Phytogeographic patterns of Mimosa (Mimosoideae, Lguminosae) in the Cerrado biome of Brazil:an inicator genus of high-altitude centers of endemism?

摘要

The objective of this study was to elucidate phytogeographic patterns of Mimosa in the Cerrado biome and assess their usefulness in conservation. We recorded 189 species of Mimosa, 74% restricted to the biome and 26% in other areas; 8% are endangered. Grid rectangles of 1deg x 1deg 30' within continuous Cerrado were scored for Mimosa species. Similarity matrixes using the Jaccard coefficient were assessed using UPGMA clustering and nonmetric multidimensional scaling; this produced 12 floristic provinces. Centers of diversity overlapped with centers of endemism at the spatial scale of this analysis; 48% of the species are narrow endemics and were regitered to 28 (22%) of the grid rectangles. Mimosa is proposed as an indicator taxon of highland plant endemism within the Cerrado, as several Mimosa-inferred centers of endemism are also major centers of highland endemism. Six grid rectangles in which floristic provinces lacking reserves coincided with centers of endemism lacking reserves,are proposedas high priorities for new biological reserves.