scholarly journals Eocene monsoon forests in central Australia?

1996 ◽  
Vol 9 (2) ◽  
pp. 95 ◽  
Author(s):  
DR Greenwood

The Australian Tertiary plant fossil record documents rainforests of a tropical to temperate character in south-eastern and south-western Australia for much of the Early Tertiary, and also shows the climatically mediated contraction of these rainforests in the mid to Late Tertiary. The fossil record of Australian monsoon forests, that is semi-evergreen to deciduous vine forests and woodlands of the wet-dry tropics, however, is poorly known. Phytogeographic analyses have suggested an immigrant origin for some floral elements of present day monsoon forests in northern Australia, while other elements appear to have a common history with the tropical rainforests sensu stricto and/or the sclerophyllous flora. Early Tertiary macrofloras in northern South Australia may provide some insight into the origins of Australian tropical monsoon forests. The Middle Eocene macrofloras of the Poole Creek palaeochannel, and the ?Eocene-Oligocene silcrete macrofloras of Stuart Creek, both in the vicinity of modern Lake Eyre South, have foliar physiognomic characteristics which distinguish them from both modern rainforest and Eocene-Oligocene floras from south-eastern Australia. Preliminary systematic work on these floras suggests the presence of: (1) elements not associated today with monsoon forests (principally 'rainforest' elements, e.g. Gymnostoma, cf. Lophostemon, cf. Athertonia, Podocarpaceae, ?Cunoniaceae); (2) elements typical of both monsoon forests and other tropical plant communities (e.g. cf. Eucalyptus, cf. Syzygium, and Elaeocarpaceae); (3) elements likely to be reflecting sclerophyllous communities (e.g. cf. Eucalyptus, Banksieae and other Proteaceae); and (4) elements more typically associated with, but not restricted to, monsoon forests (e.g. Brachychiton). The foliar physiognomic and floristic evidence is interpreted as indicating a mosaic of gallery or riverine rainforests, and interfluve sclerophyllous plant communities near Lake Eyre in the Early Tertiary; deciduous forest components are not clearly indicated. Palaeoclimatic analysis of the Eocene Poole Creek floras suggests that rainfall was seasonal in the Lake Eyre area in the Eocene; however, whether this seasonality reflects a monsoonal airflow is not clear.

2001 ◽  
Vol 14 (2) ◽  
pp. 193 ◽  
Author(s):  
Robert S. Hill ◽  
David C. Christophel

Two new macrofossil species of Dacrydium (Podocarpaceae), D. fimbriatus (with dimorphic foliage) and D. mucronatus, are described from Middle Eocene sediments at Nelly Creek just south of Lake Eyre South. These species extend the number of Dacrydium macrofossil species from four to six, the macrofossil range from south-eastern to central Australia and the earliest macrofossil record of the genus from the Early Oligocene to Middle Eocene. On the basis of the low numbers and poor development of epiphyllous germlings, these species were probably growing in a region where water availability was reduced compared with Paleogene sites in south-eastern Australia, but the morphology of the foliage does not reflect that.


1998 ◽  
Vol 11 (6) ◽  
pp. 711 ◽  
Author(s):  
Robert S. Hill ◽  
Leonie J. Scriven

A re-investigation of macrofossils previously referred to the extantpodocarpaceous genus Falcatifolium Laubenfels shows thatno records can be sustained. Falcatifolium australisD.R.Greenwood from Middle Eocene sediments in Victoria bears littleresemblance to extant species in the genus and is transferred to the newfossil genus Sigmaphyllum R.S.Hill & L.J.Scriven.Specimens from Early Oligocene sediments in Tasmania previously assigned toFalcatifolium are described as a second species ofSigmaphyllum, S. tasmanensisR.S.Hill & L.J.Scriven, and specimens from mid to late Eocene sediments inTasmania previously assigned to Falcatifolium do notbelong to that genus, although their true generic affinities are uncertain.Dispersed cuticle specimens from Late Eocene–Oligocene sediments inSouth Australia referred to Falcatifolium are notreliable records of the genus and require further investigation. However,Dacrycarpus eocenica D.R.Greenwood, from Middle Eocenesediments in Victoria is transferred to Falcatifolium,and is similar to the extant species F. angustumLaubenfels, which has a leaf morphology unusual for the genus.Falcatifolium eocenica (D.R.Greenwood) R.S.Hill & L.J.Scriven is the only reliable record of the genus in the Australian fossilrecord to date.


