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Dr Brad Murray

Biography

Brad Murray has research and teaching interests in ecology, evolution and biodiversity conservation. His work explores how species abundance, distribution and diversity vary across space and through time in relation to life history, phylogeny and environmental changes brought about by human activities. A complete list of Brad's scientific publications can be found at PublicationsList. He is currently an Associate Editor with the journal NeoBiota which has a focus on biological invasions.

Image of Brad Murray
Senior Lecturer, School of the Environment
BSc (Hons) (Syd), PhD (Macquarie)
 
Phone
+61 2 9514 4075
Room
CB04.05.62C

Research Interests

Brad's ecology and conservation lab works primarily with terrestrial plants, at times exploring interactions between plants and fauna. The lab's research involves field work, laboratory and glasshouse experiments, as well as the desktop compilation and analysis of ecological datasets. The lab has specialist expertise in experimental design and statistical analysis.

Current research is centred on plant reproductive ecology, fire ecology, invasion ecology and macroecology. Information on past research projects can be gleaned from the list of previous student projects below (and Brad’s PublicationsList), with projects in discipline areas including urban ecology, wildlife ecology, ecosystem valuation, ecotoxicology, the ecology of groundwater-dependent ecosystems, restoration ecology, the comparative ecology of rarity and the dietary ecology of desert rodents.

Current members of the lab:

Dr Megan Phillips (Research Comrade)

Dr Leigh Martin (Research Associate)

Mr Matt Hingee (PhD Student)

Mr Dan Krix (Honours Student)

Ms Madeline Ross (Honours Student)

Previous members of the lab:

2013 Rebecca Lay (Honours) The Ecology of the Noisy Miner in an Urban Environment.

2012 Emily Strautins (Honours) Habitat selection by frogs in a peri-urban environment: do frogs avoid weeds?  

2012 Ellen Mannix (Honours) Comparative patterns of habitat use by bird assemblages in an urban environment.
 
2012 Megan Phillips (PhD) Plant life history and the naturalisation to invasion transition: the exotic flora of Australia.
 
2012 Leigh Martin (PhD) Impacts of invasive exotic plants on reptile and amphibian assemblages.
 
2012 Tara Konarzewski (PhD) Clinal variation in life-history traits of the invasive plant species Echium plantagineum L.

2010 Kien Nguyen (Honours) Impacts of invasive African olive on leaf-litter invertebrate assemblages.
 
2010 Lyndle Hardstaff (Honours) Relationships between leaf flammability and leaf traits in native and exotic species of dry sclerophyll forest.

2009 Damian Licari (PhD) Long-term changes in grassland, woodland and forest vegetation of south-eastern Australia: impacts of land-use change.

2008 Tara Vaughan (Honours) Relating interspecific variation in seed mass to seedling growth under climate change.
 
2008 Carla Harris (PhD) Invasion success of exotic vines in Australia: the importance of life-history, introduction-history and ecological attributes.
 
2008 Andrew Baker (PhD) The dynamics of litterfall in eucalypt woodland surrounding pine plantations.

2007 Tessa Robson (Honours) The effects of Pine (Pinus radiata D. Don) plantations on leaf-litter invertebrates.

2006 Noni Dowsett (Honours) Distribution and abundance of mammals in vegetation invaded by Lantana camara.
 
2006 Andrew Cantlay (Honours) Bird communities within heath and woodland vegetation invaded by Lantana camara.

2004 Andrew Baker (Honours) Ecosystem responses to Pinus radiata invasion.

2003 Mark Hamilton (Honours) The abundance, distribution and life history of exotic plant species in Royal National Park.

Can supervise: Yes

Current Teaching

Subject Coordinator, 91154 Ecology (second-year subject)

Subject Coordinator, 91309 Biodiversity Conservation (third-year subject)

Principal supervisor of Honours students in Environmental Sciences

Book Chapters

Stohlgren, T., Pysek, P., Kartesz, J., Nishino, M., Pauchard, A., Winter, M., Pino, J., Richardson, D.M., Wilson, J., Murray, B.R., Phillips, M., Celesti-Grapow, L. & Graham, J. 2013, 'Globalization Effects on Common Plant Species' in Simon Levin (ed), Encyclopedia of Biodiversity, Elsevier Inc., Waltham, MA, USA, pp. 700-706.
The trade of goods by humans has bridged the continents, in effect restoring the old supercontinent of Pangaea. In the past century, humans have been responsible for an exponential increase in plant migrations, moving plant species around the globe for food, fuel, forage, horticulture, landscaping, and medicines. Trade within and among continents is breaking geographic barriers and providing long-range dispersal for seeds and propagules at unprecedented rates (Richardson et al., 2000; Wilson et al., 2009). Here, the authors provide a brief review of the globalization effects on common plant species and ++++homogenization++++ of the world++s plant communities.
Booth, D.J. & Murray, B.R. 2008, 'Coexistence' in S.E. Jrgensen and B.D. Fath (eds), Encyclopedia of Ecology, Five-Volume Set, Elsevier, Amsterdam, pp. 664-668.
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Murray, B.R., Dickman, C.R., Robson, T.C., Haythornthwaite, A., Cantlay, A.J., Dowsett, N.S. & Hills, N. 2007, 'Effects of exotic plants in native vegetation on species richness and abundance of birds.' in Lunney, D (eds), Pest or guest : the zoology of overabundance, Royal Zoological Society of New South Wales, Mosman, N.S.W, pp. 216-221.
We reviewed published, quantitative studies examining the effects of exotic plants in native vegetation on the species richness and abundance of birds and mammals. We asked whether the incursion of exotic plants into native vegetation has led to consistent declines, increases or no changes in bird and mammal species richness and abundance. Bird species richness and abundance tended not to be lower in sites with exotic plants (exotic sites) compared with sites without exotic plants (native sites). However, there are some reported cases of declines in richness, and declines and increases in abundance of birds in exotic sites. While there is not enough evidence to generate broad patterns in relation to species richness of mammals in exotic sites, abundances of individual mammal species demonstrated idiosyncratic responses (either increases, decreases, or no changes) to the incursion of exotic plants. Any differences observed in species richness and abundance of birds and mammals between exotic and native sites are probably due to habitat modifications by exotic plants resulting in changes to vegetation that is important for foraging, protection, and reproduction of the vertebrates. Importantly, our review found no published, quantitative evidence that the incursion of exotic plants into native vegetation leads to the over-abundance of any bird or mammal species. Nevertheless, the results of our review must be viewed as preliminary findings: there is still much to be done to untangle the complex ecological effects of exotic plants on birds and mammals in native vegetation.
Dickman, C.R. & Murray, B.R. 2006, 'Species interactions: complex effects' in Attiwell, P; Wilson, B. (eds), Ecology: An Australian Perspective, Oxford University Press, South Melbourne, Australia, pp. 317-334.
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Interactions within ecological communities usually involve many species and pose intriguing challenges for ecologists who wish to map and disentangle them. To simplify this task we often assume that the interactions do not change in strength or direction and that the identities of the key species remain the same. Species can be 'pigeon-holed' into convenient categories such as 'pollinator', 'competitor', 'pest' or even 'redundant' using these assumptions. This makes programs of conservation or pest management easier to implement, but is also ignores an emerging body of evidence that interactions between species vary between situations, places and times. In this chapter we will explore the complexity of effects that arise from changes in tereactions between species. We also consider how such effects may be modelled and predicted,a nd illustrate how ecological insight can be used to guide management decisions.
Thrall, P.H., Burdon, J.J. & Murray, B.R. 2000, 'The metapopulation paradigm: a fragmented view of conservation biology' in Young A.G., Clarke G.M. (eds), Genetics, Demography and Viaability of Fragmented Populations, Cambridge University Press, Cambridge,United Kingdom, pp. 75-95.
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In the past, single-population approaches have dominated ecology and evolutionary biology. However, populations are not isolated either in time or space, but are connected by among-population processes such as migration and gene flow.While this concept is not new, until recently, there have beenrelatively few studies that have explicitly investigated the effects od spatial structure on demographic and genetic processes in the context of conservation. The metapopulation framework explicitly recognises and provides a conceptual tool for dealing with the interactions of within - (e.g. birth, death, competition) and among-population processes (e.g. dispersal, gene flow, colonisation and extinction). The ever-growing diversity of empirical and theoretical studies that demonstrate the importance of spatial structure in determining ecological and evolutionary trajectories also indicates that long-term conservation programmes need to focus on regional rather than local within-population persistence. In this regard, it is important to realise that ultimately all populations are ephemeral, and therefore colonisation processes must also be preserved. Clearly, not all species whose populations have undergone fragmentation fit the definition of a metapopulation. Nevertheless, a metapopulation approach to conservation biology is likely to provide a useful tool for developing management strategies as it addresses genetic, species and community effects of fragmentation in a single framework, therby making explicit questions regarding extinction, population connectedness, species behavioural patterns and the survival of coevolved systems. In essence, a metapopulation perspective ensures a process oriented, scale-appropriate approach to conservation that focuses attention on among-population processes critical for persistence of many natural systems.

Conference Papers

Yunusa, I.A., Eamus, D., De Silva, D.L., Murray, B.R., Burchett, M., Skilbeck, C.G. & Heidrich, C. 2005, 'Prospects for coal-ash in the management of Australian soils', World of Coal Ash 2005, Lexington, USA, April 2005 in World of Coal Ash Proceedings, ed Caylor, G, Coal ash Association and the University of Kentucky's Centre for Applied Energy Research, Lexington, USA, p. CD ROM.

