845 resultados para Southern Australia
Resumo:
The aim of this work is to develop a Demand-Side-Response (DSR) model, which assists electricity end-users to be engaged in mitigating peak demands on the electricity network in Eastern and Southern Australia. The proposed innovative model will comprise a technical set-up of a programmable internet relay, a router, solid state switches in addition to the suitable software to control electricity demand at user's premises. The software on appropriate multimedia tool (CD Rom) will be curtailing/shifting electric loads to the most appropriate time of the day following the implemented economic model, which is designed to be maximizing financial benefits to electricity consumers. Additionally the model is targeting a national electrical load be spread-out evenly throughout the year in order to satisfy best economic performance for electricity generation, transmission and distribution. The model is applicable in region managed by the Australian Energy Management Operator (AEMO) covering states of Eastern-, Southern-Australia and Tasmania.
Resumo:
Spinosad was proposed as a potential chemical for control of lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), in Australian broiler houses after the detection of strong cyfluthrin resistance in many beetle populations. In 2004-2006, spinosad susceptibility of 13 beetle populations from eastern and southern Australian broiler houses and a cyfluthrin/fenitrothion-resistant reference population was determined using topical application, and was compared with the susceptibility of an insecticide-susceptible reference population. Comparisons of dose-response curves and baseline data showed that all populations, including the insecticide-susceptible population, were roughly equivalent in their response to spinosad, indicating no preexisting spinosad resistance. Two field populations, including the resistant reference population, which had confirmed cyfluthrin/fenitrothion- resistance, showed no cross-resistance to spinosad. There was no significant correlation between beetle weight and LC99.9. A discriminating concentration of 3% spinosad was set to separate resistant and susceptible individuals. Considering the levels of spinosad resistance that have been recorded in other insect pests, the sustained future usefulness of spinosad as a broiler house treatment will rely on effective integrated beetle management programs combined with carefully planned chemical use strategies.
Resumo:
From 27 January to 8 February during the summer of 2009, southern Australia experienced one of the nation‘s most severe heatwaves. Governments, councils, utilities, hospitals and emergency response organisations and the community were largely underprepared for an extreme event of this magnitude. This case study targets the experience and challenges faced by decision makers and policy makers and focuses on the major metropolitan areas affected by the heatwave — Melbourne and Adelaide. The study examines the 2009 heatwave‘s characteristics; its impacts (on human health, infrastructure and human services); the degree of adaptive capacity (vulnerability and resilience) of various sectors, communities and individuals; and the reactive responses of government and emergency and associated services and their effectiveness. Barriers and challenges to adaptation and increasing resilience are also identified and further areas for research are suggested. This study does not include details of the heatwave‘s effects beyond Victoria and South Australia, or its economic impacts, or of Victoria‘s 'Black Saturday‘ bushfires.
Resumo:
The occurrence of extreme water levels along low-lying, highly populated and/or developed coastlines can lead to considerable loss of life and billions of dollars of damage to coastal infrastructure. Therefore it is vitally important that the exceedance probabilities of extreme water levels are accurately evaluated to inform risk-based flood management, engineering and future land-use planning. This ensures the risk of catastrophic structural failures due to under-design or expensive wastes due to over-design are minimised. This paper estimates for the first time present day extreme water level exceedence probabilities around the whole coastline of Australia. A high-resolution depth averaged hydrodynamic model has been configured for the Australian continental shelf region and has been forced with tidal levels from a global tidal model and meteorological fields from a global reanalysis to generate a 61-year hindcast of water levels. Output from this model has been successfully validated against measurements from 30 tide gauge sites. At each numeric coastal grid point, extreme value distributions have been fitted to the derived time series of annual maxima and the several largest water levels each year to estimate exceedence probabilities. This provides a reliable estimate of water level probabilities around southern Australia; a region mainly impacted by extra-tropical cyclones. However, as the meteorological forcing used only weakly includes the effects of tropical cyclones, extreme water level probabilities are underestimated around the western, northern and north-eastern Australian coastline. In a companion paper we build on the work presented here and more accurately include tropical cyclone-induced surges in the estimation of extreme water level. The multi-decadal hindcast generated here has been used primarily to estimate extreme water level exceedance probabilities but could be used more widely in the future for a variety of other research and practical applications.
