Análise estrutural e estado de conservação em um remanescente de Caatinga no Rio Grande do Norte, Brasil

Abstract

The present study is an investigation of woody vegetation through a phytosociological inventory on a remnant of caatinga vegetation in Rio Grande do Norte. This search aimed to characterize the woody caatinga vegetation with different interferences. The study was conducted at Fazenda Cauaçu, municipality of João Câmara, micro-region of Baixa Verde, in a fragment of caatinga with 700 ha. 20 plots with 10×10 m which one were allocated and 10 plots in different historical use sites (A1 e A2) more than 100 m away from each other. All woody plants with stem diameter at ground level (DNS) ≥ 3 cm and total height ≥ 1m were inventoried. From the data collected was used to calculate diversity, equability and similarity indices. It was inventoried in total of 3,107 individuals in 23 families, 40 genera and 45 species. That total 86.7% of the species were identified to the species level, 11.1% at the generic level and only 2.2% in family. Fabaceae and Euphorbiaceae family had the highest richness, representing 42.2% of all species and was similar to that reported in other studies in areas of caatinga. The diversity index (H ') was calculated at 2.929 and 1.498 nats. ind. - ¹ in the areas A1 and A2, respectively. Among the most frequent and abundant species in the area, have excelled Croton blanchetianus Baill. and Poincianella gardneriana (Benth) L.P.Queiroz. representing 53.9% of all individuals. All species were common in A2 to A1, except “carnauba” Copernicia prunifera (Mill.) H.E. Moore, present only in the first area. For each area A1 and A2, 44 and 24 species were found, respectively. The densities were 3.312 and 4.455 ind./ha and basal area 10,498 m² and 8,267/ha, respectively. The vegetation of the area is composed of species typical of Caatinga areas and the remaining presents in good condition and areas with different levels of interference, but in natural regeneration.