Dissertations / Theses on the topic 'Southern Tablelands of New South Wales'

Clearance of Eucalyptus woodlands has resulted in soil deterioration and lost agricultural production, due to wind erosion, salinity and soil acidity. Despite increasing efforts to reverse these trends through Landcare and other revegetation and agroforestry programs, there is a lack of experimentally-based information about the effects of trees on native pasture performance. The study was carried out in a temperate environment (Southern Tablelands, New South Wales). The altitude at the study sites ranged from 740 to 880m and the aspect at the experimental plots varied from SE to SW. The nearest site was 16 km from Canberra Airport and all sites were situated within similar rainfall isohyets as Canberra Airport. Thus climatic conditions were expected to be similar. Climate records at Canberra Airport indicate that January is the hottest month with mean maximum temperature of 27.7 �C and July is the coldest month with a maximum of 11.1 �C. Rainfall in the area ranges from 37.5 to 66.0 mm monthly average in June and October respectively. The main tree species in the study area were Eucalyptus pauciflora, E. melliodora and E. mannifera. Furthermore, Poa labillardieri, P. sieberiana, Themeda australis, Danthonia penicillata and Microlaena stipoides were the most abundant pasture species on the experimental plots. Species of clover (Trifolium spp.) were also abundant among the herbs. This study used pasture assessment techniques to quantify the effects of remnant patches of Eucalyptus open woodlands on the composition, quality and biomass production of herbaceous understorey vegetation. Microclimate and soil nutrients were also compared under trees and in the open. In addition, consumption by vertebrate grazers under Eucalyptus trees and in the open was compared. Tree density and basal area were compared with herbage standing crop. Remnant patches of Eucalyptus open woodlands modify the microclimate by reducing wind reaching the understorey vegetation. However no significant effects on ambient air temperature and relative humidity were recorded. The effect of trees on soil moisture was contingent to differences between the four sites and soil depth. Despite a 13% higher soil organic matter in the top 15 cm of soil under trees, soil total nitrogen and total phosphorus did not differ from that in the open. Surface soil pH values were lower (by 0.2 units) under the trees. No significant effect of trees on pasture species richness was found. However the classification of quadrats on the basis of species presence showed a distinction between species composition under trees and in the open at one of the four sites. vi The contribution of pasture species to total dry weight on plots under trees and in the open did depend on the particular species involved and was also contingent to differences between sites. However at the sites where Vulpia bromoides and Poa sieberiana were abundant, the two species dominated the biomass under trees. Whereas Microlaena stipoides var. stipoides dominated the biomass under trees at two sites and in the open at only one of the four sites. Pasture total N content differed between sites. Two of the sites had significantly higher (5.9% and 19.7%) N content under trees. On the contrary, pastures at one site contained 18.7% higher N content in the open. The total P content was 18% higher in pastures under trees. Overall, the pasture standing crop under trees was 15% less than in the open during August to May. Vertebrate grazers consumed about the same amount of pasture under the trees and in the open at the four experimental sites.

The experiments described in this thesis were designed to assess changes in pasture dynamics (biomass and species composition of pasture) of grazing land on the Southern Tablelands of ACT and NSW, after 16 combinations of rabbit control treatments had been applied. The rabbit control performed by CSIRO Division of Wildlife and Ecology consisted of all combinations of presence-absence of Poisoning (using sodium monofluoroacetate, 1080: POIS), Ripping (ripping warrens using a tractor fitted with ripping tynes: RIP), Fumigation (pressure fumigation using chloropicrin: FUM) and repeated follow-up fumigation (using phostoxin pellets one, six and eighteen months after completion of the initial treatment: ANN). The pasture was assessed before treatments were applied, and every six months after rabbit control treatments. Treatment combinations were assigned randomly in a 24 factorial design on a total of 32 sites. There was a significant increase of pasture biomass at the RIP+ANN treatment at post-treatment sample 5. The analysis of covariance did not detect any other significant increase or decrease of pasture biomass for any rabbit control treatment, at any posttreatment sample. A significant increase of grass species occurred for the treatments of POIS+RIP+FUM, POIS and RIP+ANN for the post-treatment samples of 1, 3 and 5 respectively. There was a significant increase of thistles at the rabbit control treatments of POIS+RIP+FUM+ANN (post-treatment sample 1), RIP, ANN, RIP+FUM, RIP+FUM+ANN and POIS+RIP+FUM+ANN (post-treatment sample 3) and RIP and FUM+ANN (post-treatment sample 5). A significant increase of weeds occurred at FUM (post-treatment sample 3) and at FUM+ANN (post-treatment sample 5). No significant changes in the amount of herbs or legumes was apparent for any rabbit control treatment or post-treatment sample. There were no significant decreases for any species group. Except for the significant results for post-treatment sample 1, all significant increases of biomass for any species group occurred during spring (post-treatment sample 3 and 5) which suggests a growth phase during spring then subsequent dieback (particularly for thistles and weeds), as any change was not detected in the following autumn sample. No strong trend is evident for any particular rabbit control treatments, or any combination of treatments. Analysis of covariance revealed that the rabbit control treatment of RIP+ANN showed significant increases in both total biomass of pasture and grass biomass during post-treatment sample 5. This treatment reduced the number of active entrances the most. Significant positive correlations were found between pasture biomass (total) with grass, herb, legume, thistle and weed species groups. Significant negative correlations between grass biomass and the number of active entrances were found when the rabbit control had been highly effective in reducing the number of active entrances. When rabbit control had not been very successful, there was a significant positive but low correlation with the number of active entrances. There was no significant relationship between the number of active entrances with the weight of rabbit dung pellets. It is reasoned that they are different measures of rabbit abundance. More rabbit dung pellets were found closer to the warren than further away from the warren, but there was no correlation between rabbit dung and pasture biomass. Rainfall was above average for most of the experiment, biomass increased accordingly, and rabbit control was highly successful. The resulting changes in the pasture were difficult to detect, although some increases in species composition groups occurred. It is reasoned that the changes observed are partly attributable to seasonal conditions, and to high rainfall. Grazing by domestic animals, sheep and cattle, had been found to be consistent throughout the experiment.

