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1
Clarke, Anthony R., and Penelope F. Measham. "Competition: A Missing Component of Fruit Fly (Diptera: Tephritidae) Risk Assessment and Planning." Insects 13, no. 11 (November 17, 2022): 1065. http://dx.doi.org/10.3390/insects13111065.
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Tephritid fruit flies are internationally significant pests of horticulture. Because they are also highly invasive and of major quarantine concern, significant effort is placed in developing full or partial pest risk assessments (PRAs) for fruit flies, while large investments can be made for their control. Competition between fruit fly species, driven by the need to access and utilise fruit for larval development, has long been recognised by researchers as a fundamental component of fruit fly biology, but is entirely absent from the fruit fly PRA literature and appears not be considered in major initiative planning. First presenting a summary of the research data which documents fruit fly competition, this paper then identifies four major effects of fruit fly competition that could impact a PRA or large-scale initiative: (i) numerical reduction of an existing fruit fly pest species following competitive displacement by an invasive fruit fly; (ii) displacement of a less competitive fruit fly pest species in space, time or host; (iii) ecological resistance to fruit fly invasion in regions already with competitively dominant fruit fly species; and (iv) lesser-pest fruit fly resurgence following control of a competitively superior species. From these four major topics, six more detailed issues are identified, with each of these illustrated by hypothetical, but realistic biosecurity scenarios from Australia/New Zealand and Europe. The scenarios identify that the effects of fruit fly competition might both positively or negatively affect the predicted impacts of an invasive fruit fly or targeted fruit fly control initiative. Competition as a modifier of fruit fly risk needs to be recognised by policy makers and incorporated into fruit fly PRAs and major investment initiatives.
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Nield, Andrew P., Philip G. Ladd, and Colin J. Yates. "Reproductive biology, post-fire succession dynamics and population viability analysis of the critically endangered Western Australian shrub Calytrix breviseta subsp. breviseta (Myrtaceae)." Australian Journal of Botany 57, no. 6 (2009): 451. http://dx.doi.org/10.1071/bt09043.
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Calytrix breviseta Lindl. subsp. breviseta is a critically endangered, obligate-seeder shrub within fire-prone kwongan of south-west Western Australia. Little is known about the species’ reproductive biology and how threatening processes, particularly altered fire regimes and exotic species invasion, will impact the long-term viability of the species. This study aims to elucidate the species’ reproductive biology and patterns of seedling recruitment during succession after fire. The effects of changes to the fire return interval and exotic species invasion on the long-term viability of the species is also described. The species exhibits abundant recruitment following fire and the application of a smoke treatment significantly improves germination, similar to many other Western Australian shrubs. However, significant inter-fire recruitment was observed up to 10 years following fire, leading to the presence of multi-aged subpopulations, although seedling recruitment was negligible >20 years after fire. The juvenile period is short at 3–4 years to first flowering. Population viability analysis (PVA) predicted that the optimal fire return interval to maintain C. breviseta subsp. breviseta was dependent on the carrying capacity (K) of the community and the number of individuals present. Carrying capacity will be related to site quality and competition from invasive species. PVA showed that if K remains high, then the optimal fire return interval is ~15–20 years, but under lower carrying capacity, (i.e. weed competition) fires decrease the likelihood of population survival.
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Karubian, Jordan. "The Social Organization and Mating System of the Striated Grasswren." Condor 103, no. 2 (May 1, 2001): 412–17. http://dx.doi.org/10.1093/condor/103.2.412.
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Abstract This paper summarizes the breeding biology, social organization, and mating system of the Striated Grasswren (Amytornis striatus), a member of one of the least-known genera of Australian passerines, the grasswrens. I studied 18 color-banded groups and 14 nests in South Australia for one breeding season in 1996. Mean territory size was 3.0 ha, and territories consisted of sandy dunes dominated by spinifex (Triodea irritans). This apparent dependency on mature spinifex, coupled with poor dispersal ability, suggests that the Striated Grasswren is particularly susceptible to habitat destruction. Most groups consisted of socially monogamous pairs, mean group size was 2.1 adults, and the adult sex ratio was 0.95 (males:females). The average clutch size was 2.2 ± 0.4 eggs and an average of 1.1 ± 1.1 young fledged per nesting effort. A male and a female provided similar amounts of parental care at a single nest. Cloacal protuberance size and amount of sperm collected did not suggest intense sperm competition among males.
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Fromant, Aymeric, Nicole Schumann, Peter Dann, Yves Cherel, and John P. Y. Arnould. "Trophic niches of a seabird assemblage in Bass Strait, south-eastern Australia." PeerJ 8 (March 11, 2020): e8700. http://dx.doi.org/10.7717/peerj.8700.
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The foraging niches of seabirds are driven by a variety of factors, including competition for prey that promotes divergence in trophic niches. Bass Strait, south-eastern Australia, is a key region for seabirds, with little penguins Eudyptula minor, short-tailed shearwaters Ardenna tenuirostris, fairy prions Pachyptila turtur and common diving-petrels Pelecanoides urinatrix being particularly abundant in the region. The trophic niches of these species were investigated using isotopic values in whole blood and by identifying prey remains in stomach contents. The four species occupied different isotopic niches that varied among years, seasons and regions. Little penguins consumed mainly fish whereas the three procellariforms primarily consumed coastal krill Nyctiphanes australis. The dietary similarities between the procellariforms suggest that food resources are segregated in other ways, with interspecific differences in isotope niches possibly reflecting differential consumption of key prey, divergent foraging locations and depth, and differences in breeding phenology. Because oceanographic changes predicted to occur due to climate change may result in reduced coastal krill availability, adversely affecting these seabird predators, further information on foraging zones and feeding behaviour of small procellariform species is needed to elucidate more fully the segregation of foraging niches, the capacity of seabirds to adapt to climate change and the potential for interspecific competition in the region.
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Strzepek, Kenneth, and Brent Boehlert. "Competition for water for the food system." Philosophical Transactions of the Royal Society B: Biological Sciences 365, no. 1554 (September 27, 2010): 2927–40. http://dx.doi.org/10.1098/rstb.2010.0152.
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Although the global agricultural system will need to provide more food for a growing and wealthier population in decades to come, increasing demands for water and potential impacts of climate change pose threats to food systems. We review the primary threats to agricultural water availability, and model the potential effects of increases in municipal and industrial (M&I) water demands, environmental flow requirements (EFRs) and changing water supplies given climate change. Our models show that, together, these factors cause an 18 per cent reduction in the availability of worldwide water for agriculture by 2050. Meeting EFRs, which can necessitate more than 50 per cent of the mean annual run-off in a basin depending on its hydrograph, presents the single biggest threat to agricultural water availability. Next are increases in M&I demands, which are projected to increase upwards of 200 per cent by 2050 in developing countries with rapidly increasing populations and incomes. Climate change will affect the spatial and temporal distribution of run-off, and thus affect availability from the supply side. The combined effect of these factors can be dramatic in particular hotspots, which include northern Africa, India, China, parts of Europe, the western US and eastern Australia, among others.
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Mitchell, M. L., J. M. Virgona, J. L. Jacobs, and D. R. Kemp. "Population biology of Microlaena stipoides in a south-eastern Australian pasture." Crop and Pasture Science 65, no. 8 (2014): 767. http://dx.doi.org/10.1071/cp13404.
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Microlaena (Microlaena stipoides var. stipoides (Labill.) R.Br.) is a C3 perennial grass that is native to areas of south-eastern Australia. In this region, perennial grasses are important for the grazing industries because of their extended growing season and persistence over several years. This series of experiments focused on the population biology of Microlaena by studying the phenology (when seed was set), seed rain (how much seed was produced and where it fell), seed germination, germinable seedbank, seed predation and seedling recruitment in a pasture. Experiments were conducted at Chiltern, in north-eastern Victoria, on an existing native grass pasture dominated by Microlaena. Seed yields were substantial (mean 800 seeds m–2), with seed rain occurring over December–May. Microlaena has two distinct periods of high seed rain, in early summer and in early autumn. Seed predation is high. Within a 24-h period during peak seed production, up to 30% of Microlaena seed was removed from a pasture, primarily by ants. Microlaena seedlings recruited throughout an open paddock; however, seedling density was low (5 seedlings m–2). Microlaena represented only low numbers in the seedbank (0.01–0.05% of total); hence, any seedlings of Microlaena that germinate from the seedbank would face immense competition from other species. Management strategies for Microlaena-dominant pastures need to focus on the maintenance of existing plants.
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Bebawi, Faiz F., Shane D. Campbell, and Robert J. Mayer. "Can competition with pasture be used to manipulate bellyache bush (Jatropha gossypiifolia L.) population biology?" Rangeland Journal 35, no. 4 (2013): 393. http://dx.doi.org/10.1071/rj13011.
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Bellyache bush (Jatropha gossypiifolia L.) is an invasive weed that poses economic and environmental problems in northern Australia. Competition between pasture and bellyache bush was examined in North Queensland using combinations of five pasture treatments (uncut (control); cut as low, medium, and high pasture; and no pasture) and four bellyache bush densities (0, 2, 6 and 12 plants m−2) in a buffel grass (Cenchrus ciliaris L.) dominated pasture. The pasture treatments were applied approximately once per year but no treatments were applied directly to the bellyache bush plants. Measurements of bellyache bush flowering, seed formation, and mortality were undertaken over a 9-year period, along with monitoring the pasture basal cover and plant species diversity. Maximum flowering rates of bellyache bush occurred after 9 years (97%) in plots containing no pasture, with the lowest rates of 9% in uncut control plots. Earliest flowering (322 days after planting) and seed formation (411 days) also occurred in plots with no pasture compared with all other pasture treatments (range 1314–1393 days for seed formation to occur). No seeds were produced in uncut plots. At the end of 9 years, mortality rates of bellyache bush plants initially planted averaged ≥73% for treatments with some pasture compared with 55% under the no-pasture treatment. The percentage of herbaceous plant basal cover in uncut plots was increased 5-fold after 9 years, much greater than the average 2% increase recorded across the low, medium, and high pasture treatments. The number of herbaceous species in uncut plots remained largely unchanged, whereas there was an average reduction of 46% in the cut pasture treatments. Buffel grass remained the species with the greatest basal cover across all cut pasture treatments, followed by sabi grass (Urochloa mosambicensis (Hack.) Dandy) and then red Natal grass (Melinis repens (Willd.) Ziska). These results suggest that grazing strategies that maintain a healthy and competitive pasture layer may contribute to reducing the rate of spread of bellyache bush and complement traditional control techniques such as the use of herbicides.
