Seasonal range variation of Tadarida australis (Chiroptera:Molossidae) in Western Australia: the impact of enthalpy

2005 ◽  
Vol 53 (3) ◽  
pp. 145 ◽  
Author(s):  
R. D. Bullen ◽  
N. L. McKenzie
Keyword(s):  
Western Australia ◽  
Annual Rainfall ◽  
Limiting Factor ◽  
Range Limit ◽  
Potential Predator ◽  
Continental Scale ◽  
Summer Range ◽  
Potential Competitor ◽  
Tight Correlation ◽  
The Impact

The Australian bat Tadarida australis has a peculiar geographical niche that involves a continental-scale movement of over 10° of latitude in Western Australia. Its range expands northward by up to 1200 km for the winter and contracts southward for the summer. Its summer range limit correlates with an interaction of temperature and humidity, best summarised by atmospheric enthalpy. Its winter distribution is expanded northward within the enthalpy threshold, but appears to be further restricted in some areas by an unknown factor that may be biotic. We propose a potential competitor and a potential predator that may have strongly negative interactions in these regions. The 1% of records that are beyond the enthalpy envelope are from the change-over months and may be an artefact of year-to-year climatic variation. Three climatic thresholds enclose the enthalpy envelope: average annual rainfall >10 mm per month and <50 mm per month, and average overnight minimum temperature <20°C. Current literature relates migration of temperate-zone bats to resource availability as a consequence of changing season. We identify a tight correlation with atmospheric enthalpy that points to dissipation of flight muscle heat as a limiting factor.

scholarly journals Using trophic flows and ecosystem structure to model the effects of fishing in the Jurien Bay Marine Park, temperate Western Australia

2011 ◽  
Vol 62 (5) ◽  
pp. 421 ◽  
Author(s):  
Hector M. Lozano-Montes ◽  
Neil R. Loneragan ◽  
Russell C. Babcock ◽  
Kelsie Jackson
Keyword(s):  
Western Australia ◽  
Negative Impact ◽  
Limiting Factor ◽  
Commercial Fishing ◽  
Ecosystem Structure ◽  
Fishing Mortality ◽  
Benthic Primary Production ◽  
Cascading Effects ◽  
Marine Park ◽  
The Impact

Understanding the impacts of fishing on the trophic structure of systems has become increasingly important because of the introduction of Ecosystem Based Fisheries Management and the legislative requirements of fisheries to demonstrate that they are not having a negative impact on other species. A biomass-based dynamic model of Jurien Bay Marine Park (∼30°S) was constructed using Ecopath to investigate the ecosystem impacts of fishing (mainly commercial rock lobster, Panulirus cygnus) in the park, as an example of the potential responses of temperate marine ecosystems in Western Australia to commercial fishing. A simulated 50% reduction in fishing mortality for commercial finfish predicted that after 20 years, the biomass of important fished species (i.e. Pagrus auratus and Choerodon rubescens) would increase by up to 30%. A simulated total fishing closure resulted in much larger (2.5–8 fold) increases in targeted populations, but did not result in any predicted cascading effects on grazing invertebrates and benthic primary producers. The simulations suggest that the structure of this ecosystem is characterised more by bottom-up than top-down processes; i.e. benthic primary production is a major limiting factor. The present study identified trophic linkages and ecosystem processes such as the role of both low and high trophic-level groups and the impact of fishing mortality in the marine park, an essential step towards distinguishing the impacts of fishing from those attributable to natural or other human-induced changes.

scholarly journals The Impact of Climate Change on Farm Business Performance in Western Australia

2021 ◽  
Vol 15 ◽  
pp. 32-37
Author(s):  
L. Anderton ◽  
R. Kingwell ◽  
D. Feldman ◽  
J. Speijers ◽  
N. Islam ◽  
...  
Keyword(s):  
Western Australia ◽  
Business Performance ◽  
Growing Season ◽  
Annual Rainfall ◽  
Multidisciplinary Study ◽  
Behavioural Characteristics ◽  
Farm Operators ◽  
Maximum Temperatures ◽  
Farm Business ◽  
The Impact

This study examines ten years of financial and production data of 249 farm businesses operating in southwestern Australia. It also identifies the behavioural characteristics of the farm operators through a comprehensive socio-managerial survey of each farm business. The study area has a Mediterranean climate, where three quarters of the rainfall is received during the growing season from April and October. Growers have learned to produce 2 tonnes per hectare of wheat on less than 200 ml of growing season rainfall. Australia is the driest continent in the world and is renowned for its climate variability. In addition, evidence is emerging that its southern parts, like south-western Australia, are experiencing a warming, drying trend in their climate. Average annual rainfall over the last thirty years in the study area has declined and average minimum and maximum temperatures have risen. Moreover, in the last ten years a number of droughts have occurred. This multidisciplinary study examines the business performance of 249 farms from 2002 to 2011 and identifies the strategies farm managers have adopted to adapt to a drying, warming environment. Farms are categorised according to their performance. Their characteristics are compared and contrasted. We find many significant differences between farm performance categories and the adaptation strategies used by the farmers in each category. There are also different socio-managerial and behavioural characteristics between the groups of farmers identified.

