Assessing The Effects Of Bush Encroachment On Species Abundance, Composition And Diversity Of Small Mammals At The Neudamm Agricultural Farm, Khomas Region, Namibia.

ABSTRACT

Bush encroachment is the conversion of open savannas to tree-dominated shrub lands. Bush encroachment results in habitat degradation and the loss of resource productivity. In this study, small mammals were used to investigate the effects of bush encroachment on biodiversity. The main aim of this study was to assess the effects of bush encroachment on the species abundance, diversity and composition of small mammals. The study was conducted in selected bush encroached and non-bush encroached sites at the Neudamm Agricultural Farm in the Khomas Region, during the “Hot-dry” season, “Hot-wet” season (April 2010) and “Cold-dry” season (July 2010). Various habitat factors, namely: woody density, woody cover and grass cover, all of which influence the diversity, distribution and abundance of small mammals were measured in the bush encroached and non-bush encroached sites. An area was considered to be bush encroached when the woody density of the encroaching species was >1,000 bushes per 1ha. Non-bush encroached sites were areas with a woody density of < 1,000 bushes per 1ha. The results revealed a significant difference in the woody density (t49=5.77; n= 50, p < 0.001), woody cover (H7=15.27, n = 8, p < 0.002) and grass cover (H7=57.30; n= 8; p < 0.001) between the bush encroached and nonbush encroached sites.