Effect of agroforestry shading on Robusta coffee (Coffea canephora) suitability under climate change in Uganda
摘要
Rising temperatures associated with climate change are expected to alter the suitability of coffee growing regions, yet the effectiveness of agroforestry as a climate adaptation strategy is insufficiently understood. This study assessed the potential of coffee agroforestry systems (CAFS) to moderate microclimate in Coffea canephora systems in Uganda by: (1) modelling current climatic suitability; (2) projecting future suitability under climate change scenarios; and (3) evaluating the influence of agroforestry-mediated thermal buffering on future suitability patterns. Future projections were generated under SSP2–4.5 and SSP5–8.5 climate warming scenarios, while agroforestry effects were simulated by reducing maximum temperatures by 3 °C and increasing minimum temperatures by 1 °C. Baseline suitability was first modelled under no agroforestry before applying agroforestry adjustments. Current suitability was classified as very high (6%), high (16%), moderate (23%), low (35%), and very low (20%), with precipitation of the warmest quarter (32.2%) and soil type (20.3%) as the dominant predictors of suitability. Without agroforestry, suitability declined under SSP5–8.5, with areas of very low suitability expanding to 49.4% and those of very high suitability declining to 0.8%. The relative buffering effect was greater under SSP2–4.5 (+ 38.2%) than under SSP5–8.5 (+ 17.2%), indicating that microclimatic buffering by agroforestry is more effective under moderate compared to extreme warming. These findings suggest that agroforestry may partially buffer coffee against rising thermal stress, but its effectiveness remains strongly influenced by precipitation and soil conditions. Consequently, climate adaptation strategies should integrate agroforestry with complementary water and soil management approaches to enhance long-term coffee resilience.