scholarly journals The effect of changing land use on the availability of potential nest trees for the endangered Muir's corella (Cacatua pastinator pastinator): a case study of the establishment of commercial Tasmanian blue gum plantations in Western Australia

2015 ◽  
Vol 21 (2) ◽  
pp. 146
Author(s):  
P. R. Mawson ◽  
C. E. Cooper
Keyword(s):  
Western Australia ◽  
Rapid Development ◽  
Native Vegetation ◽  
Care Needs ◽  
Remnant Vegetation ◽  
South West ◽  
Large Numbers ◽  
Study Sites ◽  
Blue Gum

In the mid-1990s commercial Tasmanian blue gum (Eucalyptus globulus) plantations were established in south-west Western Australia. We examined the extent of loss of potential nesting trees for an endangered obligate hollow-nesting cockatoo, Muir’s corella (Cacatua pastinator pastinator), resulting from establishment of these plantations during 1995–2004. Clearing of native vegetation was extensive in both Tonebridge (51%) and Frankland (76%) study sites. The proportion of land used for timber plantation increased significantly from 2.4% to 12.1% (Tonebridge) and 0.5% to 9% (Frankland) in the period 1995–2004. Plantations were predominantly established on already cleared farmland, but during the rapid development of plantations, large numbers of remnant paddock trees (mean = 56%) in cleared farmland were removed. Despite the loss of more than 50% of potential nesting habitat over an area of 376km2 within its current distribution, Muir’s corella continued to increase in numbers. However, there are concerns about delayed impacts of the clearing of potential nest trees we have observed, and consequences of further tree loss during future plantation harvesting. Evidence-based demonstration of biodiversity protection is increasingly needed to fulfil forest and plantation stewardship requirements, so greater care needs to be directed towards the management of extant remnant vegetation in paddocks.

The European Rabbit in South-Western Australia. I. Study Sites and Population Dynamics.

1985 ◽  
Vol 12 (2) ◽  
pp. 183 ◽  
Author(s):  
DR King ◽  
SH Wheeler
Keyword(s):  
Biological Control ◽  
Western Australia ◽  
Biological Control Agent ◽  
Control Agent ◽  
European Rabbit ◽  
Breeding Period ◽  
South West ◽  
Study Sites ◽  
Breeding Seasons ◽  
Winter Rain

Descriptions are given of 2 study sites in the south-west of Western Australia, on which rabbit numbers were monitored. Breeding seasons began in March or April, with the onset of winter rain, and rabbit numbers peaked in October-December, followed by a fall over the non-breeding period in summer. Winter epizootics of myxomatosis, which were spread by Spilopsyllus cuniculi, caused severe declines in rabbit numbers at both sites. Summer epizootics at one site before the introduction of the flea as a biological control agent, and rabbit mortality during these, was lower than in the winter epizootics.

Salinisation and prospects for biodiversity in rivers and wetlands of south-west Western Australia

2003 ◽  
Vol 51 (6) ◽  
pp. 673 ◽  
Author(s):  
S. A. Halse ◽  
J. K. Ruprecht ◽  
A. M. Pinder
Keyword(s):  
Western Australia ◽  
Aquatic Ecosystems ◽  
Saline Water ◽  
Biological Communities ◽  
Invertebrate Species ◽  
South West ◽  
Large Numbers ◽  
High Concentrations ◽  
Water Volumes ◽  
Western Australian

Saline water was common in south-west Western Australian aquatic systems prior to land-clearing because most streams and wetlands were ephemeral and evapo-concentrated as they dried, and there were high concentrations of stored salt in groundwater and soil profiles. Nevertheless, a 1998 review of salinity trends in rivers of south-west Western Australia showed that 20-fold increases in salinity concentrations had occurred since clearing in the medium-rainfall zone (300–700 mm). More recent data confirm these trends and show that elevated salinities have already caused substantial changes to the biological communities of aquatic ecosystems. Further substantial changes will occur, despite the flora and fauna of the south-west being comparatively well adapted to the presence of salinity in the landscape. Up to one-third of wetland and river invertebrate species, large numbers of plants and a substantial proportion of the waterbird fauna will disappear from the wheatbelt, a region that has high biodiversity value and endemism. Increased salinities are not the only threat associated with salinisation: increased water volumes, longer periods of inundation and more widespread acidity are also likely to be detrimental to the biota.

scholarly journals COVID-19 vaccine prioritisation to the groups with the most interactions can substantially reduce total fatalities

2020 ◽  
Author(s):  
Jorge Rodríguez ◽  
Mauricio Patón ◽  
Juan M Acuña
Keyword(s):  
Compartmental Model ◽  
Rapid Development ◽  
Population Coverage ◽  
Health Authorities ◽  
Age Related ◽  
Large Numbers ◽  
Vaccine Distribution ◽  
Open Question ◽  
Short Time

