ESJ56 シンポジウム S10-3
Takanori Nakano (Research Institute for Humanity and Nature, Japan)
Stable isotopes (SI) of geological and radiogenic origin (Sr, Nd, Pb etc.), abbreviated as SIG, display different biogeochemical behavior in ecological system from other SI of light-elements and bio-elements (H, C, N, O, S); the ratio of SIG of geological material varies regionally dependent on the age and the genesis, and the fractionation of SIG between coexisting phases such as liquid and solid is small or negligible. Accordingly, the ratio of SIG in ecological materials is a function of the mixing ratio of end-components generally with different SIG ratios. For example, as all elements in water and plant are essentially derived from the atmosphere and the basement rock, it is possible to quantify the contribution of each component in the water and the plant. The SIG of animal has a potential to trace the movement and the physiological process in the body, as its constituents are derived from water and plant through dietary process. The atmosphere, water, and life in Japan have been altered by materials emitted or originated from underground resources in other countries. I will show several applications of SIG to aquatic and terrestrial ecosystems and show human impacts on the system in terms of material circulation.