Measuring and predicting the consequences of drought for a range of perennial grasses on the Northern Tablelands of New South Wales

2000 ◽  
Vol 40 (2) ◽  
pp. 285 ◽  
Author(s):  
S. P. Boschma ◽  
J. M. Scott
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
New South ◽  
New South Wales ◽  
Perennial Grasses ◽  
Severe Drought ◽  
Plant Mortality ◽  
Wool Growth ◽  
South Wales ◽  
Drought Conditions

An experiment was conducted at Armidale, New South Wales to evaluate the persistence and productivity of 6 perennial grasses under 2 defoliation severities and a range of moisture/drought conditions created using a rain-out shelter. Defoliation was either moderate or severe whilst the moisture/drought conditions imposed included a non-stressed moisture treatment, and seasonal droughts simulated as 40-percentile (40-P) and 10-percentile rainfall (10-P). The treatments were applied over 2 experimental seasons; spring–summer and summer–autumn. A range of measurements was taken including plant mortality, basal area, foliage greenness, herbage mass, growth rate and digestibility. Some of these results were then used as inputs to the GrazFeed decision support system to predict liveweight gain and wool growth rate from pastures growing under such conditions. Plant mortality of over 40% was observed in Dactylis glomerata and Lolium perenne under moderate (40-P) drought conditions during spring–summer. In contrast, under severe drought conditions (10-P), less than 20% of plants died, suggesting that, when combined with defoliation stress, a more common drought can present a greater hazard to plant persistence than a severe drought during spring–summer. Plant mortality was reduced and non-significant when subjected to the summer–autumn drought treatments. Plant growth and predictions of animal productivity varied widely among the species challenged with drought and defoliation stresses. Predicted liveweight gains of weaner sheep under severe drought conditions (10-P) varied between species ranging from 20 to 110 g/day. Under the same conditions, predicted wool growth rates varied between species from 5 to 11 g/wether. day, while pasture growth rates varied from a low of 0 to more than 120 kg DM/ha. day. The animal effects were due largely to differences in herbage mass and the degree to which the grass remained green. These results highlight the importance of maintaining the most productive species in pastures through drought.

Performance of temperate legumes and associated grasses on granitic soils of low fertility in the New England region of New South Wales

1975 ◽  
Vol 15 (77) ◽  
pp. 795 ◽  
Author(s):  
JA Thompson
Keyword(s):  
New England ◽  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Fertilizer Application ◽  
Perennial Grasses ◽  
Low Fertility ◽  
South Wales ◽  
Applied Nitrogen

A range of temperate annual and perennial legumes, naturalized or commonly sown in the area, was examined at three field sites in low fertility soils derived from granite on the south western slopes of the New England Region, New South Wales. They were compared over a four year period in terms of their persistence, dry matter and nitrogen production and their compatibility with associated temperate perennial grasses, The response of sown grass to nitrogen fertilizer application was also examined in the absence of legume. Ten legumes were examined at one site and six of these at the other two sites. In general, nitrogen yields were ranked similarly to total dry matter yields of all treatments, including grasses in the absence of legume. However, the legumes were ranked differently in terms of productivity of the legume component and productivity of associated grass. At all sites lucerne gave the highest yields of total dry matter and of legume and the lowest yield and persistence of associated grass-comparable to grass growing in the absence of legume or applied nitrogen. Subterranean clover was ranked second or third in total dry matter yield, depending on site, but provided the highest yield of associated grasscomparable to grass receiving high levels of applied nitrogen. Under this legume soil nitrogen levels tended to be highest. Rose clover, sown at one site only, yielded more legume dry matter than subterranean clover but grass yield was comparable to that with lucerne. The results suggest that subterranean clover is the superior legume for successful mixed sowings although inclusion of white clover could be justified. Lucerne appears to be best sown as a pure sward.

Seasonal Changes in Diet Preferences of Free-Ranging Red Kangaroos, Euros and Sheep in Western New South Wales.

