Assessing the effects of bush encroachment on species abundance, composition and diversity of small mammals at the Neudamm Agricultural Farm, Khomas Region Namibia
Loading...
Date
2011
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Abstract provided by author
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
The data on the abundance of small mammals were collected using Sherman-live traps (23 x 8 x 9cm) which were set out over an area of 100 m x 100 m for both the bush encroached and nonbush encroached sites. This comprised a trapping grid. In each grid traps were placed in ten rows and ten columns and were spaced at 10 m intervals. A total of seven small mammal species were captured during the study. Five of these small mammals species (Rhabdomys pumilio, Micaelamys namaquensis, Elephantulus intufi, Gerbilliscus leucogaster and Thallomys paedulcus) captured were identified to species level. The other two small mammal species (Crocidura spp. and Mastomys spp.) captured were identified to genus level. A total of 241 individuals of small mammal species comprising five species were recorded in the bush encroached sites. A total of 249 individuals of small mammal species comprising five species were also recorded in the non-bush encroached sites. The study revealed that there was no significant difference in the abundance (÷217 = 18.00; n = 18; p=0.39), population density (H8=1.19; n = 9; p=0.76) and diversity (H8=1.98; n= 9; p= 0.576) of small mammals between the bush encroached and non-bush encroached sites. The Hierarchical cluster analysis (HCA) revealed that there was no difference in the composition of small mammals between the bush encroached and non-bush encroached sites. The study showed that bush encroachment did not have a significant effect on small mammal populations
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
The data on the abundance of small mammals were collected using Sherman-live traps (23 x 8 x 9cm) which were set out over an area of 100 m x 100 m for both the bush encroached and nonbush encroached sites. This comprised a trapping grid. In each grid traps were placed in ten rows and ten columns and were spaced at 10 m intervals. A total of seven small mammal species were captured during the study. Five of these small mammals species (Rhabdomys pumilio, Micaelamys namaquensis, Elephantulus intufi, Gerbilliscus leucogaster and Thallomys paedulcus) captured were identified to species level. The other two small mammal species (Crocidura spp. and Mastomys spp.) captured were identified to genus level. A total of 241 individuals of small mammal species comprising five species were recorded in the bush encroached sites. A total of 249 individuals of small mammal species comprising five species were also recorded in the non-bush encroached sites. The study revealed that there was no significant difference in the abundance (÷217 = 18.00; n = 18; p=0.39), population density (H8=1.19; n = 9; p=0.76) and diversity (H8=1.98; n= 9; p= 0.576) of small mammals between the bush encroached and non-bush encroached sites. The Hierarchical cluster analysis (HCA) revealed that there was no difference in the composition of small mammals between the bush encroached and non-bush encroached sites. The study showed that bush encroachment did not have a significant effect on small mammal populations
Description
A thesis submitted in partial fulfillment of the requirement for the degree of Master of Science in Biodiversity Management and Research
Keywords
Range management Namibia, Biological diversity conservation, Agrobiodiversity Namibia, Animal diversity conservation Namibia