Compatible System for Predicting Total and Merchantable Stem Volume over and under Bark, Branch Volume and Whole-Tree Volume of Pine Species

Abstract

Accurate quantification of branch volume in trees is important for sustainable forest management, especially as these fractions are increasingly used for bioenergy, and for precise forest CO 2 quantification. Whereas a large focus has been placed on the compatible estimation of tree taper and bole volume with and without bark, little effort has been made to develop models that allow a simultaneous prediction of these variables together with tree branch volume. In this study, 595 Pinus cooperi trees and 700 Pinus durangensis trees were sampled in pine-oak forests in the Sierra Madre Occidental, Mexico. A compatible system for predicting two segmented taper functions, over and under bark; the corresponding merchantable volumes; coarse branch volume and whole-tree volume was fitted using a modified continuous autoregressive structure to account for autocorrelation. The proposed compatible equations explained more than 97% of the observed variability in diameter over and under bark, volume over and under bark, and total tree volume and more than 64% of the observed variability in branch volume in both species. The method described can theoretically be replicated for any tree species, thus providing a better understanding of the patterns of volume distribution by components, potentially improving carbon accounting system and forest bioenergy planning.

Taper and Volume Systems Based on Ratio Equations for Pinus pseudostrobus Lindl. in Mexico

“…Vb obtained as the subtraction between Vt and Vs allowed a lower number of parameters within the system. This equation has a simple mathematical structure and showed reliable statistics, which were similar to those reported by Corral-Rivas, Vega-Nieva, Rodríguez-Soalleiro, López-Sánchez, Wehenkel, Vargas-Larreta, Álvarez-González and Ruiz-González [12] for a compatible system of Pinus in Durango, Mexico, where they calculated Vb directly in function of diameter at breast height and crown radius.…”

“…This would allow better understanding of the relationships and exchanges among different types of forest ecosystem services, such as carbon sequestration against timber production [12,13]. The equations of d, Vm, Vs, Vt and Vb can be estimated simultaneously with compatible systems based on volume ratio equations.…”

Stem Taper Estimations With Artificial Neural Networks for Mixed Oriental Beech and Kazdaği Fir Stands in Karabük Region, Turkey

“…The development of the stem taper equations began in the late 1960s, and they have been still widely used today in forestry literature (e.g., Bruce et al, 1968;Kozak et al, 1969;Hjelm, 2013;Arias-Rodil et al, 2015;Corral-Rivas et al, 2017). Various types of stem taper equations have been published, and these equations are basically classified according to their model forms such as (i) simple polynomial (e.g., Bruce et al, 1968), (ii) segmented (e.g., Max and Burkhart, 1976;Clark et al, 1991;Fang et al, 2000), and (iii) variable-exponent (e.g., Bi, 2000;Kozak, 2004) taper equations (Diéguez-Aranda et al, 2006;Sakici et al, 2008).…”

“…Since the initial studies on stem taper estimations, the regression analysis approach has been commonly utilized (e.g., Kozak et al, 1969;Max and Burkhart, 1976;Clark et al, 1991;Kozak, 2004;Özçelik and Brooks, 2012;Corral Rivas et al, 2017). However, the knowledge on the use of ANN techniques for stem taper estimation is quite limited (e.g., Diamantopoulou, 2010;Özçelik et al, 2010;Leite et al, 2011;Özçelik et al, 2014;Nunes and Görgens, 2016), although this approach has been widely used in some other research areas of forestry (e.g., Diamantopoulou et al, 2009;Diamantopoulou and Millios, 2010;Cai et al, 2012;Diamantopoulou and Özçelik, 2012;Ashraf et al, 2013;Castro et al, 2013;Özçelik et al, 2013;Yurtseven et al, 2013;Ashraf et al, 2015;Diamantopoulou et al, 2015;Vahedi, 2016;Nazerian et al, 2018).…”

“…equation,Diéguez-Aranda et al (2006),,Özçelik et al (2016) andCorral-Rivas et al (2017) forFang et al (2000) equation,Li and Weiskittel (2010) andde- Miguel et al (2012) forBi (2000) equation, and Fonweban et al (2011) andMenéndez-Miguélez et al (2014) forKozak (2004) equation). The stem taper equations were fitted using model development data by MODEL procedure of SAS software for both species.…”