Letteratura scientifica selezionata sul tema "Plant conservation – Western Australia"
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Articoli di riviste sul tema "Plant conservation – Western Australia"
1
Taylor, Gary S., e Melinda L. Moir. "Further evidence of the coextinction threat for jumping plant-lice: three new Acizzia (Psyllidae) and Trioza (Triozidae) from Western Australia". Insect Systematics & Evolution 45, n. 3 (24 luglio 2014): 283–302. http://dx.doi.org/10.1163/1876312x-00002107.
Testo completoAbstract (sommario):
Three new species of jumping plant-lice (Psylloidea) are described from Western Australia. Acizzia hughesae sp.n. occurs on Acacia veronica Maslin (Fabaceae: Mimosoideae), A. mccarthyi sp.n. on an undescribed species of Grevillea (Proteaceae) identified by the Western Australian State Government as in need of conservation action (Grevillea sp. ‘Stirling Range’) and Trioza barrettae sp.n. from the critically endangered Banksia brownii (Proteaceae). These new species of jumping plant-lice are considered rare, and at risk of extinction, or coextinction, as they are recorded from plant species with highly restricted distributions in the south-west of Western Australia. Indeed, the Western Australian State Government recently classified two of the three new jumping plant-lice species as threatened.
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Morris, K. D. "The status and conservation of native rodents in Western Australia". Wildlife Research 27, n. 4 (2000): 405. http://dx.doi.org/10.1071/wr97054.
Testo completoAbstract (sommario):
This paper examines the conservation status of Western Australia’s native rodent fauna using IUCN criteria and compares this with their current status under State and Commonwealth legislation, as well as that recommended in the Rodent Action Plan. Of the 35 native rodent taxa known in Western Australia, four (11%) are currently listed as extinct, and six (17%) as threatened under Western Australian legislation. Nine are listed as threatened under Commonwealth legislation. It is proposed that two, currently unlisted, island sub-species should be regarded as threatened. Some decreases in conservation status are also proposed. Predation by feral cats, habitat destruction and the use of surface shelter structures are suggested as primary factors in the decline of native rodents. Conservation programs are underway for most threatened taxa in Western Australia, including the implementation of recovery plans for the Shark Bay mouse and greater stick-nest rat. The heath rat is the only threatened rodent lacking a conservation program in Western Australia. The work planned or required for rodent conservation is presented and includes survey for the critically endangered central rock-rat, and translocation programs for other threatened taxa. The distribution of most taxa is relatively well known; however, there is a need to commence, or complete, taxonomic assessment of some.
3
Norton, Sally L., Colin K. Khoury, Chrystian C. Sosa, Nora P. Castañeda-Álvarez, Harold A. Achicanoy e Steven Sotelo. "Priorities for enhancing the ex situ conservation and use of Australian crop wild relatives". Australian Journal of Botany 65, n. 8 (2017): 638. http://dx.doi.org/10.1071/bt16236.
Testo completoAbstract (sommario):
Crop wild relatives – the wild cousins of cultivated plants – are increasingly recognised for their potential to contribute to the productivity, nutritional quality and sustainability of agricultural crops. However, the use of these genetic resources is dependent upon their conservation in genebanks and consequent availability to plant breeders, the status of which has not been comprehensively analysed in Australia. Such conservation assessments are given urgency by reports of increasing threats to natural populations due to habitat destruction, climate change, and invasive species, among other causes. Here we document Australian wild plants related to important food crops, and outline their priorities for ex situ conservation. Given that no major domesticated food plants originated in the country, Australia’s native flora of crop wild relatives is surprisingly rich, including potentially valuable cousins of banana, eggplant, melon, mung bean, pigeonpea, rice, sorghum, sweetpotato, soybean and yam. Species richness of the wild relatives of major food crops is concentrated in the northern and north-eastern tropical regions, in the Northern Territory, Western Australia, and Queensland. Geographic priorities for collecting of these taxa for ex situ conservation, due to the limited representation of their populations in genebanks, largely align with areas of high species richness. Proposed dam building and agricultural expansion in northern Australia make conservation action for these species more urgent. We outline key steps needed for enhancing the ex situ conservation of Australia’s heritage of major food crop wild relatives, and discuss the critical activities required to increase their use.
4
Twigg, Laurie. "Fluoroacetate-bearing vegetation: can it reduce the impact of exotic mammals on wildlife conservation?" Pacific Conservation Biology 17, n. 4 (2011): 299. http://dx.doi.org/10.1071/pc110299.
Testo completoAbstract (sommario):
THERE is no doubt that fluoroacetate-bearing vegetation (also known as poison peas) has had a profound effect on the evolution and persistence of Western Australian biota. Most of these plants belong to the genus Gastrolobium, and most are found in the south-west corner of Western Australia (Gardner and Bennetts 1956; Aplin 1971; Twigg and King 1991). The toxic principle of these plants, fluoroacetate, is also manufactured synthetically as 1080 (sodium fluoroacetate) for Australiawide control of vertebrate pests, such as rabbits Oryctolagus cuniculus, foxes Vulpes vulpes, wild dogs Canis lupus familiaris and feral Pigs Sus scrofa (Twigg and King 1991). Because of their co-evolution with fluoroacetate-bearing vegetation, many native animals in Western Australia have developed varying levels of tolerance to this highly toxic compound. In contrast, introduced mammals are generally highly sensitive to fluoroacetate. Although it is not a prerequisite for safe and effective pest control programmes with 1080, the toxicity differential between native and introduced animals provides an additional “safety net” when using 1080 products in Western Australia.
5
Byrne, M. "Phylogeography provides an evolutionary context for the conservation of a diverse and ancient flora". Australian Journal of Botany 55, n. 3 (2007): 316. http://dx.doi.org/10.1071/bt06072.
Testo completoAbstract (sommario):
Phylogeography can inform conservation strategies through assessment of genetic diversity that incorporates an evolutionary perspective, and allows evaluation within a geographical context, thus providing integration with other biogeographical information. Comparative phylogeography can identify significant historical processes that have had major influences on the biota and provides a historical context for understanding current species distributions. The phylogeographic patterns in the flora of south-western Australia are reviewed. Concordant patterns of lineage divergence in three unrelated taxa from separate families with widespread distributions indicate a common response to major historical processes involved in Pleistocene climatic fluctuations. Identification of highly divergent haplotypes in some species indicates areas that may represent refugia during times of climatic instability. Analysis of phylogeographic patterns in the flora of south-western Australia has revealed the influence of historical climate change in promoting high phylogenetic diversity within species that is comparable to the high species diversity that is well known in the Western Australian flora. Knowledge of historical influences and species responses provides an evolutionary context for conservation management strategies that facilitate the continued action of dynamic evolutionary processes.
6
Keighery, Greg J., Neil Gibson, Stephen van Leeuwen, Michael N. Lyons e Sue Patrick. "Biological survey and setting priorities for flora conservation in Western Australia". Australian Journal of Botany 55, n. 3 (2007): 308. http://dx.doi.org/10.1071/bt06102.
Testo completoAbstract (sommario):
Biological survey has been an integral component of conservation planning in Western Australia for >30 years, providing baseline data for reserve selection and the management of biodiversity at the genetic, species and community levels. Flora surveys are particularly important, given the diverse and poorly documented nature of the state’s vascular flora. Surveys have been conducted at the following four scales: regional, subregional, local and individual species. At all scales, flora surveys have provided detail on individual taxon distribution, have identified previously unknown or unrecognised taxa, have located presumed extinct taxa and have substantially contributed to information on the distribution of threatened flora. Regional-scale surveys normally involve multidisciplinary teams studying a broad selection of the biota. These combined plot-based data are used to develop a ‘classify-then-model’ approach to assessment of comprehensiveness, adequacy and representativeness of the regional conservation reserve system. These regional models describe the broad-scale patterning of common taxa but their utility in reflecting patterns in naturally rare or highly restricted taxa is uncertain. Results from recent surveys show poor correlations between floristic patterning and other components of the biota.
