Simulation of the geographical distribution of global potential wetlands under climate change using an ensemble species distribution model

Abstract

Simulating potential wetlands is crucial to mitigating wetland degradation and loss. However, existing simulation approaches have focused on terrain indices while not considering climate variables, making it challenging to predict potential wetland changes under global warming conditions. In response to these challenges, an ensemble species distribution model (BIOMOD2) was used to simulate the spatial distribution of potential wetlands under different climate change scenarios. Multiple environmental variables, including climate data from the Sixth Coupled Model Intercomparison Project Phase 6 (CMIP6), topographic wetness index, and normalized difference vegetation index, were used. The impact of climate change on the distribution of global potential wetlands in the next 60 years was analyzed. Our findings indicate that climate factors are the dominant variables affecting the distribution of potential wetlands. The mean temperature in the warmest quarter had the highest contribution (0.469), followed by annual mean temperature (0.229) and topographic wetness index (0.225). Approximately 2.29 × 107 km² of potential wetlands currently exist globally. Due to climate change, this number will decrease by at least 2.03 × 10⁵ km² by the 2060 s and by at least 3.97 × 10⁶ km² by the 2080 s. Suitable areas for wetlands will migrate to higher altitude areas, especially with more significant changes under the high climate sensitivity scenario. Our results contribute to identifying priority areas for restoration and conservation and are significant for maintaining wetland biodiversity in the context of climate change.