RELAÇÕES BIOMÉTRICAS E AMBIENTAIS NO INCREMENTO DIAMÉTRICO DE Araucaria angustifolia NO PLANALTO SERRANO CATARINENSE

Abstract

This study analyzes the relation between biometric, environmental and morphometric variables and the average annual increase in the diameter of a native forest of Araucaria angustifolia in Lages, SC state. To do so, we used dendrochronological data obtained from 121 dominant and competitor trees. The trees were separated into three diametrical classes, ranging from 10 cm to 29.9 cm (C1), 30 to 49.9 cm (C2) and above 50 cm of DBH (C3). The database was formed by a matrix with 121 trees and 23 environmental, dendrometric and morphometric variables, which included flow direction, flow accumulation, solar radiation, face of insolation, slope, altitude, average diameter increment, diameter at breast height, height, distance (dominant/competitive), canopy rays in the north, south, east and west, basal area, age, average ray of canopy, canopy diameter, canopy area, average diameter increment by geographic direction. These variables were obtained using the algorithms from the Digital Elevation Model of the area. The relations were interpreted based on the results of multivariate analysis, using Cluster analysis, factor analysis and principal component analysis. The trees had diameters ranging from 10 and 87.6 cm and heights between 5.3 and 21 m, with average annual increment in diameter of 0.708 cm, with an average of 40 in retrospective analysis. Together with the use of these techniques, we were able to distinguish two groups and six different factors that explain 81.5% of the variance, being formed by morphometric and biometric characteristics of the increment and the relationships with environmental variables. The techniques of multivariate analysis can be applied to aid the decision-making in forest management, because they proved the correlation between the average increment in diameter (essential to compose the forest cutting cycle) and its relation to environmental factors, index form, space and dimension of individuals.