The woody component in a Southern Sertanean Depression area, in Petrolina, Pernambuco State, Brazil

Abstract

The aim of this study was to evaluate the structure and diversity of the woody component of Caatinga in Southern Sertanean Depression, Petrolina, Pernambuco State, Brazil. We sampled 25 plots of 400 m². Total height and circumference at the soil level (CSL ≥ 15.8 cm) were measured of living or dead standing individuals, to calculate phytossociological parameters. The community heterogeneity was evaluated through detrended correspondence analyzes. We sampled 825 individuals, distributed in 11 families, 22 genera and 27 species. The families with the highest richness were Fabaceae (9 spp.) and Euphorbiaceae (5 spp.), with 51.8% of the total richness. The species with higher cover value and importance value were Mimosa tenuiflora and Poincianella microphylla, justified by their high abundances (295 and 217 individuals, respectively) and basal areas (2.95 and 1.72 m² ha-1, respectively). We found median values for the diversity and equability indices (H´ = 2.04 and J´ = 0.62), and species distribution presented better adjust to Log normal model, suggesting moderate ecological dominance of these species. The studied community was very heterogeneous, possibly due to the multiple use of the soil in the past, reinforcing the responsibility of institutions with forest remnants to establish measures for the conservation of their green areas.