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Ridsdill-Smith, T. J., A. A. Hoffmann, G. P. Mangano, J. M. Gower, C. C. Pavri, and P. A. Umina. "Strategies for control of the redlegged earth mite in Australia." Australian Journal of Experimental Agriculture 48, no. 12 (2008): 1506. http://dx.doi.org/10.1071/ea08020.
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The redlegged earth mite, Halotydeus destructor, continues to be an intractable pest causing damage to most crop and pasture species in southern Australia. H. destructor feed on all stages of plants, but particularly damage seedlings in autumn. Research has aimed to develop new controls based on a better understanding of the biology and ecology of this pest. Chemicals remain the key tool to control H. destructor, despite the recent appearance of resistance to synthetic pyrethroids. A control package, Timerite, has been developed by which a single well-timed spray in spring can prevent H. destructor from developing diapause eggs. Field trials show this strategy provides effective control of H. destructor the following autumn, and protects plant seedlings, although mite populations build up again during winter. Non-chemical control strategies include grazing, the use of tolerant plants such as cereals, resistant legume cultivars and avoiding rotations where favourable host plants are available in the year before growing susceptible crops such as canola. Natural enemies can assist in mite control, and their numbers can be enhanced by methods including increasing landscape features like shelterbelts. Interspecific competition can occur between H. destructor and other pest mites, but the extent to which these interactions influence the structure of pest communities under different management regimes remains to be investigated.
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Arena, Derrick A., Michael Archer, Henk Godthelp, Suzanne J. Hand, and Scott Hocknull. "Hammer-toothed ‘marsupial skinks' from the Australian Cenozoic." Proceedings of the Royal Society B: Biological Sciences 278, no. 1724 (April 20, 2011): 3529–33. http://dx.doi.org/10.1098/rspb.2011.0486.
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Extinct species of Malleodectes gen. nov. from Middle to Late Miocene deposits of the Riversleigh World Heritage Area, northwestern Queensland, Australia are enigmatic, highly specialized, probably snail-eating marsupials. Dentally, they closely resemble a bizarre group of living heterodont, wet forest scincid lizards from Australia ( Cyclodomorphus ) that may well have outcompeted them as snail-eaters when the closed forests of central Australia began to decline. Although there are scincids known from the same Miocene deposits at Riversleigh, these are relatively plesiomorphic, generalized feeders. This appears to be the most striking example known of dental convergence and possible competition between a mammal and a lizard, which in the long run worked out better for the lizards.
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Smith, Adam, Al Songcuan, Jonathan Mitchell, Max Haste, Zachary Schmidt, Glenn Sands, and Marcus Lincoln Smith. "Quantifying Catch Rates, Shark Abundance and Depredation Rate at a Spearfishing Competition on the Great Barrier Reef, Australia." Biology 11, no. 10 (October 18, 2022): 1524. http://dx.doi.org/10.3390/biology11101524.
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We developed and applied a method to quantify spearfisher effort and catch, shark interactions and shark depredation in a boat-based recreational spearfishing competition in the Great Barrier Reef Marine Park in Queensland. Survey questions were designed to collect targeted quantitative data whilst minimising the survey burden of spearfishers. We provide the first known scientific study of shark depredation during a recreational spearfishing competition and the first scientific study of shark depredation in the Great Barrier Reef region. During the two-day spearfishing competition, nine vessels with a total of 33 spearfishers reported a catch of 144 fish for 115 h of effort (1.25 fish per hour). A subset of the catch comprised nine eligible species under competition rules, of which 47 pelagic fish were weighed. The largest fish captured was a 34.4 kg Sailfish (Istiophorus platypterus). The most common species captured and weighed was Spanish Mackerel (Scomberomorus commerson). The total weight of eligible fish was 332 kg and the average weight of each fish was 7.1 kg. During the two-day event, spearfishers functioned as citizen scientists and counted 358 sharks (115 h effort), averaging 3.11 sharks per hour. Grey Reef Sharks (Carcharhinus amblyrhynchos) comprised 64% of sightings. Nine speared fish were fully depredated by sharks as spearfishers attempted to retrieve their catch, which equates to a depredation rate of 5.9%. The depredated fish included four pelagic fish and five reef fish. The shark species responsible were Grey Reef Shark (C. amblyrhynchos) (66%), Bull Shark (Carcharhinus leucas) (11%), Whitetip Reef Shark (Triaenodon obesus) (11%) and Great Hammerhead (Sphyrna mokarran) (11%). There were spatial differences in fish catch, shark sightings and rates of depredation. We developed a report card that compared average catch of fish, sightings of sharks per hour and depredation rate by survey area, which assists recreational fishers and marine park managers to assess spatio-temporal changes. The participating spearfishers can be regarded as experienced (average 18 days a year for average 13.4 years). Sixty percent of interviewees perceived that shark numbers have increased in the past 10 years, 33% indicated no change and 7% indicated shark numbers had decreased. Total fuel use of all vessels was 2819 L and was equivalent to 6.48 tons of greenhouse gas emissions for the competition.
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Willers, Nicole, Peter Mawson, Keith Morris, and Roberta Bencini. "Biology and population dynamics of the black-flanked rock-wallaby (Petrogale lateralis lateralis) in the central wheatbelt of Western Australia." Australian Mammalogy 33, no. 2 (2011): 117. http://dx.doi.org/10.1071/am10036.
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Through a mark–recapture study, we explored aspects of the biology and population dynamics in the largest known population of the black-flanked rock-wallaby (Petrogale lateralis lateralis) at Mt Caroline Nature Reserve, in the Western Australian wheatbelt in 2007–10. The body condition index of males and females varied significantly over time but fluctuated similarly for both sexes. Males and females followed a pattern of best condition in early summer, declining through autumn and reaching their poorest condition in early spring. Body condition was closely related to rainfall in the period ~3–6 months before trapping sessions. Births occurred throughout the year with two reproductive peaks, in autumn and late winter/spring. Reproductive rates averaged over 90% annually, except in 2007 when they averaged 76%. Significantly fewer females bred during 2007, and those females were in poorer body condition. Females with a higher body condition index were more likely to reproduce (P = 0.003) but body condition did not influence the sex of offspring. The sex ratio of offspring did not differ significantly from parity and did not support either the Trivers–Willard or local resource competition hypotheses. This information should help to predict population trends and develop appropriate conservation strategies for this threatened species.
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Krebs, Elizabeth A. "Breeding biology of crimson rosellas (Platycercus elegans) on Black Mountain, Australian Capital Territory." Australian Journal of Zoology 46, no. 2 (1998): 119. http://dx.doi.org/10.1071/zo97040.
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The breeding behaviour of crimson rosellas (Platycercus elegans) in Canberra, Australia, was studied between 1993 and 1996. Female rosellas initiated breeding in late September or early October, laying a mean of 5.3 ± 0.1 (s.e.) eggs at 1–4-day intervals. Of all eggs laid, 50% fledged successfully. Rosellas had the highest breeding success in the wettest year (1995), when they bred earlier, laid larger clutches and fledged more young. Unexpectedly, breeding success was not lowest in the driest year (1994), although fewer birds attempted breeding and hatching success was low. In this study, poor environmental conditions for breeding were counterbalanced by decreased levels of conspecific interference through egg destruction. Overall, 55.8% of all clutches initiated were destroyed during laying, and more than half of this was attributed to rosellas. The reasons for egg destruction by rosellas were not clear. Boxes where clutches were destroyed were not quickly reoccupied and egg destruction was not highest when competition for nesting hollows was most intense. Clutch size and egg-laying intervals decreased over the breeding season, but the length of incubation did not. Large clutches did not produce more fledglings, because more eggs failed to hatch, especially early in the season. Eggs in a clutch hatched over a period of 0.5–7 days. Total hatching asynchrony increased over the breeding season and was not strongly correlated with clutch or brood size. This suggests that female rosellas initiated incubation at different times during laying. Clutches with longer hatching intervals took longer to incubate. If females in poor condition are inefficient incubators, female condition may affect the degree of hatching asynchrony.
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Hardy, Christopher M., Mark Adams, Dean R. Jerry, Leon N. Court, Matthew J. Morgan, and Diana M. Hartley. "DNA barcoding to support conservation: species identification, genetic structure and biogeography of fishes in the Murray - Darling River Basin, Australia." Marine and Freshwater Research 62, no. 8 (2011): 887. http://dx.doi.org/10.1071/mf11027.
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Freshwater fish stocks worldwide are under increasing threat of overfishing, disease, pollution and competition from introduced species. In the Murray—Darling Basin (MDB), the largest river system of Australia, more than half the native species are listed as rare or endangered. Active management is required to counteract reduction in population sizes, prevent local extinctions and to maintain genetic diversity. We describe the first comprehensive set of DNA barcodes able to discriminate between all 58 native and introduced species of freshwater fish recorded in the MDB. These barcodes also distinguish populations from those in adjacent basins, with estimated separation times as short as 0.1 million years ago. We demonstrate the feasibility of using DNA fingerprinting of ribosomal RNA (12S and 18S rRNA) genes and mitochondrial DNA control region (mtDNA CR) sequences to identify species from eggs, larvae, tissues and predator gut contents as well as differentiate populations, morphologically cryptic species and hybrids. The DNA barcode resource will enhance capacity in many areas of fish conservation biology that can benefit from improved knowledge of genetic provenance. These include captive breeding and restocking programs, life history studies and ecological research into the interactions between populations of native and exotic species.
