bluuebunny/crossref_metadata_2025 huggingface dataset:
Grazing intensity of cattle on a complex of rangeland communities in Central Australia.
Authors: Low WA , Muller WJ , Dudzinski ML
Published: December 2005

Distribution of cattle grazing the rangeland communities of Kunoth Paddock in central Australia was determined from aerial surveys at fortnightly intervals over a 4.5 year period. Mean density throughout the study was 3.5 cattle/km2 and varied between communities from 8.0 cattle/km2 to 0.4 cattle/km2 on the major communities and from 25.6 cattle/km2 to 3.2 cattle/km2 on the minor communities. Cow-days of use were calculated for seasonal intervals to show grazing intensity on the communities over ti~ne. Grazing concentrations throughout the study revealed three groups of utilization levels of the major communities. Foothill fans, Woodlands, Floodplains and Gilgaied plains received about twice the mean grazing intensity for the paddock. Mulga-annual grass received about average grazing intensity and Hills and Mulga-perennial grass received less than half the average grazing intensity. Our sti~dy shows that cattle graze range communities differentially in a free-ranging situation. This information is useful in interpreting results of range condition and trend studies, and also suggests that more uniform utilization of all the communities might be obtained by controlhng grazing distribution.
Response of an Astrebla Spp. grassland to heavy grazing by cattle and light grazing by sheep in North-west Queensland.
Authors: Hall TJ , Lee GR
Published: December 2005

Botanical changes were measured in a semi-arid, Asrrebla lappacea (Mitchell grass) dominant grassland in the summer rainfall region of north-west Queensland that has been grazed traditionally by Merino sheep. Cattle have been introduced recently in large numbers and the effects of heavy grazing by cattle on these pastures in the dry season is unknown. A paddock v\as sub-divided and t\%o grazing treatments were applied in 1971. For seven consecutive years, steers were grazed at 70 to 141 beast grazing days per hectare per annum in the late dry season and compared with sheep grazing at equivalent to 17 to 37 beast grazing days per hectare per annum. Compared with light grazing, the heavy grazing treatment caused: an increased number but smaller Astrebia spp. plants; lower basal cover; reduced standing dry matter yield; reduced root yield; increased annual grass population and yield; reduced Aris- rida lar[f?jlia (feathertop) population; and an increased number of forbs.
Seedling growth on Mulga soils and the ameliorating effects of lime, phosphate fertilizer and surface soil from beneath poplar box trees.
Authors: Silcock RG
Published: December 2005

Phosphate fertilizer, lime (CaCO3), and soil from beneath poplar box trees (Eucalyptus populnea) were incorporated into the surface of an acid sandy red earth (mulga soil) in pots. The effect of these treatments was studied on the growth rate and yield of seedlings of 7 exotic pasture species, Cenchrus ciliaris cv. Biloela, C. ciliaris Q10087, C. ciliaris Q10077. Schmidtia pappophoroides, Eragrostis curvula CPI 30379, Anthephora pubescens and Stylosanthes fruticosa, plus 3 native species Monachather paradoxa, Digitaria ammophila and Aristida armata.

Phosphate fertilizer significantly increased growth rates and yields on all soils of all species except E. curvula, S. fruticosa, M. paradoxa and A. armata.

Lime, sufficient to raise the pH from 4.8 to 7.7, only slightly improved plant growth overall, although the effect was significant on the three C. ciliaris lines in the absence of added phosphorus. Box surface soil significantly increased growth rate and size of C. ciliaris, especially the cultivar Biloela, and to a lesser extent that of A. pubescens, M. paradoxa and .T. pappophoroides. This improvement in seedling growth on soil from beneath box trees could be at least matched by the addition of phosphorus to mulga soil. Yet the shoots of seedlings growing in box surface soil appeared deficient in phosphorus, indicating a lower availability to plants of such phosphorus than chemical tests would indicate. Evidence in research literature indicates that the results obtained point to aluminium toxicity as being a major factor limiting seedling growth of C. ciliaris on mulga soils.
The effects of sulphur and phosphorus on the yield and composition of some indigenous and naturalized legumes on the North-West Slopes of New South Wales.
Authors: Lodge GM
Published: December 2005

Indigenous, naturalized and commercial legume species were grown in pot culture, at five levels of applied sulphur as sodium sulphate (0, 10, 15, 25 and 35 kg ha-') and phosphorus as sodium dihydrogen phosphate (0, 6, 15, 23 and 29 kg ha-'). The dry matter yield and sulphur and phosphorus concentration in the plant tops were determined and critical percentages of sulphur and phosphorus established. In the presence of adequate sulphur and phosphorus the species yields ranked in the order Trifbliunz rubtcrranertrn L > T. glorneratum L > Medicago trumatula J Gaertn > M. polymorpha L 2 M. minima L (Bart) > Gl,wiize tabacirza (Labill) Benth, but only for the Trifolium species were both sulphur and phosphorus essential for high yields. Sulphur deficiency symptoms of chlorotic leaves were observed in the So treatments for all species except G tabac~m In general sulphur deficiency in these species was indicated by sulphur content less than 0.2%, a nitrogen to sulphur ratio greater than 20.1 in the plant tops and a low proportion of laminae. No phosphorus deficiency symptoms were observed in any of the species growing in the Po treatments, though phosphorus percentages ranged from 0.15-0.22. The critical sulphur and phosphorus percentages in the plant tops of these species at flowering ranged from 0.17-0.32 for sulphur and 0.24-0.32 for phosphorus.
The influence of grazing by cattle and sheep on the population dynamics of Bladder Saltbush (Atriplex Vesicaria) and white top (Danthonia caespitosa).
Authors: Graetz RD
Published: December 2005

