bluuebunny/crossref_metadata_2025 huggingface dataset:
Fire Studies in Mallee (Eucalyptus Spp.) Communities of Western New South Wales: Grass Fuel Dynamics and Associated Weather Patterns.
Authors: Noble JC , Vines RG
Published: December 2005

The probability of wildfires, or prescribed fires, occurring in mallee rangelands, is strongly dependent on availability of adequate grass fuel loads. Grass fuels comprise two major elements, a perennial component dominated by the hummock species Triodia scariosa (porcupine grass) and an ephemeral component dominated by the annual/biemial tussock species Stipa nitida (speargrass). Population dynamics and abundance of both fuel elements are, in turn, strongly influenced by rainfall regime, particularly during the seedling recruitment phase. This paper records data on the spatial distributions of different fuels, plant architecture and post-fire seedling recruitment and survivorship of T. scariosa, obtained during field studies on contrasting mallee sites in western New South Wales. In addition, rainfall data extending over c. 100 years were used in a water balance study at one mallee site (Pooncarie); while similar rainfall data were analysed for three mallee sites (Pooncarie, Ivanhoe and Mount Hope) using a filter technique to examine quasi- periodicities of rainfall and potential correlations with known wildfire seasons in the past. Precipitation records from the Meteorological Districts of western New South Wales, and from various towns in the area, were analysed as well. All data sets exhibited strong coherence and the resulting filter curves resembled each other closely, with peaks reflecting 'above-average rainfall' and troughs 'below-average rainfall or drought'- the latter often being associated with El NiiiolSouthern Oscillation events. The management implications of these phenomena, particularly as they relate to major drought events, are discussed in the context of vegetation manipulation based on prescribed fire.
Temporal Changes of Vegetation and Soil Carbon, Nitrogen and Ph on Seasonally Dry High Country, South Island, New Zealand.
Authors: Mcintosh PD , Allen RB , Patterson RG
Published: December 2005

The effects on soils and vegetation of 13 years of fertilising and grazing on previously unfertilised South Island high country are described. Vegetation cover, and the values of organic carbon, nitrogen and pH in topsoils at 38 sites sampled on a high country farm in 1978 and 1979, before any topdressing or oversowing had been begun, were compared to values at the same sites in 1992, after soils had been progressively fertilised with a total of 1100 kglha of 28% sulphur-superphosphate and oversown with legumes. In 1992 the cover of native species such as silver tussock (Poa cita), narrow-leaved snow tussock (Chionochloa rigida) and scabweed (Raoulia australis) and the area of bare ground had declined relative to cover of these species in 1978179, whereas cover of introduced pasture species tolerant of grazing had increased. Mouse-ear hawkweed (Hieraciurnpilosella) was recorded at only 4% of sites in 1978179 but was present at half the sites in 1992. Organic carbon in topsoils rose from a mean value of 3.3% in 1978179 to 5.5% in 1992. There was insignificant change of total nitrogen values. The pH of topsoils (0-7.5 cm) declined at 36 out of the 38 sites. The average pH decline was 0.41 units (from 5.81 in 1978179 to 5.40 in 1992), and the largest pH decline was 0.7 pH units. Results from an additional seven sites outside the main survey area suggest that the pH decline occurs on upper midslopes and near-ridge sites (about 10% of the land area) rather than on lower midslopes and toeslopes. If topdressing and the associated pH decline continue, then by the year 2005, pH will be close to 5.0 in topsoils, and lime will be needed to maintain legume-based pasture production on the affected soils. Approximately 1 tonne of lime per hectare every four years is estimated to be required to offset the pH decline. The present (1993) cost of applying lime is about $5.50 per stock unit per year and on present returns from livestock and wool, liming would be uneconomic.
How spatial and temporal scale affect the perception of change in rangelands.
Authors: Friedel MH
Published: December 2005

Heterogeneity in rangelands occurs at many levels, both spatially and temporally. The different levels are hierarchically ordered, from organism to landscape in the spatial context, and each has its characteristic emergent properties. Models of rangeland succession are dependent on the spatial scales of disturbance and assessment. Detectionof changes in the productive potential of rangelands is also scale dependent. Commonly, the emergent properties of lower levels, e.g, composition within communities, are used incorrectly to indicate the status of higher levels, e.g landscapes. Understanding the nature of change requires an exploration of different scales of heterogeneity.
Speargrass (Heteropogon Contortus) in Australia : Dynamics of Species and Community.
Authors: Grice AC , Mcintyre S
Published: December 2005

