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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Studies of the biology of four species of Dicranoloma.

Milne, Josephine, mikewood@deakin.edu.au January 1997 (has links)
Populations of Dicranoloma billardierei (Brid) Par., D. dicarpum (Nees.) Par., D. menziesii (Tayl.) Par. and D. platycaulon (C. Muell) Dix, from two pockets of cool temperate rainforest within the Yarra Ranges National Park (Cement Creek and Myrtle Loop), were sampled for a period of two years to establish their reproductive biology. The population dynamics within quadrats of D. billardierei, D. menziesii and D. platycaulon at Cement Creek also was investigated over a two year period, through the seasonal recording of shoot loss and/or gain, The four species of Dicranoloma were dioicous and sexually dimorphic, with dwarf males epiphytic on the female plants. Antheridia were initiated before archegonia and required ca, 6 months to reach maturity, compared with 1 to 2 months for archegonia. More archegonia than antheridia occurred per inflorescence and were more variable Fertilization occurred during winter in D. billardierei and summer/ autumn in D. menziesii and D. platycaulon. The duration of the sporophyte cycle of D. menziesii was 12 months, shorter than that of D. billardierei and D. platycaulon which lasted for a period of 18 months to 2 years. In the latter two species an overlap of sporophyte generations occurred. This was particularly pronounced in D. billardierei as sporophytes remained in the swollen venter maturation stage for a period of 6 months. The duration of the sporophyte cycle could not be ascertained as few fruiting stems of D. dicarpum were found. All four species of Dicranoloma regenerated from fragments cultured in the laboratory, and only two of the species showed evidence of production of asexual propagules in the field. Dicranoloma dicarpum was found to produce gemmae, an observation which had not been recorded before, and most of the leaves on stems of D. platycaulon had detached subulas. Shoot loss was minimal in all four species, and when it did occur, (eg D. billardierei) it was attributed to disturbance by animals. Within quadrats there was an increase in shoot density which resulted from the development of innovation(s) and/or side branches rather than from the recruitment of new plants from spores or the regeneration of asexual propagules. The four species of Dicranoloma investigated were robust, perennial mosses and formed an important component of the bryophytes found within the study area. Dicranoloma menziesii was the predominant species establishing on a variety of substrata, particularly as an epiphyte on Nothofagus cunninghamii The other species were more selective in their choice of substratum. Dicranoloma platycaulon was found exclusively on the trunks of myrtle beech and D. billardierei on fallen logs and exposed roots. Dicranoloma dicarpum which was not common, grew as an epiphyte on myrtle beech and on rocks.
62

The Effects of Phytophthora Cinnamomi on heathland flora and fauna of the Eastern Otway Ranges.

