Vegetation history and water fluctuations at Lake Leake, south-eastern South Australia. 1. 10,000 B.P. to present

1974 ◽  
Vol 22 (4) ◽  
pp. 719 ◽  
Author(s):  
JR Dodson

The stratigraphy and detailed pollen analysis of the top 4 m of sediment in Lake Leake were used to describe the vegetation history and past changes in the water level in the lake basin. Some of the changes described have climatic significance. Six radiocarbon dates are used to place a chronology on these events and the results are used to compare previous work carried out in western Victoria. It is suggested that in south-eastern South Australia, immediately prior to 10,000 B.P., conditions were drier than at present and that after this time conditions became wetter, the wettest period of the last 10,000 years occurring between 6900 and 5000 B.P. After this time conditions became drier, marginally wetter again between 2000 and 1300 B.P., then relatively dry until the present day. Keys to aid in the identification of pollen of the Casuarinaceae, Myriophyllum and the Myrtaceae for species growing in the Lower South-East of South Australia are given.


1975 ◽  
Vol 23 (1) ◽  
pp. 123 ◽  
Author(s):  
JR Dodson ◽  
IB Wilson

The swamp and sclerophyll vegetation of Marshes Swamp is discussed in terms of soils and water regimes. Two swamps, Mt. Burr Swamp and Blue Tea Tree Swamp, which form part of Marshes Swamp, are looked at in particular and their stratigraphy and history are reconstructed. Cores from the swamp were pollen-analysed and the vegetation history of the swamps is described in terms of plant succession and local climatic change. Four radiocarbon dates were obtained and these were used to date the major local vegetational history events following dune build-up and vulcanism. These also allowed some insight into the age of soil development in the swamp.



2020 ◽  
Vol 42 (3) ◽  
pp. 321
Author(s):  
B. D. Cooke

Swamp wallabies have dramatically extended their distribution through western Victoria and south-eastern South Australia over the last 40 years. Newspaper reports from 1875 onwards show that on European settlement, wallaby populations were confined to eastern Victoria, including the ranges around Melbourne, the Otway Ranges and Portland District of south-western Victoria, and a tiny part of south-eastern South Australia. Populations contracted further with intense hunting for the fur trade until the 1930s. In the late 1970s, however, wallabies began spreading into drier habitats than those initially recorded. Possible causes underlying this change in distribution are discussed; some seem unlikely but, because wallabies began spreading soon after the introduction of European rabbit fleas as vectors of myxomatosis, the cumulative effects of releases of biological agents to control rabbits appear important. A caution is given on assuming that thick vegetation in high-rainfall areas provides the only habitat suitable for swamp wallabies, but, most importantly, the study shows how native mammals may benefit if rabbit abundance is reduced.



1975 ◽  
Vol 23 (5) ◽  
pp. 815 ◽  
Author(s):  
JR Dodson

A drill core from Lake Leake contains a sedimentary sequence extending from about 50,000 B.P. until the present. This paper discusses the results of the pollen analyses and six radiocarbon dates which span the period from about 50,000 until about 10,000 B.P. There are core sections which yielded low numbers of pollen and thus there are gaps in the vegetation record. It is suggested that open eucalypt woodland was replaced by eucalypt woodland with heath at about 50,000 B.P. and remained until about 39,000 B.P. Open woodland then returned but was replaced by eucalypt woodland with heath by 38,000 B.P. Some time after 35,000 B.P., open eucalypt woodland conditions returned and persisted until near 10,000 B.P. when Casuarina stricta migrated into the area. Through- out the period in question the climate was drier than it has been in the last 10,000 radiocarbon years. There were wet periods about 50,000 and 39,000 B.P. and from 38,000 to 35,000 B.P. The character of the sediments and the relative amounts of pollen preserved suggest that conditions were relatively dry from 50,000 to 39,000 B.P. and from after 35,000 until near 10,000 B.P. The lake was driest during the period of the last glaciation but the presence of eucalypt pollen is interpreted as indicating that the average annual minimum temperature was above 10�C and the average annual rainfall was above 20-25 cm.



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.



1999 ◽  
Vol 47 (3) ◽  
pp. 407 ◽  
Author(s):  
Adriana García

The charophytes (Charales, Charophyta) from south-eastern South Australia and south-western Victoria were studied on the basis of collections from 56 waterbodies, 39 of which included charophytes. Chara globularis var. globularis (Thuillier) Wood, C. globularis var. virgata (KÜtzing) Wood, C. fibrosa var. fibrosa (Agardh ex Bruzelius) Wood, C. fibrosa var. acanthopitys (Braun) Wood, C. hookeri Braun, C. preissii (Braun) Wood, Lamprothamnium macropogon (Braun) Ophel, Nitella ignescens García, N. ungula García, N. lhotzkyi (Braun) Braun, N. aff. lhotzkyi, and N. congesta (Brown) Braun were recognised. An identification key for these species makes determination possible. A brief characterisation of the environment where the charophytes were found is provided, as a first approximation of the ecological requirements of Australian charophytes. At this stage their distribution can be mainly related to salinity, with charophytes living in fresh to hypersaline conditions (0.0–58.0 g L–1). Special attention is put on L. macropogon, a euryhaline calcifying species, which has the broadest distribution in the area. The floristic analysis shows endemism, dioecism and a high diversification of non-calcifying taxa as the main characteristics of the charophyte flora analysed.



