Generalized height-diameter models for five pine species at Southern Mexico

Abstract

Generalized height-diameter at breast height (D) models are essential for the estimation of the timber stocks of a forest stand, as well as in the generation of base information to develop forest growth models, and as basic inputs in the development of forest management plans. Generalized models were developed to estimate total height (TH) based on the D and stand variables, of five Pinus species in forests under forest management of Ixtl an de Ju arez, Oaxaca, Mexico. The data used come from a timber forest inventory, where n ¼ 1041 sampling plots of 1000 m 2 each were established based on a stratified-systematic sampling design. The species selected according to their relative abundance were: Pinus patula, Pinus oaxacana, Pinus ayacahuite, Pinus teocote and Pinus leiophylla. Five nonlinear equations were fitted using regression techniques to predict the TH of the trees under several silviculture regimes and forest management conditions. The statistical criteria of goodness of fit used were: adjusted coefficient of determination (R 2 adj ), root mean square error (RMSE) and absolute average bias in the prediction ( E). Likewise, the graphic analysis of the predictive capacity of the equations was considered. The D and the stand variables (quadratic mean diameter, dominant diameter and dominant height) for these species explained between 75 and 83% of the variability of the TH data. The predicting variables to apply the developed generalized models to estimate tree's total height require less sampling effort and are derived from conventional forest inventory data, which allows to reduce costs and time in field work.

Height-Diameter Relationship of Some Forest Species Exploited for Wood in the Natural Tropical Forest of the Congo Basin

“…Both in forest-savanna transition zones and in dense semi-deciduous humid forest areas, the height-diameter relationship follows a linear model for all the 8 (eight) species studied. These results corroborate those of various authors who have worked on the height-diameter relationship either in monospecific, monostrate forest plantations (Fortin et al, 2009;Sharma & Zhang, 2004;Robinson & Wykoff, 2011;Huang et al, 1992;Sharma & Parton, 2007;Trincado et al, 2007;Kebede & Soromessa, 2018;Santiago-García et al, 2020;Baumeister, 2017;Sharma & Breidenbach, 2015) or in multi-stratum and multi-species natural forest (Mugasha et al, 2013;Temesgen et al, 2014;Tsega et al, 2018). However, the determination coefficient is high (R 2 > 0.6) in the forest-savanna transition zone and low (R 2 > 0.5) in the dense humid semideciduous forest, but the probability associated with the Fisher test for the 8 (eight) species in both sites is less than 0.0001 and therefore highly significant.…”

Comparative Analysis of Three Forest Management Plans in Southern Mexico

“…The study was conducted in the communal forest under management of the community of Ixtlán de Juárez, Oaxaca, Mexico (Figure 1), located within the geographic coordinates 17°18′16″-17°30′00″ N and 96°21′29″-96°31′38″ W, ranging in altitude from 2200 m to 3100 m. Most of the pine-oak forest land area has a humid temperate climate with summer rains, and the pine and oak species are mainly harvested species groups [18,30]. In the analytical comparison of the Ixtlán de Juárez community FMPs, data from three forest inventories of forest management planning were used.…”

“…Species dominance depends on the silvicultural treatment applied, in addition to the characteristics of the species in responding to natural regeneration and the conditions of the forest site. In the study area, even when different treatments were applied or a combination of the single-tree selection method with the strip clearcutting method was applied in the same sub-stand, the dominant species changed often or, in several cases, remained stable, as in the case of Pinus patula, because its relative abundance was higher [30]. This is also attributed to the fact that artificial regeneration was carried out in the community, and this was one of the main species produced in the nursery, because of its morphological characteristics and broad adaptation capacity [31,41].…”

Índice de sitio para plantaciones forestales de Pinus patula en el Estado de México

“…La clasificación de la productividad de áreas arboladas con base en la altura dominante (Ad) es esencial para la gestión de rodales forestales de acuerdo con las diversas condiciones ambientales que influyen en el crecimiento, ya que permite identificar zonas óptimas para el establecimiento de plantaciones forestales (PF) (Torres y Magaña, 2001;Martínez-Zurimendi et al, 2015;Scolforo et al, 2016;Santiago-García et al, 2020).…”