Paleoecology of the mammoth fauna of Southern Siberia during the last glacial period based on stable isotope data

Abstract

Composition of stable carbon (δ13C) and nitrogen (δ15N) isotopes of bone collagen of large mammals who inhabited Southern Siberia during MIS2 have been analysed. The results suggest significant isotopic differences of those animals from the fauna of other regions. Notably, the differences between animals from neighbouring regions may be more significant than between those from more distant areas. A summary description of the isotopic signatures of the LGP mammoth fauna from the Minusinsk depression has been presented, showing a general pattern of lower δ15N and higher δ13C values as compared to species from other regions. Variations in δ15N values may be explained by strong influence of landscape and climatic factors, in particular, the highly mosaic nature of local landscapes due to its ruggedness and altitudinal zonation. One of the possible mechanisms that could explain the observed δ13C signatures in bone collagen of the mammals is regional geochemistry, namely, the presence of developed system of mineral lakes and saline soils in the area. On saline soils, halophytic plants using the C4 type of photosynthesis and characterized by higher δ13C values, are more common. Furthermore, some halophytes, being C3 plants, are able to adapt to salinity stress and fix carbon in a way similar to C4 plants.