Landscape level data on soil organic carbon (SOC) mineralization is uncommon; yet they are needed in order to spatially understand carbon mineralization and to upscale to the landscape level and to assess the effect of historic land use changes. The aerobic SOC mineralization rates in 141 soils representing nine land uses in a North Florida watershed were determined using an innovative CO₂ analysis method. Mineralized SOC was linear with time (overall average r² = 0.98 ± 0.04). Constant rates of mineralization were maintained during the 87 days of incubation. SOC mineralization rates ranged from 1.3 to 74.0 µg C g^-1 soil d^-1. Mineralization rates, when ranked by land use were: wetland >> rangeland > urban > improved pasture > upland forest, crop, forest regeneration > pine plantation. Although wetland soil produced the greatest amount of mineralizable C, it also showed the lowest specific SOC mineralization rate, 4.2 mg C g^-1 C d^-1 ± 1.3, which was significantly lower than the other land uses (p<0.005). The specific SOC mineralization rate ranged from 1.8 to 20.4 mg C g^-1 C d^-1 with land uses ranked: urban, upland forest, crop, range land > improved pasture > pine plantation > forest regeneration. The mineralization rate (µg C g^-1soil d^-1) for all soils was directly related to total soil carbon content, hot water extractable carbon, and recalcitrant carbon (r²=0.62, 0.63, and 0.60, respectively). This relationship was strongest for wetland soils (r² = 0.88, 0.89 and 0.86, respectively), and poor for improved pasture soils (r² < 0.33). Other variables such as soil type, drainage class and soil pH, were not related to SOC mineralization.  Hydrolyzable C content was not significantly related to the SOC mineralization rate.  Comprehensive mineralization data for a watershed, as collected in this study, provide a framework for developing landscape-scale models to assess mineralizable soil C pools and changes associated with historic and future land use changes.