The limit to wheat water-use efficiency in eastern Australia. I. Gradients in the radiation environment and atmospheric demand

2007 ◽  
Vol 58 (4) ◽  
pp. 287 ◽  
Author(s):  
D. Rodriguez ◽  
V. O. Sadras
Keyword(s):  
South Australia ◽  
Vapour Pressure Deficit ◽  
Diffuse Radiation ◽  
Climatic Index ◽  
The North ◽  
South Wales ◽  
Eastern Australia ◽  
Climatic Drivers ◽  
Use Efficiency ◽  
Radiation Use

In the wheatbelt of eastern Australia, rainfall shifts from winter dominated in the south (South Australia, Victoria) to summer dominated in the north (northern New South Wales, southern Queensland). The seasonality of rainfall, together with frost risk, drives the choice of cultivar and sowing date, resulting in a flowering time between October in the south and August in the north. In eastern Australia, crops are therefore exposed to contrasting climatic conditions during the critical period around flowering, which may affect yield potential, and the efficiency in the use of water (WUE) and radiation (RUE). In this work we analysed empirical and simulated data, to identify key climatic drivers of potential water- and radiation-use efficiency, derive a simple climatic index of environmental potentiality, and provide an example of how a simple climatic index could be used to quantify the spatial and temporal variability in resource-use efficiency and potential yield in eastern Australia. Around anthesis, from Horsham to Emerald, median vapour pressure deficit (VPD) increased from 0.92 to 1.28 kPa, average temperature increased from 12.9 to 15.2°C, and the fraction of diffuse radiation (FDR) decreased from 0.61 to 0.41. These spatial gradients in climatic drivers accounted for significant gradients in modelled efficiencies: median transpiration WUE (WUEB/T) increased southwards at a rate of 2.6% per degree latitude and median RUE increased southwards at a rate of 1.1% per degree latitude. Modelled and empirical data confirmed previously established relationships between WUEB/T and VPD, and between RUE and photosynthetically active radiation (PAR) and FDR. Our analysis also revealed a non-causal inverse relationship between VPD and radiation-use efficiency, and a previously unnoticed causal positive relationship between FDR and water-use efficiency. Grain yield (range 1–7 t/ha) measured in field experiments across South Australia, New South Wales, and Queensland (n = 55) was unrelated to the photothermal quotient (Pq = PAR/T) around anthesis, but was significantly associated (r2 = 0.41, P < 0.0001) with newly developed climatic index: a normalised photothermal quotient (NPq = Pq . FDR/VPD). This highlights the importance of diffuse radiation and vapour pressure deficit as sources of variation in yield in eastern Australia. Specific experiments designed to uncouple VPD and FDR and more mechanistic crop models might be required to further disentangle the relationships between efficiencies and climate drivers.

Low rainfall rarely limits wheat yields in southern New South Wales

1989 ◽  
Vol 29 (1) ◽  
pp. 77 ◽  
Author(s):  
PS Cornish ◽  
GM Murray
Keyword(s):  
Triticum Aestivum ◽  
Water Use ◽  
Empirical Model ◽  
New South ◽  
South Australia ◽  
Wagga Wagga ◽  
Potential Yield ◽  
South Wales ◽  
Eastern Australia ◽  
Use Efficiency

Alternative models were compared for predicting the yield of wheat (Triticum aestivum) from water-use and water-use efficiency. A locally derived empirical model most closely predicted experimental yields at Wagga Wagga and was used to compute water-limited potential yields for the district surrounding Wagga Wagga for the period 1960-84. District yields were close to the predicted potential in dry years, but reached a plateau of about 2.0 t/ha regardless of rainfall and the water-limited potential yield. The yields were less than 50% of potential when water-use exceeded 300 mm, which occurred in 19 years between 1960 and 1984. Some individual farmer-yields approached the potential. These results are similar to others from South Australia. Together, they suggest that low rainfall does not directly limit yield in many years over much of the wheat belt of southern and south-eastern Australia. We suggest therefore that an analysis of the reasons for low yield on farms could lead to substantial increases in yield for many farmers.

