Yin Guangcai, Zhou Guoyi, Zhang Deqiang, Wang Xu, Chu Guowei, Liu Yan
College of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510090, China.
Ying Yong Sheng Tai Xue Bao. 2005 Sep;16(9):1655-60.
The total flux and concentration of total organic carbon (TOC) in hydrological processes in coniferous and broad-leaved mixed forest of Dinghushan were measured from July 2002 to July 2003. The results showed that the TOC input by precipitation was 41.80 kg x hm(-2) x yr(-1), while its output by surface runoff and groundwater (soil solution at 50 cm depth) was 17.54 and 1.80 kg x hm(-2) x yr(-1), respectively. The difference between input and output was 22.46 kg x hm(-2) x yr(-1), indicating that the ecosystem TOC was in positive balance. The monthly variation of TOC flux in hydrological processes was very similar to that in precipitation. The mean TOC concentration in precipitation was 3.64 mg x L(-1), while that in throughfall and stemflow increased 6.10 and 7.39 times after rain passed through the tree canopies and barks. The mean TOC concentration in surface runoff and in soil solution at 25 and 50 cm depths was 12.72, 7.905 and 3.06 mg x L(-1), respectively. The monthly TOC concentration in throughfall and stemflow had a similar changing tendency, showing an increase at the beginning of growth season (March), a decrease after September, and a little increase in December. The TOC concentration in runoff was much higher during high precipitation months. No obvious monthly variation was observed in soil solution TOC concentration (25 and 50 cm below the surface). Stemflow TOC concentration differed greatly between different tree species. The TOC concentration in precipitation, throughfall, and soil solution (25 and 50 cm depths) decreased with increasing precipitation, and no significant relationship existed between the TOC concentrations in stemflow, surface runoff and precipitation. The TOC concentrations in the hydrological processes fluctuated with precipitation intensity, except for that in stemflow and soil solutions.
2002年7月至2003年7月，对鼎湖山针阔混交林水文过程中总有机碳（TOC）的总通量和浓度进行了测定。结果表明，降水输入的TOC为41.80 kg·hm⁻²·a⁻¹，而地表径流和地下水（50 cm深度土壤溶液）输出的TOC分别为17.54和1.80 kg·hm⁻²·a⁻¹。输入与输出的差值为22.46 kg·hm⁻²·a⁻¹，表明生态系统TOC处于正平衡状态。水文过程中TOC通量的月变化与降水的月变化非常相似。降水中TOC的平均浓度为3.64 mg·L⁻¹，而穿透雨和树干茎流中TOC的平均浓度在雨水穿过树冠层和树皮后分别增加了6.10倍和7.39倍。地表径流以及25 cm和50 cm深度土壤溶液中TOC的平均浓度分别为12.72、7.905和3.06 mg·L⁻¹。穿透雨和树干茎流中TOC的月浓度变化趋势相似，在生长季开始时（3月）升高，9月后降低，12月略有升高。高降水月份径流中TOC浓度高得多。土壤溶液TOC浓度（地表以下25 cm和50 cm）未观察到明显的月变化。不同树种的树干茎流TOC浓度差异很大。降水、穿透雨和土壤溶液（25 cm和50 cm深度）中的TOC浓度随降水量增加而降低，树干茎流、地表径流与降水中的TOC浓度之间无显著关系。除树干茎流和土壤溶液外，水文过程中的TOC浓度随降水强度波动。