Plant population data for the pass white-top (Danthonia caespitosa) and for bladder saltbush (Atriplex vesicaria) were collected for four years from a pasture continuously grazed by either cattle or sheep (at equivalent stocking rates) at a site near Booligal, New South Wales.

During the four years of the experiment the cattle and sheep had different Impacts on the grass and scrub components of the pasture Sheep tended to deplete the numbers of pass plants far more than did cattle, whereas saltbush shrub numbers here little affected by either type of stock. The rainfall pattern experienced throughout the experiment had a far greater influence on the survival of both grass and shrub than did grazing.
Changes in the distribution of Poplar Box (Eucalyptus populnea) on major soil groups: An application of the log-linear model.
Authors: Cunningham RB , Webb AA , Mortlock A
Published: December 2005

The association of poplar box (Eucalyptus populnea) with five main soil groups is examined. A statistical analysis, using a log- linear model, indicated that the relative frequencies of poplar box sites occumng on major soil groups changed with geographic location. The change in distribution is shown to relate to climate, as indicated by summer and winter moisture indices and the diff- erence between them. This study illustrates the use of log-linear models in ecology; such models, and more generally, Generalized Linear Models, in providing significance tests, have advantages over the non-statistical methods of gradient analysis.
Distribution of Grey Kangaroos in South, Inland Queensland.
Authors: Hill GJE
Published: December 2005

An aerial survey of eastern grey kangaroo (Mecropusgiganteus) density was 2onducted during August 1979 for a 47,100 km2 strip of southern, inland Queensland. A population estimate of 694,180 + 5 3,065 (Y + SE) was obtained. LANDSAT band 5 imagery was used to defme broadscale habitat zones for the study area. An analysis was made of the relationship between kangaroo distribu- tion and the habitat zones. Results indicated that habitat data at this scale forms a useful base for the design of aerial surveys.
Techniques for estimating plant basal area and assessing the herbage mass of some native perennial grasses.
Authors: Lodge GM , Taylor JA , Whalley RDB
Published: December 2005

Techniques for using grid and unmarked transparent perspex overlays to estimate the area of tufted native perennial grasses were investigated in field and laboratory studies. Basal area was overestimated by using an unmarked overlay to trace the periphery of actual or atificial plant bases at ground level; this was caused by the amount of airspace included in the estimate. The compression of hand-held tufts reduced the airspace and improved the estimate of plant basal area. In the laboratory studies, the estimation by eye of filled cells in a transparent grid overlay was accurate over a range of areas from 0.02 to 10.39 cm2, although it required considerable operator training. Changes in herbage mass occur as a result of change in the number of plants per unit area (plant density), the basal area of individual plants or the plant mass per unit of basal area of individual plants. Field studies were undertaken at two sites to collect data on each of these components of herbage mass and to investigate whether or not such information could be used to estimate the herbage mass of individual species in a pasture. The relationship between the mass per unit basal area of certain plant parts would appear to have some potential for use in studies of the seasonal changes in various plant components, such as green leaf and stem. This relationship could be used to examine the response of some species to fertilizer application, grazing and defoliation and hence the process of change in species composition with management. Estimates of the herbage mass per unit area of individual native perennial grasses calculated from plant density, plant basal area and mass per unit of basal area data compared favourably with estimates of total herbage mass of individual species obtained from clipped quadrats. Suggested techniques for collecting data in the field and the time involved in sampling are discussed.
The response of weaner cattle grazing natural pastures in north western Australia to phosphoric acid, non protein nitrogen and sulphur in their drinking water.
Authors: Holm A.McR. , Payne AL , Morgan PD , Speijers EJ
Published: December 2005

The study was designed to evaluate the effects of phosphorus and non protein nitrogen supplementation on weaner cattle grazing natural pastures on the Fitzroy Pastoral Research Station, north Western Australia. The study was repeated over the period July 1971 to April 1976, with four drafts of weaners which grazed Mitchell grass pastures during the dry season and curly spinifex-ribbon grass pastures during the wet season. In each year, one of four groups received either no supplement (control), urea plus sulphuric acid, phosphoric acid, or urea plus ammonium sulphate plus phosphoric acid. The supplements were measured into and mixed with the drinking water. Weaners given phosphoric acid gained between 10.5 and 21.7 kg a head more than those not given phosphorus. The response was significant in two of the four dry seasons, three of the four wet seasons and for every ye= when both seasons were considered together. Urea supplements increased liveweight gain over the dry season and depressed liveweight gain over the wet season. There was no advantage to urea when the two seasons were combined. Cattle given supplements through the drinking water drank less water and more of those given nitrogenous compounds died than those not receiving supplements.
Pressures for competing uses of the north west pastoral lands of Australia.
Authors: Young MD
Published: December 2005