Quantification of wheat water-use efficiency at the shire-level in Australia

2010 ◽  
Vol 61 (1) ◽  
pp. 1 ◽  
Author(s):  
A. Doherty ◽  
V. O. Sadras ◽  
D. Rodriguez ◽  
A. Potgieter
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Wheat Yield ◽  
Vapour Pressure Deficit ◽  
Diffuse Radiation ◽  
Latitudinal Gradients ◽  
Eastern Australia ◽  
Use Efficiency ◽  
Yield Formation ◽  
Seasonal Water Use

In eastern Australia, latitudinal gradients in vapour pressure deficit (VPD), mean temperature (T), photosynthetically active radiation (PAR), and fraction of diffuse radiation (FDR) around the critical stage for yield formation affect wheat yield and crop water-use efficiency (WUE = yield per unit evapotranspiration). In this paper we combine our current understanding of these climate factors aggregated in a normalised phototermal coefficient, NPq = (PAR· FDR)/(T · VPD), with a shire-level dynamic model of crop yield and water use to quantify WUE of wheat in 245 shires across Australia. Three measures of WUE were compared: WUE, the ratio of measured yield and modelled evapotranspiration; WUEVPD, i.e. WUE corrected by VPD; and WUENPq, i.e. WUE corrected by NPq. Our aim is to test the hypothesis that WUENPq suits regional comparisons better than WUE or WUEVPD. Actual median yield at the shire level (1975–2000) varied from 0.5 to 2.8 t/ha and the coefficient of variation ranged from 18 to 92%. Modelled median evapotranspiration varied from 106 to 620 mm and it accounted for 42% of the variation in yield among regions. The relationship was non-linear, and yield stabilised at ~2 t/ha for evapotranspiration above 343 mm. There were no associations between WUE and rainfall. The associations were weak (R2 = 0.09) but in the expected direction for WUEVPD, i.e. inverse with seasonal rainfall and direct with off-season rainfall, and strongest for WUENPq (R2 = 0.40).We suggest that the effects of VPD, PAR, FDR, and T, can be integrated to improve the regional quantification of WUE defined in terms of grain yield and seasonal water use.

scholarly journals Epidemiology of Bovine Ephemeral Fever in Australia 1981?1985

1987 ◽  
Vol 40 (2) ◽  
pp. 125 ◽  
Author(s):  
MF Uren ◽  
T D St George ◽  
PD Kirkland ◽  
RS Stranger ◽  
MD Murray
Keyword(s):  
Western Australia ◽  
South Australia ◽  
Viral Disease ◽  
Wave Form ◽  
The North ◽  
South Wales ◽  
Northern Half ◽  
Bovine Ephemeral Fever ◽  
Eastern Australia ◽  
Sporadic Cases

Bovine ephemeral fever is an important viral disease of cattle in Australia. The disease occurred each year, principally in summer and autumn, between 1981 and 1985. Queensland and the northern half of New South Wales were areas of greatest activity with only sporadic cases being reported from the Northern Territory and the northern third of Western Australia. Since 1981, the disease has been endemic in an extensive area of eastern Australia and has tended to occur in widely scattered outbreaks rather than the north-south advancing wave form of the epidemics of 1936-37, 1967-68, 1970-71 and 1972-74. The southernmost outbreaks between 1981 and 1985 were well within the limits of these earlier epidemics. The pattern of disease appears to have become seasonally endemic rather than periodically endemic in the northern two-thirds of eastern Australia. Ephemeral fever was not recorded in Victoria, Tasmania, South Australia or the southern part of Western Australia between 1981 and 1985

Migration and dispersal of the Rutherglen bug, Nysius vinitor Bergroth (Hemiptera: Lygaeidae), in eastern Australia

1988 ◽  
Vol 78 (3) ◽  
pp. 493-509 ◽  
Author(s):  
Garrick McDonald ◽  
Roger A. Farrow
Keyword(s):  
New South ◽  
New South Wales ◽  
South Australia ◽  
Early Spring ◽  
Flight Duration ◽  
Migratory Activity ◽  
South Wales ◽  
Eastern Australia ◽  
Synoptic Conditions ◽  
Yorke Peninsula

