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Previous research indicates that some important cocoa cultivated areas in West Africa will become unsuitable for growing cocoa in the next decades. However, it is not clear if this change will be mirrored by the shade tree species that could be used in cocoa-based agroforestry systems (C-AFS). We characterized current and future patterns of habitat suitability for 38 tree species (including cocoa), using a consensus method for species distribution modelling considering for the first time climatic and soil variables. The models projected an increase of up to 6% of the potential suitable area for cocoa by 2060 compared to its current suitable area in West Africa. Furthermore, the suitable area was highly reduced (14.5%) once considering only available land-use not contributing to deforestation. Regarding shade trees, 50% of the 37 shade tree species modelled will experience a decrease in geographic rate extent by 2040 in West Africa, and 60% by 2060. Hotspots of shade tree species richness overlap the current core cocoa production areas in Ghana and Côte d'Ivoire, suggesting a potential mismatch for the outer areas in West Africa. Our results highlight the importance of transforming cocoa-based agroforestry systems by changing shade tree species composition to adapt this production systems for future climate conditions. [ABSTRACT FROM AUTHOR]

Establishment of a tree canopy in Cocoa Agroforestry Systems (C-AFS) provides higher carbon stocks and other ecosystem services compared with other agricultural land uses. These systems are eligible for incentive schemes for carbon sequestration but need to be optimally designed to ensure that they meet intended future goals. In this study, we combined environmental-dependent growth models and allometric equations to forecast carbon sequestration in an innovative C-AFS trial in Côte d'Ivoire and compare the results with values estimated in other cocoa systems elsewhere. The polynomial regression and non-linear regression models provided the best fit models to predict total height and stem diameter in cocoa and associated shade tree species. Then, best species-specific allometric equations were selected and used to estimate biomass from stem diameter and/or tree height. Carbon stock in the trial ranged from 37.2 to 40.5 Mg C ha−1 at 20 years, with abrupt changes due to the management activities during the study period. Timber trees stored more than 45% of aboveground carbon stocks across all agroforestry schemes. The models developed in this study hold clear applications and will serve as major platforms to design new cocoa agroforestry systems and make well-informed management decisions to maximize carbon sequestration. [ABSTRACT FROM AUTHOR]

The expansion of cocoa farming has been linked to deforestation and biodiversity loss in West Africa. Agroforestry systems could potentially increase the sustainability of cocoa production. However, despite the long history of cocoa cultivation in agroforestry systems, the exact mechanism or the combination of factors that drive cocoa growth and yield in these agroecosystems, especially at the cocoa establishment stage, is unclear. The present study aims to analyse how resource availability, stand characteristics and cocoa tree morphology interact to determine the performance of cocoa during the establishment phase among different cocoa cultivation systems. We studied seven different agroforestry systems and one monoculture system in 53 plots located in a 12-ha cocoa agroforestry trial recently established in Côte d'Ivoire. We characterized each system with 16 variables that described five system components: 1) cocoa yield (number of pods, pods weight, number of productive trees) and cocoa growth (basal diameter), 2) cocoa tree morphology (crown depth, diameter, area, and volume), 3) stand characteristics (number and size of shade trees), 4) light (leaf area index) and 5) water (soil volumetric water content). We used a Structural Equation Modelling (SEM) approach to understand and quantify interactions between the five components. The models were able to largely explain cocoa early yield and juvenile growth variability (respective determination coefficients: 0.45 and 0.92). We observed improved cocoa establishment in certain designs of agroforestry systems compared with monoculture. However, SEM revealed that stand characteristics (i.e. increase in the number and height of shade trees) had a negative effect on cocoa yield and growth via changes in cocoa tree morphology, having path coefficients of −0.48 and − 0.72, respectively. Conversely, we found a positive relationship between the cocoa tree morphology and cocoa early yield, for which the path coefficient was 0.74, the strongest relation. Cocoa tree morphology was more important than stand characteristics, leaf area index, and soil volumetric water content in controlling cocoa yield and growth. Taken together, our results suggest a competition for space between shade trees and cocoa plants. Finding the optimal design of agroforestry systems can help enhance cocoa establishment in the first years, improving the long-term performance of the system. This finding suggests that the competition effect depends on spatial planting pattern and species composition, offering an opportunity to meet the goals of a sustainable intensification of cocoa plantations through the design and management of optimal agroforestry systems. [Display omitted] • Cocoa yield and growth in the establishment phase are the result of interactions between the stand characteristics and cocoa crown development. • The competition for space in dense systems make the benefits of shade trees relatively unimportant. • Adequate agroforests design and management can enhance cocoa early yield and growth via an enhancement of crown development. [ABSTRACT FROM AUTHOR]