黑龙江省乌裕尔河流域有机碳迁移与沉积通量

Migration and Deposition Flux of Organic Carbon in the Wuyuerhe River Basin in Heilongjiang Province

我国目前水土流失严重,确定土壤侵蚀究竟属于碳汇还是碳源,对认识我国土壤有机碳含量具有重要意义。以黑龙江省乌裕尔河流域为研究区域,采集松嫩平原南部河水和悬浮物样品以及沉积物样品各10套,垂向剖面14条,扎龙湿地沉积柱2个,生物样品405件,根系土305件,对采集的原水进行过滤和测试。根据样品的主量元素、微量元素分析及210Pb1、37Cs、粘土矿物、磁化率、反射光谱、粒度的测试结果,开展黑龙江乌裕尔河流域土壤有机碳侵蚀通量、流域内有机质迁移方式及扎龙湿地沉积速率等研究,认为:本区影响土壤有机碳稳定性的主要因素包括温度、降雨量和土壤质地;乌裕尔河流域每年主要以溶解形式在水体中长距离迁移的方式向扎龙湿地输入有机碳,其总量估计为2.91×106kg;扎龙湿地每年沉积的有机碳总量估算为2.71×106kg,近几年的平均沉积速率约为0.34 g/(cm2.a)。根据本区的有机碳循环数据分析,乌裕尔河流域的侵蚀土壤最终进入扎龙湿地进行沉积,属于碳汇的范畴。研究结果对于查明土壤侵蚀对土壤有机碳汇/源影响提供了依据。

Soil erosion is very serious,and whether it belongs to carbon source or carbon sequestration has an important influence on the content of soil organic carbon in China.Focusing the research on the Wuyuerhe River Basin of Heilongjiang,10 sets of solids,river water samples and sediment samples,14 sets of the vertical profiles,2 sets of Zhalong wetland sediment columns,405 sets of the biological samples,and 305 sets of root soils in the south of Songnen Plain were collected and suspended,and the collected raw water is filtered and measured.According to the measurements of the major elements,trace elements,210Pb,137Cs,clay minerals,magnetic susceptibility,reflectance spectroscopy,and particle size,the research of the erosion flux of soil organic carbon in Wuyuerhe River Basin of Heilongjiang,migration patterns of watershed organic matter and deposition rate in Zhalong wetland were carried out.The results indicate that： the main factors affecting the stability of soil organic carbon include temperature,rainfall and soil texture in the study area;organic carbon inputs to the Zhalong wetland mainly in the form of long distance migration and dissolving in the water,and the total amount estimates to be 2.91×106 kg;the total organic carbon deposition of Zhalong wetland is estimated about 2.71×106 kg per year,and in recent years the average of the deposition rate is about 0.34 g/（cm^2 · a）.According to analyzing data of the organic carbon cycle in this area,the erosion soils of Wuyuerhe River Basin ultimately are deposited into the Zhalong wetland,and it belongs to the carbon sink.The results for the identification of soil erosion provide the basis on the soil organic carbon sink/source effects.