Ecology of herbaceous vegetation on bancadas lateríticas (cangas) in Corumbá, Mato Grosso do Sul State, Brazil

Bancadas lateríticas are ironstone outcrops that surround Morraria do Urucum and Morraria do Rabicho. This paper analyzes the floristic composition and structure of three ironstone outcrops, in quadrats of 1 m², and reveals possible intrinsic patterns in site subsets by means of ordination analysis (detrended correspondence analysis - DCA) using cover data of plant species. A total of 66 vascular species belonging to 27 botany families were sampled. The richest families were Fabaceae (11 species) and Poaceae (9) while Selaginella sellowii and Sporobolus monandrus had the highest importance values. The ordination analysis suggested that herbaceous communities were influenced by the granulometry of the substrate, with species that occurred directly on hardened substrate and others that occurred on a thin soil layer. We emphasize the importance of the conservation of this flora, due both to its floristic insularity and to the little knowledge about the ecosystems that form the landscape mosaic of the Pantanal.

ferricrete; ferruginous geosystem; ferruginous grasslands; phytosociology