红树林和盐沼湿地间隙水交换过程及其碳汇潜力

The negative impact of global climate change on resources, ecology, and the environment is becoming increasingly apparent. Hence, reducing the atmospheric carbon dioxide (CO₂) concentration has become a global concern. Intertidal wetlands (e. g., mangroves and salt marshes) have strong carbon sink functions that can reduce the CO₂ concentration, 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.