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KEIGHERY, G. "Phytogeography, Biology and Conservation of Western Australian Epacridaceae". Annals of Botany 77, n. 4 (aprile 1996): 347–56. http://dx.doi.org/10.1006/anbo.1996.0042.
Testo completo
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E. Davis Jr., William. "Environmental Biology". Pacific Conservation Biology 15, n. 4 (2009): 303. http://dx.doi.org/10.1071/pc090303.
Testo completoAbstract (sommario):
This is an introductory biology textbook that is tailored to the needs of students who will major or take courses in environmental science, conservation, sustainable development, or other areas that deal with anthropogenic problems of habitat degradation, extinction, and human over-population. It is an introductory text in that it presents all the paradigms of biology, including cell theory and evolution, as well as scientific method, field techniques, and problem solving, all with an environmental emphasis. Most of the focus of the numerous examples is on Australian subjects and problems. For example, three case studies presented in the introductory chapter deal with the conflict between timber production and the conservation of Leadbeater?s Possum Gymnobelideus leadbeateri, whether humans caused the outbreak of Crown-of-thorns Starfish Acanthaster planci on Australian reefs, and the conservation of a rare plant species, Corrigin Grevillea Grevillea scapigera, after massive land clearing in Western Australia.
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Hobbs, RJ, e L. Atkins. "Fire-Related Dynamics of a Banksia Woodland in South-Western Western Australia". Australian Journal of Botany 38, n. 1 (1990): 97. http://dx.doi.org/10.1071/bt9900097.
Testo completoAbstract (sommario):
We studied the post-fire vegetation development of a low open woodland dominated by Banksia attenuata and B. menziesii near Perth, Western Australia. Two similar stands burned in autumn and spring displayed different regeneration patterns, with seedling regeneration occurring only in the autumn burn area. Vegetative regrowth was more rapid and post-fire species numbers were higher in the spring burn area. Introduced annuals increased significantly in the autumn fire area. Longer-term vegetation development was studied in a series of stands ranging in age since last fire from 1 to >44 years. Species richness was greatest in the 5-year-old stand, and many shrub species were most abundant 2-5 years after fire. Non-native annuals were found only in stands less than 5 years old since last fire. Dominance by the shrub Eremaea pauciflora increased with stand age, although shrub structure and total biomass did not vary greatly except in the oldest stand studied. The proportion of total shrub biomass accounted for by leaves declined with stand age. Both the two major Banksia species had mixed size structures with seedlings present in all stands, indicating that neither is dependent on fire for recruitment. The results indicate that while autumn burns promote seedling regeneration they may also increase invasion by non-natives, and spring burning may be preferable in these Banksia woodlands. Burning rotations longer than those required for fuel reduction purposes are necessary to maximise conservation values.
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Gibson, N., G. J. Keighery, M. N. Lyons e B. J. Keighery. "Threatened plant communities of Western Australia. 2 The seasonal clay-based wetland communities of the South West". Pacific Conservation Biology 11, n. 4 (2005): 287. http://dx.doi.org/10.1071/pc050287.
Testo completoAbstract (sommario):
The communities of seasonal clay-based wetlands of south-west Australia are described. They are amongst the most threatened In Western Australia. It is estimated that >90% of the original extent of these communities has been cleared for agriculture, and the remaining areas, despite largely occurring in conservation reserves, are threatened by weed invasion and rising saline groundwater. Thirty-six taxa are identified as claypan specialists occurring in six floristic communities. Composition was strongly correlated with rainfall and edaphic factors. The most consistent attribute shared between the seasonal clay-based wetlands of south-west Australia, and the analogous vernal pools systems of California, Chile, and South Africa was the widespread conversion of these wetlands to agricultural systems. The south-west Australia wetlands had a richer flora, different lifeform composition, higher species richness but fewer claypan specialists than the vernal pools of California. The dissimilarity in the regional floras and vegetation types from which the pool floras were recruited explain these differences.
Tesi sul tema "Plant conservation – Western Australia"
1
Swarts, Nigel. "Integrated conservation of the rare and endangered terrestrial orchid Caladenia huegelii H.G. Reichb". University of Western Australia. School of Earth and Geographical Sciences, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0044.
Testo completoAbstract (sommario):
The Orchidaceae is characterized by a remarkably diverse range of life forms and some of the most highly specialized interactions with soil fungi and insect pollinators found in the flowering plants. Many species are rare or threatened with extinction either directly through loss of habitat or over-collection or, indirectly through debilitation or loss of mycorrhizal association or pollinator capacity. Australian temperate terrestrial orchids represent one of the most threatened groups in the Australian flora with many taxa clinging to existence in urban and rural bushland remnants, road verges and unprotected bushland. The aim of this study is to research and develop integrated conservation based on critical aspects of terrestrial orchid biology and ecology, towards the recovery of the rare and endangered Western Australian terrestrial orchid Caladenia huegelii. This study identified key aspects involved in an integrated conservation approach and research focused on conservation genetics, mycorrhizal interactions and in situ and ex situ conservation strategies for this species. Using polymorphic microsatellite molecular markers, high levels of genetic diversity were found within remnant populations of C. huegelii, while weak differentiation was observed among populations over the species geographic range. These results indicate historic genetic exchange between C. huegelii populations, a possible consequence of the sexually deceptive pollination strategy and the capacity for widespread seed dispersal. Symbiotic germination studies revealed compatibility barriers to C. huegelii germination with the orchid possessing a highly specific orchid-mycorrhizal association relative to common sympatric congeners. These results were reflected in a phylogenetic analysis of DNA sequences, revealing C. huegelii associates with only one endophyte species within the fungal family Sebacinaceae across its geographic range. Large scale in situ seed baiting demonstrated that endophytes compatible with C. huegelii were limited in distribution relative to common and widespread orchid species, a feature for C. huegelii that may be a major contributing factor in limiting the distributional range of the species. Detailed, within site seed baiting methods identified hotspots for mycorrhizal fungus compatible with C. huegelii that were unoccupied by the orchid. These mycorrhizal hotspots where used to investigate the effect of endophyte presence on survival of transplanted mature plants and seedling outplants. The in situ survival of glasshouse propagated seedlings was further optimized by incubating seedlings in growth containers before transfer to soil and outplanting seedlings in their second growing season. The findings of this study will substantially advance the recovery of C. huegelii and provide benchmark knowledge for similar projects with other rare and threatened terrestrial orchid species.
2
Horsnell, Tara Kathleen. "Quantifying thresholds for native vegetation to salinity and waterlogging for the design of direct conservation approaches". University of Western Australia. School of Environmental Systems Engineering, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0082.
