Adaptability of Common Coastal Wetland Plant Populations to Future Sea Level Rise

An accelerating rate of sea level rise (SLR) is causing huge inundation pressure on coastal wetlands worldwide. Vegetation of coastal wetlands plays a key role in stabilizing the coast and accreting sediment in order to mitigate the negative impact of SLR. The ability to accrete sediment is influenced by individual species traits; however, there are insufficient information and indicators to identify differences in the adaptability of various coastal vegetations to SLR at a regional or global scale. Here, the potential adaptation of 27 plant populations in coastal wetlands subject to SLR was evaluated using a compiled global dataset and a marsh equilibrium model. Sediment accretion efficiency differed among plant populations, but most coastal marsh populations and a few mangrove populations had relatively high accretion rates; habitats with high accretion rates will have a better potential to deal with the threat of SLR. These results showed that latitude and efficiency shared a nonlinear relationship, and plant stem density and root structure were among the important factors that influenced the efficiency. Fibrous root plant populations had a greater sediment accretion efficiency than tap root plant populations, and perennial populations had a greater sediment accretion efficiency than annual plant populations. These findings can provide key parameters relating to the sediment accretion efficiency of hydrological and geomorphic models on a global scale. This study offers some novel insights into the dynamic changes in coastal wetlands following SLR that will be particularly useful in devising appropriate strategies for the protection and management of coastal wetlands.