Laidlaw, William Scott, mikewood@deakin.edu.au January 1997 (has links)
The plant pathogen, Phytophthora dnnamomi, is a cause of dieback disease observed in sclerophyll vegetation in Australia, The effects of P. dnnamomi on flora and fauna were studied at two locations in heathland vegetation near the coastal town of Anglesea, Victoria. The pathogen was isolated from soils beneath diseased heathland plants. The extent of diseased vegetation was assessed by the presence and absence of highly sensitive indicator species, Xanthorrhoea australis and hopogon ceratophyllus. The characteristics of heathland vegetation exhibiting dieback disease associated with the presence of P. dnnamomi were investigated. Plant species richness was similar between diseased and non-diseased areas however diseased areas were characterised by significant declines in the cover and frequency of susceptible species, increases in resistant species and increases in percent cover of open ground. Compared to non-diseased areas, diseased areas exhibited fewer shrub species and decreased shrub cover. The percentage cover and number of species of sedges, lilies and grasses were higher in diseased areas. Structural differences were significant between 0-0.6 m with decreased cover of vegetation in diseased areas. Differences in structure between diseased and non-diseased areas were not as great as expected due to increases in the cover of resistant species. A number of regenerating X australis were observed in post-disease areas. Cluster analysis of floristic data could clearly separate diseased and non-diseased trap stations. The population dynamics and habitat use of eight small mammal species present were compared in diseased and non-diseased areas using trapping and radio-tracking techniques. The number of small mammal species captured in post-disease areas was significantly lower than non-diseased areas. Mean captures of Antechinus stuartii and Rattus fiisdpes were significantly lower in diseased areas on Grid B. Mean captures of Rattus lutreolus were significantly lower in diseased areas on both study grids. Significant differences were not observed in every season over the two year study period. Radio tracking revealed more observations of Sminthopsis leucopus in non-diseased vegetation than in diseased. Cercartetus nanus was frequently observed to utilise the disease susceptible X. australis for nesting. At one location, the recovery of vegetation and small mammal communities in non-diseased and diseased vegetation after fuel reduction burning was monitored for three years post-fire. Return of plant species after fire in both disease classes were similar, reaching 75% of pre-fire richness after three years. Vegetation cover was slower to return after fire in diseased areas. Of the seven small mammal species captured pre-fire, five were regularly captured in the three years after fire. General linear model analysis revealed a significant influence of disease on capture rates for total small mammals before fire and a significant influence of fire on capture rates for total small mammals after fire. After three years, the influence of fire on capture rates was reduced no significant difference was detected between disease classes. Measurements of microclimate indicate that diseased, burnt heathland was likely to experience greater extremes of temperature and wind speed. Seeding of diseased heathland with X. australis resulted in the establishment of seedlings of this sensitive species. The reported distributions of the mamma] species in Victoria were analysed to determine which species were associated with the reported distribution of dieback disease. Twenty-two species have more than 20% of their known distribution in diseased areas. Five of these species, Pseudomys novaehollandiae, Pseudomys fumeust Pseudomys shortridgei, Potorous longipes and Petrogale pencillata are rare or endangered in Victoria. Four of the twenty-two species, Sminthopsis leucopus, Isoodon obesulus, Cercartetus nanus and Rottus lutreolus am observed in Victorian heathlands. Phytophthora cinnamomi changes both the structure and floristics of heathland vegetation in the eastern Qtway Ranges. Small mammals respond to these changes through decreased utilisation of diseased heathland. The pathogen threatens the diversity of species present and future research efforts should be directed towards limiting its spread and rehabilitating diseased areas.
63

Conservation assessment of remnant vegetation in the Mount Lofty Ranges, South Australia

Mitchell, Leslie Howard, n/a January 1983 (has links)
This study is concerned with programs to conserve remnant stands of native vegetation in the agricultural regions of South Australia and concentrates on the development of explicit evaluation procedures which reflect stated conservation objectives. As botanical data are available for stands of native vegetation in most of the agricultural regions, stands in a particular region are able to be compared rather than assessed in isolation. Based on a review of conservation evaluation schemes in Australia and overseas, a hierarchical evaluation procedure using multiple criteria to compare stands was applied to stands of vegetation in the Mount Lofty Ranges. The conservation objective, of preserving samples of all plant communities in a region, led to the analysis of existing botanical data from two surveys of the Mount Lofty Ranges, to provide the basis for an inventory of regional plant communities. These surveys included 52 remnant stands of native vegetation and employed a point-centred quarter plotless sampling technique to summarise the vegetation. Numerical classificatory analysis of the raw sampling point data produced a more comprehensive floristic summary than the results from the plotless sampling. These floristic groups were correlated with physical environmental variables to produce an inventory of 45 regional vegetation types, as the first stage in the conservation evaluation of stands. Evaluation criteria of size, species richness and species rarity were quantified and used to select examples of each vegetation type on the basis of overall satisfaction of the criteria. In addition, the smallest suite of stands, in which all the vegetation types were represented, was determined, and was shown to be 24 stands. All of these were included in the 37 stands chosen using the three criteria. A third evaluation stage used stand parameters such as plant community richness to give a priority ranking of the 37 stands. A polythetic divisive classification of the vegetation types was developed to provide a means of evaluating communities in stands of native vegetation yet to be sampled in the region, and of comparing the vegetation types with communities in existing reservesr Examination of species-sampling area relationships led to recommended plot sizes for such future vegetation surveys in the Mount Lofty Ranges. The ease of collecting floristic data and the extensive time involved in quantitative measurements suggest that all perennial plant species be recorded and only estimations be made of vegetation quantity and structure for each sampling plot. This study demonstrates the usefulness of numerical classification techniques for conservation evaluation, and of continuous variables to quantify criteria of conservation value; and the application of those criteria in an explicit, hierarchical conservation evaluation procedure.
64