Testo completoAbstract (sommario):
A field-based project was undertaken to develop and test a mechanism which would allow for the correlation of the health of vegetation surrounding playa lakes in south-west Australia with the natural variation in salinity and waterlogging that occurs spatially and temporally in natural systems. The study was designed to determine threshold ranges of vegetation communities using moderately extensive data over short temporal periods which will guide the design of potential engineering solutions that manipulate hydrological regimes to ultimately conserve and protect native vegetation. A pair of playa lake ecosystems, surrounded by primary production land, was modelled with hydro-geological data collected from March 2006 to March 2007. The data was used to determine the hydroperiods of vegetation communities fringing playa lakes and provide insight into the areas and species that are most affected by extreme rainfall events which are hypothesised to have a significant, rapid deleterious effect on the ecosystems. The methodology was multi-faceted and included; a detailed topographical survey; vegetation surveys; hydrological and hydro-geological monitoring over a 12 month period. 4 The hydro-geological data and vegetation data was linked with the topographical survey at a high resolution for spatial analysis in a Geographic Information System (GIS) to determine the degree of waterlogging experienced by vegetation communities over the monitoring period. The study has found that the spatial and temporal variability of hydroperiods has been reduced by rising groundwater levels, a result of extensive clearing of native vegetation. Consequently populations are becoming extinct locally resulting in a shift in community composition. Extreme summer rainfall events also have a significant impact on the health of vegetation communities by increasing the duration of waterlogging over an annual cycle and in some areas expanding the littoral zone. Vegetation is most degraded at lower positions in the landscape where communities are becoming less diverse and dominated by salt tolerant halophytic species as a result of altered hydrological regimes. Some species appear to be able to tolerate groundwater depths of less than 2.0 m from the surface, however there are thresholds related to the duration at which groundwater is maintained at this depth. Potential engineering solutions include groundwater pumping and diverting water through drains to maintain sustainable hydroperiods for vegetation in areas with conservation value. The effectiveness and efficiency of the engineering solutions can be maximised by quantifying thresholds for vegetation that include sustainable durations of waterlogging. The study has quantified tolerance ranges to salinity and waterlogging with data collected over 12 months but species may be experiencing a transition period where they have 5 sustained irreversible damage that will result in their eventual mortality. With long-term monitoring, the methodology developed and tested in the study can be used to quantify the long-term tolerance ranges that are important for the application of conservation approaches that include engineering solutions.
3
Hollick, Penelope Sarah. "Mycorrhizal specificity in endemic Western Australian terrestrial orchids (tribe Diurideae) : implications for conservation /". Hollick, Penelope Sarah (2004) Mycorrhizal specificity in endemic Western Australian terrestrial orchids (tribe Diurideae): implications for conservation. PhD thesis, Murdoch University, 2004. http://researchrepository.murdoch.edu.au/103/.
Testo completoAbstract (sommario):
The specificity of fungal isolates from endemic Western Australian orchid species and hybrids in the tribe Diurideae was investigated using symbiotic seed germination and analysis of the fungal DNA by amplified fragment length polymorphism (AFLP). The distribution of the fungal isolates in the field was also assessed using two different seed baiting techniques. The information from these investigations is essential for developing protocols for reintroduction and translocation of orchid species.
Two groups of orchids in the tribe Diurideae were studied. Firstly, a number of Caladenia species, their natural hybrids and close relatives from the southwest of Western Australia were selected because orchid species from the genus Caladenia are considered to have among the most specific mycorrhizal relationships known in the orchid family ? an ideal situation for the investigation of mycorrhizal specificity. Secondly, species of Drakaea and close relatives, from the southwest of Western Australia and elsewhere in Australia, which are never common in nature and occur in highly specialised habitats, were selected to investigate the influence of habitat on specificity.
Seed from the common species Caladenia arenicola germinated on fungal isolates from adult plants of both C. arenicola and its rare and endangered relative C. huegelii, while seed from C. huegelii only germinated on its own fungal isolates. The AFLP analysis grouped the fungal isolates into three categories: nonefficaceous fungi, C. huegelii type fungi, and C. arenicola type fungi. The group of C. huegelii type fungi included some fungal isolates from C. arenicola. An analysis of the AFLP fingerprints of C. arenicola fungal isolates from different collection locations showed that some, but not all, populations were genetically distinct, and that one population in particular was very variable.
Despite being thought to have very specific mycorrhizal relationships, Caladenia species hybridise frequently and prolifically in nature, often forming self-perpetuating hybrid lineages. Five natural hybrids within Caladenia and its closest relatives were investigated. Symbiotic cross-germination studies of parental and hybrid seed on fungi from the species and the naturally occurring hybrids were compared with AFLP analyses of the fungal isolates to answer the question of which fungi the hybrids use. The germination study found that, while hybrid seeds can utilise the fungi from either parental species under laboratory conditions, it is likely that the natural hybrids in situ utilise the fungus of only one parental species. Supporting these observations, the AFLP analyses indicated that while the parental species always possessed genetically distinct fungal strains, the hybrids may share the mycorrhizal fungus of one parental species or possess a genetically distinct fungal strain which is more closely related to the fungus of one parental species than the other.
The work on Caladenia hybrids revealed that C. falcata has a broadly compatible fungus that germinated seeds of C. falcata, the hybrid C. falcata x longicauda, and species with different degrees of taxonomic affinity to C. falcata. In general, germination was greater from species that were more closely related to C. falcata: seeds from Caladenia species generally germinated well on most C. falcata isolates; species from same subtribe (Caladeniinae) germinated well to the stage of trichome development on only some of the fungal isolates and rarely developed further; and seeds from species from different subtribes (Diuridinae, Prasophyllinae, Thelymitrinae) or tribes (Orchideae, Cranichideae) either germinated well to the stage of trichome development but did not develop further, or did not germinate at all. The AFLP analysis of the fungal isolates revealed that the fungi from each location were genetically distinct.
In situ seed baiting was used to study the introduction, growth and persistence of orchid mycorrhizal fungi. A mycorrhizal fungus from Caladenia arenicola was introduced to sites within an area from which the orchid and fungus were absent, adjacent to a natural population of C. arenicola. In the first growing season, the fungus grew up to 50 cm from its introduction point, usually persisted over the summer drought into the second season and even into the third season, stimulating germination and growth to tuber formation of the seeds in the baits. Watering the inoculated areas significantly increased seed germination.
Mycorrhizal relationships in Drakaeinae were less specific than in Caladeniinae. A study of the species Spiculaea ciliata revealed that this species, when germinated symbiotically, develops very rapidly and has photosynthetic protocorms, unlike all other members of the Drakaeinae. An AFLP analysis of the fungal isolates of this species grouped the isolates according to whether they had been isolated from adult plants or reisolated from protocorms produced in vitro. Isolates were genetically distinct when compared before germination and after reisolation. A cross-species symbiotic germination study of seeds of three Drakaea species and one Paracaleana species against fungal isolates from the same species and several other Drakaeinae species revealed lower specificity in this group than previously thought. A number of fungal isolates from Drakaea and Paracaleana species germinated two or more seed types, while all seed types germinated on fungal isolates from other species and the seed of Drakaea thynniphila germinated to some extent on every fungal isolate tested. An AFLP analysis of the Drakaeinae fungal isolates supported this information, revealing little genetic differentiation between the fungi of different orchid species.
An ex situ seed baiting technique was used to examine the role of mycorrhizal fungi in microniche specialisation in the narrow endemic Drakaea. Soil samples from within and outside two Drakaea populations were tested for germination of the relevant seed types. In both cases, germination was significantly higher on soil samples from within than outside the populations, suggesting that the relevant mycorrhizal fungi may be restricted to the same microniches as the Drakaea species. The presence of similar fungi at distant, disjunct locations may be related to the extreme age and geological stability of the Western Australian landscape.
The information from these investigations is essential for developing protocols for reintroduction and translocation of orchid species. It appears that the mycorrhizal relationships in these groups of orchids are not as specific as was previously thought. For reintroduction work, a broad sampling strategy is necessary, as it cannot be assumed that the same orchid species has the same fungus at different locations. A broadly compatible fungus may be of considerable utility in conservation work, such as in situations where a specific fungus appears to have poor saprophytic competence or where soil conditions have been altered. Seed baiting studies provide additional data on fungal distribution in situ. In general, molecular data do not provide information about efficacy or fungal distribution, so research programs that combine symbiotic germination studies with seed baiting investigations and genetic analyses of the fungi will provide the maximum benefit for designing more effective conservation programs.
