Long-haul research: benefits for conserving and managing biodiversity ... the Desert Ecology Research Group at ... essay I argue that long-term research.
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Long-haul research: benefits for conserving and managing biodiversity CHRIS R. DICKMAN1
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EVERAL times a year, every year for the last two decades, members of the Desert Ecology Research Group at the University of Sydney have made the long trek to the Simpson Desert in central Australia to continue biological monitoring and carry out experiments on a range of ecological and conservation-related topics. This is long-haul research: long-term biological sampling and experimental work that takes place in distant study sites. This kind of research is unusual in that much ecological inquiry takes place close to home and is completed over short periods — typically three years, which is the duration of most postgraduate projects and research grants from major funding bodies such as the Australian Research Council. If short-term local research is the norm, why should anyone contemplate undertaking multi-year hajjes to remote areas? What are the advantages, the challenges and payoffs from long-haul research? In this essay I argue that long-term research is essential to understand the dynamics and processes that drive ecological systems and provide the insights necessary to conserve them. I then propose that such research is needed most critically in remote areas where losses of species and ecological processes often continue apace, but pass unobserved and unremarked. In Australia, areas that are remote for most of us, both physically and conceptually, are the vast and varied landscapes of the continental interior. In addition to describing natural fluctuations in species populations and the processes that drive them, there is an urgent need to understand how the burgeoning human population and its rapacious need for natural resources is affecting organisms and the communities to which they belong. Some humanimpacts are obvious, such as the destruction of habitat and the overhunting of game. Other impacts, such as the liberation of vast quantities of 1
“greenhouse” gases into the atmosphere that drive climate change, are less visible, at least to some in the community. Long-term studies are needed to quantify the effects of these changes, identify those components of the living world that are most at risk, and ultimately provide guidance about how best to conserve and manage them. How many years should a research project continue before it can be considered long term? If an organism is the focus of study it might be reasonable to suggest that investigators track the organism over at least one generation, and ideally over several generations, so that intergenerational differences in life history, numbers, and overall population performance can be quantified. This may be days or weeks for microorganisms, but for longer-lived organisms such as giant tortoises, large mammals or many trees, decades are required. If the focus is on an ecological community, it might be necessary to monitor its ups and downs through extremes of weather, over longer-term climatic cycles such as the 3–8 year El Niño–Southern Oscillation, or over still longer periods to ensure that the effects of other major drivers are studied. Decades, again, may be needed. There are some excellent examples of multi-decadal research projects, but these are exceptions rather than the rule (e.g., Likens 1989; Grant and Grant 2002, 2010). In practice, studies are often considered long-term if they extend for 10 years or more (e.g., Lindenmayer et al. 2012). SHORT-TERM VS LONG-TERM STUDIES In arguing the value of long-term research I do not wish to negate the contribution that is made by focused, short-term inquiries. Far from it; much research is carried out with short-term goals, and this allows the
progressive testing and refining of hypotheses that in turn provide deep understanding of natural systems. It is just that short-term insights need to be kept in context. To appreciate this, consider the findings of Stuart Pimm and Andrew Redfearn. In 1988 these authors examined census records that had been collated on populations of different species of insects, birds, and mammals for periods of at least 50 years, and found that the longer the studies ran, the more the study populations varied in size. The authors interpreted their findings as evidence for the operation of densityindependent processes that elevate or depress populations irrespective of their size. Of course, these processes — which include fires, floods, droughts and other climatic excesses — have been predicted to increase in intensity and severity under various climate change scenarios over the next several decades. In other words, short-term studies cannot be used to reliably predict long-term trends, and this situation is not about to improve. This is all the more reason to ensure that long-term ecological research, and indeed also the researchers carrying out long-term projects, are supported now rather than later. A positive relationship between time and variance in population size may not be too surprising for animals with short generation times, but what might be expected for long-lived organisms? In our research in central Australia we have monitored the cover of the dominant plant species, Hard Spinifex Triodia basedowii, on the same fixed plots since 1990. Not only does spinifex provide the major ground cover in the study region, it provides habitat for the world’s most diverse assemblages of desert lizards and insectivorous mammals (Pianka 1986; Dickman 2003). The biome also characterizes some 25% of continental Australia. Although individual spinifex plants can live for several decades, our long-term surveys have uncovered
Desert Ecology Research Group, School of Biological Sciences, University of Sydney, NSW 2006, Australia, and the Long Term Ecological Research Network, Australia.
