Diversidade florística de campos rupestres em inselbergs areníticos nos campos sulinos

Abstract

Grasslands occur extensively in South America in subtropical and temperate latitudes, respectively, in the Patagonic and Pampean biogeographic provinces. In Rio Grande do Sul, grasslands consist of a dominant phyto-physiognomy, covering 63% of the State's surface and in Brazil representing 2.07% of the national territory. The present study gathers data collected in four sandstone inselbergs of the metropolitan region of Porto Alegre, within a dense urban matrix. The floristic survey resulted in 210 native species of vascular flora. Differences in the composition and abundance of species among the inselbers suggest the existence of environmental and historical factors in the spatial distribution of species in the vegetation islands. Given the low floristic similarity among the sites and the expanding urban matrix, attention must be paid to protect these inselbergs in order to conserve the regional biodiversity.