AbstractAerial sampling for Nysius vinitor Bergroth was undertaken in the surface and upper air, at altitudes of 2 and 100-300 m, respectively, at Trangie in central New South Wales and at Corny Point, Yorke Peninsula, South Australia. Insects were sampled for 15 periods, each of 3-11 days, between October 1979 and February 1984, covering all months except January, March and May. N. vinitor was one of the most abundant insects caught in the upper air during the day and night (mean density of 652/106 m3), while the congeneric N. clevelandensis Evans was rarely caught at any time. N. vinitor was caught in all months sampled except for the winter months of July and August, and the largest daily catches occurred in September. Females were generally less common than males, although the relative incidence in the upper air catches frequently increased significantly from day to night. Fewer mature females were caught in the upper air (0-16·8%) than at the surface (0-48·4%). Densities were generally much greater in the surface air than in the upper air, although during the major flights of spring, there was less than a two-fold difference, indicating increased migratory activity. Migration occurred in a range of synoptic conditions resulting in the displacement of individuals in a variety of directions and distances depending on synoptic flow at the time of flight. Major migrations occurred at night, following dusk take-off, in disturbed weather associated with prefrontal airflows. These resulted in net southward displacements of ca 200-300 km depending on flight duration. It is suggested that major immigration flights into central-western New South Wales and regions to the south regularly occur in early spring (September-October) and probably arise from breeding areas in subtropical latitudes.

Population ranges of Miniopterus schreibersii (Chiroptera) in south-eastern Australia

1969 ◽  
Vol 17 (4) ◽  
pp. 665 ◽  
Author(s):  
PD Dwyer
Keyword(s):  
New South ◽  
New South Wales ◽  
South Australia ◽  
South Eastern ◽  
Navigational Cues ◽  
South Wales ◽  
Eastern Australia ◽  
North Eastern ◽  
Western Victoria ◽  
South Eastern Australia

In south-eastern Australia banding of M. schreibersii has been concentrated in four areas: north-eastern New South Wales, south-eastern New South Wales, south-eastern Victoria, and south-western Victoria and south-eastern South Australia. The present paper analyses 2083 reported movements. Only 17 of these are from one of the four areas to another with the longest movement being 810 miles. Biologically and geographically separate populations of M. schreibersii are recognized in both north-eastern and south-eastern New South Wales. Each population has its basis in dependence upon a specific nursery site which is used annually by nearly all adult females in that population. Boundaries of population ranges in New South Wales are considered to be prominent features of physiography (i.e. divides). Bats move between population ranges less often than they move within population ranges. This cannot be explained solely in terms of the distances separating roosts. Available movement records from Victoria and South Australia are consistent with the pattern described for New South Wales. Two biologically recognizable populations (i.e, different birth periods) occur in south-western Victoria and south-eastern South Australia but these may have overlapping ranges. Only one nursery colony of M. schreibersii is known from south-eastern Victoria. On present evidence it remains possible that the apparent integrity of the population associated with this nursery is merely a consequence of distance from other areas of banding activity. Detailed analyses of movements in bats may provide direct evidence as to the kinds of cues by which a given species navigates. Thus the physiographic basis described for population ranges in New South Wales is consistent with the view that M. schreibersii may orientate to waterways or divides or both. The probability that there are area differences in the subtlety or nature of navigational cues is implied by the different physiographic circumstances of south-western Victoria and south-eastern South Australia. It is suggested that knowledge of population range boundaries may aid planning of meaningful homing experiments.

A Parapatric Boundary between Ranidella signifera and R. riparia (Anura: Leptodactylidae) in South Australia

1982 ◽  
Vol 30 (1) ◽  
pp. 49 ◽  
Author(s):  
FJ Odendaal ◽  
CM Bull
Keyword(s):  
Competitive Advantage ◽  
Close Association ◽  
South Australia ◽  
Wide Distribution ◽  
Habitat Types ◽  
South Eastern ◽  
The North ◽  
Flinders Ranges ◽  
Eastern Australia ◽  
Overlap Area

Ranidella signifera has a wide distribution in south-eastern Australia; R. riparia is endemic to the Flin- ders Ranges in South Australia. The ranges of the two species are largely allopatric, but they contact and overlap in a zone about 10 km wide, in the southern Flinders Ranges. The nature of the creeks changes across this zone. Immediately to the south and east, where only R. signifera is found, the creeks are slow-flowing and heavily vegetated, with mud or sand substrates. To the north and west the creeks are swift-flowing, and have rocky substrates and little vegetation; only R. riparia is found in these. In the sympatric overlap zone creeks are heterogeneous, with both habitat types represented. The close association between species and creek habitat is lost in populations not immediately adjacent to the overlap zone. This implies that each species can survive in both creek habitats but that R. riparia has a competitive advantage in swift, rocky creeks and R, signifera has an advantage in slow, vegetated creeks. This prevents either species from expanding its distribution beyond the narrow overlap area.

