688 resultados para Turtles -- Ecology -- Australia
Resumo:
Determining the ecologically relevant spatial scales for predicting species occurrences is an important concept when determining species–environment relationships. Therefore species distribution modelling should consider all ecologically relevant spatial scales. While several recent studies have addressed this problem in artificially fragmented landscapes, few studies have researched relevant ecological scales for organisms that also live in naturally fragmented landscapes. This situation is exemplified by the Australian rock-wallabies’ preference for rugged terrain and we addressed the issue of scale using the threatened brush-tailed rock-wallaby (Petrogale penicillata) in eastern Australia. We surveyed for brush-tailed rock-wallabies at 200 sites in southeast Queensland, collecting potentially influential site level and landscape level variables. We applied classification trees at either scale to capture a hierarchy of relationships between the explanatory variables and brush-tailed rock-wallaby presence/absence. Habitat complexity at the site level and geology at the landscape level were the best predictors of where we observed brush-tailed rock-wallabies. Our study showed that the distribution of the species is affected by both site scale and landscape scale factors, reinforcing the need for a multi-scale approach to understanding the relationship between a species and its environment. We demonstrate that careful design of data collection, using coarse scale spatial datasets and finer scale field data, can provide useful information for identifying the ecologically relevant scales for studying species–environment relationships. Our study highlights the need to determine patterns of environmental influence at multiple scales to conserve specialist species such as the brush-tailed rock-wallaby in naturally fragmented landscapes.
Resumo:
Paropsis atomaria is a recently emerged pest of eucalypt plantations in subtropical Australia. Its broad host range of at least 20 eucalypt species and wide geographical distribution provides it the potential to become a serious forestry pest both within Australia and, if accidentally introduced, overseas. Although populations of P. atomaria are genetically similar throughout its range, population dynamics differ between regions. Here, we determine temperature-dependent developmental requirements using beetles sourced from temperate and subtropical zones by calculating lower temperature thresholds, temperature-induced mortality, and day-degree requirements. We combine these data with field mortality estimates of immature life stages to produce a cohort-based model, ParopSys, using DYMEX™ that accurately predicts the timing, duration, and relative abundance of life stages in the field and number of generations in a spring–autumn (September–May) field season. Voltinism was identified as a seasonally plastic trait dependent upon environmental conditions, with two generations observed and predicted in the Australian Capital Territory, and up to four in Queensland. Lower temperature thresholds for development ranged between 4 and 9 °C, and overall development rates did not differ according to beetle origin. Total immature development time (egg–adult) was approximately 769.2 ± S.E. 127.8 DD above a lower temperature threshold of 6.4 ± S.E. 2.6 °C. ParopSys provides a basic tool enabling forest managers to use the number of generations and seasonal fluctuations in abundance of damaging life stages to estimate the pest risk of P. atomaria prior to plantation establishment, and predict the occurrence and duration of damaging life stages in the field. Additionally, by using local climatic data the pest potential of P. atomaria can be estimated to predict the risk of it establishing if accidentally introduced overseas. Improvements to ParopSys’ capability and complexity can be made as more biological data become available.
Resumo:
Polyfluoroalkyl chemicals (PFCs) have been used worldwide for more than 50 years in a wide variety of industrial and consumer products. Limited data exist on human exposure to PFCs in the Southern Hemisphere. Human blood serum collected in southeast Queensland, Australia, in 2006−2007 from 2420 donors was pooled according to age (cord blood, 0−0.5, 0.6−1, 1.1−1.5, 1.6−2, 2.1−2.5, 2.6−3, 3.1−3.5, 3.6−4, 4.1−6, 6.1−9, 9.1−12, 12.1−15, 16−30, 31−45, 46−60, and >60 years) and gender and was analyzed for eight PFCs. Across all pools, perfluorooctane sulfonate (PFOS) was detected at the highest mean concentration (15.2 ng/mL) followed by perfluorooctanoate (PFOA, 6.4 ng/mL), perfluorohexane sulfonate (PFHxS, 3.1 ng/mL), perfluorononanoate (PFNA, 0.8 ng/mL), 2-(N-methyl-perfluorooctance sulfonamide) acetate (Me-PFOSA-AcOH, 0.66 ng/mL), and perfluorodecanoate (PFDeA, 0.29 ng/mL). Perfluorooctane sulfonamide was detected in only 24% of the pools, and 2-(N-ethylperfluorooctane sulfonamide) acetate was detected in only one. PFOS concentrations were significantly higher in pools from adult males than from adult females (p = 0.002); no gender differences were apparent in the pools from children (<12 years old). The highest mean concentrations of PFOA, PFHxS, PFNA, PFDeA, and Me-PFOSA-AcOH were found in children <15 years, while PFOS was highest in adults >60 years. Investigation into the sources and exposure pathways in Australia, in particular for children, is necessary as well as continued biomonitoring to determine the potential effects on human concentrations as a result of changes in the PFC manufacturing practices, including the cessation of production of several PFCs.
Resumo:
The relationship between employers and employees has been one of the most hotly debated issues in Australia in recent times. Recent legislation such as the Workplace Relations Amendment (Work Choices) Act 2005 and the subsequent Fair Work Act 2009 provides stark evidence of this. The impact of these significant developments is explored and analysed in detail in the new edition of this popular text, complete with a balanced coverage of the often contrasting viewpoints of all stakeholders - from governments, unions and employer associations, through to individual employers and employees. The text outlines different approaches to understanding the nature of the employment relationship, with a contextual background as to how this relationship has changed and developed throughout our nation's history.
Resumo:
This book chapter considers recent developments in Australia and key jurisdictions both in relation to the formation of a national information strategy and the management of legal rights in public sector information.
Resumo:
This paper presents results from three studies in 25 custodial facilities in three Australian states, including nutrient analyses of menus and focus groups exploring inmate attitudes. Both cook-fresh and cook-chill production systems are used. Non-selective cycle menus of 4-6 weeks are common but inmates can supplement meals by purchase of additional food items (‘buy-ups’). Menus included adequate variety and met most nutritional standards, with the possible exception of fruit. The sodium content of menus is above recommended levels. Protein, fibre, vitamins A, C, thiamin, riboflavin, calcium, iron and zinc were more than adequate, and the percentage energy from fat is close to or meets national recommendations. Focus groups identified 16 themes, including meal quality, food available at ‘buy-ups’, cooking facilities, and concerns about possible food safety risks associated with inmates storing food in cells. Many complaints were about factors not under the control of the foodservice manager.
Resumo:
This paper reports research undertaken as part of a larger project in which we examined whether and how values and beliefs communicated by Australian politicians have shaped decades of health policy and influenced health outcomes for Aboriginal and Torres Strait Islander Peoples of Australia. To first characterise those values and beliefs we analysed the public statements of the politicians responsible nationally for the health of Aboriginal and Torres Strait Islander Peoples 1972–2001, using critical discourse analysis. We found that four discourses, communicated through words, phrases, sentences and grammatical structures, dominated public statements over the study period. These four discourses focused on the competence and capacity of Aboriginal and Torres Strait Islander Peoples to “manage”; matters of control of and responsibility for the health of Aboriginal and Torres Strait Islander Peoples; Aboriginal and Torres Strait Islander Peoples as “Other”; and the nature of the “problem” concerning the health of Aboriginal and Torres Strait Islander Peoples. Analysis of the discursive elements contributing to shaping these four discourses is reported in this paper.