Influence of Soil Type and Rocky Outcrops on the Species Distribution in a Woody Plant Community at Brazilian Semiarid

Cerrado is a biome that holds many phytophysiognomies, influenced by the edaphic factors, where the type of substrate is strongly related to the established vegetation. This study aims to verify on how soil physicochemical properties, as well as the presence of rocky outcrops, influence the species distribution of woody plants in a Cerrado fragment located in deep soils and tabular relief at Serra do Boqueirão (289 m elev.) Lavras da Mangabeira municipality (6º72′24″ S; 38º97′73″ W), Northeastern Brazil. Every individual with a DNS ≥ 3 cm in 12 sampling units with an area of 12 × 30 m (0.432 ha) was sampled. PAST v. 3.23 software was used in the Main Component analyses. The physical and chemical analyses of the soil were made with samples collected at 0-20 cm and 20-40 cm depths. Differences in diversity, hierarchy and dominance volume of woody plant populations were found between sites with or without the presence of rocky outcrops. The soil has a tendency for water erosion and the aluminum saturation reached values of concentration of 7.9 cmolc dm-3, with a pH value between 4.1-4.2 in rocky environments. The obtained results suggest that Q. parviflora and A. occidentale probably have some kind of resistance to the toxicity of aluminum in soil with a pH value below 5.0.