1977 ◽  
Vol 4 (2) ◽  
pp. 127 ◽  
Author(s):  
BA Ellis ◽  
EM Russell ◽  
TJ Dawson ◽  
CJF Harrop
Keyword(s):  
Animal Species ◽  
New South ◽  
New South Wales ◽  
Stomach Contents ◽  
Ovis Aries ◽  
Severe Drought ◽  
Red Kangaroo ◽  
South Wales ◽  
Selective Eating ◽  
Free Ranging

Stomach contents of free-ranging animals were analysed botanically for low Atriplex shrubland in western New South Wales, Australia, during 1972-74 in good seasons producing abundant growth and diversity of vegetation. Red kangaroo (Megaleia rufa), euro (Macropus robustus) and sheep (Ovis aries) selected grass and forbs when those were readily available. In poorer pasture sheep selected mainly flat-leaved chenopods (saltbush) and kangaroos selected mainly grass with different amounts of flat- or round-leaved chenopods. Euros were the most selective, eating grass even when there was little grass present. Potential overlaps in diet between kangaroos and sheep were greatest in good pasture and least in the poorest conditions. The other groups of plants considered were non-chenopod shrubs and browse. Extent of overlap was not clear, because animals may have eaten different species within the groups of plants. The study period did not include any severe drought, in which overlap in diet and competition between animal species would have been most significant.

The growth rates of weaned lambs grazing three legume-based pastures during summer

1980 ◽  
Vol 20 (102) ◽  
pp. 9
Author(s):  
ID Sanderson ◽  
JD McFarlane ◽  
WR McManus
Keyword(s):  
Growth Rates ◽  
New South ◽  
New South Wales ◽  
Red Clover ◽  
Experimental Period ◽  
Poor Growth ◽  
Average Growth ◽  
The Poor ◽  
South Wales ◽  
Lamb Growth

An experiment was conducted on the Central Western Slopes of New South Wales with Dorset Horn x Merino lambs to assess their liveweight gains during summer when weaned on to a lucernebased pasture under dryland conditions, and when weaned on to irrigated lucerne and red clover pastures. Lambs grazing irrigated lucerne, irrigated red clover and dryland lucerne had average growth rates of 155, 178 and 124 g day-1/head, respectively, throughout the 106 day experimental period. The poor growth rates of lambs on the dryland lucerne were apparently due mainly to the low digestibility of the dry feed on offer as a result of low rainfall, which also caused feed supply to be limiting during part of the experimental period. Lamb growth and intake data suggest that the diets selected from the red clover were of higher digestibility than those selected from the irrigated lucerne. It was concluded that irrigated red clover and irrigated lucerne provided useful diets for young lambs in this environment, although the growth rates achieved were less than reported elsewhere for these species in cooler climates. Growth rates achieved by lambs grazing dryland lucerne were less satisfactory for prime lamb production.

Establishment of Warm- and Cool-Season Native Perennial Grasses on the North-West Slopes of New South Wales. Ii. Establishment and Seedling Survival in the Field

1981 ◽  
Vol 29 (2) ◽  
pp. 121 ◽  
Author(s):  
GM Lodge
Keyword(s):  
New South ◽  
New South Wales ◽  
Warm Season ◽  
Perennial Grasses ◽  
Late Winter ◽  
Cool Season ◽  
North West ◽  
The North ◽  
South Wales ◽  
Native Pastures

Emergence and survival of the seedlings of warm-season native perennial grasses Aristida ramosa R.Br., Bothriochloa macra (Steud.) S . T. Blake, Dichanthium sericeum (R.Br.) Camus, Sporobolus elongatus R.Br., Eragvostis leptostachya Steud. and Chloris truncata R.Br. and the cool-season species Stipa variabilis Hughes and Danthonia linkii Kunth were studied in both native pastures and sown monospecific plots on the north- west slopes of New South Wales. The most favourable period for the successful emergence and establishment of warm-season grasses was from mid summer to early autumn. Cool-season native perennial grasses established best from seedlings that appeared from mid autumn to late winter. Few seedlings were observed to germinate in spring, probably as a result of large variations in temperature, low minimum temperatures or intra and interspecific competition. Seedlings growing in native pasture spent long periods in the vegetative phase compared to the early flowering of seedlings in the sown plots. In the pasture studied only two seedlings flowered over 700 days after emergence, and many others after persisting for up to 2 years died without producing seed. These findings indicate that the seedlings in these native pastures were under considerable stress and that the adult populations of the species examined were relatively stable and little recruitment occurred.

