漓江地表水体有机碳来源

发布时间：2019-01-30 10:18

【摘要】：科学辨识河流有机碳来源是碳循环研究的关键.本文选取典型岩溶流域漓江流域为研究对象,通过同位素示踪法、相关分析法、端元混合模型,利用碳稳定同位素、C/N对其2016年7~9月有机碳来源进行研究.结果表明:(1)DIC浓度空间分布特征为:岩溶区岩溶区与非岩溶区的混合区非岩溶区;干流区DIC浓度从上游到下游递增,主要受控于流域碳酸盐岩的空间分布比例.(2)DOC是构成漓江水体TOC的主体,TOC来源以内源有机碳为主,内源碳浓度空间分布特征为:岩溶区混合区非岩溶区,可能与岩溶区水生植物丰茂、碳酸酐酶活性较强有关,TOC中内源碳的浓度介于1.02~5.14 mg·L~(-1),平均为2.54 mg·L~(-1);TOC中内源碳的比例空间分布差异不大,平均为73.07%.(3)POC浓度、POC中内源碳的浓度及POC中内源碳的比例空间分布差异不大,POC来源以外源碳为主,POC中内源有机碳浓度介于0.01~0.16 mg·L~(-1),平均为0.05mg·L~(-1),水生生物量对漓江流域POC贡献平均为17.31%.(4)DOC浓度及内源DOC浓度空间分布均为:岩溶区混合区非岩溶区,DOC主要来源于水生生物的初级生产力,DOC中内源碳的浓度介于0.97~5.10 mg·L~(-1),平均为2.48 mg·L~(-1);DOC中内源碳的比例空间分布差异不大,平均为79.51%.研究水生光合生物对流域有机碳的影响,可以为岩溶碳汇稳定性科学问题的解答提供基础.
[Abstract]:Identifying the source of organic carbon in rivers scientifically is the key to the study of carbon cycle. In this paper, the source of organic carbon from July to September of 2016 was studied by means of isotope tracer method, correlation analysis method and end-element mixed model. Carbon stable isotope and C / N were used to study the source of organic carbon in Lijiang River basin. The results show that: (1) the spatial distribution characteristics of DIC concentration are: the mixed area of karst area and non-karst area; The concentration of DIC in the main stream is increasing from upstream to downstream, which is mainly controlled by the spatial distribution ratio of carbonate rocks in the basin. (2) DOC is the main component of TOC in the Lijiang River, and the internal source organic carbon is the main source of TOC. The spatial distribution characteristics of endogenous carbon concentrations are as follows: the non-karst areas in mixed karst areas may be related to the aquatic plants Fengmao and carbonic anhydrase activity in karst areas. The concentration of endogenous carbon in TOC is between 1.02 and 5.14 mg L ~ (-1). The average was 2.54 mg L ~ (-1); There was no significant difference in the proportion spatial distribution of endogenous carbon in TOC, with an average of 73.07. (3) the concentration of endogenous carbon in POC and the proportion of endogenous carbon in POC were not significantly different from those in POC. The concentration of endogenous organic carbon in POC ranged from 0.01 to 0.16 mg L ~ (-1), with an average of 0.05mg L ~ (-1). The contribution of aquatic biomass to POC in Lijiang River basin was 17.31 on average. (4) the spatial distribution of DOC concentration and endogenous DOC concentration were as follows: in mixed karst area, DOC was mainly derived from the primary productivity of aquatic organisms. The concentration of endogenous carbon in DOC was between 0.97 mg L ~ (-1) and 5.10 mg L ~ (-1), with an average of 2.48 mg L ~ (-1). The spatial distribution of endogenous carbon in DOC was not significant, with an average of 79.51. The study of the effects of aquatic photosynthetic organisms on organic carbon in the watershed can provide a basis for the scientific solution of the stability of karst carbon sinks.
【作者单位】：西南大学地理科学学院岩溶环境重庆市重点实验室;中国地质科学院岩溶地质研究所/国土资源部广西岩溶动力学重点实验室;
【基金】：中国地质科学院基本科研业务费专项(YYWF201639) 广西自然科学基金项目(2016GXNSFAA380064) 重庆市自然科学基金项目(CSTC2016JCYJYS0003)
【分类号】：X143

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