Population ecology of the Australian frog Crinia signifera: larvae

1999 ◽  
Vol 26 (1) ◽  
pp. 81 ◽  
Author(s):  
I. Williamson ◽  
C. M. Bull
Keyword(s):  
Population Dynamics ◽  
Population Ecology ◽  
South Australia ◽  
Predation Pressure ◽  
Temporary Pools ◽  
Permanent Pond ◽  
Complete Failure ◽  
One Year ◽  
Predator Community

There are few published studies of the population ecology of the larvae of Australian native anurans. In this study we report on the population dynamics of the larvae of the Australian frog Crinia signifera at a study site near Bridgewater in the Adelaide Hills, South Australia. The predator community was also monitored to provide an indication of the importance of predation in influencing the population dynamics of C. signifera larvae. Pool drying meant larvae failed to metamorphose from temporary pools in all years of the study. In a permanent pond, mortality was high and variable, with an average of 10% survival over the three years of the study. There was a complete failure to recruit to the terrestrial phase in one year. Predation pressure was thought to be the most important source of mortality in the permanent pond, although predator numbers varied considerably between and within years. When combined with information on the population ecology of the embryonic (Williamson and Bull 1994) and terrestrial (Williamson and Bull 1996) stages, the data suggest that the aquatic phase is the key phase in the population dynamics of this species.

Preliminary investigations into the life cycle of Ventruia inaequalis (Cooke) WINT. in South Australia.

1953 ◽  
Vol 4 (4) ◽  
pp. 415 ◽  
Author(s):  
MW Jeffery
Keyword(s):  
Life Cycle ◽  
Primary Infection ◽  
South Australia ◽  
Late Summer ◽  
Relative Importance ◽  
New Information ◽  
One Year

Investigation into the possible sources of primary infection by the fungus Ventruia inaequalis (Cooke) Wint. in spring has been carried out. The results present new information on the life cycle of the pathogen under South Australian conditions. Sources of primary infection, such 'as lesions on one-year-old wood or overwintering superficial conidia on the trees, do not appear important. Bud-scale infection of dormant buds has been shown, and its relative importance is discussed. Ascospores are the most important source of primary infection. Their period of discharge extends to a later date than previously reported for South Australia and is considered in relation to leader shoot and late summer spot infection.

The Initial Response of a Chenopod Shrubland Plant and Invertebrate Community to Two Pulses of Intensive Cattle Grazing.

1999 ◽  
Vol 21 (2) ◽  
pp. 169 ◽  
Author(s):  
JL Read
Keyword(s):  
Water Distribution ◽  
Marked Effect ◽  
Plant Cover ◽  
South Australia ◽  
Initial Response ◽  
Plant Species Richness ◽  
Cattle Grazing ◽  
Invertebrate Community ◽  
Distribution Features ◽  
One Year

The initial effect of two pulses of heavy cattle grazing on chenopod shrubland plants and invertebrates in northern South Australia was assessed in a two year trial. Both plant and invertebrate communities were structured by subhabitats which were defined by edaphic and water-distribution features. The cover of grasses and the dominant shrubs, Atriplex vesicaria and Maireana astrotricha, declined significantly following grazing but only total vegetation cover was significantly lower than controls one year after grazing. Plant species richness was not affected by the grazing pulses. Abundance of ants increased, but the responses of other invertebrates were inconsistent following grazing. Rainfall had a marked effect upon both plant cover and invertebrate abundance. Key words: chenopod shrublands, pulsed cattle grazing, Atriplex vesicaria, invertebrates, bioindicators

Hybrid machine learning process improves operations in South Australian trial

2021 ◽  
Vol 5 (4) ◽  
pp. 1-16
Author(s):  
Kalan Braun ◽  
James Ireland ◽  
Jonathan Klaric
Keyword(s):  
Machine Learning ◽  
Asset Management ◽  
South Australia ◽  
Cloud Data ◽  
Engineering Teams ◽  
Deterministic Modelling ◽  
Full Production ◽  
Machine Learning Applications ◽  
Hybrid Machine ◽  
One Year

TRILITY has developed a production cloud data management solution, KOIOS DatalytiX to provide hybrid machine learning applications and deterministic modelling tools to its operations, asset management, and engineering teams. Two optimiser applications for chemical coagulant prediction and filtration performance were deployed in the Riverland, South Australia at 10 conventional water treatment plants in 2018, to full production in 2019. One year later the impacts on the optimisation behaviour of operations teams, process performance and trihalomethane (THM) reduction outcomes are discussed.

