CO sub(2) Emission from Mineral Soils Following Land-Cover Change in Brazil

Carbon dioxide fluxes from soil in Brazil were calculated for the periods 1970 90 and 1975 95. The calculations were based on variations in soil C stocks as a function of land use, land-use changes, and forestry activities. All governing numerical equations are provided. The land-use system categories were defined according to the categories established by the Brazilian Institute of Geography and Statistics, which included the following: permanent culture, annual culture, resting land, natural pastures, planted pastures, natural forest, planted forest, productive lands not used, and inappropriate land. The resulting changes in CO sub(2) fluxes are tabulated for the different regions of the country. The calculations show that Brazilian soils are a net source of CO sub(2) to the atmosphere, but the emissions decreased from 93.9 Tg CO sub(2) for the period 1970 90 to 46.5 Tg CO sub(2) for the period 1975 95.