Centre for Sustainable Development Initiatives

 By Abdi Zeila

This article is in response to the news item published by The East African Standard  on the 18^th of June titled “Dreaded weed haunts residents,” referring to the invasion and colonization of pastoralist lands by the invasive alien species locally referred to as ‘Mathenge.’

More than three decades years after the introduction of Mathenge, scientifically known as Prosopis juliflora, in the drylands of Kenya there is now increasing concern about the negative impacts of the species on the lives and livelihoods of dryland communities and the ecological integrity of the essentially fragile arid and semiarid lands (ASALs). Impenetrable thickets of the species that have become established in grazing lands, croplands and along river courses tend to out-compete grass and associated rangeland forage, making its threats far outweigh any current benefits. ASAL communities, empowered by the recent environmental legislation, have made attempts to make government bodies responsible for the species’ introduction into their lands to be held accountable for the negative implications the species has had on their economic lives and livelihoods. Rulings have been made in their favour in the last few months, the government being held responsible for the species’ problems. However, the species has some useful attributes, such as charcoal production and the use of prosopis pods as dry season fodder for livestock.

Many countries, including the US, South Africa, Sudan, Argentina among others have had their share of experiences regarding colonization of lands by Mathenge. Experience shows that no country has succeeded in eradicating the weed completely. It is simply too costly to undertake any programme of that nature. Because eradication efforts have been neither cost effective nor technically successful, many countries are now engaged in programmes that seek to profit from the presence of the species. Therefore, Kenya needs to adapt land use to its management and use.

Research and development agencies, including the Kenya Forestry Research Institute (KEFRI), the Centre for Sustainable Development Initiatives (CSDI) and the Arid Lands Resource Management Project (ALRMP) have concentrated their resources in finding alternative uses for this tree which will have the dual effect of creating wealth while at the same time ameliorating its effects. Visits have been organized for technical staff engaged in Mathenge management in Kenya, including one to India, where scientists and government officials from the three institutions were able to draw useful experiences from the Indian style of managing Mathenge. In India, Mathenge is primarily used for making charcoal, and hence meets more than two thirds of the energy requirements of people living in the rural arid and semiarid lands. CSDI and ALRMP are collaborating in promoting this knowledge through stakeholder training in several affected districts.

Mathenge trees are drought resistant and can help to stem desert encroachment by growing where virtually nothing else will. They provide a useful resource for poor communities because they require low investment to develop and manage. In addition, they can improve the livelihoods of desert margin communities by providing shade, high quality timber and firewood. KEFRI, CSDI and ALRMP II have designed useful, inexpensive implements that can be used by these communities in making charcoal and animal feed from Mathenge. It is worth noting that during the lifecycle of Mathenge, nutritious human food can be derived from its pods.

These trees are the source of multi-purpose, valuable products. In the Americas, there is a history of using all tree parts. For example, tree products include wood (for timber, posts, poles, chips, charcoal and firewood) and pods (for fodder, flour, syrup, honey, resin gums, fibres, tannins and medicines). From Mexico to Peru, people have developed local economies based on Mathenge and its products. Pods are stored year-round for fodder and may be made into flour or nutritious syrup. Honey is made and gums are collected. Products are either for family use or for sale in local markets. In Colombia and Venezuela, Prosopis is sometimes referred to as ‘maíz criollo’ (‘local maize’), indicating its importance as a nutrient source for either man or animal.

Government policies shape responses to the management of the species. Government policies may also constrain the range of possible profitable uses of the species. For instance, the ban on charcoal transportation may discourage more intense and profitable use of prosopis products, which may have contributed to controlling the species’ rapid spread. GIS studies, which are complemented by socio-economic/livelihood research, can help in shaping government policies and response on the species by advocating for the establishment of a longer-term management framework. This multi-faceted framework will be used for monitoring and assessment of the species dynamics and putting in place a mechanism for rolling back the species while supporting the livelihood systems recover from the implications posed by the species. The results of the programme can also be used to extrapolate long-term implications of the species for vegetation resource dynamics and hence put in place remedial measures as necessary, since the economic mainstay of the population is livestock production.