Dissertations / Theses on the topic 'Acclimatization (Plants) – New South Wales'

Glenbrook Lagoon, an 8 hectare lake receiving rainfall runoff from a residential catchment, is experiencing nutrient enrichment problems expressed as excessive aquatic plant presence. This study aims to assess the relative nutrient contribution of the total system compartments, including catchment loading, water column, aquatic plants and surface sediment. This information is utilised in the formulation of management strategies which may produce a sustainable nutrient reduction and general improvement in the system. The total nutrient content of the aquatic system was determined to be high in comparison with the present nutrient loading from the catchment. The ideal management case considers nutrient reduction of the surface sediment compartment firstly, followed by the aquatic plant community, with the water column and catchment influence as relatively low priority compartments. Various strategies for managing these are proposed. The total system benefits of the ideal management case are reductions in nutrients, aquatic plant biovolume and suspended solid loading. Unavoidable constraints placed upon the ideal management case include the excessive aquatic plant presence restricting accessability to the surface sediment for dredging. The resulting best management case requires aquatic plant eradication prior to sediment management, with the total system benefits associated with the ideal management case being retained.
Master of Science (Hons)

This thesis explores issues relating to the application of physiological-process models (???process models???) of forest growth to mixed species, mixed age forests, in particular the coastal blackbutt forests of New South Wales. Using a dataset provided by State Forests of New South Wales (Carter 1994 unpubl.) a numeric description of the forest was developed and stand-level parameters of interest were derived, in particular the plot by plot stemwood volume growth from 1975 to 1999. The amounts of harvested volume, volume that died and volume that grew into the measurement population were identified separately, and several different means of accounting for volume change over time were investigated. A method for quantifying the impact of harvesting and other silvicultural practices on the growth of the forest was developed and programs were written to convert the stand-level summary of the harvest impact into a semi-random selection of trees that would be ???harvested??? from the database under the set of silvicultural assumptions (Dore et al. 1999). A number of process models were investigated and reviewed before selecting one particular model, SUSTAIN (Dewar 1997) for adaption to these forests. This model is a relatively simple process model with a small number of input parameters. The model was adapted so that it could be used to compare the SUSTAIN estimate of growth with the growth of an individual stand of trees in the Kendall Forest Management Area, between Wauchope and Taree on the mid-north coast of NSW. To improve the accuracy of the prediction of growth by SUSTAIN, a method of re-setting the state of the stand to the actual condition at the time of remeasurement was developed. In addition, the SUSTAIN model was extended to enable two separate levels of canopy to be described and grown separately. Ultimately the model was only partially successful in mirroring the growth predicted by the empirical data. Its partial success is attributed primarily to the difficulties associated with correctly determining the allocation parameters used by the model to assign net photosynthate to the roots, foliage and stemwood. The nature of the change in allocation parameters when the forest stand is disturbed by harvest or fire needs further investigation.

Patterns in the floristic composition, stand structure, species richness and environmental characteristics of plant communities at a number of spatial scales were examined in Ku-ring-gai Chase National Park, New South Wales. Vegetation patterns in eastern Australia have often been related primarily to a single environmental variable, soil phosphorus concentration. This study examines the 'single nutrient' hypothesis regarding the distribution of plant species. If soil phosphorus concentration is the majot factor affecting the distribution of plant species, then this should be highly correlated with spatial patterns in the floristic composition of plant communities within the study area. Floristic composition was determined as the frequencies of all vascular species occuring within duplicate 500 m2 quadrants from fifty sites within the Park. Environmental data consisted of 21 variables, including soil physical and chemical characteristics, from each quadrant. The patterns in floristic composition and environmental factors are described and the relationships between composition and environment were examined. through indirect and direct gradient analyses. The measured environmental factors showed strong correlations with floristic patterns; however, two scales of species distributions were apparent: between and within soil type. Direct gradient analyses of composition and environmental data showed soil phosphorus concentration was inadequate in explaining the observed patterns in floristic composition of plant communities are a response to complex multivariable environmental gradients. The structural characteristics of vegetation stands were examined through the development of a multivariate approach to the classification of stand structure. This multivariate approach is essentially a modification of an existing scheme utilising foliage projective cover of various recognisable strata within the strands. Multivariate classification and ordinations of plant communities based on structural characteristics showed strong correspondence to that obtained by compositional analyses. The complex multivariable gradient hypothesis is supported from results examining stand structure-environment relationships. The relationship between species richness and richness of three growth-form types (tree, shrubs, and herbs) and environmental variables were examined through generalised linear models. The measured environmental variables showed strong relationships with species richness, consistent with the results found multivariately with floristic composition and stand structure. No single measured environmental variable adequately predicted the observed patterns in species richness, rather species richness showed strong relationships with complex multivariable environmental gradients. This study clearly demonstrates the the 'single-nutrient' or 'phosphorus' hypothesis is inadequate in explaining all the patterns in the various components of vegetation within Ku-ring-gai Chase National Park. The complex multivariable environmental gradient hypothesis suggested by the relationships between floristic composition and environmental variables is supported by the relationships exhibited by two other attributes of vegetation communities: stand structure and species richness. Further studies testing the significance of the complex multivariable environmental gradient hypothesis are required.

