中文摘要：

以中亚热带米槠常绿阔叶次生林和杉木人工林为研究对象,定位观测了穿透雨和树干径流中可溶性有机质（DOM）浓度的变化,分析了DOM腐殖化程度和芳香性特征.结果表明：研究区米槠次生林穿透雨可溶性有机碳（DOC）浓度的变化幅度明显高于杉木人工林,且前者DOC浓度显著高于后者,相比大气降水DOC浓度,分别增加了7.2和3.2倍.杉木人工林树干径流DOC浓度约为米槠次生林的2.5倍,且两种林分树干径流DOC浓度均呈现旱季高于雨季的趋势.相关分析结果显示：米槠次生林和杉木人工林树干径流DOC浓度均与其相应的水量呈极显著负相关.米槠次生林穿透雨DOM腐殖化程度和芳香性均显著高于杉木人工林;相反,杉木人工林树干径流DOM腐殖化程度和芳香性均显著高于米槠次生林.说明米槠次生林穿透雨中DOM结构较复杂且具有较多的芳香族化合物,而杉木人工林树干径流中DOM结构复杂于米槠次生林.米槠次生林和杉木人工林穿透雨和树干径流的DOM数量和质量具有明显差异,对土壤有机碳的积累可能产生重要影响.

英文摘要：

In this paper, monthly variation of dissolved organic matter （DOM） concentrations as well as humification and aromaticity indices in throughfall and stemflow from secondary broadleaved Castanopsis carlesii （BF） forest and Cunninghamia lanceolata plantation （CP） were measured. The DOC concentrations in throughfall were significantly higher with greater variation in BF than in CP. The concentrations of DOC in throughfall and CP forests, respectively. The DOC were averagely 7.2 and 3.2 times of those in rainfall in BF concentrations of stemflow in CP were averagely 2.5 times as much as those in BF, and the DOC concentrations in stemflow tended to be greater in dry season than in rain season for the two forests. A significantly negative relationship was found between the DOC concentrations in stemflow and the amounts of stemflow for both BF and CP. Moreover, the humification and aromaticity indices of DOM in throughfall in BF was significantly greater than in CP. In contrast, the humification and aromaticity indices of DOM from sternflow of CP were signifi- cantly greater than those of BF. This result indicated that the structure of DOM from throughfall was more complex in BF than in CP, and the structure of DOM from stemflow was vice versa. These re-suhs indicated that DOM in stemflow and throughfall showed significant variations in quantity and quality between BF and CP and may greatly impact the accumulation of soil organic carbon.