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Chadha, Aakansha, and Singarayer Florentine. "Biology, Ecology, Distribution and Control of the Invasive Weed, Lactuca serriola L. (Wild Lettuce): A Global Review." Plants 10, no. 10 (October 11, 2021): 2157. http://dx.doi.org/10.3390/plants10102157.
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Lactuca serriola L. (wild lettuce) is a highly invasive C3 weed in many countries, including Australia, Canada, and the USA. This weed is a severe threat to agricultural systems, especially in crops grown with reduced or no-tillage approaches, which commonly include wheat, cereals and pulses. Owing to the vertical orientation of its leaves in the north-south plane and its root architecture, L. serriola can maintain high water use efficiency under drought conditions, giving it the ability to expand its range under a drying climate. Each plant can produce up to 100,000 seeds which have no primary dormancy and form a short-term seedbank lasting up to three years. Most seedlings emerge in autumn and overwinter as a rosette, with a small flush of emergence in spring depicting staggered germination. Research into control methods for this weed has been performed, and these methods include chemical herbicides applied alone and in combination, the establishment of plant competition, tillage, mowing and bioherbicide. Herbicides can provide effective control when applied in the seedling or rosette stage; however, spring germination is difficult to control, as it skips the rosette stage. Some biotypes are now resistant to ALS inhibitor and synthetic auxins, causing concern regarding using herbicides. A dedicated integrated management plan for 3–4 years is recommended for the control of this troublesome species. This review will explore the biology, ecology, distribution, current control techniques and previous research on this weed, allowing us to make recommendations for its future research and management.
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Rowe, Melissah, and Stephen Pruett-Jones. "Reproductive biology and sperm competition in Australian fairy-wrens." Avian and Poultry Biology Reviews 17, no. 1 (February 2006): 21–37. http://dx.doi.org/10.3184/147020606783437949.
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Bajwa, Ali Ahsan, Sajid Latif, Catherine Borger, Nadeem Iqbal, Md Asaduzzaman, Hanwen Wu, and Michael Walsh. "The Remarkable Journey of a Weed: Biology and Management of Annual Ryegrass (Lolium rigidum) in Conservation Cropping Systems of Australia." Plants 10, no. 8 (July 22, 2021): 1505. http://dx.doi.org/10.3390/plants10081505.
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Annual ryegrass (Lolium rigidum Gaud.), traditionally utilised as a pasture species, has become the most problematic and difficult-to-control weed across grain production regions in Australia. Annual ryegrass has been favoured by the adoption of conservation tillage systems due to its genetic diversity, prolific seed production, widespread dispersal, flexible germination requirements and competitive growth habit. The widespread evolution of herbicide resistance in annual ryegrass has made its management within these systems extremely difficult. The negative impacts of this weed on grain production systems result in annual revenue losses exceeding $93 million (AUD) for Australian grain growers. No single method of management provides effective and enduring control hence the need of integrated weed management programs is widely accepted and practiced in Australian cropping. Although annual ryegrass is an extensively researched weed, a comprehensive review of the biology and management of this weed in conservation cropping systems has not been conducted. This review presents an up-to-date account of knowledge on the biology, ecology and management of annual ryegrass in an Australian context. This comprehensive account provides pragmatic information for further research and suitable management of annual ryegrass.
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John, Evan, Silke Jacques, Huyen T. T. Phan, Lifang Liu, Danilo Pereira, Daniel Croll, Karam B. Singh, Richard P. Oliver, and Kar-Chun Tan. "Variability in an effector gene promoter of a necrotrophic fungal pathogen dictates epistasis and effector-triggered susceptibility in wheat." PLOS Pathogens 18, no. 1 (January 6, 2022): e1010149. http://dx.doi.org/10.1371/journal.ppat.1010149.
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The fungus Parastagonospora nodorum uses proteinaceous necrotrophic effectors (NEs) to induce tissue necrosis on wheat leaves during infection, leading to the symptoms of septoria nodorum blotch (SNB). The NEs Tox1 and Tox3 induce necrosis on wheat possessing the dominant susceptibility genes Snn1 and Snn3B1/Snn3D1, respectively. We previously observed that Tox1 is epistatic to the expression of Tox3 and a quantitative trait locus (QTL) on chromosome 2A that contributes to SNB resistance/susceptibility. The expression of Tox1 is significantly higher in the Australian strain SN15 compared to the American strain SN4. Inspection of the Tox1 promoter region revealed a 401 bp promoter genetic element in SN4 positioned 267 bp upstream of the start codon that is absent in SN15, called PE401. Analysis of the world-wide P. nodorum population revealed that a high proportion of Northern Hemisphere isolates possess PE401 whereas the opposite was observed in representative P. nodorum isolates from Australia and South Africa. The presence of PE401 removed the epistatic effect of Tox1 on the contribution of the SNB 2A QTL but not Tox3. PE401 was introduced into the Tox1 promoter regulatory region in SN15 to test for direct regulatory roles. Tox1 expression was markedly reduced in the presence of PE401. This suggests a repressor molecule(s) binds PE401 and inhibits Tox1 transcription. Infection assays also demonstrated that P. nodorum which lacks PE401 is more pathogenic on Snn1 wheat varieties than P. nodorum carrying PE401. An infection competition assay between P. nodorum isogenic strains with and without PE401 indicated that the higher Tox1-expressing strain rescued the reduced virulence of the lower Tox1-expressing strain on Snn1 wheat. Our study demonstrated that Tox1 exhibits both ‘selfish’ and ‘altruistic’ characteristics. This offers an insight into a complex NE-NE interaction that is occurring within the P. nodorum population. The importance of PE401 in breeding for SNB resistance in wheat is discussed.
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Connor, Richard C. "Dolphin social intelligence: complex alliance relationships in bottlenose dolphins and a consideration of selective environments for extreme brain size evolution in mammals." Philosophical Transactions of the Royal Society B: Biological Sciences 362, no. 1480 (February 12, 2007): 587–602. http://dx.doi.org/10.1098/rstb.2006.1997.
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Bottlenose dolphins in Shark Bay, Australia, live in a large, unbounded society with a fission–fusion grouping pattern. Potential cognitive demands include the need to develop social strategies involving the recognition of a large number of individuals and their relationships with others. Patterns of alliance affiliation among males may be more complex than are currently known for any non-human, with individuals participating in 2–3 levels of shifting alliances. Males mediate alliance relationships with gentle contact behaviours such as petting, but synchrony also plays an important role in affiliative interactions. In general, selection for social intelligence in the context of shifting alliances will depend on the extent to which there are strategic options and risk. Extreme brain size evolution may have occurred more than once in the toothed whales, reaching peaks in the dolphin family and the sperm whale. All three ‘peaks’ of large brain size evolution in mammals (odontocetes, humans and elephants) shared a common selective environment: extreme mutual dependence based on external threats from predators or conspecific groups. In this context, social competition, and consequently selection for greater cognitive abilities and large brain size, was intense.
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Fairclough, DV. "Partitioning of marine transition zone reefs among temperate, sub-tropical and tropical fishes is related more to depth and habitat than temperature." Marine Ecology Progress Series 672 (August 19, 2021): 175–92. http://dx.doi.org/10.3354/meps13778.
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Changes in fish communities as oceans warm and cool and competition for space between established and novel species can be evaluated in biogeographic transition zones such as the west coast of Australia. At ~30° S in this region, a cool anomaly occurred in the 2000s, between marine heatwaves. Over 2 yr of that anomaly, surveyed reef fishes were 57% temperate, 18% sub-tropical and 25% tropical. The most numerous fishes included a wrasse, herring, bullseye, drummer and damselfish. Based on similarities in the composition of fishes, 7 significant clusters of reefs were identified along a gradation from deep, exposed reefs to shallow, protected lagoonal reefs. Endemic sub-tropical and temperate wrasses and damselfishes typified all reefs. Some of these were ubiquitous over exposed and lagoonal reefs and others prevalent in only one reef type, demonstrating habitat preferences and partitioning among closely related species. This was reflected in the differing order of importance of fishes that typified different reefs. Linear modelling indicated that abiotic (depth, distance from shore) and biotic factors (e.g. algae) explained most of the variation in the fish communities among reefs. Additional variation, particularly within lagoonal reefs, was related to relief, turf and corals, rather than water temperature. Occurrence and reproductive activity of a group of tropical/sub-tropical wrasses and damselfish in some lagoonal reefs with abundant tropical habitats (e.g. corals) suggested that they supported novel communities during cool anomalies. Better predictions of future change and interactions between existing and novel species with environmental cycles requires knowledge of species-specific habitat relationships and biology.
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Oram, Rex, and Greg Lodge. "Trends in temperate Australian grass breeding and selection." Australian Journal of Agricultural Research 54, no. 3 (2003): 211. http://dx.doi.org/10.1071/ar02137.
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Current trends in grass cultivar development are reviewed, with respect to the range of species involved, and the objectives and methodology within each species. Extrapolations and predictions are made about future directions and methodologies. It is assumed that selection will necessarily cater for the following environmental changes: (1) higher year-round temperatures, higher variability of rainfall incidence, and lower total winter and spring rainfall along the south of the continent; (2) higher nutrient and lime inputs as land utilisation intensifies; and (3) the grazing management requirements of the important pasture components will be increasingly defined and met in practice.The 'big four' species, perennial ryegrass, phalaris, cocksfoot and tall fescue, will continue to be the most widely sown species in temperate regions for many decades, with the latter 3 increasing most in area and genetic differentiation. However, species diversification will continue, especially with native grasses, legumes, and shrubs from fertile regions of Australia and exotics from little-explored parts of the world, such as South Africa, western North and South America, coastal Caucasus, and Iraq–Iran. By contrast, the recent high rate of species diversification in the tropics and subtropics will probably give way to a much lower rate of cultivar development by refinement and diversification within the established species. Domestication of native grasses will continue for amenity, recreational, land protection, and grazing purposes. As seed harvesting technologies and ecological knowledge improve, natural stands will become increasingly important as local sources of seed. It is suggested that many native grasses have been greatly changed by natural selection so as to withstand strong competition from introduced species under conditions of higher soil fertility and grazing pressure. Conversely, some introduced species are being selected consciously and naturally to persist in regions with irregular rainfall and less fertile soils. Therefore, the distinction between native and introduced grasses may be disappearing, and many populations of native species could now be as foreign to the habitats of pre-European settlement as are populations of introduced species that have been evolving here for 50–200 years. Methods used for genetic improvement will continue to be selection among both overseas accessions and the many native and introduced populations that have responded to natural selection in Australia. As well, there will be deliberate recurrent crossing and selection programs in both native and introduced species for specific purposes and environments. Increasingly, molecular biology methods will complement traditional ones, at first by the provision of DNA markers to assist the selection of complex traits, and for proving distinctness to obtain Plant Breeders' Rights for new cultivars. Later, genetic engineering will be used to manipulate nutritive value, resistance to fungal and viral diseases, and breeding systems, especially cytoplasmic male sterility and apomixis, to utilise heterosis in hybrid cultivars of grasses, particularly for dairying and intensive meat production.Areas where the practice and management of grass breeding and selection programs could be improved are highlighted throughout the review, and reiterated in a concluding statement. Most problems appear to stem from inadequate training in population ecology, population genetics, evolution, and quantitative inheritance.