Journal Articles

Gribben, P.E., I'Ons, S., Phillips, N.E., Geange, S.W., Wright, J.T. & Murray, B.R. 2013, 'Biogeographic comparisons of the traits and abundance of an invasive crab throughout its native and invasive ranges', Biological Invasions, vol. 15, no. 8, pp. 1877-1885.
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High abundances of non-native species in the invaded range may be linked to changes in fitness related traits. However, few studies have compared differences in both life-history traits and abundances of introduced species between their native and invaded ranges. We determined differences in 12 morphological traits, an important fitness related trait (body size), and the abundance of the porcelain crab, Petrolisthes elongatus, in its native (New Zealand) and invasive (Tasmania, Australia) ranges. P. elongatus was more abundant in the introduced range; however, changes in abundance depended on tidal height, with higher abundances only at mid and low tidal zones. The biomass of male crabs was higher in the invaded range compared to the native range, but there was no difference in female biomass between ranges. Despite increases in male biomass, sex ratios between native and invasive populations did not differ. In addition, principal components analysis showed no differences in overall morphology between Tasmania and New Zealand. Our study indicates that increased abundance in the invaded range of P. elongatus may be linked to high values of an important trait (greater biomass) in the invaded range. Importantly, changes in biomass and abundance may be due to P. elongatus being able to utilise mid/low zones more in the invaded range. Furthermore, our findings indicate that understanding how sex specific changes in biomass interact with the recipient environment (biotic and abiotic) in the introduced range will be important for determining the mechanisms underpinning the establishment and spread of P. elongatus.
Martin, L.J. & Murray, B.R. 2013, 'A preliminary assessment of the response of a native reptile assemblage to spot-spraying invasive Bitou Bush with glyphosate herbicide', Ecological Management & Restoration, vol. 14, no. 1, pp. 59-62.
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During recent work examining the effects of Bitou Bush (Chrysanthemoides monilifera ssp.rotundata) invasion on native reptile assemblages in coastal heathland vegetation in Eastern Australia, unplanned spot-spraying of glyphosate occurred at some of our
Murray, B.R., Hardstaff, L.K. & Phillips, M. 2013, 'Differences in Leaf Flammability Leaf Traits and Flammability-Trait Relationships between Native and Exotic Plant Species of Dry Sclerophyll Forest', PLoS One, vol. 8, no. 11, pp. e79205-1-e79205-8.
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The flammability of plant leaves influences the spread of fire through vegetation. Exotic plants invading native vegetation may increase the spread of bushfires if their leaves are more flammable than native leaves. We compared fresh-leaf and dryleaf flammability (time to ignition) between 52 native and 27 exotic plant species inhabiting dry sclerophyll forest. We found that mean time to ignition was significantly faster in dry exotic leaves than in dry native leaves. There was no significant native-exotic difference in mean time to ignition for fresh leaves. The significantly higher fresh-leaf water content that was found in exotics, lost in the conversion from a fresh to dry state, suggests that leaf water provides an important buffering effect that leads to equivalent mean time to ignition in fresh exotic and native leaves. Exotic leaves were also significantly wider, longer and broader in area with significantly higher specific leaf area+but not thicker+than native leaves. We examined scaling relationships between leaf flammability and leaf size (leaf width, length, area, specific leaf area and thickness). While exotics occupied the comparatively larger and more flammable end of the leaf size-flammability spectrum in general, leaf flammability was significantly correlated with all measures of leaf size except leaf thickness in both native and exotic species such that larger leaves were faster to ignite. Our findings for increased flammability linked with larger leaf size in exotics demonstrate that exotic plant species have the potential to increase the spread of bushfires in dry sclerophyll forest.
Baker, A.C. & Murray, B.R. 2012, 'Seasonal intrusion of litterfall from non-native pine plantations into surrounding native woodland: implications for management of an invasive plantation species', Forest Ecology and Management, vol. 277, pp. 25-37.
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Radiata pine (Pinus radiata) is commonly grown throughout the world as a major plantation species. Non-native radiata pine plantations are often established as monocultures amongst large tracts of remnant native vegetation. While the direct impacts on native biodiversity of such vegetation replacement have been well documented, much less is known about how plant litterfall from such plantations influences ecosystem dynamics beyond the confines of the plantation limits. In this study, we assessed the inputs of plant litterfall from radiata pine plantations into surrounding native woodland vegetation over a two-year period in south-eastern Australia. We found that pine litter was a significant and even dominant component of litterfall at certain times of the year, typically autumn and winter, when quantities of pine needles falling were up to three times the fall of native leaves. Pine litter was found to be lower in quality than native litter, containing less carbon (C) and nitrogen (N) and having a higher C:N ratio than native litter. Although the comparatively larger inputs of pine litter resulted in C and N inputs that were 2-3 times those of native litter during some seasons, the influx of low-quality pine litter is likely to decompose slowly and immobilise N, thereby limiting the availability of N for plant growth in the long term. The intrusion of large quantities of pine litter into native eucalypt woodland may have a suite of further short and long term impacts on native biodiversity through a number of mechanisms including alteration of leaf-litter invertebrate communities, increased fire intensity and changes in microclimate. These impacts may be alleviated by preventing pine litter entering woodland communities through the use of modified buffer zones and by employing appropriate plantation design. We discuss the merits and shortfalls of various options available to land mangers to minimise pine-litter intrusion into adjacent native woodlands.
Murray, B.R. & Phillips, M.L. 2012, 'Temporal introduction patterns of invasive alien plant species to Australia', NeoBiota, vol. 13, pp. 1-14.
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We examined temporal introduction patterns of 132 invasive alien plant species (IAPS) to Australia since European colonisation in 1770. Introductions of IAPS were high during 1810+1820 (10 species), 1840+ 1880 (51 species, 38 of these between 1840 and 1860) and 1930+1940 (9 species). Conspicuously few introductions occurred during 10-year periods directly preceding each introduction peak. Peaks during early European settlement (1810+1820) and human range expansion across the continent (1840-1860) both coincided with considerable growth in Australia+s human population. We suggest that population growth during these times increased the likelihood of introduced plant species becoming invasive as a result of increased colonization and propagule pressure. Deliberate introductions of IAPS (104 species) far outnumbered accidental introductions (28 species) and were particularly prominent during early settlement. Cosmopolitan IAPS (25 species) and those native solely to South America (53 species), Africa (27 species) and Asia (19 species) have been introduced deliberately and accidentally to Australia across a broad period of time. A small number of IAPS, native solely to Europe (5 species) and North America (2 species), were all introduced to Australia prior to 1880. These contrasting findings for native range suggest some role for habitat matching, with similar environmental conditions in Australia potentially driving the proliferation of IAPS native to southern-hemisphere regions.
Lloyd, H.B., Murray, B.R. & Gribben, P.E. 2012, 'Trait and abundance patterns in two marine molluscs: the influence of abiotic conditions operating across multiple spatial scales', Marine Ecology Progress Series, vol. 463, pp. 205-214.
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Theoretical mechanisms describing species abundance distributions should also underpin geographic variation in life-history traits. However, recent studies suggest that abundance and trait patterns may not co-vary and may respond differently to abiotic conditions acting at different spatial scales. We examined patterns in abundance and body size of 2 estuarine molluscs, the arkshell Anadara trapezia and the mudsnail Batillaria australis, across their wide distributions in eastern Australia. We related abundance and body size patterns to abiotic variables including water temperature, pH, salinity, sediment redox and dissolved oxygen content at multiple spatial scales. Two hypotheses were tested: (1) geographic patterns in abundance and body size do not co-vary, and (2) patterns in abundance are more strongly influenced by abiotic conditions occurring at a large spatial scale (e.g. across latitudinal gradients) whereas body size is more strongly influenced by variation in abiotic conditions occurring at smaller scales. The influence of spatial scale and associated abiotic variables on abundance and body size distributions was determined using multiple linear regression, ANOVA and variance component analyses. Geographic variation in abundance and body size were independent of each other in both species. Abiotic variation across latitudinal gradients was the strongest predictor of abundance, but factors that varied substantially at local scales (e.g. dissolved oxygen and sediment redox) were the strongest predictors of body size. Our data indicate that geographic patterns in body size and abundance can be disconnected from each other, most likely due to differential responses to abiotic variation acting at different spatial scales.
Phillips, M. & Murray, B.R. 2012, 'Invasiveness in exotic plant species is linked to high seed survival in the soil', Evolutionary Ecology Research, vol. 14, no. 1, pp. 83-94.
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Background: Exotic species often do no harm for many generations and then become invasive. The science of invasion ecology seeks to determine the nature or causes of this change. Among the possibilities is that soil-borne fungi play a significant role in reducing the potential for invasiveness in the introduced range. Predictions: The seed survival of invasive species in the soil exceeds that of non-invasives. Seed survival, both in invasives and non-invasives, is higher in the presence of fungicide, but fungicide improves the seed survival of non-invasives more than that of invasives. Methods: A common garden experiment under field conditions to compare seed survival in the soil between invasive and non-invasive exotic plant species. We contrasted seven congeneric pairs of invasive and non-invasive species. The species in each pair originated from the same donor continent, shared similar growth form, habitat occurrence, and residence times in Australia. The addition of fungicide was used as an experimental treatment. Results: Seed survival was significantly higher in invasive species. The addition of fungicide improved seed survival. However, there was also a significant interaction: the fungicide treatment had a significantly stronger effect on the seed survival of non-invasive species. Seed mass differences between congeners did not provide a consistent, significant explanation of seed survival differences. Conclusion: The seeds of invasive species are better equipped to survive in the soil than those of non-invasive species. Moreover, soil-borne fungi play a key role in the lower seed survival of non-invasive species.
