Time filter

Source Type

East Melbourne, Australia

Hurst T.,Melbourne Water | Boon P.I.,Victoria University of Melbourne
Australian Journal of Botany | Year: 2016

It is often assumed that saline coastal wetlands experience environmental conditions so severe that they are largely immune to invasion by exotic plant species. The belief is implicit in many older reviews of threats to mangroves and coastal saltmarshes, where a limited range of vascular plant taxa, often focussing on∗Spartina, (throughout the paper an asterisk denotes an introduced (exotic) species as per Carr 2012) have been invoked as the major species of concern. Even though the weed flora of southern Australia is derived largely from agriculture and horticulture, neither of which includes many species tolerant of waterlogged, variably saline environments, a recent assessment of Victorian saline coastal wetlands indicated that exotic plants were the third-most pervasive threat, after land 'reclamation' and grazing. Tall wheat grass,∗Lophopyrum ponticum (Podp.) A.Love., is one of the most severe and widely distributed weeds of saline coastal wetlands in south-eastern Australia. It is promoted by the agricultural extension arm of the Victorian government as a salt-tolerant pasture grass; however, its broad ecological amplitude and robust life form make it a most serious invader of upper saltmarsh in Victoria. We assessed the effectiveness of different control measures, including slashing and herbicides, for the management of∗L. ponticum infestations (and their side effects on saltmarsh communities) in the Western Port region of Victoria. A nominally monocot-specific herbicide widely used to control∗Spartina, Fluazifop-P, was ineffective in controlling∗L. ponticum. The broad-spectrum systemic herbicide glyphosate was more effective in controlling∗L. ponticum, but had undesirable impacts on native plant species. Controlling weeds in coastal wetlands using available herbicides for use near coastal waterways would seem to remain problematic. Source

Cinque K.,Melbourne Water | Jayasuriya N.,RMIT University
Journal of Water and Health | Year: 2010

To ensure the protection of drinking water an understanding of the catchment processes which can affect water quality is important as it enables targeted catchment management actions to be implemented. In this study factor analysis (FA) and comparing event mean concentrations (EMCs) with baseline values were techniques used to asses the relationships between water quality parameters and linking those parameters to processes within an agricultural drinking water catchment. FA found that 55% of the variance in the water quality data could be explained by the first factor, which was dominated by parameters usually associated with erosion. Inclusion of pathogenic indicators in an additional FA showed that Enterococcus and Clostridium perfringens (C. perfringens) were also related to the erosion factor. Analysis of the EMCs found that most parameters were significantly higher during periods of rainfall runoff. This study shows that the most dominant processes in an agricultural catchment are surface runoff and erosion. It also shows that it is these processes which mobilise pathogenic indicators and are therefore most likely to influence the transport of pathogens. Catchment management efforts need to focus on reducing the effect of these processes on water quality. © IWA Publishing 2010. Source

Rajeev P.,Monash University | Kodikara J.,Monash University | Chiu W.K.,Monash University | Kuen T.,Melbourne Water
Key Engineering Materials | Year: 2013

Health monitoring of civil infrastructure systems has recently emerged as a powerful tool for condition assessment of infrastructure performance. With the widespread use of modern telecommunication technologies, structures could be monitored periodically from a central station located several kilometres away from the field. This remote capability allows immediate damage detection, so that necessary actions are taken to reduce the risk. Optical fiber sensors offer a relatively new technology for monitoring the performance of spatially distributed structures such as pipelines. In this regards, several commercially available strain and temperature sensing equipment such as discrete FBGs (Fibre Bragg Gratings) and fully distributed sensing techniques such as Raman DTS (distributed temperature sensor) and Brillouin Optical Time Domain Reflectometry (BOTDR) typically offer sensing lengths of the order of 100 km's. Distributed fiber optic sensing offers the ability to measure temperatures and/or strains at thousands of points along a single fiber. In this paper, the authors will give a brief overview of these optical fiber technologies, outline potential applications of these technologies for geotechnical engineering applications and experience in utilising BOTDR in water pipeline monitoring application. © (2013) Trans Tech Publications, Switzerland. Source

Forsyth D.M.,Arthur Rylah Institute for Environmental Research | Woodford L.,Arthur Rylah Institute for Environmental Research | Moloney P.D.,Arthur Rylah Institute for Environmental Research | Hampton J.O.,Ecotone Wildlife Veterinary Services | And 2 more authors.
PLoS ONE | Year: 2014

There is much interest in understanding how anthropogenic food resources subsidise carnivore populations. Carcasses of hunter-shot ungulates are a potentially substantial food source for mammalian carnivores. The sambar deer (Rusa unicolor) is a large (≥150 kg) exotic ungulate that can be hunted throughout the year in south-eastern Australia, and hunters are not required to remove or bury carcasses. We investigated how wild dogs/dingoes and their hybrids (Canis lupus familiaris/dingo), red foxes (Vulpes vulpes) and feral cats (Felis catus) utilised sambar deer carcasses during the peak hunting seasons (i.e. winter and spring). We placed carcasses at 1-km intervals along each of six transects that extended 4-km into forest from farm boundaries. Visits to carcasses were monitored using camera traps, and the rate of change in edible biomass estimated at ∼14-day intervals. Wild dogs and foxes fed on 70% and 60% of 30 carcasses, respectively, but feral cats seldom (10%) fed on carcasses. Spatial and temporal patterns of visits to carcasses were consistent with the hypothesis that foxes avoid wild dogs. Wild dog activity peaked at carcasses 2 and 3 km from farms, a likely legacy of wild dog control, whereas fox activity peaked at carcasses 0 and 4 km from farms. Wild dog activity peaked at dawn and dusk, whereas nearly all fox activity occurred after dusk and before dawn. Neither wild dogs nor foxes remained at carcasses for long periods and the amount of feeding activity by either species was a less important predictor of the loss of edible biomass than season. Reasons for the low impacts of wild dogs and foxes on sambar deer carcass biomass include the spatially and temporally unpredictable distribution of carcasses in the landscape, the rapid rate of edible biomass decomposition in warm periods, low wild dog densities and the availability of alternative food resources. © 2014 Forsyth et al. Source

Greet J.,University of Melbourne | Rees P.,Melbourne Water
Ecological Management and Restoration | Year: 2015

Phragmites or Common Reed (Phragmites australis) is a natural component of many wetlands but can be highly invasive. Phragmites is encroaching into important mudflat habitat areas of the Ramsar-listed Seaford Wetlands (Melbourne, Victoria), which are critical for migratory birds. We assessed the efficacy of slashing as a means of controlling Phragmites by establishing twelve 5 m × 5 m quadrats within mature Phragmites reed beds and slashing half of them. The response of Phragmites to slashing was highly variable and dependent on the elevation (i.e. subsequent flooding) of the slashed quadrats. Phragmites regrowth was minimal in lower-lying quadrats which were wholly inundated for several months each of the following two years (to a mean depth of ~22 cm). In contrast, in quadrats of higher elevation, which were mostly only partially or shallowly inundated, Phragmites recovered almost completely within 10 months. In quadrats that were not slashed there was no change in Phragmites cover (i.e. it remained ~100%) irrespective of flooding extent. It is suspected that prolonged flooding above the height of the remaining stubble is necessary to prevent recovery. Thus, slashing may be a successful means of controlling Phragmites when low-lying areas are targeted and these are subsequently flooded to a sufficient depth (e.g. >20 cm) for at least several months. © 2015 Ecological Society of Australia. Source

Discover hidden collaborations