Doctor of Philosophy(PhD)
The European red fox (Vulpes vulpes L.) is a well known predator of native species and domestic stock, and is recognised as one of Australia’s most devastating vertebrate pests. Current fox management relies heavily on poisoning using baits impregnated with sodium monofluoroacetate (1080). This reliance on 1080 is likely to continue given the lack of viable alternatives for controlling foxes, so that, in the meanwhile, it is important to improve the efficiency of the current techniques. Factors affecting the susceptibility of individual foxes to bait include their ability to locate it, as well as the bait’s palatability and toxicity. The economic costs associated with using different bait types, the pattern and density of their distribution will also affect the efficiency of control programs. It is essential to examine and refine all such issues to ensure efficient use of the 1080 baiting technique. This thesis focuses generally on problems associated with management of the fox in eastern Australia. More specifically, I investigate the factors affecting the efficiency of fox baiting practices on the central tablelands of New South Wales. The study was conducted largely on agricultural lands near the town of Molong (33010’ 37”S, 148087’15”E) on the central tablelands of New South Wales. This area was chosen as it is broadly representative, in terms of land use, of a large region of eastern Australia. The highly modified, predominantly agricultural landscapes near Molong are well suited to foxes, and conflict with the predominantly pastoral community means that fox management is widely undertaken. I determined the persistence of 1080 in two commonly used bait types, Foxoff® and chicken wingettes, under different climatic and rainfall conditions. The rate of 1080 degradation did not change significantly between the central tablelands and the relatively hotter and drier western slopes. Foxoff® baits remained lethal for longer than wingettes under all conditions, although their rate of degradation generally increased with increasing rainfall. I confirmed the presence of defluorinating micro-organisms in thesoils of eastern Australia for the first time, and suggest that, following removal from the bait, 1080 would not persist in the environment for long. Bait should be attractive and highly palatable to ensure that the target species will find and consume it upon discovery. Caching, where discovered food is removed but not immediately consumed, may potentially reduce the efficacy and cost-effectiveness of baiting campaigns. I quantified the caching of chicken wingette, day-old chick and Foxoff® baits by inserting transmitters into bait material and assessing whether it was eaten or cached following removal. The intensity of caching did not change significantly between seasons. Type of bait had the largest influence on caching intensity, with a greater percentage of non-toxic Foxoff® baits (66.9%) being cached than either wingettes (5.7%) or day-old chicks (4.5%). The percentage of toxic (1080) baits cached was even greater, suggesting that 1080 bait may be less palatable, and detectable to foxes. I also investigated the use of conditioned taste aversion to reduce multiple bait uptake by foxes. Levamisole, an illness-inducing chemical, was added to bait and the fate of removed bait was again monitored via radio-telemetry. Following consumption of a levamisole-treated bait, foxes avoided eating treated baits but consumed untreated baits. I concluded that a reduction in bait consumption was achieved through learned aversion to levamisole rather than via conditioned taste aversion to baits. Adding levamisole to baits, especially non-toxic bait such as rabies vaccines, could potentially be used to reduce bait monopolisation by individual foxes. Fox density and den site preferences were assessed by investigating the distribution and density of fox natal dens on one property (9.6 km2) over three consecutive years. A total of 9 natal dens were located in 2000 and 2001, declining to 6 in 2002. No preference was shown for den sites on the basis of habitat, slope or aspect, but more dens were located under, or adjacent to cover. Assuming that each natal den represents a breeding pair and that the population sex ratio did not differ from parity (1:1), the site contained a prebreeding density of 1.9 foxes/km2 in 2000 and 2001, and 1.25 foxes/km2 in 2002. Given that the mean number of cubs is 4.0, the post-breeding density was estimated at 5.6 and 3.75 foxes/km2 in 2000/2001 and 2002, respectively. The results demonstrated that high densities of foxes occur on agricultural lands. The success and likely accuracy of the technique to monitor fox density suggests that it may be used to calibrate more efficient abundance estimates that will be essential for the strategic management of foxes in future. Pest animal management strategies are traditionally assessed for their effectiveness, with less consideration being given to the efficiency or cost of achieving the desired effect. I used cost-effectiveness analyses to compare between different baiting strategies based on the longevity, palatability and handling/replacement costs associated with each bait type. The results indicated that, when measured on a total cost-per-bait-consumed basis, wingettes and day-old chicks were the most cost-effective baits for campaigns of up to 4 weeks duration. This demonstrates the importance of including the longevity, and particularly the palatability of bait, when assessing cost-effectiveness. However, it is recognised that other factors, including the consistency of dosage and uptake by nontarget species, may be equally or more important in deciding the appropriate baiting strategy. The spatial and temporal application of fox baiting in the region overseen by the Molong Rural Lands Protection Board was examined between January 1998 and December 2002 as a case study to evaluate the apparent effectiveness of cooperative management practices. Most