Availability of the stable isotope ratios as the standard indicator in basin research

Abstract

By using the stable isotope ratios as an indicator, it is possible to analyze the biological and chemical processes in an ecosystem from the viewpoint of their chemical reactions. For example, the active sites of bioelements cycling in the watershed, they are the eutrophic site and oxidation-reduction boundary, can be detected by carbon and nitrogen isotope ratios. Moreover, it is possible to determine the trophic levels of various organisms and foodchain structures. In the future, the analytical technique of material flow which linked natural ecosystems with human activity will be proposed from the viewpoints of the stable isotopes. Approaches not only natural sciences but also from interdisciplinary field are necessary for basin research. The role of stable isotopes as the all-around standard indicator in basin research will soon gain widespread acceptance.