Total Volume and Aboveground Biomass Models for &amp;lt;i&amp;gt;Juniperus procera&amp;lt;/i&amp;gt; Plantation in Wondo Genet, Southern Ethiopia

Tekleweini Gereslassie,Muhamed Adem,Leakemariam Berhe,Ababo Workineh,Goitom Takele

doi:10.4236/ojf.2019.92004

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 (R2), bias (B) and mean of the absolute value of errors (MAE). Accordingly, the total volume model Vt = -5.466 + 0.959Dbh0.005H003 and aboveground biomass model of B = 0.348Dbh0.57H0.032 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/m3. 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.

Highlights

Forests play a significant role in sustaining economy, ecology and social development and growth (Chakravarty et al, 2011)
This study was basically focused on fitting total volume and aboveground biomass models for Juniperus procera plantations in Wondo Genet, Sidama Zone, Ethiopia
The results revealed that considering diameter at breast height (Dbh) has a greater effect on prediction of total tree volume, considering the variability of Dbh in fitting volume models is crucial

Summary

Introduction

Forests play a significant role in sustaining economy, ecology and social development and growth (Chakravarty et al, 2011). Direct measurement of volume and biomass in most cases gives a reasonable accuracy, employing field measurement especially in large-scale plantation projects is quite expensive, labour-intensive, mostly destructive, time-consuming and sometimes impracticable (Li & Xiao, 2007; Ounban et al, 2016). Estimation of volume and biomass using allometric equations which can represent the field measurement for large-scale industrial plantations is highly advisable (Lehtonen et al, 2004; Zianis et al, 2005; Oyamakin, 2011). Forest growth models have the ability of describing the development of tree crops with specific time changes, species and sites (Hjelm, 2015). There are various types of forest models including tapper model, crown models, total tree volume and biomass models are the commonly applied models in forest management planning, estimating the forest volume, tree biomass, carbon content and evaluating the ecological roles forests (Akindele & LeMay, 2006; Berhe, 2009)

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Discussion

Conclusion