scholarly journals Habitat Characteristics and Eggshell Distribution of the Salt Marsh Mosquito,Aedes vigilax, in Marshes in Subtropical Eastern Australia

2008 ◽  
Vol 8 (25) ◽  
pp. 1-8 ◽  
Author(s):  
Pat E. R. Dale ◽  
Jon Knight ◽  
Brian H. Kay ◽  
Heather Chapman ◽  
Scott A. Ritchie ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Habitat Characteristics ◽  
Aedes Vigilax ◽  
Eastern Australia

Distribution of the immature stages of Aedes vigilax on a coastal salt-marsh in south-east Queensland

1986 ◽  
Vol 11 (3) ◽  
pp. 269-278 ◽  
Author(s):  
P. E. R. DALE ◽  
K. HULSMAN ◽  
D. HARRISON ◽  
B. CONGDON
Keyword(s):  
Salt Marsh ◽  
Immature Stages ◽  
Coastal Salt Marsh ◽  
Aedes Vigilax

Polyploidy in Sporobolus virginicus (L.) Kunth

1979 ◽  
Vol 27 (4) ◽  
pp. 429 ◽  
Author(s):  
AR Smith-White
Keyword(s):  
Salt Marsh ◽  
Chromosome Number ◽  
Meiotic Division ◽  
Distribution Patterns ◽  
Meiotic Behaviour ◽  
Polyploid Complex ◽  
South Eastern ◽  
Sporobolus Virginicus ◽  
Eastern Australia ◽  
Tetraploid Cytotypes

Chromosome number and meiotic behaviour was examined in Sporobolus virginicus Kunth from south-eastern Australia. Var. minor Bail. forms a polyploid complex with diploid (2n = 20), triploid and tetraploid cytotypes. Meiosis in tetraploid plants of this variety is substantially normal, which indicates an alloploid origin. Var. virginicus, which has been found only in the tetraploid state, has irregular meiotic division, which suggests autoploidy. Most cytotypes were collected from sandy and well-drained situations along the coast. However, tetraploid var. minor plants were generally found in poorly aerated salt marsh swamps. This apparent edaphic adaption of tetraploid cytotypes may be important in explaining distribution patterns.

Biomass and above-ground productivity of salt-marsh plants in south-eastern Australia

1994 ◽  
Vol 45 (8) ◽  
pp. 1521 ◽  
Author(s):  
PJ Clarke ◽  
CA Jacoby
Keyword(s):  
Salt Marsh ◽  
Perennial Grass ◽  
Temporal Trends ◽  
Dry Weight ◽  
Spatial And Temporal Variation ◽  
Organic Carbon Content ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Sporobolus Virginicus ◽  
Eastern Australia

The above-ground biomass of three dominant salt-marsh vascular plants (Juncus kraussii, Sarcocornia quinquejlora and Sporobolus virginicus) was measured to assess both spatial and temporal variation and to provide baseline data. Additionally, the culm dynamics of the rush J. kraussii were measured so that aboveground productivity could be estimated. No distinct seasonal patterns were detected in above-ground biomass in J. kraussii. Averaged over all sites and times, the above-ground biomass of J. kraussii was 1116 g dry weight m-2. Culms are replaced annually, hence standing crop approximated annual above-ground productivity. Much of the dead aboveground biomass appears to accumulate in the upper marsh, as evidenced by the elevated nutrient and organic carbon content of the soil there relative to the sediment in the mangrove zone. Above-ground biomass of the decumbent perennial grass Sporobolus virginicus and the procumbent perennial chenopod Sarcocornia quinqueflora showed no consistent spatial or temporal trends. The above-ground standing crops of these species were about one-third that of J. kraussii.