Resumo:
Wheat is one of the major food crops in the world. It is Australia's largest crop and most important agricultural commodity. In Australia the crop is grown under rainfed conditions with inherently important regional environmental differences; wheat growing areas are characterized by winter dominant rainfall in southern and western Australia and summer rainfall in northern Australia. Maximizing yield potential across these diverse regions is dependent upon managing, either genetically or agronomically, those factors in the environment that limit yield. The potential of synthetic backcross lines (SBLs) to increase yield in the diverse agroecological zones of Australia was investigated. Significant yield advantages were found for many of the SBLs across diverse environments. Depending on the environment, the yield of the SBLs ranged from 8% to 30% higher than the best local check in Australia. Apart from adaptation to semiarid water stressed conditions, some SBLs were also found to be significantly higher yielding under more optimal (irrigated) conditions. The four testing environments were classified into two groups, with the northern and southern environments being in separate groups. An elite group of SBLs was identified that exhibited broad adaptation across all diverse Australian environments included in this study. Other SBLs showed specific adaptation to either northern or southern Australia. This study showed that SBLs are likely to provide breeders with the opportunity to significantly improve wheat yield beyond what was previously possible in a number of diverse production environments.
Resumo:
Synthetic backcrossed-derived bread wheats (SBWs) from CIMMYT were grown in the north-west of Mexico (CIANO) and sites across Australia during 3 seasons. A different set of lines was evaluated each season, as new materials became available from the CIMMYT crop enhancement program. Previously, we have evaluated both the performance of genotypes across environments and the genotype x environment interaction (G x E). The objective of this study was to interpret the G x E for yield in terms of crop attributes measured at individual sites and to identify the potential environmental drivers of this interaction. Groups of SBWs with consistent yield performance were identified, often comprising closely related lines. However, contrasting performance was also relatively common among sister lines or between a recurrent parent and its SBWs. Early flowering was a common feature among lines with broad adaptation and/or high yield in the northern Australian wheatbelt, while yields in the southern region did not show any association with the maturity type. Lines with high yields in the southern and northern regions had cooler canopies during flowering and early grain filling. Among the SBWs with Australian genetic backgrounds, lines best adapted to CIANO were tall (>100 cm), with a slightly higher ground cover. These lines also displayed a higher concentration of water-soluble carbohydrates in the stem at flowering, which was negatively correlated with stem number per unit area when evaluated in southern Australia (Horsham). Possible reasons for these patterns are discussed. Selection for yield at CIANO did not specifically identify the lines best adapted to northern Australia, although they were not the most poorly adapted either. In addition, groups of lines with specific adaptation to the south would not have been selected by choosing the highest yielding lines at CIANO. These findings suggest that selection at CIMMYT for Australian environments may be improved by either trait based selection or yield data combined with trait information. Flowering date, canopy temperature around flowering, tiller density, and water-soluble carbohydrate concentration in the stem at flowering seem likely candidates.
Resumo:
Climate change projections for Australia predict increasing temperatures, changes to rainfall patterns, and elevated atmospheric carbon dioxide (CO2) concentrations. The aims of this study were to predict plant production responses to elevated CO2 concentrations using the SGS Pasture Model and DairyMod, and then to quantify the effects of climate change scenarios for 2030 and 2070 on predicted pasture growth, species composition, and soil moisture conditions of 5 existing pasture systems in climates ranging from cool temperate to subtropical, relative to a historical baseline. Three future climate scenarios were created for each site by adjusting historical climate data according to temperature and rainfall change projections for 2030, 2070 mid-and 2070 high-emission scenarios, using output from the CSIRO Mark 3 global climate model. In the absence of other climate changes, mean annual pasture production at an elevated CO2 concentration of 550 ppm was predicted to be 24-29% higher than at 380 ppm CO2 in temperate (C-3) species-dominant pastures in southern Australia, with lower mean responses in a mixed C-3/C-4 pasture at Barraba in northern New South Wales (17%) and in a C-4 pasture at Mutdapilly in south-eastern Queensland (9%). In the future climate scenarios at the Barraba and Mutdapilly sites in subtropical and subhumid climates, respectively, where climate projections indicated warming of up to 4.4 degrees C, with little change in annual rainfall, modelling predicted increased pasture production and a shift towards C-4 species dominance. In Mediterranean, temperate, and cool temperate climates, climate change projections indicated warming of up to 3.3 degrees C, with annual rainfall reduced by up to 28%. Under future climate scenarios at Wagga Wagga, NSW, and Ellinbank, Victoria, our study predicted increased winter and early spring pasture growth rates, but this was counteracted by a predicted shorter spring growing season, with annual pasture production higher than the baseline under the 2030 climate scenario, but reduced by up to 19% under the 2070 high scenario. In a cool temperate environment at Elliott, Tasmania, annual production was higher than the baseline in all 3 future climate scenarios, but highest in the 2070 mid scenario. At the Wagga Wagga, Ellinbank, and Elliott sites the effect of rainfall declines on pasture production was moderated by a predicted reduction in drainage below the root zone and, at Ellinbank, the use of deeper rooted plant systems was shown to be an effective adaptation to mitigate some of the effect of lower rainfall.
