Soil microbial feedbacks to atmospheric CO2 enrichment

Increased atmospheric CO2 concentration often stimulates plant photosynthes is, enhances carbon (C) allocation belowground, increases plant nutrient up take and improves the efficiency of plant water use. Recent studies suggest that microbial responses to CO2-induced alterations in soil C, water and n utrient availability play an important role in determining ecosystem feedba ck to CO2 elevation. However, to date, most of the published results have b een obtained from short-term experiments or from studies using high-nutrien t or disturbed soils. Information on microbial responses to CO2-induced cha nges in natural and/or mature ecosystems with nutrient limitations is criti cal to predict changes in terrestrial ecosystem C storage under future CO2 scenarios.