Estrutura e mortalidade de uma vegetação arbustivo-arbórea em uma área de caatinga em Santa Terezinha - PB.

Abstract

Structure and mortality of a shrub-tree vegetation in a caatinga area in Santa Terezinha - PB. This work had how objective to know the structure floristic, phytosociological and the mortality in an area of Caatinga at Fazenda Tamanduá, Santa Terezinha - PB. Fifteen plots of 20 x 20 m in an area of 185 hectares were randomized, all of individuals that showed CBH (Circumference to Breast Height ) ≥ 6 cm were measured. Frequency, density, dominance, importance value and coverage, diversity indexes of Shannon-Wiener (H) and Pielou Equability (J) were calculated, as well as the dynamic structure, vertical and vitality of the settlement. A area contains 2.076 ind.ha-1, distributed in 19 species and 10 families being the more representative the Fabaceae and Euphorbiaceae. The indices of Shannon and Pielou were 2.00 and 0.68. The average height for the settlement was 3.34 m and the base area was 9.88 m².ha-1. A species with the highest value with relative importance was the Poincianella pyramidalis. The diametric and height classes I, with respectively (2 —|6 cm) and (1,3 —|3,3 meters) obtained larger numbers of individuals. The species Croton blanchetianus obtained the highest mortality rate followed by the species Piptadenia stipulacea. The species Amburana cearensis, Anadenanthera colubrina, Commiphora leptophloeos, and Ziziphus joazeiro concentrated them selves in the first diameter class, thats indicate one development of the ecological succession in the studied area.