landholders (78.8%) did not bait for foxes during this period. Based on known dispersal distances, the effect of fox immigration into baited areas was determined. The results indicated that no areas baited for foxes were separated by a sufficient buffer distance (>9.58 km) from unbaited areas to be protected from fox immigration. This suggests that, at current levels of coordination, the effectiveness of most baiting operations in eastern Australia is compromised over the long term by fox immigration. However, it is recognised that short-term reductions in fox density may sometimes be all that are required to reduce predation to acceptable levels, especially for seasonally-susceptible prey. Ultimately, the cost-effectiveness of control should be evaluated in terms of the response of the prey rather than that of the predator. This study has highlighted deficiencies in current ‘best-practice’ baiting techniques. Specific recommendations for current baiting practices, in addition to future research, are also given. In brief, these include minimising free-feed baiting, increasing the minimum distance between bait stations, and, where possible, presenting the most palatable bait. Continued research into conditioned taste aversion, aerial baiting, and techniques to reduce caching are recommended as potential techniques to improve the efficiency of baiting practices.

The red fox occurs across a very broad range of habitats, and displays great behavioural flexibility under different environmental conditions. In Australia, mounting concern over the impacts of foxes on livestock and native fauna has highlighted a need for more information on fox ecology under Australian conditions as a fundamental step towards developing more strategic means of managing foxes. This study explores ranging behaviour, dispersal, use of dens, activity rhythms, population dynamics and diet in the absence of management in productive agricultural land in the central tablelands of New South Wales. The study was conducted from June 1994 to June 1997 on private property near Murringo, NSW Australia (34°15� S, 148°30� E). The site was primarily sheep and cattle grazing land and had a history of no fox management. Rainfall was considerably below average for much of the study. A total of 83 foxes were trapped over 3931 trapnights, of which 50 were fitted with radio-collars (23 adult and 6 juvenile females, 12 adult and 9 juvenile males) and 26 released with eartags only (all juveniles: 10 females, 16 males). Thirty-three foxes were radio-tracked using fixed towers between March 1995 and December 1996, with between 11 and 28 foxes tracked at any time. Mean home range size was 446.1 ha ± 69.8 se using 95% Minimum Convex Polygons (MCP), and 276.4 ha ± 36.3 se using 95% kernel utilisation distributions. Male home ranges defined by MCP were significantly larger than female ranges, but no significant difference was found using 95% kernels. Core ranges were estimated to be 133.4 ha ± 23.7 se using 50% MCP and 59.8 ha ± 6.1 se using 95% kernels, with no significant difference between sexes. No significant differences were found between range sizes of adults and juveniles or between years or seasons. While most home ranges were steady for the duration of the study, some foxes were observed to shift range location and 4 foxes displayed nomadic behaviour for at least some of the study. There was a high incidence of overlapping home ranges, most commonly between females or males and females but occasionally between males, but core areas were usually separate. Fully overlapping core areas were observed in 1995 but not in 1996. Juvenile foxes were significantly more likely to disperse than adults, and usually travelled further (juveniles 61.1 km 31.6 ± se; adults 5.9 km 1.1 ± se). Males and females were equally likely to disperse, and there was no significant difference in the distance travelled. The furthest distances were 285 km and 140 km, but mean distance of dispersal excluding these animals was 12.3 km ± 4.3 se (n = 13). Thorough surveys across a 16.4 km² area located 200 dens, with 68 of these active in 1995 and 96 active in 1996. Density of breeding foxes was estimated to be 0.55 and 0.52 adult foxes/km² in 1995 and 1996 respectively based on natal den counts. Density estimates based on active den counts, which include non-breeding foxes, were 0.91and 1.30 foxes/km² in 1995 and 1996 respectively. These estimates appear lower than other studies in similar habitats but this is likely due to using a half home range boundary strip around the surveyed area in the present study. Application of mark-recapture analysis found very high �recapture� rates of dens and gave a similar estimate of the total number of dens to that observed directly. Natal dens were regularly distributed across the study area, whereas active dens tended to be in clusters. There was a high turnover of which dens were used each year, but the total number of natal dens was similar across years (16 in 1995 and 17 in 1996). Natal dens were more likely to be used on repeat occasions than other dens, but not necessarily by the same vixen. Litter size based on sightings of emergent cubs was 2.8. Foxes were predominantly nocturnal, with a major peak in activity about an hour after sunset. A new method of analysing activity rhythm data using Fourier series to mathematically describe animal movements was developed, that allowed systematic identification of the cyclical components underlying overall movement patterns. General fox behaviour could be clearly described by a 24-hour and a 12-hour cyclical component when corrected for variation in daylength. The rising and setting of the sun appeared to be a major trigger underlying movement patterns. Seasonal and sex differences were observed in patterns of activity. The annual rate of increase of the fox population was found to vary around a mean of zero between June 1994 and June 1997. A major drop in fox numbers as estimated by spotlight counts occurred in