Differences in trap-finding behaviour of two populations of Austrosimulium bancrofti (Taylor) (Diptera: Simuliidae) in eastern Australia

1990 ◽  
Vol 68 (3) ◽  
pp. 579-584 ◽  
Author(s):  
J. W. O. Ballard ◽  
K. J. Morton
Keyword(s):  
Carbon Dioxide ◽  
Wind Speed ◽  
Environmental Conditions ◽  
Host Finding ◽  
Time Of Day ◽  
Host Preferences ◽  
Eastern Australia ◽  
Two Populations

Three carbon dioxide baited silhouette traps of different shape and an animal-baited trap were used to evaluate trap- and host-finding behaviour of Austrosimulium bancrofti (Taylor) at two locations in eastern Australia. Highly significant effects influencing silhouette-trap-finding were incorporated into models that generated estimates of the numbers of flies captured under defined conditions. Estimates indicated that the effects of trap shape, hour after sunrise, experimental day, temperature, and wind speed differed at each location. Acclimation to local environmental conditions may explain differences in the silhouette trapping data, but the effects of trap shape and perhaps time of day were more difficult to explain. Austrosimulium bancrofti were attracted to bovines at both locations, whereas humans, bandicoots, and chickens were not attractive. It will be necessary to test a wider range of bait species before the host preferences of A. bancrofti at these locations can be determined.

scholarly journals Environmental conditions are poor predictors of immature white shark Carcharodon carcharias occurrences on coastal beaches of eastern Australia

2020 ◽  
Vol 653 ◽  
pp. 167-179
Author(s):  
JLY Spaet ◽  
A Manica ◽  
CP Brand ◽  
C Gallen ◽  
PA Butcher
Keyword(s):  
Environmental Conditions ◽  
Prey Availability ◽  
Statistical Significance ◽  
Time Of Day ◽  
White Shark ◽  
Additive Models ◽  
Large Sample Size ◽  
Lunar Phase ◽  
Carcharodon Carcharias ◽  
Eastern Australia

Understanding and predicting the distribution of organisms in heterogeneous environments is a fundamental ecological question and a requirement for sound management. To implement effective conservation strategies for white shark Carcharodon carcharias populations, it is imperative to define drivers of their movement and occurrence patterns and to protect critical habitats. Here, we acoustically tagged 444 immature white sharks and monitored their presence in relation to environmental factors over a 3 yr period (2016-2019) using an array of 21 iridium satellite-linked (VR4G) receivers spread along the coast of New South Wales, Australia. Results of generalized additive models showed that all tested predictors (month, time of day, water temperature, tidal height, swell height, lunar phase) had a significant effect on shark occurrence. However, collectively, these predictors only explained 1.8% of deviance, suggesting that statistical significance may be rooted in the large sample size rather than biological importance. On the other hand, receiver location, which captures geographic fidelity and local conditions not captured by the aforementioned environmental variables, explained a sizeable 17.3% of deviance. Sharks tracked in this study hence appear to be tolerant to episodic changes in environmental conditions, and movement patterns are likely related to currently undetermined, location-specific habitat characteristics or biological components, such as local currents, prey availability or competition. Importantly, we show that performance of VR4G receivers can be strongly affected by local environmental conditions, and provide an example of how a lack of range test controls can lead to misinterpretation and erroneous conclusions of acoustic detection data.

Maximum radius of carbon dioxide baited trap impact in woodland: implications for host-finding by mosquitoes

Biologia ◽  
2014 ◽  
Vol 69 (4) ◽  
Author(s):  
Željka Marinković ◽  
Branimir Hackenberger ◽  
Enrih Merdić
Keyword(s):  
Carbon Dioxide ◽  
Wind Speed ◽  
Wind Velocity ◽  
Plant Community ◽  
Maximum Concentration ◽  
Host Finding ◽  
Forest Habitat ◽  
Maximum Radius ◽  
Maximum Range ◽  
Optimal Radius

AbstractCDC traps were used to determine the maximum radius of carbon dioxide attraction within forest habitat (a forest plant community with Carpino betuli-Quercetum roburis). A central CDC trap with dry ice (CO2) was set as the source of attractant (Ck). Around Ck trap two circles (A and B) of CDC traps without attractants were placed. Circle A was constituted of 6 CDC traps and Circles B with 12 CDC traps. Radius from Circle A and B to the Ck trap were used to determine CO2 maximum range. During the experiment, the average emissions of CO2 were 0.08 to 0.1 g s−1. Regarding the data, optimal radius attraction where CO2 was affected on mosquitoes was between 55 and 70 m from the source. Results propose that the distance between traps should be greater than 140 m, to ensure the absence of bias by each of the traps. Changes in CO2 maximum concentration and wind velocity directly affected the catch of different species. The number of Ochlerotatus sticticus collected was positively correlated with wind speed.

