bluuebunny/crossref_metadata_2025 huggingface dataset:
Using the Aboriginal Rangelands: 'insider' Realities and 'outsider' Perceptions.
Authors: Young E , Ross H
Published: December 2005

Aboriginal ownership of Australia's rangelands is already significant and is likely to increase with recognition of Native Title. Aboriginal management of the rangelands, including their use for cultural and subsistence purposes as well as for pastoralism and conservation (parks) presents alternatives to conventional practices. Traditional ecological knowledge is applied in all forms of Aboriginal land use. Multiple use of the land, combining two or more forms of use within a single area, is predominant. Such strategies are particularly important in more marginal parts of the rangelands where, because of environmental unpredictability, single purpose use may threaten the successful survival of landholders. A case-study of contemporary land use practised by the Ngarrinyin people in one such marginal area, the interior section of the Kimberley's remote Gibb River road, illustrates these points. As it shows, Aboriginal groups have varied their land management responses according to the extent of their ownership and control over their traditional country. The multiple uses which they practise enhance both their chances of providing a livelihood and the sustainability of the land as a whole. Non-Aboriginal neighbours have also increasingly moved towards multiple use strategies. These realities challenge the common perception from the 'outsider' government authorities that such regions should focus on single purpose use, with pastoralism the prime emphasis. The paper argues that this challenge must be met, by revision of land tenure to accommodate multiple use, by improving Aboriginal and non-Aboriginal communication and information exchange on rangeland management, by providing appropriate land management programs and by engaging in longterm, holistic planning for all residents of such regions. Such approaches would enhance opportunities for closing the gap between the realities of rangeland use and beliefs in appropriate forms of use.
Ground-Based Monitoring: a Process of Learning by Doing.
Authors: Burnside DG , Chamala S
Published: December 2005

Rangeland monitoring using ground-based methods has been presented as a major instrument in the management of rangelands. Yet there are some doubts about its utility as a stand-alone tool in providing reliable, objective evidence on range trend. If the technology is to have relevance in rangeland management at the landholder level, stronger recognition and direction is required for other, potentially important roles, that contribute to the development of knowledge applied to management. This position recognises landholders' primary responsibility for day-to-day decisions in rangeland management. Decision-making, adult learning, action-research and ecosystem management principles are drawn on to propose and advocate two separate but complementary roles for ground-based monitoring. Firstly, in a learning role, landholders' capture and use of ground-based monitoring data can develop and enhance the managerial knowledge and skill applied to their decisions. Secondly, in a decision supporting role, there is the interpretation of range trend from ground-based range monitoring data and the incorporation of that information into management decisions at tactical and strategic levels. Using a collaborative approach to system development and support, this blend of 'soft' and 'hard' technologies can combine in a process of 'learning by doing' that will enhance the quality of management applied in the rangelands.
The Prime Minister's Pre-Election Promise of World Heritage Listing for the Lake Eyre Basin: Flight or Flight of Fancy?
Authors: Reid J
Published: December 2005

In March 1993 the Australian Prime Minister promised World Heritage listing of diverse wetlands in the South Australian Lake Eyre region. Recent developmental pressures within the region and in the catchment interstate led the environment movement to intensify the pro-listing campaign. Current theory on ecological functioning of arid Australia and unregulated rivers, and a rapid expansion of knowledge about the region's heritage, support the technical legitimacy of heritage significance and highlight the value of integrated regional planning and management structures as have been developed in the Murray- Darling Basin. The Lake Eyre Basin covers one sixth of Australia, and World Heritage proposals for even a small area have alarmed commercial interests and state governments, due to the implications of federal intervention and changes in existing management that could follow. This alliance has mounted an aggressive and effective media campaign and lobbied federally to stall any progress with the Commonwealth's continuing commitment to World Heritage assessment. As with other recent conflicts concerning specific areas of land, resources and established commercial interests, this dispute has become highly divisive leading to a stalemate. The two campaigns and the roles of government and media are analysed to show that the pastoral industry, some mining interests and the states will tend to remain opposed to World Heritage proposals over moderate to large areas in the rangelands. Broad (rhetorical) initiatives such as national strategies, policies and conceptual management models are less threatening and can be broadly embraced (and ignored). Lessons from the mining industry and socio-economic case studies are instructive.
Land Administration in the Rangelands: What for, Who for and How?
Authors: Wilcox DG , Burnside DG
Published: December 2005

