Factors affecting post-fire seedling establishment of selected mallee understorey species

2000 ◽  
Vol 48 (1) ◽  
pp. 59 ◽  
Author(s):  
J. S. Cohn ◽  
R. A. Bradstock
Keyword(s):  
Large Scale ◽  
Prescribed Burning ◽  
New South ◽  
Eucalyptus Species ◽  
Factors Affecting ◽  
Acacia Species ◽  
Introduced Herbivores ◽  
South Wales ◽  
Rabbit Grazing ◽  
Seedling Germination

Factors affecting the survival of post-fire germinants in mallee communities, in central western New South Wales, were examined. Experiments compared the relative effects of native and introduced herbivores (kangaroos, goats, rabbits), after small- and large-scale fires (20–50 and > 10 000 ha, respectively), with particular emphasis on edge effects, seedling clustering, topography and eucalypt canopy presence. The experiments (1985–1997) focused on common understorey species Acacia rigens Cunn. ex Don, A. wilhelmiana F.Muell. and Triodia scariosa N.T.Burb. subsp. scariosa, in mallee dominated by Eucalyptus species. Following a large fire (1985), high spring rainfall and rabbit grazing on A. rigens only, survival of Acacia species and T. scariosa remained relatively high 4 years later (60–70%). After small burns (1987, 1988), low spring rainfall and grazing by rabbits and kangaroos, survival of Acacia species declined to between 0 and 30% of the germinants by the second summer. In most cases, local extinction had occurred within 8 years. After small burns (1988, 1989) and low spring rainfall, the survival of T. scariosa declined to between 0 and 35% of germinants by the second summer (effect of grazing unknown). No consistent effect of edge, topography and eucalypt canopy was found. Survival of clustered Acacia seedlings was between 10 and 20% lower than unclustered seedlings. Given the high frequency of low rainfall and its interaction with grazing, prescribed burning of mallee for wildfire control and nature conservation may require the local elimination of rabbits and a reduction in kangaroo numbers, especially in the first spring and summer following seedling germination.

ASSISTED EMIGRATION AND THE MORAL DILEMMAS OF THE MID-VICTORIAN IMPERIAL STATE

2016 ◽  
Vol 59 (4) ◽  
pp. 1027-1049 ◽  
Author(s):  
PHILIP HARLING
Keyword(s):  
Large Scale ◽  
New South ◽  
Social Engineering ◽  
Moral Dilemmas ◽  
Irish Famine ◽  
Slave Emancipation ◽  
South Wales ◽  
Ethical Controversy ◽  
Plantation Society ◽  
Imperial State

ABSTRACTThis article examines three voyages of the late 1840s to advance the argument that emigration – often treated by its historians as ‘spontaneous’ – actually involved the laissez-faire mid-Victorian imperial state in significant projects of social engineering. The tale of the Virginius exemplifies that state's commitment to taking advantage of the Famine to convert the Irish countryside into an export economy of large-scale graziers. The tale of the Earl Grey exemplifies its commitment to transforming New South Wales into a conspicuously moral colony of free settlers. The tale of the Arabian exemplifies its commitment to saving plantation society in the British Caribbean from the twin threats posed by slave emancipation and free trade in sugar. These voyages also show how the British imperial state's involvement in immigration frequently immersed it in ethical controversy. Its strictly limited response to the Irish Famine contributed to mass death. Its modest effort to create better lives in Australia for a few thousand Irish orphans led to charges that it was dumping immoral paupers on its most promising colonies. Its eagerness to bolster sugar production in the West Indies put ‘liberated’ slaves in danger.

Some human, aircraft and animal factors affecting aerial surveys: how to enumerate animals from the air

2008 ◽  
Vol 35 (4) ◽  
pp. 258 ◽  
Author(s):  
Peter J. S. Fleming ◽  
John P. Tracey
Keyword(s):  
Visual Acuity ◽  
New South ◽  
Human Memory ◽  
Aerial Survey ◽  
Factors Affecting ◽  
Counting Error ◽  
Aerial Surveys ◽  
South Wales ◽  
Survey Estimates ◽  
Aerial Platforms

Aerial surveys of wildlife involve a noisy platform carrying one or more observers moving over animals in order to quantify their abundance. This simple-sounding system encapsulates limits to human visual acuity and human concentration, visual attention, salience of target objects within the viewed scene, characteristics of survey platforms and facets of animal behaviours that affect the detection of animals by the airborne observers. These facets are too often ignored in aerial surveys, yet are inherent sources of counting error. Here we briefly review factors limiting the ability of observers to detect animals from aerial platforms in a range of sites, including characteristics of the aircraft, observers and target animals. Some of the previously uninvestigated limitations identified in the review were studied in central and western New South Wales, showing that inaccuracies of human memory and enumeration processes are sources of bias in aerial survey estimates. Standard protocols that minimise or account for the reviewed factors in aerial surveys of wildlife are recommended.

