Elsevier

Ecological Indicators

Volume 8, Issue 2, March 2008, Pages 170-179
Ecological Indicators

Comparing the “Big Five”: A framework for the sustainable management of indigenous fruit trees in the drylands of East and Central Africa

https://doi.org/10.1016/j.ecolind.2006.11.009Get rights and content

Abstract

There are many fruit trees that could be integrated into dryland farming systems in Sub-Saharan Africa to support income and nutritional security. Fruit contains almost all known vitamins and many essential minerals. Five important fruit species that are cross-regional include: Adansonia digitata, Tamarindus indica, Zizyphus mauritiana, Sclerocarya birrea, and Mangifera indica. While these species are well integrated in the Sahel region, besides mango, they are generally absent from smallholder farms in East and Central Africa. Fruits of the species in this region are mostly harvested unsustainably from the wild communal areas. Unlike the situation in the neighboring Southern Africa region, where S. birrea is utilized extensively in the wine industry, there is virtually no use for the tree in this region, largely because of limited knowledge. Z. mauritiana use is also limited because of low quality germplasm—the hard stone clings to the flesh. An analytical framework based on five factors (site requirements, genetic variability, propagation methods, nutritional properties and utilization, and commercial potential) is used to compare knowledge status and gaps on the species in the region. While this analysis reveals the existence of considerable knowledge between and within the species, lack of improved germplasm and markets emerge as two key constraints limiting their conservation through on-farm planting. Key research and development needs identified are: (a) fostering cross-collaboration and knowledge exchange with other regions where the species are fairly well utilized, and (b) developing criteria and indicators for monitoring impacts and increased investments on the “Big Five” on livelihood of dryland communities and on biodiversity conservation.

Introduction

Food security and alleviation of poverty in rural communities in Africa can be improved by diversifying the farming systems (Leakey and Simons, 1998). Crop farming alone, without incorporating livestock production, horticulture, tree planting and embracing alternative livelihoods such as bee keeping, irrigated agriculture, indigenous fruits and marketing of non-wood products, would not improve the standard of living for farming communities in Africa (Sanchez, 1995). This is particularly important in the drylands of the East and Central Africa (ECA) region where frequent famine and droughts are increasing the incidence of hunger and poverty. Vast tracts of the ECA region are classified as drylands, with Kenya having the most, as a percentage of its land area.

Between cropping seasons, farmers in the drylands of the region rely on alternative food products that include trees, fruits, animals and sale of non-wood products to eke a living, especially during droughts (Muok et al., 2000, Chikamai et al., 2004). Farming with fruit trees, particularly mangoes, as an alternative source of food and nutritional security is increasingly becoming popular (Greisbach, 2003). Fruit contains almost all known vitamins and many essential minerals. Children and women are the major users of indigenous fruit trees (IFTs) which are mostly available in the dry seasons (Swai, 2005). Where commercialized exploitation of indigenous fruits occur, for example, in the west and southern Africa regions, indigenous fruits show great potential – as much as exotic fruits – in providing food, vitamins and income. In contrast, indigenous fruits have largely not been exploited commercially in the ECA region. This is in spite of the existence of a wide range of IFTs, including those present in the other dryland regions of Africa.

There is a considerable wealth of knowledge among farmers and rural communities on the value and uses of IFTs (Demel and Abeje, 2004). This knowledge has been used, to some extent, to prioritize species domestication and identify research and development needs (Muok et al., 2000). However, there is little planting of these trees, with the possible exception of mangoes. Most of what is used is collected from the wild. Unfortunately, many trees in the wild are being destroyed through processes such as charcoal production (an important economic product for many poor people) and expansion of agriculture (Maghembe, 1994). Studies by Mohamed (2005) in communal lands in eastern Kenya, for instance, found species density to be more abundant in sparsely populated areas due to less clearance from cultivation, fires and destruction of wildings by livestock. In Uganda, there is fear among farmers that fruits may attract birds that damage crops (Okullo, 2005). Existing legislature and taboos regulating the use of the trees are currently not adhered to and the knowledge of codified rules is disappearing with generational changes.