of investigations by C.S.I.R. on the control of galvanised burr, Bassia birchii F. Muell., during the period 1936-46 and general discussion of control of this weed. C.S.I.R. Brisbane, unpublished report. (Manuscript received 28 October 198 1) Aust. Rangel. J. 3(2) 1981, 149-60. PRESSURES FOR COMPETING USES OF THE NORTH WEST PASTORAL LANDS OF AUSTRALIA M.D. Young CSIRO Divisionof Land Resources Management, Deniliquin, N.S. W. 2 71 0. Abstract Some Aboriginal, conservationist, mining and urban people are placing pressures on politicians and administrators to alter the nature and extent of land use in northern Australia. This paper identu3es some of the legislative and administrative changes which could arise from these and future pressures. Consideration is given to pastoralists' political strength, the growth of the mining and tourist industries, possible changes in the position of Aboriginals and possible changes in the grazing rights of pastoralists. It is suggested that in the future more people will attempt to influence the way pastoral lands are used and that increased demands for the more conservative land use practices and livestock management techniques will constrain pastoralists' activities.
Changes in tiller and tussock characteristics of Astrebla lappacea (curly Mitchell grass) after burning.
Authors: Scanlan JC
Published: December 2005

Tiller and tussock characteristics of Astrebla lappacea (curly Mitchell grass) were studied at nine locations burnt by wildfires in north-west Queensland. Tussock number increased after burning although basal area was not affected. New tiller number (per quadrat) was not related to either tussock basal area or post-fire rainfall on burnt plots. Production of new tillers in unburnt plots was inversely related to the number of old tillers. New and old tiller weights were negatively related to tiller number per unit basal area. New tillers from burnt plots had higher 1eaf:stem ratios than new tillers and axillary shoots from old tillers in the unburnt plots. Dry matter production, two years after burning, was similar in burnt and unburnt plots despite the presence of more old tillers and fewer new tillers in the areas burnt by wildfires. Most tillers died within three years of being produced.
Seasonal variations in the herbage mass, crude protein and in-vitro digestibility of native perennial grasses on the north-west slopes of New South Wales.
Authors: Lodge GM , Whalley RDB
Published: December 2005

Seasonal variations in herbage mass, crude protein content and in-vitro organic matter digestibility of both the warm-season (summer-growing) native perennial grasses, Aristida mrnosa R.Br., Bothriochloa macra (Steud) S.T. Blake, Dichanthium sericeum R.Br. (Camus), Sporobolus elongatus RBI., Chloris truncata R.Br. and Eragrostis leptostachya Steud, and the year-long-green perennial grasses Stipa variabilis Hughes and Danthonia linkii Kunth were investigated at three sites on the North-West Slopes of New South Wales. These preliminary data were used to assess the relative grazing value of the dominant grasses in the region, although these initial rankings can only be confirmed by diet selection and animal production studies. The eight grasses tested were classified into three groups with respect to their green leaf mass per unit basal area throughout the year: (i) Aristida ramosa, Bothriochloa macra, Dichanthium sericeum and Sporobolus elongatus had low amounts of green leaf in winter and their green leaf mass in summer was related to rainfall. (ii) Chloris truncata and Eragrostis leptostachya showed considerably less seasonal variation in the amount of green leaf and had a higher percentage of green leaf than (i). (iii) Stipa variabilis and Danthonia linkii had the lowest variation in green leaf, and in winter and spring they generally had higher green leaf masses than the other groups. Among the warm-season and year-long-green grasses the green leaf crude protein content varied between 5 and 15% throughout summer and autumn and from 6 to 17% in winter and spring. In all seasons dead leaf crude protein contents were around 5% and dead stem crude protein contents were consistently less than 6%. Irrespective of species the digestibilities of the green leaf portions were higher in spring and summer (60 to 80%) than in autumn and winter (50 to 60%). At each of the ~ites the digestibility ofDanthonia linkii green leaf material was generally higher than 60% in all seasons, but that ofStipa variabilis green leaf was always less than 60%. Estimates of green stem digestibility ranged from as low as 25% for Avistida ramosa in autumn to around 60% for most other species in spring. Digestibilities of dead leaf ranged from 30 to 55%, those of dead stem ranged from 20 to 40%. These results indicate that Danthonia linkii is potentially valuable for grazing and that Aristida ramosa is an undesirable pasture species. Of the other grasses tested Chloris truncata and Eragrostis leptostachya may produce some green forage in autumn and winter but at these times the green forage production of Aristida ramosa, Bothriochloa macra, Dichanthium sericeum and Sporobolus elon- gatus is limited by low temperatures.
The feasibility of farming kangaroos.
Authors: Shepherd NC
Published: December 2005

