Brooks A.J.,New South Wales Office of Water |
Chessman B.C.,Climate Change and Water |
Haeusler T.,New South Wales Office of Water
Journal of the North American Benthological Society | Year: 2011
The biological effect of water abstraction from unregulated streams in New South Wales, Australia, was assessed with data on macroinvertebrate assemblages in riffles (445 samples) and pool edges (718 samples) obtained from a national assessment of river condition in 1995 to 2000. We used limiting environmental difference (LED) modeling to predict the macroinvertebrate assemblage expected for each sample in the absence of water abstraction and estimated effect by comparing predicted and observed assemblages for sites with upstream abstraction. We found a high likelihood of effect on macroinvertebrates in 30% of riffles with upstream abstraction and 22% of edges. Complex combinations of biological traits appeared to determine the sensitivities and tolerances of individual taxa to water abstraction. For example, rheophilous families generally were rarer than predicted in apparently affected riffles, where thermophilic families seemed tolerant of the effects of water abstraction, and free-swimming families were less common than predicted in apparently affected edges, where families with tegument respiration appeared unaffected by water withdrawals. The trait response was clearer for the riffle fauna than for the edge fauna, perhaps because the physical and chemical effects of abstraction are more consistent for riffles than for edges. Our approach can support management planning by identifying taxa that are most at risk from water abstraction and sites where apparent effects are most evident. © 2011 The North American Benthological Society.
Chessman B.C.,Climate Change and Water |
Townsend S.A.,Charles Darwin University
Ecological Indicators | Year: 2010
The DSIAR biotic index for freshwater diatoms, regarded as a potential indicator of impact from agricultural and urban land use on rivers in temperate south-eastern Australia, did not correlate significantly with an index of catchment condition in a tropical region of northern Australia. However, the relationships between the index and water chemistry, especially pH, salinity and concentrations of nitrogen and phosphorus, were consistent in both regions. The variable relationship between the index and catchment conditions can be explained by differing effects of catchment land use on stream-water chemistry in northern and southern Australia. In the south, land use has commonly resulted in increases in stream pH, salinity and nutrients, whereas in the north its impact on pH and salinity appears weak. These findings emphasise the need to interpret biological and ecological indices in the context of the varying causal pathways by which human activities affect stream ecosystems in different circumstances. © 2009 Elsevier Ltd. All rights reserved.
Lunney D.,Climate Change and Water |
Lunney D.,Murdoch University
Australian Zoologist | Year: 2010
This paper traces the post World War Il debate over kangaroo management, and how the various parties have managed the issue to arrive at the current levels of kangaroo harvest, with particular reference to NSW and die transition of policy from culling kangaroos as an agricultural pest to a commercial harvest as the principal driver. Kangaroos have been variously represented in the debate as pests, a commercial resource, an Iconic Australian symbol, and endangered species. In 1958, kangaroos narrowly survived a pastoralists' vote to list them as noxious animals. If it had passed, and been agreed upon by State Cabinet, it would have made it compulsory for landowners to rid their land of these animals because they would then have been noxious species. Over 1964 and 1965, culled kangaroo populations crashed during drought It showed that for kangaroo management to be effective In the long-term the original tenet in the Fauna Protection Act 1948 of kangaroos as pests had to be re-interpreted and, in Allen Strom's words: "kangaroos needed to be managed on a sustained yield basis." Fifty years later the debate is better informed, with a sustainable population management approach, which Includes commercial harvesting. In a statement on the subject In 1983, Neil Shepherd provided the certainty as to what was underpinning the kangaroo management program at that time:"Commercial harvesting Is sanctioned by wildlife authorities to reduce the impact of kangaroos on agriculture. Management for conservation is die primary objective and the harvest industry has no right to exist independent of the conservation program." He also concluded that farming kangaroos was not feasible, and pointed out that they have never been intensively farmed. What was needed by the late 1980s was an effective advocate who could put the material together into a persuasive argument to move the public sentiment from pest management to sustained yield. If it had been attempted 10-20 years earlier, Shepherd observed, it would have been unsuccessful because the science to support the proposition, the research driven by Graeme Caughley from die mid 1970s to 1987, had not been undertaken. An advocate of a change in policy was Gordon Grigg. His proposal, first published in 1987, was to substitute kangaroo harvesting for sheep farming on the sheep rangelands as an answer to both widespread land degradation and sustainable kangaroo management Grigg later gave it the epigrammatic description of "sheep replacement therapy".The modern debate now centres on matters of ethics and animal welfare on the one hand, and conservation management policies on the other.A report in 1998 into the Commercial Utilisation of Australia Native Wild life concluded "that it is a legitimate activity of the Federal Government to support an export industry based on the commercial harvesting of kangaroos, which is being prejudiced overseas by public campaigns based on false information. "Peter Singer, in 2005, took the view that "Those who see kangaroos only as a resource, overlook the ethical aspects of how we are treating other sentient beings. "In their 2006 review of the NSW Kangaroo Management Program, Olsen and Low concluded that shooting remains the most economical, humane and cost-effective way to cull/harvest kangaroos; rainfall is the overriding driver of population density and that die current harvest strategy (15-17%) appears to be achieving its current twin goals of sustainable use of natural resources and die maintenance of viable populations of the four harvested species. Thus the debate continues. However, this history of the debate on the commercial harvesting of kangaroos has revealed that it has been long running, filled with strong arguments and strong players, and that science and policy have had a long struggle to assimilate the needs of the other.The 2007-2011 NSW kangaroo management plan is tided New South Wales Commercial Kangaroo Harvest Management Plan. This bold tide acknowledges the change in management oudook from damage mitigation to sustainable use. The historical record also demonstrates that the current NSW management plan, which is underpinned by an objective to manage a sustainable kangaroo harvest is the outcome of a long and public debate.