Resumo:
To adapt to climate variability and a lack of irrigation water, businesses and growers in southern Australia, northern New South Wales and southern Queensland are, or are considering, migrating their businesses to northern Australia.
Resumo:
Post head-emergence frost causes substantial losses for Australian barley producers. Varieties with improved resistance would have a significant positive impact on Australian cropping enterprises. Five barley genotypes previously tested for reproductive frost resistance in southern Australia were tested, post head-emergence, in the northern grain region of Australia and compared with the typical northern control cultivars, Gilbert and Kaputar. All tested genotypes suffered severe damage to whole heads and stems at plant minimum temperatures less than -8degreesC. In 2003, 2004 and 2005, frost events reaching a plant minimum temperature of ~-6.5degreesC did not result in the complete loss of grain yield. Rather, partial seed set was observed. The control genotype, Gilbert, exhibited seed set that was greater than or equal to that of any genotype in each year, as did Kaputar when tested in 2005. Thus, Gilbert and Kaputar were at least as resistant as any tested genotype. This contrasts with trial results from the southern grain region where Gilbert was reported to be less resistant than Franklin, Amagi Nijo and Haruna Nijo. Hence, rankings for post head-emergence frost damage in the northern grain region differ from those previously reported. These results indicate that Franklin, Amagi Nijo and Haruna Nijo are not likely to provide useful sources of frost resistance or markers to develop improved varieties for the northern grain region of Australia.
Resumo:
Given the limited resources available for weed management, a strategic approach is required to give the best bang for your buck. The current study incorporates: (1) a model ensemble approach to identify areas of uncertainty and commonality regarding a species invasive potential, (2) current distribution of the invaded species, and (3) connectivity of systems to identify target regions and focus efforts for more effective management. Uncertainty in the prediction of suitable habitat for H. amplexicaulis (study species) in Australia was addressed in an ensemble-forecasting approach to compare distributional scenarios from four models (CLIMATCH; CLIMEX; boosted regression trees [BRT]; maximum entropy [Maxent]). Models were built using subsets of occurrence and environmental data. Catchment risk was determined through incorporating habitat suitability, the current abundance and distribution of H. amplexicaulis, and catchment connectivity. Our results indicate geographic differences between predictions of different approaches. Despite these differences a number of catchments in northern, central, and southern Australia were identified as high risk of invasion or further spread by all models suggesting they should be given priority for the management of H. amplexicaulis. The study also highlighted the utility of ensemble approaches in indentifying areas of uncertainty and commonality regarding the species invasive potential.
Resumo:
Fishery-independent estimates of spawning biomass (BSP) of the Pacific sardine (Sardinops sagax) on the south and lower west coasts of Western Australia (WA) were obtained periodically between 1991 and 1999 by using the daily egg production method (DEPM). Ichthyoplankton data collected during these surveys, specifically the presence or absence of S. sagax eggs, were used to investigate trends in the spawning area of S. sagax within each of four regions. The expectation was that trends in BSP and spawning area were positively related. With the DEPM model, estimates of BSP will change proportionally with spawning area if all other variables remain constant. The proportion of positive stations (PPS), i.e., stations with nonzero egg counts — an objective estimator of spawning area — was high for all south coast regions during the early 1990s (a period when the estimated BSP was also high) and then decreased after the mid-1990s. There was a decrease in PPS from the mid-1990s to 1999. The particularly low estimates in 1999 followed a severe epidemic mass mortality of S. sagax throughout their range across southern Australia. Deviations from the expected relationship between BSP and PPS were used to identify uncertainty around estimates of BSP. Because estimation of spawning area is subject to less sampling bias than estimation of BSP, the deviation in the relation between the two provides an objective basis for adjusting some estimates of the latter. Such an approach is particularly useful for fisheries management purposes when sampling problems are suspected to be present. The analysis of PPS undertaken from the same set of samples from which the DEPM estimate is derived will help provide information for stock assessments and for the management of purse-seine fisheries.
