岩溶碳汇稳定性是岩溶碳汇研究中迫切需要解决的关键科学问题。很多沉水植物可以利用HCO3-，在岩溶碳汇效应中起作用。然而，不同沉水植物会采用不同的无机碳利用策略，其对无机碳的固定能力也不同。本项目拟以野外监测与盆栽实验相结合，通过pH-Drift法、昼夜酸碱滴定、光合作用关键酶的测定等来研究岩溶区不同种类沉水植物无机碳利用策略与HCO3- 吸收利用能力及其与水体中无机碳源种类的关系；通过测量不同种类沉水植物的生物量、碳含量、δ13C，结合浮游植物与底泥中碳含量、δ13C，定量分析岩溶区沉水植物的碳含量及可能来源；通过测量水体中Ca2+、HCO3-、pH、碱度、温度、溶氧的昼夜动态变化与空间变化，计算水体中无机碳源的动态变化，分析沉水植物在这种动态变化中的作用。通过以上研究阐明岩溶区沉水植物无机碳利用策略及其对岩溶碳汇稳定性的影响，为水生植物原位固碳和植被恢复增加岩溶碳汇稳定性提供科学依据。

The stability of carbon sink effect related to carbonate rock dissolution is the key scientific points in the study of carbon sink. Many submerged plant can use HCO3- as a corbon source, and thus play a role in carbon sink effect related to carbonate rock dissolution. However, different kinds of submerged plants will take different inorganic carbon acquisition strategies and have the different ability to use inorganic carbon. In this project, pH-drift technology, diel acidity titration and key enzyme related to photosynthesis were used to measure inorganic carbon acquisition strategies in submerged plants in Karst and its relationship to carbon source; Plant biomass, δ13 of plant, phytoplankton and water were used to analyze carbon content and origin; Daily variation of Ca2+ , HCO3-, pH, alkalinity, water tempreture and dissolved oxygen along the river were measured to calculate the inorganic carbon time and space variation. From the above study, we want to know inorganic carbon acquisition strategies in submerged plants in Karst and its influence to the stability of carbon sink effect related to carbonate rock dissolution, and finally provide the scientific basis for using the aquatic plants to enhance the stability of carbon sink effect related to carbonate rock dissolution.