Search

This study aimed at modeling competition indices for individual trees of Araucaria angustifolia in natural forests. A total of 397 objective trees were sampled in Lages and São Francisco de Paula municipalities. Through a non-linear regression analysis, 22 distance-independent and distance-dependent competition indices were modeled based on the diameter at breast height (d) and relative height (hrel: ratio between the total height of the objective tree and the maximum potential height estimated for the same diameter). The adjusted equations of the indices according to d of the objective tree achieved values of R2 ≤ 0.546 (Syx% ≥ 15.0). The independent variable hrel improved the estimates, explaining up to 63 % of the variation in the data (Syx% ≥ 14.6). In general, competition indices - which consider in the calculation only the variables d of the objective tree, d of the competitors, its horizontal distance and eventually the height variable- showed superior performance. Therefore, they are indicated for use in growth modeling of A. angustifolia, due to superior facility of application in natural forests. The developed equations showed to be good representations of the degree of competition at the level of the individual tree of A. angustifolia for the two evaluated sites, measuring only the diameter or including the height of the objective tree for more accurate precision. The expansion of research to other sites along the distribution of the species will confirm the application of these equations to their full extent. In addition, this work contributes to the inclusion of competition indices in modeling of individual trees in uneven-aged mixed forests. [ABSTRACT FROM AUTHOR]

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to develop the density management diagram of Araucaria Uneven Aged Forest, located in Lages city, SC. Plots with predominance of Araucaria angustifolia (Bertol.) Kuntze trees growing under high competition were sampled in order to determine the basal area per hectare, the number of trees per hectare, mean basal area diameter, volume per hectare, dominant height and average height, applying the point density method proposed by Spurr (1962). The Reineke (1933) model was adjusted and had recalculated the intercept value to set the maximum density line. The average trading volume in the sample point was estimated with adjustment of Schumacher and Hall (1933) model modified. All models were evaluated for their adjustment statistics, accuracy and graphical analysis of residuals. Slope coefficient of the Reineke (1933) model was -1.5192, confirming the Law of -3/2 power of self-thinning. Management dendrograms developed for basal area, commercial volume in function of the number of trees per hectare and average diameter of basal area, can assist in forest operations, optimizing production according to the condition of the site and growth characteristics of the species. [ABSTRACT FROM AUTHOR]