Mudanças nos atributos fitossociológicos de uma floresta tropical sazonalmente seca em regeneração

Abstract

It is already known, thanks to recent work on flora and fauna inventories, that contrary to what was thought, tropical dry forests hold great biodiversity. As regenerating forests are considered the forests of the future, it is important to observe their regeneration process in anthropic areas and how the dynamics of their communities take place. Thus, the objective of this work was to verify, in three inventories with intervals of five years between them, the dynamics of the plant community of woody species above ground in a forest that underwent clear cutting. The first inventory was carried out in 2008, by Lopes (2012), when the forest had 13 years of regeneration. The second inventory was carried out in 2013, by Andrade (2016). Finally, the third took place in the execution of this work, 2018, when the forest reached 23 years of regeneration. To fulfill the objectives of this research, 200 plots of 50 m² were set up in an area that was cleared without the use of fire or pesticides. Within these plots, all individuals with a diameter at ground level ≥ 3 cm were inventoried - taking the DNS, height and identification -; compared the floristic composition and seen the effect of time on forest attributes. We hypothesized an increase in richness and diversity and a reduction in density. The results showed a slight difference, although not significant for species richness, which decreased with time, diversity, however, was similar in the first two inventories, but had a significant reduction in the last one, such facts can be justified by the strong differences in the precipitation index that preceded each inventory. The floristic composition showed significant differences. For the attributes of density, height and diameter there was a significant effect of the action of time, during the 10 years of monitoring, where the height and diameter increased and the density decreased between the first two inventories and increased again in the last one, a fact also justified by precipitation. We conclude that clear cutting without damage to soil properties ensures rapid regeneration, although this is influenced by environmental agents. Data from the three surveys, spaced five years apart, created estimates that can be used in areas with similar backgrounds.