Human Impacts on Two Wetlands in the Nairobi National Park, Kenya
Environmental gradients in physico-chemical properties and distance to human settlements at two wetlands (around Hyena and Nalogomon dams) in the Nairobi National Park were studied. Ordination showed that over 84% of the variation in both wetland waters and soils was accounted for by twelve parameters (physico-chemical properties and distance to settlements). In wetland waters, Cu and Mn contributed most to variation that was related to distance to nearest urban settlements. This means that the concentration of the two elements increased as distance to settlements decreased. Elements Cu and Mn are pollution indicators and their increased concentration during the wet season in wetlands close to urban areas could be due to run-off or storm waters from the settled areas finding its way into the wetland. Critically, P and Cu varied along the distance gradient, being highest closest to urban settlements. The ordination plots on the wetland soil/sediment show a clear gradient, that is, a distance to urban settlements gradient that separates the two wetlands.
Agnew, A.D.Q. and S. Agnew (1994). Upland Kenya Wild Flowers. A flora of the ferns and herbaceous flowering plants of upland Kenya. East African Natural History Society, Nairobi. 374 pp.
Beentje, H.J. (1994). Kenya Trees, Shrubs and Lianas. National Museum of Kenya, Nairobi. 722 pp.
Boney, A.D. (1989). Phytoplankton. Edward Arnolds Publication, London. 118 pp.
Brix, H. and H.H. Schierup (1989). The use of aquatic macrophytes in pollution control. Ambio., 18: 101-107.
Connell, J.H. (1978). Diversity in tropical rain forests and coral reefs. Science, 199: 1302-1310.
Davis, A.P., Shokouhian, M. and N. Shubei (2001). Loading estimates of lead, copper, cadmium, and zinc in urban runoff from specific sources. Chemosphere, 44(5): 997-1009.
Grime, J.P. (1973). Control of species density in herbaceous vegetation. J. Environ. Manage., 1: 151-167.
Haines, R.W. and K.A. Lye (1983). The Sedges and Rushes of East Africa. East African Natural History Society, Nairobi.
Howard-Williams, C. and J.J. Gaudet (1985). The Structure and Functioning of African Swamps. In: The Ecology and Management of African Wetland Vegetation. A Botanical Account of African Swamps and Shallow Water bodies (Ed. P. Denny). Dr. W. Junk Publishers Dordrecht, The Netherlands. 153-175 pp.
Ibrahim, M.K. and C.H.S. Kabuye (1987). An Illustrated Manual of Kenya Grasses. F.A.O. Rome. 765 pp.
Joselow, M.M., Tobias, E., Koehler, R., Coleman, S., Bogden, J. and D. Gause (1978). Manganese pollution in the city environment and its relationship to traffic density. Am. J. Public Health, 68(6): 557-560.
Kent, M. and P. Coker (1992). Vegetation Description and Analysis: A practical approach. Belhaven Press, London, UK. 363 pp.
Mafabi, P. (2000). The role of wetland policies in the conservation of waterbirds: The case of Uganda. Ostrich,71: 96-98.
McCune, B. and M. Jefford (2006). PC-ORD. Multivariate Analysis of Ecological Data. Version 5. MjM Software. Gleneden Beach, Oregon, USA.
Mitsch, W.J. and J.G. Gosselink (2007). Wetlands. John Wiley and Sons, Hoboken, New Jersey. 582 pp.
Mworia, J.K., Kinyamario, J.I. and E.A. John (2008). Impact of the invader Ipomoea hildebrandtii on grass biomass, nitrogen mineralization and determinants of its seedling establishment in Kajiado, Kenya. African Journal of Range and Forage Science, 25: 11-16.
Rencher, A.C. (2002). Methods of Multivariate Analysis. John Wiley and Sons. New York. 708 pp.
Stevens, J. (1986). Applied Multivariate Statistics for the Social Sciences. Lawrence Erlbaum Associates, Hillsdale, NJ. 629 pp.
Van Der Weghe, J.P. (1981). Avifauna of papyrus in Rwanda and Burundi. Gerfaut, 71: 489-536.
Whigham, D. and J.T.A. Verhoeven (2009). Wetlands of the World: The next instalment. Wetlands Ecol. and Manage.,
17: 167-167.