Mammals of the dreaming : an historical ethnomammalogy of the Flinders Ranges

Tunbridge, Dorothy, n/a January 1996 (has links)
This work is a linguistically based historical ethnography of the mammal species of the Flinders Ranges, South Australia, from pre-European times to the present day. The research was motivated by linguistic evidence in the Adnyamathanha people's language, Yura Ngawarla, for the recent existence of a number of mammals in the Flinders Ranges region. The work aims firstly to identify each species represented by those language terms and to discover the identity of other species also present in the past 200 years. Secondly, it aims to present an exhaustive ethnography of mammals for that region. This work is essentially cross-disciplinary, with research extending into the often overlapping fields of linguistics, anthropology, archaeology, applied science, historical zoology and history. Comparative linguistics, oral tradition, historical records, scientific data and sub-fossil material are used to identify the species present at European occupation and their role in traditional Aboriginal life, and in passing, to establish the former existence and distribution of those species throughout the region of the two South Australian gulfs. An inventory of extant and extinct Flinders Ranges species is established. Linguistic, ethnographic, zoological and historical data are used to estimate when species extinction occurred, and what may (or may not) have been the main factors involved. A significant outcome of this work is the documentation of a part of Aboriginal knowledge which itself was on the verge of extinction, and the affirmation of well attested Aboriginal oral tradition as an authentic 'authoritative source'. Conclusion: Prior to European occupation the Flinders Ranges had a rich mammalian fauna comprising around 60 native species. These played a significant part in Aboriginal people's diet, manufacturing industry and cultural and spiritual life. By the end of the first half century of European occupation or soon after around two thirds of the terrestrial species had vanished. The effect of these events on Aboriginal people's ability to survive in their own territory was devastating and irreversible.
65

Strategic revegetation planning in an agricultural landscape: A spatial information technology approach

Bryan, Brett A January 2000 (has links)
Revegetation is required to conserve the biological diversity of over-cleared and fragmented agricultural regions. This dissertation represents an application of spatial information technologies to environmental management. It makes a significant contribution to the integration of general landscape-scale principles into restoration ecology. New and established quantitative, spatial analytical techniques are used in environmental modelling, ecological assessment and in setting geographic priorities for strategic revegetation planning in the Mt. Lofty Ranges in South Australia. This is one of the first assessments of the adequacy and representativeness of remnants in an agricultural region and one of the first attempts to apply these landscape-scale conservation principles to the field of restoration ecology. The adequacy of the remnant ecological system is assessed in terms of the landscape structure. Landscape ecological principles provide a basis for setting geographic priorities for the revegetation of an adequate remnant ecological system. Although seldom quantified, it is often thought that remnants in agricultural regions are not representative of the regional physical environmental heterogeneity. The representativeness of remnant vegetation is assessed in the study area and a complex effect of land clearance and reserve selection on representativeness is revealed which has significant implications for strategic revegetation planning. Land clearance has precluded the use of information on the spatial distribution of biological diversity in agricultural regions. Hence, a surrogate is required in strategic planning for the restoration of a representative regional ecological system. The degree of vegetation/environment convergence is assessed to investigate the viability of using the physical environment as a surrogate for the distribution of biological diversity. An index of coincidence is developed specifically for this purpose. An environmental classification is then derived for use in setting geographic priorities for the restoration of a representative regional ecological system. Three complementary techniques are used to find the simplest classification possible that does not have overly broad environmental classes. Geographic priorities are suggested according to the distribution and representativeness of environment types in the study area. In the light of the results of this dissertation, a research direction for restoration ecology in agricultural landscapes is mapped out. / Thesis (Ph.D.)--Department of Geographical and Environmental Studies; Department of Applied and Molecular Ecology, 2000.
66

Sedimentology of the late Precambrian Mundallio Subgroup : a clastic - carbonate ( Dolomite, Magnesite ) sequence in the Mt. Lofty and Flinders Ranges, South Australia