Murray, B.R. 2012, 'Fifty Years of Invasion Ecology: The Legacy of Charles Elton', Austral Ecology, vol. 37, pp. e43-e43.
Konarzewski, T.K., Murray, B.R. & Godfree, R.C. 2012, 'Rapid development of adaptive, climate-driven clinal variation in seed mass in the invasive annual forb Echium plantagineum L.', PLoS One, vol. 7, no. 12, pp. 1-10.
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We examined adaptive clinal variation in seed mass among populations of an invasive annual species, Echium plantagineum, in response to climatic selection. We collected seeds from 34 field populations from a 1,000 km long temperature and rainfall gradient across the species++ introduced range in south-eastern Australia. Seeds were germinated, grown to reproductive age under common glasshouse conditions, and progeny seeds were harvested and weighed. Analyses showed that seed mass was significantly related to climatic factors, with populations sourced from hotter, more arid sites producing heavier seeds than populations from cooler and wetter sites. Seed mass was not related to edaphic factors. We also found that seed mass was significantly related to both longitude and latitude with each degree of longitude west and latitude north increasing seed mass by around 2.5% and 4% on average. There was little evidence that within-population or between-population variation in seed mass varied in a systematic manner across the study region. Our findings provide compelling evidence for development of a strong cline in seed mass across the geographic range of a widespread and highly successful invasive annual forb. Since large seed mass is known to provide reproductive assurance for plants in arid environments, our results support the hypothesis that the fitness and range potential of invasive species can increase as a result of genetic divergence of populations along broad climatic gradients. In E. plantagineum population-level differentiation has occurred in 150 years or less, indicating that the adaptation process can be rapid.
Martin, L.J. & Murray, B.R. 2011, 'A predictive framework and review of the ecological impacts of exotic plant invasions on reptiles and amphibians', Biological Reviews, vol. 86, no. 2, pp. 407-419.
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The invasive spread of exotic plants in native vegetation can pose serious threats to native faunal assemblages. This is of particular concern for reptiles and amphibians because they form a significant component of the world++s vertebrate fauna, play a pivotal role in ecosystem functioning and are often neglected in biodiversity research. A framework to predict how exotic plant invasion will affect reptile and amphibian assemblages is imperative for conservation, management and the identification of research priorities. Here, we present a new predictive framework that integrates three mechanistic models. These models are based on exotic plant invasion altering: (1) habitat structure; (2) herbivory and predator-prey interactions; (3) the reproductive success of reptile and amphibian species and assemblages. We present a series of testable predictions from these models that arise from the interplay over time among three exotic plant traits (growth form, area of coverage, taxonomic distinctiveness) and six traits of reptiles and amphibians (body size, lifespan, home range size, habitat specialisation, diet, reproductive strategy). A literature review provided robust empirical evidence of exotic plant impacts on reptiles and amphibians from each of the three model mechanisms. Evidence relating to the role of body size and diet was less clear-cut, indicating the need for further research. The literature provided limited empirical support for many of the other model predictions. This was not, however, because findings contradicted our model predictions but because research in this area is sparse. In particular, the small number of studies specifically examining the effects of exotic plants on amphibians highlights the pressing need for quantitative research in this area. There is enormous scope for detailed empirical investigation of interactions between exotic plants and reptile and amphibian species and assemblages.
Simberloff, D., Alexander, J., Allendorf, F., Aronson, J., Antunes, P.M., Bacher, S., Bardgett, R., Bertolino, S., Bishop, M.J., Blackburn, T.M., Blakeslee, A., Blumenthal, D., Bortolus, A., Buckley, R., Buckley, Y., Byers, J., Callaway, R.M., Campbell, F., Campbell, K., Campbell, M., Carlton, J.T., Cassey, P., Catford, J., Celesti-Grapow, L., Chapman, J.C., Clark, P., Clewell, A., Canning Clode, J., Chang, A., Chytry, M., Clout, M., Cohen, A., Cowan, P., Cowie, R.H., Crall, A.W., Crooks, J., Deveney, M., Dixon, K., Dobbs, F.C., Cameron Duffy, D., Duncan, R., Ehrlich, P., Eldredge, L., Evenhuis, N., Fausch, K.D., Feldhaar, H., Firn, J., Fowler, A., Galil, B., Garcia-Berthou, E., Geller, J., Genovesi, P., Gerber, E., Gherardi, F., Gollasch, S., Gordon, D., Graham, J., Gribben, P.E., Griffen, B., Grosholz, E.D., Hewitt, C., Hierro, J.L., Hulme, P., Hutchings, P., Jarosik, V., Johnson, C., Johnson, L., Johnston, E.L., Jones, C.G., Keller, R., King, C.M., Knols, B.G., Kollmann, J., Kompas, T., Kotanen, P.M., Kowarik, I., K++hn, I., Kumschick, S., Leung, B., Liebhold, A., MacIsaac, H., Mack, R., McCullough, D.G., McDonald, R., Merritt, D.M., Meyerson, L., Minchin, D., Mooney, H.A., Morisette, J.T., Moyle, P., M++ller-Sch+rer, H., Murray, B.R., Nehring, S., Nelson, W., Nentwig, W., Novak, S.J., Occhipinti, A., Ojaveer, H., Osborne, B., Ostfeld, R.S., Parker, J., Pederson, J., Pergl, J., Phillips, M., Pysek, P., Rejmanek, M., Ricciardi, A., Ricotta, C., Richardson, D.M., Rilov, G., Ritchie, E., Robertson, P.A., Roman, J., Ruiz, G.M., Schaefer, H., Schaffelke, B., Schierenbeck, K.A., Schmitz, D.C., Schwindt, E., Seeb, J., David Smith, L., Smith, G.F., Stohlgren, T., Strayer, D.L., Strong, D., Sutherland, W.J., Therriault, T., Thuiller, W., Torchin, M., van der Putten, W., Vila, M., Von Holle, B., Wallentinus, I., Wardle, D., Williamson, M., Wilson, J., Winter, M., Wolfe, L.M., Wright, J., Wonham, M. & Zabin, C. 2011, 'Non-natives: 141 scientists object', Nature, vol. 475, pp. 36-36.
Stohlgren, T., Pysek, P., Kartesz, J., Nishino, M., Pauchard, A., Winter, M., Pino, J., Richardson, D.M., Wilson, J.R., Murray, B.R., Phillips, M., Ming-yang, L., Celesti-Grapow, L. & Font, X. 2011, 'Widespread plant species: natives versus aliens in our changing world', Biological Invasions, vol. 13, pp. 1931-1944.
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Estimates of the level of invasion for a region are traditionally based on relative numbers of native and alien species. However, alien species differ dramatically in the size of their invasive ranges. Here we present the first study to quantify the level of invasion for several regions of the world in terms of the most widely distributed plant species (natives vs. aliens). Aliens accounted for 51.3% of the 120 most widely distributed plant species in North America, 43.3% in New South Wales (Australia), 34.2% in Chile, 29.7% in Argentina, and 22.5% in the Republic of South Africa. However, Europe had only 1% of alien species among the most widespread species of the flora. Across regions, alien species relative to native species were either as well-distributed (10 comparisons) or more widely distributed (5 comparisons). These striking patterns highlight the profound contribution that widespread invasive alien plants make to floristic dominance patterns across different regions. Many of the most widespread species are alien plants, and, in particular, Europe and Asia appear as major contributors to the homogenization of the floras in the Americas. We recommend that spatial extent of invasion should be explicitly incorporated in assessments of invasibility, globalization, and risk assessments.
Kuhn, I., Kowarik, I., Kollmann, J., Starfinger, U., Bacher, S., Blackburn, T.M., Bustamante, R.O., Celesti-Grapow, L., Chytry, M., Colautti, R.I., Essl, F., Foxcroft, L.C., Garcia-Berthou, E., Gollasch, S., Hierro, J.L., Hufbauer, R.A., Hulme, P., Jarosik, V., Jeschke, J.M., Karrer, G., Mack, R., Molofsky, J., Murray, B.R., Nentwig, W., Osborne, B., Pysek, P., Rabitsch, W., Rejmanek, M., Roques, A., Shaw, R., Sol, D., Van Kleunen, M., Vila, M., von der Lippe, M., Wolfe, L.M. & Penev, L. 2011, 'Open minded and open access: introducing NeoBiota, a new peer-reviewed journal of biological invasions', NeoBiota, vol. 9, pp. 1-11.
The Editorial presents the focus, scope, policies, and the inaugural issue of NeoBiota, a new open access peer-reviewed journal of biological invasions. The new journal NeoBiota is a continuation of the former NEOBIOTA publication series. The journal will deal with all aspects of invasion biology and impose no restrictions on manuscript size neither on use of color. NeoBiota implies an XML-based editorial workflow and several cutting-edge innovations in publishing and dissemination, such as semantic markup of and enhancements to published texts, data publication, and extensive cross-linking within the journal and to external sources.
Simberloff, D., Alexander, J., Allendorf, F., Aronson, J., Antunes, P.M., Bacher, S., Bardgett, R., Bertolino, S., Bishop, M.J., Blackburn, T.M., Blakeslee, A., Blumenthal, D., Bortolus, A., Buckley, R., Buckley, Y., Byers, J., Callaway, R.M., Campbell, F., Campbell, K., Campbell, M., Carlton, J.T., Cassey, P., Catford, J., Celesti-Grapow, L., Chapman, J.C., Clark, P., Clewell, A., Canning Clode, J., Chang, A., Chytry, M., Clout, M., Cohen, A., Cowan, P., Cowie, R.H., Crall, A.W., Crooks, J., Deveney, M., Dixon, K., Dobbs, F.C., Cameron Duffy, D., Duncan, R., Ehrlich, P., Eldredge, L., Evenhuis, N., Fausch, K.D., Feldhaar, H., Firn, J., Fowler, A., Galil, B., Garcia-Berthou, E., Geller, J., Genovesi, P., Gerber, E., Gherardi, F., Gollasch, S., Gordon, D., Graham, J., Gribben, P.E., Griffen, B., Grosholz, E.D., Hewitt, C., Hierro, J.L., Hulme, P., Hutchings, P., Jarosik, V., Johnson, C., Johnson, L., Johnston, E.L., Jones, C.G., Keller, R., King, C.M., Knols, B.G., Kollmann, J., Kompas, T., Kotanen, P.M., Kowarik, I., K++hn, I., Kumschick, S., Leung, B., Liebhold, A., MacIsaac, H., Mack, R., McCullough, D.G., McDonald, R., Merritt, D.M., Meyerson, L., Minchin, D., Mooney, H.A., Morisette, J.T., Moyle, P., M++ller-Sch+rer, H., Murray, B.R., Nehring, S., Nelson, W., Nentwig, W., Novak, S.J., Occhipinti, A., Ojaveer, H., Osborne, B., Ostfeld, R.S., Parker, J., Pederson, J., Pergl, J., Phillips, M., Pysek, P., Rejmanek, M., Ricciardi, A., Ricotta, C., Richardson, D.M., Rilov, G., Ritchie, E., Robertson, P.A., Roman, J., Ruiz, G.M., Schaefer, H., Schaffelke, B., Schierenbeck, K.A., Schmitz, D.C., Schwindt, E., Seeb, J., David Smith, L., Smith, G.F., Stohlgren, T., Strayer, D.L., Strong, D., Sutherland, W.J., Therriault, T., Thuiller, W., Torchin, M., van der Putten, W., Vila, M., Von Holle, B., Wallentinus, I., Wardle, D., Williamson, M., Wilson, J., Winter, M., Wolfe, L.M., Wright, J., Wonham, M. & Zabin, C. 2011, 'Non-natives: 141 scientists object', Nature, vol. 475, no. 7354, pp. 1-2.
We the undersigned feel that in advocating a change in the environmental management of introduced species (Nature 474, 153+154; 2011), Mark Davis and colleagues assail two straw men.
Martin, L.J. & Murray, B.R. 2011, 'A comparison of short-term marking methods for small frogs using a model species, the striped marsh frog (Limnodynastes peronii)', Herpetological Journal, vol. 21, no. 4, pp. 271-273.
