Restabelecimento de Araucaria angustifolia e Ocotea porosa após sete décadas da exploração florestal

Abstract

Research in the growth of tree species are very important for the management and conservation of forest remnants. Disturbances that occur in the forest are responsible for the dynamic formation of gaps, which directly influence the establishment and growth of species. Historical records and evidence showed that a remnant of 26 hectares of Mixed Ombrophyllous Forest, located in the Três Barras National Forest, Santa Catarina state, abandoned after intensive logging performed between the period 1911 to 1940, taking shape as an important remaining for growth studies of species after anthropogenic disturbances. Thus, the growth of Araucaria angustifolia (Bertol.) Kuntze and Ocotea porosa (Nees & Mart.) Barroso was measured in its base, breast height and crown insertion point and or bole bifurcation height, by partial trunk analysis, to construct growth series for each evaluated position and model the periodical annual increment in basal area (IPAG) for the last five years in the DBH. The trees were randomly selected and increment samples were taken with the use of Pressler`s borer. In the laboratory, the growth rings were measured, synchronized with the aid of COFECHA program and constructed time series. The individual tree model type was developed by stepwise procedure and the increment in basal area (dependent variable) and the dimensional variables and the competitive status of the trees, as independent variables. Statistical criteria for the selection of models were the adjusted coefficient of determination (R²aj.), Standard error of estimate (Syx) and the graphical distribution of residuals. Results showed that the thicker trees from Araucaria angustifolia and Ocotea porosa regenerated after the logging conducted, leading to the restoration of the forest. The width of the growth rings on each radial sample show a wide variation in successive years, but the growth rings formed in the crown insertion point presents more uniformity. The logarithmic transformation of IPAG and the independent variables: diameter at breast height, hegyi index and crown length, have allowed creating models describing the growth of trees under different environmental conditions.