Modelos de crecimiento diamétrico para Nothofagus dombeyi = Diameter growth models for Nothofagus dombeyi

Abstract

Se desarrollaron varios modelos de crecimiento diamétrico para la especie Nothofagus dombeyi. La función seleccionada para el estudio es no lineal, usualmente denominada Bertalanffy-Richards. La misma se ajustó a partir de tres fuentes de datos: parcelas permanentes, análisis fustales y tarugos de incremento. Estos datos fueron segregados por estrato social y luego para cada uno se ajustó la citada función con las variables incremento diamétrico (id)- diámetro a la altura del pecho (dap). Los ajustes y análisis se realizaron a partir de dos grupos de datos. Por un lado se utilizaron datos independientes que provenían principalmente de las parcelas permanentes, mientras que por otro se emplearon series temporales dadas por los tarugos y los análisis fustales. Con ambos grupos se obtuvieron modelos con aplicaciones diferentes. Con el grupo de datos independientes se obtuvieron modelos de interés para la predicción del incremento diamétrico en el corto plazo, mientras que con las series de crecimiento se lograron modelos de una alta significancia biológica. A través de estos modelos biológicos se interpretó la dinámica de crecimiento de las especies estudiadas bajo diferentes situaciones de competencia.

Models of diameter growth for Nothofagus dombeyi were developed and the selected model used for this study was non-linear and known as Bertalanffy-Richards. It was fitted from three main data sources: permanent plots (with only two measurements each), stem analysis and tree cores. The data was divided into social strata and then, for each stratum, the model was fitted according to the variables: diameter annual increment (id) and diameter at breast height (dap). The fitting, and both biological and statistical analysis, was carried out taking two different data sets into account: an independent data set, provided by permanent sample plots; and a growth series, provided by tree increment cores and stem analysis. Models with different uses were obtained through both data sets. With the independent data, we obtained models that allowed us to predict the diameter annual increment in a short time and, with the growth series, we obtained models of a high biological significance. In this sense, the biological significance of the parameters from each model was discussed when they were fitted. An interpretation of the dynamic growth of the species studied has been undertaken through the biological models under different competence status.