Influence of tree cover on diversity, carbon sequestration and productivity of cocoa systems in the Ecuadorian Amazon

Abstract

Cocoa production in the Ecuadorian Amazon is an important source of income for the local population. There is a wide variety of cocoa production systems, from enriched primary forests to traditional agroforestry systems and monoculture. This study assesses the relationship between tree diversity, carbon stocks, agricultural productivity and forest use potential under three land use systems in the Ecuadorian Amazon: cocoa-based agroforestry (Cocoa AFS), cocoa monoculture (Monoculture) and primary forest (PF). Understanding and quantifying the tradeoffs between different ecosystem services related to cocoa production systems can contribute to the conservation of primary forests and help to optimize income for local people. Species richness, beta-diversity, carbon stocks (above- and below-ground biomass, necromass and soil), and cocoa and timber production were determined for each system in 1,600 m2 study plots (n=28). The results show that beta diversity, species richness and carbon stocks were significantly higher in PF and Cocoa AFS, whereas cocoa production was 1.5 times higher in the Monoculture than in Cocoa AFS. In both cocoa systems, species richness, beta diversity and total C were negatively correlated with cocoa productivity. Although our results show that cocoa monoculture was more profitable than Cocoa AFS for the farmers, a monetary payment based on carbon credits for avoided deforestation could be a viable strategy to support the implementation of Cocoa AFS, which would help conservation efforts and climate change mitigation while sustaining commercial cocoa production in the area.