Composição florística, similaridade e influência de variáveis ambientais de uma floresta de araucária na Serra da Mantiqueira, Minas Gerais, Brasil

Abstract

Minas Gerais state has a rich and diverse plant cover, especially in high altitude locations which are like refuges for the regional flora. The Parque Estadual da Serra do Papagaio (PESP), located in the Mantiqueira hill range, houses one of the rare fragments of Mixed Needle-broadleaved Forest (MNF) of the state, and is inserted into a mosaic of high-altitude grasslands and dense forests. This study aims at analyzing the floristic composition, similarity and the influence of environmental variables in the MNF of PESP. Monthly expeditions were done (March 2012 to June 2013) and all fertile plants (excluding epiphytes) were collected in alluvial and slope MNF areas at altitudes ranging from 1650-2000 m. We obtained, from the TreeAtlan database, information on 51 areas located above 800 m altitude in Serra da Mantiqueira, which were used in Similarity Analysis and Canonical Correspondence Analysis (CCA) of shrub/tree components. A total of 312 species was recorded, distributed to163 genera and 83 families, 292 of which were angiosperms, two gymnosperms and 18 pteridophytes. The richest families were Asteraceae (49 spp.), Melastomataceae (33 spp.), Rubiaceae (16 spp.), Solanaceae (15 spp.) and Myrtaceae (13 spp.). The richest genera were Leandra (14 spp.), Solanum (11 spp.), Baccharis (9 spp.), Myrcia (8 spp.) and Tibouchina (8 spp.). We also found two threatened species and six new records for Minas Gerais state. We observed the presence of temperate climate species that are also frequent in others montane and upper montane forests in Southeastern Brazil and in the Andes, stressing altitude as an important factor in floristic composition. The CCA showed a higher correlation with the winter precipitation and with altitude. The similarity analysis showed a greater resemblance to Broadleaved dwarf-forest from Serra Fina, Serra Negra and Agulhas Negras, probably associated with shared high altitude species and geographical proximity among these areas, indicating that the MNF of PESP receives influences of the local flora and not presents the floristic pattern of other MNF in the Mantiqueira hill range.