dc.description.abstract | Recent studies of Mirna-type earth mounds in Kenya suggest that they differ
from adjacent intermound areas in soil texture, plant species composition, primary
production and grazing value. This study investigated soil texture, nutrient status
and other functional differences between mounds and intermounds within Nairobi
National Park during four annual seasons.
Soils on the mounds had more clay and silt but less sand and gravel than
those of the intermounds. They had higher cation exchange capacity, higher
exchangeable calcium and magnesium and higher pH than intermound soils. Mounds
provided more favourable conditions for plant growth than the intermounds,
Mounds supported a more diverse botanical composition, exhibited a lower
coverage of grasses of grazing value and forbs, and a greater coverage of shrubs,
than intermounds, a pattern indicative of more intense grazing.
Net primary production was higher on the mounds. Death rate of vegetation
was higher on the intermounds while decomposition rate of dead vegetation was
higher on the mounds during the dry season. The crude protein of the two major
grass species and of bulked samples was higher in the mound samples.
Weekly animal counts showed preferential utilization of mound vegetation
during the dry season and the exclosure method showed higher grazing harvest
on mounds. | en |