School of Botany - Theses
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ItemAn ecological study of the sub-tidal macrophytic vegetation of three selected areas of Port Phillip Bay: Werribee, Altona and Carrum; and a literature review: sewage and oil pollution in relation to macrophytic marine algae, with a short account of the "wasting disease" of the marine angiosperm Zostera( 1970)The problems of pollution, resulting from population explosion, increased technology, industry and commerce will undoubtedly be of foremost concern for present and future generations. Pollution arises primarily from the concentration of large human populations into small areas. Populations tend to condense in urban seaboard cities, and it is in such situations that the pollutionary side-effects of economic expansion are most evident. In the United States about half the population lives on the margins of the Oceans or of the Great Lakes and in Australia at least 65 percent of the populus lives in coastal cities. Early studies of aquatic pollution centred around the fresh water environment and it is only in the last two decades that the urgency of the need for more precise scientific knowledge of the biology of marine pollution has become apparent. Consequently, the literature concerned with the ecological effects of marine pollution has increased considerably in recent years, prompted in certain instances, by the lack of knowledge evident in the handling of emergency situations such as oil spillages. Such disasters have encouraged symposia, conferences and many texts dealing with facets of marine pollution ecology. More recent publications are by Fyn (1965), Olson and Burgess (1967), Smith (1968), and Carthy and Arthur (1968). These publications review the literature available on marine pollution, but although much research is now being done to ascertain the effects of pollution. on marine organisms, its effects upon macrophytic marine algae has not received as much attention as the zoobenthos, nekton and plankton which play a more important role in food chains terminating with man. Boney (1965) has written the only review to include consideration of the economic aspects of the effects of various contaminants on seaweeds. The word POLLUTION is derived from the past participle of the latin verb 'Polluere'. The Oxford English Dictionary defines 'Pollute' as follows: To make physically impure, foul or filthy; to dirty, stain, taint or foul. Definitions of marine pollution are diverse and often contentious. However, two fundamental precepts are frequently reiterated. Firstly, that marine pollution is a man-induced phenomenon - a notable exception to this being the "red tides" or blooms of poisonous phytoplankton familiar to phycologists; and secondly, that it produces a change in the biological balance of the environment that is detrimental to marine life or man.
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ItemA primary ecological survey of the Kentbruck Heath( 1970)Introduction: The Kentbruck Heath is an area in the far southwest of Victoria, about six miles in from the coast, and almost mid-way between Portland and Nelson. The flora of the area is exceptionally rich and diverse, and is relatively undamaged. The western two thirds of the area was proclaimed as part of the Lower Glenelg National Park in 1969. For these reasons it was decided to investigate it by means of a primary ecological survey. This survey occupied only 12 months, and this limited the type of work which could be undertaken. The area known as the Kentbruck Heath can be broadly delineated on a map by the Kentbruck Road and F.V.C pine plantations on the west, Inkpot Road on the north, Heath Road and Kentbruck Settlement on the east, and other agricultural development on the south. The detailed survey was restricted to a representative square mile of this, but general observations confirm the validity of some extrapolations from the data obtained. By way of comparison, an area to the west known as Bulley Ranges has also been the subject of preliminary survey.
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ItemThe natural vegetation pattern of the Mornington Peninsula, with particular reference to the genus Eucalyptus( 1972)The natural vegetation pattern of the Mornington Peninsula, Victoria, has been studied and presented in map form on the basis of: Environmental factors associated with eucalypt distribution and habit are discussed. Vegetation formations are described and evidence presented of dependence on changing equilibria of environmental factors particularly pedological factors. Data obtained from transects across salt marshes are discussed. This indicates the inadequacy of presently available information regarding the delicately balanced environment of this formation. Difficulties in determination and delineation of plant associations are discussed. Because of species gradations it was not possible to satisfactorily separate all associations by subjective determinations alone. Abrupt discontinuity in one or more environmental factors makes it possible to subjectively determine five plant associations. A further twenty associations were determined by computer analysis of qualitative floristic lists. Delineation and problems of field recognition of these twenty statistical associations is discussed with reference to the work of Braun-Blanquet and of Poore. A preliminary attempt is made to correlate environmental factors with distribution of Eucalyptus spp., of vegetation formations, and of plant associations. Appendices include descriptions of soil types in the region; historical evidence which relates to past condition and management of the vegetation; and field data.
