Abstract: Phytoplankton drives aquatic carbon cycle and is a key factor to understand the global carbon biogeochemical cycle. Compared with terrestrial plants, mechanisms of stable carbon isotope fractionation in algal photosynthesis are more complicated. In order to systematically understand the algal carbon isotope fractionation and its environmental application, the current relevant studies were surveyed. Taking cyanobacteria, green algae and diatoms as examples, this paper reviewed their carbon concentrating and carbon isotope fractionation mechanisms. Besides, this paper also summarized the range of algal δ¹³C and its influencing factors, and discussed the application of algal carbon isotope in the scientific fields of paleoceanography, aquatic food web and carbon cycle.

Key words: maize, soil water balance., one film used two years, semi-arid region of the Loess Plateau, farming system, yield