The perennial tallgrass Heteropogon contortus is widespread and both ecologically and economically important. It often dominates the understorey of Eucalyptus woodlands in tropical and subtropical Australia. We present an historical overview of management and research in these important grasslands and review currently available information, particularly in relation to change at the community level. The use of H, contortus communities for extensive pastoralism led to its increase at the expense of other grasses. Ecological studies sought to explain how it came to dominate large areas but much research focussed on identifying pasture species, particularly legumes, that could replace or supplement what were seen as unproductive native grasses. Other efforts were directed at improving the generally low levels of animal production that resulted from the extreme seasonality of forage quality, and examining the animal production consequences of various management actions. There is some evidence that H. contortus has declined over large areas since the 1970s, but this process and its mechanisms are not well documented. Generally, research that has taken an empirical approach to improving animal production is poorly placed to provide a comprehensive ecological understanding. This is evident in several attempts to synthesise an ecological .understanding of H. contortus communities, notably in the form of state-and-transition models. These models contain generalities, some of which have little confirmation in experimental results. The geographic range and temporal variability of H. contortus communities make it difficult to generalise on the basis of single site, short term experiments that investigate one or a few factors in isolation. There is an increasing awareness of the need for sustainable management of native and natural pastures, including the H. contortus grasslands. Meeting this need will require the maintenance of the perennial grasses of northern Australian savannas and an ecological knowledge that can predict change in a variety of circumstances and locations.
The Effects of Grazing Exclusion and Blade-Ploughing on Semi-Arid Woodland Vegetation in North-Western New South Wales Over 30 Months.
Authors: Robson AD
Published: December 2005

Inedible native shrubs are considered to be a primary cause of lost pastoral productivity in the semi- arid woodlands of north-western New South Wales. Most rehabilitation programs have focussed on reducing shrub density. In recent years blade-ploughs have been tested for this purpose. Results have been variable and most programs have brought neither lasting shrub control nor improved production for pastoralism over the medium to long term. Failure to control grazing after initial treatment is suspected as one reason for the low success rate.

An experiment involving blade-ploughing and grazing exclusion was established in July 1990 in sandplains supporting semi-arid woodlands, near Bourke New South Wales (NSW). The treatment factors were crossed and each was imposed at two levels: present and absent. Shrub density, pasture composition and pasture biomass variables were selected and measured before, and over a 30 month period following treatment. Data were analysed using repeated measures ANOVA.

The densities of Eremophila sturtii, E. deserti, E. gilesii and Dodonaea viscosa ssp. angustissima as well as that of 'Total shrubs', all increased after ploughing, irrespective of the presence or absence of grazing. In all cases except that of E, sturtii, there was no significant difference between shrub density in ploughed and unploughed plots 30 months after treatment. While E. sturtii density increased significantly to begin with, it remained significantly lower in ploughed plots compared to unploughed plots at the end of the study period. This suggests that blade-ploughing offered only temporary control of these shrubs on this land type.

Pasture biomass was significantly greater in ploughed/ungrazed plots (1300 kg/ha) compared with other treatments at the end of the study. Ploughed/ungrazed plots were the only ones where fuel had accumulated to a level which offered any possibility of burning to control shrub regeneration. The same treatment also contained a significantly greater proportion of desirable pasture species than any other treatment at the end of the study period.
The Effects of Grazing Activity on the Hydrology of the Bogong High Plains, Australia.
Authors: Lawrence RE
Published: December 2005

Stock have been grazed on the Bogong High Plains during the summer months every year for more than a century. Several severe droughts between the 1880s and 1920s resulted in abnormally large numbers of stock being depastured there in addition to the usual numbers, which contributed both to the degradation of the vegetation cover and an increase in erosion. In the 1940s, controls were placed on the number of stock permitted to graze the Bogong High Plains, and since that time total numbers 07 grazing stock have declined from 9000 cattle to just over 3000 cattle today. In this paper, historical hydrological data from the Bogong High Plains are examined to see if cattle grazing activities may be related to trends in the run-off of several streams in the subalpine and alpine zone. Long-term declining trends in both cattle grazing numbers and run-off variables were identified as statistically significant in one of the four catchments examined - albeit in the catchment with the longest run-off record. There was some evidence that the monthly run-off from three small catchments subject to differential grazing pressures supported a correlation between high grazing densities and large run-off volumes during the summer months, but this result was not substantiated by modelling daily storm hydrographs for those same months. All the hydrological data examined post-dates the period of major environmental degradation, which may have contributed to the moderate results obtained. The fact that run-off volumes declined between the 1940s and the 1980s suggests that there has been an improvement in the environmental conditions of the Bogong High Plains since grazing controls were introduced, but it is not certain whether full recovery has taken place, or ever will.
Recruitment Characteristics of the White Cypress Pine (Callitris Glaucophylla) in Arid South Australia.
Authors: Read J
Published: December 2005

Callitris glaucophylla is a long lived tree which has had limited spasmodic recruitment in the South Australian arid zone in recent years. Domestic stock and rabbit grazing have been implicated as major factors limiting its regeneration. Factors influencing the recruitment and death of C. glaucophylla in the Roxby Downs region were investigated. The survivorship of C. glaucophylla seedlings, which germinated following flooding rains in March 1989, was monitored at three rabbit densities, with and without the protection of tree guards. Despite above average rainfall in 1989, all the monitored seedlings succumbed to desiccation within 18 months of germination. Grazing by rabbits had no impact upon regeneration. In an analogous study, the height distributions of young established C. glaucophylla groves were measured and used to assign groves to cohorts representing past recruitment events. Rainfall history was compared with the estimated age of C. glaucophylla stands. Successful regeneration of C. glaucophylla in the Roxby Downs region was dependent on uncommon prolonged periods of above average rainfall. Most successful C. glaucophylla recruitment occurred in distinct groves on deep sand.
Grazing Modifies Woody and Herbaceous Components of North Queensland Woodlands.
Authors: Scanlan JC , Pressland AJ , Myles DJ
Published: December 2005

