Melastomataceae A. Juss. da Serra Negra, Minas Gerais: tratamento taxonômico, distribuição nas fitofisionomias e similaridade florística

Abstract

Serra Negra is part of the Mantiqueira Range, which is situated in the south of Zona da Mata region, state of Minas Gerais, near the municipalities of Bom Jardim de Minas, Lima Duarte, Olaria, Rio Preto and Santa Bárbara do Monte Verde. With altitudes between 800-1700m and vegetation characterized by a mosaic of forests, shrubby and grasslands landscapes, housing a high species richness and endemic taxa. Melastomataceae is one of the most representative families in the region, composed by 66 species and 20 genera: Acisanthera, Behuria, Bertolonia, Cambessedesia, Comolia, Huberia, Lavoisiera, Marcetia, Meriania, Microlicia, Mouriri, Ossaea, Pleiochiton, Rhynchathera, Siphanthera (monospecific); Clidemia (2 spp.); Leandra (16 spp.); Miconia (17 spp.); Tibouchina (13 spp.) and Trembleya (3 spp.). The specie Tibouchina boaraceiensis, endemic to São Paulo, was registered as a new record for the state of Minas Gerais, while Tibouchina sp. nov. is considered a new taxon to the brazilian flora and, until now, endemic to the study area. Regarding conservation, it should be highlighted the species Behuria parvifolia, Huberia nettoana and Meriania claussenii, probably threatened with extinction at regional or national levels. The forests formations had the highest number of exclusive species (22 spp.), with a prevalence of arboreal species of Miconia and Leandra, followed by Meriania, Mouriri and Tibouchina. In the shrubby and grasslands landscapes, characterized by quartz soils, prevail shrubs and subshrubs species, especially the genera Cambessedesia, Comolia, Lavoisiera, Marcetia, Microlicia, Siphanthera and Trembleya, typical of rocky fields. The Melastomataceae flora of Serra Negra has greater similarity to the Ibitipoca State Park, Minas Gerais, Itatiaia National Park, Rio de Janeiro and Forno Grande State Park, Espírito Santo. The similarity values with the rocky fields of the Espinhaço and the forest and grasslands of the Serra do Mar State Park, São Paulo are low. The autocorrelation analysis showed that the flora similarity does not decrease with the geographic distance. Heterogeneity habitats coupled with biotic factors such as germination and seed dispersion, can affect the distribution of Melastomataceae species.