| This article used method of tiered rating investigation in platycladus orientalis plantation,analysis distribution of platycladus orientalis plantation up-ground parts and roots organiccarbon content at Qianyang area in loess plateau, and contrast soil organic carbon density andtotal organic carbon density in wasteland and different ages of plantation, concluded that:1)Organic carbon is more concentrated in trunk, taproot,provided that for the evergreen treespecies have less litter, supplement of organic carbon to soil carbon library is less.Butretention rate of organic carbon is relatively high. As for shrub layer and herb layer,with theincreased competitive, organic carbon density is reduced.As arborvitae tree part is the mainbody of ecological system and can be added litter by increasing the total carbon library,arborvitae plantation ecosystem of the part with the increasement of arborvitae plantation age,present a growth trend.2) Different artificial forests soil have the same apparent verticaldistribution features of0to10cm and10to20cm of soil layer while the rest of the layers ofsoil organic carbon density had significant difference (P <0.05). Below30cm the soilorganic carbon density difference is not significant. The biota orientalis root organic carboncontent and soil organic carbon density distribution trend have the same change trend, knownbiota orientalis root system on soil organic carbon library supplement is bigger.3) Duringearly afforestation, the impact on soil organic carbon density is small, but with theincreasement of fixed number of year, soil organic carbon density increased.The ecosystemhas significantly increased total organic carbon. Turning farmland to forest has importantecological significance, greatly improved the soil and ecosystem, and total organic carbonsequestration born35years using ecosystem twice of the wasteland, total organic carboncontent of soil organic carbon density increased by23.55%.4) With the increasement offorest age, total organic carbon density and the ecological system of soil organic carbondensity rise.Tree layer as the principal part of ecological system greatly influences the totalorganic carbon density change trend, and along with the increase of forest age, the impact onthe ecological system of the total organic carbon increased, the rest of the componentsthrough the interaction, improve the density of total organic carbon.5) Arborvitae ecosystemtotal organic carbon and organic carbon density of each part size analysis.The effect to the total ecosystem of organic carbon for plantation age, arbor layer and soil layer, the ecologicalsystem, the direct contribution of total organic carbon content and the largest indirectcontribution to soil layer. Recommends that pay more attention to upbringing of shrub layerto increasing organic carbon sequestration in platycladus orientalis plantation ecosystem. |
