Predicted impacts of global climate change on the geographic distribution of an invaluable African medicinal plant resource, Alstonia boonei De Wild

Abstract

The likely effects of climate change on geographic distributions of African medicinal plants have not seen detailed analysis. We investigated likely effects of future climate change processes on suitable geographic areas for an important medicinal plant resource, Alstonia boonei De Wild. We characterized the potential geographic distribution of the species by means of ecological niche models based on primary biodiversity data and interpolated climate data from the WorldClim archive. Results indicated that suitability for the species was lower at the northern and southern extremes of the species’ known geographic distribution, whereas broader areas in the eastern half of the species’ distribution were identified as suitable. Future potential geographic distributions were similar to present-day distributional patterns, with modest increases in suitability, which translated into only subtle likely range shifts, with slight expansions of suitability for the species in all directions. As such, in the face of changing climate, the geographic distribution of Alstonia boonei is likely to remain largely stable under present and future climates. This study serves as an example of how ecological niche modeling can be used to evaluate probable effects of future climate change on invaluable natural medicinal resources, implications for healthcare, livelihoods, and conservation practice.