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11 2013). Clearly, short-term studies would have been inadequate to predict the variation in the cover of spinifex and in the composition or abundance of its dependent fauna; almost any 2, 3, 4 or 5 year slice taken from the 22–year dataset would be unlike any other.
order-of-magnitude variation in the ground coverage of spinifex and a pattern of increasing variance in cover as the study progressed (Fig. 1A). Spinifex cover generally increased after heavy rainfall and declined during drought, but an evident pattern of increased between-trip variance as the study progressed (Fig. 1A) is more difficult to explain. Whatever the drivers for the observed pattern, we also recorded associated fluctuations and increased variance in capture rates of several species of spinifex-dependent lizards and mammals (Fig. 1B, Dickman et al. A
BENEFITS OF LONG-TERM ECOLOGICAL RESEARCH In a recent review of long-term ecological research, David Lindenmayer and colleagues (2012) argued that ecologists need to become
more vocal in explaining and advocating the benefits of long-term work so that its importance is better understood. Among the many benefits of long-term ecological research, the authors identified five that were of key value. In the first instance, such research allows us to identify the drivers of ecological systems and describe how the systems respond when they are perturbed. Sometimes the drivers are already known and the primary interest then is to quantify the strength of their effects and determine whether they engender linear or non-linear responses or even
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Fig. 1. A) Percentage cover of Hard Spinifex Triodia basedowii assessed by eye at six fixed quadrats on 3–12 1 ha study plots on Ethabuka Reserve, south-western Queensland, expressed as means ± SE on 3–6 visits to the study area each year from 1990 to 2011. B) Capture rate of the Brush-tailed Mulgara Dasycercus blythi on the same study plots, expressed as mean captures per 100 trap nights (1 trap night = 1 trap open for 1 night) ± SE on 3–6 visits to the study area each year from 1990 to 2011.
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12 become functional only when some threshold in their intensity is reached. In arid systems, for example, rainfall is a known and critically important driver, but its effects usually are strongly non-linear. Small amounts of rain have little or no effect, especially if the free water evaporates before organisms are able to use it. Larger amounts, say 50–100 ml over a few days, will trigger the germination of some seeds and draw small burrowing frogs to the ground surface to feed and re-hydrate. But, in arid Australia at least, flooding rains (=90th percentile) are needed to stimulate dramatic increases in primary productivity, tempt large waterholding frogs to the surface to breed, and provide food that in turn drives irruptions in the numbers of rodents, seed-eating and nectar-feeding birds and their respective predators (Letnic and Dickman 2010). Often, long-term studies also uncover drivers that are completely unexpected. For example, camps of the Grey-headed Flying-fox Pteropus poliocephalus are well known in Melbourne and Sydney, especially in the botanical gardens of both cities. In the Melbourne Botanic Gardens the colony grew rapidly from about a dozen residents in 1986 to 20 000–30 000 animals in 2003. Although commentators had suggested variously that the increase was due to climate change, destruction of habitat elsewhere or increasing competition from the Black Flying-fox P. alecto further north, long-term data on airborne-pollen and plantings of street trees suggested a novel but entirely plausible cause: Melbourne provides more reliable food trees for flying-foxes now than previously, so the animals have responded to an increase in the year-round availability of fruit and nectar (Williams et al. 2006). In Sydney, long-term records show that many species of birds, including Noisy Miners Manorina melanocephala, Rainbow Lorikeets Trichoglossus haematodus, Little Corellas Cacatua sanguinea, and Sulphurcrested Cockatoos C. galerita, have increased dramatically in recent decades (Hoskin 1991); these again have probably responded to the increased plantings of food trees in the urban environment (H. F. Recher, personal communication).