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We compared three methods of marking individual small frogs for identification in short-term studies (several days) using a model species, Limnodynastes peronii (the striped marsh frog). We performed a manipulative experiment under laboratory conditions to compare retention times of gentian violet, mercurochrome and powdered fluorescent pigment. Gentian violet produced the most durable marks with retention times between two and four days. Mercurochrome was retained for at least one day by all treated frogs. Fluorescent pigment was either not retained at all or for one day at most, which suggests that this marking method may not be reliable for short-term studies where identification is required. No adverse reactions to any of the marking methods were detected in our study. Our findings indicate that gentian violet represents a promising alternative as a minimally invasive marking technique for studies of small frogs requiring only shortterm retention of identification marks.
Murray, B.R. & Phillips, M. 2010, 'Investment in seed dispersal structures is linked to invasiveness in exotic plant species of south-eastern Australia', Biological Invasions, vol. 12, no. 7, pp. 2265-2275.
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Naturalized plant species disperse their populations over considerable distances to become invasive. We tested the hypothesis that this shift from naturalization to invasion is facilitated by increased investment of resources in seed dispersal appendages, using an assemblage of naturalized plants of southeastern Australia. Compared with non-invasive species, we found in both cross-species and independent- contrasts analyses that invasive species invested more heavily in seed dispersal appendages, regardless of the structure present on the seed associated with the mode of dispersal (e.g., wings versus fleshy fruits). Invasive species such as Lonicera japonica, Hedera Helix and Acetosa sagittata were found to invest as much as 60 - 70% of total diaspore mass in dispersal appendages. The positive relationship between dispersal investment and invasion success was still prevalent after controlling for the effects of plant growth form, seed mass and capacity for vegetative growth. Our findings demonstrate that a plant's investment in dispersal appendages helps to overcome the dispersal barrier in the shift from naturalization to invasion.
Veeragathipillai, M., Yunusa, I.A., Loganathan, P., Lawrie, R., Skilbeck, C.G., Burchett, M., Murray, B.R. & Eamus, D. 2010, 'Assessments of Class F fly ashes for amelioration of soil acidity and their influence on growth and uptake of Mo and Se by canola', Fuel, vol. 89, no. 11, pp. 3498-3504.
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Coal fly ash can be used to ameliorate productivity constraints in agricultural soils, but their efficacy still remains highly variable. To ascertain the capacity of Class F fly ashes to modify pH of acidic soils, and their effects on the yield and uptake of molybdenum (Mo) and selenium (Se) by canola (Brassica napus L.), we applied two acidic and two alkaline Class F ashes at rates equivalent to 0, 12, 36, and 108 Mg/ ha to the top layer (0++10 cm) of 100 cm long intact cores of acidic sandy clay and clay loam soils. Only the alkaline ash which had the highest calcium carbonate equivalent (2.43%) increased the pH of the top 10 cm of the sandy clay soil. However, this ash was also highly saline and when applied at P36 Mg/ha it increased the electrical conductivity in the top soil layer. Increases in soil pH as a result of alkaline ash addition also elevated concentrations of Se in the plant shoot. The ashes with high concentrations of Mo and Se generally increased uptake of these elements in the plant shoot and/or seed. When these ashes were applied at 108 Mg/ha they increased the concentrations of these elements in the treated topsoil.
Veeragathipillai, M., Yunusa, I.A., Loganathan, P., Lawrie, R., Murray, B.R., Skilbeck, C.G. & Eamus, D. 2010, 'Boron contents and solubility in Australian fly ashes and its uptake by canola (Brassica napus L.) from the ash-amended soils', Australian Journal of Soil Research, vol. 48, no. 5, pp. 480-487.
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Phytotoxicity due to excessive boron (B) uptake by plants impedes routine agronomic utilisation of coal fly ash. We assessed 11 fly ashes (pH 3.14++10.77) having total B content (Bt) of 12++136 mg/kg, of which 20++30% was hot water soluble (Bs) in the acidic ashes (pH <5) and 5++10% in the alkaline ashes, for their potential to supply B to plants and their risk associated with phytotoxicity. We found the Bs/Bt to be negatively correlated (R2 = 0.63**, N = 11) with ash pH. We conducted two trials in which canola was grown in soils amended with fly ash. In the first trial, an alkaline fly ash (Bt 66 mg/kg) was incorporated at 5 rates of up to 625 Mg/ha into the top 50mm of 2 acidic soils in 0.30-m-long intact cores, and sown with canola. Boron concentration in leaves at flowering reached the phytotoxic threshold, and both plant growth and seed yield were reduced, only at 625 Mg/ha. In the second trial, 4 fly ashes (pH 3.29++10.77, Bt 12++127 mg/kg) were incorporated at 4 rates of up to 108 Mg/ha into the top 0.10mof 2 acidic soils in 1.0-m-long intact cores and then sown with canola. Ashes with highest Bt, when applied at 108 Mg/ha, increased B concentration in the topsoil only. Of the 2 ashes with the highest Bt, only that which produced low soil pH and applied at 108 Mg/ha increased B concentration in the shoot, but was still below phytotoxic threshold. The results suggest that B derived from these ashes may not cause phytotoxicity and excessive soil B accumulation if the ashes are applied at modest rates (<36 Mg/ha) to the topsoil layers.
Phillips, M.L., Murray, B.R., Leishman, M.R. & Ingram, R. 2010, 'The naturalization to invasion transition: Are there introduction-history correlates of invasiveness in exotic plants of Australia?', Austral Ecology, vol. 35, no. 6, pp. 695-703.
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Of the large number of exotic plant species that become naturalized in new geographic regions, only a subset make the transition to become invasive. Identifying the factors that underpin the transition from naturalization to invasion is important for our understanding of biological invasions. To determine introductionhistory correlates of invasiveness among naturalized plant species of Australia, we compared geographic origin, reason for introduction, minimum residence time and growth form between naturalized non-invasive species and naturalized invasive plant species. We found that more invasive species than expected originated from South America and North America, while fewer invasive species than expected originated from Europe and Australasia. There was no significant difference between invasive and non-invasive species with respect to reason for introduction to Australia. However, invasive species were significantly more likely to have been resident in Australia for a longer period of time than non-invasive species. Residence times of invasive species were consistently and significantly higher than residence times of non-invasive species even when each continent of origin was considered separately. Furthermore, residence times for both invasive and non-invasive species varied significantly as a function of continent of origin, with species from South America having been introduced to Australia more recently on average than species from Europe, Australasia and North America.
Phillips, M., Murray, B.R., Pysek, P., Pergl, J., Jarosik, V., Chytry, M. & Kuhn, I. 2010, 'Plant species of the Central European flora as aliens in Australia', Preslia, vol. 82, no. 4, pp. 465-482.
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The Central European flora is an important source pool of plant species introduced to many regions throughout theworld. In this study,we identified a total of 759 plant species of the Central European flora that are currently recognized as alien species in Australia. We explored temporal patterns of introduction of these species to Australia in relation to method of introduction, growth form, naturalization status and taxonomy. Across all species, substantially larger numbers of species were introduced between 1840 and 1880 as well as between 1980 and the present, with a small peak of introductions within the 1930s. These patterns reflect early immigration patterns to Australia, recent improvements in fast and efficient transportation around the globe, and emigration away from difficult conditions brought about by the lead up to the Second World War respectively. We found that the majority of species had deliberate (69%) rather than accidental (31%) introductions and most species have not naturalized (66% casual species, 34% naturalized species). A total of 86 plant families comprising 31 tree species, 91 shrub species, 533 herbaceous species and 61 grass species present in Central Europe have been introduced to Australia. Differential patterns of temporal introduction of species were found as a function of both plant family and growth form and these patterns appear linked to variation in human migration numbers to Australia.
Baker, A.C. & Murray, B.R. 2010, 'Relationships between leaf-litter traits and the emergence and early growth of invasive Pinus radiata seedlings', Weed Research, vol. 50, no. 6, pp. 586-596.
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Pinus radiata is an invasive weed in Australia that spreads from plantations and establishes in surrounding native eucalypt woodlands. To determine factors linked to the invasiveness of P. radiata, we compared emergence and growth traits of P. radiata seedlings at five different depths of leaf litter under pine needles, native eucalypt leaves and an equal mix of the two. Seedling emergence, height, survival and establishment were significantly reduced as leaf-litter depth increased. Seedlings had lower root:shoot ratios and higher specific leaf area (SLA) under deeper litter treatments, shifts linked to the provision of more surface area for light capture and greater light access by seedlings. Total seedling dry weight was highest in treatments with 1 cm of litter cover due to greater moisture retention provided by a small amount of leaf litter outweighing the costs of seedling penetration through leaf litter. Importantly, we found that at any given depth of leaf litter, there were no significant differences in emergence and growth traits between pine, eucalypt or mixed leaf-litter treatments. The ability of P. radiata seedlings to succeed equally well under a range of different leaf-litter types is undoubtedly an important trait linked to its invasiveness. Given ethical concerns of introducing highly invasive species, such as P. radiata into remnant native woodland in field-based studies, glasshouse research is highly desirable and invaluable in elucidating important factors underpinning the invasiveness of weed species such as P. radiata.
Nevill, J.C., Hancock, P., Murray, B.R., Ponder, W.F., Humphreys, W.F., Phillips, M. & Groom, P.K. 2010, 'Groundwater-dependent ecosystems and the dangers of groundwater overdraft: a review and an Australian perspective', Pacific Conservation Biology, vol. 16, pp. 187-208.
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In many parts of the world, access to groundwater is needed for domestic, agricultural and industrial uses, and global groundwater exploitation continues to increase. The significance of groundwater in maintaining the health of rivers, streams, wetlands and associated vegetation is often underestimated or ignored, resulting in a lack of scrutiny of groundwater policy and management. It is essential that management of groundwater resources considers the needs of natural ecosystems, including subterranean. We review the limited Australian literature on the ecological impacts of groundwater overdraft and place Australian information within an international context, focusing on lentic, lotic, stygobitic and hyporheic communities as well as riparian and phreatophytic vegetation, and some coastal marine ecosystems. Groundwater overdraft, defined as abstracting groundwater at a rate which prejudices ecosystem or anthropocentric values, can substantially impact natural communities which depend, exclusively or seasonally, on groundwater. Overdraft damage is often underestimated, is sometimes irreversible, and may occur over time scales at variance to those used by water management agencies in modelling, planning and regulation. Given the dangers of groundwater overdraft, we discuss policy implications in the light of the precautionary principle, and make recommendations aimed at promoting the conservation of groundwater-dependent ecosystems within a sustainable use context.
