北亚热带土地利用变化对土壤有机碳垂直分布特征及储量的影响

利用野外调查的方法,研究了北亚热带地区土地利用变化对土壤有机碳的垂直分布特征及储量的影响.研究结果表明:(1)除茶园土壤外,不同林分土壤有机碳含量均以0～10cm土层最大,随着土层深度的增加,含量总体表现为下降的趋势;茶园土壤有机碳含量在0～30cm土层范围内增加,30cm以后表现下降的趋势;(2)次生林转变成农耕地以后土壤有机碳含量平均下降21.1%,而转变成集约经营早竹林后,土壤有机碳含量平均下降近48.5%;1m深度以内,土壤有机碳平均含量由高到低的顺序为:茶园、灌木林、次生林、粗放经营毛竹林、集约经营毛竹林、马尾松林、农耕地、杉木林和早竹林;(3)土壤有机碳储量随土层深度变化的趋势和土壤有机碳含量变化趋势基本一致;次生林转变成长期经营的农耕地后,土壤有机碳储量下降22.5%,而转变成长期集约经营早竹林后土壤有机碳储量则下降51.4%9种土地利用类型中,土壤有机碳储量由高到低的顺序为:茶园、灌木林、次生林、粗放经营毛竹林、马尾松林、农耕地、集约经营毛竹林、杉木林和早竹林.

Effects of Land-use Change on Vertica l D istr ibution and Storageof So ilOrgan ic Carbon in North Subtropica l Area s

This paper deals with the effects of land-use change on the vertical distribution and storage of soil organic carbon(SOC) in north subtropical areas by means of field survey.The results showed that: (1)The contents of SOC of the top soil profile (0 - 10 cm) were the greatest, compared with the other soil profiles(10 - 100 cm) in the eight land-use types except the tea garden, which showed an increase from 0 to 30 cm and a decrease from 30 to 100 cm in depth. (2)When the natural secondary stands were changed into arable land, the average SOC content decreased by 21.1%, but when changed into the Phyllostachys praecox stands, the average SOC content decreased by 48.5%. In the one meter soil profile, the contents of SOC from the highest to the lowest was ranked as follows: tea garden, shrub, the natural secondary stands, extensive Phyllostachys edulis stands,intensive Phyllostachys edulis stands, masson pines, arable land, Chinese fir, Plyllostachys praecox stands. (3) The vertical distribution of SOC storage showed the same tendency as the SOC content; after the natural secondary stands was converted into arable land, the SOC storage decreased by 22.5%, while converted into Phyllostachys praecox stands, the SOC storage decreased by 51.4%; In the one meter soil profile, the storage of SOC from highest to lowest was ranked as follows: tea garden, shrub, the natural secondary stands, extensive Phyllostachys edulis stands, masson pines, arable land, intensive Phyllostachys edulis stands, Chinese fir and Phyllostachys praecox stands.