Carbon and Nitrogen Accumulation and Distribution in Taiwania Plantions of the Liukuei Experimental Forest t-Litter layer and forest soils

Two Taiwania plantations aged 20 and 27 yr in the Liukuei Experimental Forest were selected in order to estimate the biomass, carbon, and nitrogen accumulation and distribution. According to the allometric equation established by data from 28 harvested sample trees, the biomass of each component and the total biomass of trees were highly significantly related to the diameter at breast height (dbh). The estimated Taiwania biomass values were 204 and 254 ton ha-1 for the 20- and 27-yr-old stands, respectively, which were higher than values of the thinned stand at the same ages. The major biomass of the stand was in Taiwania. Carbon and nitrogen of the stand accumulated primarily in the soil, comprising 46-59% and 83-88% of the total amount, respectively. In soil the majority of the carbon and nitrogen was stored in the first 0-15-cm of depth. The average conversion coefficient from timber volume to biomass was 0.42 (Mg m-3), while the average conversion coefficient from timber volume to aboveground carbon storage was 0.22 (Mg m-3).