Resource Management and Geography - Theses
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ItemA geomorphological study of Spartina Townsendii (Sensu Lato) marshlands in Australia( 1981)The halophytic grass Spartina townsendii (s.l.) was widely introduced from England to Australia in the late 1920s and early 1930s, but has established successfully only in estuaries and lagoons in the south east of the country. It now occupies 620 ha, the major stations being the Tamar River, Tasmania, where the fertile form of the grass was planted in 1947, and Andersons Inlet, Victoria, where the same vigorous species was introduced as recently as 1962. Because of their comparative youth, Australian Spartina marshes are in a much earlier stage of development than many marshes in Britain, where S. townsendii (s.l.) was first collected in 1870. It has therefore been possible to examine in this country the initial and early stages of Spartina marsh formation. Particular attention has been given to Andersons Inlet, where the growth of Spartina and the accompanying transformation from mudflat to marshland have been observed from the time of marsh inception. By 1980, Spartina in Andersons Inlet occupied 63.6 ha. In favourable environments, Spartina cover in sample quadrats was approaching 100 per cent after 14 years from initial establishment of seedlings and young plants. Colonisation commenced within a narrow vertical range of 0.61 m to 0.83 m above Inverloch datum, but Spartina quickly expanded both seawards and landwards to its present vertical limits of 0.25 m and 1.13 m. The seaward limit of Spartina is now regularly submerged by both spring and neap tides for more than 6 hrs, while the landward limit is submerged by mean spring tides. Spartina has similar submergence limits at other Australian stations, and is most abundant in sheltered conditions regularly inundated by water of less than 18%o salinity. At many sites the spread of Spartina has been accompanied by rapid accretion of sediment, which is trapped and retained by plant foliage. Sediment deposition in Spartina at Andersons Inlet is generally greater than 2 cm per annum, and rates of up to 7 cm per annum have been recorded. The role of Spartina in promoting accretion may be apparent even before sward formation is completed, as indicated by the development of microtopographic highs coincident with Spartina clones and clumps. As a result of high rates of accretion, previously unvegetated mudflats are rapidly transformed into depositional terraces, of which six major types may be recognised. Their upward growth is accompanied by a change from non-channelised to partly channelised tidal flow, as creeks develop between Spartina tussocks and within continuous sward. Pans may form on the surface of the marsh as a result of deposition of tidal wrack, impeded drainage, or restriction of light beneath mangroves. Spartina thus acts as a geomorphological agent, by greatly accelerating the processes of marsh formation.
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ItemDryland salting in Victoria and Western Australia: a literature review( 1982)Soil salination is the accumulation of soluble salts in the root zone in excess of the level able to be tolerated by the vegetation community. There are two processes by which this may occur; irrigation induced soil salinisation, and a group in non-irrigated areas, collectively known as dryland salting. Irrigation salting has been recognised for thousands of years (Jacobsen and Adams, (1958) quoted by Peck, 1978). However no such ancient references are presently known in the case of dryland salting. Dryland salting appears to be a relatively recent phenomenon. In order to review the literature relevant to dryland salting only the major contributions from Western Australia and Victoria are discussed. Dryland salting is known to occur in every Australian state, though as yet discussions of it have not found their way into the scientific literature. The Northern American literature was also omitted as the nature of their problem is different – owing to the geological type. Although their literature would be useful if the review was orientated towards solutions to the problem of dryland salting. The review discussed the changing nature of the literature noting the move from the “qualitative” approach of the early authors (Burvill, 1945; 1950 and Teakle, 1953) to a more recent detailed and “quantitative” one (Peck and Hurle, 1973 and Holmes and Talsma, 1981) . Furthermore it contrasts the amount and type of research completed in Western Australia and Victoria, noting the dominance of the first mentioned state.
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ItemGrazing the high country: an historical and political geography of high country grazing in Victoria, 1835 to 1935( 1980)Someone once said that if there is one lesson man can draw from history it is that man learns nothing from history. In my experience this observation often relates to the commonly held belief that history has little to contribute to the day to day "nuts and bolts" functioning of society. The thinking goes if history cannot supply the answers to practical problems then what is it worth? Such is the view of the pragmatist. Consequently some people will regard this thesis as being interesting in a purely antiquarian sense. If, however, one has a somewhat broader perspective and can see beyond the immediate problems of each day to underlying trends and inherent philosophies, then one will appreciate what this thesis has to offer. For, while it does not provide immediate solutions to existing land use conflicts associated with high country grazing, it does shed light on their origins and development, and hence their basic character.