the second half of 1995, but numbers recovered by the end of 1996. Kaplan-Meier analysis of radio-tagged foxes found annual adult survival was generally very high (0.56-0.96) with lowest survival between July and October. Causes of mortality were human-related outside the site and apparently of natural causes within the site. However foxes dying of natural causes outside the site were unlikely to be found. There was no overall movement of foxes into or out of the site. Immigration was detected following the drop in fox numbers in late 1995, but there was no evidence of immigration prior to this period although emigration occurred. A sensitivity analysis was conducted on the effects of a small change in life history parameters on finite rate of increase using published data as well as adult mortality data from the present study. The two most influential life-history parameters were adult and juvenile survival, while changes in fecundity and age at first reproduction had much less impact on finite rate of increase. In terms of management, in which fertility control is being considered as an alternative to lethal control, this implies that a small change in fecundity may cause less change in the rate of increase of foxes than lethal control. Foxes were culled in June 1997 on completion of the study. Estimated density using a Petersen estimate was 2.4-5.3 foxes/km² and index-manipulation-index was 1.4-3.2 foxes/km². The different methods used to cull foxes appeared to target different age groups within the population, and were generally biased in favour of younger foxes. Success at killing animals was low, leading to large standard errors in the population estimates. Stomachs of foxes shot in the Orange district were found to contain predominantly rabbit and carrion, with invertebrates present when abundant. These findings were not strictly representative of the diet of foxes in the study area, where rabbits were scarce. Foxes scavenged heavily on lamb carcasses within the study site. The quantity of fresh lamb carrion removed from a lambing paddock in winter 1996 was estimated to support 13-24 foxes, with available fresh lamb theoretically able to support 240-440 foxes. Density based on removal of fresh carcasses was estimated to be 0.83-1.5 foxes/km².

The decline and extinction of amphibian species over the past three decades is widely acknowledged as one of the greatest biodiversity crises of modem time. Providing convincing data to support hypotheses about these declines has proved difficult, which has greatly restricted the development and implementation of management actions that may prevent further amphibian declines and extinctions from occurring. In this thesis, I present research that was undertaken as part of the recovery programs for the southern corroboree frog (Pseudophryne corroboree), and the Booroolong frog (Litoria booroolongensis); two species that underwent very rapid declines in distribution and abundance during the 1980's. More specifically, I investigated potential causal factors in the declines of both species using experimental and correlative studies, and examined the mechanisms by which one threatening process (chytridiomycosis) may be causing continued decline and extinction in P. corroboree. I also examined the implications of population dynamics for monitoring L. booroolongensis, and suggest a possible monitoring strategy that may reliably facilitate the implementation of recovery objectives for this species. I also tested one possible reintroduction technique aimed at preventing the continued decline and extinction of P. corroboree populations. In Chapters 2 and 3, I present the results from a series of experiments in artificial enclosures designed to examine whether the tadpoles of L. booroolongensis are susceptible to predation by co-occurring introduced predatory fish species; brown trout (Salmo trutta), rainbow trout (Oncorhynchus mykiss), European carp (Cyprinus carpio), redfin perch (Percafluviatilis), and mosquito fish (Gambusia holbrooki). I demonstrated that the tadpoles of L. booroolongensis, and a closely related species Litoria lesueuri, were palatable to non-native trout species, but not to two native predatory fish species, Gadopsis bispinosus and Galaxias olidus. A pond breeding frog species included in this experiment, Limnodynastes tasmaniensis, was palatable to both the native and non-native fish species. In a separate experiment I also demonstrated that the tadpole of L. booroolongensis is palatable to the three other introduced fish species examined in this study; C. carpio, P. fluviatilis, and G. holbrooki. In three of the experiments, the provision of rock within enclosures as a potential refuge habitat did not afford protection to L. booroolongensis tadpoles from predation by any of the five introduced fish species examined. While all the introduced fish species tested here did consume L. booroolongensis tadpoles, the results also suggested that chemical unpalatability might afford some level of protection against some of these fish species. Firstly, the addition of alternative prey items in one of the experiments reduced the proportion of tadpoles consumed, suggesting that L. booroolongensis may not be a preferred prey item. Secondly, the proportion of tadpoles consumed varied greatly among the different fish species examined, suggesting differing levels of palatability. Overall, this study supports previous research in suggesting that chemical unpalatability may be an important strategy for the tadpoles of riverine frog species in south-eastern Australia to avoid predation by native fish species, and that this strategy is less effective against introduced fish species. While L. booroolongensis currently persists in streams inhabited by a number of introduced fish species, this study supports the likelihood that these species are having a negative impact on populations of L. booroolongensis in the wild. In Chapter 4, I present the results of a study aimed at examining potential