Dinâmica de espécies lenhosas em área de caatinga, Floresta-PE

Abstract

The objective of this study was to analyze the dynamics of the woody vegetation, among 2008 and 2012 in an area of Caatinga in Floresta – PE, submitted to clearcutting 24 years ago. The research was conducted at fazenda Itapemirim in an area of 50 ha, which in 2008, were installed, georeferenced and measured all the woody plants of 40 permanent plots of 20 x 20m and remeasured in 2012, to evaluate the dynamics of the community. For the inclusion criteria were considered trees with circumferences at 1.30m above ground level (CAP) ≥ 6 cm, and its bifurcations. The parameters remeasured were: density, frequency, dominance, coverage value (CV) and importance value (IV), Shannon diversity index, Pielou evenness, periodic increment (PI) and periodic annual increment (PAI), ingrowth, mortality and gross and net growth. The results showed that the floristic composition and diversity of woody species remained basically unchanged, and close to the values found in areas of Caatinga in the same region with no history of disturbance. According to the results presented in relation to structural changes were few differences among the years 2008 and 2012, except for the absolute dominance that increased considerably despite the severe drought periods, especially for the species; Poincianella bracteosa, Mimosa ophthalmocentra, Pityrocarpa moniliformis and Thiloa glaucocarpa that presented higher values of CV and IV. The PI and PAI presented in diameter and basal area for each species showed positive gains for almost all species after a period of four years. It was observed that the ingrowth exceeded mortality, in the Pityrocarpa moniliformis and Thiloa glaucocarpa. However, in terms of basal area, it is concluded that the vegetation is far from reaching its initial stock, as compared to other areas of Caatinga no history of disturbance.