The floristic composition of the natural regeneration in a secondary Seasonal Semideciduous Forest fragment in the Atlantic Forest domain, Southeastern Brazil, was studied in the years 1992, 1995 and 2000. The sampling unit sizes were 0.5x10m, 0.5x20m and 1x20m, respectively, for plant size class 1 (height up to 1 m), class 2 (height from 1 to 3 m) and class 3 (height > 3m and DBH < 5cm). A total of 4,149 individuals were sampled over the inventory period, comprising 42 families and 160 species, being 11.7 % pioneer, 62.1 % early secondary, and 26.2 % late secondary species. Family number did not change and number of species increased with time. Fabaceae, Myrtaceae, Rubiaceae and Lauraceae were the predominant families. Species ingrowth was higher than mortality. Shannon-Weaver diversity index was significantly lower (P < 0.05) only for the plant size class 1 as compared to the other size classes, in 1992, and it increased significantly from 3.45 (average of all plant size classes), in 1992, to 3.67 and 3.64 in 1995 and 2000, respectively. The Pielou equability index per inventory date varied from 0.71 to 0.74, and it was 0.71; 0. 79 and 0.82 for the size classes 1, 2 and 3, respectively. Overall, the results showed that monitoring the natural regeneration over an age sequence is important to understand the dynamics of the secondary forest fragments.
Natural regeneration; Semideciduous Seasonal Forest; forest fragment and floristic composition
