Combining diameter-distribution function with allometric equation in biomass estimates: a case study of Phyllostachys edulis forests in South Anhui, China

摘要

Large-scale biomass estimates are primarily based on the estimation of biomass at the stand level. The accurate estimation of forest biomass at the stand level is vital for regional carbon budgets, estimates of the global carbon cycle, and reports on stock changes required by the Kyoto Protocol. However, currently available stand-level methods do not account for variations in biomass within a stand and are unable to fully reflect developments and changes in stand structures. Here, we identified the best diameter-distribution function among six common distribution functions (normal, lognormal, exponential, gamma, logistic, and Weibull) using Akaike's information criterion and then developed a diameter-distribution model that combines the selected diameter-distribution function with an allometric equation to estimate the biomass of Moso bamboo forests in South Anhui Province, China. We found that a three-parameter Weibull distribution best characterized the diameter distribution of the Moso bamboo stands. The biomass derived from the allometric equation was small compared to the biomass estimated using the Weibull distribution model (52.39 vs. 53.25 t/ha), suggesting that bamboo forest biomass and carbon stocks determined at various levels using the common allometric equation alone have been underestimated. The use of a diameter-distribution model to estimate bamboo forest biomass and carbon stock is expected to improve the estimation accuracy.