Impact of changing rainfall conditions on surface and groundwater resources in an experimental watershed in Greece

2013 ◽  
Vol 12 (2) ◽  
pp. 119-125
Keyword(s):  
Groundwater Resources ◽  
Annual Runoff ◽  
Annual Rainfall ◽  
Rainfall Regime ◽  
Winter Rainfall ◽  
Rainfall Depth ◽  
Rainfall Volume ◽  
The Mean ◽  
Groundwater Reserves ◽  
The Impact

The present study concerns the impact of a change in the rainfall regime on surface and groundwater resources in an experimental watershed. The research is conducted in a gauged mountainous watershed (15.18 km2) that is located on the eastern side of Penteli Mountain, in the prefecture of Attica, Greece and the study period concerns the years from 2003 to 2008. The decrease in the annual rainfall depth during the last two hydrological years 2006-2007, 2007-2008 is 10% and 35%, respectively, in relation to the average of the previous years. In addition, the monthly distribution of rainfall is characterized by a distinct decrease in winter rainfall volume. The field measurements show that this change in rainfall conditions has a direct impact on the surface runoff of the watershed, as well as on the groundwater reserves. The mean annual runoff in the last two hydrological years has decreased by 56% and 75% in relation to the average of the previous years. Moreover, the groundwater level follows a declining trend and has dropped significantly in the last two years.

The Constitutional Identity of European Micro States and the Continental Integration Mechanisms. The Influence of the Diminutive Size

ICL Journal ◽  
2020 ◽  
Vol 14 (2) ◽  
pp. 133-165
Author(s):  
Elisa Bertolini
Keyword(s):  
Foreign Relations ◽  
Council Of Europe ◽  
Continental Scale ◽  
National Tradition ◽  
Relevant Role ◽  
Integration Mechanisms ◽  
Traditional Institutions ◽  
The Impact ◽  
Constitutional Identity ◽  
The Eu

AbstractThe article analyses the impact that the diminutive size of the four continental Europe micro states has upon their constitutional arrangements and their approach toward continental integration mechanisms. Generally speaking, the international commitment toward integration mechanisms is one of the distinguishing traits of micro states. It may seem a paradox, but actually the international dimension is much more strategic for micro than for macro states. However, being micro territorial enclaves demanded certain ability from the part of European micro states when managing foreign relations in order not to be swallowed by their macro neighbours. Therefore, they carried out for centuries a cautious policy of ‘guarded openness’, trying to strike a balance between the maintenance of their traditional institutions and the need to interact on a continental scale. Constitutional systems that at a first glance are unusual may be an obstacle to integration and thus have to be reformed. However, not too much, because otherwise the whole system may implode if deprived of its original constitutional balance. The protection of national tradition and identity is conservative, in the sense that it arises from the necessity of self-preservation, rather than from ideology. The article claims that the ambivalent approach of continental Europe micro states have when interacting with macro states within the Council of Europe and the EU directly derives from their diminutive size. Furthermore, the relevant role played by the diminutive size is proved by the fact that recently the EU adopted a specific micro states approach. Hence, the article also aims at investigating how they try to strike a balance between the commitment toward self-preservation – ie their constitutional identity – and the commitment toward continental integration mechanisms.

scholarly journals The impact of monetary incentives on general fertility rates in Western Australia

2010 ◽  
Vol 66 (4) ◽  
pp. 296-301 ◽  
Author(s):  
Amanda T Langridge ◽  
Natasha Nassar ◽  
Jianghong Li ◽  
Peter Jacoby ◽  
Fiona J Stanley
Keyword(s):  
Western Australia ◽  
Monetary Incentives ◽  
Fertility Rates ◽  
The Impact

The impact of three species of Mycosphaerella newly recorded on Eucalyptus in Western Australia

1997 ◽  
Vol 26 (2) ◽  
pp. 71 ◽  
Author(s):  
A.J. Carnegie ◽  
P. J. Keane ◽  
F. D. Podger
Keyword(s):  
Western Australia ◽  
The Impact

