Análise dos jovens regenerantes em área de mata ciliar de caatinga degradada em riacho intermitente no Cariri Paraibano.

Abstract

The objective of this work was to evaluate the floristic composition and the structure of the young regenerating stratum in a degraded riverside area of Caatinga in the municipality of Serra Branca, Paraíba semi-arid. The survey comprised two inventories, one in the dry period (September / 2019) and the other in the rainy period (March / 2020). In the riparian area, 50 contiguous plots of 10 X 20 m were placed and in the center of each one, a 1 X 1 m subplot was plotted to evaluate the regenerating stratum. The parameters of density, frequency, dominance and importance value were calculated. Shannon's diversity index (H') and Pielou's equability index were also determined. In the two inventories carried out in the Lagoa da Serra stream, 39 species were registered, distributed in 31 genera and 14 families. The Poaceae, Malvaceae and Fabaceae families stood out in relation to the number of species and genera. The predominant growth habit was herbaceous, present in all subplots. In the dry season inventory, the species with the highest importance value were Alternanthera tenella Colla, Sida galheirensis Ulbr, respectively. and Fabaceae 1. Related to the rainy season, the species of greatest importance were Urochloa decumbens (Stapf) RDWebster., Blainvillea acmella (L.) Philipson and Boerhavia diffusa L. The values of diversity and equability were 1.22 nats.ind .-1 and 0.49 (dry period) and 2.59 nats.ind.-1 and 0.71 (rainy period) respectively. In the hypsometric and diametric distribution, it was observed in the two inventories that the largest number of individuals was concentrated in the lower value classes. Therefore, the data collected is shown to be relevant to direct strategies for the restoration of degraded riparian forests along intermittent streams in Caatinga areas, aiming at the conservation of water resources, being in grip with objectives 6 and 15 ODS 2030.