The path of change in land administration practices from that which had the exploitation of pastoral resources by domestic stock as its principal objective to a position where administration is required to take a more holistic view of the management of rangelands for a wide range of uses is discussed in this paper. Although historically administration has been generally slow to react to changing operating environments, a varying degree of legislative and behavioural changes have occurred in response to a wide range of influences. These influences include: objective information on rangeland resources; complementary legislation affecting the use of these resources; new Government programs directed at improving land management; a developing awareness of the value of rangeland for purposes other than grazing domestic animals; and the economic difficulties facing the grazing industries. With major changes and uncertainties surrounding rangeland use, we suggest that administrators themselves must define their objectives clearly in terms of the needs of all land users, within a framework of sustainable land use. This work can best be done within new networks and partnerships involving the relevant agencies and groups. By defining acceptable criteria and decision rules within these structures, administrators can focus more on the quality of the process in land administration and measuring their performance, rather than regulating for their defined desirable outcome. Finally, we recognise that the evaluation of administrative performance is an area that requires urgent attention.
Changes in Grass Density in Australian Semi-Arid Woodlands.
Authors: Grice AC , Barchia I
Published: December 2005

Changed grazing regimes since European settlement have been widely proposed as the cause of a decline of indigenous perennial grasses in the semi-arid woodlands of eastern Australia. A five year experiment using exclosures examined the effects of grazing on densities of perennial grasses. Short- lived Stipa spp. and Aristida spp. were dominant at most sites. Their densities fluctuated greatly with season and reached over 200 plants/m2 during climatically favourable periods. The long-lived Eragrostis eriopoda occurred at densities that were generally less than 5 plants/m2 and its populations were relatively stable. The response of Enneapogon avenaceus was distinctive. Though its density fluctuated considerably, successive peaks in density were higher and the species increased more in ungrazed areas than in destocked or unfenced areas. The differences between grazed and ungrazed populations became greater with successive peaks in density. Within the short periods that pastoralists are likely to be willing or able to apply such treatments, destocking or even removing all herbivores is unlikely to have a large effect on the density of many palatable perennial grass species. The rate of response to resting pastures will depend on seasonal conditions.
Natural Regeneration of Ground Storey Vegetation in a Semi-Arid Woodland Following Mechanical Disturbance and Burning. 1. Ground Cover Levels and Composition.
Authors: Walker PJ , Koen TB
Published: December 2005

A study was made over a period of 12 years of the natural regeneration of vegetation along a corridor corridor cleared for the construction of a natural gas pipeline in a semi-arid woodland in central- western New South Wales. Total cover, proportion of grasses, and species composition were assessed on the infilled trench and on areas from which topsoil had been bladed, as well as on adjacent undisturbed areas and areas burned by a wildfire. All areas were grazed continuously by sheep under normal station management, and by native animals. After four years of about average rainfall, total cover on disturbed areas had regained levels as high or higher than on adjacent areas, and was maintained thereafter. On many individual sites this period was as short as eighteen months. The proportion of grasses remained much lower on disturbed areas, except for some periods of annual grass dominance. Species composition remained very different between disturbed and undisturbed areas, the main difference being in perennial species. However, composition also varied markedly between years, according to rainfall seasonality and competition from previously established plants. Little difference was apparent between undisturbed areas and similar areas which had burned twelve months before the first measurements. Mechanical disturbance caused by trenching and blading had a much greater effect on vegetation than did fire, and the effects were still obvious after twelve years.
Assessing Options for Farming Systems Transitions in New Zealand's Mountainlands.
Authors: Foran B , Allan B
Published: December 2005

The transition of an agricultural ecosystem from a less to a more sustainable or desirable state is dependent as much on the routes and tactics used to effect the transition, as it is on the management ideas and the biological components used. Against the background of the failure of farmers to take up an integrated "all grass wintering system" in the mountain lands of the South Island of New Zealand, we compared a wide range of transitional opportunities and evaluated them in economic terms over a 20 year period.

Farm structure at the start of the transition was a rather obvious but key criterion for success of the transition. Transition from a farm structure where supplementary feeding cost NZ$90,000 per year into the new system, allowed a position better than the "do nothing" option to be achieved in as little as 8 to 9 years. Transitions from smaller farm structures of $60,000 and $30,000 took from 12 to more than 20 years to achieve a cash position better than the "do nothing" option. Herein lies the quandary for all farming systems which might aim to make transitions and to "do it better".

We explore the sensitivity of these general results to the effects of product price and interest rates, wool growth and lambing rates, whether transition should be gradual or fast, and the incumbent debt levels that can be serviced in addition to the new development. In conclusion we note some essential components of any study of transition of pastoral systems. It is important that dynamic tools are used in any transition study since the route taken in the transition can be more important than the end point.

