Dominating the sky-line of the Uganda-Kenya border, Mount Elgon is the eighth highest mountain in Africa and has the largest base area of any freestanding volcano in the world (Boy & Allan, 1988). The mountain is vital to the social and economic functioning of the area, and is a water catchment supplying millions of people in Uganda and Kenya (van Heist, 1994). It is also an important area for species conservation due to the richness of endemic plant and animal species which can be found on the mountain (Howard, 1991).
Physical characteristics and climate
Mount Elgon is a solitary extinct volcano straddling the border between Uganda and Kenya, 100 km north-east of Lake Victoria (figure 1). National Parks now exist on both the Ugandan and Kenyan sides of the mountain though they only merge on the north-east side of the mountain. Wagagai, the highest peak lies in Uganda and is 4321m. Despite its height, the average slope angle of Mount Elgon is less than 4 degrees (van Heist, 1994). The Ugandan side of Mount Elgon National Park covers 1145km2 between 0o52’ and 1o25’N, and between 34o14’ and 34o44’E (Howard, 1991). Mount Elgon is the oldest of the East African volcanoes, resting on the dissected peneplain of Pre Cambrium bedrock of the Trans Nzoia Plateau (Davies, 1952). The soils on Mount Elgon are from the Andisol order (“developed in volcanic ejecta”) (FAO classification). The climate of Mount Elgon shows an approximately bimodal pattern of rainfall, with the wettest months occurring from April to October (van Heist, 1994). The forest zone receives the maximum rainfall (Synott, 1968) and is important in the mountain’s role as a water catchment for several million people (van Heist, 1994).