Análise de gradientes vegetacionais e pedogeomorfológicos em Floresta, Cerrado e Campo no Pantanal Matogrossense, Barão de Melgaço, Mato Grosso

• Ano de defesa: 2009
• Autor(a) principal: Ferreira Júnior, Walnir Gomes
• Orientador(a): Schaefer, Carlos Ernesto Gonçalves Reynaud
• Banca de defesa: Souza, Agostinho Lopes de , Meira Neto, João Augusto Alves
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Botânica
• Departamento: Botânica estrutural; Ecologia e Sistemática
• País: BR
• Palavras-chave em Português: Pantanal; Gradiente ambiental; Vegetação; Solos; Inundação
• Palavras-chave em Inglês: Pantanal; Environmental gradient; Vegetation; Soils; Flooding
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BOTANICA
• Link de acesso: http://locus.ufv.br/handle/123456789/356

This study was divided into two chapters. The first aims to study the different tree vegetation distributed in several parts of the landscape along the environmental gradients (flooding, pedologic and geomorphological) of the Pantanal lowlands, checking the floristic and structural changes in communities of plants. The studies were carried out at the RPPN SESC Pantanal, located in Barão de Melgaço, Mato Grosso, in the interfluve of the rivers Cuiabá and São Lourenço. Thus, transects were installed for sampling by plots of fitocenoses trees along the gradient. Each transect is 20 meters in width and length ranges from 60 to 100m. We studied areas of the Cerrado de Lixeira, Cerradão de Carvoeiro, Deciduous Forests and Cambarazal. It was found great diversity of habitats ordered along the gradient of flooding: xeric environments on levee with deciduous vegetation, low levee with savanna vegetation and lower plains and periodically flooded with monodominant forests. The species Astronium fraxinifolium had the widest distribution within the gradient. The species were characterized as the preferred location in “habitats flooded in exceptional floods or dry" and "floodedhabitats” and” widely distributed along the gradient of flooding”. The diversity of species showed a direct relationship with level of flooding. The Cerradão Alto de Carvoeiro of the lower levee was interpreted as a transitional physiognomy for the deciduous forests of the levee. The Deciduous Forests of Aroeira as a fácie of the Deciduous Forests because of greater floristic and structural similarity with those. The second chapter aims to study the variations along the soil gradient vegetation and understand the role of soils in phytophisiognomy differentiation in areas subject to the same regime of flooding. Moreover, it is the opening of profiles in each area studied and the collect of soil for analysis. Were also collected samples of surface soils in the plots along the gradient. Linear regressions were established between community parameters and soil variables to elucidate the determination pedological aspects on the structure of communities. Canonical Correspondence Analysis (CCA) and Spearman Correlations were used to verify the role of soil attributes in spatial arrangement of communities and populations of tree species. The different vegetation samples are strongly associated with soil and form gradients. We studied the following geomorphological units: seasonally flooded plains, levees, lower levees, internal canals and natural drainage canals. The Earth Mounds and Cambarazais occur in seasonally flooded plains, the Deciduous Forests and the Cerrado de Lixeira recover the levees and the Cerradões de Carvoeiro in the lower levees. The main processes of formation of the soils are hydromorphic and podzolization. The pH, the levels of P, Ca2+, Mg2+ and K, the base saturation and P-rem increase and aluminum saturation decreased from seasonally flooded plains toward the levee. The soils of Deciduous Forests of the levee represent environments with natural soils of higher fertility, less acidity and lower aluminium. The soils of Cerradões de Carvoeiro of the lower levee are dystrophic, aluminic, sodic and high acidity, very similar to the Cambarazal soil, where the latter provides a lower natural fertility than those. The soil of the Cerrado de Lixeira is dystrophic and has medium acidity. The Eatrh Mounds are dystrophic, aluminic, sodic and sometimes with high acidity and, with the trend that the more sand, more dystrophic, acid and aluminic. The richness of species showed positive correlation with the P-rem. The abundance showed a positive correlation with the P-rem, P and V%. The basal area was correlated positively with V% and negatively with Al3+. Differences in natural fertility and the levels of aluminum and sodium in soils were the main responsible for the observed variation phytophisiognomy.