Grazed and exclosed areas within north Queensland woodlands were studied over a six-year period which included a drought followed by an above average rainfall period. Despite drought conditions, woody plant density increased, with exclosed areas showing a greater increase than grazed areas. During the drought period, a pattern of herbaceous vegetation strips interspersed with bare areas developed. Standing dry matter and ground cover increased rapidly in response to above average rainfall following the drought. Also, the pattern of strips became less apparent during the more favourable growth conditions. The percentage contribution of native tussock grasses (principally Heteropogon contortus) to total pasture dry matter varied to a greater extent over the six-year period than the naturalised stoloniferous Bothriochloa pertusa.
Establishment of Woody Weeds in Western New South Wales. 1. Seedling Emergence and Phenology.
Authors: Booth CA , King GW , Sanchez-Bayo F
Published: December 2005

Germination and survival of seedlings of four woody weed species (narrow-leaved hopbush Dodonaea attenuata, turpentine Eremophila sturtii, punty bush Cassia Eremophila var. Eremophila and silver cassia C. artemisioides) were examined, together with their phenology, at four sites which differed in shrub density, grazing pressure and topography in the Bourke - Wanaaring region of western New South Wales over the period 1979 to 1982. Although emergence varied between species (D. attenuata: 5,000-30,000 seedlings/ha; E. sturtii: 3,000-10,000 seedlings/ha; Cassia spp. : 2,000-4,000 seedlings/ha), the conditions favourable to large scale establishment depended mainly on rainfall during late autumn and winter for germination and that of the summer following germination for survival of all species. Turpentine required larger rainfall events or prior rainfall events for seedling germination. Soil disturbance enhanced seedling emergence, growth and survival of D. attenuata., by increasing soil moisture content deep in the profile. Sandhill areas showed significantly higher emergence levels for D. attenuata. The higher emergence of seedlings on densely shrubbed areas was most probably due to higher soil seed loads. Micro-depressions and sandplains favoured survival of all species. Grazing, mainly by rabbits, had no specific impact on emergence of any of the species, but reduced the survivorship of D. attenuata. Predation by insects had a negligible effect.

Hopbush flowered in all years between July and October and turpentine flowered from May to September. Those that flowered were prolific. Seed loads had been dropped by late November. Generally, hopbush shrubs had attained 2 m before flowering but in one year 86% of those above 1 m high flowered. Turpentine generally flowered after it had attained 50 cm, although in one year one plant flowered when less than 25 cm.

Encroaching populations of shrubs should be controlled before they mature and form dense stands. Hopbush and turpentine control programs should be completed before the end of winter, just before annual seed set. Control of young establishing stands of hopbush should be undertaken before they reach a height of one metre and 50 cm for turpentine. Rapid expansion outside treated areas is unlikely, however, occasional 'outlier' shrubs should be controlled before they mature and produce seed.
Establishment of Woody Weeds in Western New South Wales. 2. Growth and Competitive Potential.
Authors: Booth CA , Sanchez-Bayo F , King GW
Published: December 2005

Growth and survival of hopbush (Dodonaea attenuata), turpentine (Eremophila sturtii) and punty bushes (Cassia eremophila and C. artemisioides) were studied in relation to the effects of grazing and shrub density, at four sites in the Bourke-Wanaaring region of western New South Wales during 1979 to 1982. Hopbush shrubs grew faster than turpentine and punty bushes. Small hopbush grew better on open areas, while mature shrubs grew better in dense stands. Turpentine showed better performance in open areas, and punty bush growth was unaffected by shrub population density. All these species showed a high survival rate, particularly in height classes greater than 25 cm, and they kept growing even during drought periods. The effects of grazing on survival were inconclusive. Hopbush and turpentine root development was rapid, attaining depths of over 1.1 m in wet soils, 14 weeks after germination. Mature plants in the field, both hopbush and turpentine, were observed to have extensive lateral root networks at either 22 cm or 30-70 cm soil depth respectively, as well as a tap root system. The characteristics of both species help explain the competitive advantage of these shrubs over herbaceous species, and their survival capability in times of drought. Competition of hopbush with the perennial grass woollybutt (Eragrostis eriopoda) and annual herbage was also examined. In spring, survival of hopbush seedlings was favoured within woollybutt tussocks, this situation being reversed in autumn. Woollybutt biomass was negatively affected by the proximity of hopbush shrubs. Annual herbage seemed not to have any effect on hopbush survival, although shrub seedlings grew better under conditions of moderate herbage cover. Microtopography affected the establishment of both grasses and shrubs, with depressions favouring the growth of grasses at the expense of shrubs during periods of adequate moisture, and the growth of shrubs during drier times. The findings suggest that the woody weed problem is unlikely to wax and wane and that turpentine may be particularly difficult to control. Maintenance of high levels of pasture cover from perennial grasses and annuals may slow down recruitment and growth in open areas with scattered parent shrubs, where control will be less costly, and may contain future spread.
Estimating Landscape Resilience From Satellite Data and Its Application to Pastoral Land Management.
Authors: Bastin GN , Pickup G , Stanes J , Stanes A
Published: December 2005

