Reconstrução do histórico de distúrbios no dossel e seus efeitos na estrutura e funcionamento da Floresta Ombrófila Mista

Abstract

Trees are sessile organisms that consume resources and interact primarily with neighboring trees. Whereas many factors affect tree-growth, understand the causes of variations in growth over their tree life trajectories is very valuable information on ecology, and may have many applications. Dendrochronology provides the proper approach to the reconstruction of the long-term tree-growth variation. In this thesis, I realized a canopy disturbance reconstruction, through the analysis of tree growth surges patterns in Ombrophyllous Mixed Forests (FOM) in northeastern Rio Grande do Sul. Using morphological data from two permanent plots projects inventories we observed that the disturbance histories described were strongly related to the current forest structure. Whereas the FOM has been widely and intensively subjected to logging, and disturbance chronologies revealed synchronistic events of abrupt changes in tree growth, likely due to selective logging. I also investigate the complementarity effect on tree growth, based on functional dissimilarity between focal trees and surrounding tree communities, analyzing also the influences of disturbance histories. Positive effects of complementarity were observed in tress of A. angustifolia. Furthermore, such positive effects were dependent on the history of longtime post-disturbance stability. We also observed that Lauraceae trees occurring in intensively logged plots the complementarity effect was significant, and the growth performance of the trees depends on the responses to environmental filter.