50年来长江源区河幔滩沉积柱土壤碳含量对气温变化的响应

位于青藏高原腹地的长江源区,是长江的发源地,在生态环境研究中占有重要地位。本文利用长江源区内五个气象台站50年来的连续监测数据,进行逐年平均温度及距平序列处理,分析了源区气温变化的时空特征;在源区内长江主要支流处采集河幔滩沉积柱样品,采用同位素测年技术来探讨长江源区河幔滩沉积柱土壤碳含量的时间变化;并将河幔滩沉积柱土壤碳含量与气温变化进行对比分析。结果表明:河幔滩沉积柱土壤全碳含量与有机碳含量具有显著相关性,并随着气温的升降相应增减;五十年以来由于受全球气候变化的影响,土壤碳含量不断增加,这将对长江源区的生态环境产生深刻的影响。

Response of the sediment carbon to the climate change for the last 5 decades in the upper Yangtze River

Source Region of the Yangtze River in the Qinghai-Tibet Plateau,is the birthplace of the Yangtze River,plays an important role in the study of the ecological environment.In this paper,50 years continuous monitoring data from five meteorological stations in Yangtze River region is processed to get the average yearly temperature and anomaly sequence,and the spatial and temporal changes in source temperature characteristics is analyzed;river beach sediment mantle column samples are collected at major tributary of the Yangtze River in the source region,and the isotope dating techniques is applied to explore spatial and temporal changes of soil carbon content in the river beach sediment column mantle in Yangtze River area;The soil carbon content in the river beach sediment column mantle is compared with temperature changes and the result is analyzed.The results showed that: The total carbon content in river beach sediment column mantle has significant correlation with soil organic carbon content,and corresponds to temperature changes.It is indicated that the soil carbon content has been increasing due to global climate change in last five decades,which will have a profound impact on the ecological environment in Yangtze River source region.