SummaryBackgroundThe unprecedented rapid development of vaccines against the SARS-CoV-2 virus creates in itself a new challenge for governments and health authorities: the effective vaccination of large numbers of people in a short time and, possibly, with shortage of vaccine doses. To whom vaccinate first and in what sequence, if any at all, to avoid the most fatalities remains an open question.MethodsA compartmental model considering age-related groups was developed to evaluate and compare vaccine distribution strategies in terms of the total avoidable fatalities. Population groups are established based on relevant differences in mortality (due to e.g. their age) and risk-related traits (such as their behaviour and number of daily person-to-person interactions). Vaccination distribution strategies were evaluated for different vaccine effectiveness levels and population coverage in a case study for Spain.FindingsOur results unambiguously show that planning vaccination by priority groups can achieve dramatic reductions in total fatalities compared to no prioritisation. Our results also indicate that the best strategy for vaccine distributions appears to be to prioritise groups with the highest number of daily person-to-person interactions. This is due to the importance of the avoided subsequent infections inflicted on the rest of the population by those in those groups.InterpretationThese results are in direct contradiction with several published guidelines for COVID-19 vaccination and therefore highlight the importance of conducting an open comprehensive and thorough analysis of this problem leaving behind possible preconceptions.

Control charts for improved decisions in environmental management: a case study of catchment water supply in south-west Western Australia

2013 ◽  
Vol 14 (2) ◽  
pp. 127-134 ◽  
Author(s):  
Aaron D. Gove ◽  
Rohan Sadler ◽  
Mamoru Matsuki ◽  
Robert Archibald ◽  
Stuart Pearse ◽  
...  
Keyword(s):  
Environmental Management ◽  
Water Supply ◽  
Western Australia ◽  
Control Charts ◽  
South West

The conservation value of private property; a case study of the birds of Woopenatty, Arrino, in the northern wheatbelt of Western Australia, 1987–2002.

2012 ◽  
Vol 18 (3) ◽  
pp. 164 ◽  
Author(s):  
Denis A Saunders ◽  
A J McAleer
Keyword(s):  
Western Australia ◽  
Private Property ◽  
Bird Species ◽  
Native Vegetation ◽  
Property A ◽  
Weekly Basis ◽  
Biogeographic Region ◽  
Changes Over Time ◽  
Conservation And Management

Woopenatty was a 7,293 ha wheat-sheep property in the Geraldton Sandplains biogeographic region of the northern wheatbelt of Western Australia. Data were collected on the presence of bird species seen on a weekly basis on the property from October 1987 until the end of 2002. A total of 133 species was recorded from the property during this period with 52 species of resident, 16 species of regular visitor, 15 species of irregular visitor and 50 vagrant species. The avifauna of the property was compared with records collated from 1904 from eight locations within a radius of 110 km of the property and from records within a radius of 50 km of the property from two Birds Australia atlases (1977– 1981 and 1997–2002). Seventy-four percent of the species, including many dependent on remnant native vegetation, recorded from the other localities were recorded on Woopenatty. The property was clearly of importance for conservation of the avifauna of the Geraldton Sandplains. This study illustrates the importance of publishing descriptions of regional biota in order to assess changes over time and the significance of remnant native vegetation on private property to conservation. Suggestions for setting priorities for conservation and management of such remnant native vegetation are made.

scholarly journals Modelling the effects of climate and land cover change on groundwater recharge in south-west Western Australia

2012 ◽  
Vol 16 (8) ◽  
pp. 2709-2722 ◽  
Author(s):  
W. Dawes ◽  
R. Ali ◽  
S. Varma ◽  
I. Emelyanova ◽  
G. Hodgson ◽  
...  
Keyword(s):  
Land Cover ◽  
Groundwater Recharge ◽  
Western Australia ◽  
Coastal Plain ◽  
Future Climate ◽  
Native Vegetation ◽  
Groundwater Levels ◽  
Swan Coastal Plain ◽  
South West ◽  
Recharge Rates

