Allometric scaling, biomass accumulation and carbon stocks in different aged stands of thin-walled bamboos Schizostachyum dullooa, Pseudostachyum polymorphum and Melocanna baccifera

Abstract

In recent decades, bamboos have become globally important biomass resources in tropical regions. However, bamboo stands have uneven age structure, and often differently aged culms are found distributed throughout a stand. This makes estimation of their biomass and carbon stocks more complicated than forest trees. Therefore, the present study was undertaken to: (i) determine whether or not growth and biomass accumulation in thin-walled bamboos follow simple height-diameter (H-D) relationships and allometric scaling rules, and (ii) develop models for estimation of biomass and carbon stocks in different aged stands of the bamboos Schizostachyum dullooa, Pseudostachyum polymorphum and Melocanna baccifera in North East India. The H-D relationships and allometric scaling between above-ground biomass (AGB), culm height (H) and diameter at breast height (D) were examined using various models. The results demonstrate that H, D and AGB are allometrically related in the different aged bamboo stands. However, these relationships significantly deviated from theoretical predictions. The common functions used for modelling H-D relationships also gave significantly differing estimates of the asymptotic height (Hmax) highlighting large uncertainty in the choice of H-D functions. Our findings indicate that use of volume provides better biomass prediction in the three species than either D or H alone. Aboveground biomass carbon densities of the bamboo forests were estimated at 23Mgha–1 for S. dullooa, 21Mgha–1 for P. polymorphum and 58Mgha–1 for M. baccifera forests. The estimated carbon density of M. baccifera was comparable with values reported for thick walled bamboos in North East India and elsewhere. Although S. dullooa and P. polymorphum had lower carbon densities, the ability of these species to grow fast after forest disturbance indicates their potential for abating land degradation and carbon management by preventing losses from forest degradation. These species also hold great potential for biomass production given the local tradition of planting them in home gardens.