Levantamento florístico da Mata Ciliar e das Macrófitas do Açude Grande, sítio Santa Gertrudes, município de Sousa, Paraíba, Brasil.

Abstract

Riparian forests, as well as macrophytes, play fundamental roles on the banks of aquatic bodies in the Brazilian semiarid region, acting in the preservation of biodiversity and quality of water resources, favoring the maintenance of these ecosystems. In view of this, the present study had as its main objective the floristic survey of the riparian forest and macrophytes present in the Açude Grande, located in Sítio Santa Gertrudes, municipality of Sousa - PB. For this purpose, monthly excursions were carried out between August 2023 and August 2024, to collect fertile botanical material and photographic record of the species, intended for the production of photographic planks. Subsequently, the collected material was herborized for deposit in the scientific collection of the Lauro Pires Xavier Herbarium (JPB), of the Federal University of Paraíba (UFPB). Morphological analyses for the identification of taxa were carried out in the botany laboratory of the Teacher Training Center (CFP) - Federal University of Campina Grande (UFCG), with the aid of stereomicroscope and specialized bibliographies. Then, the confirmation of the names through consultations with online databases and experts. The indication of the origin of the species and their respective geographic distribution followed the Flora and Funga of Brazil, and the International Union for Conservation of Nature for the classification of extinction risks. As a result, four species of macrophytes and 48 species in the riparian forest were recorded, totaling 52 taxa, distributed in 46 genera and 24 families, with Fabaceae (8) being the most representative family. As for the genera, Solanum (Solanaceae) stands out with three species, with a predominance of genera that presented only one species (41). Regarding the habits, the herbaceous was the most dominant (24), compared to shrubs (9), subshrubs (7), trees (7) and climbers (5), however, it is suggested that the preeminence of herbs is related to the greater number of collections of this size in periods of greater water availability. There was a considerable richness of native species (41) when compared to naturalized species (10) and species of cultivated origin (1), in addition to the significant number of endemic species (5). Regarding the risk of extinction, all the species recorded are listed as being of little concern. Regarding the geographical distribution, they present a wide disposition, since 17.3% of the species occur in all regions of Brazil, 63.5% in the entire Northeast and 94.2% are registered in the state of Paraíba, in which Borreria tenella was considered as a new record. Thus, the present work found a relevant diversity of taxa. However, It was presumed that the low rainfall and the high rate of anthropization may have interfered with the results obtained. In addition, the predominance of native species and the index of endemism show the local wealth, which has been constantly degraded. Thus, it is concluded that the results achieved provide fundamental information that, in addition to generating subsidies for new studies on the flora of the Caatinga, especially in the riparian forests, may collaborate with the development of projects for the recovery and conservation of these environments, promoting the valorization and conservation of regional biodiversity.