The economic advantage offered by new pastoral technology is important, particularly the time it takes to become fully implemented. Sensitivity analyses should be undertaken for key production and price assumptions. It is helpful to present these analyses as three-dimensional diagrams to allow biological and economic risk to be assessed against each other. While increased animal numbers bring better economic returns, both industry attitudes and the management of ecological risk may require the maintenance of present animal numbers. Increased profitability will then rely on individual animal performance, and higher quality livestock products.
The Population Dynamics of Perennial Shrubs in a Western Australian Chenopod Shrubland in Relation to Grazing and Seasonal Conditions.
Authors: Yan ZG , Holm AM , Mitchell AA
Published: December 2005

This paper examines the responses of a chenopod community in arid Western Australia to various grazing treatments over an eight-year period. The population dynamics of the major perennial species are analysed in relation to grazing treatments and seasonal conditions. Continuous grazing and spelling had no discernible impact on community composition when compared with the nil- grazing treatment. However, continuous grazing increased population turn-over rate, which reflected a higher level of recruitment and mortality, when compared with the nil-grazing treatment. In general, populations of all major perennial species remained stable or increased during the study period. Both mortality and recruitment were sporadic, corresponding to the erratic rainfall events during the trial period. For the three major perennial species, Maireana georgei, M. pyramidata, and Ptilotus beardii, linear regression analyses reveal that 38-74% of the variation in mortality and recruitment was caused by seasonal conditions.
An Integrated Approach for Maximising Local and Scientific Knowledge for Land Management Decision-Making in the New Zealand High Country.
Authors: Bosch OJH , Allen WJ , Williams JM , Ensor AH
Published: December 2005

This paper describes the development of a process to facilitate the identification and introduction of
sustainable land management practices in the high country of New Zealand. The process was designed
to gather and structure community knowledge (both local and scientific) into a single, accessible
decision support system (DSS). The development and provision of appropriate, and user-friendly
monitoring tools is supported. An outline is given of how this integrated system can be used to
integrate monitoring with adaptive management. Special reference is made to how this process is
used as a large-scale ecological 'experiment', to enhance continually the knowledge base available
for land use decision-making in the South Island high country of New Zealand.
Run-Off and Soil Movement on Mid-Slopes in North-East Queensland [Australia] Grazed Woodlands.
Authors: Scanlan JC , Pressland AJ , Myles DJ
Published: December 2005

Run-off, bedload and sediment concentration data were collected over a five-year period from unbounded catchments in grazed and exclosed pastures in woodlands. Cover varied from 4% during drought conditions to almost 100% in exclosed areas after above-average rainfall. High bedload soil loss, sediment concentration and run-off percentages were associated with low cover (<30%).

Run-off as a percentage of rainfall increased linearly with rainfall intensity; decreased linearly with cover; decreased slightly as soil moisture status declined; and reached a maximum at intermediate rainfall events. Interactions between these factors were observed. Run-off was up to 30% of rainfall in moderate rainfall events (30-40 mm) where maximum rainfall intensity over any 15 minute period (I15) exceeded 70 mm/h. When soil moisture status was high, mean run-off exceeded 30% for 40-80 mm rainfall events. For all rainfall event sizes, run-off exceeded 20% where I15 exceeded 60 mm/h. Cover had very little effect on run-off when rainfall intensity was low (I15<20 mm/h), soil water deficit was low (<10 mm) or when rainfall events were >75 mm or <10 mm.

Bedload plus suspended sediment loads ranged from negligible to 1000 kg/ha/a, depending principally on cover. Soil movement from areas with >40-50% cover was very low. Pastures dominated by Bothriochloa pertusa (a stoloniferous, naturalised grass) had lower run-off and lower rates of soil movement than pastures dominated by Heteropogon contortus (a native tussocky perennial grass) when compared at the same level of cover. Differences between grazed and exclosed areas could be attributed solely to differences in cover.
Objective `Safe' Grazing Capacities for South-West Queensland Australia: Development of a Model for Individual Properties.
Authors: Johnston PW , Mckeon GM , Day KA
Published: December 2005

Few tools are available to assist graziers, land administrators and financiers in making objective grazing capacity decisions on Australian rangelands, despite existing knowledge regarding stocking rate theory and the impact of stocking rates on land condition. To address this issue a model for objectively estimating 'safe' grazing capacities on individual grazing properties in south-west Queensland was developed. The method is based on 'safe' levels of utilisation (15%-20%) by domestic livestock of average annual forage grown for each land system on a property. Average annual forage grown (kglha) was calculated as the product of the rainfall use efficiency (kglhdmm) and average annual rainfall (mm) for a land system. This estimate included the impact of tree and shrub cover on forage production. The 'safe' levels of forage utilisation for south- west Queensland pastures were derived from the combined experience of (1) re-analysis of the results of grazing trials, (2) reaching a consensus on local knowledge and (3) examination of existing grazing practice on 'benchmark' grazing properties. We recognise the problems in defining, determining and using grazing capacity values, but consider that the model offers decision makers a tool that can be used to assess the grazing capacity of individual properties.
Perennial Grass Response to Seasonal Rests in Naturalised Pastures of Central New South Wales.
Authors: Dowling PM , Kemp DR , Michalk DL , Klein TA , Millar GD
Published: December 2005

