Abstract:
Soil erosion caused by low vegetation cover associated
with agricultural land use in the catchment is blamed for
the eutrophication of Lake Victoria. Above-ground biomass
as an indicator of vegetation cover and biodiversity was
assessed using the Normalized Difference Vegetation Index,
estimation of tree density and biomass with the aim of
assessing the extent to which vegetation covers the soil
surface. Tree density is significantly different between
agricultural and semi-natural systems with an average of
96 and 90 trees ha)1 observed in Rakai and Mayuge
respectively. Agricultural fields in Mayuge (9.4 ton ha)1)
are associated with significantly higher tree biomass
compared with those in Rakai (7.6 ton ha)1). Semi-natural
systems in Rakai have an average tree biomass of
10.1 ton ha)1. Agricultural land use systems in the Lake
Victoria catchment of Mayuge resemble semi-natural systems
in terms of tree biomass as seen from satellite image
analysis, supported by extensive field observations. The
high and medium biomass cover does imply a relatively
continuous vegetative ground cover that would minimize
soil loss due to water erosion.