Uppill, Robin K January 1980 (has links)
During deposition of the mixed carbonate - clastic sequence of the Mundallio Subgroup, the " Adelaide Geosyncline " was a very shallow, elongate sedimentary basin, flanked to the west and east by older Precambrian basement. In much of the southern and northern Flinders Ranges, clastic deposition predominated in the lower Mundallio Subgroup. In the north, alternating development of shallow mudflats and sandflats ( Nankabunyana Formation ) depended on the interplay between the sediment supply and winnowing processes, while dolomite mudstones were locally deposited in the shallowest areas. In the eastern half of the Willouran Ranges, massive shales were deposited as the environment remained persistently below wave base ( Camel Flat Shale ), but a renewed sand influx led to deposition of the Tilterana Sandstone. In the southern Flinders Ranges, terrigenous clay and silt were deposited on submergent mudflats which shallowed into intermittently exposed dolomite mudflats ( Nathaltee Formation ). Dolomite mudflats were a more persistent feature in areas more distal from the terrigenous source, and sometimes contained isolated, ephemeral lakes which were sites of magnesite deposition ( Yadlamalka Formation ). Dolomite and magnesite mudstone deposition of the Yadlamalka Formation became wide spread in the northern and southern Flinders Ranges in the upper Mundallio Subgroup, as shallowing and retreat of the basin margin led to the formation of semi - isolated lakes, separated and enclosed by exposed carbonate mudflats. The elastics deposited in association with these carbonate mudstones consisted largely of sand sized detritus, probably derived from the reworking of aeolian deposits. In the eastern Willouran Ranges, the greater influx of sand and the slightly deeper, largely submergent environments, led to the deposition of the sandstones, dolomites and siltstones of the Mirra Formation. Because of little clastic influx into the northern Mt. Lofty Ranges, shallow to occasionally exposed environments were largely sites of dolomite deposition ( Skillogalee Dolomite ). To the south, shales were deposited in slightly deeper environments ( Woolshed Flat Shale ), although local dolomite deposition occurred in the Adelaide region ( Castambul Formation, Montacute Dolomite ). In the uppermost part of the subgroup, the area of shale deposition extended northward, encroaching over the dolomite mudflats of the upper Skillogalee Dolomite. Dolomite, occurring largely as mudstones, is the major carbonate mineral present in the Mundallio Subgroup, but magnesite is also widespread. Limestones are not present. The carbonates experienced minor replacement by early diagenetic chert, initially precipitated as both crystalline and amorphous phases. Within the upper Mundallio Subgroup, the preservation of fine details of the detrital texture of dolomite mudstones and peloidal dolomites, and the high Sr contents of dolomites ( largely in the range of 400 - 650 ppm ), suggest that these sediments consisted of Ca - Mg carbonates ( protodolomite, Mg - calcite ) at the time of deposition. Slightly greater recrystallisation of dolomites in the lower Mundallio Subgroup resulted in their lower Sr and higher Mn and Fe contents. Magnesite mudstones may have initially precipitated as hydrated Mg - carbonates. Lithification of surface sediments as a result of subaerial exposure, led to the formation of micritic magnesite. Much of this magnesite was subsequently reworked into intraclastic beds. The carbonate mineralogy of this sequence, and the evidence of only rare sulphates, indicate that the carbonates were precipitated from alkaline, Mg - Ca - C03 waters, with a higher carbonate and lower sulphate content than seawater. / Thesis (Ph.D.)--Department of Geology and Mineralogy, 1980.
67

