Abstract

BAVA, J. O.  and  LOPEZ BERNAL, P. M.. Prediction of Diameter at the breast height from stump dimensions of lenga (Nothofagus pumilio) trees in Tierra del Fuego, Argentina. Quebracho (Santiago del Estero) [online]. 2006, n.13, pp.87-92. ISSN 0328-0543.

The lenga state forests of Tierra del Fuego, Argentina, historically have sustained most of the province forest industries. These forests generally were used without appropriate silvicultural criteria and with a harvesting rate that possibly will finish the fiscal reserves of old growth productive forest in the short term. In order to avoid this situation towards a sustainable management, it's necessary to reduce the annual rate of harvesting, to implement silvicultural criteria, to perform a stronger State control and to evaluate the incorporation of harvested areas that have recovered their productivity, defining specific management criteria for these forests. For this last point it's necessary to know the initial characteristics of the stands and the harvesting characteristics. In order to construct a tool that offers basic information for specific decision making at stand level, data of 973 trees (d, dh, h) were collected, distributed in 60 sites throughout the Fagnano lake basin. Predicting models of d, based on the other two variables, were adjusted using the stepwise method. Given the found heterocedasticity, the procedure was repeated with logaritmized variables. Model (R²= 0,971; EEE = 0,0324) was choose. This tool will be useful both to determine the original structure of the forest and to find out the harvesting characteristics. The use of variables such us stump diameter and height, and stand related variables such us site quality and structure is discussed.

Keywords : Harvested forest; Regression; Structure.