Some environmental effects of small dams on vegetation dynamics; an assessment of Maomokeani reservoir in Kitui west, Kenya
Abstract
Data from transects on the shores and drawdown area of a small reservoir in Kitui, Kenya
with a strongly fluctuating water level was used to illuminate a spatial and short-term
temporal variation in the vegetation across ecotone-ecocline zones. Sampling and
measurements were carried out between the months January 2001 to January 2002. The
period was used to capture the vegetation changes in the study area over the bimodal
rainfall pattern. The short rains were observed in the months of March to May while the
long rains occurred in the months of October to January. Samples of the data obtained
aimed at verifying the effects of reservoir waters in influencing vegetation dynamics in
terms of distribution patterns, abundance, density and diversity. The terms were analysed
with a view of using dominant species in assessing the reservoir's impact on the spatial
vegetation distribution, composition and abundance. Dominance is taken to mean the
most abundant species interms of numbers and diversity. The species were used in
analysing the spatio-temporal variation of vegetation in the reservoir with a view of
observation their patterns on ecotone-ecocline gradient basis.
The drawdown area provided a characteristic matrix of an ecotone zone with dense
perennial species of Echinochloa sp. and Polygonium sp. being common. The area above
the drawdown used here to refer to ecocline zone was characterised by woody species
interspersed with grass family species. The common species in this zone comprised of
Acacia sp., Terminalia brownii interspersed with decreasing number of Echinochloa
species. A number of species including Echinochloa sp. Acacia sp. and Terminalia
brownii exhibited significant variations in terms of biomass, cover and composition.
Citation
M.Sc. (Biogeograpy) Thesis 2005Sponsorhip
University of NairobiPublisher
Faculty of Science, University of Nairobi
Description
Master of Science Thesis