monitoring techniques for L. booroolongensis. The results of a mark-recapture exercise demonstrated that L. booroolongensis may exhibit large fluctuations in abundance from one year to the next, and through a prospective power analysis approach, I demonstrated that it would be difficult to confidently identify population trends of interest using either indices or estimates of abundance for this species. An assessment of the capacity to identify the presence or absence of L. booroolongensis using nighttime spotlight surveys demonstrated the high detectability of this species using this technique, at both the scale of 300-meter sections of stream and individual breeding areas (typically less than 10-meters of stream). This study suggests that the monitoring objectives of the L. booroolongensis recovery program would be most effectively achieved using presence/absence surveys at different scales. In Chapter 5, I present the results of a field survey aimed at determining the current distribution and habitat requirements of L. booroolongensis in the South West Slopes region of New South Wales. Of the 163 sites I surveyed across 49 streams,I located L. booroolongensis along 77 of these sites from 27 streams. Based on population and habitat connectivity, this study identified 18 populations of L. booroolongensis that are likely to be operating as independent populations. Twelve of these populations are not represented in conservation reserves, but rather occur along streams that flow through the agricultural landscape. A broad scale habitat analysis identified a positive relationship between extent of rock structures along the stream and the occurrence of L. booroolongensis, and a negative relationship between the proportion of canopy cover and this species' occurrence. At the breeding habitat scale, this study identified a positive relationship between the presence of breeding males and; number of rock crevices in the aquatic environment, extent of emergent rocks, and proportion pool. This analysis also detected a negative relationship between occupancy and water depth. These results confirm previous work suggesting the importance of rocky stream habitats to the persistence of L. booroolongensis, but also suggest how disturbance processes, such as increasing sedimentation and weed invasion, may reduce the suitability of rocky structures as breeding sites. In Chapter 6, I investigated current levels of amphibian chytrid fungus (Batrachochytrium dendrobatidis) infection in corroboree frog populations, and used retrospective screening of museum specimens to assess the possibility that this pathogen was implicated in the initial decline of the corroboree frogs. Using histology, I did not detect any B. dendrobatidis infections in corroboree frog populations prior to their decline, however using the same technique, moderate levels of infection were detected in post-decline populations of both species. Real-time PCR screening of skin swabs identified much higher overall infection rates in post-decline populations of P. corroboree (between 44% and 59%), while significantly lower rates of infection were observed in P. pengilleyi populations (14%). These results suggest that the initial and continued decline of the corroboree frogs may well be attributed to the emergence of B. dendrobatidis in populations of these species. In Chapter 7, I investigated how B. dendrobatidis may be causing the continued decline of P. corroboree through the presence of an abundant reservoir host for this pathogen. I found that populations of adult C. signifera in sub-alpine bogs carry high B. dendrobatidis infection rates (86%), but appear unaffected by this infection. An experiment involving the release of P. corroboree tadpoles into 15 natural pools resulted in metamorphs from seven of these pools testing positive for B. dendrobatidis, with all these individuals dying soon after metamorphosis. These results support the possibility that B. dendrobatidis infection in P. corroboree populations is being facilitated by the presence of large numbers of infected C. signifera in the shared environment. Chapter 8 presents the results of a population augmentation study for P. corroboree. I investigated the extent to which increasing recruitment to metamorphosis may result in population recovery in this species. This was undertaken by harvesting eggs from the field and rearing them through to mid stage tadpoles over the winter period prior to being released back to their natal ponds in spring. While I was able to increase recruitment to metamorphosis by an average of 20 percent, this did not result in a noticeable influence on the subsequent adult population size, as both manipulated and non-manipulated sites declined over the course of this study by an average of 80 percent. I observed a positive relationship between natural recruitment to a late tadpole stage and subsequent adult male population size, however there was considerable variation associated with this relationship. The relationship between recruitment and subsequent population size at the augmentation sites was consistent with the relationship observed at the non-manipulated sites. These results suggest that recruitment to metamorphosis may not be the most important life stage restricting the population recovery of P. corroboree, but that mortality during post-metamorphic stages may be more important in regulating current population size. Hence, further attempts to use captive rearing to increase P. corroboree populations in the wild should focus on the release of post-metamorphic frogs. Overall, this thesis demonstrates the value of quantitative research to the implementation and progress of threatened species recovery programs. While this research will specifically contribute to the recovery programs for L. booroolongensis and P. corroboree, it more broadly contributes to the understanding and capacity to respond to the concerning levels of amphibian extinctions currently occurring throughout the world.