Episodic rainfall provides infrequent opportunities for vegetation recovery from grazing in the arid rangelands. The magnitude of resultant vegetation growth, or resilience, varies widely in space and is not simply controlled by rainfall amount or past grazing practices. The non predictable nature of vegetation response fits within the model of nonequilibrium rangeland behaviour and we propose use of the Resilience Method as a means of spatially assessing vegetation resilience, or the ability of herbage to respond to infrequent rainfall. Information required to calculate an index of resilience is obtained from remotely-sensed satellite data, is plant cover-based and is processed to produce landscape-scale maps of vegetation resilience. In this paper, we demonstrate and evaluate products developed to transfer the Resilience Method to a pastoralist family to assist in their future property management. These products include maps of scaled herbage response to rainfall, herbage response in conjunction with dry period vegetation cover and herbage biomass derived from vegetation cover. The cover-based products effectively showed herbage response following a large rainfall. Much of the variation in response was natural and was related to timber density and soil factors. Some areas with below average herbage response were attributable to damage caused by high rabbit populations. Herbage response on much of the productive grazing country was average to above average indicating good resilience and potential for continued beef production. The resilience approach to landscape assessment provided a useful pictorial representation of herbage response across the whole station following one rainfall. The participating pastoralists consider that the Resilience Method will have greater validity when repeated following further significant rainfalls. Some insights were gained into future property development. However, the technology was difficult to understand and requires a close liaison between the technician and client. Confusion arose where below average herbage response could occur in areas of both high and low initial cover when the two areas appear vastly different and require separate management for beef production and rehabilitation. Both the nonequilibrium approach to understanding vegetation dynamics and the Resilience Method need further explanation and demonstration before they are accepted as being useful for pastoral land management.
Assessing the Risk of Various Stocking Strategies in the Semi-Arid Savanna of Kwazulu-Natal, South Africa.
Authors: Hatch GP , Tainton NM , Ortmann GF
Published: December 2005

Rainfall in arid and semi-arid environments is a major determinant of system dynamics which results in seasonal fluctuations in forage production. The influence of fixed and variable stocking strategies on the distributions of forage deficit period and net return for various range condition scenarios were examined using a bioeconomic model. Although the risk of forage deficits and financial losses were reduced with lighter stocking, this was at the opportunity cost of higher returns during wetter seasons. Increased stocking increased returns during wetter seasons, but at the cost of increased risk of forage deficits and highly negative returns during drier seasons. Flexible stocking may combine the benefits of each approach and reduce financial risk. The development of cumulative probability distributions will allow range users to assess the level of risk attached to different strategies. Incorporation of the ecological effects of stocking strategies as feedback into the model would be important to evaluate ecological risk.
Home Range Responses of Feral Goats.
Authors: Holt C , Pickles G
Published: December 2005

The variability in size and the extent of the overlap of feral goat home ranges are important considerations when formulating control strategies. Radio telemetry data revealed home range sizes were similar to what was found in other studies performed in pastoral areas. This study confirms the need for a wide ranging cooperative approach, by neighbouring pastoral properties, to feral goat control if all the feral goats using an area are to be targeted. Aerial control activities had little effect on the home ranges of resident feral goats and so can continue to be an effective control tool without causing the reinfestation of previously cleared areas.
Recruitment of Curly Mitchell Grass (Astrebla Lappacea) in North-Western New South Wales.
Authors: Campbell MH , Bowman AM , Bellotti WD , Munich DJ , Nicol HI
Published: December 2005

The recruitment of Astrebla lappacea was studied from 1986 to 1995 in a pasture in north-western NSW where the density of plants had declined from 1 to 3 plants/m2 in 1970 to 0.023 plants/m2 in 1986. Three treatments were imposed: ungrazed-sprayed-slashed, where annual weeds were treated with herbicides and slashing to reduce competition during recruitment; ungrazed-only; and grazed-only. The seed bank of A. lappacea was measured on four occasions and densities of A. lappacea plants determined after major rainfall events mainly in summer and autumn. On the ungrazed treatments the seed bank of A. lappacea increased from 0 in 1988 to 908, 898 and 286 germinable seed/m2 in, respectively, 1992, 1993 and 1995. Flowering and seedling recruitment occurred each year from 1988 to 1995 but seedlings only survived to become mature plants from the 1988 and 1992 recruitments. The major reason for the death of seedlings was dry conditions in the latter half of the year (1 10 to 135 mm of raid6 months). Frosts and competition from Brassicaceae weeds (mainly Raphistrum rugosum) in winter and spring also contributed to death of seedlings. Recruitment of seedlings and their survival to mature plants was higher on the ungrazed-sprayed-slashed treatment than on the other treatments. Recruitment and survival on the ungrazed-only treatment occurred because Brassicaceae weeds did not establish when recruiting rains fell in summer. Plant densit increased from 0.023 plants/m2 in 1986 to, respectively, 0.86, 0.64 Y and 0.004 mature plantdm and 7.88, 6.37, 0.10 seedlings/m2 on the ungrazed-sprayed-slashed, ungrazed-only and grazed-only treatments in 1995. On the grazed-only treatment the methods used to detect seeds revealed none in the soil during the experiment. However, some seeds were present because there was a low level of recruitment none of which survived to mature plants. The number of mature plants declined from 0.023 to 0.004/m2 indicating that under the present grazing system the complete elimination of A. lappacea from pastures in north-western NSW is possible if some form of managed recruitment is not devised.
Managing Drought in Australia's Rangelands: Four Weddings and a Funeral.
Authors: Buxton R , Smith MS
Published: December 2005

