Sucessão ecológica em fragmentos florestais serranos, Paraíba, Brasil

ABSTRACT: It aimed to study floristics and tree-shrub structure in mountain forest fragments with different successional stages, Paraiba, Brazil. The fragments were grouped: Group I - fragments with 15 years (F1 and F2); Group II - 25 years (F3; F4); Group III - 35 years (F5; F6). It was randomly plotted twelve parcels, measuring 10 m x 20 m, totalizing 72 sample units, or 14.400 m2. Were sampled all the shrub-tree individuals with diameter at the breast height (DBH) ≥ 5 cm. The Mata Nativa Software was used comparing the floristic similarity between the areas and PC-ORD for Cluster Analysis Dendrogram, assembling qualitative matrices and using the Jaccard Index (UPGMA) as a Coefficient. Were recorded 3.018 individuals belonging to 29 families, 54 genera and 57 species were registered, with Group I showed 922 individuals distributed in 22 families, 33 genera and 34 species, Group II with 1,025 distributed in 28 families, 48 ​​genera and 50 species and in the Group III 1,071 individuals belonging to 28 families, 51 genera and 53 species. The species with biggest VIs were Tapirira guianensis (Cupiuba) and Thyrsodium spruceanum (Caboata Branca) The Groups II and III showed the biggest values for the diversity index (H' = 3.12 and 3.5, respectively). The results show floristic and structural differences between the studied fragments, as a consequence of the ecological successional process. KEYWORDS: Mountain forest, Ecological succession, Phytossociology.