The Monaro Volcanic Province (MVP) is an Oligocene-Eocene intraplate basaltic lava field situated in the Southern Highlands of New South Wales between the towns of Cooma and Bombala. The lava pile of the MVP consists of basal sub-alkali rocks (olivine tholeiite, transitional basalt) capped by a number of thick ankaramite lavas, above which lie less numerous alkali rocks including alkali olivine basalt, nepheline basanite and olivine nephelinite. Intercalated with the lava flows are massive and matrix-supported alkali and ankaramitic hyaloclastites, alkali pillow basalts, rare tuffs, bauxitic weathering profiles, lacustrine sediments and reworked late Cretaceous to early Tertiary river gravels. The lava pile is intruded through by numerous volcanic plugs and dykes and rare maars. Volcanic centres are principally concentrated in two NW-SE trending zones parallel to major crustal-scale fractures in the Palaeozoic basement. Centres almost always lie over the intersections of two or more conjugate strike-slip or transverse fractures. The stratigraphy, whole-rock geochemistry and Sr and Nd isotopic signatures of rocks from the MVP indicate magma-genesis initially from an asthenospheric source with EM1 characteristics, gradually becoming more lithospheric with DM source characteristics. The long-lived nature of the MVP rules out a mantle plume-type source for magmas. Instead, a diapiric source is envisaged. The MVP mantle xenolith suite appears to have equilibrated at slightly higher temperatures for given pressures than the Newer Volcanics Province suite suggesting the palaeogeotherm for the MVP was slightly hotter than the "South East Australian" geotherm. Large amounts of amphibole (pargasitic hornblende, pargasite, ferroan pargasite and kaersutite) occuring within the more silica-undersaturated rocks of the MVP, and rarely within Iherzolitic xenoliths, are interpreted to have formed as selvages on mantle veins in contact with peridotite beneath the MVP. Amphiboles were later sampled by magmas rising through the same conduits and were brought to the surface. MVP ankaramite lavas feature < 2cm clinopyroxene porphyrocrysts, the cores of which are shown to have crystallised at ca. 18 kb pressure or ca. 54 km depth. This defines the base of the local crust within the MVP region. Data from the MVP support a landscape evolution model based on the isostatic rise of the Southern Highlands due to voluminous magmatic underplating since the Cretaceous. Data further support limited denudation since the Early Tertiary based on a pulsatory but high palaeogeotherm.

Food webs, defined as "who eats whom" in nature, have become a central topic within community ecology and thus they have been used to understand general ecological patterns such as biodiversity and species interactions as well as material and nutrient flows within ecosystems. In South America the knowledge of the taxonomy and distribution of freshwater invertebrates is incomplete and fragmented. Previous studies have focused on specific taxonomic groups and some countries such as Brazil and Argentina. In contrast, there have been many aquatic food webs published for UK freshwater systems with high levels of taxonomic resolution. This thesis aims to examine food web patterns in two geographically separated systems. The effects of systematic taxonomic aggregation on food web properties were examined and the relationship between consumer and prey body size revisited. A total of 24 food webs were examined in Chilean and Welsh streams, where 6128 invertebrate guts were examined to establish feeding interactions. These Chilean and Welsh food webs are amongst the largest, most complete and fully resolved. In both systems there was a high proportion of basal species, combined with low proportions of top and intermediate species. Significant differences were detected in most food web properties, in comparison to previous studies, where basal species were aggregated to coarser categories. No significant relationship between the body size of the consumers and their prey was found in either Chilean or Welsh streams. These results differ substantially from published data, and we attribute these differences to the greater taxonomic resolution particularly on the basal resources.

Rhizophora stylosa is a common and widespread mangrove species on tropical coasts in the Indo-West Pacific and very common and widespread in northern Australia. This aim of this study was to investigate R. stylosa's distribution, growth, reproduction and population genetics over the last 300 kms of its range at its southern limits in northern New South Wales on the Australian east coast. Rhizophora stylosa was found to be more widespread between and within estuaries in northern New South Wales than previously recorded, with evident spread over recent decades. A new southern limit of South West Rocks Creek was determined, with only two mature trees are present. Rhizophora stylosa is in small numbers in most the 16 estuaries now known to contain R. stylosa in NSW. Its distribution is illustrated from intra-estuarine scales in small 'incipient' stands developing within estuaries to the colonisation of new estuaries. Despite the evidence of recent population spread, several restricted old stands were recorded, indicating a limited presence of R. stylosa at high latitudes for much longer periods, somewhat complicating a simple model of expanding range with recently warming climate. Mangrove species are generally understood to be limited by cold, but significant provisos on ascribing R. stylosa's recent spread to the warming trends of the last several decades exist. A shoot tracking methodology was applied for 2.5 years in three estuaries, including the most southerly, and detected little if any reduction of growth over a range of 260 km. Rhizophora stylosa has a reiterative mode of growth and an average of three leaf emergences (6 leaves) per annum was found. The growth results overall are comparable to some tropical studies, particularly if herbivory is accounted for, and R. stylosa appears not to be at its thermal tolerance at its known southern limits.;Leaf longevity was greater than comparable tropical studies, suggesting the trees were compensating for climatic factors in this manner. A reproductive study conducted at the same time on the same shoots found trees reproduce successfully even at the southern limits, with little or no evidence of a decline with latitude across the study area. Only a small proportion of buds finally form propagules (overall 2.2%), but again fecundity is comparable to tropical studies, although the full reproductive cycle from flower bud primordia to viviparous propagule may be slightly longer. A generally low level of genetic diversity measured as allelic richness and heterozygosity and evidence of inbreeding was detected during the genetic study on samples from eight New South Wales estuaries, three localities in Moreton Bay and eight localities in north Queensland. Spatially, the New South Wales and Moreton Bay localities are from one pool, but there is differentiation between localities and little geographic coherence along the coast. Different origins and histories are likely for the estuaries, supporting a hypothesis arising from the distribution of R. stylosa in New South Wales that colonisation from the ocean has been and continues to be sporadic on the northern New South Wales coast. The major variation in the genetic data is between North Queensland and the southern localities, as expected, although relatedness remains, raising interesting biogeographic questions on current or recently historic gene flow between distant populations. Many questions remain about R. stylosa at the ends of its range, but there are indications that it is well within its tolerance ranges in northern New South Wales, perhaps contrary to some expectations of a mangrove species at its southern limits.