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Van Dyke, James U., Michael B. Thompson, Christopher P. Burridge, Meghan A. Castelli, Simon Clulow, Duminda S. B. Dissanayake, Caroline M. Dong, et al. "Australian lizards are outstanding models for reproductive biology research." Australian Journal of Zoology 68, no. 4 (2020): 168. http://dx.doi.org/10.1071/zo21017.
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Australian lizards are a diverse group distributed across the continent and inhabiting a wide range of environments. Together, they exhibit a remarkable diversity of reproductive morphologies, physiologies, and behaviours that is broadly representative of vertebrates in general. Many reproductive traits exhibited by Australian lizards have evolved independently in multiple lizard lineages, including sociality, complex signalling and mating systems, viviparity, and temperature-dependent sex determination. Australian lizards are thus outstanding model organisms for testing hypotheses about how reproductive traits function and evolve, and they provide an important basis of comparison with other animals that exhibit similar traits. We review how research on Australian lizard reproduction has contributed to answering broader evolutionary and ecological questions that apply to animals in general. We focus on reproductive traits, processes, and strategies that are important areas of current research, including behaviours and signalling involved in courtship; mechanisms involved in mating, egg production, and sperm competition; nesting and gestation; sex determination; and finally, birth in viviparous species. We use our review to identify important questions that emerge from an understanding of this body of research when considered holistically. Finally, we identify additional research questions within each topic that Australian lizards are well suited for reproductive biologists to address.
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Henskens, F. L. F. "The biology and management of Axonopus affinis (Chase) in Australian pastures." Australian Journal of Agricultural Research 48, no. 8 (1997): 1219. http://dx.doi.org/10.1071/a97023.
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Carpetgrass (Axonopus affinis Chase) was described in terms of its botany, origin, distribution, seasonal growth, habitat, and dispersal. Factors that determine its agronomic importance were examined. Emphasis was given to management and ecological factors which influence competition between carpetgrass and sown pasture species. It is concluded that the management strategies that have been developed and successfully adopted in Queensland and New South Wales need to be tested for use in irrigated pastures in northern Victoria
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Browne, Peter R., Carl T. Woods, Alice J. Sweeting, and Sam Robertson. "Applications of a working framework for the measurement of representative learning design in Australian football." PLOS ONE 15, no. 11 (November 30, 2020): e0242336. http://dx.doi.org/10.1371/journal.pone.0242336.
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Representative learning design proposes that a training task should represent informational constraints present within a competitive environment. To assess the level of representativeness of a training task, the frequency and interaction of constraints should be measured. This study compared constraint interactions and their frequencies in training (match simulations and small sided games) with competition environments in elite Australian football. The extent to which constraints influenced kick and handball effectiveness between competition matches, match simulations and small sided games was determined. The constraints of pressure and time in possession were assessed, alongside disposal effectiveness, through an association rule algorithm. These rules were then expanded to determine whether a disposal was influenced by the preceding disposal. Disposal type differed between training and competition environments, with match simulations yielding greater representativeness compared to small sided games. The subsequent disposal was generally more effective in small sided games compared to the match simulations and competition matches. These findings offer insight into the measurement of representative learning designs through the non-linear modelling of constraint interactions. The analytical techniques utilised may assist other practitioners with the design and monitoring of training tasks intended to facilitate skill transfer from preparation to competition.
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Egidi, Eleonora, and Ashley E. Franks. "Incorporating fungal community ecology into invasion biology: challenges and opportunities." Microbiology Australia 39, no. 1 (2018): 56. http://dx.doi.org/10.1071/ma18015.
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Recently, the role of the plant-associated mycobiome (i.e. the fungal community) in influencing the competitive success of invasive plant species has received increasing attention. Fungi act as primary drivers of the plant invasion process due to their ability to form both beneficial and detrimental relationships with terrestrial plant species. Here we review the role of the plant mycobiome in promoting or inhibiting plant species invasion into foreign ecosystems. Moreover, the potential to exploit these relationships for invasive plant control and restoration of native communities is discussed. Incorporating fungal community ecology into invasion and restoration biology will aid in the management and control of invasive plant species in Australia.
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Gleeson, Deborah, Belinda Townsend, Ruth Lopert, Joel Lexchin, and Hazel Moir. "Financial costs associated with monopolies on biologic medicines in Australia." Australian Health Review 43, no. 1 (2019): 36. http://dx.doi.org/10.1071/ah17031.
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Objectives The aim of the study was to estimate the potential savings to the Pharmaceutical Benefits Scheme (PBS) and the Repatriation Pharmaceutical Benefits Scheme (RPBS) in 2015–16 if biosimilar versions of selected biologic medicines (biologics) had been available and listed on the PBS. Methods The research involved retrospective analysis of Australian Medicare expenditure data and PBS price data from 2015–16 for biologics, for which biosimilar competition may be available in future, listed on the PBS. Results Australian Government expenditure on biologics on the PBS and RPBS was estimated at A$2.29 billion dollars in 2015–16. If biosimilar versions of these medicines had been listed on the PBS in 2015–16, at least A$367million dollars would have been saved in PBS and RPBS subsidies. Modelling based on price decreases following listing of biosimilars on the PBS suggests that annual PBS outlays on biologics could be reduced by as much as 24% through the timely introduction of biosimilars. Conclusions Biologic medicines represent a large proportion of government expenditure on pharmaceuticals. Reducing the length of monopoly protections on these medicines could generate savings of hundreds of millions of dollars per year. What is known about the topic? Biologics take up an increasing share of pharmaceutical expenditure, but no previous published studies have examined Australian Government expenditure on biologics or the potential savings from reducing the duration of monopoly protection. What does this paper add? This paper provides new evidence about Australian Government expenditure on biologics and potential savings for selected medicines that are still subject to monopoly protection and thus are not yet subject to biosimilar competition. In 2015–16 Australian Government expenditure on biologics through the PBS and RPBS was estimated at A$2.29 billion dollars. If biosimilar versions of these medicines had been listed on the PBS at that time, at least A$367million dollars would have been saved. What are the implications for practitioners? Reducing the duration of monopoly protection on biologic medicines could save hundreds of millions of dollars annually that could be redirected to other areas of the healthcare system.
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Moschilla, Joe A., Joseph L. Tomkins, and Leigh W. Simmons. "Males adjust their manipulation of female remating in response to sperm competition risk." Proceedings of the Royal Society B: Biological Sciences 287, no. 1934 (September 2, 2020): 20201238. http://dx.doi.org/10.1098/rspb.2020.1238.
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To reduce the potential for sperm competition, male insects are thought to inhibit the post-mating reproductive behaviour of females through receptivity-inhibiting compounds transferred in the ejaculate. Selection is expected to favour phenotypic plasticity in male post-copulatory expenditure, with males investing strategically in response to their perceived risk of sperm competition. However, the impact that socially cued strategic allocation might have on female post-mating behaviour has rarely been assessed. Here, we varied male perception of sperm competition risk, both prior to and during mating, to determine if a male's competitive environment impacts the extent to which he manipulates female remating behaviour. We found that female Australian field crickets ( Teleogryllus oceanicus ) mated to males that were reared under sperm competition risk emerged from a shelter in search of male song sooner than did females mated to males reared without risk, but only when mating occurred in a risk-free environment. We also found that females reared in a silent environment where potential mates were scarce emerged from the shelter sooner than females exposed to male calls during development. Collectively, our findings suggest complex interacting effects of male and female sociosexual environments on female post-mating sexual receptivity.
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Mahajan, Gulshan, Rajandeep Singh, and Bhagirath S. Chauhan. "Biology of Brassica tournefortii in the northern grains region of Australia." Crop and Pasture Science 71, no. 3 (2020): 268. http://dx.doi.org/10.1071/cp19451.
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Brassica tournefortii Gouan. (wild turnip, WT) has become a problematic weed in the no-till production systems of the northern grains region of Australia. Experiments were undertaken using different biotypes of B. tournefortii to examine its phenology, emergence and seedbank persistence. Biotypes were obtained from paddocks of barley (Hordeum vulgare L.) (WT1 and WT9) and chickpea (Cicer arietinum L.) (WT1/17 and WT2/17). Fresh seeds initially had high dormancy rates and persisted for a short period on the surface. Seedbank persistence increased with burial depth, with 39% of seeds remaining for WT1 and 5% for WT9 after 30 months at 2 cm depth. Persistence of buried seeds varied across biotypes; WT1/17 seedlings also emerged in the second growing season from 2 cm depth. Compared with buried seeds, seedlings readily emerged from the surface (in March–June following increased rainfall) within 6 months of planting. Emergence was greatest on the surface and varied between biotypes and tillage systems; the highest rate recorded was ~14%. Multiple cohorts were produced between February and October. No-till systems produced higher emergence rates than conventional tillage systems. Seedlings of B. tournefortii did not emerge from 5 cm soil depth; therefore, diligent tillage practices without seedbank replenishment could rapidly reduce the presence of this weed. A soil-moisture study revealed that at 25% of water-holding capacity, B. tournefortii tended to produce sufficient seeds for reinfestation in the field. Brassica tournefortii is a cross-pollinated species, and its wider emergence time and capacity to produce enough seeds in a dry environment enable it to become widespread in Australia. Early cohorts (March) tended to have vigorous growth and high reproduction potential. This study found B. tournefortii to be a poor competitor of wheat (Triticum aestivum L.), having greater capacity to compete with the slow-growing crop chickpea. Therefore, control of early-season cohorts and use of rotations with a more vigorous crop such as wheat may reduce the seedbank. The information gained in this study will be important in developing better understanding of seed ecology of B. tournefortii for the purpose of developing integrated management strategies.
