中文摘要：

湖滨带等水陆交错区土壤碳循环是全球碳循环的一个重要的组成部分,但相关方面的研究还相当缺乏。本研究选择位于苏州渔阳山保存较为良好的典型的太湖湖滨带作为实验地,并根据距离水体的远近,将湖滨带从近水体到高岗地分别设置3个实验区,对湖滨带湿地土壤水溶性有机碳（WSOC）、轻组有机碳（LFOC）2种活性有机碳进行研究,分析土壤活性有机碳与土壤因子的关系。结果表明：土壤水分明显影响土壤表层活性有机碳的含量,湖滨带土壤WSOC、LFOC在表层（0～10cm）沿土壤水分梯度的降低而减小,表现为近水区〉中水区〉远水区,且下层土壤沿水分梯度的差异变小;表层土壤活性有机碳各组分显著高于下层土壤,这与土壤有机碳和氮素变化趋势一致;WSOC、LFOC均与土壤总有机碳、土壤全氮、土壤含水率呈显著或极显著正相关;沿水分梯度土壤有机碳、全氮和土壤湿度是调控土壤活性有机碳沿水分梯度变化的主要因子。

英文摘要：

Soil carbon cycle in aquatic-terrestrial ecotone （e.g.,riparian zone） is an important component of global carbon cycle,but few researches are made o n it.Taking a typical riparian zone of Taihu Lake near Suzhou as the object,th ree experimental sites along a soil moisture gradient,i.e.,from the near of wa ter body to the high mound,were installed in this paper,with the soil water so luble organic carbon （WSOC） and light fraction organic carbon （LFOC） contents an d their correlations with soil physical and chemical factors analyzed.Soil mois ture had obvious effects on the surface soil （0-10 cm） active organic carbon.T he surface soil WSOC and LFOC contents decreased along the soil moisture gradien t,but the variation degree of these contents in deeper soil layers became small er.The WSOC and LFOC contents were significantly higher in surface soil than in subsurface soil,which was in accordance with the variation trends of soil orga nic carbon and nitrogen.In different soil layers at each site,the WSOC and LFO C were all significantly positively correlated with soil total organic carbon,t otal nitrogen,and moisture,suggesting that the latter three parameters could b e the main factors controlling soil active soil organic carbon.