The mechanisms of denudation over the last 25,000 yrs are studied for Wangrah Creek, a headwater drainage basin of the Murrumbidgee River, N.S.W. The controls on denudation of climate, humans, and autonomous geomorphic change, are then resolved for different times in the past, by comparison with independent palaeoenvironmental data. The study also puts the history of the basin since settlement, 150 yrs ago, in it's longer term context. The stratigraphy of alluvial and colluvial deposits is investigated together with monitoring of streamflow, slope runoff and sediment yield. Historical changes to denudation are analysed from maps, air photographs and the most recent deposits. Extensive radiocarbon dating of deposits is included. The stratigraphy and morphology of Limekiln Creek, a tributary valley within the larger basin, allows modes of deposition to be attributed to certain lithologies. In particular, mildly organic, fine grained alluvium is associated with swampy meadows. These are valley floors with no continuous channel, a permanently saturated surface, and a dense vegetation of sedges and grasses. Planar bedded sands and gravels, deposited across the valley floor, are associated with discontinuous gullies. There was a period of rapid hillslope erosion in Wangrah Creek between 20,000 and 25,000 yrs BP. This left thick deposits in all valleys. A period of intense valley erosion removed the Pleistocene deposits from the main valleys and started incision of smaller valleys. The reworking of Pleistocene deposits became the dominant source of sediment in swampy meadows and small alluvial fans throughout the Holocene. Surface wash and gully extension were the mechanisms of erosion. Pleistocene deposits were the dominant source of sediment because of very low amounts of runoff from slopes. Impermeable sub-soils probably caused greater runoff from Pleistocene deposits. The Holocene was a period of low denudation rates, of the order of 1 mm of ground lowering per 1,000 years, averaged across the basin. Three times during the Holocene, as swampy meadows spread up valleys, intrinsically unstable conditions developed and a short period of gully erosion ensued. Monitoring of streamflow, and a simple hydrological model indicate that as swampy meadows expanded, runoff from moderate sized storms increased and small channels developed in the valley. The small channels are believed to promote gully initiation during large floods. Gullies started to infill once swampy meadows developed on the gully floor. Sediment delivery downstream then decreased to very low levels. Environmental changes during the Holocene had no effect on mechanisms of denudation and little effect on rates of denudation. With European settlement, gully erosion became more widespread than since the Pleistocene, although many gullies have now stabilised. In Wangrah Creek, gully erosion after settlement was initiated by different mechanisms than during the Holocene, and was probably the result of site-specific disturbances to the valley floor. Monitoring of erosion since a fire, coupled with the stratigraphic study, show that mild bushfires, whether anthropogenic or natural, will not accelerate erosion in Wangrah Creek. Aboriginal burning of the landscape in the late Holocene had little effect on denudation.

An investigation of the geological resources of the Southern Highlands was undertaken and over two hundred samples were collected and examined for possible use as stoneware ceramic ingredients. Thirty four of these samples were tested for possible use as clay body ingredients, while sixty five samples were selected for assessment as glaze ingredients. A wood fired kiln was built from firebricks produced from a local deposit of a white bauxite related material. Materials selected as a result of these tests were combined to create ceramic objects fired at stoneware temperatures. The most interesting result of the investigation was the discovery of a number of small weathered dykes and sills, samples from which were developed into workable ceramic clay bodies and glazes using a simple empirical testing procedure. A previously unknown excellent white translucent native porcelain stone or ‘bai tunze’ was discovered and developed into a workable porcelain body. Some iron stained porcelain bodies that ‘flashed’ red in the wood firing kiln were also developed. Exhibitions of the creative work produced were shown in the ‘Legge Gallery’, a Fine Art gallery in Sydney. Two critical reviews of those shows appeared in the magazine Craft Arts International, No. 64, 2005, pp 106-107 and The Journal of Australian Ceramics, Vol 46 #1 pp 21-24. Several papers were published detailing various aspects of the research: “The Search for Raw Materials in the Southern Highlands” in The Journal of Australian Ceramics, Vol 41#3, pp 22-23; “Flotation – A method of refining useful minerals”, in The Journal of Australian Ceramics, Vol 41#3, pp 24-25; “Magic Dirt” in The Journal of Australian Ceramics, Vol 46 #1 pp 76-79; “New work from an old landscape”, in Ceramics Technical, 24, 2007. pp 45-52;“From the ground up”, in Ceramic review, issue 222, 2006, pp 54-55. The research concludes that the Southern Highlands of New South Wales is geologically rich in suitable materials for the production of stoneware ceramics and that there are a few specific bai tunze like materials that are very interesting and have considerable aesthetic potential. The research determined that these bai tunze like materials are potentially capable of being developed into clay bodies and glazes of great beauty.