The possibility of farming kangaroos for profit has generated interest for more than a decade. This article discusses aspects of
kangaroo biology and husbandry, markets for kangaroo products, and some legal and administrative matters that could affect a kangaroo
farming enterprise.
Production under intensive conditions is limited by a low reproduction rate and a slow growth rate. Handling difficulties would
also ensure many husbandry problems. Rangeland farming of kangaroos is limited by the mobility of kangaroos, their ability to jump
stock fences and behaviour patterns which prevent mustering or herding.
Markets for meat and skins are limited and are adequately supplied from the existing rangeland harvest (i.e. kangaroo hunting).
Farmed kangaroos could not compete successfully in these circumstances because of high costs associated with establishing and
operating a kangaroo farming enterprise. The conclusion is that kangaroo farming is not a feasible proposition at this time.
Production characteristics of an open range cattle herd in South-East Pilbara region of Western Australia.
Authors: Gardiner HG , Shackleton KR , Morrissey JG
Published: December 2005

Production and management characteristics of an open range shorthorn beef cattle herd were recorded for a four year period on a cattle station in the south-east Pilbara region of Western Australia. Herd numbers increased from 893 to 1538 resulting in a 72% increase in grazing pressure on the grazeable portion of the lease. Branding rates varied from 54 to 78% of the cows present for mating the previous year. Mortality rates increased from 4% in 1974 to 15% in 1976. Losses anlong cows older than six years and female calves were significantly higher than among animals in other age and sex categories. Turnoff during this period of herd build-up varied from 3 to 11% of the herd.
Productivity and management of western Queensland's rangelands.
Authors: Pressland AJ
Published: December 2005

This article provides a brief description of the environment of western Queensland, and details of management practices employed
by graziers to economically produce meat and wool.
Changes in pasture composition occasioned by grazing pressure and difference? in annual rainfall are given. Whereas Mitchell
grasslands are stable, and only affected in the short-term by the usual vagaries ofweather and stock-imposed stres?, mulga rangelands
are unstable, and in a continual state of flux. Stock management, timber density and weather are each, separately or combined, liable
to effect changes in floristics and consequently in animal productivity.
While Mitchell grass and mulga rangelands together cotnprise the bulk of Queensland rangelands, other rangelands are also
discussed including those dominated by spinifex, eucalypt woodlands, gidgee and chenopod shrublands.
Points of reference in the assessment of change in vegetation and land condition.
Authors: Wilson AD
Published: December 2005

An analysis is made of the selection and application of reference areas in the derivation of indices of range condition. In present
usage there are deficiencies arising from bias in reference area selection, the absence of correction for natural variation, the designation
of 'climax' as 'best' and the choice of grazing pressure as the only gradient of vegetation change.
A system of nlultiple reference areas is proposed, based on a sampling of land units and the analysis of the principle vectors contributing
to vegetation change. These areas would be chosen ;IS a statisticai sample of the land unit they represent and the calculation
of indices of difference or change would be corrected for errors arising from natural variatio~i and measurement error. Reference areas
would be chosen on the basis of their potential productivity in terms of the principal land use.
A simple single disc pitting and seeding machine for arid rangeland revegetation.
Authors: Gintzburger GA , Skinner PW
Published: December 2005

A simple, single disc, pitting and seeding machine was developed for revegetation operations on degraded arid rangelands. This machine creates a shallow pit in which seeds or medic burrs are dropped and rainwater is trappedThe length or depth of a pit can be altered by changing the disc shape. The machine consists of a seed box and a single modified plough disc, articulated behind a two- wheeled trailer. The disc directly activates the seed or burr dispenser. The machine operates behind a car. The low-cost machine could be an attractive option for rangeland revegetation programmes on privately-run Australian pastoral properties or rangelands of develop- ing countries.
Research aspects of the human ecology of settlement in the Australian arid zone.
Authors: Parkes D
Published: December 2005

The Australian arid lands carry a population of about 500,000 residents and a further 250,000 periodic visitors, mainly tourists. This paper introduces concepts and principles from the field of human ecology and proposes that there may be some advantages in adopting an ecological approach to the study of human settlement in the Australian arid lands, where stressed environment and remote- ness play such an important part in human behaviour. Human ecology has been a branch of humangeography for more than 60 years. Some new interest has developed in the ecological approach because of recent advances in the understanding of the role of time as a space structuring factor.
Pastoral land tenure options in Australia.
Authors: Young MD
Published: December 2005

Most pastoral land in Australia is leased under a form of perpetual or term lease. Covenants are attached to these leases in an attempt to achieve various social, economic and environmental objectives. Land tenure options necessary to achieve these objectives are identified and contrasted with the current tenure systems. From an administrative and management viewpoint each tenure system has a number of strengths and deficiencies. The necessary characteristics of a tenure system which retains the strengths and overcomes the identified deficiencies are outlined.
The effect of different pasture management strategies in north-west Queensland on liveweight gain and wool growth rate of several groups of young sheep.
Authors: Stephenson RGA , Pritchard DA , Pepper PM , Connelly PT
Published: December 2005

The effect of three different pasture management strategies on liveweight gain and wool growth rate of young(weaner) sheep was examined immediately after weaning on Mitchell grass-Flinders grass pastures during the dry season of north-west Queensland. The pasture management strategies were designed to mimic various industry situations, while the performance of four different progeny groups was compared and used to provide an overall assessment of pasture quality.