scholarly journals The Application of Visual Environmental Economics in the Study of Public Preference and Urban Greenspace

2009 ◽  
Vol 36 (2) ◽  
pp. 355-375 ◽  
Author(s):  
Richard Laing ◽  
Anne-Marie Davies ◽  
David Miller ◽  
Anna Conniff ◽  
Stephen Scott ◽  
...  
Keyword(s):  
Environmental Economic ◽  
Environmental Economics ◽  
Environmental Conditions ◽  
Three Dimensional ◽  
Computer Models ◽  
Time Of Day ◽  
Public Preference ◽  
Daily Lives ◽  
Urban Greenspace ◽  
Physical Variables

Urban greenspace has consistently been argued to be of great importance to the wellbeing, health, and daily lives of residents and users. This paper reports results from a study that combined the visualisation of public results from a study that combined the visualisation of public greenspace with environmental economics, and that aimed to develop a method by which realistic computer models of sites could be used within preference studies. As part of a methodology that employed contingent rating to establish the values placed on specific greenspace sites, three-dimensional computer models were used to produce visualisations of particular environmental conditions. Of particular importance to the study was the influence of variables including lighting, season, time of day, and weather on the perception of respondents. This study followed previous work that established a suitable approach to the modelling and testing of entirely moveable physical variables within the built environment. As such, the study has established firmly that computer-generated visualisations are appropriate for use within environmental economic surveys, and that there is potential for a holistic range of attributes to be included in such studies.

scholarly journals Carbon dioxide fluxes increase from day to night across European streams

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Katrin Attermeyer ◽  
Joan Pere Casas-Ruiz ◽  
Thomas Fuss ◽  
Ada Pastor ◽  
Sophie Cauvy-Fraunié ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Large Scale ◽  
Carbon Dioxide Flux ◽  
Time Of Day ◽  
Night Time ◽  
Carbon Dioxide Fluxes ◽  
Large Scale Assessment ◽  
Air Interface ◽  
Flux Variability

AbstractGlobally, inland waters emit over 2 Pg of carbon per year as carbon dioxide, of which the majority originates from streams and rivers. Despite the global significance of fluvial carbon dioxide emissions, little is known about their diel dynamics. Here we present a large-scale assessment of day- and night-time carbon dioxide fluxes at the water-air interface across 34 European streams. We directly measured fluxes four times between October 2016 and July 2017 using drifting chambers. Median fluxes are 1.4 and 2.1 mmol m−2 h−1 at midday and midnight, respectively, with night fluxes exceeding those during the day by 39%. We attribute diel carbon dioxide flux variability mainly to changes in the water partial pressure of carbon dioxide. However, no consistent drivers could be identified across sites. Our findings highlight widespread day-night changes in fluvial carbon dioxide fluxes and suggest that the time of day greatly influences measured carbon dioxide fluxes across European streams.

scholarly journals Morphological variation in Leptorhynchos squamatus (Gnaphalieae: Asteraceae)

2002 ◽  
Vol 15 (2) ◽  
pp. 205 ◽  
Author(s):  
Christina Flann ◽  
Pauline Y. Ladiges ◽  
Neville G. Walsh
Keyword(s):  
High Altitude ◽  
Morphological Variation ◽  
Environmental Conditions ◽  
Leaf Size ◽  
Alpine Plants ◽  
The Other ◽  
Herbarium Specimens ◽  
South Eastern ◽  
Eastern Australia ◽  
Low Altitude

A study of morphological variation in Leptorhynchos squamatus (Labill.) Less. across its range in south-eastern Australia was undertaken to test the hypothesis that L. squamatus includes two taxa. Phenetic pattern analyses of both field-collected and herbarium specimens on the basis of morphology confirmed two major groups. Bract, cypsela, pappus bristle and leaf characters were particularly important in separating the two groups. The taxa are separated by altitude differences with one being a low-altitude plant found in many habitats and the other being a high-altitude taxon that is a major component of alpine meadows. Lowland plants have dark bract tips, fewer and wider pappus bristles than alpine plants, papillae on the cypselas and more linear leaves. A somewhat intermediate population from the Major Mitchell Plateau in the Grampians shows some alpine and some lowland characters but is included in the lowland taxon. Seeds from five populations (two alpine, two lowland and Major Mitchell) were germinated and plants grown for 18 weeks under four controlled sets of environmental conditions. The experiment showed that leaf size and some other characters are affected by environmental conditions, but that there are underlying genetic differences between the lowland and alpine forms. Leptorhynchos squamatus subsp. alpinus Flann is described here to accommodate the highland taxon.

