Soil Carbon Dynamics in Native Ecosystems and Reforestation in Santa Catarina

ABSTRACT Changes in land use combined with management practices contribute to changes in soil carbon inputs and outputs. This study aimed to evaluate the soil carbon dynamics in native ecosystems and reforestation in Santa Catarina. The study was conducted between February and May, 2007. The following areas were evaluated: Native Field (NF); Araucaria Forest (AF); Eucalyptus (ER) and Pinus (PR) reforestation. Carbon stocks, carbon microbial biomass (CMB), soil basal respiration (SBR), microbial (qMic) and metabolic (qCO2) quotients were analyzed. The highest concentrations of carbon were found in AF and NF, and biochemical characteristics indicated that NF and AR have the best capacity to store carbon in soil among the land use systems evaluated. Eucalyptus and Pinus reforestation showed high rates of SBR, qCO2 and low concentrations of CMB that suggest these land use systems lose more CO2 to atmosphere than native ecosystems.