ASSESSMENT OF SOIL CARBON STOCK CHANGES AGAINST LAND USE AND LAND COVER CHANGES IN RIO DE JANEIRO STATE, BRAZIL

In recent decades, environmental issues involving global warming and land use changes have been widely discussed. Carbon is a key element in this context, and its cycle in nature is interconnected with various ecosystem functions. This study uses soil organic carbon (SOC) stock and land use/land cover (LULC) maps from the MapBiomas project to evaluate SOC stock changes against LULC changes in the state of Rio de Janeiro, Brazil, between the years 1985 and 2021. The results suggest a relative stability in SOC stocks, despite local stock changes ranging from -196 to 226 Mg ha^-1. Major SOC increases can be observed in pastures and moderate increases in forests, while high decreases are associated with urban areas and close to fragile environments with high biodiversity, such as restinga and mangrove ecosystems. Attention should be given, however, to the limitations posed by the uncertainties of the SOC stock and LULC input maps.