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Bougoure, Jeremy J. "The role of mycorrhizal fungi in nutrient supply and habitat specificity of the rare mycoheterotrophic underground orchid, Rhizanthella gardneri". University of Western Australia. School of Plant Biology, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0076.
Testo completoAbstract (sommario):
Rhizanthella gardneri (Rogers) is a critically endangered orchid restricted to two isolated regions of south-western Australia. Rhizanthella gardneri is an entirely subterranean mycoheterotrophic species that purportedly forms a tripartite relationship with a mycorrhizal fungus (Ceratobasidiales) that links with an autotrophic shrub of the Melaleuca uncinata complex to acquire nutrients. Whether the rarity of R. gardneri is intrinsic is overshadowed by the recent effect of extrinsic factors that means R. gardneri requires some form of conservation and may also be a viable candidate for restoration. To create an integrated conservation strategy for R. gardneri, reasons for its decline and knowledge of its biological and ecological functioning must be elucidated. This thesis focuses on three key questions; 1) what are the habitat requirements and limitations to R. gardneri survival; 2) what is the identity and specificity of the fungus R. gardneri forms mycorrhizas with; and 3) does R. gardneri form a nutrient-sharing tripartite relationship with a mycorrhizal fungus and autotrophic shrub. Key climate, soil and vegetation characteristics of known R. gardneri habitats were quantified to provide baseline data for monitoring known R. gardneri populations, to better understand how R. gardneri interacts with its habitat, and to identify possible new sites for R. gardneri introduction. Habitats of the two known R. gardneri populations differed considerably in soil chemistry, Melaleuca structure and Melaleuca productivity. Individual sites within populations were relatively similar in all attributes measured while overall Northern and Southern habitats were distinct from each other. These results suggest that R. gardneri can tolerate a range of conditions and may be more widespread than previously thought, given that there are extensive areas of Melaleuca thickets with similar habitat characteristics across south-western Australia. The fungus forming mycorrhizas with R. gardneri was identified, using nuclear ribosomal DNA sequences, as a Rhizoctonia-type fungus within the Ceratobasidiales. All fungi isolated from R. gardneri individuals representative of its currently known distribution were genetically similar, suggesting R. gardneri is highly dependent on this specific fungal species. Given that R. gardneri appears to exclusively associate with a specific fungal species, species-specific molecular primers were designed and used to analyse the fungis presence in known and potential R. gardneri habitats. These results 6 suggest that the fungus exists beyond the known R. gardneri habitats and gives hope to finding new populations.
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Sutcliffe, Karen Elizabeth. "The conservation status of aquatic insects in south-western Australia". Murdoch University, 2003. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040430.153605.
Testo completoAbstract (sommario):
Freshwater ecosystems in south-western Australia have been extensively altered over the last two centuries as a result of human activities. The effect this has had on aquatic fauna, particularly invertebrates, is largely unknown because of inadequate knowledge of the pre-existing fauna. Future changes in the composition of aquatic fauna will also go undetected unless current distributions of existing species are well documented.
This thesis addresses the problem by investigating the current distributions and conservation status of aquatic insects in south-western Australia from three orders: Odonata, Plecoptera and Trichoptera. Extensive distributional data was collected by identifying larval specimens from a large number of samples collected throughout the south-west as part of an Australia-wide macroinvertebrate bioassessment project. In addition, a database created from a species-level biological study of the wheatbelt region of Western Australia was utilised, and previously published records of occurrence for species within the south-west were compiled. These results were then used to assess the conservation status of each species using the IUCN red list criteria.
Environmental parameters measured at time of sampling were also examined using logistic regression to determine which factors are important in influencing the distributions of aquatic insects in south-western Australia. The conservation value of sites based on Odonata, Plecoptera and Trichoptera compositions was also determined and the degree of protection provided for sites of high conservation value investigated.The high rainfall forested region of the south-west was found to be important for a large number of species, including the majority of those found to be rare and/or restricted.
Overall, 37% of species were found to be threatened, with the Trichoptera containing both the greatest number and highest proportion of threatened species. Logistic regression results generally agreed with the distributions obtained for each species, with rainfall and other parameters indicative of streams in the headwaters of forested catchments being positively associated with species found to be restricted to the high rainfall region. Two parameters known to be affected by human disturbance in the south-west, conductivity and nutrient concentrations, were found to be important in determining the occurrence of many species and this could have important consequences for aquatic insect conservation. Widespread species occurring within the low rainfall region of the south-west did not show as many significant relationships to measured environmental parameters, possibly due to their greater ecological tolerances and adaptations which allow them to persist in a low rainfall environment. The implications of results are discussed, and recommendations for the conservation and management of aquatic insects in south-western Australia are given.
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Sutcliffe, Karen. "The conservation status of aquatic insects in South-Western Australia /". Access via Murdoch University Digital Theses Project, 2003. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040430.153605.
Testo completo
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Naude, Minette. "Fynbos riparian biogeochemistry and invasive Australian acacias". Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20325.
Testo completoAbstract (sommario):
Thesis (MScConEcol)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Riparian ecotones, transitional areas between upland terrestrial communities and aquatic ecosystems, are very dynamic and complex ecosystems with intrinsic ecological properties differing in spatial structure, function and temporal dynamics. Riparian habitats along rivers of the Mediterranean south-western Cape are sensitive to environmental change and particularly vulnerable to invasion by invasive alien plants (IAPs), especially nitrogen-fixing Acacia spp., and yet relatively little work has focused on how riparian ecosystems in this region respond to such stressors. The important roles that intact riparian vegetation play in maintaining ecosystem integrity and services have been increasingly highlighted as we acknowledge the degradation of these habitats. While the Working for Water (WfW) programme has been shown to be very successful in eradicating IAPs in riparian zones in the short-term, the extent to which riparian ecosystems recover following alien clearing activities remains poorly understood. The results presented in this study addressed several different aspects of riparian structure and function and acts as a steppingstone for guiding future research and management in riparian zones by adding to the evaluation of the success of clearing initiatives and restoration thereof. The aim of this study was to assess plant functional type (PFT) cover, soil physical and chemical properties, and selected biogeochemical processes in natural, Acacia- invaded and cleared riparian ecotones and associated non-riparian upland fynbos. Fieldwork was performed in mountain and foothill sections of six perennial river systems within the south-western Cape. Eleven sites of three categories were chosen: four natural sites (uninvaded); four moderate to highly invaded sites (predominantly A. mearnsii); and three cleared sites (a formerly invaded site that had been cleared more than 7 years prior to the study). Within each site, four to five replicate plots were established along each of three geomorphological zones (wet bank, dry bank, and upland fynbos). Seasonal soil samples were collected for a period of one year. Results from this study showed that PFT cover and composition, soil physical and chemical properties and rates of nitrogen (N) and phosphorus (P) mineralization differed amongst invasion status, between geomorphological zones and across seasons. Regarding most soil physical and chemical properties and indices N and P cycling, river floodplains (dry banks) were very similar to terrestrial uplands. Acacia spp. changes soil properties and affects plant functional attributes by i) enriching the system with N; ii) enhancing litter inputs; iii) altering soil physical properties; iv) changing the composition and reducing the cover of PFT; and v) enhancing P mineralization rates. Although measured soil physical and chemical properties and N and P mineralization rates were reduced to levels that were similar to or resembled the situation at natural areas, available inorganic N remained two times higher after more than seven years of clearance. Furthermore, cleared areas were characterized by sparse woody cover and a high cover of alien grasses. Correlations between soil silt and clay content and several soil properties measured in this and other studies indicates important linkages between soil texture and resource availability. Clearing Acacia spp. may initiate restoration of invaded riparian ecosystems, but changes in ecosystem function (e.g. elevated soil N availability) as a result of invasion may necessitate active restoration following the removal of the alien species. Active restoration under such conditions would be required to facilitate the restoration of cleared riparian communities. However, we still lack the mechanistic understanding around fynbos riparian recovery after clearing, as the success of restoration may depend on complex interaction and feedback cycles between plants and their physical environment. A greater comprehensive understanding of fynbos riparian ecological processes will not only improve the effectiveness of restoration initiatives by integrating science and management, but also advance the field of riparian ecology.
