Floristic and taxonomic diversity of angiosperms in several vegetation types of the Caatinga Phytogeographic Domain

Abstract This study describes the angiosperm composition of four natural (Crystalline Caatinga, Rupestrian Grassland, Rocky Outcrop, Tropical Rainforest) and three anthropized (Aquatic Ecosystem, Crystalline Caatinga, Tropical Rainforest) vegetation types within the Caatinga Phytogeographic Domain, and compares habit diversity and the richness of Brazilian endangered, native, and exotic species. A total of 428 species across 85 families and 296 genera were identified between 2018 and 2020. Species richness varied from 11 to 191 among vegetation types, with natural Crystalline Caatinga (191) and natural Tropical Rainforest (129) being the richest. The ranking of families and genera by species richness differed among vegetation types. Notably, 84.35% of the species were unique to one vegetation type, highlighting their distinct compositions. Subshrub/shrub and Herb species (together) were predominant in natural Crystalline Caatinga (105 spp.), Rupestrian Grassland (20), Rocky Outcrop (20), and anthropized Tropical Rainforest (9). Tree and subshrub/shrub species were prevalent in natural Tropical Rainforest (79), while Herb species were predominant in Aquatic Ecosystem (25). The percentage of native species ranged from 87.43% to 96.67% in natural vegetation and from 72.73% to 91.67% in anthropized vegetation. Forty-five of the species, including Lafoensia glyptocarpa, are endangered, with prevalence in natural Crystalline Caatinga and natural Tropical Rainforest.