Science and Conservation Division
Science and Conservation Division
Davis J.,Charles Darwin University |
Sim L.,University of Canberra |
Thompson R.M.,University of Canberra |
Pinder A.,Science and Conservation Division |
And 4 more authors.
Ecography | Year: 2017
Managing and restoring faunal diversity across large areas requires an understanding of the roles of connectivity and dispersal in driving community patterns. We sought to determine the influence of connectivity, water regime, water source, geographical location, and dispersal traits on patterns of aquatic invertebrate diversity across a continent-wide arid biome. We compiled data on freshwater invertebrate assemblages from sites spanning the breadth of arid Australia. Univariate analyses (analysis of variance and rarefaction) revealed that alpha and gamma diversity across sites decreased as latitude increased. Multivariate analyses (ordination and analysis of similarity) revealed that community composition had considerable fidelity to geographic regions. Hydrological connectivity was strongly associated with riverine community composition although water rarely flowed (often less than annually). Hydrologically isolated sites (springs and rockholes) supported communities that were markedly dissimilar to hydrologically connected sites, and to each other. We investigated the influence of dispersal on diversity patterns by examining distance decay relationships for each of four dispersal trait groups (obligate aquatic and passive, weak, and strong aerial dispersers) on the basis of geodesic (shortest path) distances between pairs of sites and Mantel tests. We did not detect clear differences between dispersal traits and distance decay relationships at the continental scale, even for the two groups with the lowest dispersal ability (obligate aquatics and passive dispersers). Our results suggest that the loss of hydrological connectivity from water developments in arid lands (for example, the impoundment of intermittent rivers) is likely to affect macroinvertebrates. However, the exact flow mechanisms underlying such changes remain to be determined. © 2016 Nordic Society Oikos.
Doherty T.S.,Edith Cowan University |
Davis R.A.,Edith Cowan University |
van Etten E.J.B.,Edith Cowan University |
Algar D.,Science and Conservation Division |
And 5 more authors.
Journal of Biogeography | Year: 2015
Aim: Reducing the impacts of feral cats (Felis catus) is a priority for conservation managers across the globe, and success in achieving this aim requires a detailed understanding of the species' ecology across a broad spectrum of climatic and environmental conditions. We reviewed the diet of the feral cat across Australia and on Australian territorial islands, seeking to identify biogeographical patterns in dietary composition and diversity, and use the results to consider how feral cats may best be managed. Location: Australia and its territorial islands. Methods: Using 49 published and unpublished data sets, we modelled trophic diversity and the consumption of eight food groups against latitude, longitude, mean temperature, precipitation, environmental productivity and climate-habitat regions. Results: We recorded 400 vertebrate species that feral cats feed on or kill in Australia, including 28 IUCN Red List species. We found evidence of continental-scale prey-switching from rabbits to small mammals, previously recorded only at the local scale. The consumption of arthropods, reptiles, rabbits, rodents and medium-sized native mammals varied with different combinations of latitude, longitude, mean annual precipitation, temperature and environmental productivity. The frequency of rodents and dasyurids in cats' diets increased as rabbit consumption decreased. Main conclusions: The feral cat is an opportunistic, generalist carnivore that consumes a diverse suite of vertebrate prey across Australia. It uses a facultative feeding strategy, feeding mainly on rabbits when they are available, but switching to other food groups when they are not. Control programmes aimed at culling rabbits could potentially decrease the availability of a preferred food source for cats and then lead to greater predation pressure on native mammals. The interplay between cat diet and prey species diversity at a continental scale is complex, and thus cat management is likely to be necessary and most effective at the local landscape level. © 2015 John Wiley & Sons Ltd.
PubMed | Science and Conservation Division, Rhodes College and St. John's University
Type: Journal Article | Journal: PloS one | Year: 2016
Core Goodeniaceae is a clade of ~330 species primarily distributed in Australia. Considerable variation in flower morphology exists within this group and we aim to use geometric morphometrics to characterize this variation across the two major subclades: Scaevola sensu lato (s.l.) and Goodenia s.l., the latter of which was hypothesized to exhibit greater variability in floral symmetry form. We test the hypothesis that floral morphological variation can be adequately characterized by our morphometric approach, and that discrete groups of floral symmetry morphologies exist, which broadly correlate with subjectively determined groups. From 335 images of 44 species in the Core Goodeniaceae, two principal components were computed that describe >98% of variation in all datasets. Increasing values of PC1 ventralize the dorsal petals (increasing the angle between them), whereas increasing values of PC2 primarily ventralize the lateral petals (decreasing the angle between them). Manipulation of these two morphological axes alone was sufficient to recreate any of the general floral symmetry patterns in the Core Goodeniaceae. Goodenia s.l. exhibits greater variance than Scaevola s.l. in PC1 and PC2, and has a significantly lower mean value for PC1. Clustering clearly separates fan-flowers (with dorsal petals at least 120 separated) from the others, whereas the distinction between pseudo-radial and bilabiate clusters is less clear and may form a continuum rather than two distinct groups. Transitioning from the average fan-flower to the average non-fan-flower is described almost exclusively by PC1, whereas PC2 partially describes the transition between bilabiate and pseudo-radial morphologies. Our geometric morphometric method accurately models Core Goodeniaceae floral symmetry diversity.
