990 resultados para Wetland ecology - Western Australia


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Soil organic matter (SOM) increases with time as landscape is restored. Studying SOM development along restored forest chronosequences would be useful in clarifying some of the uncertainties in quantifying C turnover rates with respect to forest clearance and ensuing restoration. The development of soil organic matter in the mineral soils was studied at four depths in a 16-year-old restored jarrah forest chronosequence. The size-separated SOM fractionation along with δ13C isotopic shift was utilised to resolve the soil C temporal and spatial changes with developing vegetation. The restored forest chronosequence revealed several important insights into how soil C is developing with age. Litter accumulation outpaced the native forest levels in 12 years after restoration. The surface soils, in general, showed increase in total C with age, but this trend was not clearly observed at lower depths. C accumulation was observed with increasing restoration age in all three SOM size-fractions in the surface 0–2 cm depth. These biodiverse forests show a trend towards accumulating C in recalcitrant stable forms, but only in the surface 0–2 cm mineral soil. A significant reverse trend was observed for the moderately labile SOM fraction for lower depths with increasing restoration age. Correlating the soil δ13C with total C concentration revealed the re-establishment of the isotopically depleted labile to enriched refractory C continuum with soil depth for the older restored sites. This implied that from a pedogenic perspective, the restored soils are developing towards the original native soil carbon profile.

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We predicted that P-fertiliser residues will limit the establishment of native plant species and their mycorrhizas to old-fields in the wheat-growing region (i.e. the wheatbelt) of Western Australia. To test this prediction, we assessed the growth and P uptake of seedlings of three native plant species to phosphate addition and inoculation with arbuscular mycorrhizas (AM) in a pot study. The native plant species were Acacia acuminata Benth. (Mimosaceae), Eucalyptus loxophleba Benth. subsp. loxophleba (Myrtaceae) and Hakea preissii Meisn. (Proteaceae); and each pot contained one seedling. P was added to field soil to mimic pre-agricultural (P0), old-field (P1) and 10 times old-field (P10) soils. AM inoculant, which was a mix of Scutellospora calospora (Nicolson and Gerdemann) Walker and Sanders, Glomus intraradices Schenck and Smith and Glomus mosseae (Nicolson and Gerdemann) Gerdemann and Trappe, was added to half of the pots. After 12 weeks, the biomass and P uptake of the mycorrhizal A. acuminata were greater than those of the non-mycorrhizal plants across all P treatments. Plant biomass decreased significantly with increasing P addition, yet this species was apparently unable to suppress its mycorrhizal colonisation at high P despite this reduction in growth. In contrast, mycorrhizal and non-mycorrhizal E. loxophleba subsp. loxophleba were of a similar biomass after 12 weeks; maximum biomass was attained at intermediate (old-field) levels of P. P uptake increased with increasing P supply, beyond that required to attain maximum biomass. AM did not form on H. preissii. P uptake increased with increasing P supply for this species also. Overall, it is the apparent inability of these species to down-regulate P uptake rather than a lack of mycorrhizal symbiosis that will constrain their establishment on wheatbelt old-fields.

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The marron, Cherax tenuimanus (Smith), is one of the most easily recognisable members of the freshwater crayfish genus Cherax. Since its description in 1912, the taxonomy of the species has not been in dispute, but recent genetic studies have demonstrated that the species is not homogenous and consists of two genetically distinct forms. One of these forms is widespread and exploited via aquaculture and the other is restricted to a single river system, the Margaret River. This paper presents allozyme data, collected over a 19-year period, which documents the introduction of the widespread form into the Margaret River and the subsequent reproductive interactions between the two forms. These data indicate minimal interbreeding between the two forms of marron and so justify their recognition as distinct species. As the original description of the marron was based on specimens collected from the Margaret River, the form native to this river retains the name C. tenuimanus and a new species, Cherax cainii Austin is described for the common, widespread form of marron. An additional outcome of this study is that C. tenuimanus has been rapidly displaced by the introduced C. cainii within the Margaret River. Consequently, urgent conservation measures are required to protect C. tenuimanus and prevent its possible extinction.

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Objective: To determine the relationship between personal, hormonal and lifestyle risk factors and surgically treated benign prostatic hyperplasia (BPH). Materials and methods: A population-based case–control study was conducted in Western Australia (WA) on men aged 40–75 years who were surgically treated at public and private hospitals for BPH during 2001–2002. Controls were recruited from the WA electoral roll. Cases and controls were compared with regard to demographic and lifestyle factors and proxy measures of hormonal status using logistic regression. Data were available for 398 cases and 471 controls. Results: No associations with BPH were found for family history of prostate cancer in father or brother, serving in the military in a combat area, pattern of baldness, smoking status, obesity, alcohol intake and occupational physical activity. The only inverse relationship was observed with heavy alcohol drinking (>30 g/day), however, this was not statistically significant. An increased risk of BPH, not statistically significant, was observed for British-born men compared to Australian born and for history of vasectomy. The analysis was repeated after excluding 28% of controls with moderate and severe symptoms of BPH and 7% of cases with mild symptoms prior to surgery, and our results remained essentially unchanged. Conclusions:The results suggest that there are few risk factors for BPH although perhaps country of birth, vasectomy and heavy alcohol consumption may be considered further.

