Composição e estrutura horizontal do estrato arbustivo-arbóreo em uma área de Caatinga após cortes raso e seletivo

Abstract

Located in the semi-arid region of Brazil, with a relatively large biodiversity and a high degree of endemism, the Caatinga biome has undergone an intense process of mischaracterization. Studies that aim at the importance of conservation and maintenance of biological diversity are fundamental for the knowledge of the biome. Thus, the aim of this study was to evaluate the composition and horizontal structure of the shrub-tree stratum after shallow (CR) and selective (CS) cut in a forest continuum of the caatinga in an Experimental Unit (UE), located in the rural area of the municipality of Macau / RN. For the two silvicultural treatments in 2021, four permanent plots of 20 m x 20 m were used, where each treatment has an area equivalent to 0.5 ha (100 m x 50 m) and includes two plots. All trees with CAP ≥ 6 cm were measured. To describe the structure of the tree community, the following were calculated, by species: absolute and relative density; absolute and relative frequency; absolute and relative dominance; importance value and coverage value. Shannon's diversity index (H ') and Pielou's equability (J) were also calculated. 267 individuals were cataloged, distributed in four botanical families and nine species. The families Fabaceae and Euphorbiaceae were the ones that presented the highest values of richness in the treatment of CR and CS. Pityrocarpa moniliformis was the species with the highest ecological importance and dominance in both treatments. The proximity of values was observed in their absolute frequency in the CR (600%) and CS (650%), as well as in the absolute density in the CR (1525 ni / ha) and CS (1812.5 ni / ha). The indexes of diversity and equability in the CR were H '1.4133 nats.ind-1 and J 0.7263; In CS H '1.4175 nats.ind-1 and J 0.7285. There was no significant difference between shallow and selective silvicultural treatments.