The influence of grazing management, herbicide and fertiliser on botanical change in two perennial grass based pastures was assessed over six years at two sites in central New South Wales. Ten treatments at both sites compared continuous grazing, three seasonal rests from grazing (autumn, winter, summer), and herbicide application for seedling grass control, each at two levels of fertiliser addition (nil, recommended). These treatments were designed to screen options for management rather than devise complete systems. In a degraded perennial pasture dominated by annual grasses, the proportion of perennial grasses and forbs increased with summer rests, especially at the recommended fertiliser level. Legumes increased with herbicide application, and annual grasses remained high in the continuously grazed control and other treatments. There were no significant effects on composition from autumn or winter rests. On the summer rest treatment at the recommended fertiliser level, perennial grasses (mostly cocksfoot) increased from 11% to 30% compared with the control where perennial grass declined below 5%. The increase was due to both recruitment and increase in size of existing plants, as a consequence of resting the perennial grasses when actively growing, flowering and setting seed, in favourable seasons. In contrast, on the better quality perennial pasture dominated by phalaris, there were limited management effects and perennial grasses increased on all treatments over time. The absence of a response at this site was attributed to a lenient stocking rate, dominant perennial grasses and limited rainfall during periods when active growth might be expected. Summer rests in this case also led to a small increase in forbs. The data suggest that perennial grasses can be encouraged with a conservative stocking policy that maintains the available feed-on-offer above 1 t DM/ha through seasons of active growth.
The Need for a New Approach to Grazing Management - Is Cell Grazing the Answer?
Authors: Earl JM , Jones CE
Published: December 2005

With any grazing method, the grazing pressure applied to an individual plant is a site, stock density and time dependent variable and the diet selection hierarchy of grazing animals is to the disadvantage of the most palatable and actively growing pasture components. The greater the differences in palatability and abundance among the components of a sward, and the lower the stock density, the greater the variation in the grazing pressure exerted. These effects are heightened when animals are set-stocked under adverse environmental conditions. This paper reports the comparative effects of cell grazing and continuous grazing on pasture composition on three properties on the Northern Tablelands of New South Wales. The basal diameters, relative frequency and contribution to dry weight of the most desirablelpalatable species at each site were found to remain constant or to increase under cell grazing, while declining significantly under continuous stocking. The converse was true for the least palatable components of the pasture, which declined significantly under cell grazing but changed little under continuous grazing. Percentage ground cover was significantly higher after two years of cell grazing than under continuous grazing. These changes in pasture composition may have long-term benefits with respect to erosion control, nutrient cycling, hydrological function and the stability of animal production at the cell grazed sites.
Diversity and Change in Australia's Rangeland Regions: Translating Resource Values Into Regional Benefits.
Authors: Holmes JH
Published: December 2005

Australia's rangelands are experiencing a radical re-evaluation of broadacre natural resources, with declining commodity values and enhanced amenity values. This is indicative of a transition from a productionist to a post-productionist era in rural resource use and related policy directions. While this transition offers new opportunities, it also presents formidable structural problems for our rangelands, most notably in the shift from market towards non-market values and in the geographical transfer of value. These challenges require new responses in strategic regional planning. Effective planning must recognise not only the structural problems endemic to the rangelands but also the highly differentiated regional potentials which are increasingly evident. A provisional regionalisation for strategic resource use planning is proposed, based upon resource orientation and obtained using a simple scaling of potentials for pastoralism, mining, tourism and Aboriginal resource use. Seven distinctive regional types are proposed, with the most powerful dimensions of differentiation being between commodity - versus amenity - orientation and also between accessibility/urbanisation (linked to closer settlement, mining and tourism) versus remoteness (associated with 'frontier' regions and Aboriginal homelands). A structured approach towards translating resource potential into regional benefits is outlined.
Sheep Faeces Under Shearing Sheds: a Documentary of Vegetation Change Using Stable Carbon Isotope Analysis.
Authors: Witt GB , Moll EJ , Beeton RJS
Published: December 2005

In this study we report on a new technique for reconstructing long-tgrm vegetation changes in the Australian rangelands. Sheep faeces, which accumulate annually beneath shearing sheds, provide an untapped and potentially continuous record of vegetation change at a property scale. From stable carbon isotope analysis, inferences about the available vegetation can be made. Our analysis revealed vegetation changes slnce the construction of two sheds, a period of approximately 40 years. Results indicated a significant reduction in the availability of C, grasses on Currawinya (south-west Queensland). However, for the same period there was no significant change in proportion of C, and C, species contributing to the diet of sheep on Talyealye (north-west New South Wales). Given the abundance, age and distribution of shearing sheds in the Australian rangelands, the potential exists to reconstruct a detailed picture of vegetation change at a national scale.
The Effect of Short-Term Exclosure of Watering Points on the Behaviour and Harvesting Efficiency of Grey and Red Kangaroos.
Authors: Hacker RB , Freudenberger D
Published: December 2005

