Agroforestry's potential to buffer climate change impacts on maize yields in Dodoma, Tanzania

Agricultural productivity in the semi-arid region of central Tanzania is low and projected to further decrease due to climate change, exacerbating the already high levels of food insecurity among the population of Tanzania. Agroforestry has been suggested as an adaptation strategy due to its multiple biophysical and socio-economic benefits, but its effectiveness is site- and context specific. Therefore, the objective of this study was to investigate the impact of climate change and agroforestry on maize yields in Dodoma, Tanzania. The process-based crop model APSIMX is used to quantify climate change impacts on maize yields at six sites in Dodoma considering different shared socio-economic pathways and periods. In addition, the effects of different levels of shading, temperature reductions from shading and the addition of biomass from trees on maize yields were analyzed. Four different indicators (climate change impact, agroforestry impact, agroforestry adaptation effect and climate change impact with adaptation) were calculated to provide a comprehensive evaluation. The simulation results indicate that climate change is likely to decrease maize yields by 23–33%, but agroforestry is found to partially mitigate this decline. The benefits of implementing agroforestry will increase in the future, providing a positive adaptation effect. A shading level of 20% was found to be most effective at reducing yield losses. However, under the high-emission scenario, the effectiveness of agroforestry in mitigating climate change impacts is simulated to decrease over time. These results highlight the urgency of climate change adaptation and demonstrate the possible benefits but also the limitations of agroforestry as an adaptation strategy under present and future climate conditions.