Total Volume and Aboveground Biomass Models for <i>Juniperus procera</i> Plantation in Wondo Genet, Southern Ethiopia

Abstract

Species specific allometric equations are important for estimation and quantification of net volume and aboveground biomass of living trees. This study was basically focused on fitting total volume and aboveground biomass models for Juniperus procera plantations in Wondo Genet, Sidama Zone, Ethiopia. Data for fitting the total volume and aboveground biomass models were obtained by destructively sampling of trees from the ten diameter classes of the Juniperus procera plantation in the study area. A total of one hundred ten and fifty-one trees were destructively sampled to fit six total volume and six aboveground biomass models respectively. After important measurements of parameters have completed, model performance evaluation and selecting of best fit models were undertaken using standard error of estimates (SEE), coefficient of determination (R 2), bias (B) and mean of the absolute value of errors (MAE). Accordingly, the total volume model Vt = −5.466 + 0.959Dbh 0.005 H 003 and aboveground biomass model of B = 0.348Dbh 0.57 H 0.032 were found to be the best predictive models for total tree volume and aboveground biomass respectively. In addition to the above results, diameter at breast height and total tree height data obtained from 69 circular sample plots of 0.01 ha area drawn from the plantation were used to estimate the total volume and aboveground biomass per hectare BEF which was estimated to be 0.64 Mg/m 3. Generally, the selected models and computed BEF in this study are believed to be applied by different organisations and researches to estimate the total volume and aboveground biomass of the J. procera.

Aboveground Biomass Models for Indigenous Tree Species in the Dry Afromontane Forest, Central Ethiopia

“…To determine the dry matter contents of the sampled trees, representative subsamples of the three components were taken to the laboratory for dry weight determination. In the laboratory, foliage samples were dried at 70 °C, whereas woody parts or collected discs and branches were dried at a temperature of 105 °C for all sample categories until a constant weight is reached, as used in [48,49]. Te weight of each dried disc, branch, and piece of foliage was measured using a beam balance weighing 100 kg.…”

Mixed-Species Allometric Equations to Quantify Stem Volume and Tree Biomass in Dry Afromontane Forest of Ethiopia

“…We selected the equations from the forestry literature based on their widespread use in Ethiopia and elsewhere (Berhe, 2009;Burkhart & Tomé, 2012;Picard et al, 2012;Mugasha et al, 2013;Gereslassie et al, 2019).…”

“…Such information is gaining both economic and political currency in renewable energy development, carbon credit markets, and REDD + projects (Nath et al, 2019). Very few species-specific volume models (Pohjonen, 1991;Teshome, 2005;Berhe et al, 2013;Gereslassie et al, 2019;Tsega et al, 2019;Takenaka et al, 2020) and mixed and species-specific biomass models (Tesfaye et al, 2016;Solomon et al, 2017;Feyisa et al, 2018;Mokria et al, 2018;Abich et al, 2019;Daba & Soromessa, 2019;Tetemke et al, 2019) are available in Ethiopia. These models are developed either for single tree species or mixed species by using a very small number of trees and/or the sampling does not include the larger diameter size trees in the forest.…”

Development of Stem Volume Equation for Urban Trees of Abomey-Calavi in Southern Benin (West Africa)

“…The volume of bottom section was obtained using the formula for truncated Neloid [37], and then Smalian's formula was used to compute the volume to the following section (0.3-1.3 m height) of the tree. For the top stem section (up to 1.3 m height), truncated cone formula was used to calculate its volume [16,25]. The volume of the different sections were summed up to calculate the stem volume [38,39].…”

“…Recent research works use allometric equations constructed from easily measurable tree parameters (diameter, height and forms) to estimate individual tree and stand volume [12,15,16]. Thus, generalized allometric models are fitted for multiple species in tropical forests, and they are usually employed to evaluate timber volume in various countries [17,18].…”