Hybrid Bermudagrass compared with Kikuyu and common couch in coastal New South Wales. 1. Establishment, dry matter production and persistence

1979 ◽  
Vol 19 (99) ◽  
pp. 437 ◽  
Author(s):  
AC Andrews ◽  
FC Crofts
Keyword(s):  
Growth Rates ◽  
Dry Matter ◽  
Cynodon Dactylon ◽  
New South ◽  
New South Wales ◽  
Sandy Soils ◽  
The Other ◽  
Potential Value ◽  
South Wales ◽  
Matter Production

Four ecotypes of hybrid Bermudagrass (Cynodon dactylon) were compared with common couch (C. dactylon) and kikuyu (Pennisetum clandestinum) at five sites in coastal districts of New South Wales. The sites were Grafton and Coaldale (Lat. 30�S), Mitchells Island (Lat. 32�S) and Richmond and Badgerys Creek (Lat. 34�S). Hybrid Bermudagrass ecotypes 6389 and 692 were established quickly at all sites while ecotypes 71 9 and 632 were satsifactory. Kikuyu was strong at all sites except Grafton but the rate of establishment of common couch was poor. At the frost-free sandy site of Mitchells Island, Bermudagrass ecotypes 719, 692, 6389, and 632 outyielded kikuyu by 75, 65, 65 and 35%, respectively. However, at Grafton and Coaldale, the highest yielding Bermudagrass ecotype, 719, had only 35% higher production than kikuyu. At the frost prone southern sites of Richmond and Badgerys Creek, the annual production of kikuyu was equal to that of ecotypes 719, 6389, 692 and 632. Common couch yields were equal to kikuyu at all sites except at Richmond. At Mitchells Island, the hybrid Bermudagrasses outyielded kikuyu in spring, summer and early autumn but in the late autumn kikuyu had equal and sometimes higher growth rates than the best Bermudagrasses. In winter, the growth of both species was negligible, although kikuyu, unlike the Bermudagrasses, did produce some new shoots at the base of the sward. Data on persistence under grazing were collected from only three of the sites but trends were similar to establishment. Ecotype 6389 had the highest persistence rating of the Bermudagrasses. Kikuyu failed at the poorly drained sandy site of Grafton but remained strong at the other sites. It was concluded that hybrid Bermudagrasses were of potential value for pastures in New South Wales, especially for sites with sandy soils and low frost incidence.

Validation of the formation and appearance of annual marks in the otoliths of yellowtail (Trachurus novaezelandiae) and blue mackerel (Scomber australasicus) in New South Wales

1999 ◽  
Vol 50 (5) ◽  
pp. 389 ◽  
Author(s):  
John Stewart ◽  
Douglas J. Ferrell ◽  
Neil L. Andrew
Keyword(s):  
Growth Rate ◽  
Age Estimation ◽  
New South ◽  
New South Wales ◽  
Early Summer ◽  
Age Class ◽  
South Wales ◽  
In Captivity

Yellowtail (Trachurus novaezelandiae) and blue mackerel (Scomber australasicus) were captured off the coast of New South Wales, marked with oxytetracycline, and kept in captivity for 1 year. The fish were periodically sampled to validate the use of their otoliths for age estimation. Opaque marks were formed during the year in the otoliths of yellowtail apparently aged 0 to 7 years and in apparently 1-year-old blue mackerel. These marks were formed in winter for both species, but did not become visible until early summer in some fish. There was an association between the growth rate of the otolith and the detection of opaque marks. Within an age class, fish with the fastest growing otoliths tended to have their most recently formed opaque marks visible earliest. These relationships between growth rate and the probability of correctly assigning an age class have important implications for ageing fish. Extra keyword: ageing