Dunlop J.,Science and Conservation Division |
Dunlop J.,Murdoch University |
Thompson C.K.,Murdoch University |
Godfrey S.S.,Murdoch University |
Thompson R.C.A.,Murdoch University
Experimental Parasitology | Year: 2014
Automated extraction of DNA for testing of laboratory samples is an attractive alternative to labour-intensive manual methods when higher throughput is required. However, it is important to maintain the maximum detection sensitivity possible to reduce the occurrence of type II errors (false negatives; failure to detect the target when it is present), especially in the biomedical field, where PCR is used for diagnosis. We used blood infected with known concentrations of Trypanosoma copemani to test the impact of analysis techniques on trypanosome detection sensitivity by PCR. We compared combinations of a manual and an automated DNA extraction method and two different PCR primer sets to investigate the impact of each on detection levels. Both extraction techniques and specificity of primer sets had a significant impact on detection sensitivity. Samples extracted using the same DNA extraction technique performed substantially differently for each of the separate primer sets. Type I errors (false positives; detection of the target when it is not present), produced by contaminants, were avoided with both extraction methods. This study highlights the importance of testing laboratory techniques with known samples to optimise accuracy of test results. © 2014 Elsevier Inc.
Tapper S.-L.,Science and Conservation Division |
Byrne M.,Science and Conservation Division |
Yates C.J.,Science and Conservation Division |
Keppel G.,Curtin University Australia |
And 7 more authors.
Journal of Biogeography | Year: 2014
Aim: Granite outcrops may be able to act as refugia for species during adverse climate change, owing to their topographic complexity. We assessed this hypothesis by examining phylogeographical patterns in a common, geographically widespread granite endemic, Stypandra glauca (Hemerocallidaceae). Location: Granite outcrops of the Southwest Australian Floristic Region, Western Australia. Methods: Twenty-four tetraploid individuals of the granite endemic Stypandra glauca were sampled from each of 12 granite outcrops: 7 from a mesic environment and 5 from the semi-arid region. Phylogenetic reconstruction and divergence-dating was achieved using Bayesian and parsimony analyses of chloroplast haplotypes from 90 individuals. Nuclear diversity and population differentiation were analysed across all individuals using 10 microsatellite loci. Results: Stypandra glauca exhibited high (chloroplast) or moderate (nuclear) levels of divergence among, and low diversity within, outcrops. Haplotype diversity was high in both sampling regions, and each haplotype was unique to one outcrop. There was little correlation between geographical and genetic distance. Both nuclear and chloroplast diversity were higher in southern (mesic) outcrops than in northern (semi-arid) outcrops, although the level of chloroplast divergence among outcrops was similar for both climatic regions. Main conclusions: The levels of divergence and low diversity revealed in S. glauca support a scenario of prolonged isolation and persistence on granite outcrops in both mesic and semi-arid climatic regions, with no evidence of contraction-expansion dynamics across the outcrop network. The higher levels of diversity in the southern populations may result from the maintenance of a larger effective population size in southern regions, which retained more mesic climates during drier glacial periods. Although the climatic conditions differ between outcrops in this study, our results indicate that outcrops in both regions have harboured S. glauca throughout climatic changes, accentuating the value of these habitats to biodiversity conservation under future changing climate. © 2014 John Wiley & Sons Ltd.
