The vascular plants survey of a remnant of semideciduous seasonal forest in the Atlantic Forest Biome was carried out in the ReBio do Grama, municipality of Descoberto, Minas Gerais, through forthnightly trips to collect fertile specimens between August 1999 and December 2004. The angiosperms included 644 species distributed in 370 genera and 100 families, including 6 species new to science, while the lycophytes and ferns included 64 species in 37 genera and 16 families. Fabaceae (55 spp.) was the family with the highest number of species, followed by Rubiaceae (50 spp.), Melastomataceae (28 spp.), Bignoniaceae and Orchidaceae (27 spp. each) and Myrtaceae (25 spp.). Once the survey was concluded, a comparison between it and the floristic composition of other nine areas (3 of seasonal and 6 of dense ombrophilous forest) was performed through multivariate analysis. These 9 sites were chosen as their surveys also included all angiosperm habits rather than only woody plants. Each analysis was processed for the all habits and then for each one of the following 8 habits: trees (including treelets), shrubs, climbers (woody and herbaceous), ground-dwelling herbs, rupicolous herbs, epiphytes, hemiepiphytes, and parasites. Multivariate analysis suggested that the longitudinal, latitudinal and altitudinal gradients interfere in different ways over the species richness of diverse habits. The reduced number of species shared between areas, associated to the high regional richness of certain habits shows the importance of conserving forest fragments in different geographical areas of the Atlantic Forest in order to maximize the conservation of the biodiversity within this Domain.
floristic composition; Atlantic Forest Domain; Zona da Mata
