Carbon isotope and environmental changes in lakes in arid Northwest China

The stable carbon isotope composition(δ~(13) C) of lacustrine sediments, which can record changes in past environmental conditions such as the C4/C3 terrestrial vegetation composition, has been widely used for the reconstruction of terrestrial ecosystems and global climate changes. It has also been widely used in paleolimnological studies in arid northwestern China. In recent years, however, an increasing number of studies have enriched the environmental significance reflected by the stable carbon isotope geochemistry of lakes; therefore, the interpretation of lake δ~(13) C variations in paleoenvironmental reconstructions should be carefully evaluated from various aspects. In this paper, previous studies from the past several decades on the lacustrineδ~(13) C variations in arid northwestern China were reviewed, and the possible mechanisms of the δ~(13) C variations were discussed.Our study will provide a reference for the application of carbon isotope geochemistry in paleoenvironmental reconstructions.