The selective exclusion of kangaroos from water points installed for livestock may facilitate the control of the total grazing pressure by herbivores on pastoral leases. In observations at seven different study sites, we found that low lying electrified wires surrounding watering points (e.g. Finlayson troughs) are largely effective in selectively excluding red kangaroos and the two species of grey kangaroo from water. Some sheep will experience shocks when exposed to the wire, but no unmanageable effects were observed. However, the devices are considered unsuitable for use with cattle which quickly damage the installations Such devices produced significant local concentrations of kangaroos during two of the seven replications when pre-exclosure minimum temperatures were above 19260C and maxima above 3 1260C. Shooter experience indicated the potential exists to increase harvesting efficiency of kangaroos concentrated at electrically exclosed uaters, but we were unable to show this statistically. Key words: kangaroos, water exclosure, behaviour, harvesting efficiiency
Stocking Rate Impacts on the Production and Economic Performance of Steers Grazing Black Speargrass Pastures.
Authors: Macleod ND , Mcintyre S
Published: December 2005

A grazing trial conducted in subtropical Queensland examined the effect of four stocking rates (high, medium, low, very low) on beef production, economic returns and pasture stability. Liveweight gains of steers were recorded in legume sown pastures, over a five year period in which severe drought conditions prevailed. Although high stocking rates generated the highest levels of beef production per hectare, moderate rates generated the highest economic returns. The status of the dominant perennial tussock grass (Heteropogon contortus) was used as an indicator of pasture condition. While H, contortus declined in all treatments during the drought, populations were most persistent at the low stocking rate. The results provide clear evidence of a trade-off between ecologically optimal stocking rates and animal production. The highest net profit was derived from the medium stocking rate, which was more than 50% higher than the next most profitable stocking rate. However, at this stocking rate there was evidence of a decline in the dominant grass, H. contortus, which suggests that the medium stocking rate may not be sustainable over the long-term. The highest stocking rate paddocks all required supplementary feeding of stock and were poor both in economic return and ecological condition. The low stocking rate plots had the highest rates of liveweight gain per animal and had low ecological risk, but had low to negative returns on equity and were not sustainable economically. Key words: - stocking rates, black speargrass pastures, economics, range condition, drought.
A Quantitative Appraisal of Woody Shrub Encroachment in Western New South Wales.
Authors: Gardiner DB , Tupper GJ , Dundeon GS
Published: December 2005

Landsat Multispectral Scanner (MSS) digital imagery was used to estimate the distribution, density and change in woody shrub cover over time in western New South Wales. The purpose of the project was to derive maps of woody cover which can be used as a basis for regional planning and property planning. Assessment of woody vegetation cover using satellite imagery enables regions which are more susceptible to shrub encroachment to be targeted for control strategies. Dry season images which had minimal green vegetation were used, because the spectral signatures of scrubby ground cover interfered with the proper classification of woody vegetation. For each region, multidate imagery was classified using a pixel unmixing algorithm to derive data sets which showed woody canopy cover. These data were then rescaled to percentage values using aerial photography sampled throughout each region. A geographic information system (GIS) was used to derive changes in woody cover between both dates and to present the data in map form. Most current woody cover in the study area occurs at less than 20% cover, whilst higher levels (40 to 80%) occur in the eastern parts of the Louth and Barnato regions. At least 20,3 10 km2 of the 120,000 km2 study area is already affected by woody vegetation cover levels of greater than 40%, which significantly reduces carrying capacity and pastoral productivity. Changes in woody cover over a 10 to 20 year period were varied. Approximately 24% (26,041 km2) was relatively stable, whilst 20% of the Barnato region had moderate decreases (1 1 to 30%) due to wildfires, and increases of 11 to 30% cover occurred on 'hard red' soils in the east. Emerging woody vegetation of less than 10% cover occurred over 1816 km2 of Sandplains and Stony Lowlands in the Louth and Barnato regions, whilst woody vegetation levels of more than 40% cover occurred in the Barnato region. Considerable 'infilling' of previously unwooded areas was noted for regions which already had high levels of woody cover. A minimal amount of prescribed clearing was apparent from the change data, which suggests that effective control of shrubs is difficult to achieve and that future scenarios will see continued encroachment. The findings suggest that the southern Louth and Barnato regions are most at risk of further shrub encroachment, and that these areas need to be targeted for shrub control. The data provide a quantitative estimate of woody shrub cover which is useful for economic assessments, as well as providing an information base upon which woody shrub management strategies can be developed. Key words: Landsat Multispectral Scanner, remote sensing, geographic information system, change detection, rangeland, monitoring, land cover.
Implementing Satellite-Based Grazing Gradient Methods for Rangeland Assessment in South Australia.
Authors: Bastin GN , Tynan RW , Chewings VH
Published: December 2005

