Tsetse control and land-use change in Lambwe Valley, south-western Kenya
Abstract
In areas of Africa infested by tsetse, their control is usually seen as
simultaneously contributing to human health and agricultural production. For a
long time trypanosomosis* (both sleeping sickness and nagana), constrained
human settlement and agriculture in the Lambwe Valley, south-western
Kenya. Through many years of tsetse control, people have been encouraged
to settle in the valley, and changes in land-use are taking place. The Ruma
National Park, the only one in East and Central Africa with the roan antelope,
is strapped in the midst of intensifying human habitation. This study was
designed to assess changes in land use in the settled areas of the valley, and
land cover change in the national park. It sought to establish the role that
tsetse control may have played in these changes, and the implications of the
changes in the settled areas of the valley, and on tourism and wildlife in the
park. It employed time-series aerial photograph interpretation and social
surveys to investigate changes in land-use between 1948 and 1993 in the
valley. A demographic study of the processes of human population growth
from 1948 to 1999 was complemented by a community time-line detailing
important events in the area. Measurements of bare ground, litter, biomass
and species abundance were taken to emphasise differences between the
Ruma National Park and the settled areas of the valley. Findings indicated a
23% increase in cultivation in the settled areas over the studied period, with
consequent decreases in woody vegetation and grasslands. In the Ruma
National Park, shrublands expanded by over 10%, woodlands by over 3%,
while grasslands decreased by over 14%. Human population growth rates
were highest in the years following intensive tsetse control, attributed to
immigration into the valley, and peaked at 7.14% between 1962 and 1969.
The apparent merging of thickets in the park, which comprise the most
potential tsetse habitat could precipitate an upsurge in tsetse, and are
unsuitable for the mainly grazer wildlife populations therein, a phenomenon
which could fuel conflicts with settlers in .the valley, and potentially affect
tourism in the park negatively. That' most of the shrub species are fireresistant
calls for a combination of bush control methods to contain the trend.
This study recommends continued tsetse surveillance and control. Due to the
pressures being experienced in the settled areas of the valley, intensification
of agriculture is proposed as a feasible option, if the trends in land-use
continue as observed in this study. The settled areas have higher bare ground
percentages and vegetation species of low graze value, and lower biomass
and litter than in the park. These results emphasized the impacts of humandominated
land-uses in an initially similar ecosystem. Potential to improve the
pastures for better output is recommended as a contribution to agricultural
intensification. The control of tsetse is seen as having ameliorated an
important constraint to human settlement and habitation through reduction in
sleeping sickness, and its removal as playing a role in the land-use changes
through livestock support to open up land for cultivation.
Citation
Muriuki Grace Wanjiku (2002).Tsetse control and land-use change in Lambwe Valley, south-western Kenya. A thesis submitted to the Department of Range Management, University of Nairobi, in partial fulfilment of the requirements for the Degree of Master of Science in Range Management (Ecology Option).Publisher
University of Nairobi School of Biological Sciences,