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O’Hea Miller, Sarah B., Andrew R. Davis, and Marian Y. L. Wong. "Further Insights into Invasion: Field Observations of Behavioural Interactions between an Invasive and Critically Endangered Freshwater Crayfish Using Baited Remote Underwater Video (BRUV)." Biology 12, no. 1 (December 22, 2022): 18. http://dx.doi.org/10.3390/biology12010018.
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Competitive behavioural interactions between invasive and native freshwater crayfish are recognised as a key underlying mechanism behind the displacement of natives by invaders. However, in situ investigations into behavioural interactions between invasive and native crayfish are scarce. In Australian freshwater systems, the invasive Cherax destructor has spread into the ranges of many native Euastacus species, including the critically endangered Euastacus dharawalus. Staged contests between the two species in a laboratory setting found E. dharawalus to be the dominant competitor, however, this has yet to be corroborated in situ. Here, we used baited remote underwater video (BRUV) to examine in situ intra- and inter-specific behavioural interactions between E. dharawalus and C. destructor. We sought to evaluate patterns of dominance and differential contest dynamics between the species to provide indications of competition between the two species. We found E. dharawalus to be dominant over C. destructor based on pooled interspecific interaction data and size-grouped interactions where C. destructor was the smaller opponent. Alarmingly, however, when C. destructor was within a 10% size difference the dominance of E. dharawalus was lost, contrasting with the outcomes of the laboratory-staged study. In addition, we report that small C. destructor initiated significantly more contests than larger conspecifics and larger E. dharawalus, a pattern that was not observed in smaller E. dharawalus. Further, intraspecific interactions between C. destructor were significantly longer in duration than intraspecific interactions between E. dharawalus, indicating a willingness to continue fighting. Concerningly, these outcomes point towards inherent and greater aggressiveness in C. destructor relative to E. dharawalus and that only larger E. dharawalus hold a competitive advantage over C. destructor. Therefore, we conclude that C. destructor represents a substantial threat to E. dharawalus through competitive behavioural interactions. Further, due to the disparity between our findings and those produced from laboratory-staged contests, we recommend the use of in situ studies when determining the behavioural impacts of invasive crayfish on natives.
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Gao, Hui, Shuijing Zhai, Zhigao Sun, Juan Liu, and Chuan Tong. "Differences in biomass and silica content in typical plant communities with ecotones in the Min River estuary of southeast China." PeerJ 7 (July 22, 2019): e7218. http://dx.doi.org/10.7717/peerj.7218.
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Silica (Si) is a basic nutrient requirement for many aquatic organisms and its biogeochemical cycle plays an important role in estuarine coastal ecosystems. However, little is known about the role Si plays during plant–plant interactive processes in the marsh ecosystems. Here, variations in biomass, biogenic silica (BSi) content, and available Si content of Cyperus malaccensis-dominated marshes, Phragmites australis-dominated marshes, and their ecotonal marshes were studied in the Shanyutan marsh in the Min River estuary, China. Results showed that C. malaccensis and P. australis biomass in ecotones was lower than those in typical communities by 46.4% and 46.3%, respectively. BSi content in aboveground organs of C. malaccensis and culms and roots of P. australis was lower in ecotones than in typical communities, whereas BSi content in other organs showed the opposite trend. Biomass allocation in C. malaccensis and P. australis roots in ecotones was higher by 56.9% and 19.5%, respectively, and BSi stock in C. malaccensis and P. australis roots was higher than that in typical communities by 120.9% and 18.9%, respectively. Available Si content in ecotonal marsh soils was 12.6% greater than that in typical communities. Thus, the two plant species may use different strategies for Si accumulation and allocation in ecotones to adapt to the competitive environment. P. australis may expand primarily via occupation of wider aboveground space, thereby increasing the Si accumulation capacity in aboveground organs. Meanwhile, C. malaccensis may increase the Si allocation capacity of its roots to withstand the pressure from P. australis. This study will provide new insights into marsh plant competition from the perspective of Si, which can also benefit plant management in marsh ecosystems.
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Forrester, Neil W., Matthew Cahill, Lisa J. Bird, and Jacquelyn K. Layland. "Section 5. Pyrethroid and endosulfan resistance: biology of resistant and susceptible larvae and pupae." Bulletin of entomological research supplement series 1 (September 1993): 36–42. http://dx.doi.org/10.1017/s1367426900000114.
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SummaryBoth pyrethroid and endosulfan resistant Helicoverpa armigera larvae were shown to have marginally longer development times. Pyrethroid resistant larvae were slower developers often requiring an extra moult before ultimately pupating to the same size pupa as susceptibles. There were no differences between pyrethroid resistant and susceptible pupal development times (male or female). Laboratory and field competition studies could demonstrate no selective advantage for either pyrethroid resistant or susceptible larvae or prepupae. Thus it would seem that the slightly longer larval development times do not manifest as significant biological deficits. This helps explain the gradually deteriorating pyrethroid resistance situation documented during evaluation of the Australian insecticide resistance management (IRM) strategy. There was no evidence of the selection of fitness modifiers (co-adaptation) to overcome the slower development of either pyrethroid or endosulfan resistant larvae. Endosulfan fitness disadvantages were not sufficiently researched in this study to discount the possibility of a fitness deficit contributing to the much more successful management of endosulfan resistance.
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Cavers, Paul, Mirwais Qaderi, Paul Threadgill, and Marion Steel. "The Biology of Canadian Weeds. 147.Onopordum acanthiumL." Canadian Journal of Plant Science 91, no. 4 (July 2011): 739–58. http://dx.doi.org/10.4141/cjps10195.
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Cavers, P. B., Qaderi, M. M., Threadgill, P. F. and Steel, M. G. 2011. The Biology of Canadian Weeds. 147. Onopordum acanthium L. Can. J. Plant Sci. 91: 739–758. In Canada, Scotch thistle, Onopordum acanthium L. (Asteraceae) is primarily a weed of well-drained natural areas and ruderal habitats such as abandoned gravel pits. It is classed as a noxious weed in Ontario and the North Okanagan region of British Columbia but is common only in southern Ontario. Native to southern Europe and southwestern Asia, it has been introduced to almost 50 countries in all continents except Antarctica. In parts of the United States it is a strongly competitive species that infests small grain fields and competes with desirable forage species in rangelands. It does have desirable attributes and has many uses including being consumed as a vegetable, used as a source of honey, yielding a burnable oil, incorporated in medications for many human ailments, providing grazing for goats, sheep and cattle and being grown as a garden ornamental. Despite its limited range in Canada, several distinct biotypes, differing in morphology, phenology and important ecological attributes, such as dormancy and longevity of cypselas (fruits) in the soil, have been described from southern Ontario. In Australia, a fertile hybrid of O. acanthium and O. illyricum is a major weed and there are concerns that these two species could be progenitors of a similar hybrid in North America.
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Farrell, Hannah L., and Elise S. Gornish. "Pennisetum ciliare: a review of treatment efficacy, competitive traits, and restoration opportunities." Invasive Plant Science and Management 12, no. 4 (October 25, 2019): 203–13. http://dx.doi.org/10.1017/inp.2019.28.
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AbstractBuffelgrass [Pennisetum ciliare (L.) Link] is a drought-tolerant invasive grass that is a threat to native biodiversity in the drylands of the Americas and Australia. Despite efforts from land managers to control P. ciliare, management approaches tend to have mixed success, treatment results can be poorly communicated among entities, and there are few long-term controlled studies. In this literature review, we synthesize data from both peer-reviewed and “gray” literature on the efficacy of management techniques to control P. ciliare and the secondary impacts to native plant communities. Our search resulted in 42 unique sources containing a total of 229 studies that we categorized into 10 treatment types, which included herbicide, seeding, manual removal, fire, grazing, biocontrol, fire + additional treatments, manual removal + additional treatments, herbicide + additional treatments, and herbicide + manual removal. We found that treatments that used multiple techniques in tandem along with follow-up treatments were the most effective at controlling P. ciliare. Fewer than one-third of the studies reported impacts of management on native species, and the most commonly studied treatment (herbicide, N = 130) showed detrimental impacts on native plant communities. However, the average time between treatment and outcome measurement was only 15 mo; we suggest the need for more long-term studies of treatment efficacy and secondary impacts of treatment on the ecosystem. Finally, we conducted a second literature review on P. ciliare biology and traits for mechanisms that allows P. ciliare to alter the invaded environment to facilitate a competitive advantage over native species. We found evidence of self-reinforcing feedbacks of invasion being generated by P. ciliare through its interactions with water availability, nutrient cycling, and disturbance regimes. We developed a conceptual model of P. ciliare based on these feedback loops and offer management considerations based on its invasion dynamics and biology.
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Warwick, Suzanne I., and Ardath Francis. "The biology of Canadian weeds. 132. Raphanus raphanistrum L." Canadian Journal of Plant Science 85, no. 3 (July 1, 2005): 709–33. http://dx.doi.org/10.4141/p04-120.