This paper reports on a project to adapt grazing gradient methods, which use satellite data, to assess the condition of the northern rangelands of South Australia. Within this region, cattle graze in large paddocks on mainly ephemeral vegetation that responds in often unpredictable ways to erratic rainfall. Two methods were tested: one calculates average cover levels at increasing distance from watering points while the other produces a map showing where vegetation response to rainfall is different to that which might be expected. Before using the methods, it was necessary to rapidly produce a map of landscape types reflecting grazing preference and we show how this was obtained from classified satellite data. It was not possible to derive an accurate index of vegetation cover from the satellite data for areas with a dark stone mantle and these areas were excluded from grazing gradient analyses. We describe how analysis software was adapted to the needs of a client (SA Department of Environment and Natural Resources) and how training was provided. Testing of the grazing gradient technology as a suitable method for determining lease condition in northern South Australia is continuing and is supported by both pastoralists in the region and the Pastoral Board. Key words: land condition, pastoral lease assessment, satellite data, thematic mapper, grazing gradients, technology transfer
Climate Change in Queensland's Grazing Lands: Ii. An Assessment of the Impact on Animal Production From Native Pastures.
Authors: Hall WB , Mckeon GM , Carter JO , Day KA , Howden SM , Scanlan JC , Johnston PW , Burrows WH
Published: December 2005

The 160 million ha of grazing land in Queensland support approximately 10 million beef equivalents (9.8 million cattle and 10.7 million sheep) with treed and cleared native pastures as the major forage source. The complexity of these biophysical systems and their interaction with pasture and stock management, economic and social forces limits our ability to easily calculate the impact of climate change scenarios. We report the application of a systems approach in simulating the flow of plant dry matter and utilisation of forage by animals. Our review of available models highlighted the lack of suitable mechanistic models and the potential role of simple empirical relationships of utilisation and animal production derived from climatic and soil indices. Plausible climate change scenarios were evaluated by using a factorial of rainfall (f 10%) * 3260C temperature increase * doubling CO, in sensitivity studies at property, regional and State scales. Simulation of beef cattle liveweight gain at three locations in the Queensland black speargrass zone showed that a *lo% change in rainfall was magnified to be a f 15% change in animal production (liveweight gain per ha) depending on location, temperature and CO, change. Models of 'safe' carrying capacity were developed from property data and expert opinion. Climate change impacts on 'safe' carrying capacity varied considerably across the State depending on whether moisture, temperature or nutrients were the limiting factors. Without the effect of doubling CO,, warmer temperatures and +lo% changes in rainfall resulted in -35 to +70% changes in 'safe' carrying capacity depending on location. With the effect of doubling CO, included, the changes in 'safe' carrying capacity ranged from -12 to +115% across scenarios and locations. When aggregated to a whole-of-State carrying capacity, the combined effects of warmer temperature, doubling CO, and +lo% changes in rainfall resulted in 'safe' carrying capacity changes of +3 to +45% depending on rainfall scenario and location. A major finding of the sensitivity study was the potential importance of doubling CO, in mitigating or amplifying the effects of warmer temperatures and changes in rainfall. Field studies on the impact of CO, are therefore a high research priority. Keywords: climate change, Queensland, simulation, rangelands, beef production, cattle, carrying capacity, CO,, utilisation
The Impact of Irrigation Withdrawals on Inland River Systems.
Authors: Thoms M , Cullen P
Published: December 2005

Responsible decision making about water extractions in arid and semi-arid areas requires a good understanding of both the physical and biological character of these systems. The intrinsic variability of these systems is an important ecosystem control. Ecological concepts and water management practices developed in temperate areas are inappropriate to these erratic and highly pulsed systems. Key words: Water resource development, environmental flows, environmental impact, management paradigms
Biodiversity implications of water management in the Great Artesian Basin.
Authors: Noble JC , Habermehl MA , James CD , Landsberg J , Langston AC , Morton SR
Published: December 2005

