中文摘要：

选取东北三江平原沼泽湿地5种土地利用方式，共16个土壤剖面，对土壤有机碳储量分布特征进行了研究．结果表明，不同土地利用方式下，土壤剖面有机碳含量与有机碳密度均呈自上而下降低的趋势，且随着深度的增加，垂直差异变小．开垦降低了土壤有机碳含量和有机碳密度，并改变了其在表层的分布结构特征．初步估算5种土地利用方式下土壤有机碳储量分别为：沼泽湿地1．58×10^4t／km^2、退耕还湿地1．23×10^4t／km^2、林地1．01×10^4t／km^2、水田0．85×10^4t／km^2、旱田0．99×10^4t／km^2．开垦降低了湿地土壤有机碳储量，且对耕地的影响大于林地，而退耕还湿有利于土壤有机碳的固定及储量的增加．

英文摘要：

Soil organic carbon （SOC） storage in soil of lm-depth profiles （totally 16） under 5 different land-use types in Sanjiang Plain, Northeast China was analyzed. Content and density of SOC decreased in vertical distribution under different land-use types, and the tendency of variation descended with the increase of depth. Reclamation reduced the content and density of SOC, and changed the distribution structure in topsoil. A preliminary estimate showed that the SOC storage of lm-depth was 1.58×10^4t/km^2 in wetland, 1.23×10^4t/km^2 in abandoned land, 1.01×10^4t/km^2 in woodland, 0.85×10^4t/km^2 in paddy land and 0.99×10^4t/km^2 in glebe. It concluded that reclamation reduced SOC storage of wetland, and the effect was more significant in farmland than in woodland. Wetland restoration could be beneficial to soil carbon sequestration and would increase the soil organic carbon storage.