Climate change mitigation in agroforestry systems: linking smallholders to forest carbon markets BAMBI L . SEMROC , GÖTZ SCHROTH , CELIA A . HARVEY ,
Smallholder agricultural producers manage vast areas of land that could store or sequester important carbon stocks when managed under agroforestry systems. However, the potential for smallholder production systems to contribute to climate change abatement has not been adequately incorporated into the design of international or national policies addressing climate change (Montagnini and Nair 2004). Agroforestry systems intentionally integrate tree cultivation with agricultural crops, pastures or livestock production (Harvey et al. 2008). Smallholders with less than two hectares of land under production account for an estimated 85% of farms globally (Nagayets 2005). Zomer et al. (2009) estimated that between 17% and 46% of all agricultural land contains some degree of tree cover and more than 1 billion hectares of land have at least 10% tree cover. The majority of these lands are located in South America, sub-Saharan Africa and Southeast Asia and are managed by smallholder producers (Zomer et al. 2009). These systems, managed appropriately, have the potential to maintain important stocks of carbon and may present opportunities for additional carbon sequestration (Trexler and Haugen 1994; Brown et al. 1996; Bloomfield and Pearson 2000; Cacho et al. 2003), which could deliver important climate benefits while simultaneously contributing to poverty reduction. Forest carbon projects tend to fit into two categories: afforestation/reforestation (A/R) (the planting of trees in areas with no current forest cover);
and reducing emissions from deforestation or forest degradation, commonly referred to as REDD+.1 Opportunities exist for smallholder agroforestry systems to contribute to both types of mitigation activities. Farmers may increase tree cover on their land through the introduction of agroforestry practices within productive areas, for example by introducing shade cover within sun coffee plantations and by increasing and diversifying tree cover within existing agroforestry systems (Smith and Scherr 2002). Under a REDD+ mechanism, agroforestry systems can serve as the carbon stock to be protected, or they can be promoted on existing cropland to reduce the need to deforest new lands to maintain or increase productivity, thereby reducing pressures within a broader landscape (Phelps et al. 2010). In the first case, the forested areas of the agroforestry system may be protected from conversion to competing, lower-carbon land uses if coupled with incentives commensurate to the opportunity cost of conserving them. In the second case, agroforestry could serve to enhance the productivity of existing farms and diversify livelihoods, thereby diminishing pressures for expansion of less productive practices into remaining forests. Farmers can also increase the density of shade cover within existing agroforestry systems as a means of carbon stock enhancement under REDD+ (Phelps et al. 2010; see also chapter by Méndez et al.). A third opportunity is avoiding the degradation of agroforestry systems (e.g., the gradual conversion of shade-grown coffee through timber extraction) and thereby reducing greenhouse gas (GHG) emissions. Further opportunities for climate change mitigation through agroforestry systems include the adoption of agricultural practices that reduce GHG emissions, either by reducing the need for fertilizer application or maintaining or enhancing the amount of carbon stored in agricultural soils. Realizing the carbon mitigation potential of smallholder agroforestry systems requires a greater focus on putting into place the incentives necessary to enable smallholder participation in the developing carbon market. The projects presented in this chapter focus exclusively on the forest carbon potential of agroforestry systems, recognizing that additional GHG emission reductions could be generated through the integration of agricultural carbon initiatives. The three projects featured in this chapter apply a variety of approaches and standards. Two focus on forest restoration while the third explores the feasibility of introducing REDD+ among smallholder coffee producers (see also global review of smallholder coffee agroforestry by Méndez et al.). Each project is applying different carbon accounting standards and using different mechanisms for registering credits generated (Table 30.1).