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ItemInvestigations into decay of standing timber in Victorian forests( 1964)The Forests’ Commission of Victoria has jurisdiction over the remaining 22,000 sq. miles of native forests in our State. Although soil conditions, temperature, rainfall etc. differ throughout the State areas of 87,884 sq. miles, the dominant members of the various forest associations are all Eucalyptus species. The best development of any forest is attained in areas of high rainfall coupled with moderate temperatures, and consequently, the largest stands of Eucalypts are found in the area classified as ‘temperate, moderate rainfall forests’. Within these forests the most abundant species is Eucalyptus regnans F.v.M., or Mountain Ash which thrives from 600’ – 1500’ on the deep fertile, well drained volcanic soil. The importance of this species can be appreciated when its abundance is considered in association with its versatility. It is eminently suitable for furniture making, building, paper pulp, boxes, cases, etc. Saw milling is the fifth most important industry in Victoria and therefore, the fact that it is rare to log a mature specimen of E. regnans devoid of decay, is cause for concern. As a result of this economic loss, the Forests’ Commission embarked on a programme of laboratory work in an attempt to evaluate the importance and extent of the various types of decay in the field. Up to this date (1940) the laboratory testing of wood blocks in relation to decay had been almost wholly confined to work concerned with timber preservation. The techniques, therefore, had to be adapted for the experiments envisaged within the proposed programme. Parkin initiated the Forests’ Commission’s work. She attempted to produce decay of E. regnans block under controlled conditions using the Bell Telephone Method in vogue at that time. Into each straight sided test jar was placed a small glass jar containing water. Each of two wooden wicks had one end in this water and the other penetrating a hole bored through a supporting slab and then into the test block. The inocula were placed on the blocks after sterilization of the system. She experienced difficulties in maintaining the moisture content of the blocks, in controlling contamination, in the lack of growth of inocula and in the decay of the wooden wicks. After twelve months only four (4) of the sixteen (16) test fungi used, gave significant losses of weight in the test blocks and no typical macroscopic rots were produced in this period. In 1939 another method of producing decay in the test blocks was published. Whilst studying termites, Leutritz found that pieces of wood infested with these organisms, decayed very readily when covered with rich garden soil. Subsequent tests confirmed his belief that soil provided a particularly suitable medium for the growth of wood rotting funghi with a resulting rapid rate of decay. His suggestion for an accelerated rate of decay was to bury test blocks in soil in the test jar and to sterilize the whole system prior to inoculation. As this method of bio-assay had not been standardized when this work was planned (1942), several variations of Leutritz’s method were tested over incubation periods of 6, 12 and 24 months. During the incubation of the test jars attempts were made to identify the test fungi, and although little success was achieved in positive identification, a useful method of distinguishing between brown and white rot fungi was devised. This thesis is concerned with wood decay and for convenience is presented in section, each of which represents a different aspect of the work.
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ItemThe distribution of Eucalyptus viminalis and Eucalyptus camaldulensis in Victoria( 1978)Eucalyptus viminalis and Eucalyptus camaldulensis are closely related and widely distributed species which may at times occupy similar habitats, although they do not usually form mixed stands. Both species show considerable variation throughout their total geographic range (Pryor 1955, Karschon 1967, Larsen 1967, Pryor and Byrne 1969), and in Victoria several forms of each species occur. Ladiges and Ashton (1974) have distinguished forest and woodland forms of E. viminalis, the former generally occurring on more fertile soils of higher rainfall areas, the latter on drier sites. Forest forms of E. camaldulensis are generally found on floodplains, whilst woodland forms commonly occupy rolling open plains and the drier margins of floodplains. The boundaries of the two species are frequently contiguous, and within the ecotone each species usually occurs in discrete stands which form patterns that are often related to topography. This study aims to describe the distribution of E. viminalis and E. camaldulensis in Victoria, and in particular to examine the habitat conditions which may account for their distribution in the riparian environment.