Analise silvigenica em floresta estacional semidecidua e em cerradão no estado de São Paulo / Silvigenic analysis in seasonal semidecidous forest cerradão in the state São Paulo, Brasil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Studies of silvigenic mosaics based on the analysis of tree architecture, presumed to represent reations to the stimulus due to the light entrance in the forest canopy, have been suggested to investigate the mechanisms involved in the construction of tropical forests mosaic patterns. The identification of the eco-units (patches of trees of same architectural category representing forest regeneration phases) that constitute the silvigenic mosaic considers the architectural characteristics of its component trees such as the presence or absence of reiteration, the total height of the tree and of its clear bole, and evidences of senescence. Moreover, some characteristics are presumed to indicate the light conditions under which the trees should have reiterated (tree height compared to forest canopy middle height, and to the individual morphological inversion point). To map the silvigenic mosaic, a line interception method to inventory the canopy trees was proposed and initially applied to an evergreen tropical forest. Considering that the Seasonal Semideciduous Forest has its light regime determined by a seasonal leaf fall of 20% - 50% of its species, and that the Cerradão has a relatively open canopy, the biological meaning of the silvigenic mosaic produced by that method is still not understood for these forest types. Aiming to contribute to the biological interpretation of silvigenic mosaics obtained by this method, it was applied in two areas with 5,12ha each, one in a Seasonal Semideciduous Forest in the Ecological Station of Caetetus (Gália, São Paulo), and the other in Cerradão, in the Ecological Station of Assis (Assis, São Paulo). Statistical analyses (Qui-square and adjusted residues) have been applied to verify if eco-units categories were associated to the floristic composition and/or the sucessional categories of species. Moreover, due to the premises of silvigenic analyses, it was considered important to know if and how tree architecture is influenced by other factors besides light. Therefore, the mosaics obtained in those two study areas were analyzed for the influence of soil and topographical characteristics on the distribution of eco-unit categories, by crossing the maps of silvigenic mosaics with those of soil and topography (altitude and declivity). Again, association tests (Qui-square and adjusted residues) were applied.... Note: The complete abstract is available with the full electronic digital thesis or dissertations

ASSUNTO(S)

silvigenese cerradão silvigenesis floresta estacional semidecidua montana seasonal semidecidous forest cerradão morphology

ACESSO AO ARTIGO

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