two hectares (Nagayets, 2005). In other countries such as Lesotho, D.R. Congo and Ethiopia, the area per household is decreasing (Nagayets, 2005), making it increasingly difficult for individual farm households to commercialize. If land holdings begin to consolidate, understanding and dealing with increased rural unemployment and rural-urban migration will become particularly important.

5.6 Crop and Livestock Diversity
Two types of agricultural biodiversity are identified by the Convention on Biological Diversity (CBD): a managed portion that is manipulated by people for their own needs; and an unmanaged portion such as soil microbes, natural enemies, pollinators and their food plants that supports production (Biodiversity International, 2007). Farmers naturally play a role in conserving agricultural biodiversity, a role that can be exploited and incorporated into more formal conservation approaches. However, there is a general consensus that agricultural intensification has been accompanied by decreasing agricultural biodiversity. Industrialized agriculture has tended to promote a small number of species, and scientific research has typically been focused on these species (FAO, 2002; MA, 2005), resulting in a decline in genetic diversity for agricultural crops.

Genetic erosion of indigenous germplasm for both forage and livestock species is increasing in SSA. This is of particular concern for the region because many countries have a wide range of crops that are considered relatively unimportant on a global level, but are important as local staples (Engels et al., 2002). Further, over 95% of Africa’s ruminant population is indigenous, supporting the majority of small-holder rural farmers for whom these genetic resources are critical as a source of food, income and secure form of investment. The causes of this genetic erosion include human population growth, increased pressure for land development, urbanization, climate change and controlled breeding and development of livestock breeds with a narrow genetic base to meet the demands of modern production systems. There also appears to be a loss of local and traditional knowledge concerning species diversity, including loss of local language terms, in part a natural consequence of changes in cropping systems.

There are two key linked responses for conserving agricultural biodiversity, as identified by the Millennium Ecosystem Assessment and recognized elsewhere: in situ conservation (conservation of important genetic resources in wild populations in natural habitats, whether farmer fields or within existing agroecosystems), and ex situ conservation (conservation of genetic resources in off-site gene banks).

5.6.1 Safeguarding and maximizing potential of genetic resources
Changing climatic conditions, the importance of livestock in SSA, clonal propagation and the high costs of ex situ conservation suggest an emphasis on in situ conservation to be most appropriate for SSA. In situ conservation is essential for conserving animal genetic resources, and most relevant for hard to store tropical species and for those that are clonally
propagated, and therefore particularly relevant to SSA. It also helps maintain evolutionary processes (preserving the process of crop evolution) and may have a positive impact

on equity (Brush, 1992; Jarvis et al., 2000; Meilleur and Hodgkin, 2004; FAO, 2007a).

Although ex situ collections substitute imperfectly for the evolution of crops on farmers’ fields, storing genetic resources as back-up seed stocks in ex situ collections is a key element of conserving genetic diversity (Drucker, 2005). However, ex situ collections are costly, involve considerable losses, and—due to climate change or genetic drift—genetic resources held in long-term storage may no longer be suitable for cultivation in the areas where they were collected (Biodiversity International, 2007). Specific challenges for Africa include the difficulty of storing many tropical seed species (Pardey et al., 1999), and that many crop plants are clonally propagated.

Additional issues include how to ensure sufficient longterm and reliable funding; how to ensure sharing (in particular with IPR issues and the involvement of the private sector); and how to ensure that biodiversity being protected today is relevant to predicted climate changes (for example, drought-resistant varieties are likely to be more important in many parts of SSA in an environment of climate change). Genetic resources have public good characteristics—farmers who cultivate crops and keep livestock with valuable genetic traits do not reap the full benefits of their conservation efforts, suggesting that the private on-farm provision of genetic resources will typically be lower than optimal (Brush, 1992) and hence there is a role for government.

Governments can intervene in genetic conservation in a number of ways that include setting up protected areas where human activity is excluded or limited; subsidies to particular agricultural sectors or direct payments to farmers; empowering villagers to conserve species diversity at the community level, such as in community forests; and developing markets and creating market incentives. These interventions can broadly be divided into market and nonmarket interventions and each has different implications for funding and sustainability of that funding. Subsidies for particular sectors or direct payments to farmers do not naturally respond to evolutionary changes and are susceptible to rent seeking behavior and so are not considered further in this assessment. Protected area systems that exclude human activities have been established throughout many countries in SSA, although the reality of many is that they are simply “paper parks,” where little enforcement occurs due to lack of funding and so degradation and loss of diversity is prevalent. Yet, where protected areas are effective at keeping out people, nearby communities are often harmed as they tend to rely on common areas of land, particularly forests, for nutrition and livelihood activities.

Working with local communities is essential to conserve biodiversity in the longer term (MA, 2005). A number of prerequisites are required for in situ conservation, particularly with respect to common pool resources (such as village-level forests). Well-defined property rights in favor of local villagers (land tenure security), or at the least legal recognition of the villagers as forest managers, are a pre-requisite for getting villagers to participate in protecting the nearby village forests and hence the genetic diversity contained within the forests (Wiley, 1997; Wiley et al., 2000). Participatory rural appraisals can help decision makers and local communities with communally owned land to determine their own pri-