摘要
基于稳定同位素示踪技术对长江源区植物水、土壤水、降水、河水、冰雪融水、地下冰融水及冻土层上水等水体的氢(δ2H)、氧(δ18O)稳定同位素关系进行分析.通过对比22个植物样方的稳定同位素,发现草本的δ2H和δ18O稳定同位素值均比灌木偏正.从水体稳定同位素特征的分布情况来看,植物水的直接来源为不同深度土壤水,间接来源为河水、冻土层上水、冰雪融水、降水和地下冰融水.MixSIAR模型计算结果表明长江源区灌木主要利用40～60 cm(11.1％)和 80～100 cm(11.1％)的土壤水,草本植物主要利用 0～20 cm(13.0％)和 20～40 cm(14.0％)的土壤水.土壤水对灌木的贡献比例为55％,对草本植物的贡献比例为62％,冰雪融水、降水、地下冰融水、河水、冻土层上水对灌木的贡献比例分别为7.6％、9.5％、1 1.1％、9.6％和7.6％,对草本植物的贡献比例分别为8.3％、8.2％、5.7％、7.1％和 8.9％.
Abstract
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.
基金项目
国家自然科学基金(42107063)
国家自然科学基金(42077187)
藏高原综合科学考察研究专项(第二次)(2019QZKK0405)
中国科学院青年交叉团队项目(JCTD-2022-18)
国家重点研发计划专项(2020YFA0607702)
中国科学院"西部之光"交叉团队重点实验室合作研究专项()
甘肃省创新群体项目(20JR10RA038)
甘肃省青年科技项目(20JR10RG824)
兰州理工大学红柳优秀青年人才支持计划()
NETL
NSTL
维普
万方数据