Geering D.J.,Climate Change and Water
Corella | Year: 2010
The Regent Honeyeater has been the subject of intensive study and conservation effort over the past decade and a half. Until now, there has been no guide to accurately age and sex Regent Honeyeaters in the field. Being able to age and sex birds potentially provides data on population structure and dynamics. In particular, it can provide a measure of the recruitment of juveniles into the breeding population. Regent Honeyeaters can be confidently allocated to age classes of J, 1, 2- or 2+ based on plumage and soft part characters and sexed based on wing length and head-bill measurements.
Clarke H.G.,Climate Change and Water |
Clarke H.G.,University of Sydney |
Smith P.L.,Climate Change and Water |
Pitman A.J.,University of Sydney
International Journal of Wildland Fire | Year: 2011
Skill-selected global climate models were used to explore the effect of future climate change on regional bushfire weather in eastern Australia. Daily Forest Fire Danger Index (FFDI) was calculated in four regions of differing rainfall seasonality for the 20th century, 2050 and 2100 using the A2 scenario from the Special Report on Emissions Scenarios. Projected changes in FFDI vary along a latitudinal gradient. In summer rainfall-dominated tropical north-east Australia, mean and extreme FFDI are projected to decrease or remain close to 20th century levels. In the uniform and winter rainfall regions, which occupy south-east continental Australia, FFDI is projected to increase strongly by 2100. Projections fall between these two extremes for the summer rainfall region, which lies between the uniform and summer tropical rainfall zones. Based on these changes in fire weather, the fire season is projected to start earlier in the uniform and winter rainfall regions, potentially leading to a longer overall fire season. © 2011 IAWF.
Eldridge D.J.,University of New South Wales |
Val J.,Climate Change and Water |
James A.I.,University of New South Wales
Austral Ecology | Year: 2011
Despite the widespread recognition that disturbance by livestock affects multiple indices of landscape health, few studies have examined their effects on both biotic and abiotic processes. We examined the effects of livestock disturbance on soil, vascular plants and reptiles across a disturbance gradient in a semi-arid Australian woodland. Our gradient ranged from long-ungrazed water remote sites, through intermediately grazed recovering sites, to currently grazed sites close to water. Our aim was to examine the nature of the effects of grazing-induced disturbance on biotic and abiotic processes along the gradient. We detected small biotic effects, but no abiotic effects, at low levels of disturbance (intermediate sites). We could not detect a consistent biotic effect on plants or reptiles along the gradient, except between the extreme disturbances. In contrast, we recorded substantial reductions in abiotic structure and function at the most disturbed sites. Structural changes included reductions in the cover of shrub hummocks and increases in bare soil, and reductions in cryptogamic soil crusts. Structural changes were associated with declines in function (soil stability and nutrient indices). Our data are consistent with the notion that abiotic effects predominate at high levels of disturbance in rangelands. Given the extent of abiotic modification at currently grazed sites, the cover of abiotic elements such as hummocks and soil surfaces would seem a better indicator of the long-term effect of grazing-induced disturbance than biotic components. The extent of disturbance at currently grazed sites across large areas of rangeland suggests that autogenic recovery will be protracted. © 2010 The Authors. Journal compilation © 2010 Ecological Society of Australia.
Bowker M.A.,Northern Arizona University |
Eldridge D.J.,University of New South Wales |
Val J.,Climate Change and Water |
Soliveres S.,Rey Juan Carlos University
Soil Biology and Biochemistry | Year: 2013
Water redistribution has a profound influence on dryland ecosystem function. This hydrological function is largely regulated by ecosystem engineers including biological soil crusts (biocrusts) which produce run-off, and burrowing animals, such as the greater bilby, whose pits capture water. We estimated the relative importance of these two ecosystem engineers in determining infiltration rates in a system where dune slopes shed water to adjacent interdune swales to maximize overall productivity. Also, we determined which biocrust property was most hydrologically important: total cover, composition, patch aggregation or spatial heterogeneity. While both biocrusts and burrowing animals equally affected the overall infiltration through macro- and micropores (under ponding), only biocrusts were important for the infiltration specifically via micropores (under tension). Of the studied biocrust properties, community composition was the strongest influence such that the greater the prevalence of early successional biocrust patches, the greater the infiltration rate. Greater total cover of biocrusts reduced infiltration, and the spatial properties were relatively unimportant. Although bilbies and biocrusts comparably influenced infiltration under ponding at the microscale, realistic cover of bilby pits at the landscape scale is unlikely to strongly impair the hydrological function of dunes. Reintroduction of the endangered bilby may enhance nutrient cycling and plant recruitment via its seed and resource capturing pits, without a concomitant disruption of hydrological function. In contrast, removal of biocrusts caused by, e.g., livestock trampling, is expected to strongly enhance infiltration in the run-off areas, strongly reducing ecosystem productivity at the landscape scale. © 2013 Elsevier Ltd.