We report some of the findings of a project called 'DroughtPlan', which has involved close collaboration with pastoralists throughout the Australian rangelands. There were three general areas related to property management where producers felt better information and training could help them cope with climatic variability. These were strategic management of long-term stocking levels, tactical management of stock numbers between years, and business management skills.

A comprehensive series of representative studies linking herd biology with economic outcomes was undertaken on these topics with pastoralists in different regions of the rangelands. Some of the studies considered most important by pastoralists are reported here. These demonstrate that: (i) a reduction in current stocking levels can often improve cash flow; (ii) small adjustments in livestock selling tactics during drought can have large financial ramifications; (iii) it is financially advantageous to build stock numbers up quickly after a drought, even though this may conflict with longer-term environmental values; (iv) while diversification can provide financial rewards, these could be matched by small improvements in the biological rates of the livestock; and, (v) fine-tuning of the existing pastoral enterprise can provide a less risky means of increasing cash flow and reducing its variability than does diversification. Four of the examples indicate that better use of information can help both profitability and sustainability; the fifth suggests that the interests of short-term profitability are in conflict with long-term land conservation goals, as assessed by many pastoralists.

These studies highlight the value of linking producer knowledge with a systematic analysis framework, as well as the vital importance of incorporating the effects of climatic variability, when assessing the value of different management options.
Choosing Appropriate Taxonomic Units for Ecological Survey and Experimentation: the Response of Aristida to Management and Landscape Factors as an Example.
Authors: Mcintyre S , Filet PG
Published: December 2005

The use of appropriate taxonomic units to describe herbaceous vegetation is an issue of increasing importance due to developing interest in the effects of grazing and other management on plant diversity in pastures. We use data for the genus Aristida as an example to examine patterns of ecological response to grazing, pasture sowing and landscape position in different taxonomic units. Responses of Aristida at the level of genus, section and species were compared over the gradients. There was strong evidence of differential responses to these factors, both between sections within genus, and between species within sections. The planning and execution of botanical field descriptions involve striking a balance between taxonomic accuracy and precision that will best address the objectives of a particular project. The species of the genus Aristida have a range of ecological responses, the variety of which can not be captured in data sets which record Aristida as a single entity. As a result, management recommendations for the genus in its entirety are likely to be inaccurate. Although data collection might ideally record individual species, this is not always practicable. In any case, there may be many rare species in the data set, with occurrences too low to detect ecological pattern. Delineation of rare species may only be important if diversity issues are being examined. In other circumstances the use of an intermediate unit (e.g. section or species groups) may be appropriate. The latter approach may be required if there are practical limitations to the collection of data at specific level for all groups, or if the research objectives do not require a high level of precision.
The Efficacy of Finlayson Troughs as a Means of Repelling Kangaroos From Water and Altering Grazing Pressure in Pastoral Areas.
Authors: King DR , Norbury GL , Eliot GJ
Published: December 2005

We attempted to determine whether Finlayson troughs (a selective electric repellent device) would repel kangaroos (Macropus rufus and M. robustus) but still allow sheep to drink when access of kangaroos to artificial water sources was restricted on a large scale, and the effect that had on kangaroo populations.

In late 1993 high percentages of kangaroos (over 80% of both species) were repelled from water sources fitted with Finlayson troughs when alternative water sources were available. However, when all water sources within a 100,000 ha area had activated Finlayson troughs or were fenced off, kangaroos found methods that enabled them to circumvent the Finlayson troughs within two weeks after activation of the troughs. The numbers which were able to obtain a drink increased greatly over this period. When used on a large scale, Finlayson troughs as used in this study were thus apparently ineffective in restricting the access of kangaroos to water.