Adaptive Variability in the Growth of Danthonia caespitosa Gaud. Populations at Different Temperatures

1976 ◽  
Vol 24 (3) ◽  
pp. 381 ◽  
Author(s):  
KC Hodgkinson ◽  
JA Quinn
Keyword(s):  
Growth Rates ◽  
Perennial Grass ◽  
Weight Ratio ◽  
Intraspecific Variability ◽  
Habitat Characteristics ◽  
Relative Growth Rates ◽  
The North ◽  
Eastern Australia ◽  
Different Temperatures ◽  
Net Assimilation

Five populations of the indigenous perennial grass Danthonia caespitosa Gaud. were selected from widely separated sites along a north-south transect in south-eastern Australia. The sites, spanning the latitudinal range (31° to 42° S.) for the species, extended from a hot semiarid environment in the north to a cool and moist temperate environment in the south. Two experiments, to assess the extent of intraspecific variability in response to different tempera- ture regimes, were conducted in naturally lit temperature-controlled glasshouses in the Ceres phyto- tron. All populations had a similar temperature optimum for growth of between 20.7 and 267°C (mean daily temperature), typical for temperate species. Rates of tillering, rates of leaf appearance, and leaf blade lengths and widths differed among populations and showed considerable phenotypic plasticity with respect to temperature. At all temperatures the growth rate of populations generally declined with increasing latitude of origin. A detailed analysis of growth rates showed that differences between populations in final weight could largely be accounted for by variability in mean relative growth rates. Northern populations in general had a higher net assimilation rate and leaf weight ratio than southern populations. The adaptive significance of these physiological and morphological differences between populations is discussed in relation to habitat characteristics and the distributional range of the species. It is concluded that along the latitudinal and climatic gradient there has been no significant change in temperature optima for growth but there has been natural selection resulting in higher growth rates of northern populations.

Dispersal patterns and population structure in a small marsupial, Antechinus agilis, from two forests analysed using microsatellite markers

2002 ◽  
Vol 50 (4) ◽  
pp. 325 ◽  
Author(s):  
F. J. L. Kraaijeveld-Smit ◽  
D. B. Lindenmayer ◽  
A. C. Taylor
Keyword(s):  
Population Structure ◽  
Isolation By Distance ◽  
Habitat Characteristics ◽  
Assignment Test ◽  
Dispersal Patterns ◽  
Genetic Structuring ◽  
Capture Site ◽  
Eastern Australia ◽  
Antechinus Agilis ◽  
One Year

Juvenile male agile antechinus (Antechinus agilis) are thought to disperse immediately after they leave the nest, whereas females are philopatric. However, no genetic data are available to support a hypothesis of male-biased dispersal, and the possible effects of habitat characteristics on dispersal are not known. We used five microsatellite loci to describe the dispersal patterns and population structure of A. agilis at two different forested sites (Mt Donna Buang and Mt Disappointment in central Victoria, south-eastern Australia). Within each site, DNA samples were collected from individuals from different trapping grids (four grids in Mt Donna Buang, collected over two years, and seven grids at Mt Disappointment, collected over one year). To assess levels of genetic structuring among the populations, Fst values (the proportion of genetic variance among populations) were calculated for each site and sex separately, and a test for isolation by distance was performed. Overall, Fst values were low, and did not increase with distance, and this may be the result of high levels of gene flow for both sexes at both sites, at least on the scale of less than 10 km. To investigate microsatellite patterns at a finer scale, we calculated pair-wise relatedness values separately for sites, years and sexes. By comparing these values for animals within and between grids, evidence was found for male-biased dispersal. A genetic assignment test provided further evidence for this: males were more likely to be assigned to grids other than their capture site. Most females had high assignment values for their capture site, although some of the females may have been immigrants. This result could be due to inaccuracies in the assignment test, or due to a higher frequency of dispersal of females than previously thought. The sex-biased dispersal was less pronounced at Mt Disappointment than at Mt Donna Buang. This may be related to the level of disturbance: logging patches, roads and fire-breaks (grass strips) disrupt the forest at Mt Disappointment more than at Mt Donna Buang.