1999 ◽  
Vol 47 (5) ◽  
pp. 755 ◽  
Author(s):  
Fiona Coates ◽  
J. B. Kirkpatrick

The major centres of local endemism and richness at the species level and below in Spyridium Fenzl are located on the southern coast of Western Australia and in south-eastern South Australia. There are only a few Spyridium taxa with ranges that transgress the boundaries of the following four regions: south- western Western Australia; south-eastern South Australia and western Victoria; eastern Victoria, New South Wales and southern Queensland; Tasmania. Synthetic climatic variables were generated for all recorded populations of Spyridium taxa. Variabilities in these were related to the maximum geographic ranges of taxa in Australia as a whole, and within the regions, in order to test the hypothesis that narrow endemism is explained by climatic restriction since the last glacial. In Australia as a whole, local endemics are both narrowly and widely distributed climatically, as are more widespread Spyridiumtaxa, and there were no significant relationships between the climatic and geographic ranges of taxa confined to the Australian mainland regions. However, Tasmanian taxa exhibited a strong positive relationship. Restriction of range as a result of climate change is an unlikely explanation for local endemism in Spyridium in mainland Australia, where topographic and climatic gradients are generally subdued, and which apparently experienced less severe climatic oscillations during the Quaternary. However, this hypothesis cannot be rejected for Tasmania, which experienced more extreme Quaternary climatic fluctuations than the present-day areas of mediterranean climate, and hence more severe fluctuations in the area and location of climatically suitable habitats.



1982 ◽  
Vol 9 (2) ◽  
pp. 221 ◽  
Author(s):  
J Short ◽  
GC Grigg

The densities of red and grey kangaroos in western Victoria and south-eastern South Australia were assessed by aerial survey. Much of the 133000-km2 area surveyed was farmed intensively for wheat and sheep but a significant proportion was largely unaltered mallee woodland or mallee heath. Of the total area, 85% had a density of less than one kangaroo per square kilometre, and 32% had a density of less than 0.01 km-2, values considerably lower than those reported for pastoral areas in New South Wales and South Australia. Low densities in settled areas are attributed to intensive agricultural practices, small landholdings and lack of tree cover. Low densities in mallee may be due to the lack of palatable grasses and the absence of permanent watering points.





2005 ◽  
Vol 19 (4) ◽  
pp. 325 ◽  
Author(s):  
Hiroshi Fukuda ◽  
Winston F. Ponder

A new genus, Cryptassiminea, is introduced for the taxon previously known as Assiminea buccinoides (Quoy & Gaimard). These small gastropods are abundant in mangrove and salt marsh habitats in south-eastern and subtropical eastern Australia. Seven species (five new) are recognised using morphological characters in the complex previously treated as a single species. Five taxa have rather narrow ranges while the other two are widespread and often sympatric. Two groups of species are recognised. One contains Cryptassiminea buccinoides, widespread in south-east and east Australia, and two closely related allopatric taxa from South Australia and south-eastern Tasmania (C. adelaidensis, sp. nov. and C. kershawi, sp. nov.). A second group of species is typified by Cryptassiminea tasmanica (Tenison-Woods), also widespread in east and south-east Australia and often sympatric with C. buccinoides. Allied to C. tasmanica, are two closely related taxa from western Victoria: C. glenelgensis, sp. nov. from the Glenelg River estuary and C. surryensis, sp. nov. from the Surry River estuary and Western Port, in the vicinity of Geelong. A distinctive species, Cryptassiminea insolata, sp. nov. from the east coast of Queensland, also has similarities with C. tasmanica. A cladistic analysis using morphological characters of the Cryptassiminea taxa and three other genera of Assimininae, with an omphalotropidine as the outgroup, resulted in a single tree. The new genus has rather poor support, possibly because many of its characters appear to be plesiomorphic within Assimineinae. Cryptassiminea is defined by a unique combination of characters but lacks any obvious synapomorphy. Two clades within Cryptassiminea are well supported, each containing the species-groups referred to above.



2014 ◽  
Vol 62 (4) ◽  
pp. 294 ◽  
Author(s):  
David Peacock ◽  
Ian Abbott

Since the European settlement of Australia in 1788, 25 mainland terrestrial mammal species have become extinct, more than on any other continent during this period. To determine if the causal factors are still active, it is necessary to better understand the species and their status preceding these regional extirpations or extinctions, and examine the historical record for clues to the cause(s) of these declines. From an extensive review of historical material, primarily newspaper accounts, we collated >2700 accounts of quolls. We discovered 36 accounts that demonstrate the propensity for quolls to become hyperabundant. The geographical distribution of accounts implies that most refer to Dasyurus viverrinus, but an account from Normanton district (Queensland) likely applies to D. hallucatus. More than 110 accounts demonstrate that disease/parasite epizootics occurred in south-eastern Australia, commencing on mainland Australia possibly in the goldfields region of Victoria in the 1850s, or in south-eastern South Australia and south-western Victoria in the mid to late 1860s, and implicate these as the initial primary factor in the regional extirpation of Australia’s quolls. The loss of D. viverrinus populations in south-eastern Australia was reportedly from population abundances and densities that were sporadically extraordinarily high, hence their loss appears more pronounced than previously suspected. Accounts describing the widespread, rapid and major loss of quolls suggest the possible involvement of several pathogens. Ectoparasites such as Uropsylla tasmanica and ticks appear to be described in detail in some accounts. A few others state comortality of Felis catus and Canis lupus familiaris, suggestive of a disease of either or both of these species, such as Canine Distemper Virus, a morbillivirus with a propensity to be non-host specific, that may have caused the decline of the quolls, perhaps vectored by the reported ectoparasites. We also collated 23 presumed independent accounts of cats negatively impacting quolls, two of which describe significant mortality, and three presumed independent accounts of fox predation. These highlight the capacity of both of these introduced predators to have reduced quoll distribution and abundance.



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