Lake Illawarra is a shallow barrier lagoon, located on the south-eastern coast of Australia. Eutrophication, referring to the enrichment of water by inorganic plant nutrients (primarily nitrogen and phosphorus), is one of the key environmental problems in Lake Illawarra. Management of macroalgae in Lake Illawarra is a major issue; excessive blooms of macroalgae, resulting in odours, access problems and community concern over Lake health, have led to many management strategies, including direct harvesting of algal biomass. Little information is available on the factors responsible for excessive growth of macroalgae in Lake Illawarra, although over supply of nutrients has often been cited as the primary cause. The aim of this study was to investigate the distribution, diversity, biomass and nutrient relationships of seagrasses and macroalgae in Lake Illawarra, and to determine what contribution, if any, macrophytes make to the Lake’s nutrient budget. Firstly, detailed species lists and taxonomic descriptions were prepared for macrophytes occurring in Lake Illawarra, between June 2000 and July 2003. This study focused primarily on shallow (< 1 m depth), inshore areas of Lake Illawarra, where problematic macroalgal blooms frequently occur. Seagrasses found in Lake Illawarra are Zostera capricorni, Ruppia megacarpa, Halophila ovalis and Halophila decipiens. In addition, 35 species of macroalgae were recorded and described; these included: 14 species from 7 genera of green macroalgae; 9 species from 9 different genera of brown macroalgae; and, 8 species from 8 genera of red macroalgae. The biomass of seagrasses and macroalgae in Lake Illawarra were documented seasonally (winter and summer) at four key Lake Illawarra sites; these included two R. megacarpa sites and two Z. capricorni sites. Average R. megacarpa and Z. capricorni dry weight (DW) biomasses (above and below-ground material) ranged from 54.8 - 440 g DW m 2 and 58.1 - 230 g DW m 2, respectively. Significant die-back, particularly of Z. capricorni, occurred in winter; summer biomasses were up to 1.5 - 3.9 times higher than winter biomasses. Below-ground material (roots and rhizomes) comprised 20 - 45 % and 40 - 67 % of total plant biomass for R. megacarpa and Z. capricorni, respectively. Macroalgal biomass in 2000-03 was notably lower than in previous decades; this may be due to drought, as well as improvements in water quality. Maximum biomasses of macroalgae recorded in the present study were 150 - 370 g DW m 2. Algal blooms were composed primarily of the filamentous chlorophytes, Chaetomorpha linum and Chaetomorpha billardierii. The highest seagrass (R. megacarpa) and macroalgal biomasses usually occurred at the Oasis Caravan Park site, located along the eastern Lake Illawarra peninsula. Tissue nutrient analyses were conducted on the most abundant seagrasses (Z. capricorni and R. megacarpa) and macroalgae occurring at four sites in Lake Illawarra, between spring 2000 and winter 2002. Total C contents of macrophytes varied from 23.3 - 42.0 % C for seagrasses, and 28.0 - 39.7 % C for macroalgae. The δ13C and δ15N contents of seagrasses ranged from -7.7 to 15.9 ‰ and 0.7 - 9.0 ‰, respectively. The most significant seasonal variations in seagrass δ13C contents and, to a lesser extentδ15N contents, occurred in Z. capricorni located at the source of fresh water input, Mullet Creek. Macroalgae showed a greater variation in isotopic signatures than the seagrasses, ranging from 4.9 to 19.8 ‰ (δ13C) and 1.8 - 14.6 ‰ (δ15N). Differences between species at the same site were often more significant than differences between the same species at different sites. Seagrass leaf N and P contents ranged from 1.74 - 4.13 % (mean ± s.e.: 2.62 ± 0.05 % N) and 0.12 - 0.59 % P (mean ± s.e.: 0.31 ± 0.01 % P); leaf N and P contents were typically double those of roots/rhizomes. N contents varied between species and sites, but P contents of Z. capricorni were usually significantly higher than R. megacarpa. Z. capricorni C and N contents increased in winter, corresponding to lower winter biomasses. Seagrass leaf biomass and tissue P contents peaked in summer 2002, which may be related to higher water column P concentrations in summer. Tissue N and P contents of macroalgae were more variable than those of the seagrasses, and ranged from 0.85 - 3.95 % N and 0.03 - 0.58 % P. The average C/P (808 ± 65) and N/P (47.9 ± 3.47) molar ratios of macroalgae were typically double those of the seagrasses. Low concentrations of tissue P, with respect to N, in R. megacarpa and macroalgae implied P limitation on several occasions, particularly when macrophyte biomasses were low. High tissue N contents in Lake Illawarra macrophytes suggested N limitation of biomass formation rarely occurred. Evidence of P, rather than N, limitation in macrophytes is surprising considering most data suggests N limitation of phytoplankton production in Lake Illawarra. The estimated pools of N and P contained in Lake Illawarra macrophyte biomass were similar to those present in the water column, but appeared minute when compared to the N and P stored within Lake Illawarra sediment. Laboratory culture experiments were conducted to evaluate the response of the most problematic alga, Chaetomorpha linum, to nutrient enrichment. Water temperatures of 20 - 25°C were found to promote the highest growth rates (up to 27 % WW d 1) of C. linum, but high growth rates (13 % WW d 1) were also recorded at 10°C, the lowest winter water temperature recorded in Lake Illawarra. Enrichment with N, rather than P, had the greatest effect on C. linum; growth rates were significantly reduced in treatments without added N, but treatments with N-alone were statistically similar to N+P treatments. It was concluded that in Lake Illawarra, C. linum was strongly nitrogen limited. The ability of C. linum to grow successfully in culture, under a range of nutrient treatments, and without added phosphorus, in particular, correlates with the excessive growth of this alga in Lake Illawarra. This study has made a significant contribution to the understanding of seagrass and macroalgal growth, biomass and distribution in Lake Illawarra. This information will assist with the long-term management of macroalgal problems in Lake Illawarra.

