Abstract: Applying the spatial series to replace time series,the soils of 0~40 cm depth in four typical sampling plots,grassplot (GT),frutex and grassplot (FG),frutex (FX),and arbor and frutex (AF),were selected to study the concentration of soil dissolved organic carbon (DOC),E₂₈₀ value,specific ratios of E₂₅₀/E₃₆₅ and the influential factors. The four communities on hillslope with purple soils were similar and typical,and represented four different successive stages in Hengyang City of Hunan Province. The results showed that:The concentration of soil DOC significantly increased with the process of re-vegetation (P<0.05);Correlation analysis showed that soil DOC was negatively correlated with soil bulk density (BD) and heavy fraction of organic carbon (HFOC) (P<0.01);was positively correlated with soil organic carbon (SOC),total N (TN),available N (AN),available P (AP),soil microbial biomass carbon (SMBC) and light fraction of organic carbon (LFOC) (P<0.05 or P<0.01);was not correlated with total P (TP),available K (AK) and pH value(P > 0.05). The above results indicated that soil DOC could be used as an index of soil fertility because of its close correlation with soil fertility factors.

Key words: Soil dissolved organic carbon, Soil factors, Re-vegetation, Purple soils

摘要： 本文以典型的衡阳市紫色土丘陵坡地不同植被恢复阶段为研究对象，采用空间代替时间序列的方法，选用立地条件基本相似的草本阶段（Grassplot，GT）、灌草阶段（Frutex and grassplot，FG）、灌丛阶段（Frutex，FX）和乔灌阶段（Arbor and frutex，AF），通过调查取样和实验分析，对不同恢复阶段0~40 cm土层土壤水溶性有机碳，E₂₈₀、E₂₅₀/E₃₆₅、E₂₄₀/SOC及其影响因素进行了研究。结果表明：随着植被恢复的进行，土壤水溶性有机碳含量显著增加（P<0.05）；土壤水溶性有机碳含量与土壤容重、重组有机碳呈极显著负相关（P<0.01），与土壤有机碳、全氮、碱解氮、速效磷、土壤微生物生物量碳、轻组有机碳呈显著或极显著正相关（P<0.05或P<0.01），与全磷、速效钾、pH值相关性不明显（P>0.05）。综上所述，土壤水溶有机碳与土壤肥力关系密切，可作为评价土壤肥力性状的生物学指标。

关键词: 土壤水溶性有机碳, 土壤因子, 植被恢复, 紫色土