Testing for Asymmetrical Gene Flow in aDrosophila melanogasterBody-Size Cline

Genetics ◽  
2003 ◽  
Vol 165 (2) ◽  
pp. 667-673 ◽  
Author(s):  
W Jason Kennington ◽  
Julia Gockel ◽  
Linda Partridge
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Flow ◽  
Body Size ◽  
Genetic Parameter ◽  
Good Evidence ◽  
Microsatellite Data ◽  
Eastern Australia ◽  
The Difference ◽  
Two Populations ◽  
Private Alleles

AbstractAsymmetrical gene flow is an important, but rarely examined genetic parameter. Here, we develop a new method for detecting departures from symmetrical migration between two populations using microsatellite data that are based on the difference in the proportion of private alleles. Application of this approach to data collected from wild-caught Drosophila melanogaster along a latitudinal body-size cline in eastern Australia revealed that asymmetrical gene flow could be detected, but was uncommon, nonlocalized, and occurred in both directions. We also show that, in contrast to the findings of a previous study, there is good evidence to suggest that the cline experiences significant levels of gene flow between populations.

Retrospective Genomics Suggests the Disappearance of a Tiger Shark (Galeocerdo Cuvier) Population Off South-Eastern Australia

2021 ◽  
Author(s):  
Alice Manuzzi ◽  
Belen Jiménez-Mena ◽  
Romina Henriques ◽  
Bonnie J. Holmes ◽  
Julian Pepperell ◽  
...  
Keyword(s):  
Anthropogenic Disturbance ◽  
East Coast ◽  
Tiger Shark ◽  
Galeocerdo Cuvier ◽  
Relative Contribution ◽  
Eastern Australia ◽  
Genomic Analyses ◽  
Dramatic Shift ◽  
Well Differentiated ◽  
Two Populations

Abstract Over the last century, many populations of sharks have been reduced in numbers by overexploitation or attempts to mitigate human-shark interactions. Still, there is a general perception that populations of large ocean predators cover wide areas and therefore their diversity is less susceptible to local anthropogenic disturbance. Here we report retrospective genomic analyses of DNA using archived and contemporary samples of tiger shark (Galeocerdo cuvier) from eastern Australia. Using SNP loci, we documented a significant overall change in genetic composition of tiger sharks born over the last century. The change was most likely due to a shift over time in the relative contribution of two well differentiated, but hitherto cryptic populations. Our data strongly indicate a dramatic shift in relative contribution of the two populations to the overall tiger shark abundance of the east coast of Australia, possibly associated with differences in direct or indirect exploitation rates.

scholarly journals Low-level jets and above-canopy drainage as causes of turbulent exchange in the nocturnal boundary layer

2014 ◽  
Vol 11 (16) ◽  
pp. 4507-4519 ◽  
Author(s):  
T. S. El-Madany ◽  
H. F. Duarte ◽  
D. J. Durden ◽  
B. Paas ◽  
M. J. Deventer ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Wind Speed ◽  
Eddy Covariance ◽  
Latent Heat ◽  
Heat Fluxes ◽  
Vertical Wind ◽  
Sensible Heat ◽  
Intermittent Turbulence ◽  
Low Level Jets ◽  
Vertical Wind Velocity

