Aspectos ecológicos e anatômicos de epífitas vasculares da Trilha do Muriqui, Parque Estadual da Serra do Brigadeiro, Araponga, Minas Gerais

• Autor(a) principal: Pereira, Jaqueline Dias
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/358
• topic: Epífitas vasculares; Anatomia foliar; Parque Estadual da Serra do Brigadeiro; Vascular epiphytes; Leaf anatomy; Parque Estadual da Serra do Brigadeiro; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA

Vascular epiphytes may occupy several locations along the trunk and in tree tops, becoming exposed to different conditions of light intensity, in the several extracts of the forest canopy. Studies on the preferences of epiphytes have been carried out by different extracts of the canopy, but data about leaf anatomy and ecophysiological aspects of these species are scarce. The epiphytic habit involves several adaptive strategies in response to the different kinds of stress to which these plants are exposed, mainly water and nutritional stress, which are usually evidenced by their leaves. The study was carried out in a remaining Atlantic Forest area, in the Trilha do Muriqui, Parque Estadual da Serra do Brigadeiro, Araponga, MG. The objective was to identify the species of epiphytes in ten phorophytes, verify the possible relations between the characteristics of the phorophyte (cork rugosity, height) and the community of epiphytes installed in it, as well as to characterize the leaf anatomy of all the species and analyze the leaf micromorphometry in individuals of the same species along the vertical stratification. Ten phorophytes with circumference at the breast height superior to 50 cm with the highest quantity of epiphytes were selected. The fertile botanic material from the phorophytes and epiphytes was placed in the Herbarium VIC. The light measurements were carried out with the use of a quantum sensor and the measurements of temperature, air relative humidity, altitude, evaporation rate and wind speed were performed with the use of a Kestrel device. The cork rugosity was classified by observations in the field and the analysis of digital photos of the trunk of each phorophyte. Samples with 0,5 cm2 from the apical, median and basal regions of expanded leaves were selected; the material was processed and stained for anatomic evaluation, according the specific methodology for the mounting of permanent laminas. Cross and longitudinal cuttings, diaphanizations and epidermal dissociations were carried out in 23 species of epiphytes, besides the histochemical tests performed for some species. The Anati Quanti software system was used for the leaf micromorphometry of seven species which were present along the vertical stratification. The image digitalization was carried out in a photomicroscope. The micromorphological evaluations were carried out in the median region of the expanded leaves. Twenty-five species of vascular epiphytes were found, distributed in 17 genera and nine families, with the predominance of monilophytes. The phorophytes were distributed into eight species, eight genera and six families. There was not any epiphyte-phorophyte specificity, but some species are more restricted to extremely shaded locations. Vriesea heterostachys was the generalist species, which could be found in all the phorophytes, along the vertical stratification. Most species presented unistratified epidermis, except for the species of Peperomia, which presented multistratified epidermis. The presence of aquiferous hypodermis was verified in the species of Bromeliaceae and Orchidaceae. Other xeromorphic characters were observed, such as the external periclinal wall and compact mesophyll, besides the aquiferous tissues. In general, the micromorphometric evaluations tended to present a thicker mesophyll for the individuals exposed to more luminosity, but there was not a delimited tendency in the individuals exposed to intermediate regions of luminosity. Rare species were found, such as Cochlidium punctatum and Sinningia cooperi. The data of this work can contribute for the knowledge of epiphytes, which are very important for biodiversity preservation, besides providing ecological and anatomic data along the vertical stratification, which are rare in literature, and subsidies for handling and preservation of the Parque Estadual da Serra do Brigadeiro, an important remaining forest area.