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A review of biological information is provided for Raphanus raphanistrum L. Native to the Mediterranean region, the species is widely introduced and naturalized in temperate regions around the world. In Canada, it currently occurs in all provinces except Saskatchewan and Manitoba, has only a limited distribution in Alberta, and is also absent from the Yukon, the Northwest Territories and Nunavut. It is most abundant in the Atlantic and Pacific regions and is an important weed of field crops in the Maritime provinces and Quebec. A persistent seed bank, competitive annual growth habit and high fecundity all contribute to its weedy nature and ensure that it will be a continuing problem. It can easily hybridize with cultivated radish, R. sativus L., and commonly does so when they occur together. Limited hybridization with canola, Brassica napus L., has been reported from several experimental field and greenhouse trials. Selective herbicide control is most difficult in canola and other cruciferous crops. It is the most important dicot weed in the southwestern region of Australia, primarily due to the evolution of several different herbicide-resistant biotypes. These include biotypes resistant to the acetolactate synthase (ALS)-inhibitors (group 2 herbicides) and/or photosystem II-inhibitors (group 5), and a biotype with multiple resistance to ALS-inhibitors, photosystem II-inhibitors, an auxin (2,4-D amine), and a phytoene desaturase (PSDS)-inhibitor (diflufenican). A biotype resistant to the ALS-inhibiting herbicide chlorsulfuron has also been detected in South Africa. Key words: Wild radish, Raphanus raphanistrum, herbicide resistance, canola, hybridization, RAPRA
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Connor, Jonathan D., Ian Renshaw, and Kenji Doma. "Moderating factors influence the relative age effect in Australian cricket." PeerJ 7 (May 17, 2019): e6867. http://dx.doi.org/10.7717/peerj.6867.
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Background The relative age effect is a commonly occurring phenomenon whereby there is a tendency for relatively older players to be over-represented during high level competitions. This effect is often seen to diminish as player’s age, however, there has been far less investigation on other potential moderating factors. Method This study investigated the impact of the relative age effect, and potential moderating factors, within the talent selection process of Australian cricket. Relative age distribution of 2,415 male and female junior and senior state level cricket players, who played in the Junior National Championships or State competition (senior level) between 2011 and 2015, were analysed. Results Players born in the first quartile of the cricket season were significantly over-represented in both male Under-15, Under-17, Under-19 and female Under-15 and Under-18 levels. However, there was no significant difference at the senior state level for either male or female cricketers. Further investigation of the relative age effect in the junior talent pathway revealed that male all-rounders, batters and pace bowlers, and female all-rounders and batters, born in first quartile were over-represented. Right-handed batters and bowlers were also influenced by the relative age effect at all Junior National levels, while left-handed batters and bowlers were only influenced at the Under-15 and Under-17 levels. These results highlight the impact relative age has on junior cricket talent pathways, including sex, age, handedness and primary skills. Only state level, and left-handedness at the Under-19 level, were unaffected by relative age. Discussion The findings of this study highlight the influence of relative age effects for both male and female junior cricket players. Interestingly, there may be an advantage to being left-handed that is more prevalent at the older (male Under-19; female Under-18) age levels.
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Wijayabandara, Kusinara, Shane Campbell, Joseph Vitelli, Asad Shabbir, and Steve Adkins. "Review of the Biology, Distribution, and Management of the Invasive Fireweed (Senecio madagascariensis Poir)." Plants 11, no. 1 (December 30, 2021): 107. http://dx.doi.org/10.3390/plants11010107.
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Whilst exotic invasive species are a major threat to natural and modified ecosystems around the world, management programs to reduce their impacts often fail due to a lack of information about their biology and how best to control them in various situations. This paper reviews the currently available information on the biology, distribution, and management options for the invasive weed Senecio madagascariensis Poir. (fireweed). In addition, we developed a model to predict the climatic suitability of this weed around the world based on the current climate. Senecio madagascariensis originates from southern Africa but it has been introduced to several other countries including Australia. Climatic suitability suggests that there are large areas around the world suitable for the weed’s growth where it is currently not present. The weed poses a major threat to livestock industries in these countries through its ability to reduce pasture production and poison animals. A range of control techniques have been used to try and manage S. madagascariensis. This paper highlights how a better understanding of the biology of S. madagascariensis can help determine the most effective treatments to impose and to further develop integrated management strategies. Besides using traditional approaches, the use of competitive pastures and more tolerant livestock (such as sheep and goats) are some of the other options recommended as part of an integrated approach. On-going research to identify host-specific biological control agents is also considered a priority.
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Lamont, Byron B., Neal J. Enright, E. T. F. Witkowski, and J. Groeneveld. "Conservation biology of banksias: insights from natural history to simulation modelling." Australian Journal of Botany 55, no. 3 (2007): 280. http://dx.doi.org/10.1071/bt06024.
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We have studied the ecology and conservation requirements of Banksia species in the species-rich sandplains of south-western Australia for 25 years. Loss of habitat through land-clearing has had the greatest impact on their conservation status over the last 50 years. Ascertaining optimal conditions for conservation management in bushland requires detailed knowledge of the species under consideration, including demographic attributes, fire regime, growing conditions and interactions with other species. Where populations have been fragmented, seed production per plant has also fallen. The group most vulnerable to the vagaries of fire, disease, pests, weeds and climate change are the non-sprouters, rather than the resprouters, with population extinction so far confined to non-sprouting species. Recent short-interval fires (<8 years) appear to have had little impact at the landscape scale, possibly because they are rare and patchy. Fire intervals exceeding 25–50 years can also lead to local extinction. Up to 200 viable seeds are required for parent replacement in Banksia hookeriana when growing conditions are poor (low post-fire rainfall, commercial flower harvesting) and seed banks of this size can take up to 12 years to be reached. Seed production is rarely limited by pollinators, but interannual seasonal effects and resource availability are important. Genetic diversity of the seed store is quickly restored to the level of the parents in B. hookeriana. Florivores and granivores generally reduce seed stores, although this varies markedly among species. In Banksia tricuspis, black cockatoos actually increase seed set by selectively destroying borers. Potential loss of populations through the root pathogen Phytophthora cinnamomi also challenges management, especially in the southern sandplains. Prefire dead plants are a poor source of seeds for the next generation when fire does occur. Harvesting seeds and sowing post-fire have much to commend them for critically endangered species. Bare areas caused by humans can result in ideal conditions for plant growth and seed set. However, in the case of B. hookeriana/B. prionotes, disturbance by humans has fostered hybridisation, threatening the genetic integrity of both species, whereas fine-textured soils are unsuitable for colonisation or rehabilitation. Few viable seeds become seedlings after fire, owing to post-release granivory and herbivory and unsuitable germination conditions. Seedling-competitive effects ensure that season/intensity of fire is not critical to recruitment levels, except in the presence of weeds. Water availability during summer–autumn is critical and poses a problem for conservation management if the trend for declining rainfall in the region continues. Our simulation modelling for three banksias shows that the probability of co-occurrence is maximal when fire is stochastic around a mean of 13 years, and where fire-proneness and post-fire recruitment success vary in the landscape. Modelling results suggest that non-sprouting banksias could not survive the pre-European frequent-fire scenario suggested by the new grasstree technique for south-western Australia. However, we have yet to fully explore the conservation significance of long-distance dispersal of seeds, recently shown to exceed 2.5 km in B. hookeriana.
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West, Rebecca, John Llewellyn Read, Matthew James Ward, Wendy K. Foster, and David A. Taggart. "Monitoring for adaptive management in a trial reintroduction of the black-footed rock-wallabyPetrogale lateralis." Oryx 51, no. 3 (April 5, 2016): 554–63. http://dx.doi.org/10.1017/s0030605315001490.
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AbstractReintroduction practitioners must often make critical decisions about reintroduction protocols despite having little understanding of the reintroduction biology of the focal species. To enhance the available knowledge on the reintroduction biology of the warru, or black-footed rock-wallabyPetrogale lateralisMacDonnell Ranges race, we conducted a trial reintroduction of 16 captive individuals into a fenced predator and competitor exclosure on the An̲angu Pitjantjatjara Yankunytjatjara Lands in South Australia. We conducted seven trapping sessions and used radio-tracking and camera traps to monitor survival, reproduction and recruitment to the population over 36 months. Blood samples were collected pre-release and during two trapping sessions post-release to assess nutritional health. The survival rate of founders was 63%, with all losses occurring within 10 weeks of release. Post-release blood biochemistry indicated that surviving warru adapted to their new environment and food sources. Female warru conceived within 6 months of release; 28 births were recorded during the study period and 52% of births successfully recruited to the population. Our results suggest that captive-bred warru are capable of establishing and persisting in the absence of introduced predators. However, the high mortality rate immediately post-release, with only a modest recruitment rate, suggests that future releases into areas where predators and competitors are present should use a trial approach to determine the viability of reintroduction. We recommend that future releases of warru into unfenced areas include an intensive monitoring period in the first 3 months post-release followed by a comprehensive long-term monitoring schedule to facilitate effective adaptive management.
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Toop, T., D. Grozdanovski, and I. C. Potter. "Natriuretic peptide binding sites in the gills of the pouched lamprey Geotria australis." Journal of Experimental Biology 201, no. 11 (June 1, 1998): 1799–808. http://dx.doi.org/10.1242/jeb.201.11.1799.
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Iodinated atrial natriuretic peptide (ANP) binding sites were examined in the gills and ventral aorta of the adult upstream-migrating lamprey Geotria australis using tissue section autoradiography, in vitro competition analysis and affinity cross-linking, while guanylate cyclase assays were performed on gill membranes of both adult and juvenile lampreys. A partial natriuretic peptide (NP) receptor sequence was amplified using reverse transcription/polymerase chain reaction (RT-PCR). The results indicated that there was specific NP binding to the aortic endothelium and to pillar cell regions in the axial plate and secondary lamellae. In competition studies, 50 % of NP binding was abolished by 4 nmol l-1 rat ANP, 35 nmol l-1 porcine C-type NP (CNP) and 45 nmol l-1 C-ANF (a truncated ANP). Affinity cross-linking followed by SDS-PAGE demonstrated two binding sites at 205 and 65 kDa under non-reducing conditions and at 85 and 65 kDa under reducing conditions. Guanylate cyclase assays demonstrated that, while no NP-stimulated GC activity occurred in adult lampreys, NP-stimulated enhancement of cyclic GMP accumulation was found in juveniles in fresh water and more particularly in salt water. RT-PCR amplified a 471 base pair fragment with 68 % amino acid sequence homology to the eel natriuretic peptide receptor D (NPR-D). This study suggests that NP binding sites in the adult gill and aorta are of an NPR-C/D type, whereas an additional GC-coupled site exists in juveniles.