Pyriproxyfen for the Control of Australian Salt-Marsh Mosquito, Aedes vigilax

2012 ◽  
Vol 28 (1) ◽  
pp. 50-52 ◽  
Author(s):  
Garry Webb ◽  
Peter Miller ◽  
Bryce Peters
Keyword(s):  
Salt Marsh ◽  
Aedes Vigilax

Penetration of remnant edges by noisy miners (Manorina melanocephala) and implications for habitat restoration

2007 ◽  
Vol 34 (4) ◽  
pp. 253 ◽  
Author(s):  
Michael F. Clarke ◽  
Joanne M. Oldland
Keyword(s):  
Penetration Depth ◽  
Habitat Restoration ◽  
Habitat Type ◽  
Bird Species ◽  
Habitat Characteristics ◽  
Noisy Miner ◽  
Eastern Australia ◽  
Negative Effect ◽  
Manorina Melanocephala ◽  
A Site

The noisy miner (Manorina melanocephala) is a large, communally breeding colonial native honeyeater renowned for aggressively excluding virtually all other bird species from areas they occupy. In the woodlands of southern and eastern Australia, numerous studies have identified the domination of remnants by noisy miners as having a profound negative effect on woodland bird communities. Despite this, very little is known about the habitat characteristics that make domination of a site by noisy miners more likely. This study investigated the depth from edges that noisy miners penetrated into large woodland remnants (>48 ha) within Victoria and attempted to identify habitat characteristics that influenced the depth to which they penetrated. Penetration depth differed significantly across four broad habitat types but commonly ranged from 150 m to more than 300 m from the remnant edge. If noisy miners colonise a site, their capacity to penetrate in from a remnant edge has implications for the size that remnants need to be (>36 ha) to contain any core ‘noisy-miner-free’ habitat and the width that habitat corridors need to be to avoid domination by noisy miners (>600 m). Broad differences in habitat type and the abundance of noisy miners at a site were the most powerful predictors of penetration distance. The density of canopy trees on a site was the only other habitat variable contributing to the most parsimonious model of penetration depth. Decreasing density of trees was associated with increasing penetration depth by noisy miners.

scholarly journals Invasive cordgrass (Spartina spp.) in south-eastern Australia induces island formation, salt marsh development, and carbon storage

2017 ◽  
Vol 56 (1) ◽  
pp. 80-91 ◽  
Author(s):  
David M. Kennedy ◽  
Teresa Konlechner ◽  
Elisa Zavadil ◽  
Michela Mariani ◽  
Vanessa Wong ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Carbon Storage ◽  
Island Formation ◽  
South Eastern ◽  
Eastern Australia ◽  
Invasive Cordgrass ◽  
South Eastern Australia

scholarly journals Woodland birds and rural towns: artificial clutch survival in fragmented Box-Ironbark forests

2018 ◽  
Vol 130 (1) ◽  
pp. 7 ◽  
Author(s):  
B. Meney ◽  
S. Cunningham ◽  
M.A. Weston ◽  
D.A. Whisson
Keyword(s):  
Agricultural Landscapes ◽  
Habitat Characteristics ◽  
Woodland Birds ◽  
Landscape Type ◽  
South Eastern ◽  
Avian Predators ◽  
Rural Town ◽  
Eastern Australia ◽  
Landscape Types ◽  
South Eastern Australia

Woodland birds are declining throughout the agricultural landscapes of south-eastern Australia, but the specific mechanisms driving these declines remain unclear. Reproductive failure via clutch depredation could conceivably contribute to these declines. Although site-scale habitat may influence the risk of clutch failure, larger-scale influences, such as whether a landscape contains a rural town or not (‘landscape type’), may also play a role. This study monitored artificial open-cup nests deployed in three pairs of the two landscape types and: 1) indexed clutch survival and predator assemblage; and 2) determined if clutch survival was influenced by landscape type and/or local habitat characteristics. High levels of clutch depredation were observed in both landscape types and for all landscapes, with no evidence to suggest that landscape type or habitat characteristics influenced clutch survival or the time-to-first-predator visit. Predator assemblage also was consistent between landscape types. Generalist avian predators were the most common egg predators. Such egg predators may be ubiquitous throughout the fragmented Box-Ironbark woodlands of south-eastern Australia.

Sign in / Sign up

Export Citation Format

Share Document