Carbon isotopic composition of modern soil and paleosol as a response to vegetation change on the Chinese Loess Plateau

The relationship between the carbon isotopic composition of paleosols and paleovegetation on the Loess Plateau is still unclear. One of the main reasons is that we are short of knowledge about the characteristics of the carbon isotopic composition of modern soil in this area. A preliminary investigation of the carbon isotopic compositions of the modern soil and the loess/paleosol sequence on the Loess Plateau shows that the carbon isotopic composition of modern soil is consistent with the distribution of modern plants on the Loess Plateau, where the ecosystem is dominated by a mixture Of C-4 and C-3 plants. Comparing the delta C-13 values of modern soil and loess-paleosol sequences from the Xunyi profile, we conclude that C-3 plants dominated the landscape during loess sediment stages, while C-4 plants expanded during paleosol stages.