Cocoa farming and biodiversity in Ghana
Cocoa trees (Theobroma cacao) are small trees originally native to the Americas but which are now widely farmed in Western Africa. These are harvested for their beans, which go through various stages of treatment to provide us with the tasty chocolate treats we love to munch on during the Yuletide season. A significant part of the world's cocoa is produced in Ghana, where an Earthwatch project studying cocoa farming impacts on biodiversity has recently come to the end of its first phase.
Cocoa farming accounts for about 40 per cent of Ghana's total exports, and is a major source of livelihood to the country's rural communities. The government of Ghana has prioritised cocoa as a commodity crop and aims to increase future production. However, the sustainability of current cocoa farming practices that focus on obtaining high yields from intensely managed farms is often questioned, since these unshaded cocoa farms are established in deforested areas and contain virtually no other tree species. Shaded cocoa farms, where other native tree species provide a dense canopy for cocoa trees, are thought to offer a more environmentally sound alternative to unshaded farms.
Earthwatch initiated a three year field research project in 2005 with Cadbury to study the biodiversity and soil health impacts of cocoa farming. Another key partner in this project was the Nature Conservation Research Centre (NCRC), with whom Earthwatch has collaborated since 2000 on several Ghana-based projects. Other partners include the Cocoa Research Institute of Ghana (CRIG) and Reading University. The research was led by Dr. Kwasi Ofori-Frimpong (CRIG) and Dr. Alex Asase, who were assisted in their data collection by field research teams composed of Cadbury employees and local university students.
The research was carried out between 2006 and 2008 in Adjeikrom, in the eastern region of Ghana, and consisted of collecting data on cocoa tree productivity, nutrient cycling* and biodiversity levels along a gradient from native forest without cocoa trees, to extensively shaded cocoa farms, through to intensively managed unshaded cocoa farms.
Research teams studied biodiversity levels along the gradient by sampling various species of plants, animals, and insects. Nutrient cycling was investigated by collecting cocoa litter (dead plant material that has fallen to the ground such as leaves and twigs) and soil samples which were analysed in the lab to determine litter decomposition rates and soil acidity along the gradient. The productivity of cocoa trees in different plots was also recorded.
The results from the first phase of the project indicate that there are clear differences between shaded and unshaded cocoa farms. Productivity was considerably higher on unshaded farms owing to a higher density of cocoa trees. Retaining shade was found to have a positive impact on biodiversity, as biodiversity levels decreased with increasing yield in the unshaded farms (although the impact varied between biodiversity groups). Shaded cocoa farms were found to have faster litter decomposition rates and higher soil nutrient contents, and less acidic soils than unshaded farms, indicating more effective nutrient cycling.
The results of this study show that despite their lower overall productivity, shaded cocoa farms are conducive to more efficient nutrient cycling, increased litter fall, high nutrient contents, and higher biodiversity levels than unshaded farms, indicating it may be considered a more sustainable solution to cocoa farming in the long term.
Another outcome of this project has been the development of the first cocoa farming ecotourism facilities to supplement rural communities' income. These facilities were launched in Adjeikrom in March 2008 and will introduce visitors to Ghana's cocoa industry and showcase the benefits of environmentally friendly cocoa farming.
This project has yielded good results that improve our understanding of the sustainability of cocoa cultivation and its impacts on biodiversity. These results will be used to make recommendations for increasing the number of sustainably managed farms in the project area that can generate both biodiversity benefits and ensure sustainable livelihoods. The next phase of the project will build upon these findings and also assess the carbon storage capacity of traditional cocoa farms to determine whether this carbon can be sold as credits to supplement farmers' income and encourage sustainability.
Did you know?
Most of the cocoa grown in Africa is of the Forastero variety, which accounts for 80-90 per cent of global production. The other two varieties of cocoa beans, Criollo and Trinitario, are grown mainly in Central and South America, and provide a more complex flavour which is ideal for darker chocolates.
*Nutrient cycling: a process where plant tissues are broken down upon decomposition to release nutrients that then become available for uptake by other organisms.
Read about Earthwatch's partnership with Cadbury.
Find out more about the cocoa farm tourism initiative.
World Cocoa Foundation