Abstract: Plant functional traits offer a mechanistic framework for understanding how plant communities respond to environmental change and shape ecosystem functioning. However, despite rapid advances over the past decades, the role of functional traits in driving wetland ecosystem functioning remains less well understood than in terrestrial systems, thereby limiting effective wetland conservation and restoration. In this review, we synthesize existing evidence on how plant functional traits and functional diversity influence key wetland ecosystem functioning, such as productivity, carbon cycling, and nutrient cycling. We find that functional traits are key regulators of ecosystem functioning; therefore, targeted restoration should prioritize species with specific traits. We also call for coordinated actions across local and landscape scales to manage potential trade-offs among restoration objectives and enhance ecosystem multifunctionality. Clarifying the roles of functional diversity and wetland-specific flooding-adaptive traits in driving ecosystem functioning is identified as an important focus for future work. Moreover, a deeper understanding of how functional traits and diversity regulate wetland ecosystem functioning requires more manipulative experiments. This review highlights the role of plant traits in mechanistically linking vegetation dynamics to ecosystem functioning in wetlands.

Key words: functional trait, functional diversity, ecosystem functioning, restoration, wetland