AFRIKAANSE OPSOMMING: Rivier oewerwal-areas, oorgang gebiede tussen aangrensende terrestriële gemeenskappe en akwatiese ekosisteme, is baie dinamiese en komplekse ekosisteme met intrinsieke ekologiese eienskappe wat verskil in struktuur, funksie (bv. biogeochemie siklusse) en temporale dinamika. Oewerhabitatte langs riviere van die Mediterreense suid-wes Kaap is sensitief vir omgewingsveranderinge en kwesbaar vir indringing deur uitheemse plante (bekend as “invasive alien plants” (IAPs)), veral stikstof-fiksering Acacia spp., en relatief min werk het nog gefokus op hoe ekosisteme in die streek reageer op sulke veranderinge in die omgewing. Die belangrike rol wat gesonde oewerwal plantegroei speel in die handhawing van ekosisteemdienste- en integriteit, is al hoe meer uitgelig soos ons die agteruitgang van hierdie habitat in ag neem. Terwyl die Werk vir Water (WvW)-program al dat baie suksesvol was in die uitwissing van IAPs in oewersones in die kort termyn, is die mate waarin oewer-ekostelsels herstel na skoonmaakaksies swak verstaan. Fynbos oewerwal-areas is grootliks ingeneem deur houtagtige IAPs, veral stikstof fiksering Acacia spp. (soos Acacia mearnsii). Die resultate wat in hierdie studie aangebied is, het verskillende aspekte van oewer- struktuur en funksie aangespreek en dien as middel vir toekomstige navorsing en bestuur van oewerwal ekosisteme deur by te dra tot die evaluering van die sukses van skoonmaak inisiatiewe en die herstelproses daarvan. Die doel van hierdie projek was om die moontlikhede vir herstel van fynbos owerwal-ekostelsels te evalueer deur middel van verskeie grond- fisiese en chemiese eienskappe; plant funksionele groep dekking (genoem ‘plant functional types’ (PFT)); en geselekteerde grond biogeochemie prosesse in natuurlike, Acacia- aangetaste, en skoongemaakte rivierstelsels en nabygeleë terrestriese areas te vergelyk. Veldwerk is gedoen in bergstroom en voetheuwel rivierseksies van ses standhoudende rivierstelsels in Suid-wes Kaap, Suid Afrika. Van uit hierdie geselekteerde rivierstelsels is elf studie areas van drie kategorieë (of indringing status) gekies: vier natuurlike areas (nie aangetas); vier gematig- tot hoogs aangetaste areas (hoofsaaklik A. meanrsii); en drie skoongemaakte areas (rivieroewers wat meer as sewe jaar van te vore skoongemaak is). Binne elke studie area was vier tot vyf soortgelyke persele gevestig by elke van drie breë geomorfologiese sones: naamlik nat-, droë en hoogliggende terrestriese fynbos. Seisoenale grondmonsters vir 'n tydperk van een jaar is geneem. Resultate van hierdie studie het getoon dat PFT dekking en samestelling, grond fisiese- en chemiese eienskappe en N-mineralisasie en suur fosfatase aktiwiteit verskil tussen indringing status, geomorfologiese sones en oor seisoene. Ten opsigte van meeste grond fisiese en chemiese eienskappe en indekse van stikstof (N) en fosfor (P) siklusse kom die rivier vogregimes (droë oewersones) baie ooreen met die terrestriële gebiede. Aan die anderkant is die natbanksones gekenmerk deur grondeienskappe wat baie verskil van die ander twee geomorfologiese gebiede. Die gegewens ondersteun die hipotese dat indringing deur Acacia spp. verskeie grondeienskappe verander en plante se funksionele kenmerke beïnvloed deur i) die sisteem met voedingstowwe te verryk (veral N); ii) verhoog die toevoeging van plantmateriaal; iii) verander grond fisiese eienskappe; iv) verander die samestelling en verminder die dekking van PFT; v) en verhoog P biogeochemie. Hoewel grond fisiese -en chemiese eienskappe, en indekse van N en P mineralisasie verminder is tot vlakke wat soortgelyk aan natuurlike areas, het beskikbare anorganiese N twee keer hoër gebly by skoongemaakte gebiede. Nietemin, voorheen skoongemaakte gebiede is weer-binnegeval deur eksotiese grasse en die regenerasie of hertelling van inheemse fynbos gemeenskappe is taamlik beperk, veral houtagtige oewer struike en bome. Korrelasies tussen grond slik-en klei-inhoud en verskeie grondeienskappe gemeet in hierdie en ander studies dui op belangrike skakeling tussen die grondtekstuur en voedingstof beskikbaarheid. Die opruiming van Acacia spp. mag as aansporing dien vir die herstellingsproses van rivieroewerstelsels, maar veranderinge in die funksie van ekosisteme (bv. verhoogte grond N beskikbaarheid), as gevolg van indringing, mag aktiewe herstel noodsaak nadat die indringer spesies verwyder is. Aktiewe herstel onder sulke omstandighede sal verwag word om die herstel van skoongemaak oewer gemeenskappe te fasiliteer. Ons het wel egter nog 'n gebrek aan die meganistiese begrip in verband met die herstel van fynbos oewerwal areas na opruimings-inisiatiewe, sedert die sukses van herstel kan afhang van komplekse interaksie en terugvoer siklusse tussen die plante en hul fisiese omgewing. ʼn Meer omvattende begrip van fynbos rivieroewer ekologiese prosesse sal nie net die doeltreffendheid van opruimings-inisiatiewe deur die integrasie van wetenskaplike navorsing en bestuur verbeter nie, maar ook vooraf die gebied van rivieroewer-ekologie.
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Mursidawati, Sofi. "Mycorrhizal association, propagation and conservation of the myco-heterotrophic orchid Rhizanthella gardneri". University of Western Australia. School of Earth and Geographical Sciences, 2004. http://theses.library.uwa.edu.au/adt-WU2004.0014.
