Allometric Equations to Estimate Dry Biomass of <i>Vachellia tortilis</i> in Indira Gandhi Nahar Pariyojna area of Rajasthan

Abstract

A massive plantation forests have been established in arid region of north western India for environmental, economic and livelihood benefits to the local people. However, their contribution to climate change mitigation is poorly understood, because of lack of allometric equations for biomass estimation. Objective of this study was to develop species-specific allometric models for estimating total, stem, branch, and leaf biomasses of Vachellia tortilis planted in western Rajasthan. Different linear and non-linear models were fitted to establish relationship between dry biomasses of different components of above-ground part of V. tortilis trees with diameter at breast height (DBH) and total height (H) and allometric equations were selected based on model performance statistics. Trees were 6.0-15.6 m tall, 10.50-54.10 cm in diameter, 19.0-773 kg tree -1 stem biomass, 28.0-2166 kg tree -1 branch biomass, 1.0-51.0 kg tree -1 leaf biomass and 58.0-2848 kg tree -1 total biomass. Model Y= a Exp bDBH was best fit with DBH and fulfilled the validation criterions with highest R 2 and lowest residual error (σ), Akaike information criteria and root mean square error values. The value of adjusted R 2 was >0.90 for the equations fitted on biomasses of different components except leaf biomass (adj. R 2 = 0.46). Statistical variables of all components were highly significant (p<0.01) indicating the accuracy and precision of the equations. The developed biomass regression models can be applied as a species-specific equation in predicting standing biomass and carbon sequestration benefits of V. tortilis in north western India.