Allometric equations for estimating the above-ground biomass of Castanopsis indica at juvenile stage

Abstract

Most of the Castanopsis indica forest of Nepal in the midhill region was degraded in the recent past especially due to policy conflict between government and local users. But after the introduction of community forestry system, these forests have been rejuvenated gradually. Therefore, the proportion of the juvenile plants in forests is very high and the contribution of juvenile plants on total biomass production cannot be overlooked. Therefore this study was carried out to develop juvenile biomass models. We measured diameter at 10 cm above ground level (D), total height (H), density (ρ) and total biomass (W) of indica juveniles. The models were estimated using "library (minpack.lm)" in R. The estimated models were evaluated by using numerical fit statistics and graphical analyses. The selected model Ŵi = 52.28 (D i 2 H i ) 0.89 explained >95% juvenile biomass of indica with RSE=42.34g, AIC=406.8 and average deviation=13.26.

A GENERALIZED ABOVEGROUND BIOMASS MODEL FOR JUVENILE INDIVIDUALS OF Rhododendron arboreum (SM.) IN NEPAL

“…It may not be relevant to compare any biomass model developed for different species, components, and locations, as several factors may determine the accuracy of the model. However, our biomass models are closely comparable to those developed aiming at predicting aboveground biomass of the juvenile individuals of three tropical species (Shorea robusta, Terminalia tomentosa, and Acacia catechu) (Chapagain et al, 2014) and two sub-tropical species, such as Castanopsis indica (BhandarI and Neupane, 2014a) and Alnus nepalensis (Bhandari and Neupane, 2014b), and dry-tropical species (ChaturvedI et al, 2012a, b). Our models are slightly inferior to those developed by Chapagain et al (2014) but superior to those of Bhandari and Neupane (2014a, b).…”

“…In the past, priority was given to develop the allometric biomass equations only for larger-sized trees which could be used for timber (Navar, 2009b;Muukonen, 2007;Muukkonen and Makiapa, 2006;Zianis et al, 2005;Brown et al, 1989). However, in recent years, some studies (Chapagain et al, 2014;Chaturvedi et al, 2012a;Bhandari and Neupane, 2014a;2014b) were carried out to develop allometric biomass equations for smaller-sized plant individuals, such as juveniles (plant ≥30 cm in height and <10 cm in circumference at 10 cm aboveground surface) (Chaturvedi et al, 2012a). It is necessary do so, because of the importance of the juvenile plants, which have a significant contributions to future forest, soil conservation, and wildlife habitat (Modrzynski et al, 2015).…”

“…Main reason for this exclusion is due to unavailability of allometric biomass equations for R. arboreum juveniles. Allometric equations to estimate the biomass of juvenile stage plants in Nepal have been developed for Shorea robusta, Terminalia tomentosa, Acacia catechu (Chapagain et al, 2014), Castanopsis indica (Bhandari and Neupane, 2014a), Alnus nepalensis (Bhandari and Neupane, 2014b). The existing juvenile biomass models are applicable to tropical forest (Chapagain et al, 2014) and sub-tropical forest (Bhandari and Neupane, 2014a;2014b).…”

“…Allometric equations to estimate the biomass of juvenile stage plants in Nepal have been developed for Shorea robusta, Terminalia tomentosa, Acacia catechu (Chapagain et al, 2014), Castanopsis indica (Bhandari and Neupane, 2014a), Alnus nepalensis (Bhandari and Neupane, 2014b). The existing juvenile biomass models are applicable to tropical forest (Chapagain et al, 2014) and sub-tropical forest (Bhandari and Neupane, 2014a;2014b). To the authors' knowledge, none of the allometric biomass models for juvenile plants has been developed for R. arboreum so far.…”

Allometric Aboveground Biomass Models for Northern Delhi Ridge Forest

“…Earlier, priority was given to large -sized timber trees for development of allometric biomass models [13,14,15]. Recently, some studies have also come up discussing allometric biomass models for juvenile plants as well [16,17,18,19]. Gathering aboveground biomass data for juvenile plants is essential as they significantly add to future forest, wildlife habitat and soil conservation [20].…”