ELLS Conference 2026

Agroforestry systems (AFS) are widely recognized for their greater carbon sequestration potential compared to monocultures; however, the extent to which this carbon is stabilized and retained over the long term, as well as the factors controlling its persistence, remains poorly understood. This study combines a global literature synthesis on carbon stocks in tropical cacao production systems with a field-validation framework to be implemented in the Coastal and Amazon regions of Ecuador. The research will evaluate two cacao production systems, monocultures and agroforestry systems (AFS), through the analysis of soil organic matter fractions (POM–mOM), stable isotopes (δ¹³C), remote sensing-derived vegetation indices (NDVI, EVI, and SAVI), edaphoclimatic variables, and agricultural management practices. Soil organic carbon (SOC) stocks and stable mineral-associated organic matter (mOM) will be quantified throughout soil profiles, while isotopic signatures will be used to trace the contributions of C₃ and C₄ vegetation to carbon inputs.
Preliminary global synthesis indicates that, although some high-density monocultures may exhibit elevated aboveground cacao biomass, agroforestry systems consistently store greater amounts of total carbon. Values of up to 101.39 Mg C ha⁻¹ in Ghana and 113.00 Mg C ha⁻¹ in Bolivia have been reported, largely driven by shade-tree canopies and increased deep-root turnover. Furthermore, δ¹³C isotopic evidence suggests that AFS accelerate the replacement of residual pasture-derived carbon with more stable, forest-like plant carbon. In Ecuador’s Amazon region, Chakra systems demonstrate remarkable carbon storage capacity, reaching up to 97.80 Mg C ha⁻¹ and recovering nearly 42% of the carbon stocks observed in secondary forests (233.00 Mg C ha⁻¹). Based on these findings, the field phase will investigate carbon stabilization mechanisms in Ecuadorian cacao systems. Field data will support predictive models integrating soil, vegetation, management, and remote-sensing variables to identify and map areas with the highest potential for long-term carbon sequestration and stabilization.