Development of site index functions for Eucalyptus grandis grown in the argentine Mesopotamia

Received: January 21st, 2011 // Accepted: August 26th, 2011// Published: online September 21st, 2011

CRECHI, E.H.1; FASSOLA, H.E.1; KELLER, A.E.1; BARTH, S.R.1

Abstract
Equations for the prediction of site index (SI) of Eucalyptus grandis planted in the Mesopotamia region of Argentina were developed. The estimation was made through the assessment of a data base including 106 plots (439 pairs of age – dominant height, age-Hdom). 48 (197 pairs age-Hdom) plots were located in the area between the province of Misiones and NE region of the province of Corrientes. Another 58 plots (242 pairs age-Hdom) were located in the Concordia-Monte Caseros region (SE of the province of Corrientes – NE of the province of Entre Ríos). When the evolution of the relationship between age-Hdom of both areas was analyzed, it was possible to determine that slopes of the models in each area were different, and therefore site functions for each area were fitted. Three traditional methods to fit site index curves were used: the guide curve method, the parametrized prediction method and the algebraic difference approach (ADA). Quality of the available information in the studied region was the parameter influencing the election of the method used to fit the slope, although certain criteria were prioritized such as polymorphism, base-age invariant and stability of the model against its data base. The guide curve method was applied in the Misiones-NE Corrientes region with
good results, whereas a site index function based on Schumacher model fitted with the algebraic difference approach (ADA) method was chosen for the Concordia-Monte Caseros region.
Keywords: site index, algebraic difference approach, forest management,Eucalyptus grandis, Argentina.