Characteristics Of Soil Organic Carbon On Aerial Seeding Pinus Massoniana Plantation And Its Relationship With Litter

Forest soil carbon pool plays an important role in maintaining the global carbonbalance. Pinus massoniana is not only a typical native conifer species in subtropicalregions, but also an important timber and shelter species in southern china, and it isone of the main forest resources for aerial seeding Pinus massoniana plantation insouthern Jiangxi Province. This paper set the southern Jiangxi province as an area ofstudy and the aerial seeding Pinus massoniana plantation as the research object. Dueto the forest age restricted, there were four divisions in Pinus massoniana plantation,such as age class Ⅱ(11-20a), age class Ⅲ(21-30a), age class Ⅳ(31-40a), age classⅤ(41-50a). Then according to the four classes, setting sample plots to obtain thefield datas and combining with the laboratory analysis of soil organic carbon datasand its relationship to litter. The purpose of this paper is to provide the basis for soilcarbon pool estimated and the forest management to response to climate change. Themain findings were as follows:(1) The soil organic carbon content and carbon density of aerial seeding Pinusmassoniana plantation for different age classes were3.40-7.85g/kg and30.19-85.99t/hm2. With stand age increases,0-100cm soil organic carbon content and carbondensity exhibited that age class Ⅳ> age class Ⅴ> age class Ⅲ> age classⅡ;with the depth increasing, soil organic carbon content and the average soil organiccarbon density of10cm of soil thickness both showed the vertical distributioncharacteristics that increases with decreasing soil depth.(2) The standing crops of litter and litter C, N, P contents of aerial seeding Pinusmassoniana plantation for different age classes were0.88-1.81t/hm2,393.61-417.35g/kg,7.67-10.27g/kg,0.43-0.66g/kg. Standing crops of litter and N, P contents indifferent age classes were assumed that semi-decomposed layer higher than undecomposedlayer. Litter C, N, P storages in different age classes were0.36-0.73t/hm2,0.007-0.018t/hm2,0.0003-0.0011t/hm2, Litter C, N storages in different age classes were assumed thatsemi-decomposed layer higher than undecomposed layer.(3) Undecomposed litter layer C/N and0-10cm soil organic carbon contentshowed a significant positive correlation,0-10cm soil organic carbon contentincreased as the undecomposed litter layer C/N increasing. Canonical correlationanalysis showed that, the relationship between soil organic carbon and the littermainly caused by a positive correlation between the0-10cm soil organic carboncontent and the undecomposed litter layer C content, the undecomposed litter layerC content higher, the0-10cm soil organic carbon content larger.