Levantamento da vegetação arbustiva arbórea de um fragmento de Caatinga, localizada em Castro Alves-Ba

Abstract

This study aimed to conduct the survey in phytosociological Caatinga sensu stricto, in the municipality of Castro Alves-Ba and define optimum size of plots for the study area. To obtain the data area 14 there was systematically divided into four plots of 10 x 200 (2000 m2). Each plot was subdivided into 80 plots of 100 m2, a total sample area of 8000 m2. All individuals were measured with a diameter at ground height (DAS) equal to or greater than 3 cm and collected samples of plant material of all trees measured for identification. To describe the tree community structure were calculated by species, relative density, relative frequency, relative dominance, importance value index and value index coverage. We also calculated the Shannon diversity index (H ') and evenness (J') and constructed graphics diameter distribution. To define the optimum size of plot was used the analytical method of species area curve. The species that had a higher IVI was Poincianella bracteosa Tul. L. P. Queiroz, comb. Nov., Capparis then YCO Mart. & Eichler, Senegalia bahiensis (Benth.) A. & LPQueiroz Bocage and pyrifolium Aspidosperma Mart. Regarding diversity, Shannon index (H ') was 2.1 nats.ind-1 and evenness (J') was 0.5737. The Caatinga sensu stricto studied, had a pattern of diameter distribution in the form of inverted J, which is expected for native vegetation. But the species, Capparis YCO Mart. & Eichler, did not follow the same pattern of distribution of the community in general. The optimum size of plot, defined by the analytical method of species area curve, was 5001 m2.