The first draft of the literature review has been submitted and I depart for Hanoi tomorrow. Since the last post I have been starting to look at carbon stocks and flows on cocoa farms and the following are some key points from what I have been reading.
Carbon stocks on-farm contribute to cocoa farming’s potential for mitigation of greenhouse gas emissions. In order to assess the carbon sequestration and mitigation potential, the carbon stock on farm must be estimated. The carbon stock of the farm is the total carbon stored in the system, including in the cocoa trees, shade trees, soil organic carbon (SOC) and soil litter. SOC is normally the largest contributor to the total carbon stock. In Sulawesi for example, a study found that SOC contributed 55% to the total carbon stock, followed by 22% from shade trees, 12% from cacao trees, 8% from roots, and 8% from soil litter (1), see figure below.
Above ground carbon stock includes contributions from cacao trees, shade trees, and any native vegetation. Shade trees contribute the most to the above ground carbon stock. In the same above example in Sulawesi, shade trees contribute nearly three times what cocoa trees contribute (22% versus 8% of the total carbon stock).
The density of shade trees on a cocoa farm also affect the carbon stock. An example from a forest reserve in Nigeria which compared the above-ground carbon storage in a protected primary forest against both sparse and dense cocoa agroforests, found that the primary forest had the largest values for carbon stock and above ground biomass and the sparse agroforest had the lowest (2), see figure below.
References:
- Swisscontact, 2016, Carbon Stock and Carbon Footprint in the Indonesian Cocoa Sector Sustainable Cocoa Production Program SCPP, Jakarta.
- Oke and A. Olatiilu, “Carbon Storage in Agroecosystems: A Case Study of the Cocoa Based Agroforestry in Ogbese Forest Reserve, Ekiti State, Nigeria,” Journal of Environmental Protection, Vol. 2 No. 8, 2011, pp. 1069-1075