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Recent sediment samples recovered from the mid-latitude South West Shelf (SWS) of Western Australia (23°- 32° S) by a scientific team aboard the RV Franklin have produced large numbers of free-living, lunulitiform bryozoans. Among these are three undescribed species, Otionellina boneae sp. nov., Selenaria kayae sp. nov., and Selenaria meganae sp. nov. The Australasian lunulite fauna is both diverse and abundant and the new species bring the total of described taxa to sixty (P. Cook unpub.). Twelve lunulite species have been recorded from the SWS. These findings have extended the known geographical range of several lunulite species.

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A unique marine Permian-Triassic boundary section containing rich oil source rocks has been continuously cored in a petroleum borehole from the Perth Basin of Western Australia. Such sequences, which provide a biostratigraphic and environmental record at the time of the largest extinction event of the past 500 million years, are globally rare, and this is the first to be documented in Australia. Throughout geological history there have been periods of global marine anoxia that commonly resulted in the widespread deposition of petroleum source rocks, most notably in the mid-Cretaceous and Late Jurassic. An apparent paradox is that, previously, source rocks have not been recognised in association with the Permian-Triassic boundary, despite widespread marine anoxia at this time. The Perth Basin source rocks contain abundant and unusual biomarkers, apparently related to the highly specialised and limited biota that flourished in the aftermath of the end-Permian extinction event. Local conditions may have favoured source-rock development, either due to higher productivity resulting from coastal upwelling or through enhanced preservation under strongly anoxic conditions.

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Objectives.
To describe the design and baseline results of an evaluation of the Western Australian government's pedestrian-friendly subdivision design code (Liveable Neighborhood (LN) Guidelines).
Methods.

Baseline results (2003–2005) from a longitudinal study of people (n = 1813) moving into new housing developments: 18 Liveable, 11 Hybrid and 45 Conventional (i.e., LDs, HDs and CDs respectively) are presented including usual recreational and transport-related walking undertaken within and outside the neighborhood, and 7-day pedometer steps.
Results.

At baseline, more participants walked for recreation and transport within the neighborhood (52.6%; 36.1% respectively), than outside the neighborhood (17.7%; 13.2% respectively). Notably, only 20% of average total duration of walking (128.4 min/week (SD159.8)) was transport related and within the neighborhood. There were few differences between the groups' demographic, psychosocial and perceived neighborhood environmental characteristics, pedometer steps, or the type, amount and location of self-reported walking (p > 0.05). However, asked what factors influenced their choice of housing development, more participants moving into LDs reported aspects of their new neighborhood's walkability as important (p < 0.05).
Conclusions.

The baseline results underscore the desirability of incorporating behavior and context-specific measures and value of longitudinal designs to enable changes in behavior, attitudes, and urban form to be monitored, while adjusting for baseline residential location preferences.

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Background: The introduction of the Australia Council's 'Arts in a Multicultural Australia Policy' (AIMAP) (2000) represented a shift in how the arts in multicultural communities were viewed. It has long been recognised that the arts play a significant role in promoting social cohesion, social policy goals, economic growth, and shaping a nation’s sense of identity. However, prior to the introduction of this policy, multicultural arts was typically seen as involving cultural retentive activities which had their roots in expressions of migrant cultural traditions. The introduction of the policy heralded the beginning of an era in which culturally and linguistically diverse (CaLD) Australians were seen as integral to the fabric of the Australian arts sector. Evaluation of the policy in 2005 however, revealed that culturally and linguistically diverse Australians were under-represented in most artistic categories. Western Australia is the most culturally diverse state in Australia. It is therefore of great interest to the State Government to have a comprehensive picture of the situation in that state. Hence, the Office of Multicultural Interests (OMI) commissioned Deakin University to undertake an investigation into the participation rates of CaLD artists in the arts sector in Western Australia.

Scope: The project examined the participation in the arts of CaLD artists in Western Australia. The arts sector comprises many more individuals and organisations than artists. For example, there are arts agency administrators, venue operators, policy officers, curators, and countless others who work together to make up the arts sector. This project focused on the artists, the individuals such as those who make music, visual art, dance and theatre performances. In the past it has been shown that CaLD populations are not well represented in the broader arts sector. This research aimed to discover the current position for CaLD artists in terms of participation in the broader arts sector and what factors influence their situation.

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This symposium explores policy, organisational, practice, and research issues in the delivery of legally mandated programs for men who have acted violently in their intimate relationships. It will draw on the findings of a collaborative project between corrections and a number of non-government agencies contracted to provide services. The paper will provide an overview of some of the systemic and policy issues that impact upon on program delivery and evaluation issues, and the experiences of female partners of men attending programs.

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