Kenya Long-term Exclosure Experiment

Over 70% of the land area of Africa is arid or semi-arid. Rapidly growing populations and ongoing economic development are putting tremendous pressures on these lands (Bernard et al. 1989). These pressures can result in local, regional, and global problems, including soil erosion, threats to endangered species such as elephants and rhinos, and desertification, with its potential effects on global warming. In response to these serious problems, the Government of Kenya (through the National Museums and the Kenya Wildlife Service) is collaborating with the Smithsonian Institution and Princeton University to establish a research and training center for arid ecosystem studies. This center is located on Mpala ranch, a 45,000 acre property in the center of the Laikipia Plateau in Kenya. The goal of this center is to provide the information, expertise, and training that will allow Kenya (and other nations in the region) to wisely manage, develop, and conserve their arid land resources. For virtually all indigenous animal species in Kenya, there are more individuals outside protected areas than inside them, mostly on arid and semi-arid lands. The future of these populations will depend on the interaction between enlightened rangeland management and wildlife needs. There is growing evidence that many wildlife species are not incompatible with intensive livestock production, and can even be beneficial. Also, wildlife can provide much needed additional revenue in the form of tourism or game ranching. A mixed strategy of wildlife and cattle may be optimal, both for economic return and for the maintenance of biodiversity. There is considerable literature on the effects of various cattle grazing and burning strategies on range quality in Africa, and on the effects of indigenous herbivores on the vegetation of protected areas. However, almost little is known about the interactions among wildlife, domestic stock, and vegetation, and there have been no controlled experimental studies of the separate and combined effects of wild and domestic herbivores on vegetation and on each other. This information is vital if we are to make informed decisions about the future of wildlife on the vast unprotected grazing lands of Africa. We are engaged in a long-term experimental study of these interactions at the Mpala Research Centre in Laikipia, a working cattle ranch and an area rich in wildlife. For example, the Laikipia ecosystem has the second largest population of elephants in Kenya; as many as 900 elephants periodically occur on Mpala. There are also at least twenty additional species of large indigenous mammals.