Introduction: Large stocks of “blue carbon” exist in the ecosystems of coastal wetlands. This paper presents a case study of the Chinese city of Yancheng. First, through field surveys and laboratory analysis, changes in the organic carbon (OC) content in typical plant communities throughout the study area are described in detail. Second, an OC burial rate and economic value model is constructed to analyze the composition of the carbon sink values.

Outcomes/other: The results are as follows: Of the typical plant communities, Spartina alterniflora has the highest OC content (5.80 g·kg-1), followed by Suaeda glauca (4.78 g·kg-1) and Phragmites australis (3.76 g·kg-1); the contemporary OC sedimentation rates are 2.01, 1.48, and 1.22 cm·yr-1, respectively. Spartina alterniflora communities have the highest annual average carbon sink value ($418.74/ha) in the study area, followed by Phragmites australis ($176.29/ha) and Suaeda glauca ($101.54/ha).

Discussion: As a result of both the expansion of the Spartina alterniflora area and coastal erosion, the total OC value since 1987 has displayed two-stage characteristics: it first increased and then decreased.

Conclusion: In recent years, the annual average decline in OC value has ranged from approximately $82,100 to $123,100 (reference: the Sweden carbon tax provided by the World Bank, 130$/ton)

简介：沿海湿地生态系统中存在大量“蓝碳”。本文以盐城市为例。首先，通过现场调查和实验室分析，详细描述了整个研究区域内典型植物群落中有机碳（OC）含量的变化。其次，建立了一个OC埋藏率和经济价值模型来分析碳汇价值的组成。

结果/其他：结果如下：在典型的植物群落中，互花米草的OC含量最高（5.80 g·kg-1），其次是白藜（Suaeda glauca）（4.78 g·kg-1）和芦苇（3.76 g）。 ·kg-1）；当代OC沉积速率分别为2.01、1.48和1.22 cm·yr-1。互花米草群落在研究领域的最高年均碳汇价值（$ 418.74 /公顷），其次是芦苇（$ 176.29 /公顷）和碱蓬（$ 101.54 /公顷）。

讨论：由于互花米草面积的扩大和海岸侵蚀，1987年以来的总OC值表现出两个阶段的特征：先上升后下降。

结论：近年来，OC值的年平均下降幅度约为82,100美元至123,100美元（参考：世界银行提供的瑞典碳税，130美元/吨）