A new version of an article posted in June 2011.
Range rehabilitation using reseeded enclosures in Lake Baringo Basin, Kenya
Text and photos by Stephen MUREITHI (Univ. of Nairobi, Kenya)
Editing by Willem VAN COTTHEM (Univ. of Ghent, Belgium)
Land in the Njemps Flats in the Lake Baringo Basin in Kenya is legally community owned. Uncontrolled utilization, overgrazing and mismanagement have precipitated in decades a ‘tragedy of the commons’-scenario, manifested in severe land degradation.
To address the socio-economic problems caused by severe soil degradation, the Rehabilitation of Arid Environments (RAE) Trust, initiated in 1982, established large-scale “communal” enclosures, rehabilitating the land following a participatory approach.
Communal enclosures, varying in size from 6 to 400 ha, are perimeter-fenced using a solar-powered electric fence. After de-branching the noxious woody vegetation, mainly Acacia reficiens and A. mellifera, the land was prepared for planting through chiseling to break the surface crust and construction of micro-catchments, e.g. embankments.
Drought-resistant indigenous fodder trees were planted and a mixture of grass seeds broadcasted by hand. The main grass species used included Cenchrus ciliaris, Enteropogon macrostachyus and Eragrostis superba.
Direct benefits derived from the enclosures include :
- grazing resources (dry season or livestock fattening),
- sales of cut grass for fodder or thatching,
- sales of grass seed, poles and fuel-wood,
The rehabilitation success attained in these communal enclosures soon fostered many local inhabitants to establish “private” enclosures. This gave rise to a mosaic of enclosures, differing with respect to the years since establishment, and based on two distinct management types.
A good vegetation cover within these enclosures has been reported (see http://tinyurl.com/6eje59u), resulting in a very sharp contrast between the enclosure and the surrounding open rangeland. The private enclosures, reseeded and managed by individual farmers with limited financial and technical resources, range in size from less than 1 to 20 ha. Fencing of these private enclosures is mainly done using cut-thorn bushes (Acacia reficiens and Prosopis sp.), and/or planted Pricky Pear cactus Opuntia ficus-indica and O. eliator. The latter cactus species is unfortunately invasive, and the RAE Trust has been teaching local people on choosing the right species for fencing, and how to manage and control the invasive species. Not all the farmers however, consult the RAE Trust when establishing private enclosures, but the organisation is reaching out to try to educate them on sustainable enclosure management. Read more about the enclosure story at http://www.springerlink.com/content/p5058m7107034l5m.
Our previously (2011-06) posted article, ‘Range rehabilitation by fencing it with the Prickly Pear cactus in Lake Baringo Basin’ was aimed at showing the trends of installing rangeland enclosures by private farmers in the Lake Baringo Basin. We compared photographs taken in 2005 and 2011. A lot of farmers are adopting the rangeland enclosure technique and some have used Opuntia species for fencing. Unfortunately, the readily available species Opuntia eliator, is an invasive one. At the same time, as the photos below will show, Prosopis juliflora has also aggressively invaded the area. The referred article was not aimed at implying that the RAE Trust is planting Prosopis (in fact, it has never planted any Prosopis species) and or planting / promoting Opuntia as a live fence and a rehabilitation tool. For any such impression that arose from the article, we hereby convey our apologies to Dr. Elizabeth Meyerhoff and the RAE Trust.
RAE recognizes that Prosopis juliflora is an invasive species and has worked in partnership with many organisations for years to eradicate that species from the Lake Baringo lowlands. Opuntia elatior is also recognized by RAE as an invasive species, especially as more and more people use it for fencing. RAE does not plant or promote the use of this Opuntia for fencing, but has worked with the people to manage and control it, in particular using the species as fodder during severe droughts – burning off the thorns using the wood of Prosopis and then feeding the Opuntia to cattle, thereby managing and ridding the area of both invasive species.
Need for Opuntia fences control
Prosopis upsurge in Kenya
African drylands were severely degraded by the prolonged Sahelian droughts of the 1970’s and rehabilitation through tree planting was prioritized. In Kenya, some species of the Prosopis genus were enlisted for screening because they had shown potential in rehabilitation of quarry mines (Maghembe et al 1983). The introduced species included Prosopis chilensis (Mol.) St., Prosopis juliflora, Prosopis cineraria (L.) Druce., Prosopis pallida (Humb. & Bonpl. ex Willd.) Kunth and Prosopis tamarugo Phil. (Barrow 1980, Herlocker et al., 1980, Maghembe et al., 1983). From these and other efforts, P. chilensis and P. juliflora emerged as the most promising (Barrow 1980, Herlocker et al. 1980) and their seeds were sporadically exchanged across the country (Paetkau 1980), without a trace of provenance origins.
Introduction and distribution of Prosopis germplasm did not take cognisance of the invasive traits of the species as manifested in prolific seeding, seed dispersal through livestock and prolonged viability of seeds in the soil seed bank (Otsamo et al.,1993, Shiferaw et al., 2004), hybridization (Pasiecznick et al., 2001, Vega and Hernandez, 2005, Landeras et. al., 2006), allelopathy (Goel et al., 1989, Al-Humaid and Warrag, 1998, Rizvi et. al., 1999, Nakano et al., 2003) and root plasticity (Elfadi and Luukkanen, 2006).
Prosopis invasions became a reality when the weedy potential of P. julilora was first observed in the Tana Riparian Ecosystem in 1985, but its control was considered too expensive and almost impossible because of its prolific seeding and seed dispersal by livestock (Otsamo et al.,1993). This led to planting restriction in the Tana region, but planting in other parts of Kenya continued unchecked. For example, in the Turkana District extensive planting of P. chilensis and P. juliflora continued up to early 1990s, when rehabilitation projects were active. This and other related efforts in the country contributed to widespread planting of the species that are now considered problematic outside the rehabilitation areas (Choge et al., 2002), with the wetlands being single most critical ecosystems that are under threat (Source: Muturi GM, 2011).