Estrutura da população adulta e regenerante de Cynophalla flexuosa (L.) J.Presl em área de mata ciliar degradada no semiárido Paraibano.

Abstract

This study aimed to analyze the phytosociological parameters of adult and young regenerating specimens of Cynophalla flexuosa (L.) J.Presl in a degraded riparian forest of an intermittent riparian system in the municipality of Serra Branca, Cariri region of Paraíba, Brazil. The analyses were performed from February to March 2021 and covered the degraded riparian area of the “Lagoa da Serra” stream (7°30'04.32'' S and 36°42'13.12'' W, 511 m altitude), belonging to the Taperoá River sub-basin. The study area included 50 contiguous plots of 10 x 20 m. The absolute density (AD) and absolute frequency (AF) parameters were calculated. Regeneration classes were established and frequency histograms were constructed to define the height and diameter distribution classes. A total of 255 regenerating young specimens were surveyed. Young individuals were recorded in 34 plots, representing 68% of the total sample. The mean height and diameter recorded for young regenerating specimens were 0.89 m and 1.02 cm, respectively. Considering the AD and AF phytosociological parameters per size classes of natural regeneration, class 1 had the highest values (0.05 – 0.50 m) with 118 ind./ha. Regarding the percentage distribution of individuals per size class of natural regeneration, CT1 (0.05 – 0.50 m) had the highest percentage (46.27%). Nineteen adult individuals were identified in the population, distributed in 11 plots, representing 22% of the total sampled plots. Adult specimens had mean height and mean diameter of 3.30 m and 5.61 cm, respectively. The height class II (2.1 – 3.0 m) accounted for the largest number of specimens, represented by 7 individuals sampled. Regarding the diameter classes, the largest number of individuals was found in class I (3.0 – 6.0 cm), with 16 sampled specimens, representing 84.21% of the total number of adult individuals in this class. Therefore, the data obtained from this research on the structure of regenerating young and adults specimens of C. flexuosa in degraded riparian forest areas provide important subsidies for defining plans for the management of natural resources in hydrographic basins in the context of the Brazilian semi-arid region, thus strengthening actions aimed at conserving water resources, complying with the goals 6 and 15 of the 2030 SDGs (Sustainable Development Goals).