Thesis (PhD)--Macquarie University, Division of Environmental and Life Sciences, Dept. of Biological Sciences, 2005.
Bibliography: p. 178-203.
Introduction -- Study sites -- Leaf characteristics and resource availability -- Insect herbivory and resource availability -- Insect communities and resource availability -- Influence of resource availability on recovery from herbivory -- Conclusions.
This project used the resource availability hypothesis (Coley et al., 1985) as a framework for investigating the relationship between resource availability (as defined by soil nutrients), leaf traits, insect herbivore damage and insect community structure. According to the hypothesis, plants from low resource environments should be better-defended, have longer leaf lifespans and slower growth rates than plants from higher resource environments. Higher resource plant species are expected to suffer higher levels of herbivory and recover faster from herbivory than low resource plant species (Coley et al. 1985). A corollary to this hypothesis is that plants from higher resource sites should support greater densities of insect herbivores than low resource species. Comparisons between high and low resource sites were made in terms of: (i) leaf traits of mature and immature leaves; (ii) phenology of leaf maturation; (iii) herbivore damage in the field and laboratory; (iv) diversity and abundance of herbivorous insect fauna; and (v) ability to recover from herbivory.
Mode of access: World Wide Web.
243 p. ill., maps

Thesis (PhD)-- Macquarie University, Division of Environmental and Life Sciences, Dept. of Chemistry and Biomolecular Science. 2006.
Bibliography: p. 229-249.
Ch. 1. Introduction -- ch. 2. An ethnobotanical study with the Kamilaroi and Muruwari Aboriginal communities and relationship building -- ch. 3. Biological assay methods and optimisation -- ch. 4. Ethnopharmacological study of Eremophila sturtii -- ch. 5. Ethnopharmacological study of Exocarpos aphyllus -- ch. 6. General conclusions -- Appendices.
This study covered the documentation of first-hand medicinal plant knowledge of Aboriginal communities in northern New South Wales through the isolation and characterisation of bioactive compounds from Aboriginal medicinal plants.
Mode of access: World Wide Web.
xx, 249 p. col. ill., maps, ports