Testo completoAbstract (sommario):
Many orchids require mycorrhizal symbioses with fungi for their development and survival. Rhizanthella gardneri the Western Australian underground orchid is associated with the companion plant Melaleuca uncinata and its ectomycorrhizal fungus symbiont. Much less is known about the habitat requirements of its sister species, R. slateri, which occurs in Eastern Australia. The absence of chlorophyll from Rhizanthella gardneri and R. slateri results in total dependency on associations with fungal symbionts. Many ecological and biological aspects of these fascinating orchids remained poorly known, including the identity of the fungal associates and the nature of their tripartite associations with Rhizanthella and Melaleuca. Extremely high specificity of these mycorrhizal relationships is likely to be the most important factor explaining the highly specific habitat requirements of underground orchids. The purpose of this study was to conduct further investigations of the role of the mycorrhizal associations of Australian underground orchids by identifying the fungi involved in these associations, optimising their growth in sterile culture and devising efficient means for synthesising their tripartite associations with R. gardneri and M. uncinata. In total, 16 isolates of fungi were successfully obtained from the two underground orchids and used in a series of experiments to understand both the nature of the fungi and their relationship with orchids. The identity of these fungi was established by using conventional morphological and molecular methods. Cultural and morphological studies revealed that all isolates from R. gardneri and R. slateri were binucleate rhizoctonias with affinities to members of the genus Ceratobasidium. However, the teleomorph state that was observed from the R. slateri symbiont during this study more closely resembled a Thanatephorus species. Further identification using ITS sequence comparisons confirmed that mycorrhizal fungi of Rhizanthella belonged to the Rhizoctonia alliance with relatives that include Thanatephorus, Ceratobasidium, or Rhizoctonia from other continents with over 90% similarity. Most of these related fungi are known as plant pathogens, but some were orchid mycorrhizal fungi. However, the isolates from the two underground orchids were most closely related to each other and formed a discrete group relative to other known members of the Rhizoctonia alliance. Sterile culture experiments determined culture media preferences for mycorrhizal fungi from Rhizanthella and other orchids. A fully defined sterile culture medium designed to more closely resemble Australian soil conditions was formulated. This new medium was compared to undefined media containing oats or yeast extract and recommendations for growth of these fungi are provided. The undefined media based on oats provided the best growth of most fungi, but the new Australian soil media was also effective at growing most orchid mycorrhizal fungi and this fully defined media was less prone to contamination and should provide more reproducible results. A comparison of three methods for inoculating M. uncinata with the underground orchid fungi resulted in the production and characterisation of ectomycorrhizal roots and hyphae formed by fungi isolated from R. gardneri and R. slateri. These underground orchid fungi could easily be distinguished from other mycorrhizal fungi (caused by airborne contamination) by the characteristic appearance of these roots and hyphae. A new system for growing and observing tripartite mycorrhizal associations was devised using pots with side viewing windows and the use of transparent seed packets to contain Rhizanthella seeds. This method allowed all the stages of seed germination to be observed in the glasshouse, culminating in the production of underground orchid rhizomes. Seed germination was only successful when seed was placed directly over active M. uncinata ectomycorrhizas confirmed to belong to the correct fungus by microscopic observations through the side of window pots. The importance of these new scientific discoveries concerning the biology and ecology of the underground orchids and their associated fungi for the recovery of these critically endangered orchids are discussed.
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Pritchard, Deborah Leeanne. "Phosphorus bioavailability from land-applied biosolids in south-western Australia". Curtin University of Technology, Muresk Institute, 2005. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=16492.
Testo completoAbstract (sommario):
The annual production of biosolids in the Perth region during the period of this study was approximately 13,800 t dry solids (DS), being supplied by three major wastewater treatment plants. Of this, 70% was typically used as a low-grade fertiliser in agriculture, representing an annual land use area of around 1,600 ha when spread between 5 and 7 t DS/ha. Loading rates of biosolids are typically based on the nitrogen (N) requirements of the crop to be grown, referred to as the N Limiting Biosolids Application Rate (NLBAR). A consequence of using the NLBAR to calculate loading rates is that phosphorus (P) is typically in excess of plant requirement. The resultant high loading rates of P are considered in the guidelines developed for the agricultural use of biosolids in Western Australia, but lack research data specific to local conditions and soil types. Regulatory changes throughout Australia and globally to protect the environment from wastewater pollution have created a need for more accountable and balanced nutrient data. Experiments presented in this thesis were undertaken to ascertain: the percentage relative effectiveness (RE) of biosolids as a source of plant available P compared with inorganic P fertiliser; loading rates to best supply P for optimum crop growth; P loading rates of risk to the environment; and the forms of P in local biosolids. Therefore, both the agronomic and environmental viewpoints were considered. Anaerobically digested and dewatered biosolids produced from Beenyup Wastewater Treatment Plant, Perth with a mean total P content of 2.97% dry weight basis (db) were used in a series of glasshouse, field and laboratory experiments. The biosolids were sequentially fractionated to identify the forms of P present and likewise in soil samples after applying biosolids or monocalcium phosphate (MCP).The biosolid P was predominantly inorganic (92%), and hence the organic fraction (8%) available for mineralisation at all times would be extremely low. The most common forms of biosolid P were water-soluble P and exchangeable inorganic P (66%), followed by bicarbonate extractable P (19%) and the remaining P as inorganic forms associated with Fe, Al and Ca (14%). Following the application of biosolids to a lateritic soil, the Fe and Al soil fractions sorbed large amounts of P, not unlike the distribution of P following the addition of MCP. Further investigation would be required to trace the cycling of biosolid P in the various soil pools. The growth response of wheat (Triticum aestivum L.) to increasing rates of biosolids and comparable rates of inorganic P as MCP, to a maximum of 150 mg P/kg soil was examined in the glasshouse. The percentage relative effectiveness (RE) of biosolids was calculated using fitted curve coefficients from the Mitscherlich equation: y = a (1-b exp–cx) for dry matter (DM) production and P uptake. The initial effectiveness of biosolid P was comparable to that of MCP with the percentage RE of biosolids averaging 106% for DM production of wheat shoots and 118% for shoot P uptake at 33 days after sowing (DAS) over three consecutive crops. The percentage residual value (RV) declined at similar rates for DM production in MCP and biosolids, decreasing to about 33% relative to freshly applied MCP in the second crop and to approximately 16% in the third crop. The effectiveness of biosolid P was reduced significantly compared with inorganic P when applied to a field site 80 km east of Perth (520 mm annual rainfall). An infertile lateritic podsolic soil, consistent with the glasshouse experiment and representative of a soil type typically used for the agricultural application of biosolids in Western Australia was used.
Increasing rates of biosolids and comparable rates of triple superphosphate (TSP), to a maximum of 145 kg P/ha were applied to determine a P response curve. The percentage RE was calculated for seasonal DM production, final grain yield and P uptake in wheat followed by lupin (Lupinus angustifolius L.) rotation for the 2001 and 2002 growing seasons, respectively. In the first year of wheat, the RE for P uptake in biosolids compared with top-dressed TSP ranged from 33% to 55% over the season and by grain harvest was 67%. In the second year, and following incorporation with the disc plough at seeding, the RE for P uptake by lupins in biosolids averaged 79% over the growing season compared with top-dressed TSP, and by grain harvest the RE was 60%. The residual value (RV) of lupins at harvest in biosolids compared with freshly applied TSP was 47%. The non-uniform placement of biosolids (i.e. spatial heterogeneity) was primarily responsible for the decreased ability of plant roots to absorb P. The P was more effective where biosolids were finely dispersed throughout the soil, less so when roughly cultivated and least effective when placed on the soil surface without incorporation. The RE for grain harvest of wheat in the field decreased from 67% to 39% where biosolids were not incorporated (i.e. surface-applied). The RE could also be modified by factors such as soil moisture and N availability in the field, although it was possible to keep these variables constant in the glasshouse. Consequently, absolute values determined for the RE need to be treated judiciously. Calculations showed that typical loading rates of biosolids required to satisfy agronomic P requirements of wheat in Western Australia in the first season could vary from 0 to 8.1 t DS/ha, depending on soil factors such as the P Retention Index (PRI) and bicarbonate available P value.
Loading rates of biosolids were inadequate for optimum P uptake by wheat at 5 t DS/ha (i.e. 145 kg P/ha) based on the NLBAR on high P sorbing soils with a low fertiliser history (i.e. PRI >15, Colwell bicarbonate extractable P <15 mg P/kg). On soils of PRI <2 mL/g however, biosolids applied at identical loading rates would result in high concentrations of available P. Further work on sites not P deficient would be necessary to validate these findings on farmed soils with a regular history of P fertiliser. The sieving of soil samples used in the field experiment to remove stones and coarse organic matter prior to chemical analysis inadvertently discarded biosolids particles >2 mm, and thus their was little relationship between soil bicarbonate extractable P and P uptake by plants in the field. The risk of P leaching in biosolids-amended soil was examined over a number of different soil types at comparable rates of P at 140 mg P/kg (as either biosolids or MCP) in a laboratory experiment. Given that biosolids are restricted on sites prone to water erosion, the study focussed on the movement of water-soluble P by leaching rather than by runoff of water-soluble P and particulate P. In general the percentage soluble reactive P recovered was lower in soils treated with biosolids than with MCP, as measured in leachate collected using a reverse soil leachate unit. This was particularly evident in acid washed sand with SRP measuring 14% for biosolids and 71% for MCP, respectively, although the differences were not as large in typical agricultural soils. Specific soil properties, such as the PRI, pH, organic carbon and reactive Fe content were negatively correlated to soluble reactive P in leachate and thus reduced the risk of P leaching in biosolids-amended soil.