Sizes and ages in commercial landings with estimates of growth, mortality and yield per recruit of yellowtail kingfish (Seriola lalandi) from New South Wales, Australia

2004 ◽  
Vol 55 (5) ◽  
pp. 489 ◽  
Author(s):  
John Stewart ◽  
Douglas J. Ferrell ◽  
Bryan van der Walt
Keyword(s):  
Growth Rates ◽  
New South ◽  
New South Wales ◽  
Fork Length ◽  
South Wales ◽  
Current Minimum ◽  
Yellowtail Kingfish ◽  
Seriola Lalandi ◽  
Size At Age ◽  
Yield Per Recruit

The size and age compositions of yellowtail kingfish (Seriola lalandi) were studied in commercial landings in New South Wales, Australia between 1998 and 2000. The fishery was dominated by fish smaller than 65 cm fork length and these fish were estimated to be 2 and 3 year olds. Estimates of growth rates were made using size-at-age data from sectioned otoliths. The oldest yellowtail kingfish found was 21 years and measured 136 cm fork length. There were no differences in the growth rates between regions or between sexes. Yellowtail kingfish grow rapidly and reach their minimum legal length of 60 cm total length at around 2 years of age. These estimates showed that previous studies, which estimated ages using whole otoliths, may have underestimated the ages of older yellowtail kingfish. Total instantaneous mortality rates generated from catch curves ranged between 0.43 and 0.79. Yield per recruit models suggest that the population is currently growth overfished. The information provided is used to discuss the suitability of the current minimum legal length for yellowtail kingfish in New South Wales.

An experimental translocation of brush-tailed bettongs (Bettongia penicillata) to western New South Wales

2004 ◽  
Vol 31 (4) ◽  
pp. 421 ◽  
Author(s):  
David Priddel ◽  
Robert Wheeler
Keyword(s):  
New South ◽  
New South Wales ◽  
South Australia ◽  
Release Site ◽  
Severe Drought ◽  
Source Population ◽  
South Wales ◽  
Bettongia Penicillata ◽  
Radio Transmitters ◽  
Low Incidence

A total of 85 brush-tailed bettongs (Bettongia penicillata) from Western Australia and two sites in South Australia were translocated to Yathong Nature Reserve (YNR) in western New South Wales in October 2001. Aerial baiting to control the introduced red fox (Vulpes vulpes) had been undertaken on YNR since 1996. Thirty-one bettongs were fitted with radio-transmitters at the time of release, and two subsequently. Trapping took place at irregular intervals after the translocation. In all, 73% of telemetered bettongs died within the first six months; all were dead within 13 months. Eight bettongs died within the first eight days immediately following their release, due to causes other than predation. These eight all originated from St Peter Island (SPI), South Australia. A low incidence of breeding on SPI supports the belief that this source population was in poor condition and unsuited for translocation. Overall, 19 of the 33 telemetered bettongs were killed by predators: 14 (74%) by feral house cats (Felis catus), two (11%) by birds, and three (16%) by predators, which, although they could not be fully identified, were not foxes. One month after release, surviving bettongs weighed less than they did at the time of their release (mean decrease in mass = 9.7%, range 2.6–22.4%, n = 11). Within two months of their release most had regained any lost mass (mean change in mass since release = –0.3%, range –5.9 to 10.5%). Food resources on YNR appeared sufficient to sustain adult brush-tailed bettongs, despite a period of severe drought. Small pouch young present at the time of release were subsequently lost. Females gave birth and carried small pouch young (up to 50 mm), but no young-at-foot were recorded. Bettongs did not disperse further than 10 km from their release site. Overall, 50% of aerial-tracking locations were no further than 3.2 km from the release site, and 92% no further than 7.0 km. This experimental translocation of brush-tailed bettongs failed due to predation by cats. It demonstrated that foxes were no longer a threat to wildlife on YNR and identified cats as the major impediment to the restoration of locally extinct fauna.

