Effect of Caatinga forest management on organic carbon stock in soil aggregates

One of the main alternatives for the rational exploitation of the Caatinga biome's natural resources is sustainable forest management (FM) which can influence different components of the ecosystem, such as vegetation and soil. Therefore, the objective of this study was to evaluate the short-term effect of different forest management practices on total organic C stocks and soil aggregate classes in the Caatinga area located in Contendas do Sincora (BA). Three forest management practices (selectively cutting by species, selectively cutting by diameter and clear cutting) were evaluated, using the unmanaged Caatinga as a control. Soil samples were collected at 0-10 cm depth after two years of natural regeneration, following the management treatments. Soil samples were fractionated to obtain macroaggregated fractions (2000-250 mu m), microaggregates (250-53 mu m) and silt+clay (<53 mu m). The first two fractions were sonicated to obtain the occluded and particulate carbon. In the short-term, forest management promoted reduction of total organic C stocks, but did not cause changes in the distribution and C stocks of the aggregate classes.