Precipitation δ18O Recorded by the α‐Cellulose δ18O of Plant Residues in Surface Soils: Evidence From a Broad Environmental Gradient in Inland China

Abstract

AbstractIn order to determine the potential of α‐cellulose δ18O (δ18Ocell) data from multiple terrestrial plant species on an ecosystem level to record the δ18O data of precipitation (δ18Op), especially in relatively cold and arid environments, we collected samples of terrestrial plant residues from 104 surface soils covering a large environmental gradient (~29 to 51°N in latitude, ~81 to 124°E in longitude, ~200 to 5,100 m in elevation) in inland China. Despite the diverse vegetation types, wide range of climatic conditions and potentially complex biogeochemical processes operating within the vast study region, the δ18Ocell data show a similar spatial pattern to that of δ18Op. The results demonstrate that the measured values of δ18Ocell data have the potential to record variations in δ18Op. Further analysis indicated that the δ18Ocell data from the Tibetan Plateau were primarily controlled by the moisture sources. Interestingly, there are significant negative correlations between δ18Ocell/δ18Op and altitude on the Tibetan Plateau, implying the potential of δ18Ocell for paleoaltimetry in this region. The δ18Ocell data from the northern region of China (including the East Asian monsoon‐margin and arid central Asia) were mainly controlled by temperature, although the influence of relative humidity in the region is not negligible. Our results provide a fundamental reference for related δ18Ocell studies aimed to improve our understanding of environmental, hydrological, and climatic changes in inland China and elsewhere.