中国河流入海颗粒态碳通量及其变化特征

Fluxes of Particulate Carbon from Rivers to the Ocean and Their Changing Tendency in China

河流是连接海洋和陆地两大碳库的纽带,其碳通量是全球碳循环的重要环节。本文以《中国河流泥沙公报》的数据为基础,就中国河流入海颗粒态碳通量及其变化特征进行分析。结果表明:1965-2005年,中国河流入海颗粒态碳通量平均为29.57 TgC.yr-1,占河流入海碳通量的42%,其中有机碳占36.02%,无机碳占63.98%,长江、黄河和珠江的颗粒态碳通量占全国河流入海颗粒态碳通量的96.25%。从2003年开始,河流入海颗粒态碳通量呈逐年递减的趋势,但颗粒态有机碳通量在河流入海颗粒态碳通量中所占的比重有所提高。2009年,全国通过河流泥沙输送到海洋中的碳仅为6.59 TgC,为1965-2005年平均输碳量的22.3%。由此可见,颗粒态碳通量在河流碳通量中占有不可忽视的地位,为了准确评估中国河流及陆地生态系统的碳收支,应对颗粒态碳通量进行细致研究。

The river is the linkage of terrestrial and ocean carbon pools,the flux of which is a critical component of global carbon cycle.In this paper,The authors analyze the characteristics of the fluxes of particulate carbon from rivers to the ocean（FPC） in China and predicted their tendency based on the data obtained from Bulletin of Chinese River Sediment.The results indicate that,from 1965 to 2005,the annual mean FPC is 29.57TgC yr-1,36.02% of which is organic carbon,and the rest is inorganic carbon.FPC accounts for 42% of the river carbon fluxes.The quantity of particulate carbon flux from the Yangtze River,the Yellow River and the Pearl River accounts for 96.25% of the total amount in China.There is a decreasing tendency of FPC since 2003,while the ratio of organic part to the total shows an increasing tendency.The FPC of 2009 is only 6.59TgC.yr-1,which is only 22.3% of the annual mean FPC from 1965 to 2005.Therefore,it is necessary to lay emphasis on the fluxes of particulate carbon in terms of its significant role in river carbon fluxes and terrestrial carbon budget.