The impacts of sambar (Cervus unicolor) in the Yarra Ranges National Park

Bennett, Ami January 2008 (has links)
Internationally, the impacts of deer have been widely studied, but little work has been conducted in Australia. Sambar (Cervus unicolor Kerr) were introduced to Victoria in the 1860s from Sri Lanka, and have become established throughout eastern Victoria. This study is located in the Yarra Ranges National Park, 100 km north east of Melbourne. The park primarily consists of three protected water catchments that contribute approximately 50% to Melbourne’s water supply. This study was conducted from 2005 to 2008 in the Upper Yarra and O’Shannassy catchments. Large open areas covered by forbs and grasses periodically form adjacent to the water body of the Upper Yarra reservoir. Sambar are frequently observed at the largest of these areas known as The Flats. The impacts of sambar at this locality and in other areas of the catchments were investigated. / Faecal pellet transect surveys determined that sambar occupancy and density was greatest on open flats, lower on forest edges adjacent to open flats (< 250 m), and significantly less in other forested areas of the catchment. Observations of The Flats revealed that hinds were the main demographic class represented, with a mean group size of 39 individuals, and up to 70. This is the largest aggregation of sambar ever reported anywhere in the world, and equates to an approximate density of 200 km-2 at this site. / Selective exclosures effectively differentiated the offtake of forage by sambar from that of native herbivores. Sambar contributed to the majority of offtake at The Flats, and were able to obtain a substantial proportion of their daily food requirements from this source. A culling program began in the Yarra Ranges National Park in May 2008, to reduce the large numbers of deer in the park. The cull reduced the time spent by sambar on The Flats, as determined by faecal pellet accumulation plots, and significantly reduced faecal pellet load and forage offtake. / Sambar significantly decreased relative foliage cover of shiny nematolepis (Nematolepis wilsonii), a threatened understorey tree, through their antler rubbing activities. Thrashing of shiny nematolepis saplings also significantly decreased relative foliage cover, with sambar selecting saplings with a larger stem diameter from those available. Rubbed trees and thrashed saplings experienced damage to, on average, over half the stem circumference. / Selective exclosures allowed differentiation of sambar and native herbivore browsing on forest understoreys. Browsing by sambar in high densities prevented the vertical growth of plants in the understorey, with branches above 60 cm in height most commonly browsed. Plants in the understorey were more frequently and intensely browsed in areas of high sambar density. Three species were browsed to a significantly greater extent by sambar than native herbivores: hazel pomaderris (Pomaderris aspera), prickly tea-tree (Leptospermum continentale) and prickly bush-pea, (Pultenaea juniperina). Sambar significantly reduced plant biomass in forest understoreys where they occur in high densities. / The presence of large, open herb-rich areas drives the high local densities and associated impacts of sambar within the Yarra Ranges National Park. Future areas of research are identified and management recommendations are outlined. A sustained culling program appears to be the only practical option to reduce sambar density and impacts at this locality.
68

Ecological studies of arid rangelands in South Australia

Lay, Brendan G. January 1972 (has links) (PDF)
No description available.
69

Effects of stream restoration on macroinvertebrate communities in an Oregon Coast Range system

Christensen, M. Jo 09 February 1996 (has links)
Stream-restoration projects are usually designed to improve habitat quality for fishes. These projects manipulate flow patterns, substrate distribution, and amount and placement of large woody debris. Consequently, they also affect the size and composition of the aquatic macroinvertebrate community. This research evaluates two types of fish habitat restoration: off-channel structures (alcoves) and in-channel structures (log weirs). I compared macroinvertebrate habitats and communities in natural and artificial alcoves in Upper and South Fork Lobster Creeks, Lane Co., and examined the effects of log weirs on in-channel habitat diversity, community composition, drift patterns, and fish consumption of macroinvertebrates. Macroinvertebrate samples were collected from artificial and natural alcoves using hand pumps and D-nets. Within the channel, macroinvertebrates were collected from restored and unrestored reaches with a Hess sampler and using a stratified random sampling scheme. Forty-eight hour invertebrate drift samples were obtained at outlets of log-weir pools. Stomach contents were obtained from coho salmon (Oncorhynchus kisutch) and cutthroat trout (O. clarki) in restored reaches. Although natural alcoves differed from artificial in location within the floodplain, morphology, permanence, and degree of interaction with the stream channel, both alcovetypes provided similar habitats and contained similar macroinvertebrate communities. Average densities and diversity within the alcoves depended on habitat and time of year. Average densities were higher in artificial than in natural. Alcoves contained 29% of species richness within Upper Lobster Creek. Within the stream channel, the diversity of macroinvertebrate habitat was lower in restored than in unrestored sections. Log weirs were associated with reduced taxonomic and functional feeding-group diversity. Composition of drift was not significantly different in restored and unrestored areas; however, drift densities were significantly lower in restored reaches. Diets of fishes in restored areas were composed primarily of organisms produced from outside restored areas. Although in-channel structures may enhance physical habitat for fishes, they may alter or reduce the availability of food for fishes feeding on drifting invertebrates. Recommendations are given for improving the design of stream restoration projects with respect to macroinvertebrates; however stream restoration should focus on restoring whole-system integrity and function, instead of targeting just one or two types of organisms. / Graduation date: 1996
70

Influence of geomorphology and land use on distribution and abundance of salmonids in a coastal Oregon basin

Schwartz, John Steven 20 November 1990 (has links)
Graduation date: 1991

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