Fruit tree-based agroforestry mitigates woody carbon losses under climate and land-use pressures in sub-Saharan Africa

Protecting carbon stocks in terrestrial ecosystems is a key strategy for climate change mitigation. However, these stocks are increasingly threatened by the combined and potentially interactive pressures of climate change and land-use intensification, complicating predictions of future carbon storage. In sub-Saharan Africa, farmers often retain or promote trees on their fields – particularly fruit-bearing species – potentially enhancing on-farm carbon stocks compared to treeless fields. Yet, the contribution of such farmer-led agroforestry practices to woody carbon storage in African drylands, especially under changing climate conditions, remains poorly quantified. We address this gap using large empirical dataset, harmonizing plot-level dendrometric data from multiple studies across West Africa and linking them to environmental variables. Using crossed space-for-time substitution approach and both ANOVA and Generalized Additive Mixed Models, we quantified the effects of aridity, land use, and other drivers on woody carbon stocks, and assessed how aridity and land use shaped carbon storage in fruit vs. non-fruit trees. Woody carbon stocks in near-natural vegetation decreased from humid to semi-arid zones ( 89%), with a threshold near the transition to dryland conditions. Conversion to cropland further reduced woody carbon, with the steepest losses in humid zones (-98%) and more moderate declines in semi-arid zones (-56%). Among environmental predictors, aridity explained 40.2% of the variance in woody carbon, followed by mean annual-burned area in interaction with land use and soil properties. Notably, fruit trees were more prevalent and stored more carbon in dryland croplands, reflecting farmer-led agroforestry practices that buffer climate risks and reduce carbon losses. Our findings highlight the vulnerability of woody carbon under future climate and land-use trajectories and the potential of locally grounded agroforestry, especially the conservation and planting of fruit trees, to reconcile ...