RIVERINE INORGANIC CARBON DYNAMICS： OVERVIEW AND PERSPECTIVE

1INTRODUCTION River systems are the major linkage between the land and the ocean, not only transporting carbon from terres- trial environment to the ocean, but also exchanging CO2 with the atmosphere, actively involved in the global car- bon biogeochemical cycle (RICHEY et al., 2002; COLE and CARACO, 2001). The inorganic carbon, mainly o- riginating from soil CO2, carbonate minerals and atmo- sphericCO2,constitutedthegreatpart(about 60%) ofthe riverine carbon exported to the ocean…

Riverine inorganic carbon dynamics: overview and perspective

Inorganic carbon, the great part of the riverine carbon exported to the ocean, plays an important role in the global carbon cycle and ultimately impacts the coupled carbon-climate system. An overview was made on both methods and results of the riverine inorganic carbon researches. In addition to routine in situ survey, measurement and calculation, the direct precipitation method and the gas evolution technique were commonly used to analyze dissolved inorganic carbon in natural water samples. Soil CO₂, carbonate minerals and atmospheric CO₂ incorporated into riverine inorganic carbon pool via different means, with bicarbonate ion being the dominant component. The concentration of inorganic carbon, the composition of carbon isotopes (δ¹³C and Δ¹⁴C), and their temporal or spatial variations in the streams were controlled by carbon input, output and changes of carbon biogeochemistry within the riverine system. More accurate flux estimation, better understanding of different influential processes, and quantitative determination of various inputs or outputs need to be well researched in future. Foundation item: Under the auspices of the National Natural Science Foundation of China (No. 40471120), the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20040558025), the ‘985 Project’ of GIS and Remote Sensing for Geosciences from the Ministry of Education of China (No. 105203200400006), and the Guangdong Provincial Natural Science Foundation (No. 031548) Biography: YAO Guan-rong (1980–), female, a native of Jiaocheng of Shanxi Province, Ph.D. candidate, specialized in carbon cycle and the global change. E-mail: yaoguanrong@yahoo.com.cn