The Impact of Elevated Atmospheric [CO2] on Soil C and N Dynamics: A Meta-Analysis

Abstract

A review. Using meta-analytic techniques, the effect of elevated CO2concns. on soil carbon and nitrogen dynamics was investigated inseveral levels of ecosystem management. The anal. summarized theresults of 65 studies and covered data from both open-top chamber(OTC) and free-air CO2 enrichment (FACE) expts. Averaged over allstudies, soil C contents increased by 4.1%. A relatively strong increasein potential mineralizable Cand sol. C (+9.4%) suggests that therise in soil C is largely due to expanding labile C pools. The effectof CO2 enrichment on soil C contents depends on N availability; soilC contents only increased under elevated CO2 in expts. that received30 kg N per ha per yr or more. [on SciFinder(R)]