Modelling the effect on stocking rate and lamb production of allowing ewes to graze a dual-purpose wheat crop in southern New South Wales

2014 ◽  
Vol 54 (10) ◽  
pp. 1625 ◽  
Author(s):  
S. R. McGrath ◽  
J. M. Virgona ◽  
M. A. Friend
Keyword(s):  
Growth Rates ◽  
New South ◽  
New South Wales ◽  
Wheat Crop ◽  
Stocking Rate ◽  
Gross Margin ◽  
Dual Purpose ◽  
Mixed Farming ◽  
South Wales ◽  
Gross Margins

Slow pasture growth rates during winter limit the potential gross margins from autumn and early winter lambing in southern New South Wales (NSW) by limiting stocking rates and/or increasing supplementary feed requirements. Dual-purpose crops can reduce the winter feed gap in mixed-farming systems by increasing the available feed in winter. The simulation software AusFarm was used to model a mixed-farming system at Wagga Wagga with Merino ewes joined to terminal sires and grazing lucerne-subterranean clover pasture over a 41-year period. A paddock of dual-purpose wheat was then added to the system, and ewes were allowed to graze the wheat crop when feed on offer reached 850 kg DM/ha and before GS31. Weaned lambs were sold after late August if lamb growth rates fell below 20 g/head.day, mean lamb weight reached 45 kg or production feeding of lambs was required. Lambing in June resulted in the highest median gross margin whether or not ewes were able to graze the wheat crop during winter. Grazing of a dual-purpose wheat crop resulted in greater proportional increases in gross margins as stocking rate was increased, increased lamb production and reduced supplementary feeding costs, and reduced interannual variability in gross margin returns.

Studies on Age, Growth, and Life History of the Pilchard, Sardinops neopilchardus (Steindachner), in Southern and Western Australia

1950 ◽  
Vol 1 (2) ◽  
pp. 221 ◽  
Author(s):  
JM Blackburn
Keyword(s):  
Growth Rate ◽  
Western Australia ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
The Body ◽  
Fish Length ◽  
Linear Type ◽  
Spawning Period ◽  
South Wales

The biology of the unexploited Australian pilchard, Sardinops neopilchardus (Steindachner), was studied from a limited material available from Victorian, Tasmanian, South Australian, and Western Australian waters. This completes the preliminary study of the species over almost the whole of its sub-continental range. In Victorian waters, the surface shoaling season is spring and summer, in South Australia, summer and autumn, and in southern Western Australia, autumn and winter; these are the spawning seasons for the respective areas. In New South Wales and Queensland waters, the shoaling season is autumn to spring, which is again a spawning period. The situation in Tasmania, where the species is rare, is probably similar to that in Victoria. On the west coast of Australia, where the species extends northward to the Tropic of Capricorn (as it also does in the east) the seasonal distribution is not clear. In all these areas pilchard occurrences are virtually limited to the bay and neritic waters. Victorian pilchards attain mean standard lengths of about 8.0, 10.5, 12.5, 14.0, and 15.5 cm. at the ages of one, two, three, four, and five years respectively. This growth rate is considerably lower than that in New South Wales. In southern Western Australia the growth rate is intermediate between the other two, but in South Australia it was not established. The average size of pilchards in the seasonal shoals appears to be greater in Western Australia than elsewhere, but no fish over 19.5 cm. standard length (9.0 in. total length) has been encountered in any of the current Australian investigations. Sexual maturity occurs earlier in Victoria than in New South Wales, sometimes at one year of age. The ring pattern of Australian pilchard scales is complex, involving yearly, spawning, and secondary rings. A hypothesis to account for the formation of spawning rings is outlined, and an earlier hypothesis relating to yearly rings is abandoned. Secondary rings occur on most scales from the same fish. In all waters the season of ring formation coincides with that of surface availability of fish, but in Victoria it is also the growing season, which makes age determination particularly difficult. The fish-length/scale-length relationship for Victorian material is of the same linear type as for New South Wales, but there are differences in the size of scales taken from the same area of the body. The possible influences of distribution, size, and condition of fish on future economic exploitation are discussed.

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