Long-term ecological research can also help to disentangle the separate and interactive effects of different processes that together drive changes in populations and communities. The operation of multiple drivers is not surprising; ecological systems are notoriously — and gloriously — complex. However, the addition of new drivers, such as invasive species, often contributes to system changes that are not welcome. Consider the declining small and medium-sized native mammals of northern Australia. Long-term monitoring and analyses of the effects of predation from introduced and now-feral House Cats Felis catus, poisoning from Cane Toads Rhinella marina, habitat change and disease suggest that no one factor is driving the declines, but rather that combinations of them may well be (Woinarski et al. 2011). In arid regions, similarly, small native mammals decline to very low levels in the aftermath of a wildfire, not because of the effects of the flames directly or even because of the depletion of food and other resources, but because the fire clears groundlevel cover and leaves the animals exposed to high levels of predation from Feral Cats and Red Foxes Vulpes vulpes (Letnic and Dickman 2010). The second key value of long-term ecological research identified by Lindenmayer et al. (2012) is that it facilitates understanding of complex ecosystem phenomena that occur over long periods. The most obvious examples are climatic, especially those associated with climate change. While prolonged periods of extreme dry or hot weather can have dramatic and lethal effects on organisms, more gradual changes in average temperatures and rainfall that affect animal body sizes, plant flowering times, growth rates and perhaps shifts from C3 to C4 modes of photosynthesis (Hughes 2003) will be detectable only with longitudinal research. Long timeframes are needed to assess the complex effects engendered in restoration projects such as when soils are allowed to rebuild after the cessation of agricultural or pastoral activity, or when physical ecosystem engineer species, such as beavers, or apex predators, such as the Grey Wolf Canis lupus, are reintroduced to their former ranges (van Andel and
Aronson 2006). Multi-decadal oceanographic cycles, bioaccumulation of toxins, mutagens, micro, and even nano particles of plastics and other chemicals also will affect organisms and their constituent communities in complex ways, so that long-term datasets will be the only means of measuring and interpreting their effects. Thirdly, long-term data provide the raw materials to develop new theoretical ideas, test existing hypotheses, and validate ecological models in ways that short-term studies cannot do. In arid Australia, for example, repeated visits to sites in the Great Victoria Desert allowed Eric Pianka and colleagues to develop the idea that fire creates heterogeneous habitat that facilitates high lizard diversity, and then to test the concept by comparing long-term population and community trends in burnt and unburnt areas (Pianka 1986; Pianka and Goodyear 2012). Long-term studies have been critical also for developing and testing ideas about rates of evolution and modes of adaptation in changing environments (Grant and Grant 2002, 2010), the shifting effects of bottom-up versus top-down processes (Dickman et al. 2013), and the importance of densitydependent and density-independent processes in regulating the population sizes of animals over time (Pimm and Redfearn 1988). There is an increasing tendency for ecologists to use already-collected datasets and interrogate them to develop and validate models that simulate or predict how species and natural systems behave. Examples include recent analyses of long-term datasets on soils, plants and invertebrates (Silvertown et al. 2006) and small mammals (Stenseth et al. 2003; Zub et al. 2012). Field researchers sometimes view this trend with alarm, but using long-term data in combination with models can both keep the models ‘honest’ and extract new insights that may not have been easy to discern using the raw data alone. As noted by Robert MacArthur, “a theory is a lie which makes you see the truth” (quoted in Lomolino 2000: 5). The fourth of the key values of long-term research recognized by Lindenmayer et al. (2012) is that they are often catalytic: they stimulate
Forum Essay others to review the longitudinal findings obtained in one environment and either extend them in situ or generate predictions that can be tested elsewhere. This approach increases the generality of our understanding of how systems work. Importantly, catalytic effects also can lead to collaborative and multidisciplinary research. Take, for example, the decline in native mammals in northern Australia. Foreshadowed by Recher and Lim (1990), the first quantitative reports of mammalian decline were made by Braithwaite and Muller (1997) from surveys in Kakadu National Park over the period 1986–1993. These latter authors suggested that the decline had been driven by a run of dry seasons. John Woinarski and colleagues subsequently repeated the monitoring, showed that low rainfall could not be supported as an explanation for the declines, and raised the alarm that populations of many species were continuing to fall. The early research involved authors from just CSIRO and the Northern Territory government, but the