Vegetation structure as an indicator of disturbance and resilience in a conservation unit in the Atlantic Forest

Considering the changes in the Atlantic Forest biome, this study aimed to investigate possible variations in the structure and composition of shrub-tree communities in three sectors of an Atlantic Forest fragment located in the municipality of Arez/RN, Brazil. Twenty-five 20 m x 20 m sampling units were allocated, dividing the remainder into three sectors (SA, SB, and SC) according to the different degrees of conservation observed. A total of 784 individuals belonging to 24 families and 53 species were inventoried. Sector SA presented the lowest diversity index, whose conservation status was considered from low to moderate, and was associated with disturbance by a recent fire. Sector SB, despite having the greatest richness and diversity, was considered to have a lower degree of conservation, due to the ease of access by the community, greater number of trails, and occurrence of gaps. The SC sector had greater equability, with a high state of maturity. The cluster analysis (presence and absence, abundance, and dominance) showed a clear separation between the SA and SC sectors and the sharing of species with SB. Only the SA and SC sectors presented indicator species and, regardless of the reported disturbances, resilience was observed through the introduction and colonization of pioneer species and the consequent increase in richness and diversity. © 2022 University of Sao Paolo. All rights reserved.