Relação solo-vegetação em gradientes na zona de tensão ecológica Norte de Minas Gerais e Centro-Sul da Bahia Brasil

• Autor(a) principal: Moura, Vitor Moreira
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2548
• topic: Florestas estacionais; Serra do Espinhaço; Ecótonos floresta-savana; Seasonal forests; Espinhaço; Forest-savanna ecotones; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA

The main objective of this study was to examine the nature of the forest-savanna ecotones in landscapes of the far north of Minas Gerais and Bahia South-Central, located in a context of ecological tension zones between phytogeographic domains. More specifically, quantitatively determine whether the chemical and physical properties of the surface layer of soils in these environments are correlated with the observed variations in the composition and structure of plant communities. The study areas were placed along two toposequences, the first in the Espinhaço Range in Mato Verde (MG), with the ecotone "Seasonal Deciduous Forest - Cerrado s.s. Campo Rupestre Quartizítico" the second, at Monte Alto range in Candiba (BA), with the ecotone "Seasonal Deciduous Forest Seasonal Semideciduous Forest - Campo Cerrado". It was found that the gradients studied are marked by sharp discontinuities between different vegetation types of forest and savanna at scale of hundreds of meters, the sharp changes in the structure and composition are accompanied, in most cases, fundamental changes in soil conditions. Generally a small number of species is noted when the structural parameters are considered in each area. There is a clear distinction in the structural transition between forest and open areas, with significant increase in height and diameter and average species richness. The analysis of floristic similarity in each of the localities show high dissimilarity between forest and savanna, and reveal strong internal heterogeneity. Analyses of ordering used showed that these are long gradients, where there is the distinction of species groups/plots quite discreet. We conclude that groups of plots/species sampled in forest vegetation types are related to environments with higher nutrient availability and higher CTC, with higher clay and organic matter in relation to the open areas. These environments also have deeper soils and higher proportions of silt and clay fractions that areas of Cerrado, suggesting greater water retention capacity and support communities with more complex structure. On the other hand, the group of plots / species related to savanna physiognomy presents topsoil with high acidity, high exchangeable aluminum, lower content of organic matter and nutrient availability.