Robson, T.C., Baker, A.C. & Murray, B.R. 2009, 'Differences in leaf-litter invertebrate assemblages between radiata pine plantations and neighbouring native eucalypt woodland', Austral Ecology, vol. 34, no. 4, pp. 368-376.
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We investigated the structure, composition and environmental correlates of leaf-litter invertebrate assemblages in Pinus radiata plantations and in neighbouring native eucalypt woodland in the Jenolan Caves Karst Conservation Reserve, south-east Australia. Invertebrate assemblages of plantations were compared with remnant eucalypt woodland located well away from the influence of plantations to determine the direct effects of plantations as a result of habitat-replacement with a non-native plantation species. We also included in our comparisons edge habitat of eucalypt woodland located immediately adjacent to plantations. This unique edge habitat is exposed to the intrusion of large volumes of pine leaf-litter from plantations, which has the potential to affect indirectly invertebrate assemblages of surrounding woodland. We found that species richness of invertebrates was significantly lower in pine plantations compared with remnant eucalypt woodland. There was a complete absence of species from 12 invertebrate orders that were found in surrounding eucalypt woodland. A rich and abundant native plant understorey that provides increased habitat heterogeneity is the most likely explanation for the richer invertebrate assemblage found in remnant eucalypt woodland. The total abundance of all invertebrate taxa in pine plantations in winter was significantly higher than in remnant eucalypt woodland, pine-litter edges and pine-free edges. Plantations were characterized by particularly high abundances of species in two orders, Acari and Collembola. High abundances of acarine and collembolan species in plantations were associated with a decompositional environment represented by comparatively higher moisture contents and higher C : N ratios of both leaf-litter and soil, higher soil conductivity and lower soil pH.
Wang, Y., Li, Y., Wu, Z. & Murray, B.R. 2009, 'Insular shifts and trade-offs in life-history traits in pond frogs in the Zhoushan Archipelago, China', Journal Of Zoology, vol. 278, no. 1, pp. 65-73.
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Island and mainland populations of animal species often differ strikingly in life-history traits such as clutch size, egg size, total reproductive effort and body size. However, despite widespread recognition of insular shifts in these life-history traits in birds, mammals and reptiles, there have been no reports of such life-history shifts in amphibians. Furthermore, most studies have focused on one specific life-history trait without explicit consideration of coordinated evolution among these intimately linked life-history traits, and thus the relationships among these traits are poorly studied. Here we provide the first evidence of insular shifts and trade-offs in a coordinated suite of life-history traits for an amphibian species, the pond frog Rana nigromaculata. Life-history data were collected from eight islands in the Zhoushan Archipelago and neighboring mainland China. We found consistent, significant shifts in all life-history traits between mainland and island populations. Island populations had smaller clutch sizes, larger egg sizes, larger female body size and invested less in total reproductive effort than mainland populations. Significant negative relationships were found between egg size and clutch size and between egg size and total reproductive effort among frog populations after controlling for the effects of body size. Therefore, decreased reproductive effort and clutch size, larger egg size and body size in pond frogs on islands were selected through trade-offs as an overall life-history strategy. Our findings contribute to the formation of a broad, repeatable ecological generality for insular shifts in life-history traits across a range of terrestrial vertebrate taxa.
Cadotte, M.W., Hamilton, M.T. & Murray, B.R. 2009, 'Phylogenetic relatedness and plant invader success across two spatial scales', Diversity And Distributions, vol. 15, no. 3, pp. 481-488.
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Successful invaders often possess similar ecological traits that contribute to success in new regions, and thus under niche conservatism, invader success should be phylogenetically clustered. We asked if the degree to which non-native plant species are phylogenetically related is a predictor of invasion success at two spatial scales. Australia - the whole continent and Royal National Park (south-eastern Australia). We used non-native plant species occupancy in Royal National Park, as well as estimated continental occupancy of these species from herbarium records. We then estimated phylogenetic relationships using molecular data from three gene sequences available on GenBank (matK, rbcL and ITS1). We tested for phylogenetic signals in occupancy using Blomberg's K. Whereas most non-native plants were relatively scarce, there was a strong phylogenetic signal for continental occupancy, driven by the clustering of successful species in Asteraceae, Caryophyllaceae, Poaceae and Solanaceae. However, we failed to detect a phylogenetic signal at the park scale. Our results reveal that at a large spatial scale, invader success is phylogenetically clustered where ecological traits promoting success appear to be shared among close relatives, indicating that phylogenetic relationships can be useful predictors of invasion success at large spatial scales. At a smaller, landscape scale, there was no evidence of phylogenetic clustering of invasion success, and thus, relatedness plays a much reduced role in determining the relative success of invaders.
Moles, A., Wright, I.A., Pitman, A.J., Murray, B.R. & Westoby, M. 2009, 'Is there a latitudinal gradient in seed production?', Ecography, vol. 32, no. 1, pp. 78-82.
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We compiled data from seed rain studies at 33 sites from around the world to determine whether the greater mean seed mass of tropical plants is associated with production of fewer seeds per square meter of ground. We found no significant linear relationship between latitude and annual seed rain density, but found some evidence for a mid-latitude peak in seed rain density (quadratic relationship, p=0.018; R-2=0.23). Combining seed rain data with seed mass data suggests that vegetation at the equator produces between 19 and 128 times more total mass of seed per year than does vegetation at 60 degrees. This gradient in seed production would far outweigh the doubling in net primary productivity (NPP) over the same range of latitudes. Thus, our (admittedly small) dataset suggests that tropical vegetation allocates a much greater proportion of NPP to reproduction. This raises two important questions for the future: 1) why might tropical vegetation commit more energy to seed production than vegetation further from the equator? 2) What aspect of plant growth might receive proportionally less energy in tropical ecosystems?
Zhang, F., Li, Y., Guo, Z.P. & Murray, B.R. 2009, 'Climate warming and reproduction in Chinese alligators', Animal Conservation, vol. 12, no. 2, pp. 128-137.
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The Chinese alligator Alligator sinensis is a critically endangered species endemic to China, and one of the most endangered crocodilian species in the world. Like many other reptiles, important aspects of alligator biology such as foraging, timing of hibernation, breeding and the sex ratio of offspring are all affected by temperature variation. We examined the effects of long-term temperature change on oviposition dates and clutch sizes of the Chinese alligator in a semi-natural facility in southern China. Our study focused on two captive generations including an old breeding generation captured from the wild and a generation composed of their F1 offspring. Median oviposition date shifted to earlier in the year and mean clutch size was larger for both generations as the monthly mean air temperature in April increased over the 19 years of data collection. We observed a mean advance in oviposition date of 10 days for the old breeding generation from 1987 to 2005 and 8 days for both generations from 1991 to 2005. Correspondingly, clutch sizes for the two generations also increased during this period. There were no differences in median oviposition dates and clutch sizes between the two generations from 1991 to 2005. Our results suggest that Chinese alligators have responded to increasing global temperatures. Our findings also suggest that recent increasing global temperatures have the potential to have a substantial effect on Chinese alligator populations in the wild, thus prompting an urgent need for field monitoring of the effects of global warming on this endangered alligator species.
Wallach, A., Murray, B.R. & O'neill, A. 2009, 'Can threatened species survive where the top predator is absent?', Biological Conservation, vol. 142, no. 1, pp. 43-52.
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Top predators have been described as highly interactive keystone species. Their decline has been linked to secondary extinctions and their increase has been linked to ecological restoration. Several authors have recently argued that the dingo Canis lupus dingo is another example of a top predator that maintains mesopredators and generalist herbivores at low and stable numbers, thereby increasing biodiversity and productivity. Due to the sensitivity of many Australian species to introduced mesopredators and herbivores, the top predator hypothesis predicts that threatened species will not survive where dingoes are rare or absent. However, several threatened species have survived inside the Dingo Barrier Fence (DBF). We present a new view on the survival of the yellow-footed rock-wallaby Petrogale xanthopus xanthopus and the malleefowl Leipoa ocellata inside the DBF where the dingo is considered very rare, or in areas where the dingo is believed to have been eradicated several decades ago. We found that dingoes co-occurred with both threatened species. Dingoes were present at all wallaby colonies surveyed and occurred throughout their range. The most common predator detected in areas inhabited by the wallabies was in fact the dingo, and we found no significant difference between dingo abundance inside compared to outside the DBF. Malleefowl nests were found to be scent marked by dingoes at the three sites that we surveyed, despite these sites being close to human settlement and sheep farms, and in small and fragmented patches of wilderness. These findings provide further evidence for an association between the presence of dingoes and the survival of threatened species, which is in agreement with the top predator hypothesis.
Murray, B.R., Baker, A.C. & Robson, T.C. 2009, 'Impacts of the replacement of native woodland with exotic pine plantations on leaf-litter invertebrate assemblages: a test of a novel framework', International Journal of Ecology, vol. 2009, no. 49035, pp. 1-6.