Shao Y.,University of Cologne |
Ishizuka M.,Kagawa University |
Mikami M.,Japan Meteorological Research Institute |
Leys J.F.,Climate Change and Water
Journal of Geophysical Research: Atmospheres | Year: 2011
A critical problem in dust research is to estimate size-resolved dust emission rates. Several dust schemes have been proposed but are yet to be rigorously tested against observed data. In the recent Japan-Australia Dust Experiment (JADE), size-resolved dust fluxes were measured. In this study, the JADE data are used to test a size-resolved dust scheme. Our aim is to examine whether the scheme has the capability to predict size-resolved dust fluxes, what the ranges of the scheme parameters are, and whether the scheme is sensitive to the parameters. The JADE data show that dust emission depends linearly on saltation flux and thus confirm the basic assumption of the scheme. The magnitudes of the scheme parameters are found to be consistent with those reported in earlier studies. The estimated size-resolved dust fluxes are in satisfactory agreement with the measurements, although considerable discrepancies remain and are difficult to rectify without speculative tuning of the scheme input parameters. The discrepancies have been traced back to the uncertainties in the parent soil particle size analyses and in the dust flux observations. Ensemble tests showed both model physics uncertainties and parameter uncertainties. It is proposed that the dust scheme under consideration is not as sensitive as previously suspected and is likely to perform well if the parameters are specified within a reasonably correct range. Copyright 2011 by the American Geophysical Union.
Malcolm H.A.,Solitary Islands Marine Park |
Malcolm H.A.,University of New England of Australia |
Davies P.L.,Sydney Water |
Jordan A.,Climate Change and Water |
Smith S.D.A.,University of New England of Australia
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2011
Improved understanding of the East Australian Current (EAC) and sea-temperature patterns within the Solitary Islands region of northern New South Wales, an area where tropical and temperate faunas overlap, is an essential step in explaining cross-shelf gradients in biotic patterns. Sea temperature at ~10. m was logged using thermistors at seven stations every 30. minutes between January 2001 and December 2008. Stations were replicated in three distance-from-shore categories (<1.5; 1.5 to 6; and >6. km from the coast), corresponding with predominant assemblage patterns of reef fish. Daily, monthly, seasonal and yearly sea-temperature patterns were compared between and within stations and distance-from-shore categories. SST images were examined to determine the role of the EAC in producing short-period (2 to 4 days) temperature anomalies. Sea temperatures ranged between 16.6-27.5. °C and were highest offshore and lowest inshore. Offshore sites experienced average temperatures ~1. °C higher than nearshore sites over the 8-year study. There was considerable variation in sea temperature between years, with 2002 and 2006 being the warmest and 2007 the coolest. These patterns correspond with strong inter-annual variability of the EAC at the scale of the Solitary Islands region. The EAC influenced shelf waters most strongly during late spring/summer when temperatures were also most variable over the smallest temporal scales (hours, days). Short-period anomalies between and within stations could largely be explained by variable encroachment of the EAC across the shelf and/or colder intrusions of water forming adjacent to the coastline. Previous assumptions that the EAC strongly influences gradients in the distribution of tropical species in this nearshore region are strongly supported. © 2010 Elsevier Ltd.
Ferrier S.,Climate Change and Water |
Drielsma M.,Climate Change and Water
Diversity and Distributions | Year: 2010
Aim: To describe a general modelling framework for integrating multiple pattern- and process-related factors into biodiversity conservation assessments across whole landscapes. Location: New South Wales (Australia), and world-wide. Methods: The framework allows for a rich array of alternatives to the target-based model traditionally underpinning systematic conservation planning and consists of three broad modelling components. The first component models the future state (condition) of habitat across a landscape as a function of present state, current and projected pressures acting on this state, and any proposed, or implemented, management interventions. The second component uses this spatially explicit prediction of future habitat state to model the level of persistence expected for each of a set of surrogate biodiversity entities. The third component then integrates these individual expectations to estimate the overall level of persistence expected for biodiversity as a whole. Results: Options are explored for tailoring implementation of the framework to suit planning processes varying markedly in purpose, and in availability of data, time, funding and expertise. The framework allows considerable flexibility in the nature of employed biodiversity surrogates (species-level, discrete or continuous community-level) and spatial data structures (polygonal planning units, or fine-scaled raster), the level of sophistication with which each of the three modelling components is implemented (from simple target-based assessment to complex process-based modelling approaches), and the forms of higher-level analysis supported (e.g. optimal plan development, priority mapping, interactive scenario evaluation). Main conclusions: The described framework provides a logical, and highly flexible, foundation for integrating disparate pattern- and process-related factors into conservation assessments in dynamic, multiple-use landscapes. © 2010 Blackwell Publishing Ltd.