The climate of Eastern Africa supports a variety of forest and woodland cover from dense tropical forests, in the humid and mountainous regions of Uganda, Burundi and Rwanda, to the dry savannas of the Horn of Africa. Approximately 13 per cent of the total land area of Eastern Africa is covered in forests and woodlands, and this constitutes approximately 5 per cent of the total African forest cover. However, the percentage of forest and woodland ranges from 30 per cent in Kenya (although just 2 per cent of this is closed canopy forest), to less than 1 per cent in Djibouti (FAO 2001a, Wass 1995). There are also abundant mangrove and coastal forests in Eastern Africa. The major issue in this sub-region is conversion of natural forest to alternative land uses, predominantly cultivation and grazing, although urban encroachment is also a contributing factor.
View of Mt. Kenya National Reserve
The forests of the Eastern Arc mountain chain, running through Kenya and Tanzania, and the Albertine Rift Montane Forests of the western border of Uganda are of particular biological importance (Rodgers 1998, Mittermeier, Myers, Gil & Mittermeier 2000, MUIENR 2000). The Eastern Arc Mountains are the oldest mountains in the sub-region and their climate, influenced by the Indian Ocean, has given rise to areas of forest which have evolved largely in isolation, given their high altitude and separation from one another. Isolation has resulted in large numbers of animals and plants being endemic to these forests and they have been identified as one of the 25 internationally recognized hotspots of biodiversity. They harbour 30-40 per cent of Tanzania's species (Iddi 1998, Mittermeier and others 2000). The Eastern Arc Mountains also form the catchment for rivers supplying the hydropower that represents 61.5 per cent of Tanzania's total electricity generation capacity (Iddi 1998).
There are few estimates of the indirect value of forests in the sub-region. From the few that exist, the water catchment protection value of the Mount Kenya Forest is reported to be around US$55 million in terms of effects on production and replacement cost (Emerton 1997). The Albertine Rift Montane Forests occupy one of the most significant geological and biogeographic regions of Africa, and support a wealth of largely endemic biodiversity. The forests on these mountains play a vital role in intercepting precipitation and channelling run-off into Africa's two largest hydrological networks (The Nile and Congo basins). The forests are also important in terms of atmospheric exchanges and global and regional climate regulation, as well as protecting and enhancing soil stability and fertility (ARCOS 2000).
Although commercial timber exploitation is limited in Eastern African countries, all forest and woodland areas are important in terms of the natural resources they provide to local communities. In Kenya, it is estimated that some 2.9 million people (more than onetenth of the population of the country) live within 5 km of natural forests, (Emerton 1992). The value of forest resources to these communities has been estimated at US$94 million per year, comprising fuelwood, grazing, polewood and timber (Emerton 1993). Fuelwood and charcoal supply the majority of the sub-region's energy, meeting 96 per cent of energy needs in Uganda and 75 per cent in Kenya (FAO 2001a).
The Maasai have a well-established pharmacopoeia for treating livestock diseases. The use of more than 60 species or subspecies of plants for ethnoveterinary purposes has been documented among the Olkonerei Maasai
Non-wood forest products are also used extensively in the sub-region. In Uganda, for example the combined value of medicines, bamboo shoots, wild foods, shea butter, oil, honey, gum arabic, curios, and weaving materials has been estimated at about US$40 million per year (Emerton and Muramira 1999). The potential of medicinal plants in Eastern Africa is widely acknowledged and they are used by Maasai, Kipsigis, Turkana, and other tribes. The Maasai have a wellestablished pharmacopoeia for treating livestock diseases. The use of more than 60 species or subspecies of plants for ethnoveterinary purposes has been documented among the Olkonerei Maasai. These plants have been shown to act on a wide range of pathogens as well as regulating fertility, inflammation, and digestive disorders in livestock (Ole Lengisugi & Mziray 1996). Several of these species are now being documented and researched for potential commercial application, including the introduced tree species, Azadirachta indica which is being researched for anti-malarial properties by the Kenya Medical Research Institute's Traditional Medicine and Drugs Research Centre, Nairobi. In Uganda, the National Chemotherapeutics Research Laboratory, in Kampala, is conducting research on many indigenous plant species (Cunningham 1997).
Weaving using wood products and wood carving are important traditional crafts
that contribute substantially to household incomes and local economies in Eastern
Africa. It has been estimated that there are 60 000 woodcarvers in Kenya alone,
with each carver generating an additional five jobs in harvesting of the wood,
and sanding and polishing of the finished carvings. The annual value of exported
carvings has mushroomed from around US$60 000 in the 1950s to US$20 million
today (Cunningham 2001).