Fire, people and ecosystem change in Pleistocene Australia

2016 ◽  
Vol 64 (8) ◽  
pp. 643 ◽  
Author(s):  
Christopher N. Johnson
Keyword(s):  
Fire Regimes ◽  
Ecosystem Change ◽  
Future Research ◽  
Cascading Effects ◽  
Continental Scale ◽  
The Past ◽  
The 1960S ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

Since the 1960s, Australian scientists have speculated on the impact of human arrival on fire regimes in Australia, and on the relationship of landscape fire to extinction of the Pleistocene megafauna of Australia. These speculations have produced a series of contrasting hypotheses that can now be tested using evidence collected over the past two decades. In the present paper, I summarise those hypotheses and review that evidence. The main conclusions of this are that (1) the effects of people on fire regimes in the Pleistocene were modest at the continental scale, and difficult to distinguish from climatic controls on fire, (2) the arrival of people triggered extinction of Australia’s megafauna, but fire had little or no role in the extinction of those animals, which was probably due primarily to hunting and (3) megafaunal extinction is likely to have caused a cascade of changes that included increased fire, but only in some environments. We do not yet understand what environmental factors controlled the strength and nature of cascading effects of megafaunal extinction. This is an important topic for future research.

scholarly journals Has erosion globally increased? Long-term erosion rates as a function of climate derived from the impact crater inventory

2018 ◽  
Author(s):  
Stefan Hergarten ◽  
Thomas Kenkmann
Keyword(s):  
Time Scale ◽  
Impact Crater ◽  
Regional Effect ◽  
Tropical Zone ◽  
Erosion Rates ◽  
Continental Scale ◽  
River Loads ◽  
The Impact

Abstract. Worldwide erosion rates seem to have increased strongly since the beginning of the Quaternary, but there is still discussion about the role of glaciation as a potential driver and even whether the increase is real at all or an artefact due to losses in the long-term sedimentary record. In this study we derive estimates of average erosion rates on the time scale of some tens of million years from the terrestrial impact crater inventory. This approach is completely independent from all other methods to infer erosion rates such as river loads, preserved sediments, cosmogenic nuclides and thermochronometry. Our approach yields average erosion rates as a function of present-day topography and climate. The results confirm that topography accounts for the main part of the huge variation of erosion on Earth, but also identifies a significant systematic dependence on climate in contrast to several previous studies. We found a fivefold increase in erosional efficacy from the cold regimes to the tropical zone and that temperate and arid climates are very similar in this context. Combining our results to a worldwide mean erosion rate we found that erosion rates on the time scale of some tens of million years are at least as high as present-day rates and suggest that glaciation has a rather regional effect with a limited impact at the continental scale.

Syphilis epidemiology and public health interventions in Western Australia from 1991 to 2009

Sexual Health ◽  
2012 ◽  
Vol 9 (3) ◽  
pp. 272 ◽  
Author(s):  
Kellie S. H. Kwan ◽  
Carolien M. Giele ◽  
Heath S. Greville ◽  
Carole A. Reeve ◽  
P. Heather Lyttle ◽  
...  
Keyword(s):  
Public Health ◽  
Western Australia ◽  
Aboriginal People ◽  
Congenital Syphilis ◽  
The United States ◽  
Health Interventions ◽  
Public Health Interventions ◽  
Sex With Men ◽  
Notification Data ◽  
The Impact

Objectives To describe the epidemiology of congenital and infectious syphilis during 1991–2009, examine the impact of public health interventions and discuss the feasibility of syphilis elimination among Aboriginal people in Western Australia (WA). Methods: WA congenital and infectious syphilis notification data in 1991–2009 and national infectious syphilis notification data in 2005–2009 were analysed by Aboriginality, region of residence, and demographic and behavioural characteristics. Syphilis public health interventions in WA from 1991–2009 were also reviewed. Results: During 1991–2009, there were six notifications of congenital syphilis (50% Aboriginal) and 1441 infectious syphilis notifications (61% Aboriginal). During 1991–2005, 88% of notifications were Aboriginal, with several outbreaks identified in remote WA. During 2006–2009, 62% of notifications were non-Aboriginal, with an outbreak in metropolitan men who have sex with men. The Aboriginal : non-Aboriginal rate ratio decreased from 173 : 1 (1991–2005) to 15 : 1 (2006–2009). Conclusions: These data demonstrate that although the epidemiology of syphilis in WA has changed over time, the infection has remained endemic among Aboriginal people in non-metropolitan areas. Given the continued public health interventions targeted at this population, the limited success in eliminating syphilis in the United States and the unique geographical and socioeconomic features of WA, the elimination of syphilis seems unlikely in this state.

Sign in / Sign up

Export Citation Format

Share Document