滨海盐沼湿地蓝色碳汇功能、形成机制及其增汇潜力

盐沼湿地具有很高的碳捕获与存储能力, 是缓解全球变暖的有效蓝色碳汇(蓝碳)。未来气候变暖和海平面上升可能增加盐沼湿地的固碳能力, 其蓝碳功能越来越受到国际社会的重视。该文重点围绕盐沼湿地蓝碳形成的关键过程、光合碳分配过程及影响机制、碳沉积埋藏特征及其来源解析、盐沼湿地土壤碳库稳定性及其微生物机制、盐沼湿地蓝碳过程动态模拟及其增汇潜力等5个方面进行综述。在此基础上, 针对当前研究的不足, 提出今后的研究中需要进一步探究盐沼湿地植被海陆梯度分布格局对碳吸收能力和碳分配的影响, 土壤有机碳沉积和埋藏速率及其对全球变化的响应, 盐沼湿地土壤碳库的稳定性及其横向碳流动, 气候变化和海平面上升背景下盐沼湿地蓝碳模拟与增汇潜力评估, 以及盐沼湿地蓝碳的增汇技术和途径。以期为深入理解盐沼湿地蓝碳形成过程与机制, 预测全球变化背景下盐沼湿地蓝碳功能的潜在变化趋势和制定蓝碳增汇途径提供理论支持, 助力碳达峰、碳中和目标实现。

Blue carbon sink function,formation mechanism and sequestration potential of coastal salt marshes

Owing to the high carbon capture and storage capacity, salt marshes are considered an effective blue carbon sink for mitigating global warming. In addition, salt marshes are likely to increase their carbon sink capacity in the future in response to climate warming and sea level rise. Therefore, the blue carbon sink function of salt marshes has received increasing attention from the international research community. This study reviewed the five aspects comprising the key processes of blue carbon formation, photosynthetic carbon allocation, burial fluxes and sources of sedimentary organic carbon, stability of soil carbon pools and the associated microbial mechanisms, and the simulation and assessment of blue carbon sequestration potentials in salt marshes. On this basis, concerning the main knowledge gaps, this paper proposes further research on the effect of vegetation distribution pattern along the land-to-sea hydrologic gradient on photosynthetic carbon fixation and allocation, the response of soil organic carbon deposition and burial to global change, the stability of soil carbon pools and its lateral exchange, blue carbon simulation and assessment of blue carbon sink potential in the context of climate change and sea level rise, and technologies and approaches of blue carbon sequestration in salt marshes. Prioritizing these research topics may elucidate the formation processes and mechanisms of blue carbon, predict the changing trend of blue carbon sequestration potential under global changes, and offer new insights into achieving the goal of “carbon peak and carbon neutrality”.