水生生物光合作用对雪玉洞岩溶水体中CDOM的影响  

Effects of Photosynthesis of Submerged Aquatic Plants on CDOM in a Karst Water System: A Case Study from Xueyu Cave, Chongqing, China

作　　者：范佳鑫 蒋勇军 贺秋芳 王家楠 何瑞亮 张彩云 马丽娜 汪啟容 FAN Jia-xin;JIANG Yong-jun;HE Qiu-fang;WANG Jia-nan;HE Rui-liang;ZHANG Cai-yun;MA Li-na;WANG Qi-rong(Chongqing Key Laboratory of Karst Environment,School of Geographical Sciences,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学地理科学学院岩溶环境重庆市重点实验室,重庆400715

出　　处：《环境科学》2019年第6期2657-2666,共10页Environmental Science

基　　金：重庆市自然科学基金项目(cstc2017jcyj-ysxx0004;cstc2018jcyj-yszx0013);国家重点研发计划项目(2016YFC0502306);国家自然科学基金项目(41472321)

摘　　要：溶解有机质(DOM)作为岩溶水体碳汇的重要组成部分,其来源、分布和迁移变化对研究岩溶碳汇的组成、结构和通量具有重要意义,其组成和结构特征常用有色溶解有机质(CDOM)反演.本研究于旱季每月采集重庆雪玉洞洞内地下水和洞外地表水,通过地下河从洞内向洞外的流动过程中水化学和CDOM光谱特性的变化,分析CDOM的变化影响因素,为研究岩溶水体DOM碳汇通量提供理论基础.结果表明:(1)雪玉洞岩溶水中CDOM以小分子易降解的内源有机质为主,类色氨酸和类酪氨酸组分占60%以上;(2)雪玉洞地下水中的CDOM主要受地下水微生物的降解作用影响,地下水流动过程中有少量易降解有机质被微生物降解,TOC和DOC含量略有降低,CDOM腐殖化程度略有增强;(3)雪玉洞地表水CDOM主要受水池中水生植物光合作用控制,水生植物生长处TOC和DOC含量明显升高,CDOM内源特征和小分子组分明显增多.Dissolved organic matter(DOM) in karst water is one of the most important carbon sink components,whose origins,distributions,and transport processes are of significance to carbon sink studies. Chromophoric dissolved organic matter(CDOM) can be utilized to express the composition and structural properties of DOM. In this paper,water samples were collected monthly from Xueyu Cave in a karst underground river from both inside and outside the cave. The changes in hydrochemistry and CDOM spectral characteristics as well as the influencing factors for CDOM changes were studied,with the aim of providing experimental support for carbon sink fluxes in karst processes. The main results were as follows.(1) The dominant type of CDOM in Xueyu Cave karst water consisted of small molecular weight organic matter that was autochthonously derived and easily bio-degraded,and the tryptophan-like and tyrosine-like components accounted for more than 60% of the total CDOM.(2) The most effective influencing factor inside the cave was microbes,which degraded the small molecular DOM in groundwater and induced slight decreases in the TOC and DOC concentrations;they also increased the humic index(HIX).(3) However,the dominant factor outside the cave was submerged aquatic plant photosynthesis,which induced significant increases in the TOC and DOC concentrations and autochthonous small molecular weight DOM contents.

关 键 词：岩溶水 水生光合作用 有色溶解有机质(CDOM) 溶解有机碳(DOC) 微生物降解 

分 类 号：X142[环境科学与工程—环境科学]