TITLE:
Using Biophysical Variables and Stand Density to Estimate Growth and Yield of Pinus patula in Antioquia, Colombia
AUTHORS:
Héctor I. Restrepo, Sergio A. Orrego, Juan C. Salazar-Uribe, Bronson P. Bullock, Cristian R. Montes
KEYWORDS:
Von Bertalanffy, Chapman-Richards, Fixed-Effect Models, Forest Productivity, Mexican Pine, Mean Annual Increment
JOURNAL NAME:
Open Journal of Forestry,
Vol.9 No.3,
June
24,
2019
ABSTRACT: Timberland investment
opportunities in Colombia are expected to increase as a result of the peace
agreement recently signed between the Colombian government and the Revolutionary Armed Forces of Colombia. This new socio-political
environment may facilitate the expansion of commercial forest plantations on a
wider range of site conditions that are currently considered in existing
biometric tools. Data from 1119 temporary plots of unthinned, unmanaged, and
genetically unimproved Pinus patula plantations in the Antioquia region were combined with a large set of
biophysical attributes to identify spatial variation in yield. A wide array of biophysical covariates was
explored to characterize the most favorable environmental conditions for the
species, and to identify potential explanatory variables to be included in
forest yield models. The mathematical form of the model is the von
Bertalanffy-Chapman-Richards type, with parameters: asymptote, intrinsic growth
rate and allometric constant. The parameters were
expressed as linear functions of soil pH,
terrain slope, the mean annual temperature to mean annual precipitation ratio,
and stand density. The statistical contribution of selected covariates was evaluated using the likelihood ratio test. The model was validated using an independent set of
133 observations. The spatial representation of the model depicts the timber
production potential and allows for the identification of the most suitable
geographical areas to establish Pinus
patula plantations in Antioquia, Colombia. The estimated yield model
provides a reliable baseline for timber production, and insight into timberland
investments in Colombia.