Effects of elevated atmospheric CO2 on soil organic carbon dynamics in a mediterranean forest ecosystem

摘要: Elevated atmospheric CO 2 has the potential to change composition and dynamics of soil organic matter (SOM) consequently C N cycling in terrestrial ecosystems. Because long-lived nature SOM, long-lasting experiments are required for studying effect elevated on dynamics. Therefore, study ecosystems that have been exposed long-term enhanced concentrations is highly desirable better understanding feedback mechanisms between litter production, quality, decomposability level.This work deals with chemical mineralization a leaf litter-soil continuum around mineral spring Mediterranean woodland ecosystem. Leaf from Quercus cerris L., pubescens Willd. Smilax aspera samples forest floor (F HA layers) 0-10 cm were taken at ambient concentrations, analyzed (C, N, lignin, cellulose, polyphenols). plant determined using litterbag laboratory incubation methods.Elevated affected neither nor elemental ratios litter. The rate during decomposition was not by , accordance absence quality . produced high had higher initial stage period. This difference, however, disappeared end incubation. Q. than subsequently vitro faster rates, but under field conditions did differ significantly two species.Total contents so soil. For three layers, total C/N Total pool sizes doubled such effects seen rates layers areas those conditions. Although immobilization F plots lower, A horizon .The increase carbon an can be explained increased biomass production Under pools also increased, lower casts some doubt common view changes plants, thereby slows down release. species strong influence cycles increasing may more important feedbacks concentration given species.