Fisionomia e estrutura de um remanescente de floresta estacional semidecidual de terras baixas no nordeste do Brasil

摘要

A quantitative survey was carried out in a seasonal lowland forest at "Esta??o Ecológica do Tapacurá" in the municipality of S?o Louren?o da Mata, Pernambuco. The aim of this study was to identify the relationship between the study area and other forests in the region. In the study area (8o03'04''-8o03'53''S and 35o09'55''-35o10'48''W), altitudes range from 100 to 140 m average annual rainfall is 1,300 mm. All live or standing dead individuals with DBH > 5cm were sampled within 50 plots (10 × 20 m). Seven quantitative surveys were selected in order to compare the regional forests using multivariate analysis. Eighty-eight species, including three undentified taxa, were sampled. Most species present simple (68.2%) and mesophyllous (76.1%) leaves. Total density, total basal area, height and medium and maximum diameter were 1,145 ind.ha-1; 23.9 m2.ha-1; 10.73 m (± 4.67); 32 m; 13.14 cm (± 6.98) and 77.35 cm, respectively. Most important species of understorey (plants shorter than 8 m) were: Gustavia augusta (Lecythidaceae), Actinostemon verticillatus (Euphorbiaceae) and Psychotria capitata (Rubiaceae). In the middle storey (17 to 20 m) Chamaecrista ensiformis (Fabaceae) was important, while in uperstorey (above 26 m), Pterocarpus rohrii (Fabaceae) and Tabebuia serratifolia (Bignoniaceae). Considering the physiognomic and structural aspects as well as the results of multivariate analyses, it is possible to note that the seasonal lowland forest studied is more related with ombrophilous lowland forest than the seasonal montane forests in the region.