Pasture treatments (experiment 1) consisted of three paddocks, a harvested (c. 8% of pasture harvested and baled) and spelled, a spelled, and a continuously grazed paddock. Spelled paddocks were not grazed during and after the wet season for a period of six months while the continuously grazed paddock was continuously stocked before the experiment. Experiment 2 consisted of spelled and continuously grazed paddocks. Pastures were evaluated by measuring the changes in composition and quality (experiment 1) and the responses in liveweight gain (experiments 1 and 2) and wool growth of the weaners (experiment 1). Marked improvements (c. 100%) in weaner growth rates occurred in the spelled paddocks. Greasy wool production by three groups of ewes in experiment I was about 14% greater in the harvested paddock than in the others.

At the start of the trial there were no significant differences in dry matter yield but a significant difference in botanical composition occurred between paddocks. The changes in dry matter that occurred between the beginning and end of grazing were not significantly different between paddocks. Before gazing, forbs made up approximately 16%, 4% and 1% of pastures in harvested, spelled and continuously grazed paddocks respectively. The change in the percentage forbs that occurred between the beginning and end of the grazing period was significantly greater in the harvested paddock than in the other paddocks indicating preferential selection and intake by sheep. The differences in weaner live weight and wool growth between paddocks suggest that paddock management can improve weaner productivity. The study also indicates that paddock management could be successfully used to increase the percentage of forbs and quality of the pasture during the dry season. The superior wool growth of two progeny groups also suggests that improved productivity of breeding flocks in the tropics is possible if superior sheep can be identified. The results highlight the importance of preferential management of pasture for weaners so that productivity advantages can be exploited.
Preliminary observations on the effect of removal of black bluebush (Maireana pyramidata) and Pearl Bluebush (M. sedifolia) on shrub regeneration, herbage production and erosion potential.
Authors: Tupper GJ , Muller WJ
Published: December 2005

The effects of mechanical removal of shrub tops and grazing on two bluebush communities, one with Maireana pyramidata (black bluebush)and the other with M. pyramidata and M. sedifolia (pearl bluebush) as co-dominants, were examined on the western edge of the Riverine Plain in New South Wales Measurements were made on shrub regeneration, the relationship of shrub units to a critical value for an erosion index, the change in soil surface levels, and the growth of herbaceous plants over time

Shrub regeneration was slower under grazed than ungrazed conditions and occurred mainly from basal shoots of established plants rather than from seedling establishment. Herbage yields Increased on the mounds previously occupied by shrubs, whereas production between shrubs was not affected by shrub removal.

After four years there was sufficient shrub growth to prevent wind erosion, except on the cleared and grazed plot at the M. sedifolia site.
The pasture dynamics and management of two rangeland communities in the Victoria River District of the Northern Territory.
Authors: Foran BD , Bastin G , Hill B
Published: December 2005

The use of destocking as a means of promoting pasture recovery was evaluated on two important rangeland types of the semi-arid tropics of north west Australia. Recovery on eroded calcareous red soils was substantial within five years. Standing biomass and species composition, particularly the contribution of the major forage grass Enneapogon spp., was then similar to areas in good condition. However, an exotic shrub, Calotropls procera, invaded the area during the study.

Grazing limited its increase to 200 bushes ha-1 compared to unstocked areas where it increased to 1,000 bushes ha-1. Destocking had no effect on cracking clay soils in good condition, dominated by Chrysopogon fallax and Iseilema fragile. An index based on similarity measures of herbage standing biomass, followed closely the course of recovery of the eroded calcareous soil during the period. There is a need for range condition assessment and the development and application of appropriate pasture management strategies for the whole district.
Effectiveness and economics of destruction of rabbit warrens in sandy soils by ripping.
Authors: Wood DH
Published: December 2005

The practicability and success of reducing rabbit numbers in a sand-dune habitat in which they survive droughts, by destroyingtheir warrens using a hy- draulically operated ripper mounted on a relatively light-weight wheeled tractor, was examined in a 47 km paddock on a sheep-grazing property in far north- western New South Wales. During the two year experimental period the number of warrens with more than four open holes in the treated area fell from 294to 39 whilethe number in the untreated area varied between 348 and 400. Small warrens with four holes or fewer were not ripped. Their numbers in the treated area increased from 183 to 194 compared with 384 to 406 in the untreated area. However, in the treated area, more increased in size to become large warrens and more new ones were dug than in the untreated area. The total number of active holes, an index of rabbit numbers, fell on the treated area from 3,122 to 397.56% of those remainingoccurred in the unripped small warrens. In the untreated area the number of active holes fell from 3,622 to 3,073. The results show that ripping warrens with a small wheeled tractor is an effective technique for reducing rabbit numbers in sand-dune"survival"areas. Ef- fectiveness is dependent on the ripping programme operating over a series of years with follow-up re-ripping. Missed small warrens can be a source of reinfesta- tion. Examination of the economics of such a programme indicated that the expense of ripping would be more than covered by the returns from increased wool production which might be expected with the reduction in the number of rabbits and by various tax benefits flowing from the
The population structure and density of central Australian trees and shrubs, and relationships to range condition, rabbit abundance and soil.
Authors: Friedel MH
Published: December 2005

