Evaluating current and future potential climatic suitability for epiphytic orchids in the Congo Basin
Abstract
Background. The tropical forests of the Congo Basin support a rich diversity of vascular epiphytic community. Among vascular epiphytes, the Orchidaceae alone makes up more than 60% of all diversity in the region. In the Congo Basin Forest, severe threats to epiphytic orchids stemming from forest cover loss and environmental changes include elevated temperatures, prolonged periods of droughts, and reduced rainfall.
Method. In this study, we used ecological niche modeling, climate change scenarios, and spatial analyses to identify patterns of species richness, forecast potential climate refugia, and novel areas of climatic suitability for epiphytic orchids in 2021-2040. We also evaluated the overlap of the current network of protected areas with hotspots of climatic suitability for epiphytic orchids in the Congo Basin.
Results. Our models forecasted that, of the 16 epiphytic orchid species studied, nine could lose more than 30% of their current climatically suitable range (range contraction). Additionally, less than 25% of hotspots of potential climatic of suitability for epiphytic orchids overlapped with the network of protected areas in the Congo Basin. Our models also forecasted stable areas (climate refugia) , as well as novel climatic suitability areas across the biogeographic extent of the Congo Basin and beyond. Climate refugia and novel areas of climatic suitability may be crucial for long-term persistence and conservation of epiphytic orchids. Our study provides the first estimation of the potential distribution of epiphytic orchids in the Congo Basin and may be informative for regional conservation efforts across the Guineo-Congolian landscape.