Resumo:
Larval development of the southern sea garfish (Hyporhamphus melanochir) and the river garfish (H. regularis) is described from specimens from South Australian waters. Larvae of H. melanochir and H. regularis have completed notochord flexion at hatching and are characterized by an elongate body with distinct rows of melanophores along the dorsal, lateral, and ventral surfaces; a small to moderate head; a heavily pigmented and long straight gut; a persistent pre-anal finfold; and an extended lower jaw. Fin formation occurs in the following sequence: caudal, dorsal and anal (almost simultaneously), pectoral, and pelvic. Despite the similarities between both species and among hemiramphid larvae in general, H. melanochir larvae are distinguishable from H. regularis by 1) having 58–61 vertebrae (vs. 51–54 for H. regularis); 2) having 12–15 melanophore pairs in longitudinal rows along the dorsal margin between the head and origin of the dorsal fin (vs. 19–22 for H. regularis); and 3) the absence of a large ventral pigment blotch anteriorly on the gut and isthmus (present in H. regularis). Both species can be distinguished from similar larvae of southern Australia (other hemiramphids and a scomberosocid) by differences in meristic counts and pigmentation.
Resumo:
1. Blue whale locations in the Southern Hemisphere and northern Indian Ocean were obtained from catches (303 239), sightings (4383 records of ≥ 8058 whales), strandings (103), Discovery marks (2191) and recoveries (95), and acoustic recordings. 2. Sighting surveys included 7 480 450 km of effort plus 14 676 days with unmeasured effort. Groups usually consisted of solitary whales (65.2%) or pairs (24.6%); larger feeding aggregations of unassociated individuals were only rarely observed. Sighting rates (groups per 1000 km from many platform types) varied by four orders of magnitude and were lowest in the waters of Brazil, South Africa, the eastern tropical Pacific, Antarctica and South Georgia; higher in the Subantarctic and Peru; and highest around Indonesia, Sri Lanka, Chile, southern Australia and south of Madagascar. 3. Blue whales avoid the oligotrophic central gyres of the Indian, Pacific and Atlantic Oceans, but are more common where phytoplankton densities are high, and where there are dynamic oceanographic processes like upwelling and frontal meandering. 4. Compared with historical catches, the Antarctic (‘true’) subspecies is exceedingly rare and usually concentrated closer to the summer pack ice. In summer they are found throughout the Antarctic; in winter they migrate to southern Africa (although recent sightings there are rare) and to other northerly locations (based on acoustics), although some overwinter in the Antarctic. 5. Pygmy blue whales are found around the Indian Ocean and from southern Australia to New Zealand. At least four groupings are evident: northern Indian Ocean, from Madagascar to the Subantarctic, Indonesia to western and southern Australia, and from New Zealand northwards to the equator. Sighting rates are typically much higher than for Antarctic blue whales.
Resumo:
The research presented indicates that lucerne crown and root rot caused by Stagonospora meliloti is prevalent in southern New South Wales, whereas Acrocalymma medicaginis is the more commonly observed pathogen in Queensland. Although both pathogens cause reddening of internal root and crown tissue of lucerne, they can be distinguished by symptomatology. S. meliloti causes a diffuse red blotching of the internal tissue accompanied by the presence of an external lesion, whereas A. medicaginis causes red streaking at the extremity of wedge-shaped, dry-rotted tissue. Inoculation of propagules of a susceptible lucerne clone indicated that S. meliloti was the more aggressive pathogen. Although A. medicaginis does not cause leaf disease, there was a strong relationship between the leaf and root reaction of clones to S. meliloti. Inheritance of resistance to S. meliloti in lucerne appeared to be conditioned by a single dominant gene, based on segregations observed in S-1 and F-1 populations, but not in a backcross population from the same family where an excess of susceptible individuals (74% v. expected of 50%) was obtained in a cross of a resistant F-1 individual to the susceptible parent. Resistance appears to be highly heritable, however, and amenable to population improvement by breeding. A conclusion of the research is that breeding for resistance to S. meliloti for lucernes to be grown in southern Australia would appear to be a worthwhile objective. Presently, no highly resistant cultivars exist anywhere in the world.