worrying trends that it reported stimulated much broader collaborations. In 2011, Woinarski was joined by 16 colleagues who contributed to an update and analysis of the ongoing declines (Woinarski et al. 2011). The collaborators were drawn from six of the eight Australian states and territories, and the UK, and represented researchers with wide-ranging expertise from universities as well as government and non-government institutions. Finally, long-term studies are frequently used to underpin policy and decision-making. A most obvious case example here relates to climate change. Long-term records from most parts of the world confirm that sea levels as well as mean minimum and maximum temperatures have been increasing, as have the frequencies of extreme climatic events (Hughes 2003). The cause is the monotonic increase in emissions of “greenhouse” gases, especially CO2. With knowledge that human activity has been the major contributor to these trends and that their continuation will have dire consequences for life on earth, many world governments have enacted policies to slow or reverse the
13 liberation of CO2. Similarly, longitudinal studies of individual species, habitats and local or regional ecosystems often provide the rationale (and the knowledge) needed to conserve them; or, in the case of pests, weeds or overabundant native species, conversely, the trigger to manage their numbers or impacts. In my own experience in central Australia, the availability of continuous plot-based records on flora and fauna from 1990 persuaded Bush Heritage Australia to purchase two large properties — Ethabuka and Cravens Peak — and to manage them in perpetuity as conservation reserves. Of course, long-term ecological data are not always used wisely by decisionmakers and there is much evidence that they, and associated vested interests, will dither, lie, obfuscate, and disagree when confronted with research findings that conflict with their beliefs or profits (e.g. Banks et al. 2012; McAlpine et al. 2012). But, I digress. This is a topic for another essay! The benefits that can accrue from long-term ecological work are clear, so why isn’t more research of this kind carried out? On the one hand, many ecological questions are short-term and can be answered readily by carrying out one-off sampling or experimentation. On the other, gaining funding and institutional support for long-term research can be challenging. Even when clear objectives and regular milestones are set, it can be years before publishable results are obtained. It may be no accident, for example, that we seldom read about the recovery trajectories of threatened fauna or flora: while regular sampling of threatened taxa may take place, the results usually remain in the grey literature until sufficient recovery has taken place for the results to be acceptable in a peerreviewed scientific journal. This can make life difficult for researchers in institutions that place a premium on consistent publishing outputs. For all these difficulties, there is little doubt that long-term ecological work must remain a critical part of national and international research agendas. This fact was recognized most notably in the USA in 1980 when the National Science Foundation
established the Long-term Ecological Research program. International interest has since seen the formation of a network of long-term research sites in 40 countries on five continents; Jordan and Norway will join this impressive coalition in future (http://www.ilternet.edu). In Australia longitudinal ecological studies have often been carried out in an ad hoc manner and championed by individuals or small groups rather than by institutions, but there are encouraging signs of change. Hero et al. (2010) described a comprehensive and standardized system that is being used to monitor biodiversity at sites in Queensland, while networks of ecological sampling plots, transects and other sampling sites are being coordinated under the Australian government’s Terrestrial Ecosystem Research Network initiative (http:// www.tern.org.au/). Of particular relevance for the arguments presented here is the Long-term Ecological Research Network (LTERN). Established formally in 2012, LTERN integrates several long-established networks of plots and seeks to address key questions associated with the impacts of disturbance to Australian ecosystems (http://tern.org.au/LongTerm-Ecological-Research-Networkpg17872.html). The data returned by these initiatives will allow us to judge our success in managing Australia’s biodiversity and contribute to global conservation goals. RESEARCH IN ARID AUSTRALIA Less ecological research takes place in Australia’s arid and semi-arid regions than in the rest of the country, despite the fact that the dry country covers 70% of the continent. Moreover, very little of this research is long-term (Dickman et al. 2013). This is not surprising: the continental heartland is sparsely inhabited and remote from the major population centres; access to many areas is difficult owing to the lack of tracks and infrastructure; and the climatic conditions are often harsh (Figs 2 and 3). Haythornthwaite (2007) outlined the challenges that are inherent in desert research, but also emphasized the opportunities that can be realized if research is well planned and designed to accommodate the vagaries of the climate.
