河流溶解无机碳稳定碳同位素示踪技术及其在中国河流碳循环研究中的应用OA北大核心CSTPCD

Dissolved inorganic carbon(DIC)in rivers is an important component of the global carbon cycle.The stable carbon isotope of riverine DIC(δ 13CDIC)has been extensively used to identify the sources,migration and transformation processes of carbon in river basins.In this study,we systemati-cally reviewed the influencing factors and change mechanisms of δ 13CDIC in rivers based on the latest relevant researches.It has been demonstrated that δ 13CDIC can faithfully and sensitively reflect the en-vironmental characteristics of watersheds and various surface processes,making it a useful tool for re-constructing the biogeochemical processes within the watershed carbon cycle.However,due to the complexity of carbon sources and migration and transformation processes in rivers,many details re-garding the influencing mechanisms of riverine δ 13CDIC remain unclear.We also summarized the spa-tial distribution patterns and influencing mechanisms of δ 13CDIC in China's rivers based on the report-ed δ 13CDIC data from major Chinese rivers.It has been found that the δ 13CDIC values displayed a spa-tial pattern of"high in the west and low in the east",basically reflecting the spatial distribution char-acteristics of geology,climate,and ecological environments in China.The δ 13CDIC values in rivers of the Tibetan Plateau were remarkably higher than those in other regions,and the underlying mecha-nism for this discrepancy requires further investigation.Finally,we proposed suggestions for future studies,and it is suggested to combine the use of δ 13C and radiocarbon isotope(Δ 14C),and strength-en the basic theoretical research on the stable carbon isotope fractionation of dissolved inorganic car-bon in water bodies.