ECOLIMITS is an interdisciplinary, Ecosystem Services for Poverty Alleviation (ESPA) funded project exploring the ecological limits of ecosystem system services (ESS) for supporting small-scale production of cocoa (Theobroma cacoa) in Ghana. We began collecting data in mid-2014 and have captured yield measures for a relatively representative year and a crop cycle severely impacted by the 2015/16 El Nino. To assess landscape and on-farm management factors affecting ESS and crop yields in Ghana, we established 36 plots in a cocoa landscape along a forest-distance gradient from Kakum National Park as well as three forest monitoring plots. The ESS we collected were net primary productivity (NPP), above-ground and below-ground carbon, biodiversity (both conservation and functional values), soil fertility, nutrient cycling, micro-climate, pollination and pest control. We sampled monthly cocoa disease and fruitset variables in each cocoa plot, while ten plots were intensively sampled for NPP components. We also surveyed our study farmers to establish the intensity of their farm management in order to assess the contribution of ESS and labour/chemical inputs to crop yields.
Results/Conclusions
We developed a yield model to compare the most influential ESS on cocoa yields and identified the factors that farmers would have the ability to manipulate. We found that only two factors, number of fertiliser applications per year and maintaining rotting biomass in the farms were available for farmers to modify. Otherwise, factors such as landscape location (e.g. distance from intact forest) and shade level are largely socially mediated and not available to farmers to easily modify. Regardless, we found that yield improvements at the farm level were not as important to livelihoods as social factors such as farm size, land tenure arrangements and rent payments indicating that efforts to maximize yields through managing ESS will have limited impact on poverty alleviation.