Biomassa aérea no semiárido da Paraíba, Brasil

Abstract

The goal of this study was to relate plant community structure, relief and altitude, soil texture and fertility and anthropogenic impact with aboveground live biomass(ALB), in order to determine which ecological factors are the major determinants of ALB in semiarid region of Brazil. We delimited 30 10 x 10 m plots in three conservation units in the State of Paraíba, where we sampled data of vegetation structure and soils. Releif and altitude were sampled from Google Earth. We compared the three areas in relation to vegetation structure and soil texture and fertility. We made linear regressions to detect which were the most important factors controling ALB. There is great amplitude in biomass, diametre, basal area, height and tree abundance among the conservation units, which indicates that most of the vegeation is in different successional stages throughout the sites, due to human interference. Therefore, most of the plots can, if let abandoned, reach a greater biomass. Also, tree height, crown cover and releif, together explained 61% of ALB variation. These results show that all areas are probably under constant human perturbation and this impact prevents other ecological factors to correlate with ALB.