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Crossland, Michael R., Takashi Haramura, Angela A. Salim, Robert J. Capon, and Richard Shine. "Exploiting intraspecific competitive mechanisms to control invasive cane toads ( Rhinella marina )." Proceedings of the Royal Society B: Biological Sciences 279, no. 1742 (June 13, 2012): 3436–42. http://dx.doi.org/10.1098/rspb.2012.0821.
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If invasive species use chemical weapons to suppress the viability of conspecifics, we may be able to exploit those species-specific chemical cues for selective control of the invader. Cane toads ( Rhinella marina ) are spreading through tropical Australia, with negative effects on native species. The tadpoles of cane toads eliminate intraspecific competitors by locating and consuming newly laid eggs. Our laboratory trials show that tadpoles find those eggs by searching for the powerful bufadienolide toxins (especially, bufogenins) that toads use to deter predators. Using those toxins as bait, funnel-traps placed in natural waterbodies achieved near-complete eradication of cane toad tadpoles with minimal collateral damage (because most native (non-target) species are repelled by the toads' toxins). More generally, communication systems that have evolved for intraspecific conflict provide novel opportunities for invasive-species control.
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Haskett, Timothy L., Jason J. Terpolilli, Amanuel Bekuma, Graham W. O’Hara, John T. Sullivan, Penghao Wang, Clive W. Ronson, and Joshua P. Ramsay. "Assembly and transfer of tripartite integrative and conjugative genetic elements." Proceedings of the National Academy of Sciences 113, no. 43 (October 12, 2016): 12268–73. http://dx.doi.org/10.1073/pnas.1613358113.
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Integrative and conjugative elements (ICEs) are ubiquitous mobile genetic elements present as “genomic islands” within bacterial chromosomes. Symbiosis islands are ICEs that convert nonsymbiotic mesorhizobia into symbionts of legumes. Here we report the discovery of symbiosis ICEs that exist as three separate chromosomal regions when integrated in their hosts, but through recombination assemble as a single circular ICE for conjugative transfer. Whole-genome comparisons revealed exconjugants derived from nonsymbiotic mesorhizobia received three separate chromosomal regions from the donorMesorhizobium ciceriWSM1271. The three regions were each bordered by two nonhomologous integrase attachment (att) sites, which together comprised three homologous pairs ofattLandattRsites. Sequential recombination between eachattLandattRpair produced correspondingattPandattBsites and joined the three fragments to produce a single circular ICE, ICEMcSym1271. A plasmid carrying the threeattPsites was used to recreate the process of tripartite ICE integration and to confirm the role of integrase genesintS,intM, andintGin this process. Nine additional tripartite ICEs were identified in diverse mesorhizobia and transfer was demonstrated for three of them. The transfer of tripartite ICEs to nonsymbiotic mesorhizobia explains the evolution of competitive but suboptimal N2-fixing strains found in Western Australian soils. The unheralded existence of tripartite ICEs raises the possibility that multipartite elements reside in other organisms, but have been overlooked because of their unusual biology. These discoveries reveal mechanisms by which integrases dramatically manipulate bacterial genomes to allow cotransfer of disparate chromosomal regions.
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King, Carolyn. "Abundance and Dynamics of Small Mammals in New Zealand: Sequential Invasions into an Island Ecosystem Like No Other." Life 13, no. 1 (January 5, 2023): 156. http://dx.doi.org/10.3390/life13010156.
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New Zealand had no people or four-footed mammals of any size until it was colonised by Polynesian voyagers and Pacific rats in c. 1280 AD. Between 1769 and 1920 AD, Europeans brought three more species of commensal rats and mice, and three predatory mustelids, plus rabbits, house cats hedgehogs and Australian brushtail possums. All have in turn invaded the whole country and many offshore islands in huge abundance, at least initially. Three species are now reduced to remnant populations, but the other eight remain widely distributed. They comprise an artificial but interacting and fully functional bottom-up predator-prey system, responding at all levels to interspecific competition, habitat quality and periodic resource pulsing.
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Janke, Chelsea K., Laura A. Wendling, and Ryosuke Fujinuma. "Biological nitrification inhibition by root exudates of native species,Hibiscus splendensandSolanum echinatum." PeerJ 6 (June 19, 2018): e4960. http://dx.doi.org/10.7717/peerj.4960.
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Australian native species grow competitively in nutrient limited environments, particularly in nitrogen (N) limited soils; however, the mechanism that enables this is poorly understood. Biological nitrification inhibition (BNI), which is the release of root exudates into the plant rhizosphere to inhibit the nitrification process, is a hypothesized adaptive mechanism for maximizing N uptake. To date, few studies have investigated the temporal pattern and components of root exudates by Australian native plant species for BNI. This study examined root exudates from two Australian native species,Hibiscus splendensandSolanum echinatum,and contrasted with exudates ofSorghum bicolor, a plant widely demonstrated to exhibit BNI capacity. Root exudates were collected from plants at two, four, and six weeks after transplanting to solution culture. Root exudates contained three types of organic acids (OAs), oxalic, citric and succinic acids, regardless of the species. However, the two Australian natives species released larger amount of OAs in earlier development stages thanS. bicolor. The total quantity of these OAs released per unit root dry mass was also seven-ten times greater for Australian native plant species compared toS. bicolor. The root exudates significantly inhibited nitrification activity over six weeks’ growth in a potential nitrification assay, withS. echinatum(ca. 81% inhibition) >S. bicolor(ca. 80% inhibition) >H. splendens(ca. 78% inhibition). The narrow range of BNI capacity in the study plants limited the determination of a relationship between OAs and BNI; however, a lack of correlation between individual OAs and inhibition of nitrification suggests OAs may not directly contribute to BNI. These results indicate that Australian native species generate a strongly N conserving environment within the rhizosphere up to six weeks after germination, establishing a competitive advantage in severely N limited environments.
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Dai, Lingjun, Hongyu Liu, Gang Wang, Cheng Wang, Ziru Guo, Yi Zhou, and Yufeng Li. "Modelling the effects of Spartina alterniflora invasion on the landscape succession of Yancheng coastal natural wetlands, China." PeerJ 8 (November 24, 2020): e10400. http://dx.doi.org/10.7717/peerj.10400.
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Background The Yancheng coastal natural wetlands (YCNR) are well-preserved silty tidal flat wetlands in China. Due to the severe invasion of Spartina alterniflora, the native ecosystem has undergone great changes. The successful invasion of S. alterniflora reduced the biodiversity of the YCNR, changed the structure and function of the local ecosystem, and eventually led to the degradation of the ecosystem and the loss of ecosystem function and service. Fully understanding the impact of an alien species invasion on YCNR succession is an important prerequisite for protecting and restoring the wetlands. Methods In this study, remote sensing, GIS technology, and a cellular-automaton Markov model were used to simulate the natural succession process of native ecosystems without being affected by alien species. By comparing the landscape of the YCNR with the model simulation results, we gained a better understanding of how alien species affect native landscape-scale ecosystems. Results During the natural succession of the coastal native wetland ecosystem in the YCNR, the pioneer species S. alterniflora occupied the mudflats and expanded seaward. The whole area expanded and moved seaward with an average annual movement of 58.23 m. Phragmites australis seemed to dominate the competition with S. salsa communities, and the area gradually expanded with an average annual movement of 39.89 m. The invasion of S. alterniflora changed the native ecosystem’s spatial succession process, causing the S. salsa ecosystem to be stressed by ecosystems on the side of the sea (S. alterniflora) and that of land (P. australis). The area of the seaward-expanding P. australis ecosystem has been declining. Under a reasonable protected area policy, human activities have enhanced the succession rate of the P. australis ecosystem and have had a small impact on the ecological spatial succession of S. salsa and S. alterniflora.
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Narendra, Ajay, Samuel F. Reid, Birgit Greiner, Richard A. Peters, Jan M. Hemmi, Willi A. Ribi, and Jochen Zeil. "Caste-specific visual adaptations to distinct daily activity schedules in Australian Myrmecia ants." Proceedings of the Royal Society B: Biological Sciences 278, no. 1709 (October 6, 2010): 1141–49. http://dx.doi.org/10.1098/rspb.2010.1378.
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Animals are active at different times of the day and their activity schedules are shaped by competition, time-limited food resources and predators. Different temporal niches provide different light conditions, which affect the quality of visual information available to animals, in particular for navigation. We analysed caste-specific differences in compound eyes and ocelli in four congeneric sympatric species of Myrmecia ants, with emphasis on within-species adaptive flexibility and daily activity rhythms. Each caste has its own lifestyle: workers are exclusively pedestrian; alate females lead a brief life on the wing before becoming pedestrian; alate males lead a life exclusively on the wing. While workers of the four species range from diurnal, diurnal-crepuscular, crepuscular-nocturnal to nocturnal, the activity times of conspecific alates do not match in all cases. Even within a single species, we found eye area, facet numbers, facet sizes, rhabdom diameters and ocelli size to be tuned to the distinct temporal niche each caste occupies. We discuss these visual adaptations in relation to ambient light levels, visual tasks and mode of locomotion.
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Stankovic, Z., M. Borisev, Slobodanka Simic, Milijana Vuckovic, Ruzica Igic, Milka Vidovic, and B. Miljanovic. "Macrophytes of the Grliste reservoir (Serbia): Fifteen years after its establishment." Archives of Biological Sciences 61, no. 2 (2009): 267–78. http://dx.doi.org/10.2298/abs0902267s.
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A large number of macrophytes, often in dense populations, have developed on the Grliste Reservoir, Serbia over a period of 15 years. Fast development of vegetation is a consequence of anthropogenic impact in lake management. The methodology used in this research covered 100% of the water body, including all areas with or without aquatic plants. The results indicate that plant communities are still in the early phase of development. This leaves space for future development of competitor macrophyte species (Najas marina, Eleocharis palustris, Typha latifolia, Typha angustifolia, Phragmites australis, etc.) capable of endangering stability of the lake, which will tend toward eutrophication.
