Melastomataceae Juss. no campo rupestre do Parque Estadual do Itacolomi, Minas Gerais, Brasil: relações ecológicas, fitofisionômicas, padrões de distribuição geográfica e comparação florística

• Autor(a) principal: Rolim, Thiago Prates
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2535
• topic: Melastomataceae; Campo rupestre; Florística; Relações ecológicas; Distribuição geográfica; Similaridade; Melastomataceae; Rock field; Floristic; Ecological relationships; Geographic distribution; Similarity; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA

This study aimed to carry out a floristic survey of Melastomataceae species occurring in Itacolomi State Park (PEI), southeastern of Minas Gerais, to assess the geographic distribution of Melastomataceae species occurring in the Rock Fields of PEI and the floristic similarity with other areas of Rock Fields in Minas Gerais and Bahia. The park is part of the Espinhaço Range, a moutain complex, between coordinates 20º22'-30'S and 43°22'-32'W, with altitudes varying from 900-1772 m. The survey of Melastomataceae species was conducted by 21 monthly field trips, in 11 tracks (1. Estrada de Baixo; 2. Estrada de Cima; 3. Morro do Cachorro; 4. Calais; 5. Tesoureiro; 6. Baú; 7. Lagoa Seca; 8. Pico do Itacolomi; 9. Sertão; 10. Serrinha; 11. Caboclo), from August 2009 to February 2011, comprising eight phytophysiognomies (Wet Grassland, Scrub on Quartzite 2, Scrub on Quartzite 1 , Dry Grassland, Scrub on Phyllite, Quartzitic Fields of Rock Outcrops, High-Altitude Wet Grassland and Ferruginous Fields). In addition to the botanical material collected, Melastomataceae vouchers collected in the park that were reported in the literature or deposited in herbaria were also considered in this study. Species identification was based on specialized literature, access to specialists and visits to the herbaria BHCB, HUFU, OUPR, RB and VIC. Patterns of geographic distribution were obtained through adaptations of patterns already established. The floristic comparison was determined on the basis of studies carried out in 17 rocky field areas of Bahia and Minas Gerais.  Melastomataceae are represented in PEI by 72 species, from which an identification key was developed.  The tribe Microlicieae was the most representative, with 31 spp. The most representative genera were Microlicia (17 spp.), Tibouchina (13 spp.), Leandra (10 spp.), Miconia (9 spp.) and Trembleya (6 spp.). The species Tibouchina cardinalis, Cambessedesia hilariana, Marcetia taxifolia and Trembleya parviflora occurred in seven of eight vegetation types sampled. Most species (70%) occurs in up to four phytophysiognomies. Among the phytophysiognomies, the Quartzitic Fields of Rock Outcrops and High-Altitude Wet Grassland were the most similar vegetation types in the cluster analysis, with 52%. The most species-rich phytophysiognomies were the Dry Grassland (36 spp.) and the High-Altitude Wet Grassland (35 spp.). Six geographic distribution patterns were determined: Neotropical Pattern; South American Pattern; Western-Central-Eastern Brazil Pattern; Central-Eastern Brazil Pattern; Southeastern Brazil Pattern; and the Endemic Pattern of Minas Gerais. Most species (85%) have distribution restricted to Brazil; 48% belong to the Endemic Pattern of Minas Gerais; 34% to the Central-Eastern Brazil Pattern; 15% to the Southeastern Brazil Pattern and 3% to the Western-Central-Eastern Brazil Pattern. The Neotropical Pattern was observed in 7% of species and the South American Pattern in 8%. The species Microlicia glazioviana and Trembleya calycina are represented by small populations and must remain in the Endangered category. Behuria glutinosa, Leandra dendroides, Tibouchina canescens and Tibouchina gardneriana had the first record of occurrence in the Cerrado domain. The floristic comparison among the 17 areas showed low similarity, with the vegetation of Minas Gerais being floristically different from that found in Bahia. The maximum similarity was found between the areas of Pico das Almas and Rio de Contas, with 50%; the flora of the Itacolomi State Park proved to be most similar to that of Ouro Branco Mountains, with 34% similarity. Sixty-five percent of the species surveyed are also mentioned for the Atlantic Forest, showing the influence of this biome in the composition of the rupestrian flora of the park.