Variation in algal assemblages on wave-exposed rocky shores in New South Wales

1998 ◽  
Vol 49 (3) ◽  
pp. 241 ◽  
Author(s):  
A. J. Underwood ◽  
M. G. Chapman
Keyword(s):  
Large Scale ◽  
New South ◽  
New South Wales ◽  
Temporal Patterns ◽  
Explanatory Models ◽  
Small Scale ◽  
Rocky Shores ◽  
Spatial And Temporal Patterns ◽  
South Wales ◽  
Algal Assemblages

Data were collected in New South Wales from replicate sites on five wave-exposed shores separated by hundreds of kilometres at three-monthly intervals for four years, to examine large and small spatial and temporal patterns in low-shore algal assemblages. These data were used to test hypotheses from the models that algal assemblages show large-scale, predictable changes in structure or, alternatively, that variation from time to time is small-scale and differs from shore to shore or site to site on a shore. There was considerable variation at all scales examined — among replicate quadrats within sites, between sites on a shore and among shores. Similarly, assemblages differed from one sampling period to the next and changes in the assemblages over time periods of three months were as great as from year to year. These changes were interactive, with no two sites or shores showing similar temporal patterns. Thus, understanding diversity along a coast-line requires detailed understanding of local processes. Without adequate spatial and temporal replication in sampling designs and without explanatory models, the large and complex variability in intertidal assemblages at different scales cannot be documented and understood.

Factors affecting the germination of Giant Parramatta grass

1997 ◽  
Vol 37 (4) ◽  
pp. 439 ◽  
Author(s):  
T. S. Andrews ◽  
C. E. Jones ◽  
R. D. B. Whalley
Keyword(s):  
Leaf Extract ◽  
New South ◽  
New South Wales ◽  
North Coast ◽  
Factors Affecting ◽  
The North ◽  
South Wales ◽  
Seed Fall ◽  
Allelopathic Interactions ◽  
And Control

Summary. Four experiments were conducted to determine the effects of temperature, light and leaf extract solutions on the germination of Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] collected from a population on the North Coast of New South Wales. In the first experiment, seeds were subjected to one of a range of temperature combinations immediately after collection and again after 8 and 27 weeks. Germination was restricted to a narrow range of alternating temperatures with a peak at 35°C day/15°C night when seeds were tested immediately after collection. More seeds germinated when the samples had been stored, although germination remained depressed at constant temperatures. These data indicate that freshly collected GPG seeds are subject to primary dormancy and that few would germinate in the field immediately after seed fall. In a second experiment, seeds were buried beneath leaf litter in a pasture immediately after collection. After 7 months, the seeds were exhumed and subjected to either constant (20°C) or alternating (35/15°C) temperatures in either full light, reduced red:far-red (R : FR) light or dark treatments. Over 95% of GPG seeds germinated when subjected to alternating temperatures, regardless of light treatment. At constant temperatures, 97% of seeds germinated under full light, 59% at reduced R : FR light and <1% in dark treatments. A germination response to alternating temperatures and/or light treatments has been reported in pasture weeds and may be an adaptation to detecting gaps in the pasture canopy. Consequently, the germination of GPG in a pasture may be manipulated to some extent by altering the amount of pasture cover using grazing management, mowing and fertiliser applications. In experiment 3, leaves from a range of coastal grasses were mixed with water and the solutions were used to germinate GPG seeds. Solutions extracted from setaria (Setaria sphacelata) leaves completely inhibited GPG germination while 27% of GPG seeds germinated when imbibed with kikuyu leaf extract solution. Solution extracted from carpet grass (Axonopus affinis) leaves had the least effect on GPG germination. In experiment 4, the effects of solutions that had been leached from the leaves of either setaria or carpet grass on seed germination, and root and shoot lengths of GPG seedlings were compared. Germination was less inhibited by leachate solutions compared with the extract solutions used in experiment 3. Seedlings in setaria leachates had significantly shorter roots and shoots than both those germinated in carpet grass leachates and control seedlings. This may explain, at least in part, why carpet-grass-based pastures are readily infested with GPG while setaria-based pastures are relatively resistant to infestation. The potential for allelopathic interactions between GPG and setaria to be fully utilised to reduce the abundance of GPG in coastal New South Wales pastures is discussed.

Fire in the Mallee Shrublands of Western New South Wales.