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Legault, Rene, Gregory P. Zogg, and Steven E. Travis. "Competitive interactions between native Spartina alterniflora and non-native Phragmites australis depend on nutrient loading and temperature." PLOS ONE 13, no. 2 (February 1, 2018): e0192234. http://dx.doi.org/10.1371/journal.pone.0192234.
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McLennan, Hanna J., Stefan Lüpold, Pete Smissen, Kevin C. Rowe, and William G. Breed. "Greater sperm complexity in the Australasian old endemic rodents (Tribe: Hydromyini) is associated with increased levels of inter-male sperm competition." Reproduction, Fertility and Development 29, no. 5 (2017): 921. http://dx.doi.org/10.1071/rd15425.
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Spermatozoa exhibit considerable interspecies morphological variation across mammals, especially among murid rodents. In Australasia, most murids in the tribe Hydromyini have a spermatozoon with a highly complex head exhibiting an apical hook, characteristic of most murids, and two projections that extend from its upper concave surface, the ventral processes. In the present study we performed a phylogenetically controlled comparison of sperm morphology across 45 species of hydromyine rodents to test the hypothesis that the length and angle of both the apical hook and ventral processes, as well as the length of the sperm tail, increase with relative testes mass as a proxy for differences in levels of inter-male sperm competition. Although both sperm head protrusions exhibited considerable variation in their length and angle across species, only the angles increased significantly in relation to relative testes mass. Further, the length of the sperm flagellum was positively associated with relative testes mass. These results suggest that, in hydromyine rodents, the angle of the apical hook and ventral processes of the sperm head, as well as the sperm tail length, are likely to be sexually selected traits. The possible functional significance of these findings is briefly discussed.
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Brandenburger, Claire R., William B. Sherwin, Stephanie M. Creer, Robert Buitenwerf, Alistair G. B. Poore, Richard Frankham, Patrick B. Finnerty, and Angela T. Moles. "Rapid reshaping: the evolution of morphological changes in an introduced beach daisy." Proceedings of the Royal Society B: Biological Sciences 286, no. 1897 (February 20, 2019): 20181713. http://dx.doi.org/10.1098/rspb.2018.1713.
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Thousands of species have been introduced to new ranges worldwide. These introductions provide opportunities for researchers to study evolutionary changes in form and function in response to new environmental conditions. However, almost all previous studies of morphological change in introduced species have compared introduced populations to populations from across the species' native range, so variation within native ranges probably confounds estimates of evolutionary change. In this study, we used microsatellites to locate the source population for the beach daisy Arctotheca populifolia that had been introduced to eastern Australia. We then compared four introduced populations from Australia with their original South African source population in a common-environment experiment. Despite being separated for less than 100 years, source and introduced populations of A. populifolia display substantial heritable morphological differences. Contrary to the evolution of increased competitive ability hypothesis, introduced plants were shorter than source plants, and introduced and source plants did not differ in total biomass. Contrary to predictions based on higher rainfall in the introduced range, introduced plants had smaller, thicker leaves than source plants. Finally, while source plants develop lobed adult leaves, introduced plants retain their spathulate juvenile leaf shape into adulthood. These changes indicate that rapid evolution in introduced species happens, but not always in the direction predicted by theory.
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Scheepers, L., and G. Jones. "AB0414 DRUG PERSISTENCE ON JANUS KINASE (JAK) INHIBITORS COMPARED TO BIOLOGIC DMARDs IN PATIENTS WITH RHEUMATOID ARTHRITIS: RETROSPECTIVE STUDY IN THE AUSTRALIAN POPULATION." Annals of the Rheumatic Diseases 81, Suppl 1 (May 23, 2022): 1335.2–1335. http://dx.doi.org/10.1136/annrheumdis-2022-eular.4149.
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BackgroundIn rheumatoid arthritis (RA) persistence on disease modifying anti-rheumatic drugs (DMARDs) can be interpreted as a composite measure of effectiveness, safety, and tolerability. There is limited data available on real-life use of the newest class of drugs, the Janus Kinase (JAK) inhibitors. JAK inhibitors are small-molecule treatments which are administered orally on a daily basis and offer a long-term option in RA treatment.ObjectivesTo compare drug persistence on JAK inhibitors tofacitinib, baricitinib and upadacitinib to tumor necrosis factor-α (TNF) inhibitors and other DMARDs in RA patients in Australia.MethodsA retrospective observational study was conducted among RA patients in the Australian Medicare Database (from January 2006 till October 2021), aged ≥18 and for whom a JAK inhibitor or biologic DMARDs were dispensed. Data were provided by the Australian Department of Health and Aging through PROSPECTION, an Australian healthcare consulting company. A deidentified 10% sample of the database was taken as a random representation of RA patients in Australia.Kaplan-Meier analysis was used to calculate drug persistence rates, defined as the time from treatment initiation until the date of the last dose when there had not been a script dispensed for 6 months; except for rituximab, where a 12-month gap was applied.ResultsData from 5,455 patients were analysed. For all patients the 12-month persistence rates were 61% for JAK inhibitors (baricitinib, tofacitinib, upadacitinib), 62% for tocilizumab, 52% for TNF inhibitors (adalimumab, certolizumab, etanercept, golimumab, infliximab), and 51% for abatacept. The JAK inhibitors baricitinib (64%) and upadacitinib (78%) were superior to tofacitinib (54%). Median treatment persistence for upadacitinib was not reached (n = 430); was 27.1 months for baricitinib and 15.2 months for tofacitinib. For TNF inhibitors, treatment persistence was 15.1 months for adalimumab, 14.1 months for certolizumab, 14.0 months for etanercept, 11.1 months for golimumab and 4.5 months for infliximab.Persistence rates on first-line JAK inhibitors were 70% for baricitinib and 57% for tofacitinib; persistence rates dropped to 63% for baricitinib and 47% for tofacitinib in the second-line setting. First-line persistence rates were 54% for TNF inhibitors and 65% for tocilizumab, rates were sustained for tocilizumab, but dropped to 48% for TNF inhibitors in the second-line setting.ConclusionThis real-world data highlights that in an Australian clinical practice setting treatment persistence rates on 12 months on JAK inhibitors, in particular baricitinib and upadacitinib, were superior to TNF inhibitors, but not to tocilizumab. Suggesting that persistence rates might differ according to biologics mode of action and line of treatment.Table 1.Persistence rates at 12 months post treatment initiationAll patientsFirst lineSecond lineJAK inhibitorsOverall61% (2155)60% (616)60% (554)Baricitinib64% (537)70% (158)63% (124)Tofacitinib54% (1188)57% (441)47% (294)Upadacitinib78% (430)28% (17)84% (136)TNF inhibitorsOverall52% (6339)54% (4227)48% (1561)Adalimumab55% (2710)56% (2030)48% (590)Certolizumab51% (593)54% (251)47% (147)Etanercept52% (2079)55% (1354)47% (623)Golimumab49% (814)49% (506)47% (174)Infliximab35% (143)23% (86)53% (27)Other DMARDsAbatacept51% (952)56% (263)46% (310)Rituximab49% (284)41% (70)65% (79)Tocilizumab62% (1156)65% (279)65% (351)In brackets are number of patients.References[1]Hetland, M.L., et al., Direct comparison of treatment responses, remission rates, and drug adherence in patients with rheumatoid arthritis treated with adalimumab, etanercept, or infliximab: results from eight years of surveillance of clinical practice in the nationwide Danish DANBIO registry. Arthritis Rheum, 2010[2]Jones, G., et al., A retrospective review of the persistence on bDMARDs prescribed for the treatment of rheumatoid arthritis in the Australian population. Int J Rheum Dis, 2018AcknowledgementsL. Scheepers receives funding from The Farrell Family Foundation.Disclosure of InterestsLieke Scheepers Grant/research support from: received the Competitive Grant Program InflammationASPIRE 2020 Rheumatology International Developed Markets from Pfizer, Employee of: worked as an Associate Director Epidemiology at the Medical Evidence Observational Research Department at AstraZeneca., Graeme Jones Speakers bureau: Received payment for a speakers bureau from Novartis
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Kon, KF, and WM Blacklow. "Polymorphism, Outcrossing and Polyploidy in Bromus diandrus and B. rigidus." Australian Journal of Botany 38, no. 6 (1990): 609. http://dx.doi.org/10.1071/bt9900609.
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The genetic systems of Brornus diandrus Roth (great brome) and B. rigidus Roth (rigid brome) were studied in 30 populations sampled from Western Australia. Populations of B. diandrus were polymorphic and the dominant phenotype had scabrid lemmas and glabrous paleas. Polymorphs of B. rigidus had short and long awns with flat seeds and long awns with round seeds: all these phenotypes had scabrid lemmas and hairy paleas. Frequencies of the polymorphs varied between sites and years. Palea hairiness of B. diandrus is controlled by a single, dominant gene and was used as a marker gene for estimations of outcrossing frequencies and population homozygosis. B. diandrus is self-compatible and inbreeding with outcrossing frequencies less than 1%. Florets of both species were facultatively cleistogamous; there were high levels of chasmogamy in irrigated populations but most anthers had dehisced prior to exsertion. The high proportion of seed set in cleistogamous florets and similar floral biology suggested that the breeding system of B. rigidus was similar to that of B. diandrus. There was no evidence of species hybrids in the field and attempts at hybridisation failed. Populations of these species were homozygotic for a few major genotypes. Meiotic chromosomes of both species and all biotypes formed mainly bivalents and a few quadrivalents at metaphase I. This, together with the high proportion (Ͱ5 98%) of fertile pollen grains and the 3 : 1 segregation of hairy: glabrous paleas in selfed F2 progenies, indicated that inheritance in these species was disomic. The genomic formula proposed for B. diandrus is either AABBCCDD or AAAABBCC. The properties of polymorphism, autogamy and disomic inheritance within polyploidy would favour the development of tolerance to herbicides within populations, provided selected genotypes were competitive.