| dc.description.abstract | This thesis aims to assess the effects of intensive but controlled cattle grazing and trampling as
tools used to improve moribund grasslands of Lewa Wildlife Conservancy located in Laikipia region, Kenya.
These moribund grasslands are mainly dominated by Pennisetum stramineum and Pennisetum mezianum
grass species which are nutritionally poor to plains game (Lewa Wildlife Consevancy, 2007). The objectives
of this study were to assess and quantify the effects of intensive but controlled cattle grazing and trampling
on vegetation quantity, diversity and productivity and to investigate the utilization of different grazing
treatments by wild mammalian herbivores.
Changes in vegetation diversity and productivity were compared statistically between cattle grazed
areas and non-cattle grazed areas from September 2008 until April 2009. Vegetation survey was done in
the cattle corrals (bomas), controlled grazing areas and non-cattle grazing areas (controls) of the black
cotton and the mixed soils. Vegetation quantity and diversity were measured using the pin frame method
while the crude fibre and the crude protein content of the vegetation were used to estimate vegetation
quality. Data was collected during the dry season and the wet season. Vegetation productivity and off-takes
by grazers were measured by recording the growth or non - growth of vegetation inside and outside of
metal enclosure cages. Dung counts were done in each of the 60 plots.
Vegetation quantity was highest (SOO.32± 40.84 g/m2) in the non-cattle grazing zones, moderate
in the controlled grazing zones (392.0 ± 33.S2 g/m2) and lowest in the bomas (241.32 ± 27.68 g/m2). There
was a significant difference (F 2,657 = 14.304, p<O.OS)in standing crop of grass in the three zones. Species
diversity was higher in the non-cattle grazing zones than in the controlled grazing zones or the bomas and
one way ANOVA established significant differences (F2, 117 = 3.398, p<O.OS)in species diversity in the three
zones. There was a significant difference (F2, 81= 12.248, p<O.OS)in dung piles among the three grazing
zones while off-takes by mammalian herbivores were highest at the bomas (mean±SE, 37.82 ± 3.43 g/m2,
n=138) and lowest at the non-cattle grazing zones (S.S± S.6Sg/m2, n=140).
Vegetation quantity, productivity and off-takes by mammalian grazers were higher in the black
cotton soils compared to the mixed soils. However, crude proteins, crude fibres, species diversity and dung
density were higher in the mixed soils compared to the black cotton soils. Productivity in the black cotton
soils was significantly higher (t (2),138 = -3.227, p<O.OS)than in the mixed soils.
Results suggest that: the intensity of cattle grazing and trampling affected vegetation quantity but
did not affect plant species diversity. Most plains game prefer to graze in bomas as opposed to the
controlled grazing and non-cattle grazing zones probably because the bomas have lower biomass, and low
amounts of crude fibres. They also prefer to graze in mixed soils and this could be because of the high
plant species diversity of mixed soils, high amounts of crude protein contents and low biomass of grass.
Key-words: bomas, controlled grazing zones, control zones, vegetation quantity, vegetation quality, offtakes
by mammalian herbivores, dung density. | en |
