紫色土丘陵坡地不同植被类型土壤活性有机碳组分的比较

探讨湖南省衡阳市紫色土丘陵坡地不同植被类型对土壤碳循环和土壤有机碳组分的影响。选取草地区（GZ）、草地森林区（GFZ）和森林区（FZ）0～10和10～20 cm土层为研究对象，通过对其活性有机碳组分的研究，为土壤碳循环和不同植被类型对有机碳组分及稳定性的影响提供理论依据。结果表明：微生物量碳和易氧化有机碳大小顺序为FZ > GZ > GFZ（P<0.05），可溶性有机碳为FZ > GFZ > GZ（P<0.05），FZ轻组有机碳显著高于GZ和GFZ；0～10 cm土层活性有机碳有效性高于10～20 cm土层；相对于GFZ，GZ中草本植物能提高土壤活性有机碳含量。

Comparison of Soil Active Organic Carbon Components between Different Vegetation Types on Sloping Land of Purple Soil

In order to explore the effects of different vegetation types on soil carbon cycle and fractions of soil organic carbon pool on hillslope land with purple soils in Hengyang City of Hunan Province, China. Selecting the soil samples of 0~10 and 10~20 cm soil layers of grassland zone(GZ), grassland-forest zone(GFZ) and forest zone(FZ), the dynamics of soil active organic carbon(SAOC) composition were investigated to provide theory basis for the influence of soil carbon cycle and different vegetation types on the fractions of organic carbon pool and its stability. The results showed that:Microbial biomass carbon and easily oxidizable organic carbon followed the order of FZ > GZ > GFZ(P<0.05); Dissolved organic carbon followed the order of FZ > GFZ > GZ(P<0.05); light fraction organic carbon was the highest in FZ(P<0.05), and the second in GZ and GFZ; The availability of active organic carbon in 0~10 cm soil layer was higher than that in 10~20 cm soil layer; In comparison with GFZ, the herb in GZ could increase the contents of active organic carbon.