Aerial surveys and radio-tracking were used to determine the numbers and distribution of kangaroos over the whole area after activation of all the Finlayson troughs. There were no significant differences in kangaroo numbers between the treated area and a nearby control area which was devoid of Finlayson troughs. All 31 of the radio-collared kangaroos which could be located at the end of the trial remained within the areas they formerly occupied and the length of their movements did not increase.
Learning From History to Survive in the Future: Management Evolution on Trafalgar Station, North-East Queensland.
Authors: Landsberg RG , Ash AJ , Shepherd RK , Mckeon GM
Published: December 2005

Managing rangeland enterprises requires balancing socio-economic goals within a production environment characterised by ecological complexity and large climatic variability. Trafalgar Station in north-east Queensland, has been trying to maintain this balance over a period of 80 years and three generations of the one family. This paper explores how management on Trafalgar Station has gone through four evolutionary phases and examines the advantages and disadvantages of each of these stages of development. The first 50 years of management was a technologically constrained era of low stock numbers and poor productivity but there were few resource management problems. Next followed a 20 year period of production maximisation which was made possible by improved cattle genetics and nutritional technologies. With drought feeding occurring more frequently and loss of perennial grasses and soil becoming more evident, there came the realisation that this high stocking strategy was unsustainable. The management of Trafalgar then embarked on a new philosophy based on conservative stocking (similar to historical levels) and increased emphasis on herd, pasture and financial management. This new management philosophy required a transitional phase where stock numbers. and income, were very low to allow pasture condition to improve. Current herd management focuses on maintaining quality rather than quantity, strategic use of supplements for production, and developing a diverse range of markets for sale cattle. Conservative stock numbers have increased opportunities in pasture management with 15 to 20% of the property now annually rested from grazing. Fire has been reintroduced to restrict "thickening" of native woody plants and to control exotic woody weeds. Together with long-term financial planning, these improvements in management are reducing economic risk. The perceived benefits of the current management philosophy are supported by simulation modelling studies of pasture and animal production and analyses of property economics.
Lakes and Lakebed Cropping in the Western Division of New South Wales.
Authors: Seddon JA , Briggs SV
Published: December 2005

We developed an inventory of all lakes 100 ha or greater in area in the Western Division of New South Wales including information on source of water, salinity, water regime, lake area, and presence of cultivation permits. Number, area and distribution of different categories of lakes were summarised, and the use of lakes for cropping (lakebed cultivation) and water storage were analysed by category of lake. There were 567 lakes 100 ha or larger in area in the Western Division. The majority of these were mainly dry (includes dry lakes) (56%) or filled intermittently (40%), usually from river flooding. Just under 5% of lakes were perennial. Water regimes in most perennial lakes were controlled by local structures. Seventy lakes had lakebed cultivation permits. Twenty per cent of fresh lakes that filled from a river, rather than from local rainfall, in the Western Division of New South Wales were cultivated (i.e. cropped). Eighty per cent of fresh, riverine lakes larger than 2000 ha which flood and dry intermittently were cultivated. Lakebed cropping in the Western Division of New South Wales has focused on large, fresh, lakes which fill intermittently from rivers. Use of lakes as water storages has also focused on large, fresh lakes. Conservation strategies are recommended for large, fresh lakes that flood intermittently from a river, and are not cropped or used as water storages. These strategies should be directed towards developing voluntary conservation agreements with landholders. Key words: lakes, cropping, GIS, water regimes, conservation
An Evaluation of a Long-Term Feral Goat Control Program in Mootwingee National Park and Coturaundee Nature Reserve, Far Western New South Wales.
Authors: Sharp A , Holmes K , Norton M
Published: December 2005

Between January 1981 and September 1997, goat mustering and aerial culling was conducted on
Mootwingee National Park and Coturaundee Nature Reserve, an area with high densities of goats
(Southwell et al. 1993). The goat control campaign was initiated as a general management strategy to
reduce the negative impacts of goats on native vegetation, aboriginal art sites and the endangered yellowfooted
rock-wallaby (Petvogale xanthopus). During this period a total of 42,516 goats were removed
(13,089 mustered, 29,427 shot). Between January 1988 and June 1995 it was possible to calculate
population indices for goats using aerial culling data; Ln(number of goats shotlminute flying time+l).
The study site was sub-divided into northern and southern blocks and population indices calculated for
each block. Linear regression equations were fitted to the population indices plotted across time. The data
suggest that despite the removal of considerable numbers of goats from both blocks of the study area
(1 1,601, northern; 10,035, southern), there was no detectable decrease in goat numbers over the 1988-
1995 period. For both blocks the slope of the regression line was negative and close to zero (-0.005,
northern; -0.0003, southern). The results indicate that the impact of mustering and shooting was shortterm
and that the re-invasion rate by goats into the area was very high. In areas of high goat density,
control measures need to be regular and conducted over a broad geographic area if goat numbers are to
be effectively reduced. No detectable increase was noted in the yellow-footed rock-wallaby population
during the period of intensive goat control.
Response of Birds and Reptiles to Fire Regimes on Pastoral Land in the Victoria River District, Northern Territory.
Authors: Woinarski JCZ , Brock C , Fisher A , Milne D , Oliver B
Published: December 2005