Conversely, the total P and bicarbonate extractable P status of the soils investigated were unreliable indicators as to the amount of P leached. On the basis of the experiments conducted, soils in Western Australia were categorised according to their ability to minimise P enrichment and provide P necessary for crop growth at loading rates determined by the NLBAR. Biosolids applied at the NLBAR to soils of PRI >2mL/g with reactive Fe >200 mg/kg were unlikely to necessitate P loading restrictions. Although specific to anaerobically digested biosolids cake applied to Western Australian soils, the results will be of relevance to any industry involved in the land application of biosolids, to prevent P contamination in water bodies and to make better use of P in crop production.
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Fisher, Judith L. "Fundamental changes to ecosystem properties and processes linked to plant invasion and fire frequency in a biodiverse woodland". University of Western Australia. School of Plant Biology, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0109.
Testo completoAbstract (sommario):
[Truncated abstract] Mediterranean southwest Australia, a global biodiversity hotspot, has nutrient deficient soils, exacting climatic conditions and is species rich with 7380 native vascular plant species, of which 49% are endemic. The region is expected to experience one of the world's highest degrees of biodiversity loss and change in the coming decades, with introduced species presenting a major threat. Limited knowledge is available on the mechanisms of ecosystem change associated with invasion and fire in this biodiversity hotspot region. Banksia woodland, an iconic complex species-rich natural ecosystem is one of the major vegetation types of the coastal sandplain, extending from 15 to 90 km inland and 400 kms along the west coast. The following hypothesis was tested to explore the ecological impacts of invasion: Is invasion of Banksia woodland by the introduced species Ehrharta calycina and Pelargonium capitatum accompanied by an alteration in ecosystem properties and processes, whereby the degree of change is related to fire frequency and abundance of introduced species? Different vegetation conditions, i.e. Good Condition (GC), Medium Condition (MC), Poor Condition invaded by Ehrharta calycina (PCe) and Poor Condition invaded by Pelargonium capitatum (PCp) were utilized for field assessments. ... In the soil seed bank, species numbers and germinant density decreased significantly for native and seeder (fire sensitive) species between GC sites and invaded sites. Surprisingly 52% of germinants at GC sites were from introduced species, with much of the introduced soil seed bank being persistent. Native species were dominated by perennial shrubs, herbs and sedges, while introduced species were dominated by perennial and annual grasses and herbs. Invasion by introduced species, associated with frequency of fire, altered the ecosystem, thus disadvantaging native species and improving conditions for even greater invasion within the Banksia woodland. Significantly higher soil phosphorus P (total) and P (HCO3) were found at PCe and PCp sites compared to GC sites. Leaf nutrient concentrations of phosphorus were significantly higher, and potassium and copper significantly lower in PCe and PCp sites, with introduced species having significantly greater concentrations than native species (except Manganese). This study demonstrated the key role of phosphorus in the Banksia woodland, in contrast to other research which identified nitrogen as the major nutrient affected by invasion. Higher levels of soil and leaf phosphorus, loss of species diversity and function, changes in fire ecology and canopy cover and a limited native soil seed bank make restoration of a structural and functional Banksia woodland from the soil seed bank alone unlikely. Without management intervention, continuing future fire is likely to result in a transition of vegetation states from GC to MC and MC to PC. The knowledge gained from this study provides a better ecological understanding of the invasive process. This enhanced understanding will enable the development of adaptive management strategies to improve conservation practices within a biodiversity hotspot and reduce the impact of the key threatening process of invasion.
Libri sul tema "Plant conservation – Western Australia"
1
Strawbridge, M. The extent, condition and management of remnant vegetation in water resource recovery catchments in south Western Australia: Report to the Natural Heritage Trust. East Perth, W.A: Water and Rivers Commission, 1999.
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Plant life of Western Australia. Kenthurst, NSW: Kangaroo Press, 1990.
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Burbidge, Andrew A. Threatened animals of Western Australia. Kensington, W.A: Dept. of Conservation and Land Management, 2004.
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Burbidge, Andrew A. Nature conservation reserves in the Kimberley, Western Australia. Como, W.A: Dept. of Conservation and Land Management, 1991.
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Ornduff, Robert. Islands on islands: Plant life on the granite outcrops of Western Australia. Honolulu: Published for Harold L. Lyon Arboretum by the University of Hawaii Press, 1987.
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Rao, T. A. Conservation of wild orchids of Kodagu in the Western Ghats. [Bangalore: Centre for Technology Development], 1998.
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Christensen, P. E. S. The Karri forest: Its conservation significance and management. Como, W.A: Dept. of Conservation and Land Management, 1992.
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Conservation Commission of Western Australia. A review of high conservation value in Western Australia's south-west forests: A report to the Conservation Commission of Western Australia. Fremantle: Ecoscape, 2004.
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Grey, Kathleen. Miospore assemblages from the Devonian reef complexes, Canning Basin, Western Australia. Perth: State Print, 1992.
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Carr, William M. B. Exploration and mining in national parks and conservation reserves in western Australia. S.l: s.n, 1993.
Cerca il testo completoCapitoli di libri sul tema "Plant conservation – Western Australia"
1
Burbidge, Andrew, e Gordon Wyre. "Conservation of reptiles and frogs in Western Australia". In Herpetology in Australia, 43–48. P.O. Box 20, Mosman NSW 2088, Australia: Royal Zoological Society of New South Wales, 1993. http://dx.doi.org/10.7882/rzsnsw.1993.007.
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Pearson, David J. "Distribution, status and conservation of pythons in Western Australia". In Herpetology in Australia, 383–96. P.O. Box 20, Mosman NSW 2088, Australia: Royal Zoological Society of New South Wales, 1993. http://dx.doi.org/10.7882/rzsnsw.1993.062.
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Campbell, Andrew, Phil Grice e Justin Hardy. "26. Local Conservation Action in Western Australia". In Fertile Ground, 340–53. Rugby, Warwickshire, United Kingdom: Practical Action Publishing, 1999. http://dx.doi.org/10.3362/9781780444963.026.
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Armstrong, Kyle N. "The current status of bats in Western Australia". In The Biology and Conservation of Australasian Bats, 257–69. P.O. Box 20, Mosman NSW 2088, Australia: Royal Zoological Society of New South Wales, 2011. http://dx.doi.org/10.7882/fs.2011.026.
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Anderson, G. C., e I. R. P. Fillery. "Sulphate and nitrogen net mineralisation in coarse-textured soils in western Australia". In Plant Nutrition, 944–45. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/0-306-47624-x_460.
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Connell, Karen. "Marketing soil acidity knowledge in Western Australia". In Plant-Soil Interactions at Low pH: Principles and Management, 717–21. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0221-6_114.
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Whitford, Kim, e Geoff Stoneman. "Management of tree hollows in the jarrahEucalyptus marginata forest of Western Australia". In Conservation of Australia's Forest Fauna, 807–29. P.O. Box 20, Mosman NSW 2088: Royal Zoological Society of New South Wales, 2004. http://dx.doi.org/10.7882/fs.2004.049.
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McComb, A. J., e R. J. Lukatelich. "Nutrients and Plant Biomass in Australian Estuaries, with Particular Reference to South-western Australia". In Limnology in Australia, 433–55. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4820-4_27.
