The Relation Between Net Primary Productivity And Human Activities For Three Biomes In Bahia State, Brazil

Abstract

Brazilian biomes are hotspots of global biodiversity, important biomass producers and, consequently, help maintain the world’s carbon balance. Net primary production (NPP) is a variable used to determine carbon uptake by land cover. As environmental factors and human activities vary, net primary production increases or decreases. This study aimed to evaluate NPP in three Brazilian biomes – Atlantic Forest, Cerrado, and Caatinga – in the state of Bahia for the last 17 years, and to understand its relationship with human activities by analyzing burned areas, as well as interrelated environmental factors, such as climate variability and soil heat flux, using remote sensing. Using the MOD17 dataset, we find evidence that the Atlantic Forest biome is the one that absorbs more carbon in comparison to the Caatinga and Cerrado biomes, with a mean annual net primary production in each one of these three biomes equal to 1,227.89 g C m-2, 913.81 g C m-2, and 803.56 g C m-2, respectively. The years of El Niño influenced all biomes, and the results showed a strong relationship between climate and NPP in the studied biomes, especially in Caatinga, which is the most sensitive to climatic variations. Besides these results, we find evidence that, in all these biomes, the NPP dynamics have been affected by the increase in land use for agricultural and livestock activities, mainly because of deforestation and burning.