摘要
分析冰川中溶解性有机质(dissolved organic matter,DOM)的迁移转化特征是评估冰川消融对下游生态环境效应的重要依据,但冰川表层雪中DOM在冬春季节的迁移转化特征尚不明确。本文以达古冰川冬春季节表层雪和春季冰川径流为研究对象,使用傅里叶变换离子回旋共振质谱(FT-ICR MS)对表层雪和径流中DOM进行分子层次表征。结果显示:达古冰川冬春季节表层雪中DOM化学组成非常丰富,主要包括脂类、多肽类、不饱和烃类,还含有少量的酚类、多环芳烃类和糖类,来源包括微生物活动和陆源性输入。春季径流中DOM的主要来源是陆源性输入,受人类活动影响较大。分析不同季节表层雪DOM的分子组成变化,发现冬季低温环境有利于表层雪中脂类、多肽类和含S类DOM分子的富集,春季气温升高则有利于表层雪中多肽类、不饱和烃类和含N类DOM分子的富集。比较春季径流和表雪中DOM的分子组成变化,发现径流中杂原子类DOM含量降低,微生物来源的脂类和多肽类DOM含量降低,陆源性的酚类和多环芳烃类含量显著增加,说明径流中DOM的生物活性降低而光反应活性增加。因此随着冰川持续消融大量的冰川融水将DOM带入下游水环境,在微生物活动和光反应过程的共同作用下增加温室气体CO_(2)的排放,增强温室效应。
Analyzing the evolution characteristics of dissolved organic matter(DOM)in glaciers is an important basis for evaluating the biogeochemical effect of glacier melting on downstream ecological environment.Howev-er,the evolution characteristics of DOM in surface snow in winter and spring are still unclear.In this study,the surface snow of Dagu Glacier and glacial runoff in winter and spring was studied,and DOM in the surface snow was characterized at molecular level by using Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS).The results indicate that the chemical composition of DOM in the surface snow of Dagu Glacier dur-ing winter and spring exhibits a diverse range,primarily consisting of lipids,peptide-like,unsaturated com-pounds,and minor quantities of polyphenolic,condensed aromatics,and sugars compounds.The sources of these components include both microbial and terrestrial origins.The main source of DOM in spring runoff is ter-restrial inputs,which is greatly affected by human activities.The molecular composition of DOM in surface snow in different seasons was analyzed,and it was concluded that the low temperature environment in winter was conducive to the enrichment of aliphatic,peptide-like and S-containing DOM molecules in surface snow,and the higher temperature in spring was conducive to the enrichment of peptide-like,unsaturated hydrocarbons and N-containing DOM molecules in surface snow.Comparing the molecular composition of DOM in spring runoff and surface snow,it was found that the content of heteroatomic DOM in runoff decreased,the content of aliphatic and peptide-like DOM from microbial source decreased,and the content of terrestrial sources of poly-phenolic and condensed aromatics significantly increased,indicating that the biological activity of DOM in run-off decreased and the photoreactive activity increased.The continuous melting of glaciers leads to the influx of a significant amount of glacial meltwater into downstream water environments.This influx,combined with micro-bial activities and light reaction processes,results in an increased emission of greenhouse gas CO_(2) and intensifies the greenhouse effect.
作者
冯琳
刘艳梅
马兴刚
徐建中
王世金
张伏
FENG Lin;LIU Yanmei;MA Xinggang;XU Jianzhong;WANG Shijin;ZHANG Fu(Aba Teachers University,Wenchuan 623002,Sichuan,China;Yulong Snow Mountain National Field Observation and Research Station for Cryosphere and Sustainable Development,State Key Laboratory of Cryospheric Science,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;School of Oceanography,Shanghai Jiao Tong University,Shanghai 200030;Dagu Glacier Scenic Area Management Bureau,Heishui 624000,Sichuan,China)
出处
《冰川冻土》
CSCD
2024年第1期77-88,共12页
Journal of Glaciology and Geocryology
基金
阿坝师范学院人才专项(AS-RCZX2023-04)
阿坝师范学院校级重点项目(ASA21-01)
阿坝师范学院达古冰川研究所(中心)项目(AS-DTPT 2023-072)资助
阿坝州应用技术研究与开发资金项目(R21YYJSYJ0005)。