Abstract. Sodar (SOund Detection And Ranging), eddy-covariance, and tower profile measurements of wind speed and carbon dioxide were performed during 17 consecutive nights in complex terrain in northern Taiwan. The scope of the study was to identify the causes for intermittent turbulence events and to analyze their importance in nocturnal atmosphere–biosphere exchange as quantified with eddy-covariance measurements. If intermittency occurs frequently at a measurement site, then this process needs to be quantified in order to achieve reliable values for ecosystem characteristics such as net ecosystem exchange or net primary production. Fourteen events of intermittent turbulence were identified and classified into above-canopy drainage flows (ACDFs) and low-level jets (LLJs) according to the height of the wind speed maximum. Intermittent turbulence periods lasted between 30 and 110 min. Towards the end of LLJ or ACDF events, positive vertical wind velocities and, in some cases, upslope flows occurred, counteracting the general flow regime at nighttime. The observations suggest that the LLJs and ACDFs penetrate deep into the cold air pool in the valley, where they experience strong buoyancy due to density differences, resulting in either upslope flows or upward vertical winds. Turbulence was found to be stronger and better developed during LLJs and ACDFs, with eddy-covariance data presenting higher quality. This was particularly indicated by spectral analysis of the vertical wind velocity and the steady-state test for the time series of the vertical wind velocity in combination with the horizontal wind component, the temperature, and carbon dioxide. Significantly higher fluxes of sensible heat, latent heat, and shear stress occurred during these periods. During LLJs and ACDFs, fluxes of sensible heat, latent heat, and CO2 were mostly one-directional. For example, exclusively negative sensible heat fluxes occurred while intermittent turbulence was present. Latent heat fluxes were mostly positive during LLJs and ACDFs, with a median value of 34 W m−2, while outside these periods the median was 2 W m−2. In conclusion, intermittent turbulence periods exhibit a strong impact on nocturnal energy and mass fluxes.

scholarly journals Predicting photosynthesis and transpiration responses to ozone: decoupling modeled photosynthesis and stomatal conductance

2012 ◽  
Vol 9 (8) ◽  
pp. 3113-3130 ◽  
Author(s):  
D. Lombardozzi ◽  
S. Levis ◽  
G. Bonan ◽  
J. P. Sparks
Keyword(s):  
Carbon Dioxide ◽  
Stomatal Conductance ◽  
Primary Productivity ◽  
Environmental Conditions ◽  
Water Exchange ◽  
Global Scale ◽  
Community Land Model ◽  
Climate Regulation ◽  
The Tropics ◽  
Tulip Poplar

Abstract. Plants exchange greenhouse gases carbon dioxide and water with the atmosphere through the processes of photosynthesis and transpiration, making them essential in climate regulation. Carbon dioxide and water exchange are typically coupled through the control of stomatal conductance, and the parameterization in many models often predict conductance based on photosynthesis values. Some environmental conditions, like exposure to high ozone (O3) concentrations, alter photosynthesis independent of stomatal conductance, so models that couple these processes cannot accurately predict both. The goals of this study were to test direct and indirect photosynthesis and stomatal conductance modifications based on O3 damage to tulip poplar (Liriodendron tulipifera) in a coupled Farquhar/Ball-Berry model. The same modifications were then tested in the Community Land Model (CLM) to determine the impacts on gross primary productivity (GPP) and transpiration at a constant O3 concentration of 100 parts per billion (ppb). Modifying the Vcmax parameter and directly modifying stomatal conductance best predicts photosynthesis and stomatal conductance responses to chronic O3 over a range of environmental conditions. On a global scale, directly modifying conductance reduces the effect of O3 on both transpiration and GPP compared to indirectly modifying conductance, particularly in the tropics. The results of this study suggest that independently modifying stomatal conductance can improve the ability of models to predict hydrologic cycling, and therefore improve future climate predictions.

scholarly journals An analysis of temperature distribution in solar photovoltaic module under various environmental conditions

2018 ◽  
Vol 240 ◽  
pp. 04004 ◽  
Author(s):  
Marek Jaszczur ◽  
Qusay Hassan ◽  
Janusz Teneta ◽  
Ewelina Majewska ◽  
Marcin Zych
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Wind Speed ◽  
Solar Radiation ◽  
Environmental Conditions ◽  
Operating Temperature ◽  
Photovoltaic Module ◽  
Solar Photovoltaic ◽  
System Efficiency ◽  
Pv System

The operating temperature of the photovoltaic module is an important issue because it is directly linked with system efficiency. The objective of this work is to evaluate temperature distribution in the photovoltaic module under different environmental conditions. The results shown that photovoltaic module operating temperature depends not only on the ambient temperature or solar radiation dependent but also depends on wind speed and wind direction. It is presented that the mounting conditions which are not taken into consideration by most of the literature models also play a significant role in heat transfer. Depends on mounting type an increase in module operating temperature in the range 10-15oC was observed which cause further PV system efficiency decrease of about 3.8-6.5 %.

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