The Great Artesian Basin (GAB) underlies a vast, mainly arid, region where most of the indigenous biota are not dependent upon surface water. In contrast, an important minority is dependent on refuges such as mound springs and their associated wetlands. In some parts of the GAB, such as western New South Wales, many springs have either ceased to flow, or are now barely detectable, because the proliferation of artesian waterbores has reduced groundwater pressures. Because of the rarity of species endemic to mound springs, and the damage they have suffered since pastoral settlement, emphasis should be directed towards conservation and possible rejuvenation of these ecosystems. Provision of artificial sources of water allows more widespread grazing by livestock, larger native and feral herbivores, thereby posing threats to native plants and animals that do not use the water. Because of the proliferation of artificial waters and the grazing they allow, terrestrial grazing-sensitive species now appear to be confined to tiny patches in the landscape. Some nature reserves within the GAB retain numerous artificial sources of water. Most of these should be closed over time to reduce negative impacts on grazing-sensitive plants and animals, especially where these species are inadequately protected elsewhere. In those regions where the ratio of artificial to natural waters is still low, consideration should be given to balancing provision of water for livestock with conservation of biological diversity, by maintaining a patchwork of areas remote from water. In regions where the density of artificial waters is high, conservation of biodiversity on freehold and leasehold lands might be enhanced with a mix of approaches accommodating the needs of the biota and the aspirations of landholders, tailored according to land type and condition. Key words: Great Artesian Basin, biological diversity, mound springs, refuges, rare biota, grazing impact, conservation management, groundwater.
Native Grasslands of the Central Highlands, Queensland, Australia. Floristics, Regional Context and Conservation.
Authors: Fensham RJ
Published: December 2005

A floristic classification of grassland and related woodland vegetation from the Central Highlands of Queensland suggests four broad types: Mountain coolibah (Eucalyptus orgadophila) woodland on basalt, Mitchell grassland (dominated by Astrebla lappacea) on alluvia and two closely related groups dominated by Dichanthium sericeum, Blue grassland on basalt and Blue grassland on sediment. An analysis including floristic data from grassland and woodland on vertosols from throughout southern, central and western Queensland revealed that the Blue grasslands of the Central Highlands are highly dissimilar from other grasslands in Queensland. Mountain coolibah woodland on basalt is represented within four reserves, but the other more arable grassland types are either not represented or only barely represented within the reserve system. The most immediate threatening process to these communities is conversion to crops and this process is exacerbated by the difficulties of managing the grasslands as native pasture. Large areas of grasslands are degraded, having been converted from dominance by native perennial grasses to the unpalatable, annual, exotic herb Partheniunz hysterophorus. Once this shift has occurred a long period with little or no production benefits is required to recover a sward of native perennial grasses and the cropping alternative becomes particularly favourable. The long-term security of the native grasslands of the Central Highlands will require an enhanced reserve system and incentives designed to retain appropriately managed native pasture. Key words: grassland, grazing, reserves, woodland. Queensland, exotics, Parthenium
Influence of Landscape Structure on Kangaroo Abundance in a Disturbed Semi-Arid Woodland of Queensland.
Authors: Mcalpine CA , Grigg GC , Mott JJ , Sharma P
Published: December 2005

This paper develops a hierarchical landscape approach for investigating how landscape structure influences the abundance of eastern grey kangaroos, red kangaroos and common wallaroos on properties in a partially cleared semi-arid woodland of Queensland. This approach is applied to examine the extent to which a mosaic of spatial factors at a hierarchy of scales influences kangaroo abundance at the property level. the level of management interest. The analysis concludes that the structure of the property habitat mosaic, coupled with pasture productivity, is the most important influence for each species. Access to water was not a limiting factor. although it may be important locally. Grey kangaroos prefer an even mosaic of all habitat types on properties with productive grass-dominated pastures. Red kangaroos are positively associated with run-on areas and large-shrub regrowth patches. reflecting their foraging preferences for forbs and short grasses and their ability to use more open habitats. Wallaroos have a clumped density distribution associated with a heterogeneous mosaic of open habitats interspersed with fragmented forest patches and small to medium-grained shrub-regrowth patches. The research. \+bile not replicated. identifies linkages between tree clearing practices at the property level and increased large kangaroo abundance in the region, These linkages have been previously overlooked in thc kangaroo Inanagement debare. Therefore. any tree clearing guidelines dt.\eloped at the propert) level need to be sensitive to key ecological processes influencing kangaroo populations at both the landscape and property levels. If not, the sustainable management of total grazing pressure (livestock plus kangaroos) and biodiversity conservation will never become a reality. Key words: kangaroos, landscape structure, landscape change, pattern, process, scale
Declines in Vegetation Patches, Plant Diversity, and Grasshopper Diversity Near Cattle Watering-Points in the Victoria River District, Northern Australia.
Authors: Ludwig JA , Eager RW , Williams RJ , Lowe LM
Published: December 2005