Masters Research - Master of Philosophy (MPhil)
Two commonly used biological water quality assessment methods in Australia are SIGNAL2 and AUSRIVAS. Both rely on taxonomic data from one macroinvertebrate sample per site to be assessed to classify water quality, and it is thought that one sample is unlikely to be adequate to reliably assess water quality in all types of fluvial system. This study set out to investigate the variability associated with these single-sample methods when applied to streams in the lower Hunter River catchment, NSW, when monitoring the impacts on water quality of discharge from sewage treatment plants. The investigation is somewhat different to previous studies using these biotic indices since no previous research has been undertaken to assess the variability of these single-sample methods for reliably assessing water quality in a particular fluvial system within a robust statistical framework. In this case, the creeks of the lower Hunter region are seasonally variable with respect to flow, have been degraded by past land use practices, have the additional load of treated effluent from wastewater treatment plants and have not previously been the subject of investigation using these methods. Hunter Water Corporation operates several inland wastewater treatment plants which discharge treated effluent into the creeks of the lower Hunter Valley, New South Wales, Australia. Currently, the water quality monitoring program involves the periodic measurement of various water quality parameters; however incorporating biological monitoring into this program would give a more holistic assessment of water quality and ecosystem health. The within-site variability of SIGNAL2 scores and AUSRIVAS OE50 values was investigated by collecting ten macroinvertebrate samples from sites upstream and downstream of the wastewater treatment plants at Cessnock, Kurri Kurri, Branxton and Farley during Spring 2002, Autumn 2003, Spring 2003 and Autumn 2004. The percentage chances of misclassifying the water quality at a particular site when using a single sample compared to a ten sample mean classification were calculated, and the consequences of this variability for impact assessments was investigated. This study demonstrates that one sample is insufficient to reliably assess water quality, particularly in the waterways such as those of the lower Hunter region where macroinvertebrate taxa may be less abundant and not uniformly distributed as a result of degraded water quality. Applying the multiple sample strategies using ten macroinvertebrate samples, no evidence of ongoing impacts on water quality as a result of wastewater treatment plant effluent discharge was detected using SIGNAL2 and AUSRIVAS at Cessnock, Branxton and Farley. However, at Kurri Kurri there was an observable deterioration in water quality between the upstream and downstream sites. The optimal numbers of macroinvertebrate samples required to produce more reliable assessments of water quality and creek health were determined for SIGNAL2 and AUSRIVAS, so that these methods could be usefully incorporated into Hunter Water Corporation’s ongoing water quality monitoring program. It was determined that four samples per site allowed for the detection of a difference in mean SIGNAL2 scores of one SIGNAL2 unit between sites (power = 0.9) for the SIGNAL2 method, and six samples per site were recommended to detect a difference in mean OE50 value of 0.2 OE50 units (power = 0.9) between sites using AUSRIVAS. Therefore, in the creeks of the lower Hunter Valley it is recommended that multiple macroinvertebrate samples are necessary to produce a statistically valid and reliable biotic index, and that the single sample methods of SIGNAL2 and AUSRIVAS are ineffective. These results also demonstrate that it is necessary to derive the optimum sample numbers to obtain statistically significant outcomes using these biotic indices. The importance of these rapid biological assessment techniques is unquestioned, but the implementation of them must produce scientifically robust and defendable outcomes. As an outcome from this investigation it is recommended at the use of SIGNAL2 and AUSRIVAS should include a multi-sampling strategy, not a single sample, particularly for waterways that have been disturbed by industrial, urban or agricultural impacts. Furthermore, where waterways represent different systems, it is necessary to conduct a preliminary study to statistically determine the validity of the number of samples necessary to characterise a site. The definition of different systems is based on a number of landscape and riverine characteristics; for example the streams (rivers) in the current investigation have relatively restricted catchments, but are connected to a larger river system.

Although the importance of fire management for biodiversity conservation is increasingly being recognised, little is known about the relationship between fire regimes and plant diversity in Australia’s temperate grassy woodland ecosystems. This project sought to address this gap in the woodlands of Western Sydney’s Cumberland Plain. Aspects of vegetation dynamics were investigated through six studies, mostly in shale-based Cumberland Plain Woodland (CPW) remnants. Results indicate that fire frequency profoundly affects both vegetation composition and structure. The influence of fire cycles was most readily apparent in the shrub layer. Findings from the six studies were synthesized into a state and transition model which allows exploration of management actions. Interfire intervals between 4 and 12 years are predicted to maintain Themeda woodland with both Bursaria thickets and open areas, and obligate seeder shrubs. Variable intervals across time and space within these thresholds should maintain much of the landscape at fuel levels compatible with property protection; fuel loads in CPW peak well below those in woodlands on sandstone. Low fire frequency remnants dominated by Bursaria retain many conservation values, but are likely to support lower abundances of obligate seeder shrubs and open patch herbs, and to be more weed-prone, than remnants burnt once or twice a decade. Experimentation with one or two short interfire intervals may be appropriate in long unburnt CPW.
Doctor of Philosophy (PhD)

In this thesis, aspects of the reproductive biology of four Banksia species that display in various combinations all the life histories currently recognised in the genus were compared. Species like banksias, from fire prone regions of the world are typically characterised by life histories (traits and organs) that in reference to fire response allow them to be classified as seeders or sprouters. Plants killed by fire and that rely on seed for regeneration are called seeders and those that have the capacity to survive fire and produce vegetative sprouts are called sprouters. The species are Banksia ericifolia, Banksia integrifolia, Banksia oblongifolia, and Banksia serrata. The study was conducted in the Sydney region of Australia, which was arbitrarily divided into North, Central, and Southern provinces for sampling across species. It has been generally hypothesised that several traits are likely to be associated with seeders and sprouters. However, these traits were not always clearly apparent from the author’s studies. It is argued one reason for the anomalies in the expected associated traits is a result of a tendency to assume a evolutionary history that is based on fire as being the primary selection pressure.
Doctor of Philosophy (PhD)