M.Phil. dissertation abstracts 2005 - 2006
Copies of these dissertations will be held in the University of Cambridge, Department of Geography Library.
Lisa Frost Ramsay
A palaeoenvironmental study of the MzuzeWetland, Kwazulu-Natal, South Africa (supervisor: Phil Gibbard)
The Mkuze Wetland System, situated on the Maputaland Coastal Plain in northern KwaZulu-Natal, South Africa, forms a Wetland of International Importance under the Ramsar Convention. The system comprises a range of wetland types from seasonal to permanent swamps associated with the Mkuze River and the Mbazwane Stream, which converge and drain into Lake St Lucia. Because of its known ecological importance and potential, there is a need for baseline environmental data to allow for informed management of the system, yet very little is known of the environmental history of the region. A sediment and pollen study of a core collected from the Yengweni Pan provided quantitative data for the reconstruction of palaeoenvironments according to sediment structure and the vegetational spectrum. A chronology was developed through correlation with documented, dated sites where possible. This revealed that water levels in the pan have fluctuated through the Holocene in accordance with changing regional rainfall. It could also be concluded that human impact at the site only became detectable after the arrival of colonists during the 20th century and that traditional agricultural methods did not cause the environmental degradation previously suggested.
Palaeobotanical evidence of Holocene vegetation change on Little Takli Island, south Alaska, USA. (supervisor: Charles Turner)
In summer 2004, a marine-cut peat sequence was excavated on the north side of Little Takli Island, off the south coast of Alaska, USA. The peat is 250 cm deep, shows seven tephra layers throughout and was radiocarbon-dated in eight locations. The sequence is shown to span the Holocene (~8.200 C14 BP - present). Samples of 2 cm x 2cm were taken down the entire depth of the sequence and analyzed for pollen by Dr Nancy Bigelow of the Alaska Quaternary Center, Fairbanks, Alaska. Pollen evidence shows two main zones of vegeatation: 203 - 236 cm shows high concentrations of ericaceous plants as well as Betula and Sphagnum, while the second zone, from 203 cm to the top of the core shows lower, varying ericaceous and Sphagnum concentrations and much higher concentrations of Alnus and Betula. The dissertation is based on a study of plant macrofossil remains from the peat to provide greater clarity and taxonomic precision to the existing data.