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We present an empirical comparison of invertebrate community sturcture between aereras of undisturbed native eucalypt woodland and areas that have been cleared and replaced with plantations of exotic radiata pine (Pinus radiata). Implementation of a novel conceptual framework revealed that both insect (in autumn) and arachnid (in winter) assemblages demonstrated inhibition in response to the pine plantations.
Hills, N., Hose, G.C., Cantlay, A.J. & Murray, B.R. 2008, 'Cave invertebrate assemblages differ between native and exotic leaf litter', Austral Ecology, vol. 33, no. 3, pp. 271-277.
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Allochtonous leaf litter is an important source of energy and nutrients for invertebrates in cave ecosystems. A change to the quality or quantity of litter entering caves has the potential to disrupt the structure and function of cave communities. In thi
Yunusa, I.A., Veeragathipillai, M., DeSilva, L., Eamus, D., Murray, B.R. & Nissanka, S. 2008, 'Growth and elemental accumulation by canola on soil amended with coal fly ash', Journal Of Environmental Quality, vol. 37, no. 3, pp. 1263-1270.
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To explore the agronomic potential of an Australian coal fly ash, we conducted two glasshouse experiments in which we measured chlorophyll fluorescence, CO2 assimilation (A), transpiration, stomatal conductance, biomass accumulation, seed yield, and elem
Harris, C.J., Murray, B.R., Hose, G.C. & Hamilton, M.T. 2007, 'Introduction history and invasion success in exotic vines introduced to Australia', Diversity And Distributions, vol. 13, no. 4, pp. 467-475.
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The ecological damage caused by invasive vines poses a considerable threat to many natural ecosystems. However, very little data are available for this potentially environmentally destructive functional group in Australia. In order to address this paucity of information, we assembled the first inventory of exotic vines thathave become established in natural ecosystems across Australia. The influence that introduction history attributes, variables that relate to the introduction of a species to a new area, may have on the occurrence and distribution of exotic vines was also determined. We asked whether the continent of origin, reason for introduction and residence tiem related to the prevalence and distribution of exotic vines across Asutralia. A total of 179 exotic climbing plant species from 40 difference families were found to have become established across continental Australia. However, five families accounted for over 50% of thes species. Most exotic vines originated from South America and were introduced for ornamental purposes. The length of time in which an exotic vine had been present in tis new range was significantly related to its distribution, with a positive relationship found between residence time and area of occupancy across the continent. No other introduction history attribute was significantly related to the area of accup[ancy ro distribution of a species. This suggests that while the trends found among introduction history attributes are important in explaining the prevalence of exotic vines in Australia, opnly residence time is currently a useful predictor of their future success.
Baker, A.C., Murray, B.R. & Hose, G.C. 2007, 'Relating pine-litter intrusion to plant-community structure in native eucalypt woodland adjacent to Pinus radiata (Pinaceae) plantations', Australian Journal Of Botany, vol. 55, no. 5, pp. 521-532.
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Radiata pine ( Pinus radiata D. Don) plantations are often found in close proximity to vegetation set aside for biodiversity conservation. We examined the intrusive effects of radiata pine beyond the confines of plantations by quantifying the penetration
Eamus, D., Froend, R., Loomes, R., Hose, G.C. & Murray, B.R. 2006, 'A functional methodology for determining the groundwater regime needed to maintain the health of groundwater-dependent vegetation', Australian Journal Of Botany, vol. 54, no. 2, pp. 97-114.
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In the past, the phrase environmental allocations of water has most often been taken to mean allocation of water to rivers. However, it is now accepted that groundwater-dependent ecosystems are an important feature of Australian landscapes and require an
Murray, B.R., Hose, G.C., Eamus, D. & Licari, D.D. 2006, 'Valuation of groundwater-dependent ecosystems: a functional methodology incorporating ecosystem services', Australian Journal Of Botany, vol. 54, no. 2, pp. 221-229.
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Groundwater-dependent ecosystems (GDEs) are ecosystems that must have access to groundwater to maintain their ecological structure and function. Rapidly expanding numbers of humans are placing increased demands on groundwater for consumption, industry an
Baker, A.C., Hose, G.C. & Murray, B.R. 2006, 'Vegetation responses to Pinus radiata (D. Don) invasion: A multivariate analysis using principal response curves', Proceedings Of The Linnean Society Of New South Wales, vol. 127, pp. 191-197.
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Radiata pine (Pinus radiata D. Don) has been introduced to many new regions outside its native range as a plantation species. Plantations are frequently located adjacent to native vegetation. This proximity allows not only pine wildings, but also large a
Cadotte, M.W., Murray, B.R. & Lovett-doust, J. 2006, 'Ecological patterns and biological invasions: Using regional species inventories in macroecology', Biological Invasions, vol. 8, no. 4, pp. 809-821.
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Macroecology depends heavily on a comparative methodology in order to identify large-scale patterns and to test alternative hypotheses that might generate such patterns. With the advent and accessibility of large electronic databases of species and their
Hose, G.C., Murray, B.R., Park, M.L., Kelaher, B.P. & Figueira, W.F. 2006, 'A meta-analysis comparing the toxicity of sediments in the laboratory and in situ', Environmental Toxicology And Chemistry, vol. 25, no. 4, pp. 1148-1152.
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Sediment toxicity tests in the laboratory are an important part of ecological risk assessments, yet how they relate to sediment toxicity in situ has rarely been explored. Using meta-analysis, we examined differences in the toxicity of sediment tested in
Wu, Z., Li, Y. & Murray, B.R. 2006, 'Insular shifts in body size of rice frogs in the Zhoushan Archipelago, China', Journal Of Animal Ecology, vol. 75, no. 5, pp. 1071-1080.
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1. Differences in body size between mainland and island populations have been reported for reptiles, birds and mammals. Despite widespread recognition of insular shifts in body size in these taxa, there have been no reports of such body size shifts in am
Yunusa, I.A., Eamus, D., De Silva, D.L., Murray, B.R., Burchett, M., Skilbeck, C.G. & Heidrich, C. 2006, 'Fly-ash: An exploitable resource for management of Australian agricultural soils', Fuel, vol. 85, no. 16, pp. 2337-2344.
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Agricultural soils in Australia have inherent limitations of structural and nutritional nature that pose major constraints to crop productivity. These soils are still productive due to intensive management that involves routine treatments with lime and g
Cadotte, M.W., Murray, B.R. & Lovett-doust, J. 2006, 'Evolutionary and ecological influences of plant invader success in the flora of Ontario', Ecoscience, vol. 13, no. 3, pp. 388-395.
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It is not clear why some species are able to naturalize and spread in a new region while so many other species are not. Several general properties have been reported for successful non-indigenous plant species (NIPS). These include presence of a lag time
Murray, B.R. & Hose, G.C. 2005, 'The interspecific range size-body size relationship in Australian frogs', Global Ecology And Biogeography, vol. 14, no. 4, pp. 339-345.
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Aim There is substantial residual scatter about the positive range size-body size relationship in Australian frogs. We test whether species' life history and abundance can account for this residual scatter. Location Australia. Methods Multiple regression
Hamilton, M.T., Murray, B.R., Cadotte, M.W., Hose, G.C., Baker, A.C., Harris, C.J. & Licari, D.D. 2005, 'Life-history correlates of plant invasiveness at regional and continental scales', Ecology Letters, vol. 8, no. 10, pp. 1066-1074.
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We implemented cross-species and independent-contrasts multiple regression models to compare life-history correlates of invasion success between regional and continental spatial scales among non-native plants of eastern Australia. We focussed on three li
Murray, B.R. & Hose, G.C. 2005, 'Life-history and ecological correlates of decline and extinction in the endemic Australian frog fauna', Austral Ecology, vol. 30, no. 5, pp. 564-571.
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Frog populations are rapidly disappearing throughout the world. An important issue for ecologists to resolve is why some frog species are more susceptible to decline than others. Here, we performed a comparative study of the endemic Australian frog fauna
Eamus, D., Macinnis-Ng, C.M., Hose, G.C., Zeppel, M.J., Taylor, D.T. & Murray, B.R. 2005, 'Ecosystem services: an ecophysiological examination', Australian Journal Of Botany, vol. 53, no. 1, pp. 1-19.
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This review aims to discuss ecosystem services, provide illustrative case studies at catchment and local scales and present future research needs. This review discusses the following: ( 1) Ecosystem services (ES) are those goods and services that are pro
Murray, B.R., Kelaher, B.P., Hose, G.C., Figueira, W.F. & Leishman, M.R. 2005, 'A meta-analysis of the interspecific relationship between seed size and plant abundance within local communities', Oikos, vol. 110, no. 1, pp. 191-194.
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Pohlman, C., Nicotra, A. & Murray, B.R. 2005, 'Geographic range size, seedling ecophysiology and phenotypic plasticity in Australian Acacia species', Journal of Biogeography, vol. 32, no. 2, pp. 341-351.
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The dergee to which eco-pysiological traits critical to seedling establishment are realted to differences in geographic range size among species is not well understood. Here, we first tested the idea that seedling eco-physiological attributes associated with establishments differ between narrowly distributed and geographically widespread plant species. Secondly, we tested the notion that species occupying wide geographic ranges have greater phenotypic plasticity in response to the environment than contrasted species withmore resticted distribution.
Hose, G.C., Gordon, G., McCullough, F.E., Pulver, N. & Murray, B.R. 2005, 'Spatial and rainfall related patterns of bacterial contamination in Sydney Harbour estuary', Journal of Water and Health, vol. 3, pp. 349-358.
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Water qaulity in recreational areas in Sydney Harbour, Australia, was analysed first into identify spatial patterns in faecal coliform and entercocci densities, and then to determine the relationship between bacterial densities and catchment rainfall. Non-metric multidimensional scaling separated sites closets to themouth of the harbour from those further up the harbour's west and north-west arms. Sites closest to the harbour mouth generally had lower frequencies of high bacterial densities that exceeded median water quality guideline values. We attribute this to greater tidal flushing at sites closer to the harbour mouth.
