DYNAMIC EQUATIONS OF GROWTH IN DOMINANT HEIGHT AND SITE INDEX FOR Pinus patula SCHIEDE ex SCHLTDL. & CHAM.

Abstract

The application of intensive silviculture in sustainable forest management requires efficient quantitative tools to adequately estimate growth patterns of trees and stands. The development of scientifically-based mathematical models represents a vital input for making projections of growth and yield over time for commercial forest species. The aim of this study was to fit dynamic equations of algebraic difference (ADA) and generalized algebraic difference (GADA) approaches for growth in dominant height and site index in Pinus patula Schiede ex Schltdl. & Cham. growing in even-aged stands at Ixtlán de Juárez, Oaxaca. The data used came from 66 permanent sampling sites established in 2015 and re-measured in 2016 and 2017. The equations were fitted using the nested iterative procedure, which is a base-age-invariant technique. The statistical indicators of goodness-of-fit, graphical analyses and predictive capacity of the models suggest that the best equation to model the dominant height growth was the GADA formulation derived from the Bertalanffy-Richards model. The average dominant height at the base age of 40 years was 29 m. The GADA-type model will allow to adequately estimate the productivity of P. patula stands. The approaches used to model the dominant height growth are efficient techniques to develop biometric tools to support decision-making in forest management to predict current and future production.