Birds and reptiles were censused at two sites of contrasting soil texture (clay, loam) on pastoral land in the Victoria River District, Northern Territory. Both sites comprised 16 plots (each of 2.6 ha) subjected to seven different experimental fire regimes (unburnt, burnt in the early dry season at 2, 4 and 6 year intervals, and burnt in the late dry season at 2, 4 and 6 year intervals) beginning five years before sampling (and thus, not all regimes had been operationally distinct between the onset of the experiment and this sampling). The regimes were deconstructed to four fire factors: the imposed regime, the time since last fire, the number of fires since the inception of the experiment, and the number of hot (=late dry season) fires. Of 30 species recorded from at least four plots, 12 were significantly associated with time since last fire. These responses were mostly to the extremes - some species were associated with the most recently burnt areas, and others occurred mainly in the plots which had been unburnt the longest. Longer- term responses to fire regimes were generally less clearcut, possibly because the relatively short duration of the imposed experimental fire treatments had not yet brought about substantial environmental divergence. Key words: fire regime, tropical savannas, birds, reptiles, diversity.
Quantification of the effect of vaccination on transmission of avian influenza (H7N7) in chickens
Authors: van der Goot J. A. , Koch G. , de Jong M. C. M. , van Boven M.
Published: December 2005

Recent outbreaks of highly pathogenic avian influenza (HPAI) viruses in poultry and their threatening zoonotic consequences emphasize the need for effective control measures. Although vaccination of poultry against avian influenza provides a potentially attractive control measure, little is known about the effect of vaccination on epidemiologically relevant parameters, such as transmissibility and the infectious period. We used transmission experiments to study the effect of vaccination on the transmission characteristics of HPAI A/Chicken/Netherlands/03 H7N7 in chickens. In the experiments, a number of infected and uninfected chickens is housed together and the infection chain is monitored by virus isolation and serology. Analysis is based on a stochastic susceptible, latently infected, infectious, recovered (SEIR) epidemic model. We found that vaccination is able to reduce the transmission level to such an extent that a major outbreak is prevented, important variables being the type of vaccine (H7N1 or H7N3) and the moment of challenge after vaccination. Two weeks after vaccination, both vaccines completely block transmission. One week after vaccination, the H7N1 vaccine is better than the H7N3 vaccine at reducing the spread of the H7N7 virus. We discuss the implications of these findings for the use of vaccination programs in poultry and the value of transmission experiments in the process of choosing vaccine.
MicroRNAs 221 and 222 inhibit normal erythropoiesis and erythroleukemic cell growth via kit receptor down-modulation
Authors: Felli Nadia , Fontana Laura , Pelosi Elvira , Botta Rosanna , Bonci Desirée , Facchiano Francesco , Liuzzi Francesca , Lulli Valentina , Morsilli Ornella , Santoro Simona , Valtieri Mauro , Calin George Adrian , Liu Chang-Gong , Sorrentino Antonio , Croce Carlo M. , Peschle Cesare
Published: December 2005

MicroRNAs (miRs) are small noncoding RNAs that regulate gene expression primarily through translational repression. In erythropoietic (E) culture of cord blood CD34+ progenitor cells, the level of miR 221 and 222 is gradually and sharply down-modulated. Hypothetically, this decline could promote erythropoiesis by unblocking expression of key functional proteins. Indeed, (
i
) bioinformatic analysis suggested that miR 221 and 222 target the 3′ UTR of kit mRNA; (
ii
) the luciferase assay confirmed that both miRs directly interact with the kit mRNA target site; and (
iii
) in E culture undergoing exponential cell growth, miR down-modulation is inversely related to increasing kit protein expression, whereas the kit mRNA level is relatively stable. Functional studies show that treatment of CD34+ progenitors with miR 221 and 222, via oligonucleotide transfection or lentiviral vector infection, causes impaired proliferation and accelerated differentiation of E cells, coupled with down-modulation of kit protein: this phenomenon, observed in E culture releasing endogenous kit ligand, is magnified in E culture supplemented with kit ligand. Furthermore, transplantation experiments in NOD-SCID mice reveal that miR 221 and 222 treatment of CD34+ cells impairs their engraftment capacity and stem cell activity. Finally, miR 221 and 222 gene transfer impairs proliferation of the kit+ TF-1 erythroleukemic cell line. Altogether, our studies indicate that the decline of miR 221 and 222 during exponential E growth unblocks kit protein production at mRNA level, thus leading to expansion of early erythroblasts. Furthermore, the results on kit+ erythroleukemic cells suggest a potential role of these miRs in cancer therapy.
A human transporter protein that mediates the final excretion step for toxic organic cations
Authors: Otsuka Masato , Matsumoto Takuya , Morimoto Riyo , Arioka Shigeo , Omote Hiroshi , Moriyama Yoshinori
Published: December 2005

