VARIATION IN VEGETATION STRUCTURE IN A CAATINGA AREA IN THE YEARS 2015 - 2019
Phytosociological parameters. Dynamic processes. Conservation unit
Studies on the composition and structure of the caatinga are important for the characterization of the different faces, constituting a tool to understand aspects of regional ecology, providing bases for its conservation. The objective of this work was to characterize the floristic composition and structure of a Caatinga area between 2015 and 2019. The experiment was installed in Açú National Forest, RN. In 2015, 20 sample units of 400 m2 were implanted and all woody individuals with girth at breast height ≥ 6 cm were measured. In 2019 partial replacement of some plots occurred and all woody individuals with CAP ≥ 6 cm were measured. Between the respective years the floristic and phytosociological data were analyzed. In 2015, 2,408 individuals were inventoried, distributed in 15 families and 23 species. In 2019, 2,271 individuals were sampled, distributed in 16 families and 34 species. The species with the highest DoA were C. pyramidale (4,575 and 5,503 m2ha-1) and H. impetiginosus (2,093 and 1,621 m2ha-1) for both years. The basal area in 2015 (8.68 m²ha-1) was lower than that calculated for 2019 (9.05 m²ha-1), and the diversity index (H ') was 2.19 and 2.34 nats.ind-1 for 2015 and 2019, respectively. The diameter distribution concentrated in the first class a total of 1,936 (2015) and 1,767 individuals (2019). The volumetric increment was 4.85 m3ha-1, that is, 1.21 m3ha-1year-1. Conserved areas are prone to robust successional advances compared to disturbed areas.