Allometric equations for estimating the aboveground biomass of bamboos in northern Laos

Bamboos are dominant plants in northern Laos, where they are closely associated with local people's livelihoods. We developed species-specific allometric equations for estimating aboveground biomass from culm size parameters (diameter at breast height [DBH] and (DBHH)-H-2; H is a culm length) using 11 common bamboo species in the region. The applicability of multi-species allometric equations based on pooled data was also examined. Most species-specific allometric regressions showed significant correlations. In addition, the multi-species allometric relationships for culm biomass and aboveground biomass showed particularly high correlations (r(2) > 0.96), indicating the usefulness of multi-species allometric equations to estimate bamboo biomass in mixed-species bamboo forests with unknown bamboos and bamboos without species-specific allometric equations. The generally small differences in the fitness of aboveground biomass estimates between DBH and (DBHH)-H-2 indicate that DBH is a practical explanatory variable for biomass estimation. These species-specific and multi-species allometric equations will help in developing future work on carbon stocks and cycles in bamboo forests in this region.