Population Dynamics of White Sharks in Spencer Gulf, South Australia

1996 ◽  
pp. 401-414 ◽  
Author(s):  
WESLEY R. STRONG ◽  
DONALD R. NELSON ◽  
BARRY D. BRUCE ◽  
RICHARD D. MURPHY
Keyword(s):  
Population Dynamics ◽  
South Australia

Population dynamics of three cladocerans of Lago Maggiore related to predation pressure by a planktophagous fish

1975 ◽  
Vol 19 (4) ◽  
pp. 2906-2912 ◽  
Author(s):  
R. de Bernardi ◽  
G. Giussani
Keyword(s):  
Population Dynamics ◽  
Predation Pressure

HEAD INJURY IN SOUTH AUSTRALIA: INCIDENCE OF HOSPITAL ATTENDANCE AND DISABILITY BASED ON A ONE-YEAR SAMPLE

2010 ◽  
Vol 12 (4) ◽  
pp. 428-436 ◽  
Author(s):  
Klee A. Badcock
Keyword(s):  
Head Injury ◽  
South Australia ◽  
One Year

Dormancy in Caladenia: a Bayesian approach to evaluating latency

2009 ◽  
Vol 57 (4) ◽  
pp. 340 ◽  
Author(s):  
Raymond L. Tremblay ◽  
Maria-Eglée Perez ◽  
Matthew Larcombe ◽  
Andrew Brown ◽  
Joe Quarmby ◽  
...  
Keyword(s):  
Bayesian Approach ◽  
Transition Probabilities ◽  
South Australia ◽  
C Elegans ◽  
Emergent Plants ◽  
Terrestrial Orchids ◽  
State Capture ◽  
Population Sizes ◽  
Capture Recapture ◽  
One Year

Dormancy is common in many terrestrial orchids in southern Australia and other temperate environments. The difficulty for conservation and management when considering dormancy is ascertaining whether non-emergent plants are dormant or dead. Here we use a multi-state capture–recapture method, undertaken over several seasons, to determine the likelihood of a plant becoming dormant or dying following its annual emergent period and evaluate the frequency of the length of dormancy. We assess the transition probabilities from time series of varying lengths for the following nine terrestrial orchids in the genus Caladenia: C. amoena, C. argocalla, C. clavigera, C. elegans, C. graniticola, C. macroclavia, C. oenochila, C. rosella and C. valida from Victoria, South Australia and Western Australia. We used a Bayesian approach for estimating survivorship, dormancy and the likelihood of death from capture–recapture data. Considering all species together, the probability of surviving from one year to the next was ~86%, whereas the likelihood of observing an individual above ground in two consecutive years was ~74%. All species showed dormancy of predominantly 1 year, whereas dormancy of three or more years was extremely rare (<2%). The results have practical implications for conservation, in that (1) population sizes of Caladenia species are more easily estimated by being able to distinguish the likelihood of an unseen individual being dormant or dead, (2) population dynamics of individuals can be evaluated by using a 1–3-year dormancy period and (3) survey effort is not wasted on monitoring individuals that have not emerged for many years.

More than just the animals: opportunities and costs of reintroducing threatened black-footed rock-wallabies to remote Indigenous land

2018 ◽  
Vol 24 (4) ◽  
pp. 388 ◽  
Author(s):  
Luke Ireland ◽  
Magdalena Zabek ◽  
Carolina Galindez-Silva ◽  
Sara Weir ◽  
Rebecca West ◽  
...  
Keyword(s):  
Threatened Species ◽  
Large Scale ◽  
Captive Breeding ◽  
Fire Management ◽  
South Australia ◽  
Project Cost ◽  
One Year ◽  
Cross Fostering ◽  
North Western ◽  
Indigenous Land

