The impacts of land intensification on carbon (C) responses are important components of soil organic carbon (SOC) management. Grazing land intensification typically involves the use of highly productive plant species that can support greater grazing pressure, removal of higher proportions of site biomass and nutrients during mechanical harvest or grazing, and increased use of fertilizers, particularly N. Current improved grazing land management strategies are aimed at increasing above-ground biomass yield, with less regard for below-ground C dynamics. Since intensive management affects aboveand belowground C inputs (Schuman et al. 1999; Liu et al. 2011a, 2011b), it can have important implications for the amount and characteristics of SOC stored in grazing lands (Franzluebbers and Stuedemann 2003; Dubeux et al. 2006; Silveira et al. 2013). The objective of this study was to investigate the long-term impacts on SOC dynamics in subtropical ecosystems of converting native rangeland ecosystems into intensively managed systems.