance or patterns of biomass allocation would alter both the quality and the position of grassland litter. Here, we review results from studies in California grasslands to identify mechanisms that will affect grassland litter decomposition. We use a simple calculation that integrates the results of two studies to identify three mechanisms that have the potential to substantially alter decomposition rates as the atmospheric [CO2] rises.