Diversity and patterns of spatial distribution of species of natural regeneration in São Francisco de Paula, RS, Brazil

Abstract

This work aimed the analysis of floristic diversity and spatial distribution of species of natural regeneration in an area of Mixed Rainy Forest in the National Forest of São Francisco de Paula, RS, comparing different diversity and dispersion indexes. The vegetation sampling was performed by analyzing 180 subunits of 10 m x 10 m, with all the individuals taller than 1.30 m and with breast height circumference from 3.0 cm to the limit of 29.9 cm, considered as natural regeneration. The parameters of frequency and density, dispersion indexes of MacGuinnes, Fracker and Brischle and Payandeh, and different alpha indexes of diversity were calculated. The dispersion indexes revealed the same behavior for the species, which are aggregated or presented a tendency to cluster. Margalef index was underestimated, possibly influenced by the size of sample unit. The Menhinick and Shannon indexes represented the diversity in a very real form, even in small sampling units. The indexes of Simpson and MacIntosh denoted low dominance and the equity indexes revealed high uniformity in species.