Abstract. The groundwater resource contained within the sandy aquifers of the Swan Coastal Plain, south-west Western Australia, provides approximately 60 percent of the drinking water for the metropolitan population of Perth. Rainfall decline over the past three decades coupled with increasing water demand from a growing population has resulted in falling dam storage and groundwater levels. Projected future changes in climate across south-west Western Australia consistently show a decline in annual rainfall of between 5 and 15 percent. There is expected to be a reduction of diffuse recharge across the Swan Coastal Plain. This study aims to quantify the change in groundwater recharge in response to a range of future climate and land cover patterns across south-west Western Australia. Modelling the impact on the groundwater resource of potential climate change was achieved with a dynamically linked unsaturated/saturated groundwater model. A vertical flux manager was used in the unsaturated zone to estimate groundwater recharge using a variety of simple and complex models based on climate, land cover type (e.g. native trees, plantation, cropping, urban, wetland), soil type, and taking into account the groundwater depth. In the area centred on the city of Perth, Western Australia, the patterns of recharge change and groundwater level change are not consistent spatially, or consistently downward. In areas with land-use change, recharge rates have increased. Where rainfall has declined sufficiently, recharge rates are decreasing, and where compensating factors combine, there is little change to recharge. In the southwestern part of the study area, the patterns of groundwater recharge are dictated primarily by soil, geology and land cover. In the sand-dominated areas, there is little response to future climate change, because groundwater levels are shallow and much rainfall is rejected recharge. Where the combination of native vegetation and clayey surface soils restricts possible infiltration, recharge rates are very sensitive to reductions in rainfall. In the northern part of the study area, both climate and land cover strongly influence recharge rates. Recharge under native vegetation is minimal and is relatively higher where grazing and pasture systems have been introduced after clearing of native vegetation. In some areas, the recharge values can be reduced to almost zero, even under dryland agriculture, if the future climate becomes very dry.

scholarly journals Modelling the effects of climate and land cover change on groundwater recharge in south-west Western Australia

2012 ◽  
Vol 9 (5) ◽  
pp. 6063-6099 ◽  
Author(s):  
W. Dawes ◽  
R. Ali ◽  
S. Varma ◽  
I. Emelyanova ◽  
G. Hodgson ◽  
...  
Keyword(s):  
Land Cover ◽  
Groundwater Recharge ◽  
Western Australia ◽  
Coastal Plain ◽  
Groundwater Resource ◽  
Annual Rainfall ◽  
Native Vegetation ◽  
Groundwater Levels ◽  
Swan Coastal Plain ◽  
South West

Abstract. The groundwater resource contained within the sandy aquifers of the Swan Coastal Plain, south west Western Australia, provides approximately 60% of the drinking water for the metropolitan population of Perth. Rainfall decline over the past three decades coupled with increasing water demand from a growing population has resulted in falling dam storage and groundwater levels. Projected future changes in climate across south-west Western Australia consistently show a decline in annual rainfall of between 5 and 15%. There is expected to be a continuing reduction of diffuse recharge across the Swan Coastal Plain. This study aims to quantify the change in groundwater recharge in response to a range of future climate and land cover patterns across south-west Western Australia. Modelling the impact on the groundwater resource of potential climate change was achieved with a dynamically linked unsaturated/saturated groundwater model. A Vertical Flux Manager was used in the unsaturated zone to estimate groundwater recharge using a variety of simple and complex models based on land cover type (e.g. native trees, plantation, cropping, urban, wetland), soil type, and taking into account the groundwater depth. These recharge estimates were accumulated on a daily basis for both observed and projected climate scenarios and used in a MODFLOW simulation with monthly stress periods. In the area centred on the city of Perth, Western Australia, the patterns of recharge change and groundwater level change are not consistent spatially, or consistently downward. In the Dandaragan Plateau to the north-east of Perth there has been groundwater level rise since the 1970s associated with land clearing, and with rainfall projected to reduce the least in this area the groundwater levels are estimated to continue to rise. Along the coastal zone north of Perth there is an interaction between projected rainfall decline and legislated removal to pine forests. This results in areas of increasing recharge and rising water levels into the future despite a drying climate signal. To the south of Perth city there are large areas where groundwater levels are close to the land surface and not expected to change more than 1m upward or downward over the next two decades; it is beyond the accuracy of the model to conclude any definite trend. In the south western part of the study area, the patterns of groundwater recharge are dictated primarily by soil, geology and land cover. In the sandy Swan (northern boundary) and Scott Coastal Plains (southern boundary) there is little response to future climates, because groundwater levels are shallow and much rainfall is rejected recharge. The profile dries out more in summer but this allows more rainfall to infiltrate in winter. Until winter recharge is insufficient to refill the aquifers these areas will not experience significant falls in groundwater levels. On the Blackwood Plateau however, the combination of native vegetation and clayey surface soils that restrict possible infiltration and recharge mean the area is very sensitive to climate change. With low capacity for recharge and low storage in the aquifers, small reductions in recharge can lead to large reductions in groundwater levels. In the northern part of the study area both climate and land cover strongly influence recharge rates. Recharge under native vegetation is minimal and is relatively higher where grazing and pasture systems have been introduced after clearing of native vegetation. In some areas the low recharge values can be reduced to almost zero, even under dryland agriculture, if the future climate becomes very dry. In the Albany Area the groundwater resource is already over allocated, and the combination of existing permanent native vegetation with decreasing annual rainfall indicate reduced recharge. The area requires a reduction in groundwater abstraction to maintain the sustainability of the existing resource.

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