Diversity and Structure of Adult and Regenerating Arbor Component in Forest ‘Submontana’, Paraíba-Brazil

Abstract

The objective of this research was to study the diversity and similarity profiles of vegetal species from adult and regenerating arboreal component in 'submontana' forest area, evaluating the modulation of the effective numbers of vegetal species on the different strata. An area of 4400 m 2 was sampled in a remaining rainforest (Open Ombrophylous Forest), in which woody species of adult stratum and regenerating were measured. All woody individuals were considered among the adult strata with CFG ≥ 10 cm in circumference (circumference of the trunk at 30 cm from the ground). Regenerating components were measured in the same plot (CFG < 10 cm), to justify richness and diversity comparisons in the same scale of the area. The numbers of effective Hill diversity (qD) to Shannon entropy, Simpson and species Richness was estimated by rarefaction (P = .05). The effective plant species numbers (qD) were estimated at 71.00; 37.48 and 25.31 species in relation to adult stratum, and 69.0; 25.36 and 16.87 species for the regenerant. No significant differences were found for richness of species among the strata. On the other hand, when plant species abundances were intensified as more important in the diversity measures, it was proved that the tree component began to maintain greater diversity, by Shannon and Simpson's entropy. The pattern of proportionality in species abundance changed systematically as the community directed its development to the adult stratum. The hypothesis on floristic similarity was confirmed, indicating reasonable perspectives on the regeneration power of these forests, front of the great scenario of moderate local disturbances.