EFEITO DA BORDA SOBRE A ESTRUTURA E DISTRIBUIÇÃO ESPACIAL DA REGENERAÇÃO NATURAL EM UMA COMUNIDADE ARBUSTIVO-ARBÓREA DE UM FRAGMENTO DE FLORESTA OMBRÓFILA ABERTA NO MUNICÍPIO DE AREIA, PARAÍBA

Abstract

The isolation forest endangers the survival of certain species, destabilizes the mechanisms of natural regeneration compromising future offspring that instability leads to ecosystems. Aiming to contribute to conservation plans and / or management of forest fragments present study evaluated some physical factors (Brightness, Edge Distance and Width) and biological (number of individuals, species richness, Shannon-Wiener diversity and Equability of evenness) in different areas of a plant community in regeneration stage II on the campus of the Federal University of Paraíba in fragment classified as transitional between Rain Forest Open Sub-Montana and Montana. We sampled all individuals with height greater than 50 cm in height and circumference at breast height (CBH) less than ten centimeters. In an area of 3000 m² 1848 individuals were inventoried inventoried, distributed in 48 species, 42 genera and 29 families taxonomic and two unidentified morphospecies. The highest number of species occurred in the families Leguminosae Mimosoideae (Albizia polycephala, Piptadenia cf. Viridiflora and Inga vera), Melastomataceae (Miconia hypolenca, Miconia and Tibouchina candolleana albicaus) and Sapindaceae (Allophylus laevigatus, Cupania revoluta and Talisia esculenta). Protium heptaphyllum had the largest number of individuals and also had higher dominance, cover, basal area, importance value and natural regeneration. The diversity index of Shannon - Wiener found in this study was 1.86 and evenness (J) was 0.76. The index McGuinness (IGA) showed that 49% of surveyed species tend to cluster. The similarity index showed qualitative and quantitative occurrence of similar random groups, with no significant difference between the edge and central portions. There were also significant in multivariate analysis of physical and biological factors. But the analysis of variance showed that there were statistical differences between the edges and in accordance with the spatial distribution of species the width of the fragment was positively correlated with wealth. It is concluded in this study that the fragment is any of the surround effect, but one of the regions has become more degraded probably due to the removal of vegetation crops for pasture and necessitating maintenance plan for that remaining to protect the floristic diversity of interactions with the biotic and abiotic factors acting.