Reversing this situation requires integration of the IFTs into the farming systems of the area. At present, the observations of Leakey and Simons (1998) that inconsistency in product quality and limited access to markets are two key problems to commercialization of the non-timber forest products (NTFPs) holds true for the “Big Five” as well. Farmers typically do not plant indigenous trees but protect those that grow naturally for their own use (Muok et al., 2000). National tree seed centres often do not stock many indigenous species because, compared to the exotic species, there is little demand for them. This is a ‘catch-22’; farmers often plant only the tree seedlings available in local government or project tree nurseries rather than what they would have chosen. Also, there is limited extension materials developed from research on the IFTs (Muok et al., 2000). While the provision of improved germplasm may enhance the planting of IFTs, this must be accompanied by efforts to expand the markets so that farmers can increase returns from their investments (Cooper et al., 1996).

Priority setting exercises within the ECA region have identified a number of species in the drylands for domestication. Four species that typically are high are Sclerocarya birrea (marula), Tamarindus indica (tamarind), Adansonia digitata (baobab), and Zizyphus mauritiania (desert apple) (Chikamai et al., 2004). These species are keystone species in most landscapes of the drylands. In some areas, farmers protect them, especially if they have commercial value (Nyandoi, 2004). Besides these species, Mangifera indica (mango) is another key species on farmlands in the drylands. It has been naturalized in the region where it was introduced by Asian and Arab traders at the turn of the 19th century. Synthesis of knowledge on the five species, referred to as the “Big Five” in this paper, would provide insights for developing management options that enhance their conservation and contribution to food and the nutritional security of rural communities. This paper focuses on research and development efforts needed to get wide-scale planting, use and commercialization of the fruits and other non-timber products of the species.

A logical starting point is an analytical framework that helps assess the suitability of the species for use across the region. We do this by identifying the knowledge base and gaps for each species using five key factors of importance to producers and consumers: site requirements, genetic variability, propagation methods, nutritional properties and utilization, and commercial potential. We then highlight the extent to which the existing knowledge could be used to promote greater use of the species and identify critical gaps in the sustainable management of the species. The final section highlights the implications for research and development, taking into consideration the existing criteria and indicators proposed for sustainable forest management under the Dry-Zone Africa Initiative (Anon., 1999).

Section snippets

Approach

We used two approaches to determine the key factors that influence farmers’ decisions to invest in fruit trees: (a) review of literature, within and outside our region of interest, and (b) consultations with key stakeholders—farmers, and the research and development community during a regional workshop on agroforestry in the drylands of the ECA that was held at ICRAF in September 2004 (Kassim et al., 2005). This was followed by a second regional workshop (Simitu et al., 2005) at a local market

Sclerocarya birrea (A. Rich.) Hoscht

This is a dioecious multipurpose fruit tree that occurs in the semi-arid, deciduous savannas of Ethiopia, Eritrea, Sudan, Kenya, Uganda, Tanzania, Central Africa Republic and Democratic Republic of Congo (Kokwaro and Gillet, 1980, Hall and O’Brein, 2002, ICRAF, 2005a). Known as marula, its natural range in the region spreads from 0 to 1800 m above mean sea level, with habitat varying from dry and rocky hillsides to riparian environment, though it is most common on rocky sites with sandy to sandy

Towards sustainable management

Notwithstanding the limited development of the “Big Five”, the information available so far provides insights for mainstreaming them into smallholder farming systems in ways that improve the welfare of dryland's communities while at the same time contributing to biodiversity conservation. Assessing impacts requires identifying appropriate criteria and indicators, and the guidelines in Dry-Zone Africa Initiative for sustainable forest management (Anon., 1999) provide a useful starting point.

Implications for research and development

Despite their importance to the livelihoods of rural communities, IFTs have not been fostered by agricultural and forest policies, an observation also made by others elsewhere in Africa (Campbell, 1987). Investments in the “Big Five” provides a unique opportunity for sustainable production that could help reduce the spread of subsistence agriculture, and thus contribute to maintaining the integrity of the drylands ecosystems. This could occur through three interlinked mechanisms: (1) by

Conclusion

Development of the “Big Five” and other indigenous species in the ECA region is based on the concept of ‘use it or lose it’ and it is clear that economic incentives, focusing on household incomes, nutritional and food security, can be powerful motivators. There is continuing traditional importance of the “Big Five” throughout the drylands of the ECA region. Although there is limited trade in the tree products, at present (2006), there is extensive scope for commercial initiatives (Phofuetsile

Acknowledgements

The views expressed are the authors’ and do not necessarily reflect those of the institutions to which they are affiliated or to others referred to.

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