Vitelli F.,Edith Cowan University |
Hyndes G.A.,Edith Cowan University |
Kendrick A.,Science and Conservation Division |
Turco A.,Edith Cowan University
Marine Ecology Progress Series | Year: 2015
Species belonging to the family Pomacentridae play a key role in altering algal assemblages in tropical systems, but our understanding about this family's role in temperate systems is limited. We examine the role of the abundant and territorial pomacentrid Parma mccullochi as an herbivore in temperate waters of southwestern Australia. Through dietary analyses, we showed that this species consumed predominantly red foliose and filamentous algae that were positively selected based on electivity indices. The species composition of macroalgae differed significantly between inside and outside P. mccullochi territories, with commonly ingested algae such as Hypnea spp. characterising the territory assemblages, while brown algae such as kelp Ecklonia radiata, and other foliose or coralline red algae characterised reef area outside the territories. Total algal biomass was significantly lower, while species richness was higher, inside compared to outside territories. In contrast, a caging experiment inside P. mccullochi territories showed that species composition, species richness and biomass of recruiting algae did not differ significantly in treatments where damselfishes were excluded or able to forage. A visual census indicated that P. mccullochi territories covered nearly 40% of the reef in the study region. We conclude that, while other biological or physical processes are likely to create the patches within kelp canopies where P. mccullochi territories are established, the species appears to have a strong and extensive influence in maintaining lower standing crop and higher diversity in turfforming algal assemblages in this temperate region. Understanding the role of herbivores in temperate regions is becoming increasingly important due to the effects of climate change through the shifting ranges of tropical species into temperate systems. © Inter-Research 2015.
Gibson N.,Science and Conservation Division |
Gibson N.,University of Western Australia
Nuytsia | Year: 2016
An analysis of the Western Australian Herbarium collections generated a list of 29 endemic taxa last collected between 1888 and 1965, which are not currently on the Presumed Extinct schedule. On review, four of these taxa are not of immediate concern. The remaining 25 taxa are predominantly shrubs, generally known from very few collections, and are concentrated in heavily cleared bioregions, particularly the Avon Wheatbelt. Two taxa, Ptilotus sericostachyus subsp. roseus (Moq.) Benl and Darwinia divisa Keighery & N.G.Marchant, are recommended for immediate nomination as Presumed Extinct, while the remaining taxa will require further survey and/or taxonomic work to resolve their conservation status. Further survey will be challenging given the general lack of specific geographical and habitat information available for these taxa. © Department of Parks and Wildlife 2016.
Dillon S.J.,Western Australian Herbarium |
Markey A.S.,Science and Conservation Division
Nuytsia | Year: 2016
A new species of Dysphania R.Br., D. congestiflora S.J.Dillon & A.S.Markey is described and an amendment to the most recent key of Dysphania is provided to include the new taxon. © Department of Parks and Wildlife 2016.
Nistelberger H.,Science and Conservation Division |
Gibson N.,Science and Conservation Division |
Macdonald B.,Science and Conservation Division |
Tapper S.-L.,Science and Conservation Division |
Byrne M.,Science and Conservation Division
Heredity | Year: 2014
Phylogeographic studies of flora in species-rich south-western Australia point to complex evolutionary histories, reflecting patterns of persistence and resilience to climatic changes during the Pleistocene. We asked whether coastal areas of the mid-west and south, as well as granite outcrops and inland ranges, have acted as major refugia within this region during Pleistocene climatic fluctuations by analysing phylogeographic patterns in the shrub Calothamnus quadrifidus R.Br. (Myrtaceae). We determined variation in chloroplast DNA data for 41 populations across the geographic range. Relationships and major clades were resolved using parsimony and Bayesian analyses. We tested for demographic and spatial expansion of the major clades and estimated clade divergence dates using an uncorrelated, lognormal relaxed clock based on two conservative chloroplast mutation rates. Two distinct phylogeographic clades were identified showing divergence during the Pleistocene, consistent with other phylogeographic studies of south-west Australian flora, emphasising the impact of climatic oscillations in driving divergence in this landscape. The southern clade was more diverse, having higher haplotype diversity and greater genetic structure, while the northern clade showed evidence of fluctuation in population size. Regions of high haplotype diversity with adjacent areas of low diversity observed in each clade indicated the locations of two coastal refugia: one on the south coast and another along the mid-west coast. This is the first evidence for major Pleistocene refugia using chloroplast genetic data in a common, widespread species from this region.
Gosper C.R.,Science and Conservation Division |
Gosper C.R.,CSIRO |
Prober S.M.,CSIRO |
Yates C.J.,Science and Conservation Division
Journal of Biogeography | Year: 2016
Global and continental-scale analysis of ecological phenomena can offer important insights through the identification of patterns and associations not detectable at smaller scales. However, using proxies for ecological phenomena, such as vegetation mapping for spatially projecting fire regime niches and post-fire plant responses, require critical examination of predictions to determine utility. Using local studies in south-western Australia, we demonstrate that while this approach has been largely successful in mallee woodland and shrubland, it has failed in eucalypt woodland, with the consequence that values for a range of fire-related parameters from the continent-wide approaches, if adopted in informing management, would result in undesirable conservation outcomes for the world's largest extant temperate woodland. © 2016 John Wiley & Sons Ltd.