Allometric equations for accurate estimation of above-ground biomass in logged-over tropical rainforests in Sarawak, Malaysia

Abstract

Although allometric equations can be used to accurately estimate biomass and/or carbon stock in forest ecosystems, few have been developed for logged-over tropical rainforests in Southeast Asia. We developed allometric relationships between tree size variables (stem diameter at breast height (dbh) and tree height) and leaf, branch, stem and total above-ground biomass in two logged-over tropical rainforests with different soil conditions in Sarawak, Malaysia. The study sites were originally classified as mainly lowland dipterocarp forest and have been selectively logged in the past 20 years. In total, 30 individuals from 27 species were harvested to measure above-ground parts. The correlation coefficients for the allometric relationships obtained for total above-ground biomass as a function of dbh had high values (0.99), although the relationships for leaf biomass had a relatively low coefficient (0.83). We also found relatively high coefficients for allometric relationships between tree height and plant-part biomass, ranging from 0.82 to 0.97. Moreover, there were no differences for allometric equations of total above-ground biomass between study sites. A comparison of equations of above-ground biomass in various previously reported tropical rainforests and pan-tropic general equations imply that our allometric equations differ largely from the equations for tropical primary forests, early successional secondary forest, and even for the general models. Therefore, choosing the biomass estimation models for above-ground biomass in the logged-over forests of Southeast Asia requires careful consideration of their suitability.

Mapping Forest Ecosystem Biomass Density for Xiangjiang River Basin by Combining Plot and Remote Sensing Data and Comparing Spatial Extrapolation Methods

“…Applying the allometric equations to other study areas will cause uncertainties of forest ecosystem AGB estimates [11,[93][94][95]. In this study, several allometric equations were used to estimate the values of AGB of trees by species; however, the uncertainty from the used allometric equations was unknown.…”

Allometric Equations for Estimating Carbon Stocks in Natural Forest in New Zealand

“…It is clear that both equations provided reasonable predictions of above ground biomass carbon across a range of groups of species and tree size classes. Various other researchers have compared allometric equations they developed for estimating above-ground biomass in tropical forest [30,31] with the pan-tropical equations developed by Chave et al [9], and concluded that general allometric equations were biased when applied at their sites. This was surprising to us, considering the results of the comparisons we made.…”

Carbon Stocking in the Natural Forests – The Case of Malaysia

“…Basuki et al (2009) described that the establishment of allometric equations is related to the biophysical properties of trees, namely diameter at breast height (DBH), wood density and height. Several researchers formulated equations for the determination of biomass (Kato et al, 1978;Chambers et al, 2001;Chave et al, 2005;Kenzo et al, 2009;Blujdea et al, 2012,). Researchers such as Hamdan et al (2011);Hamdan et al (2014); Morel et al (2011);Saner et al (2012); Sato et al (2013) applied the established equations to calculate the forest biomass.…”