Regional Land–Atmosphere Interactions in Southern Africa: Potential Impact and Sensitivity of Forest and Plantation Change

Southern Africa is experiencing increasing land transformation and natural vegetation losses. Deforestation is one type of this land degradation where there are indigenous forests present, and afforestation of other nature ecosystems with timber plantations. This study performs regional coupled land–atmosphere model simulations using the Weather Research and Forecast (WRF) model with a resolution of 12 km, to assess the impact of forest and plantation cover change on regional climate in southern Africa. Three WRF simulations were designed for different land covers: (i) MODIS-derived land cover for the year 2000 (baseline), (ii) Landsat-based forest and plantation change map during 2000–2015 overlain on the baseline and (iii) theoretical forest and plantations removal relative to the baseline. Modeling results suggest that conversion of forest and plantations landscape to croplands and sparse vegetated land may result in a warmer and drier local climate, increasing daytime temperature by up to 0.6°C during the austral summer, and regulation of energy exchanges by decreasing the latent heat flux. In addition, results suggest that the removal of forest cover in northern part of southern Africa may decrease local precipitation recycling by around 1.2%. While the benefits of conserving native forests are obvious from an ecological perspective, afforestation considerations still require more detailed and local-scale treatments along the soil–vegetation–atmosphere continuum.