Future climate suitability of shade trees in cocoa agroforestry systems in West Africa and shade tree diversity’s impact on farm microclimate : A Minor Field Study

Abstract: Shade trees’ implementation into cocoa agroforestry systems in tropical West Africa has proven to have a high potential in increasing farm resilience and mitigating climate change. However, no studies have yet examined the potential future climate suitability for shade trees in the region, which is important when deciding which shade trees to implement. The aim of this study was to predict the current and future climate suitability of shade trees currently used in cocoa agroforestry systems and give recommendations based on the results. It also aimed to examine how different levels of shadetree diversity can impact a farm’s microclimate and how this can be linked to climate suitability for cocoa. To assess climate suitability, a species distribution model was performed for a baseline scenario with the current climate defined as 1970-2000 and for two future scenarios, SSP126 and SSP585, for the time period 2041-2060. To measure microclimate, a microclimatic study was performed in the Ashanti region of Ghana on 16 farms during mid March to mid May 2023 measuring the maximum temperature above cocoa canopy and 15 cm above the ground for three different treatments. The results showed that three species, Khaya senegalensis, Ceiba pentandra and Albiziazygia, were predicted to have the largest habitat areas of climate suitability in West Africa for several of the scenarios. However, it was also identified that the model could be improved when it comes tothe inclusion of more bioclimatic variables, global circulation models (GCMs) and for which futures cenarios to model for. The microclimatic study showed that both farms with a low and high level of shade tree diversity have a significant possibility to buffer the maximum temperature above cocoa canopy, with low diversity farms having a larger buffering capacity. The study also showed that areaswhere several shade tree species are predicted to have a climatically suitable habitat decreased for future scenarios, which could be a risk for the possibility to mitigate climate change for cocoa with shade tree implementation in the future.