The regional variation in population structure and density of trees and shrubs was investigated in four central Australian pasture types: open woodland, mulga annual, calcareous shrubby grassland and bluebush nse. The possible influences of range condition, rabbit abundance, soil erosion and so11 characteristics were examined, and the likelihood of long-term change was cons~dered. Density at some woodland and mulga sites was potentially high enough to depress pasture yield. The most common "increaser"species were Casszaspp. in open woodland and mulga (Acaciaaneura) in mulga annual. None of the measured influences related closely to population structure and density, and it is argued that changed fire regimes are most likely to have led to increasing densities of trees and shrubs. Density in calcareous shrubby grasslands was related to rabbit abundance, and smaller size classes of trees and shrubs were severely depleted whererab- bits were plentiful. Continuing loss of the woody plant resource is forecast, if rabbits are not controlled. Other measured influences were not related to woody plant population characteristics. Bluebush (Maireana miroiricha) populations were considered to be relatively stable under current management of bluebush rises.
The growth and survival of young Mulga (Acacia aneura F. Muell) trees under different levels of grazing.
Authors: Brown RF
Published: December 2005

The effects on the survival and growth of young mulga trees exposed to five levels of sheep graztng were monitored over bur years. The levels ranged
from complete exclusion of domest~c stock to continuous grazing at a projected annual consumption rate of 20%, 35%, 50%, or 80% of the total available
forage (grass, herbage, and accessible mulga leaf).
Innially, all trees were less than 90 cm tall. Four years later, the ungrazed trees had more than doubled in he~ght whereas thegrazed trees were not significantly
taller, irrespective of grazing intensity. Over 90% of the ungrazed trees had grown above the upper limit of sheep browsing (I20 cm) and their growth
was considered unlikely to be prejudiced by subsequent grazing. Stem diameters nearly trebled in ungrazed mulga but much smaller Increases (averagmg25%)
occurred in grazed plants.
Overall, 36% of the young trees died. Most deaths occurred during the winter of 1980 and summer of 1982183 after protracted periods of dry weather.
Grazing had little or no e,ffect on death rates.
Even the lightest grazing arrested mulga growth and prevented the transition from low mulga to the tailer forms used for drought feeding. This is discussed
as a possible cause of reported declines in drought reserves of mulga. The results of this study illustrate the need to ensure that grazing strategy is compatible
with uninterrupted replacement of umbrella mulga (5-8 m high) cut for drought fodder.
Effect of grazing on chemical and physical properties of an earthy sand in the Western Australian Mulga Zone
Authors: Hacker RB
Published: December 2005

An earthy sand supporting a mulga shrubland community in the arid winter rainfall zone in Western Australia is characterized in terms of its chemical and physical properties. In this study, changes in these properties with overgrazing were investigated.
Nutrient levels were low in relation to some soils supporting mulga communities elsewhere in Australia. Marked accumulations of total N, organic C and exchangeable Ca occurred in the hummocks of wind blown material surrounding surface obstructions. Improved water relationships are probably responsible for the abundance of ephemeral growth on such areas, and for their subsequent chemical enrichment. Changes in chemical properties with depth were evident for pH, total N, organic C, available P and exchangeable Mg with values decreasing from the 0-2 cm layer to the 2-10 cm layer in all cases.
Chemical changes associated with overgrazing were restricted to the 0-2 cm layer. Some trends towards lower levels of organic C, total N, and available P could be distinguished, particularly for organic C and total N in hummock surfaces, but chemical parameters generally did not provide a sensitive measure of grazing impact.
Sorptivity varied between the sandy and crusted phases of the soil mosaic and was reduced on sites in very poor condition. Sorptivity changes under grazing were apparently mediated partly by changes in the structural properties of the soil crust. There was no significant effect of overgrazing on either the bulk density of the surface (sub-crust) soil or on summer surface temperatures.
A Comparative Study of Sheep Grazing a Semi-Arid Saltbush Pasture in Two Condition Classes.
Authors: Graetz RD
Published: December 2005

Measurements were made of the wool growth, body weight gain and diet of sheep grazing a saltbush pasture near Broken Hill, N.S.W.
The experiment utilized a fenceline contrast in saltbush (Atriplex vesrcarra) density that was visible on Landsat imagery. It ran for five years
(1976-1981) with a design of two pasture types by two stocking rates. Fleece weights varied from 3.9-6.0 kg/head and wool production from
0.6-2.9 kg/ha. Neither wool production per head nor bodyweight were substantially affected by stocking rate or pasture type. The composition
and quality of the diets selected by sheep on both pastures were identical and of high nutritional value indicating their capability to accommodate
differences in pasture composition. Pasture quality was not limiting between stocking rates or determined by the abundance of saltbush.
Changes in pasture composition resulting from grazing and exclosure were small and of no significance.
The Composition of Phytobezoars (Felt Balls) from Sheep in Western Australia.
Authors: Blackshaw DD , Oliver AJ
Published: December 2005