Conservation activities, including translocations of threatened species, are increasingly important priorities for conserving biodiversity and culture on Indigenous-managed lands, which occupy over 20% of the Australian landmass. In the Anangu Pitjantjatjara Yankunytjatjara (APY) Lands of north-western South Australia, the Warru Recovery Team reintroduced the threatened black-footed rock-wallaby (warru) to Wamitjara in May 2018. We outline the unique planning and logistical issues inherent in securing support and involvement of Traditional Owners and Indigenous rangers for predator, weed and fire management, cross-fostering, captive breeding, monitoring and translocation of the rock-wallabies. Altogether, the project cost AU$3.86 million (actual – AU$1.86 million, in kind – AU$2.00 million) over 10 years of preparation and one year of post-translocation monitoring. This consisted of AU$1.18 million for cross-fostering and captive breeding at Monarto Zoo and a further AU$0.55 million for the construction and maintenance of a fenced exclosure in the APY Lands. It is estimated that AU$0.51 million of the total costs were directly attributed to working remote and Indigenous-owned land, with most of the remaining costs typical of other reintroduction programs. Large-scale reintroduction opportunities on Indigenous-managed land can provide considerable conservation outcomes as well as delivering cultural objectives and supporting employment.

Body growth and its implications in population dynamics of Acanthodactylus erythrurus (Schinz, 1834) in the Eastern Iberian peninsula

2019 ◽  
Vol 40 (3) ◽  
pp. 305-312
Author(s):  
Robby Marcel Drechsler ◽  
Juan Salvador Monrós
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Statistical Significance ◽  
Growth Curves ◽  
High Statistical Significance ◽  
General Data ◽  
One Year ◽  
Best Fit ◽  
Logarithmic Growth

Abstract We calculated growth rate for the spiny-footed lizard (Acanthodactylus erythrurus) inhabiting coastal eastern Spain from long-term mark-recapture data. Growth curves differ between sexes, with males growing faster than females and achieving larger size maximums. In this population each sex reaches maturity at about 300 days of age, approximately 34% faster than males, and 28% faster than females studied in a population further south and west in Iberia. Our logarithmic growth model has an accuracy of 96.8% and high statistical significance ( for males and for females). Although both the exponential curve of “best fit” for growth estimated for males (), and the linear curve of “best fit” estimated for females () in a population from Cádiz (Busack and Jaksic, 1982) are also significant. The overlap between growth curves and the general data cloud of the population showed that at the end of the year the proportion of individuals younger than one year was 80% and the proportion of individuals older than one year was 20%. Our data, in agreement with calculated maximum life spans for males (1.9 years) and females (2.1 years) in Cádiz, suggest a life span of approximately two years for both sexes. Females seem to reproduce only in a unique season in their lives, at this locality, as in Cádiz (Busack and Klosterman, 1987) they likely lay only one clutch, whereas females in Morocco (Bons, 1962) may produce two.

Novel introductions and epidemic dynamics of the sudden oak death pathogen Phytophthora ramorum in Oregon forests

2020 ◽  
Author(s):  
Nicholas C Carleson ◽  
Hazel Daniels ◽  
Paul Reeser ◽  
Alan Kanaskie ◽  
Sarah Navarro ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Population Dynamics ◽  
Microsatellite Loci ◽  
Forest Ecosystems ◽  
Principal Component ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Clonal Lineage ◽  
Epidemic Dynamics ◽  
One Year

Sudden oak death caused by Phytophthora ramorum has been actively managed in Oregon since the early 2000’s. To date, this epidemic has been driven mostly by the NA1 clonal lineage of P. ramorum, but an outbreak of the EU1 lineage has recently emerged. Here we contrast the population dynamics of the NA1 outbreak first reported in 2001 to the outbreak of the EU1 lineage first detected in 2015. We tested if any of the lineages were introduced more than once. Infested regions of the forest were sampled between 2013-2018 (n = 903) and strains were genotyped at 15 microsatellite loci. Most genotypes observed were transient, with 272 of 358 unique genotypes emerging one year and disappearing the next. Diversity of EU1 was very low and isolates were spatially clustered (< 8 km apart), suggesting a single EU1 introduction. Some forest isolates are genetically similar to isolates collected from a local nursery in 2012, suggesting introduction of EU1 from this nursery or simultaneous introduction to both the nursery and latently into the forest. In contrast, the older NA1 populations were more polymorphic and spread over 30 km2. Principal component analysis supported two to four independent NA1 introductions. The NA1 and EU1 epidemics infest the same area but show disparate demographics owing to initial introductions of the lineages spaced 10 years apart. Comparing these epidemics provides novel insights into patterns of emergence of clonal pathogens in forest ecosystems.

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