Murray, B.R. & Lepschi, B.J. 2004, 'Are locally rare species abundant elsewhere in their geographical range?', Austral Ecology, vol. 29, pp. 287-293.
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Ecologists have long sought to understand why some species are rare and others common. For the most part, inconsistent relationships between local rarity and underlying mechanisms have emerged. One possibility for this inconsistency is that locally rare species may not always be rare. Howeverm it is largely unknown whether most locally rare species in a community possess the capacity to become abundant elsewhere in their geographical range. Here we identified 57 locally rare plant species of open forest in south-eastern Australia. We found that mopst o these species (91%)occurred in higher abundance at other sites within their geographical range 9somewhere-abundant species), while the remaining small percentage of locally rare species were consistently rare (everywhere sparse species). Somewhere-abundant species had significantly smaller seeds on average than everywhere-sparse species in cross-specis regression analysis. This pattern was not maintianed when the influence of other life-history attributes was controlled for, or when phylogenetic relatedness among species was considered explicitly in phylogenetic regression analysis. In both cross-species and phylogenetic regressions, somewhere-abundant and everywhere-sparse species did not differ significantly with respect to growth form, height, regeneration-after-fire strategy, or dispersal. Pur findings provide further evidence for the notion that theories to account for local rarity which are couched in terms of within-community interactions alone are incomplete for the majority of species, because they need to account for different outcomes in different places.
McPherson, S., Eamus, D. & Murray, B.R. 2004, 'Seasonal impacts on leaf attributes of several tree species growing in three diverse ecosystems of south-eastern Australia', Australian Journal Of Botany, vol. 52, pp. 293-301.
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Patterns of leaf attributes were examined for six woody species growing in a eucalypt woodland, a mangorve, or a heathland in coastal NSW, Australia, during winter and summer. It was found that the rate of assimilation per unit of dry mass (Amass) of the mangrove species was largest, woodland species exhibiting an intermedaite rate and heathland species the smallest values of Amass. Mean habitat Amass did not change from winter to summer in the woodland or mangrove species but increased significantly in the heathland species. Averag specific leaf area (SLA) was largest for the mangrove species and smallest for the heathland species, with woodland species showing intermediate values. SLA of all species within a habitat did not change from winter to summer.Mean foliar nitrogen content (Nmass of the mangrove species was highest, intermediate for woodland species and lowest for heathland species. NMass was significantly related to Amass in both summer and winter and the individual slopes for this relationship in the summer and winter differed. In contrast, a common slope waws fitted to the relationship between SLA and Amass for the two seasons. A common slope between seasons was also shown for the relationship between SLA and NMass. There was no significant diffeence in slope elevation between summer and winter for the SLA v. Nmass relationship. Trends within relationships among leaf attributes were the same as those found for a wide range of plant species worldwide, but the absolute values were loer than those foudn elsewhere. Therefore the global relationships in terms of trends (positive or negative) that have been determined overseas apply in Australia but the elevation of th sloep and the magnitidue of the slope are reduced (Amass v. Nmass) or increased (Amass v. SLA and Nmass v. SLA) compared with global trends.
Murray, B.R., Brown, A.H., Dickman, C.R. & Crowther, M.S. 2004, 'Geographical gradients in seed mass in relation to climate', Journal Of Biogeography, vol. 31, no. 3, pp. 379-388.
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To determine whether latitudinal and longitudinal gradients in seed mass are related to variation in climatic features including temperature, solar radiation and rainfall. Location Australia. Methods Seed mass was estimated from over 1600 provenances covering the latitudinal and longitudinal extents of 34 perennial Glycine taxa in Australia. Climatic data were obtained from ANUCLIM 5.1 for collection locations based on long-term meteorological records across Australia. These climatic data were subject to principal components analysis to extract three components as climatic indices. Generalized linear models were used in three separate sets of analyses to evaluate whether seed mass+latitude and seed mass+longitude relationships persisted after taking climatic variation into account. First, relationships were examined across species in analyses that did not explicitly consider phylogenetic relationships. Secondly, phylogenetic regressions were performed to examine patterns of correlated evolutionary change throughout the Glycine phylogeny. Within-species analysis was also performed to examine consistency across different taxonomic levels. Results Geographical variation in seed mass among species was related primarily to temperature and solar radiation, while rainfall was much less influential upon seed mass. Partialing out the influence of temperature and solar radiation in models resulted in the disappearance of significant seed mass+latitude and seed mass+longitude relationships. Patterns within species were generally consistent with patterns among species. However, in several species, factors additional to these climatic variables may contribute to the origin and maintenance of geographical gradients in seed mass, as significant seed mass+latitude and seed mass+longitude relationships remained after controlling for the influence of climatic variables.
Hose, G.C., Murray, B.R. & Eamus, D. 2004, 'Water quality guidelines to protect groundwater-dependent ecosystems', Ecological Management & Restoration, vol. 5, no. 1, pp. 78-80.
Groundwater-dependent ecosystems (GDEs) are those ecosystems that depend on the input of groundwater to maintian their current composition and function (SKM 2001: Murray et al 2003) Six types of GDEs have been identified in Australia (SKM 2001): terrestrial vegetation; river base flow systems; aquifer and cave ecosystems; wetlands; terrestrial fauna (that depend on groundwater as a drinking water supply); and estuarine and newar-shore marine ecosystems. By defenition, GDEs depend on a source of water for which there are currentlyno water quality guidelines designed specifically to ensure ecosystem protection. Some GDEs are likely to be protected by water quality guidelines for surface ecosystems but for others, the level of protection offered by surface water quality guidelines is unknown. Here we consider the application of existing water quality guidelines to GDEs and the future need for guidelines tailored specifically to GDEs.
Zeppel, M.J., Murray, B.R., Barton, C. & Eamus, D. 2004, 'Seasonal responses of xylem sap velocity to VPD and solar radiation during drought in a stand of native trees in temperate Australia', Functional Plant Biology, vol. 31, pp. 461-470.
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Xylem sap velocity of two dominant tree species, Eucalyptus crebra F. Muell and Callitris glaucophylla J. Thopson & LAS Johnson, in a native remnant forest of eastern Australia was measured in winter and summer during a rpolonged (> 12 months) and extensive drought. The influence of vapour pressure deficit (VPD) and solar radiation levels onthe velocity of sap was determined. Pronounced hysteresis in sap velocity was observed in both species as a function of VPD and solar radiation. However the rotation of the hysteresis curve was clockwise for the response of sap velocity to VPD but anti-clockwise in the response of sap bvelocity to radiation levels. A possible reason for this difference is discussed. The degree of hysteresis (area bounded by the curve) was larger for the VPD response than the response to solar radiation and also varied with season. A simple linear model was able to predict sap velocity from knowledge of VPD and solar radiation in winter and summer. The consistent presence of hysteresis in the response to sap velocity to VPD and solar radiation suggests that large temporal and spatial models of vegetation water use may require soem provision for the different responses of sap velocity, and hence water use, to VPD and solar radiation, between morninga nd afternoon and between seasons.
Hose, G.C., Murray, B.R. & Eamus, D. 2004, 'Water quality guidelines to protect groundwater-dependent ecosystems', Ecological Management & Restoration, vol. 5, pp. 78-80.
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Murray, B.R., Brown, A.H. & Grace, J.P. 2003, 'Geographic gradients in seed size among and within perennial Australian Glycine species', Australian Journal Of Botany, vol. 51, no. 1, pp. 47-56.
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Murray, B.R. 2003, 'Reproductive characteristics of Road-verge and Reserve-interior populations of Exocarpos cupressiformis Labill (Santalaceae)', The Victorian Naturalist, vol. 120, no. 1, pp. 10-14.
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Murray, B.R., Zeppel, M.J., Hose, G.C. & Eamus, D. 2003, 'Groundwater-dependent ecosystems in Australia: it's more than just water for rivers', Ecological Management & Restoration, vol. 4, no. 2, pp. 110-113.
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Murray, B.R. & Leishman, M.R. 2003, 'On the relationship between seed mass and species abundance in plant communities', OIKOS, vol. 101, no. 3, pp. 643-645.
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Zeppel, M.J., Murray, B.R. & Eamus, D. 2003, 'The potential impact of dryland salinity on the threatened flora and fauna of New South Wales', Ecological Management & Restoration, vol. 4 (Sup.), pp. 53-59.
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Murray, B.R., Thrall, P.H., Gill, A.M. & Nicotra, A. 2002, 'How plant life-history and ecological traits relate to species rarity and commonness at varying spatial scales', Austral Ecology, vol. 27, pp. 291-310.
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Murray, B.R., Thrall, P.H. & Lepschi, B.J. 2002, 'Relating species rarity to life history in plants of eastern Australia', Evolutionary Ecology Research, vol. 4, pp. 937-950.
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Murray, B.R. 2002, 'Book review: Introduction to Plant Population Biology', New Phytologist, vol. 155, pp. 201-202.
Murray, B.R., Thrall, P.H. & Woods, M.J. 2001, 'Acacia Species and Rhizobial Interactions: Implications for Restoration of Native Vegetation', Ecological Management & Restoration, vol. 2, no. 3, pp. 213-219.
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Leishman, M.R. & Murray, B.R. 2001, 'The relationship between seed size and abundance in plant communities: model predictions and observed patterns', OIKOS, vol. 94, pp. 151-161.
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Recent studies have suggested that seed size and plant abundance in communities are associated. However, inconsistent patterns have emerged from these studies, with varying mechanisms proposed to explain emergent relationships. We employ a theoretical framework, based on key theory lineages of vegetation dynamics and species coexistence, to examine relationships between species abundance and seed size. From these theory lineages, we identified four models and their predictions: the Seed size/number trade-off model (SSNTM), the Succession model (SM), the Spatial competition model (SCM), and the Lottery model (LM). We then explored empirical evidence from ten diverse plant communities for seed size and abundance patterns, and related these patterns to model predictions. The SSNTM predicts a negative correlation between seed size and abundance.