Crayfish bio-gastroliths from eastern Australia and the middle Cretaceous distribution of Parastacidae

2019 ◽  
Vol 157 (7) ◽  
pp. 1023-1030
Author(s):  
Phil R. Bell ◽  
Russell D. C. Bicknell ◽  
Elizabeth T. Smith
Keyword(s):  
Southern Hemisphere ◽  
Rift Valley ◽  
Fossil Record ◽  
New South ◽  
Significant Proportion ◽  
Freshwater Ecosystems ◽  
The North ◽  
Calcium Storage ◽  
South Wales ◽  
Eastern Australia

AbstractFossil crayfish are typically rare, worldwide. In Australia, the strictly Southern Hemisphere clade Parastacidae, while ubiquitous in modern freshwater systems, is known only from sparse fossil occurrences from the Aptian–Albian of Victoria. We expand this record to the Cenomanian of northern New South Wales, where opalized bio-gastroliths (temporary calcium storage bodies found in the foregut of pre-moult crayfish) form a significant proportion of the fauna of the Griman Creek Formation. Crayfish bio-gastroliths are exceedingly rare in the fossil record but here form a remarkable supplementary record for crayfish, whose body and trace fossils are otherwise unknown from the Griman Creek Formation. The new specimens indicate that parastacid crayfish were widespread in eastern Australia by middle Cretaceous time, occupying a variety of freshwater ecosystems from the Australian–Antarctic rift valley in the south, to the near-coastal floodplains surrounding the epeiric Eromanga Sea further to the north.

Larval distribution and abundance of blue and spotted warehous (Seriolella brama and S. punctata: Centrolophidae) in south-eastern Australia

2001 ◽  
Vol 52 (4) ◽  
pp. 631 ◽  
Author(s):  
B. D. Bruce ◽  
F. J. Neira ◽  
R. W. Bradford
Keyword(s):  
Life Histories ◽  
New South ◽  
South Australia ◽  
South Eastern ◽  
Larval Distribution ◽  
South Wales ◽  
Spawning Areas ◽  
Eastern Australia ◽  
Commercially Important ◽  
South Eastern Australia

The early life histories of the commercially important blue and spotted warehous (Seriolella brama and S. punctata) were examined on the basis of archived ichthyoplankton samples collected over broad areas of southern Australia. Larvae of both species were widely distributed during winter and spring within shelf and slope waters. Larvae of S. brama were recorded from Kangaroo Island, South Australia (SA), to southern New South Wales (NSW). Seriolella punctata larvae were recorded from western Tasmania to southern NSW. Back-calculated spawning dates, based on otolith microstructure, indicated that spawning predominantly occurs during late July and August but that the timing of spawning varies between regions. The abundances of small larvae (<5. 0 mm body length) were highest for both species off western Tasmania and southern NSW. No small S. brama larvae were recorded between southern Tasmania and southern NSW, whereas low but consistent numbers of small S. punctata larvae were found between these regions. The data suggest that there are separate spawning areas for S. brama in western and eastern regions of Australia’s South East Fishery. The pattern for S. punctata is less clear, but suggests a more continuous link among populations in south-eastern Australia.

Marine and estuarine phylogeography of the coasts of south-eastern Australia

2016 ◽  
Vol 67 (11) ◽  
pp. 1597 ◽  
Author(s):  
D. J. Colgan
Keyword(s):  
South Australia ◽  
Rocky Intertidal ◽  
Phylogeographic Structure ◽  
Subtidal Zone ◽  
South Eastern ◽  
South Wales ◽  
Eastern Australia ◽  
North Eastern ◽  
Genetic Techniques ◽  
South Eastern Australia

Understanding a region’s phylogeography is essential for an evolutionary perspective on its biological conservation. This review examines the phylogeographic structures in south-eastern Australia that have been revealed by mitochondrial DNA sequencing and other genetic techniques and examines whether they can be explained by known factors. The review covers species that occur in the intertidal zone or, even infrequently, in the shallow subtidal zone. The coasts most frequently associated with phylogeographic structure are the boundaries between the Peronian and Maugean biogeographical provinces in southern New South Wales and the Maugean and Flindersian provinces in South Australia, the areas in Victoria and north-eastern Tasmania separated by the Bassian Isthmus at glacial maxima, long sandy stretches without rocky intertidal habitat on the Ninety Mile Beach in Victoria and the Younghusband Peninsula–Coorong in South Australia, southern Tasmania and Bass Strait, which acts as a barrier for littoral species.

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