In mammals, toxic electrolytes of endogenous and exogenous origin are excreted through the urine and bile. Before excretion, these compounds cross numerous cellular membranes in a transporter-mediated manner. However, the protein transporters involved in the final excretion step are poorly understood. Here, we show that MATE1, a human and mouse orthologue of the multidrug and toxin extrusion family conferring multidrug resistance on bacteria, is primarily expressed in the kidney and liver, where it is localized to the luminal membranes of the urinary tubules and bile canaliculi. When expressed in HEK293 cells, MATE1 mediates H
+
-coupled electroneutral exchange of tetraethylammonium and 1-methyl-4-phenylpyridinium. Its substrate specificity is similar to those of renal and hepatic H
+
-coupled organic cations (OCs) export. Thus, MATE1 appears to be the long searched for polyspecific OC exporter that directly transports toxic OCs into urine and bile.
Pharmacological modulation of pain-related brain activity during normal and central sensitization states in humans
Authors: Iannetti G. D. , Zambreanu L. , Wise R. G. , Buchanan T. J. , Huggins J. P. , Smart T. S. , Vennart W. , Tracey I.
Published: December 2005

Abnormal processing of somatosensory inputs in the central nervous system (central sensitization) is the mechanism accounting for the enhanced pain sensitivity in the skin surrounding tissue injury (secondary hyperalgesia). Secondary hyperalgesia shares clinical characteristics with neurogenic hyperalgesia in patients with neuropathic pain. Abnormal brain responses to somatosensory stimuli have been found in patients with hyperalgesia as well as in normal subjects during experimental central sensitization. The aim of this study was to assess the effects of gabapentin, a drug effective in neuropathic pain patients, on brain processing of nociceptive information in normal and central sensitization states. Using functional magnetic resonance imaging (fMRI) in normal volunteers, we studied the gabapentin-induced modulation of brain activity in response to nociceptive mechanical stimulation of normal skin and capsaicin-induced secondary hyperalgesia. The dose of gabapentin was 1,800 mg
per os
, in a single administration. We found that (
i
) gabapentin reduced the activations in the bilateral operculoinsular cortex, independently of the presence of central sensitization; (
ii
) gabapentin reduced the activation in the brainstem, only during central sensitization; (
iii
) gabapentin suppressed stimulus-induced deactivations, only during central sensitization; this effect was more robust than the effect on brain activation. The observed drug-induced effects were not due to changes in the baseline fMRI signal. These findings indicate that gabapentin has a measurable antinociceptive effect and a stronger antihyperalgesic effect most evident in the brain areas undergoing deactivation, thus supporting the concept that gabapentin is more effective in modulating nociceptive transmission when central sensitization is present.
A UV-B-specific signaling component orchestrates plant UV protection
Authors: Brown Bobby A. , Cloix Catherine , Jiang Guang Huai , Kaiserli Eirini , Herzyk Pawel , Kliebenstein Daniel J. , Jenkins Gareth I.
Published: December 2005

UV-B radiation in sunlight has diverse effects on humans, animals, plants, and microorganisms. UV-B can cause damage to molecules and cells, and consequently organisms need to protect against and repair UV damage to survive in sunlight. In plants, low nondamaging levels of UV-B stimulate transcription of genes involved in UV-protective responses. However, remarkably little is known about the underlying mechanisms of UV-B perception and signal transduction. Here we report that
Arabidopsis
UV RESISTANCE LOCUS 8 (UVR8) is a UV-B-specific signaling component that orchestrates expression of a range of genes with vital UV-protective functions. Moreover, we show that UVR8 regulates expression of the transcription factor HY5 specifically when the plant is exposed to UV-B. We demonstrate that HY5 is a key effector of the UVR8 pathway, and that it is required for survival under UV-B radiation. UVR8 has sequence similarity to the eukaryotic guanine nucleotide exchange factor RCC1, but we found that it has little exchange activity. However, UVR8, like RCC1, is located principally in the nucleus and associates with chromatin via histones. Chromatin immunoprecipitation showed that UVR8 associates with chromatin in the
HY5
promoter region, providing a mechanistic basis for its involvement in regulating transcription. We conclude that UVR8 defines a UV-B-specific signaling pathway in plants that orchestrates the protective gene expression responses to UV-B required for plant survival in sunlight.
Dissecting the Fine Details of Assembly of a T = 3 Phage Capsid
Authors: Stockley P. G. , Ashcroft A. E. , Francese S. , Thompson G. S. , Ranson N. A. , Smith A. M. , Homans S. W. , Stonehouse N. J.
Published: December 2005

The RNA bacteriophages represent ideal model systems in which to probe the detailed assembly pathway for the formation of a T = 3 quasi‐equivalent capsid. For MS2, the assembly reaction can be probed in vitro using acid disassembled coat protein subunits and a short (19 nt) RNA stem‐loop that acts as the translational operator of the replicase gene and leads to sequence‐specific sequestration and packaging of the cognate phage RNA in vivo. Reassembly reactions can be initiated by mixing these components at neutral pH. The molecular basis of the sequence‐specific RNA–protein interaction is now well understood. Recent NMR studies on the protein demonstrate extensive mobility in the loops of the polypeptide that alter their conformations to form the quasi‐equivalent conformers of the final capsid. It seems reasonable to assume that RNA binding results in reduction of this flexibility. However, mass spectrometry suggests that these RNA–protein complexes may only provide one type of quasi‐equivalent capsid building block competent to form five‐fold axes but not the full shell. Work with longer RNAs suggests that the RNA may actively template the assembly pathway providing a partial explanation of how conformers are selected in the growing shell.