红树林和盐沼湿地间隙水交换过程及其碳汇潜力

Porewater Exchange and the Related Carbon Sink Potential in Mangroves and Saltmarshes

全球气候变化对资源、生态和环境的负面影响日益显现,降低大气CO浓度已经成为全球关注的焦点。潮间带湿地(如红树林和盐沼)具有很强的碳汇功能,是降低CO浓度和减缓全球气候变化的重要途径。红树林和盐沼作为重要的海岸带蓝碳生态系统,其土壤具有极高的储碳能力。由于受潮汐和降雨等驱动力的控制,红树林和盐沼土壤间隙水碳交换过程在海岸带蓝碳汇估算中具有较大的不确定性。同时,红树林和盐沼间隙水碳交换过程也是海岸带蓝碳汇相关研究中的前沿性科学问题,具有较大的挑战性。红树林和盐沼间隙水交换促使大量沉积物中的碳输出并存储于海洋,其可能是除了湿地碳埋藏之外的另一个重要碳汇,但目前对此尚未开展系统研究。总结论述了红树林和盐沼生境土壤间隙水交换速率及其携带蓝碳通量和控制因素,期望在对全球红树林和盐沼生态系统蓝碳收支和碳汇潜力进行评估中对其土壤间隙水过程携带的蓝碳通量引起足够的重视。这将深化对红树林和盐沼生态系统碳收支平衡和循环过程的认识,进而在全球气候变化的背景下,为更好地发挥海岸带蓝碳汇功能、促进红树林和盐沼生态系统建设和保护以及海岸带可持续发展提供科学支撑。

The negative impact of global climate change on resources,ecology,and the environment is becoming increasingly apparent.Hence,reducing the atmospheric carbon dioxide(CO)concentration has become a global concern.Intertidal wetlands(e.g.,mangroves and salt marshes)have strong carbon sink functions that can reduce the COconcentration,thus mitigating global climate change.Mangroves and salt marshes are important coastal blue carbon ecosystems characterized by high soil carbon storage.Porewater exchange and associated carbon exchange driven by tides and rainfall in mangroves and salt marshes are challenging issues when estimating the effects of coastal blue carbon sinks.Large amounts of porewater-derived sediment carbon outwellings remain in the ocean and may represent an important carbon sink;however,they are poorly understood,despite being potentially significant components of the salt marsh carbon budget.This review aims to quantify the porewater exchange rate and related carbon fluxes,analyze their driving mechanisms,and reassess the carbon budgets and carbon sink potentials of mangroves and salt marshes.This study promotes understanding the carbon balance and cycle processes associated with mangrove and salt marsh ecosystems,and provides a scientific basis for the construction,protection,and sustainable development of coastal blue carbon sinks in the context of global climate change.