Thesis (MScConsEcol (Conservation Ecology and Entomology))--Stellenbosch University, 2008. / The fynbos eco-region in the Western Cape lowlands has been extensively transformed by
anthropogenic activities such as agriculture and urban development, as well as invasive alien
plants. Elandsberg Private Nature Reserve and Farms lies on Swartland Alluvium Fynbos and
has been largely fragmented by agricultural crop production, whilst Riverlands Nature
Reserve together with the Pella Research Site, which lie on Atlantis Sand Fynbos, are under
severe threat from the invasive woody alien Port Jackson Willow (Acacia saligna) which
forms dense stands in the lands adjacent the nature reserve. Habitat transformation has
resulted in subsequent loss of habitat and a reduction in habitat value for small mammal
communities by creating a mosaic of optimal and sub-optimal habitats. The success of A.
saligna is, in part, attributed to its production of copious amounts of small hard-shelled seeds
and well established soil seed banks. In the first part of this study we investigated the effect
of habitat transformation on resident small mammal communities by comparing small
mammal species richness, diversity and abundance between natural and transformed habitats
as well as between the two vegetation types. We also investigated the population
demographics of the striped mouse (Rhabdomys pumilio) in the different habitats. Our study
shows that whilst fragments of natural habitats, especially at Riverlands and Pella, may be
playing an important role in harbouring rare and possibly endangered species, transformed
habitats are also important as secondary habitats providing both cover as well as seasonal
food resources. Reproduction and body condition in R. pumilio were dependent on seasonal
changes such as availability of water and food resources in the habitats. The second part of
this study was carried out to investigate the effect of alien plant invasion on the resident small
mammal communities at Riverlands Nature Reserve and to determine the role of small
mammals in the removal and predation of A. saligna seeds. Rodent species richness, diversity
and abundance were very low in the A. saligna stands compared to the adjacent fynbos
vegetation. The interaction of rodents with seeds (removal or predation) was dependent upon
seed size and seed abundance in the habitats. Whilst rodents may play an important role in
predator limitation in the acacias, it is also possible that they may be playing a significant role
in dispersing the seeds of acacias into the fynbos. More work is required to fully understand
the role small mammals play in seed predation, dispersal and limitation in alien invaded
fynbos systems.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/2708 |
| Date | 12 1900 |
| Creators | Mugabe, Chapangara James |
| Contributors | Krug, Cornelia B., Matthee, Sonja, Stellenbosch University. Faculty of AgriSciences. Dept. of Conservation Ecology and Entomology. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | Stellenbosch University |
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