A flora de bromeliaceae no Parque Nacional do Caparaó, MG/ES: tratamento taxonômico e influência das variáveis climáticas na composição de espécies no sudeste brasileiro

Abstract

The Bromeliaceae family is composed by 58 genera and approximately 3172 species and distributed almost exclusively in the neotropical zone. Brazil is an important representative of the diversity of bromeliads with 42 genera and 1207 species, where 85% of these taxa are endemic to its territory. Two environment are particularly important for the family in Minas Gerais state, due to the number of endemic species: campos rupestres and campos de altitude. However, the floristic survey about this family do not include these areas satisfactorily. The aims of this study are: 1) Conduct the floristic surveys and taxonomic treatment of Bromeliaceae species in Caparaó National Park, an area of campo de altitude located on the border between Minas Gerais and Espirito Santo states (Chapter I), 2) to understand the distribution patterns of Bromeliaceae species in the mountains of southeastern Brazil and assess the influence of climatic variables on species composition (Chapter II). The floristic surveys were done in the area between September 2010 and October 2011. The material were deposited in the herbarium BHCB of Federal University of Minas Gerais. Each species identified was described, and were developed identification keys and illustrations. For the floristic analysis were compiled floristic surveys of 18 areas with an altitude above 800 m, located in southeastern Brazil. Analysis of similarity, ordering and multiple regressions were done. The Caparaó National Park presented 45 bromeliads species distributed in 11 genera, being Vriesea (16 species), Aechmea, Neoregelia and Nidularium (five species each) the most diverse genera. The subfamily Bromelioideae was the most representative with six genera and 21 species, followed by Tillandsioideae (three genera/20 species) and Pitcairnioideae( two genera/4 species). The floristic matrix included 199 species of which 80% were registered in less than three locations. The species composition is influenced by the precipitation seasonality (9.1%) and mainly by the interaction of climate variable with spatial structure among the studied areas (61.9%). Areas belonging to the rain forest were grouped and were gradually replaced by areas included in the cerrado, showing a gradient in the direction of increased seasonality of precipitation.