Quantitative analysis of plant water sources in the Yangtze River source area
The study explored the stable isotope data relationships of hydrogen(δ2H)and oxygen(δ18O)in dif-ferent water bodies such as plant water,soil water,precipitation,river water,glacier snow meltwater,ground ice and supra-permafrost water in the Yangtze River source area based on stable isotope tracing techniques.By comparing the stable isotopes of 22 sample points,it was found that both 82H and δ18O stable isotope values of herbs were enriched than those of shrubs,while the opposite was true for δ18O isotope values.The distribution of stable isotope characteristics of water bodies showed that the direct sources of plant water were soil water at dif-ferent levels and indirect sources were river water,supra-permafrost water,ground ice,precipitation and glacier snow meltwater.The MixSIAR model was adopted to calculate the contributions of different water resources to plant water,and indicated that herbaceous plants in the Yangtze River source area primarily utilized soil water from 0-20 cm(13.0％)and 20-40 cm(14.0％),whereas shrubs primarily used soil water from 40-60 cm(11.1％)and 80-100 cm(11.1％).Shrubs received 7.6％,9.5％,11.1％,9.6％,and 7.6％of the snow and ice melt,precipitation,subsurface ice melt,river water,and water on permafrost,respectively.Herbaceous plants received 8.3％,8.2％,5.7％,7.1％,and 8.9％of these factors.
Yangtze River source areaplant water sourceisotope tracing techniqueMixSIAR model
NETL
NSTL
万方数据
维普