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Abbott, Ian, e Neil Burrows. "Monitoring biodiversity in jarrah forest in south-west Western Australia: the Forestcheck initiative". In Conservation of Australia's Forest Fauna, 947–58. P.O. Box 20, Mosman NSW 2088: Royal Zoological Society of New South Wales, 2004. http://dx.doi.org/10.7882/fs.2004.947.
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de Tores, Paul J., e Nicky Marlow. "The Relative Merits of Predator-Exclusion Fencing and Repeated Fox Baiting for Protection of Native Fauna: Five Case Studies from Western Australia". In Fencing for Conservation, 21–42. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4614-0902-1_3.
Testo completoAtti di convegni sul tema "Plant conservation – Western Australia"
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Lamoureux, Sebastian, Erik Veneklaas, Pieter Poot e Michael O’Kane. "The effect of cover system depth on native plant water relations in semi-arid Western Australia". In Mine Closure 2016. Australian Centre for Geomechanics, Perth, 2016. http://dx.doi.org/10.36487/acg_rep/1608_42_lamoureux.
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Peterseim, Juergen H., Amir Tadros, Udo Hellwig e Stuart White. "Integrated Solar Combined Cycle Plants Using Solar Towers With Thermal Storage to Increase Plant Performance". In ASME 2013 Power Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/power2013-98121.
Testo completoAbstract (sommario):
In Australia both natural gas and an excellent solar irradiance are abundant energy sources and its combination is one option to implement concentrating solar power (CSP) systems in Australia’s traditionally low cost electricity market. The recently introduced carbon pricing mechanism in Australia is likely to steer investment towards combined cycle gas turbine (CCGT) plants. This will also lead to further plants being built in high solar irradiance areas where CSP could provide valuable peak capacity. Hybridisation would enable more competitive power generation than standalone CSP systems as hybrid plants share equipment, such as steam turbine and condenser, therewith lowering the specific investment. This paper investigates the novel hybridization of CCGT and solar tower systems to increase the efficiency of integrated solar combined cycle (ISCC). Currently, all ISCC plants use parabolic trough systems with thermal oil as this technology is most mature. However, increases in plant efficiency, simpler solar tower integration as well as further synergies of solar tower ISCC systems, such as joint use of tower as CCGT stack, are likely to enhance the economic viability of new ISCC plants. In addition to a technical concept description this paper outlines the ideal sites for ISCC plants in Australia and presents a 200MWe ISCC case study with 3h molten salt thermal storage for the conversion of the Port Hedland open cycle gas turbine (OCGT) facility in Western Australia into a solar tower ISCC plant.
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Luo, Chengcai, Hongwei An, Liang Cheng e David White. "Calibration of UWA’s O-Tube Flume Facility". In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83274.
Testo completoAbstract (sommario):
The O-tube facility, designed and established at the University of Western Australia, is an innovative closed loop flume in which a random storm sequence can be reproduced via control of a large pump system. The O-tube facility is capable of simulating hydrodynamic conditions near the seabed and the interaction with seabed sediment and any infrastructure that is resting on it. The purpose of carrying out the O-tube calibration described in this paper is to obtain the relationship between the motor rotation movement and the flow velocity generated in the O-tube, such that any required storm history within the performance envelope of the O-tube can be reproduced. A range of flow velocities and the corresponding pump speeds were measured under steady current, oscillatory flow and combined flow conditions. It was found that the relationship between the pump speed and the flow velocity varies with the oscillatory flow period. Based on the pump characteristic curves and O-tube system curves, the correlation between the motor speed and the flow velocity was derived by applying hydraulic theory and the principle of energy conservation. The derived correlation is validated by reproducing a wide range of target storm series, including a (1:5.8) scaled 100-year return period storm from the North West Shelf of Western Australia in 40 m water depth.
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Boehm, B., e R. R. Marks. "Technical and Economical Aspects of Using Gas Turbine Technology in Eastern Europe Including the Commonwealth of Independent States (CIS)". In ASME 1992 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1992. http://dx.doi.org/10.1115/92-gt-353.
Testo completoAbstract (sommario):
An overview of the installed electrical generating capacity in the entire Eastern European region is given along with the plants intended for expansion to meet the forecasted system load demands. The emphasis with future power plants in the region will be attached to attaining considerably higher generating efficiency and operating availability than are presently being achieved, as well as to directly reducing pollutant emissions to protect the environment more effectively. Modern Western technology will be adopted on a certain scale to meet the objectives of better economy and ecological conservation. In many cases this will be accomplished by cooperating with Western companies to ensure long-term technology transfer. In particular, many of the new power plants required will be built in the form of combined-cycle installations. Gas turbines may in some cases be retrofitted to existing reheat steam boiler/turbine units (topping or repowering) to improve overall station efficiency. Particular power plant projects in Eastern Europe including the Commonwealth of Independent States are presented as examples of typical solutions to achieving the goals that are so important to the region.
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Blinderman, Michael S., e Bernard Anderson. "Underground Coal Gasification for Power Generation: High Efficiency and CO2-Emissions". In ASME 2004 Power Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/power2004-52036.
Testo completoAbstract (sommario):
Underground Coal Gasification (UCG) is a gasification process carried out in non-mined coal seams using injection and production wells drilled from the surface, enabling the coal to be converted into product gas. The UCG process practiced by Ergo Exergy is called Exergy UCG or εUCG. εUCG was applied in the Chinchilla UCG-IGCC Project in Australia. The IGCC project in Chinchilla, Australia has been under development since July 1999. The project involves construction of the underground gasifier and demonstration of UCG technology, and installation of the power island. Since December 1999 the plant has been making gas continuously, and its maximum capacity is 80,000 Nm3/h. Approximately 32,000 tonnes of coal have been gasified, and 100% availability of gas production has been demonstrated over 30 months of operation. The UCG operation in Chinchilla is the largest and the longest to date in the Western world. The εUCG facility at Chinchilla has used air injection, and produced a low BTU gas of about 5.0 MJ/m3 at a pressure of 10 barg (145 psig) and temperature of 300° C (570° F). It included 9 process wells that have been producing gas manufactured from a 10 m thick coal seam at the depth of about 140 m. The process displayed high efficiency and consistency in providing gas of stable quality and quantity. The results of operations in Chinchilla to date have demonstrated that εUCG can consistently provide gas of stable quantity and quality for IGCC power projects at very low cost enabling the UCG-IGCC plant to compete with coal-fired power stations. This has been done in full compliance with rigorous environmental regulations. A wide range of gas turbines can be used for UCG-IGCC applications. The turbines using UCG gas will demonstrate an increase in output by up to 25% compared to natural gas. The power block efficiency reaches 55%, while the overall efficiency of the UCG-IGCC process can reach 43%. A UCG-IGCC power plant will generate electricity at a much lower cost than existing or proposed fossil fuel power plants. CO2 emissions of the plant can be reduced to a level 55% less than those of a supercritical coal-fired plant and 25% less than the emissions of NG CC.
Rapporti di organizzazioni sul tema "Plant conservation – Western Australia"
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A decade of science support in the sagebrush biome (NOTE: to be released late September 2021). Natural Resources Conservation Service, settembre 2021. http://dx.doi.org/10.32747/2021.7488985.
Testo completoAbstract (sommario):
Working Lands for Wildlife (WLFW) invests in science to proactively target conservation investments and quantify outcomes. This report summarizes more than a decade of WLFW science’s current understanding of identified sagebrush biome threats on western working rangelands and how best to address them through voluntary conservation actions. More than 350 plant and animal species are benefitting from this conservation, notably sage grouse, sagebrush songbirds, and migratory big game populations. 61 peer-reviewed publications are referenced in the report that are helping guide targeted conservation of the sage brush biome, conserve core areas, along with scientifically quantifying outcomes.