Bezoars (felt balls) from sheep on Jeedamya and Adelong stations north of Kalgoorlie, and on a farm near York, Western Australia, were examined microscopically and found to consist principally of a dense mass of sclerenchyme fibres. In size, colour and texture the bezoars closely resemble bezoars composed of plant epidermal hairs, described by South African workers. Acacra ramulosa is suggested as the likely source of bezoar fibres at Jeedamya and Adelong. The source of fibres from York was not determined. The identification of plant species from which bezoar fibres are derived may make possible the control of bezoariasis by grazing management.
Sediment Yield in the Barrier Range Before and After European Settlement.
Authors: Wasson RJ , Galloway RW
Published: December 2005

Sediment yield has been estimated for the catchment of Umberumberka Creek, just west of Broken Hill in far western New South
Wales, for two periods before European settlement and for three periods after settlement. The approach is stratigraphic whereby pre-settlement
yields have been estimated from a radiocarbon-dated alluvial fan while post-settlement yields have been calculated from surveys of sedimentation
in Umberumberka Reservoir. The average post-settlement yield of 1.9 m3 ha-' yr-' is about 50 times greater than the average yield
for the 3000 years preceding settlement. The highest recorded post-settlement yield of 3.1 m3 ha-' yr-', over the interval 1915-1941, is
about 90 times greater. Sediment yield in the interval 3000 to 6000 years BP was higher than in the interval 3000 years BP to European
settlement but lower than the post-settlement yield. Changes of sedimentation rate have been detected in the reservoir since it was built in
1915, reflecting variations in the delivery of sediment to the streams and storage of sediment within the catchment. The nature of these mechanisms
has not been accurately determined but comparison of sedimentation rates in reservoirs in south-eastern Australia suggests that a regional
increase in rainfall during this century has played a role. If this is correct then the reduced sediment yields since the 1940s are no more
than partially related to management and the reduction of rabbits.
Land Use in Australia's Rangelands.
Authors: Young MD , Walker PA , Cocks KD
Published: December 2005

Arguments for or against the re-allocation of land in Australia's rangelands from one use to another are frequently short on data
and long on emotion. Although data presented in this paper are not sufficient to resolve these arguments, they do suggest some options
for closer examination.Starting from a model for calculating viability prospects for pastoralism in the rangelands, the paper examines the
extent of grazing and the pastoral viability prospects for the areas devoted to each of the major land uses. Possibilities for changes in use
in each of the states are also described.
Analysis of historical records of a grazing property in south-western Queensland. 2. Vegetation changes.
Authors: Oxley RE
Published: December 2005

This article combines data from historical records, recently published maps and a field survey to document changes in the vegetation of a pastoral
area in south-western Queensland. Examples are given where wildfire, ringbarking,clearing and grazing by both rabbits anddomestic stock have had
major influences on the vegetation.
The greatest change to the trees and inedible shrubs has been one of density. Evidence for changes in the herbaceous layer is less conclusive but it
is likely that there has been a reduction in density of desirable perennial grasses and an increase in less palatable species.
Effect of drought and high summer rainfall on biomass and comsumption of grazed pastures in western New South Wales.
Authors: Robertson G
Published: December 2005

The biomass and composition of grazed pastures near Menindee, in westem New South wales, were estimated over a range of seasonal condilions between 1980 and 1985. Differences in biomass and composition of pastures grazed separately by kangaroos and by a mixture of sheep and kangaroos were minor. Pasture biomass ranged from 7 kgha during a drought to 1,100 kgha following high summer rainfall. Overall, biomass average 374 kgha with a slandard deviation among years of 302 kgha. Pasture biomass fluctuated markedly among calendar seasons and years in response to erratic rainfall and grazing. I-Iigh summer rainfall triggered a switch in pasture dominatnace from annuals to shoa-lived perennials.
The cage method of sampling to assess herbage mass and herbage consumed on annual rangeland vegetation
Authors: Zahran BB , Holm AM , Stern WR , Loneragan WA
Published: December 2005

The cage method of sampling vegetation was used to estimate herbage mass and herbage consumed by sheep, grazing a pasture dominated by annual species, near Camawon, Western Australia. Using paired quadrats (2m x lm), one caged and the other open, herbage mass and herbage consumed were measured at five stocking rates on two soil types, on eight occasions between December 1983 and January 1985. The data were highly variable; nevertheless, some effects of season, soil type and stocking rate could be observed. The results showed clear seasonal trends. Some soil type x stocking rate interactions were detected during the dry periods of the year when herbage mass was low. Generally, the cage method tended to over-estimate herbage consuped. Sheep consumed approximately 119 to 116 of the available herbage at low and high stocking rates respectively when feed was plentiful; when feed was in short supply the corresponding figures were approximately 113 and 1/2. The limitations of the method are discussed and some suggestions made concerning its applicability in rangeland studies.
Daily trapping of sheep at a watering point: A technique for animal nutrition studies under field conditions.
Authors: Stephenson RGA , McKenna DG , Connelly PT
Published: December 2005

