Carbon storage, climate resilience, and livelihoods in coffee agroforestry systems: a systematic review

Coffee agroforestry systems (CAFS) are increasingly promoted as climate-smart land uses because they can store carbon while supporting adaptation and rural livelihoods. However, evidence remains fragmented across carbon pools, system designs, and outcome domains. This systematic review synthesised evidence on carbon storage and sequestration in CAFS and assessed how carbon outcomes relate to agroforestry structure, climate resilience, productivity, and livelihoods. Following PRISMA 2020 procedures, 46 peer-reviewed studies published between 2006 and 2025 were reviewed using structured qualitative and semi-quantitative evidence-strength synthesis. The review examined carbon pool assessment, the influence of shade, species composition, structural complexity, and management, interactions with climate-related stressors, and tradeoffs or synergies with productivity and livelihoods. Aboveground biomass carbon and soil organic carbon (SOC) were the most frequently assessed pools, although SOC was often the largest component of total system carbon. Carbon stocks were generally higher in systems with moderate to high shade, greater structural complexity, and lower management intensity, whereas simplification through shade removal or monoculture conversion reduced carbon storage. Species composition was important, but tree size, functional traits, and basal area were stronger predictors of carbon storage than species richness alone. Carbon-rich systems were frequently associated with resilience-supporting mechanisms, including microclimate buffering, soil protection, moisture retention, and post-disturbance recovery. However, direct evidence linking measured carbon stocks to specific climate-stress responses or livelihood outcomes remains limited. Overall, CAFS can contribute to climate mitigation, adaptation, and livelihood resilience, but their performance depends on ecological, management, and socioeconomic context.