Modelling the susceptibility of wetland plant species under climate change in the Mekong Delta, Vietnam

Wetlands are important ecosystems that provide many critical services for ecology and human communities. In the Mekong Delta (MD), Vietnam, the combined effects of climate change and sea level rise (SLR) threaten coastal mangrove forest wetlands, while inland Melaleuca forest wetlands are affected by regional changes in climate. Hence, it is essential to understand the impacts of climate change and SLR on these wetlands, particularly on the dominant species, which are integral to the structure and function of each wetland type. However, future climate suitability for wetland species is not yet well documented and well researched for the region. Therefore, this study examines the potential impacts of climate change and SLR on the three dominant species of these wetland types, Avicennia alba (A. alba) and Rhizophora apiculata (R. apiculata) in coastal mangrove forest wetlands and Melaleuca cajuputi (M. cajuputi) in inland Melaleuca forest wetlands, utilizing an ensemble modelling approach. The species occurrence points, bioclimatic and eco-physiological variables were used to model habitat suitability for the three species under current and future climate scenarios, RCP4.5 and 8.5 for 2050 and 2070. The projected reduction in habitat suitability of A. alba, R. apiculata, and M. cajuputi by mean values of 27.9%, 28.7% and 30.0%, respectively by the year 2070 indicates the vulnerability of the wetland species to climate change impacts. Increases in temperature, and in seasonal variation in precipitation and temperature, and SLR were key driving factors responsible for the losses of suitable habitat. Our findings provide useful information and data sources for development of plans and strategies to protect and conserve the wetlands from future climate change impacts.