Doctor of Philosophy (PhD)

This thesis concerns a sedimentological study of the Late Permian Broughton, Pheasants Nest and Erins Vale Formations, southern Sydney Basin, New South Wales, aimed at producing a palaeoenvironmental interpretation of these sequences. It is based on facies analysis of borecore data, vertical and lateral profiling of outcrop sequences, including architectural element analysis, and an integration of the results of these studies with previous work. The sequences studied begin with the interdigitating lower offshore silt of the upper Berry Siltstone and lower offshore sand-belt of the lower Broughton Formation, including progradational volcanic shoreface sequences. Sedimentation occurred in the 'Broughton Seaway' between the western cratonic landmass and a north-northeast oriented volcanic barrier in the east. River-derived meltwater underflows, massflows, tidally-driven longshore currents and migration of large sandwaves into the lower offshore sand-belt were the major depositional processes. The upper offshore sand-sheets of the middle Broughton Formation represent a widespread development of time-transgressive, above storm wave base, aggradational sedimentation. The progradational sandskirts of volcanic alluvial fans in the south (Jamberoo Sandstone Member) constructed a delta which was of a mixed type between a pyroclastic and alluvial fan delta. These kinds of deltas probably served as significant sources and depositional conduits for the offshore sediments which were dispersed mainly through wave action in a storm-dominated setting._ Submarine volcanic flows and associated shallow marine environments, and emerged volcanic islands with woodlands were coevally present in the southeast during the deposition of the Broughton Formation. The upper Broughton Formation is generally marked by a northeastward diachronous progradation of the southern shoreline, which progressively filled up the Broughton Seaway. Progradational evolution of the deltaic to barred shoreline, reflecting waning influence of the Gerringong volcanic barriers, was contemporaneous with the upper deltaic and distributary coastal zone sedimentation of the Pheasants Nest Formation. Actually, the periglacial braided subaerial fans and subaerial volcanism modelled for the lower and middle Pheasants Nest Formation greatly contributed to a northward progradation of the shoreline and retreat of the Broughton Seaway. With additional contributions from the western craton, a centripetal sediment transport pattern toward a northeast-oriented depocentre resulted. This meant development of a northeasterly flowing longitudinal drainage system. Physiographically, most of the former Broughton Seaway had now transformed into a broad valley between the volcanic and cratonic hinterlands. During the upper Pheasants Nest Formation time, extensive development of a flat, alluvial plain with an axial drainage pattern, low-lying coastal swamps and networks of high sinuosity, single channel or multiple channel anastomosing river systems is postulated. A shallow epeiric Erins Vale sea was caused by transgression across the topographically low-lying northeastern to northern alluvial plains of the Pheasants Nest Formation . The lower-middle Erins Vale Formation represents shoreface-offshore conditions in the east and north, including an oxygen-deficient, lower offshore regime (Kulnura Marine Tongue) - and shoreline fades of a transgressive barrier system in the west and south. Deposition during the upper Erins Vale Formation occurred through fan delta progradation from the western craton, which passed upward into the subaerial fan of the Marangaroo Conglomerate; a central and southern regressive barrier system and an energetic shoreface sand in the east which passed upward into the Wilton Formation. The upper Nowra Sandstone and lower Berry Siltstone form a transgressive systems tract. A sustained tectonic loading producing protracted subsidence was apparently the primary cause of basin subsidence. The upper Berry Siltstone and lower to middle Broughton Formation represent an overall highstand systems tract with portions of the upper Berry Siltstone and the lowest Broughton Formation showing interludes of minor transgressive pulses. This reflected a more stabilized base-level situation, following a reduction of basin subsidence rate. The upper Broughton Formation and lower-middle Pheasants Nest Formation constitute a lowstand systems tract, including early regressive phases represented by the upper Broughton Formation. It was related to the development of a foreswell on the basin margin and subsidence in the depocentre caused by the propagation of compressional energy from the orogen. The upper Pheasants Nest Formation indicates an early transgressive stage and the lower Erins Vale Formation, including the Kulnura Marine Tongue, is a transgressive systems tract. The middle Erins Vale Formation represents a highstand systems tract. Subsequently, the early regressive phases represented by the upper Erins Vale Formation, the lowstand wedge of the basal Wilton Formation and the Marangaroo Conglomerate constituted a lowstand systems tract. They developed as a result of erosion of a fores well produced on the cratonic margin. This study provides evidence in support of the Currarong Orogen. The Offshore Uplift is probably a preserved portion of the Currarong Orogen and the Newcastle Sub-basin was a likely depocentre for the Late Permian sequences. A periglacial climate with seasonal freezing and thawing had significant influence on sedimentation. Episodic meltwater discharge mobilized large volumes of volcaniclastic materials in spring (as lahars at times of large floods and/ or volcanic eruptions) and associated ice floes enroute to the sea. The major variables for the studied sequences in the southern Sydney Basin are constrained in this thesis, and comparative studies identified modern and ancient global examples that are broadly similar to the Late Permian sequences.

"Two independent geochronological techniques specifically targeting post-kinematic or late-stage growth of kyanite, staurolite and late-stage garnet in the southern Curnamona Province has found that these minerals grew during the Delamerian Orogeny (~530-500 Ma). Prograde metamorphism during the Delamerian Orogeny attained kyanite-staurolite-garnet grade (amphibolite-facies). Previous interpretations of an anticlockwise P-T path for the Olarian Orogeny need revising, as these interpretations have been shown in this study to be based on textural relationships spanning ~1100 million years. This highlights the importance of in situ geochronological techniques in defining robust P-T-t paths for a region." --p. 121 of source document.
Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2006.