1999 ◽  
Vol 50 (7) ◽  
pp. 1233 ◽  
Author(s):  
G. H. Baker ◽  
P. J. Carter ◽  
V. J. Barrett

The earthworm fauna of pastures in south-eastern Australia is dominated by exotic lumbricid earthworms, in particular the endogeic species, Aporrectodea caliginosa and A. trapezoides. Anecic species such as A. longa are very rare. All 3 species were introduced within cages in 10 pastures on a range of soil types within the region. Five months later, A. longa had generally survived the best and A. trapezoides the worst. The survivals and weights of individual worms varied between sites for all 3 species. The survivals of A. caliginosa and A. longa, and to a lesser extent A. trapezoides, were positively correlated with soil clay content. The weights of A. caliginosa and A. longa, but not A. trapezoides, were positively correlated with soil P content. The survivals and weights of A. longa and A. trapezoides and the weights only of A. caliginosa decreased with increasing inoculation density, suggesting increased intraspecific competition for resources, particularly in the first two species. A. longa reduced the abundance and biomass of the exotic acanthodrilid earthworm, Microscolex dubius, at one site, and the total biomass of 3 native megascolecid species at another, when these latter species occurred as contaminants in A. longa cages. The addition of lime had no effect on the survivals and weights of A. caliginosa, A. longa, and A. trapezoides, although the soils were acid at the sites tested. The addition of sheep dung increased the survival and weights of some species at some sites. Mechanical disturbance of the soil within cages reduced the survivals of A. longa and A. trapezoides. A. longa was released without being caged at 25 sites within one pasture in South Australia. Four years later, it was recovered at all release points. A. longa has the potential to colonise pastures widely throughout the higher rainfall regions of south-eastern Australia.


2015 ◽  
Vol 21 (4) ◽  
pp. 271 ◽  
Author(s):  
Gregory R. Johnston ◽  
Maxwell H. Waterman ◽  
Clare E. Manning

Globally, pelican populations have decreased, with three species being of conservation concern. Australian pelicans (Pelecanus conspicillatus) are not regarded as endangered, but have declined across south-eastern Australia. Information on their movements and causes of mortality are required to interpret the importance of these regional declines to the species’ global population. We explored patterns of movement and causes of mortality by analysing recoveries from 14 615 Australian pelicans banded over 37 years between 1969 and 2006. Data from 243 leg band recoveries showed that Australian pelicans move distances of up to 3206 km, and travel across the species’ entire geographic range, within a year of fledging. We found little evidence for the popular notion that these birds move en masse from the coast to inland areas in response to flooding rains. Maximum recorded age of a banded Australian pelican was 15 years. The banding data suggest that the regional pelican declines could reflect long-distance movements rather than an overall population response. However, a concentration of band returns from south-eastern Australia where the declines have been recorded, and the high incidence of human-induced deaths (16.4%) suggest otherwise. Accurate assessment of population trends in long-lived, long-distance nomads such as Australian pelicans requires assessment at a continental scale. Our results emphasise the importance of knowledge about fundamental aspects of a species’ biology for accurate interpretation of regional population declines.


1969 ◽  
Vol 17 (4) ◽  
pp. 665 ◽  
Author(s):  
PD Dwyer

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.


1982 ◽  
Vol 30 (1) ◽  
pp. 49 ◽  
Author(s):  
FJ Odendaal ◽  
CM Bull

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.


2001 ◽  
Vol 52 (4) ◽  
pp. 631 ◽  
Author(s):  
B. D. Bruce ◽  
F. J. Neira ◽  
R. W. Bradford

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.


2016 ◽  
Vol 67 (11) ◽  
pp. 1597 ◽  
Author(s):  
D. J. Colgan

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.


2019 ◽  
Vol 59 (4) ◽  
pp. 601 ◽  
Author(s):  
R. A. Hunter ◽  
P. M. Kennedy ◽  
E. J. Sparke

Statistical data from the years 1998–2005 were used to investigate the capacity of the grain industry in eastern Australia to supply the grain necessary for inclusion of 10% ethanol in petrol (E10), in addition to the demands of grain for feedlot cattle. Evidence is provided that the variations in grain yields and grain consumption by cattle in these years are representative of the on-going situation and that interpretations and conclusions have continuing relevance. During 1998–2005, annual production of cereal grains in eastern Australia varied between 10 and 25 million tonnes. Similar fluctuations (11 and 27 million tonnes) in annual grain yields were observed between 2006 and 2014. The Australian potential requirement for E10 ethanol is ~2500 ML annually, with a grain usage of 6.1–7.6 million tonnes depending on the grain sources used. Established national grain demand for ruminant and monogastric livestock, human consumption and other domestic uses is ~7.5 million tonnes per year. In years of average or higher grain yields in Queensland, New South Wales, Victoria and South Australia, the combined grain surpluses are more than sufficient for E10 ethanol to be produced domestically. In the years of the lowest grain yields, the surplus over more traditional usages is sufficient to satisfy only 50% of potential demand for E10. The greatest densities of feedlot cattle are in south-eastern Queensland, northern New South Wales and in the Murrumbidgee region of southern New South Wales. On a regional basis, the grain surplus to feedlot demand in most years in south-eastern Queensland is not sufficient to satisfy requirement for ethanol production without competition for grain. In years of highest yields, the grain surplus was sufficient for a 240-ML ethanol plant. Northern New South Wales could support at least two 400-ML plants in years of average and above yields, once established grain demands are met. The grain shortfall in years of lowest yield for one 400-ML plant is about half a million tonnes. Grain surpluses in average years in the Murrumbidgee region are sufficient to support at least one 400-ML plant. In years of lowest yield, only a 160-ML plant could be supported without competition for grain.


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