Sea-level rise predicted to reduce exotic mangrove distribution and biomass in coastal wetlands in southern China

Abstract

The adverse effects of sea-level rise on coastal wetlands have been extensively reported, whereas the positive effects on wetland composition have tended to receive less attention. Using a coupled hydro-vegetation model, we modeled the spatial and temporal distribution of native and exotic mangroves for 120 years in a mangrove forest in southern China in scenarios with and without sea-level rise. After approximately 50 years, the self-reinforcing feedback between mangroves and subsurface salinity is expected to create a stable ecosystem. Without sea-level rise, salt-sensitive exotic species will inhibit the growth of native mangroves, potentially leading to a more fragile ecosystem. Native mangroves are predicted to grow best under moderate sea-level rise (0.5 m). If sea level rises by 1 m, exotic mangrove populations in southern China are predicted to drastically decline. Competition between salt-tolerant and salt-intolerant plants is common in coastal wetlands, and the modeling method presented in this study may be globally applicable.