Abstract: Coastal wetlands are one of the most promising ecosystems for carbon sequestration, and thus their biogeochemical cycling processes have attracted considerable attention in the context of global climate change. Silicon, the second most abundant element on the Earth’s surface, plays a crucial role in processes such as rock weathering, plant growth, and organic matter decomposition, closely intertwined with carbon cycling, thus emerging as a new research frontier. Starting from the carbon-silicon processes involving plants, we provide a comprehensive review of research progress in two aspects: plant silicon use strategies and the carbon sequestration potential of phytoliths. From the perspective of plant carbon-silicon strategies, we analyze the coupled carbon-silicon cycling in coastal wetlands under global climate change, elucidating the feasibility of using silicon-rich plants such as common reeds (Phragmites australis) as model species for studying plant carbon-silicon strategies in coastal wetlands. Furthermore, we outline future research prospects from three aspects: integration of plant ecological strategy theories, coupling of soil-plant multi-processes, and mechanisms driving intra-species variation.

Key words: blue carbon, phytolith, carbon-silicon coupling, ecological strategy