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Environmental Geochemistry Research Group, Centre for Environmental Technology, Royal School of Mines, Imperial College of Science, Technology and Medicine, London SW7 2BP, UK
Concentrations of trace and major elements are examined in several soil profiles from national parks and wildlife reserves in Kenya. Broad variations in soil trace element concentrations between locations are largely attributable to differences in parent material and variations in soil pH are related to sodium and calcium concentrations. However, element concentrations and distributions are also influenced by soil forming processes. The process of sodication in alkaline solonetz soils in Lake Nakuru National Park appears to have lowered the concentrations of copper, cobalt and nickel in the surface horizon. At Amboseli National Park, a marked accumulation of molybdenum, sodium, potassium, calcium and magnesium in the surface horizon of an alkaline solonchak is probably due to salinization processes. Apparent mobilization of copper, cobalt and nickel down the profile of a humic nitisol in the Aberdares Salient is associated with eluviation and leaching processes. In two andosols and an ando-humic nitisol, copper, cobalt and nickel tend to accumulate in the surface horizon in association with organic matter. In vertisols from Amboseli National Park and Lewa Downs Wildlife Reserve, the relatively constant trace element concentrations in the A and B horizons are linked to the self-swallowing processes that characterize this soil type. The elevated pH in the solonetz and solonchak soils at Lake Nakuru and Amboseli National Parks results in enhanced uptake of molybdenum in the grass species Sporobulus spicatus. At Lake Nakuru National Park, high molybdenum concentrations in this and other plant species are associated with low copper status of impala. The implications of soil geochemistry for the trace element nutrition of wild animals in small conservation areas are discussed.
