Climate Change Impacts on Agroforestry Suitability in the Amazon: CMIP6-Based Projections for Theobroma grandiflorum

Climate change is expected to significantly alter surface air temperature and precipitation regimes across the Amazon Basin, with direct implications for agroforestry systems and climate-sensitive perennial crops. This study projects the impacts of anthropogenic global warming on the habitat suitability of Theobroma grandiflorum (cupuaçu), a keystone species for Amazonian agroforestry, local livelihoods, and the bioeconomy. Using an ensemble species distribution modeling (SDM) framework, we applied multiple algorithms and two CMIP6 global climate models (BCC-CSM2-MR and MIROC6) under the SSP3-7.0 and SSP5-8.5 scenarios for the near-future (2021–2040) and far-future (2061–2080). Contrary to the range contractions projected for many Amazonian endemics, our ensemble projections reveal a consistent trend of expanding climatically suitable area, primarily into adjacent ecological transition zones. This expansion is driven largely by basin-wide increases in mean annual temperature, the most influential predictor in our modeling study. Quantitatively, we project a net habitat expansion of 32.2% (415,114 km2) under high-concordance future scenarios. A core climate refuge of 955,570 km2, representing 74.2% of the current suitable range, is identified as a high priority for in situ conservation. Conversely, approximately 25.8% of the current range (331,919 km2) may become climatically unsuitable, particularly in parts of the western Amazon. These findings suggest that reducing thermal constraints in currently marginal areas could open opportunities for integrating cupuaçu into climate-resilient agroforestry systems beyond its present distribution. Such heterogeneous responses of Amazonian agroforestry species to climate change highlight the importance of incorporating species-specific climate sensitivities into adaptation planning, land-use strategies, and climate-resilient bioeconomy policies under future warming scenarios.