Falster, D., Murray, B.R. & Lepschi, B. 2001, 'Linking abundance, occupancy and spatial structure: an empirical test of a neutral model in an open-forest woody plant community in eastern Australia', Journal Of Biogeography, vol. 28, pp. 317-323.
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Murray, B.R. & Gill, A.M. 2001, 'A comparative study of interspecific variation in fruit size among Australian eucalypts', Ecography, vol. 24, no. 6, pp. 651-658.
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We examined variation in woody fruit size among 362 Australian Eucalyptus species with respect to predictions relating fruit size to fire exposure and rainfall. Predictions for fruit size variation were established that focussed on selection for small or
Thrall, P.H., Murray, B.R., Watkin, E.L., Woods, M.J., Baker, K., Burdon, J.J. & Brockwell, J. 2001, 'Bacterial partnerships enhance the value of native legumes in rehabilitation of degraded agricultural lands', Ecological Management & Restoration, vol. 2, no. 3, pp. 233-235.
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A consequence of the generally low nutrient levels of Australian soils is that relationships between plants and their microbial symbionts (mycorrhizal fungi as weJl as nitrogen-fixing bacteria) have particular significanc:e for conservation management, sustainable agriculture, and eco~ystem rehabilitation. Shrubby legumes in the Fabaceae (e.g. Acacia, Oaviesia, Oil/wynia, Oxylobium, Hovea and Pultenaea) constitute a major group of plants that form nitrogen- fixing (N2-fixin@) partnerships with root-nodule bacteria (species of rhizobia). These taxa are found throughout Australia, and are frequently a dominant part of undisturbed ecosystems, both in terms of abundance as well as overall biomass.
Thrall, P.H., Murray, B.R., Watkin, E.L., Woods, M.J., Baker, K., Burdon, J.J. & Brockwell, J. 2001, 'Bacterial partnerships enhance the value of native legumes in rehabilitation of degraded agricultural lands', Ecological Management & Restoration, vol. 2, pp. 233-235.
A consequence of the generally low nutrient levels of Australian soils is that relationships between plants and their microbial symbionts (mycorrhizal fungi as well as nitrogen-fixing bacteria) have particular significance for conservation management, sustainable agriculture, and ecosystem rehabilitation. Shrubby legumes in the Fabaceae (e.g. Acacia, Daviesia, Dillwynia, Oxylobium, Hovea and Pultenaea) constitute a major group of plants that form nitrogen- fixing (N2-fixing) partnerships with root-nodule bacteria (species of rhizobia). These taxa are found throughout Australia, and are frequently a dominant part of undisturbed ecosystems, both in terms of abundance as well as overall biomass.
Murray, B.R. & Westoby, M. 2000, 'Properties of species in the tail of rank-abundance curves: The potential for increase in abundance', Evolutionary Ecology Research, vol. 2, no. 5, pp. 583-592.
It has recently been shown that most low-abundance species at a location are substantially more abundant somewhere else within their geographical range (somewhere-abundant). Fewer than 10% are everywhere-sparse Here, two everywhere-sparse species from dr
Murray, B.R. & Dickman, C.R. 2000, 'Relationships between body size and geographical range size among Australian mammals: has human impact distorted macroecological patterns?', Ecography, vol. 23, no. 1, pp. 92-100.
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Extinction and artificial reduction in the size of geographical ranges of many species have occurred extensively across the globe because of human activities. In particular, Australian mammals have suffered heavily in the last two hundred years, with the highest number of reported cases of mammal extinctions anywhere. In the present study, we investigated the extent to which human impact has affected contemporary macroecological patterns in Australian terrestrial mammals. After examining patterns relating to body size and range size among the contemporary mammal fauna, we removed the effects of the last two hundred years of human impact by exploring patterns in the pre-European assemblage. This permitted us to determine whether contemporary macroecological patterns are distortions of pre-European patterns. In contrast to the expected pattern of a significant positive relationship between body size and range size, our results showed no significant association for the complete fauna in both cross-species and phylogenetic analyses, even when data were corrected for species extinctions and range reductions. Analyses within families and among species with the same dietary strategy revealed three significant positive relationships (Macropodidae, Peramelidae, and herbivores) and one significant negative relationship (insectivores) within the contemporary assemblage that disappeared when the pre-European assemblage was analysed. A positive relationship also emerged in the pre-European assemblage for the Vombatidae that was not apparent in the contemporary fauna. Thus, correcting for human impact revealed important distortions among contemporary macroecological relationships that have been brought about by human-induced range reduction and extinction. These findings not only provide further evidence that the Australian continent presents a unique and valuable opportunity with which to test the generality of macroecological patterns,
Murray, B.R., Rice, B., Keith, D., Myerscough, P.J., Howell, J., Floyd, A., Mills, K. & Westoby, M. 1999, 'Species in the tail of rank-abundance curves', Ecology, vol. 80, no. 6, pp. 1806-1816.
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At focal sites within dry sclerophyll woodland and temperate rain forest, species were identified that were of low local abundance and hence in the tail of the rank-abundance curve. We then asked the question: What proportion of tail species within a giv
Murray, B.R., Dickman, C.R., Watts, C. & Morton, S.R. 1999, 'The dietary ecology of Australian desert rodents', Wildlife Research, vol. 26, no. 4, pp. 421-437.
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Very little systematic information has been collected on the diets of Australian rodents in arid and semiarid regions. The information that is available is restricted generally to short periods of sampling and small sample sizes. Here we review the diets
Murray, B.R. 1998, 'Density-dependent germination and the role of seed leachate', Australian Journal Of Ecology, vol. 23, no. 5, pp. 411-418.
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While density dependence is a central issue in much of plant ecology, it is often overlooked during the crucial seed germination period of the plant life-cycle. Here, patterns of germination in relation to initial seed density for 12 phylogenetically-div
Murray, B.R., Fonseca, C. & Westoby, M. 1998, 'The macroecology of Australian frogs', Journal Of Animal Ecology, vol. 67, no. 4, pp. 567-579.
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The Australian continent provides an important test of macroecological patterns given its unique biota and long-term geographical isolation. However, macro- ecological contributions from the Australian continent are rare. We explored the relationship between abundance and geographical range for Australian frogs (Order Anura) across complete geographical ranges, and investigated how adult body size relates to both abundance and the size of geographical ranges.
Murray, B.R. & Dickman, C.R. 1997, 'Factors affecting selection of native seeds in two species of Australian desert rodents', Journal Of Arid Environments, vol. 35, no. 3, pp. 517-525.
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The preferences for different species of native seeds by two species of Australian desert rodents, the sandy inland mouse, Pseudomys hermannsburgensis, and the spinifex hopping-mouse, Notomys alexis, were investigated. In two sets of cafeteria trials providing low and high numbers of different seed species, both rodent species showed discrimination, preferentially consuming certain seed species, while avoiding others. In one of the two trials, P. hermannsburgensis selected seeds with the highest free water content, while N. alexis showed no clear mechanism of seed choice in either trial. It is suggested that although both species of rodents are omnivorous, P. hermannsburgensis relies more on seeds than does N. alexis, and is thus the more efficient seed harvester.
Murray, B.R., Hume, I. & Dickman, C.R. 1995, 'Digestive tract characteristics of the spinifex hopping-mouse, Notomys alexis and the sandy inland mouse, Pseudomys hermannsburgensis in relation to diet', Australian Mammalogy, vol. 18, pp. 93-97.
Murray, B.R. & Dickman, C.R. 1994, 'Food preferences and seed selection in two species of Australian desert rodents', Wildlife Research, vol. 21, no. 6, pp. 647-655.
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Food preferences of two species of Australian desert rodents, the spinifex hopping-mouse (Notomys alaexis) and the sandy inland mouse (Pseudomys hermannsburgenis), were investigated in cafeteria trials. Both species showed strong preference for inverterbrate material (a beetle, Tenebrio molitor) over the seeds and stems of spinifex (Triodia basedowii), and fungus (Tulostoma sp.). This contrasts with previous reports that these rodents are granivores, and suggests instead that they may be omnivorous. Further investigation of the basis for food choice was carried out in a series of seed prefernce trials, and provided some indication that theater content of food items may underlie diet selection. We suggest that the ability of native rodents to eat a broad range of food types, particularly inverterbrates, has promoted survival in arid regions that have been subjected to disturbance since European settlement.
Murray, B.R. & Dickman, C.R. 1994, 'Granivory and microhabitat use in Australian desert rodents - Are seeds important?', Oecologia, vol. 99, no. 3-4, pp. 216-225.
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The diet and microhabitat use of two species of native Australian desert rodents, the spinifex hopping-mouse Notomys alexis and sandy inland mouse Pseudomys hermannsburgensis, were studied in the Simpson Desert, south-western Queensland. Contrary to expectation, both species were confirmed from analyses of their stomach contents to be omnivorous. The diets of both species varied through time in a similar manner; seeds were important in summer and especially in winter, but in autumn invertebrates constituted nearly 50% and 60% of the diet of N. alexis and P. hermannsburgensis, respectively. Other plant material (root, leaf, floral part, stem) was found in appreciable amounts in the stomach contents of both species, and fungi were identified from a small number of individuals. Both species showed a high degree of overlap in the broad types of food they ingested (seed, plant material, invertebrates); however, there was considerably less overlap in the species of seeds eaten. Analysis of microhabitat use suggested that this difference was due to differential foraging between the species; the larger, bipedal N. alexis forages in the open more than the smaller, quadrupedal P. hermannsburgensis, which is found more commonly in or under hummocks of spinifex grass. Although our findings parallel patterns of morphological specialisation and differential foraging on seeds that have been described within communities of North American heteromyid rodents, we found little evidence that the foraging economics of N. alexis or P. hermannsburgensis should depend solely or primarily on the distribution patterns of seeds. In the absence of dietary information, we suggest that ecological studies of desert rodents which focus solely on granivory, and neglect other important aspects of rodent foraging, can lead to a misinterpretation of species coexistence and community structure.