中文摘要：

为了解不同降雨条件下碳在常绿阔叶林和针叶林内部的迁移特征,对亚热带米槠次生林和杉木人工林在不同降雨量下林冠层可溶性有机碳（DOC）浓度的变化特征进行分析。结果发现：降雨量大于10mm时,米槠和杉木树干径流量与胸径呈幂函数正相关（R2〉0.81和R2〉0.88）,米槠树干径流中DOC浓度与胸径呈幂函数负相关（R2〉0.37）;相反,杉木树干径流中DOC浓度与胸径呈幂函数显著正相关关系（R2〉0.69,P〈0.05）。米槠次生林穿透雨中DOC浓度相对大气降雨中DOC浓度平均增量大于杉木人工林,且前者增量的变化幅度也远大于后者,表明降雨量对米槠次生林穿透雨DOC浓度的影响较杉木人工林大;总体而言,米槠次生林树干径流DOC浓度（48.8mg/L）显著低于杉木人工林（23.4mg/L）（P〈0.05）。随着降雨量增大,米槠次生林树干径流DOC浓度呈现下降趋势,而杉木人工林则呈现一定的递增趋势,说明树种的差异可引起树干径流DOC浓度对降雨变化的响应不同,降雨历时同样对穿透雨和树干径流DOC浓度具有显著性影响。

英文摘要：

To determine the characteristic of carbon transport under different rainfall event in the secondary broadleaved forest and coniferous forest,the dissolved organic carbon（DOC）concentration which from the canopy was measured and dynamics of DOC concentration change was analyzed during different rainfall conditions in a secondary broadleaved forest of Castanopsis carlesii（BF）and plantation forest of Cunninghamia lanceolata（Chinese fir）（CF）.The results showed that a positive power function correlation（R2〉0.81 for the Castanopsis carlesii and R2〉0.88 for the Chinese fir）was found from the stemflow of Castanopsis carlesii and Chinese fir with the diameter at breast height（DBH）.DOC concentration of the stemflow was negative power function correlation with its DBH for Castanopsis carlesii.Instead,there was a significant and positive power function correlation between the stemflow DOC concentration and DBH in Chinese fir（R2〉0.69,P〈0.05）.The relative increment of DOC concentration in throughfall happened in BF versus that in precipitation was higher than in CF,and that the range of increment for BF was greatly higher than CF,indicated that the effects of precipitation on throughfall in BF was greater than that in CF.Overall,the stemflow DOC concentration in BF（48.8mg/L）was significant higher than that in CF（23.4mg/L）（P〈0.05）.In addition,with the increase of precipitation,the stemflow DOC concentration of BF appeared a decreased trend,crosscurrent in CF,which demonstrated that different response of stemflow DOC concentration to change of rainfall with different tree species,and also the duration of rainfall performance a significant influence on concentration of DOC in throughfall and stemflow.