Enhancing agroforestry systems through tree domestication
The domestication of trees is essential to enhance the products and services provided by agroforestry systems1. A range of domestication methods has been developed over recent decades. These methods are context specific and include a participatory domestication approach involving scientists and farmers working in close collaboration. This approach has had positive impacts on incomes, diets and in rural business development. However, to be more widely successful, agroforestry tree domestication still requires greater attention to scaling-up approaches, working with a wide range of partners in different partnership models. Future domestication work will also require more specific consideration of a wider range of traits related to ecosystem services’ provision, with the appropriate mobilisation of genetic diversity.Enhancing product and service provision from trees to improve livelihoods, increase productivity, combat malnutrition and adapt to anthropogenic climate change2,3 involves their domestication — the genetic changes involved in bringing a plant into cultivation and in its continued development as a planted resource, through both unconscious and deliberate selection and breeding — to adapt them to meet human needs. The process of domestication began over 10,000 years ago for annual crops4, and a few millennia ago for selected food trees5,6,7,8, but the vast majority of the Earth’s > 80,000 tree species are still essentially wild or only incipient domesticates9. This chapter outlines approaches for tree domestication and the benefits realised, as well as some of the dangers involved, and concludes by exploring requirements for future work. In particular, it will explore the domestication of food trees to address the problems of food and nutritional security in Sub-Saharan Africa10. Many of the world’s nations with the highest burden of child under-nutrition are found in the region and, in particular, the consumption of fruit and healthier (non-starchy) leafy vegetables is overall well below global averages11. Conversely, a wide range of trees producing foods rich in micronutrients, fibre and protein is located in the region, which could support enhanced, biodiversity-based food solutions12.