Estudo do componente arbustivo-arbóreo em ecossistema ciliar degradado no Cariri Paraibano.

Abstract

Floristic composition should be one of the first aspects to be analyzed in forest areas. Knowledge of the flora is essential for studies on the structure and dynamics of vegetation, thus contributing to the conservation, recovery and management of ecosystems. In this sense, the study aimed to analyze the floristic composition of the shrub-tree component in degraded ecological systems in Caatinga areas in the semiarid region of Paraíba. The activities were supported by the analysis of maps and vegetation maps and exploratory excursions to select the areas to be sampled. The shrub-tree vegetation collections were carried out monthly from January 2017 to January 2018 and were processed in an unsystematic way, that is, through random walks along the studied streams. Thus, 37 species were recorded in the tree-shrub component of the riparian areas of Riacho Verde (RV) and Riacho Grande (RG), distributed in 12 families and 31 genera, being the predominant tree life form. The largest number of species occurred in Riacho Verde (29) and the families with the highest number of species were Fabaceae, Euphorbiaceae, Anacardiaceae and Cactaceae. These families, together with Apocynaceae, also had the highest number of genera, and in half of the families only one genus was recorded. In relation to the presence of the species in both environments, a total of 20 common and 17 exclusive species were obtained, nine of which occur in stream Verde and eight in stream Grande. It was also recorded the presence of six exotic species, of which Calotropis procera (Aiton) W.T. Aiton and Prosopis juliflora (Sw) DC. occurred in the two streams. In general, the ciliary vegetation of the sampled environments was composed mostly by species of occurrence in the Caatinga. In addition, the presence of exotic species has demonstrated the high degree of anthropization and degradation found in riparian environments in the Biome.