Animal nutrition studies require large resource outlays for paddock and treatment replication to ensure treatment outcomes are valid. In addition to paddock variations there can be large variations in supplement intake if voluntary feeding is paxt of a treatment. To overcome these problems, a technique for trapping grazing sheep at the watering point each day was investigated. Two studies were conducted under dry seasonal conditions, one using pregnant ewes, the other using wethers. Two other studies were conducted under more favourable green pasture conditions, again with pregnant ewes and wethers. In each study, the sheep were educated to enter the yard surrounding the water trough through a trap consisting of two weldmesh panels, each 2m in length. Lucerne hay was used in the first week to coax the sheep between the panels and into the yard. After the education period, treatments were administered to sheep within a race inside the trap yard. In one dry season study some sheep were returning to the trap yard six to eight hours after release. A standard alarm clock was then installed to open this trap at 6.00 a.m., two to three hours before treatments were administered. This procedure was successful in that all sheep continued to be trapped. More than 98% of the sheep were trapped over the treatment period in both dry season studies. However, under green pasture conditions an average of 86% of pregnant ewes and <50% of wethers were trapped. Aversion to the treatments applied in the latter study may have been partly responsible for the poor trapping result which had followed a successful education period. Trapping during dry seasonal conditions offers several advantages for grazing experimentation.
Soil surface features as indicators of rangeland site productivity.
Authors: Tongway DJ , Smith EL
Published: December 2005

Criteria for the classification of Red Earth soils into groups reflecting differences in their productive potenrial were investigated on three sites near Cobar, New South Wales. Five features were shown to be useful by cluster and discriminate analysis of an extensive data set. A field-based classification using six very similar criteria was also tested and shown to agree with the cluster method. Laboratory tests for stability and fertility of the surface soil layer from each class indicated a significant difference between classes, and a narrow range of values for an individual class. Herbage production on quadrats over the range of soil surface condition also consistently reflected the classification. When the method was tested with three personnel previously unfamiliar with the criteria, good agreement with the original experimental set was obtained.
The effect of ant activity on meat baits impregnated with sodium monofluoroacetate (Compound 1080) used for the control of dingoes and wild dogs.
Authors: Merks PF , Calver MC
Published: December 2005

Wild dog and dingo baits impregnated with the toxin 1080 and exposed at two different sites in the field suffered significant reductions in weight compared with controls as a result of ant activity. In one case a bait was completely destroyed in five days, while others were reduced in weight by over 70% during the same period. Sun-drying of baits for 48h before laying did not significantly reduce damage by ants. Ant activity may detoxify baits before they are taken by wild dogs.
Seedling emergence of hummock grasses in relation to the effects of fire.
Authors: Bogusiak A , Rice B , Westoby M , Friedel MH
Published: December 2005

The ecology of hummock-grass vegetation involves recurring fires. The hypothesis was tested that soil seed banks of hummock grass species are stimulated to germinate by the heat of fire or by ash addition. Hummocks of Plectrachne schinzii Henr., Triodia basedowii E. Pritz., and Triodia pungens R. Br. were burned, removed, or removed with the ash returned, and subsequent regeneration was recorded, in Ulum National Park. Regeneration of hummock grass was by seedlings only. Seedling emergence averaged 5/m2, with no differences between treatments or hummock grass species. This indicates the heat of fires and ash addition may not be important in stimulating seed germination of these hummock grass populations. Gemination was distributed over more than one rainfall event following the treatments.
Should rangeland rehabilitation be paid for from the public purse?
Authors: Lindner RK
Published: December 2005

The issue addressed in this paper is the appropriate source of funding for rangeland rehabilitation. Two subsidmy questions are pertinent to this policy issue. Is it profitable for private managers of pastoral properties to rehabilitate rangeland? If not, then on what grounds might it be in the public interest to do so? Evidence is presented that it is privately profitable to rehabilitate slightly to moderately degraded range, by destocking during seasons when there are good prospects for seedlings to become established, but otherwise matching the stocking rate to feed availability. Conversely, it is unprofitable to rehabilitate severely degraded range unless the cost of reseeding is subsidized by at least $5/ha. The relevance of various market failure arguments to the case for public fun- of rangeland rehabilitation to the extent of $100million is discussed, and the need to estimate the existence value of rangelands vis a vis other conservation goals is identified.
The use of radio transmitters for tracking and shooting feral buffalo.
Authors: Carrick P , Thomson D , Calley G
Published: December 2005

An exercise is described in which transmitters were attached to feral buffalo females and these 'judas cows' were then used to lead a shooter to other animals with which they sought company. The technique, the problems and the benefits are described. The efficiency and thoroughness with which feral buffalo can be shot in difficult country is greatly increased by the use of radio tracking. The use of the technique with other feral animals in northern Australia or in extensive buffalo or cattle husbandry is discussed.