Impacts of climate change on the geographic distribution of African oak tree (Afzelia africana Sm.) in Burkina Faso, West Africa

Larba Hubert Balima; Blandine Marie Ivette Nacoulma; Sié Sylvestre Da; Amadé Ouédraogo; Dodiomon Soro; Adjima Thiombiano

doi:10.1016/j.heliyon.2021.e08688

Impacts of climate change on the geographic distribution of African oak tree (Afzelia africana Sm.) in Burkina Faso, West Africa

Heliyon. 2021 Dec 29;8(1):e08688. doi: 10.1016/j.heliyon.2021.e08688. eCollection 2022 Jan.

Authors

Larba Hubert Balima^{1

2}, Blandine Marie Ivette Nacoulma², Sié Sylvestre Da³, Amadé Ouédraogo², Dodiomon Soro¹, Adjima Thiombiano²

Affiliations

¹ WASCAL Graduate Research Program on Climate Change and Biodiversity, University Félix Houphouët-Boigny, 31 Po Box 165, Abidjan 31, Côte d'Ivoire.
² Laboratory of Plant Biology and Ecology, 03 Po Box 7021, Ouagadougou 03, Burkina Faso.
³ WASCAL Competence Center, 06 Box 9507, Ouagadougou 06, Burkina Faso.

Abstract

Afzelia africana Sm - a multipurpose leguminous tree species - is threatened in West Africa - a climate change hotspot region. Yet, although the impacts of land use on this species dynamics have been widely reported, there is a little literature on the impacts of climate change on its spatial distribution. This study aimed to predict the impacts of climate change on the geographic distribution of A. africana in Burkina Faso. A total of 4,066 records of A. africana was compiled from personal fieldwork and vegetation database. Current and future bioclimatic variables were obtained from WorldClim website. For future climatic projections, six global climate models (GCMs) were selected under two emission scenarios (RCP 4.5 & RCP 8.5) and two horizons (2050 & 2070). Presence data and bioclimatic variables were processed in ArcGIS software and used in the algorithm MaxEnt (maximum of entropy) to predict the species distribution. Findings showed that maximum temperature of warmest month and mean temperature of coldest quarter mostly affect the habitat suitability of A. africana. About 25.54% of Burkina Faso land surface was currently suitable for A. africana conservation. Under future climatic projections, all the climate models predict climate-driven habitat loss of the species with a southward range shift. Across the two emission scenarios, the spatial extent of suitable habitats was predicted to decline from 9.43 to 23.99% and from 12.29 to 25% by the horizons 2050 and 2070, respectively. Habitat loss and range shifts predicted in this study underline the high vulnerability of A. africana to future climate change. Reforestation actions and the protection of predicted suitable habitats are recommended to sustain the species conservation.

Keywords: Climate change; Distribution modelling; Habitat suitability; Threatened species; West African Sahel.