Efeito da idade da floresta e da sazonalidade climática sobre os atributos da assembleia de regenerantes em uma região semiárida no nordeste do Brasil

Abstract

Several anthropogenic processes cause the degradation of dry forests, but nevertheless, they have the power to regenerate. The process of regeneration of these forests, however, can be influenced by the time of abandonment, by the type of use of the area, besides the variation of climatic seasonality. The objective of this study was to study the influence caused by the age of the forest and the seasonality in the floristic composition, richness and density of regenerants in a caatinga area. The work was developed in the Pimenteira State Park, in Serra Talhada, state of Pernambuco, in three fragments: a fragment with a regeneration age of one year, denominated field area, a fragment with five years of abandonment corresponding to the young forest and a forest Preserved for at least 30 years called mature forest. A total of 40 plots of 1x1m were installed in each of the three sampled areas, in a total of 120 plots, where all individuals of the herbaceous and woody stratum up to 1m high were considered for the regenerating community. The study was conducted between September 2015 and May 2016, where two censuses were carried out to sample the regenerating community during the dry season (September to December) and during the rainy season (January to May). Monthly all plots of the three areas were monitored for collection of reproductive material. A total of 66 species were found, being 45 in the field, 38 in the young forest and 43 in the mature forest. There was a difference in floristic composition between the fragments and between seasons. In the rainy season the field registered more species and the density was higher in the field and in the young forest. The climatic season and the interaction between season and forest age were responsible for the variations in the richness and density of the regenerants, being these two predictive variables fundamental for the establishment of the regenerating communities of the observed caatinga environments.