In this study, we quantify the density, cover and obstruction width of vegetation patches, the roughness of landscape surfaces, and the diversities of plants and grasshoppers with distance from cattle watering- points. We used distance from water as a surrogate for a gradient in grazing pressure. Fourteen study sites were located in the Victoria River District of northern Australia, seven from a water point on Kidman Springs Station on calcareous red loam soils and seven from a water point at Mount Sanford Station on craclcing-clay black soils. At each study site transect lines were oriented within the landscape to run downslope (i.e. in the direction of flows of run-off). We measured the intercept length and obstruction width of perennial vegetation patches along these lines. Plant diversity was measured in quadrats positioned along each line and grasshopper diversity was determined by species counts on each site. We also surveyed the roughness of the landscape surface along each line. A rough surface will tend to slow run-off. hence increase time for water infiltration and soil-water storage. Surface roughness declined near water, as did the density, cover and obstruction width of perennial vegetation patches. Grasshopper and plant species richness also declined near water. These declines suggest strong linkages between landscape filmtion. biodiversity and inipacts of cattle grazing and trampling. Cattle will always create 'sacrifice zones' around watering-points. However, the area of this impact on function and diversity can be minimised by managing the timing and intensity of paddock use. Key words: grazing gradients. Kidman Springs, landscape function. Mount Sanford, piosphere, surface roughness, tropical grasslands, tropical savannas
Ecology of Sandalwood (Santalum Spicatum) Near Paynes Find and Menzies, Western Australia: Size Structure and Dry-Sided Stems.
Authors: Brand JE
Published: December 2005

Population size structure of sandalwood (Santalum spicatum) was studied on four pastoral leases near Paynes Find and Menzies, in semi-arid Western Australia. Stem diameter, height, height to crown and the orientation of dry-sided stems were recorded for 1017 individual sandalwood. Populations of S. spicatum at Paynes Find contained only mature trees, indicating no successful recruitment for at least 30 years. In contrast, populations of S, spicatum at Menzies had a high proportion of seedlings and saplings. Crown measurements of mature S. spicatum trees indicated high grazing intensity at Paynes Find: mean height to crown at Paynes Find (147-148 cm) was significantly higher than Menzies (92-94 cm). Dry-side percentage differed significantly between directional faces, consistent with sun damage. Highest mean dry-side percentages were on stem sides facing the sun between midday and late afternoon: west, north-west, south-west and north. This directional pattern was the same between pastoral leases, and there was no interaction between pastoral lease and dry-side direction. Mean percentage of mature trees with a dry-sided stem was also significantly higher at Paynes Find (76-82%) than at Menzies (42-46%). Significantly less foliage low to the ground on mature trees at Paynes Find may have exposed the stems to more sun damage. Land systems did not significantly influence dry-side direction on Burnerbinmah or Goongarrie. No S. spicatum seedlings or saplings had a dry-sided stem. Key words: Santalum spicatum, size structure, dry-sided stems
Dendritic BC1 RNA in translational control mechanisms
Authors: Wang Huidong , Iacoangeli Anna , Lin Daisy , Williams Keith , Denman Robert B. , Hellen Christopher U.T. , Tiedge Henri
Published: December 2005

Translational control at the synapse is thought to be a key determinant of neuronal plasticity. How is such control implemented? We report that small untranslated BC1 RNA is a specific effector of translational control both in vitro and in vivo. BC1 RNA, expressed in neurons and germ cells, inhibits a rate-limiting step in the assembly of translation initiation complexes. A translational repression element is contained within the unique 3′ domain of BC1 RNA. Interactions of this domain with eukaryotic initiation factor 4A and poly(A) binding protein mediate repression, indicating that the 3′ BC1 domain targets a functional interaction between these factors. In contrast, interactions of BC1 RNA with the fragile X mental retardation protein could not be documented. Thus, BC1 RNA modulates translation-dependent processes in neurons and germs cells by directly interacting with translation initiation factors.
A novel role for the CBF3 kinetochore–scaffold complex in regulating septin dynamics and cytokinesis
Authors: Gillis Amethyst N. , Thomas Scott , Hansen Scott D. , Kaplan Kenneth B.
Published: December 2005

In budding yeast, the kinetochore scaffold complex centromere binding factor 3 (CBF3) is required to form kinetochores on centromere DNA and to allow proper chromosome segregation. We have previously shown that SKP1 and SGT1 balance the assembly and turnover of CBF3 complexes, a cycle that we suggest is independent of its role in chromosome segregation (Rodrigo-Brenni, M.C., S. Thomas, D.C. Bouck, and K.B. Kaplan. 2004. Mol. Biol. Cell. 15:3366–3378). We provide evidence that this cycle contributes to a second, kinetochore-independent function of CBF3. In this study, we show that inhibiting the assembly of CBF3 causes disorganized septins and defects in cell polarity that give rise to cytokinesis failures. Specifically, we show that septin ring separation and disassembly is delayed in anaphase, suggesting that CBF3 regulates septin dynamics. Only mutations that affect the CBF3 cycle, and not mutants in outer kinetochore subunits, cause defects in septins. These results demonstrate a novel role for CBF3 in regulating cytokinesis, a role that is reminiscent of passenger proteins. Consistent with this possibility, we find that CBF3 interacts with Bir1p, the homologue of the passenger protein Survivin. Mutants in Bir1p similarly affect septin organization, leading us to propose that CBF3 and Bir1p act as passenger proteins to coordinate chromosome segregation with cytokinesis.