1980 ◽  
Vol 2 (1) ◽  
pp. 104 ◽  
Author(s):  
JC Noble ◽  
AW Smith ◽  
HW Leslie
Keyword(s):  
Case Studies ◽  
Prescribed Burning ◽  
New South ◽  
New South Wales ◽  
Management Implications ◽  
South Wales ◽  
Wildfire Hazard ◽  
Western Division

This article describes the effects of the 1974175 wildfires on the mallee vegetation in the Western Division of New South Wales using two properties as case studies. The management implications arising from these experiences are described in some detail, particularly the potential for some form of management based on periodic prescribed burning to promote herbage productivity and also to reduce any future wildfire hazard. The need for appropriate research to be undertaken in this field is also discussed.

Large-scale patterns in habitat structure on subtidal rocky reefs in New South Wales

2000 ◽  
Vol 51 (3) ◽  
pp. 255 ◽  
Author(s):  
N. L. Andrew ◽  
A. L. O'Neill
Keyword(s):  
Sea Urchin ◽  
Geographical Information Systems ◽  
Large Scale ◽  
Size Structure ◽  
New South ◽  
New South Wales ◽  
Geographical Information ◽  
South Wales ◽  
Subtidal Rocky Reefs ◽  
A Site

Aerial photography was used to estimate the representation of shallow subtidal habitats in New South Wales. Sixty sites, each between 4 and 5 hectares, were mapped with Geographical Information Systems software using ortho-rectified images digitized from 1:8000-scale photographs and ‘ground truthed’ in the field by divers. Barrens habitat covered an estimated 50% (s.e. = 3.9) of nearshore reefs between Port Stephens and Disaster Bay. Coverage of barrens habitat was greatest in Disaster Bay (68%, s.e. = 6.7) and least south of Disaster Bay (1%, s.e. = 0.3). There were clear differences among localities in the area of reef within the mapped sites; those at Cape Howe, Nadgee, and Turingal were significantly smaller in area than all others. There was no clear latitudinal trend in these differences but there was evidence of sand inundation at a site at Nadgee, where the reef was small. Differences in the densities and size-structure of the sea urchin Centrostephanus rodgersiiat 27 of the mapped sites provide a basis for testing relationships between the demography of this species and the persistence of the barrens habitat. The extensive coverage of the barrens habitat in New South Wales is likely to limit the productivity of the abalone industry. The development of a sea urchin fishery may have large impacts on habitat representation on nearshore reefs.

Some factors affecting the extraction of soil 'available' phosphate

Soil Research ◽  
1978 ◽  
Vol 16 (3) ◽  
pp. 355
Author(s):  
GD Batten
Keyword(s):  
Soil Solution ◽  
New South ◽  
New South Wales ◽  
Large Vessel ◽  
Soil Tests ◽  
Factors Affecting ◽  
Laboratory Error ◽  
South Wales ◽  
Available Phosphate

Twenty soils from southern New South Wales were analysed for acid extractable phosphate in 1971, and again in 1977 when it was found that an increase had occurred. These same samples were also analysed using reciprocating shakers with different distances of travel. More phosphate was extracted when a shaker with a greater distance of travel was used and when more soil, but at the same soil : solution ratio, was placed in a large vessel. It is suggested that such variations in technique contribute to inter-laboratory error in soil tests for phosphate.

Factors affecting pre-weaning growth and weaning conformation of Angus cattle

1978 ◽  
Vol 29 (2) ◽  
pp. 359
Author(s):  
R Barlow ◽  
EB Dettmann ◽  
LG Williams
Keyword(s):  
Least Squares ◽  
New South ◽  
Average Daily Gain ◽  
Factors Affecting ◽  
Angus Cattle ◽  
South Wales ◽  
Weaning Age ◽  
Males And Females ◽  
Main Effects ◽  
Daily Gain

Weaning weight (ww) and conformation score (cs) records from Angus calves in five New South Wales herds were analysed by least-squares procedures to assess the nature and magnitude of variation. Herd, year, age of dam and sex were considered as main effects. Covariates included in the models were weaning age (WA) for ww and average daily gain (ADG), and both WA and ww for cs. Male calves (steers and bulls) were 16.6 kg heavier at weaning than female calves. Dams that were 5-8 years of age weaned calves that were 30.1 kg, 15.4 kg and 6.7 kg heavier than 2-, 3- and 4-year-old dams respectively. When ww was not included as a covariate in the model, age of dam effects on cs reflected those on ww, and there was little difference in cs between males and females. When adjusted for differences in ww, males had poorer cs than females, and calves from 3-year-old dams, and from dams over 8 years old, had poorer cs than those from dams of all other ages. Partial regressions of ww and ADG on WA, and of cs on ww, varied considerably between herd/year/sex subgroups.

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