Effects of Stand Age Classes on Biomass Expansion Factors and Stem Densities in Chamaecyparis obtusa Plantations

摘要

Biomass expansion factors and stem density values were commonly used in converting stand volumes into total carbon stocks for the purpose of national inventories of greenhouse gas emissions and carbon sequestration. The objective of this study was toexamine the influence of stand age classes on aboveground and total biomass expansion factors, and stem density values in Chamaecyparis obtusa species. A total of 25 representative sample trees based on the three different stand age classes were destructively sampled to measure green weights and dry weights of the major four(root, stem, branch and foliage) portions of C. obtusa species grown in Jangseung-gun of southern Korea. According to the results of this study, as stand age classes increase, totalbiomass expansion factors tended to be decreased with the ranges from 3.64 to 1.44, while the stem density values tended to be slightly increased with the ranges from 0.35(g/cm~3) to 0.44(g/cm~3). There were statistically significant differences in biomass expansion factors and stem density values between stand age classes, but became nearly constant after 30 years old for C. obtusa species. This information could be very useful to improve a national-scaled inventory of greenhouse gas emissions and carbon sequestration for the C. obtusa species by applying different biomass expansion factors and stem density values.