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Fig. 2. Unexpected heavy rain can fall at any time of year in Australian arid environments and have unfortunate consequences for field researchers who are caught in it. Here, 150 mm of rain fell in two days on Cravens Peak, south-western Queensland, in April 2000. Photo: Bobby Tamayo.
The paucity of ecological desert research is unfortunate for a number of reasons. Most obviously, arid Australia is a biological cornucopia whose riches remain untapped. Its landscapes contain diverse mosaics of habitats, many endemic species, distinctive ecological processes, and pulse-driven ecosystems that are unlike any in the temperate regions (Morton et al. 2011). These features offer excellent opportunities for research. Whereas much early work focused on understanding how species cope physiologically with tough environmental conditions, many studies now describe suites of novel behavioural and ecological traits that allow persistence during periods of flood, heat or prolonged drought. Small mammals, for example, show extraordinary flexibility in social behaviour and diet between population booms and busts, and will travel more than 10 km to access desert areas that have received recent rain (Dickman et al. 2010). Other studies are discovering hosts of new species, quantifying the effects of ‘ecosystem engineers’ such as the Bilby Macrotis lagotis or keystone predators such as
the Brush-tailed Mulgara Dasycercus blythi, or describing rich networks of interactions between pollinators and flowers, predators and prey and parasites and their hosts (see Dickman et al. 2007; Popic and Wardle 2012 for a few of many of the possible examples). In addition to the opportunities for ecological study, another imperative that should drive more research in arid Australia is the fact that the region is a conservation basket case. This is, admittedly, not immediately obvious: only 97 of the 1689 plant and animal species (5.7%) and two of the 56 ecological communities (3.6%) that are listed as threatened under the Commonwealth’s Environment Protection and Biodiversity Conservation (EPBC) Act 1999 are confined to arid Australia (http:// www.environment.gov.au/biodiversity/ threatened/index.html, accessed on 9– 11 June 2012). Against this, however, the region has sustained more extinctions of native mammals (at least 16 of 27 EPBC-listed species and subspecies) than any other since European settlement, and arid regions
are potentially affected by 11 of the 14 key threatening processes that are listed under the EPBC Act as occurring on mainland Australia. These disparate statistics almost certainly indicate that the arid regions remain grossly under-surveyed and that the true conservation status of much of the biota is uncertain. Recent studies of flora in western Queensland support this view, with the recognition that over 60 potentially threatened species have been overlooked in the listing process (Silcock et al. 2011). Surveys of desert fauna similarly are likely to discover some species that were unknown previously in a given region, but will often fail to find others that were expected to be present (e.g., Vanderduys et al. 2011). In addition to the known and listed threats, others abound. Large areas of the semi-arid rangelands continue to be degraded from inappropriate pastoral practices, weeds such as Buffel Grass Cenchrus ciliaris are strangling increasingly large areas, and climate change is likely to affect biodiversity in the dry country severely in the future (Stafford Smith
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Fig. 3. Following heavy rain years, wildfires can burn large areas of vegetation, providing hazards and also opportunities for field researchers. Here, wildfires began from lightning strikes in November 2001 and subsequently burnt over a quarter of a million hectares of spinifex grassland in the north-eastern Simpson Desert, south-western Queensland. Photo: Mike Letnic.
and Cribb 2009). The need for sustained survey and research could not be more acute. The spectre of climate change provides another powerful justification for initiating and expanding desert research, especially long-haul research. Current predictions indicate that mean minimum and annual temperatures will increase, rainfall will decrease markedly in southern arid regions but less so in northern regions, and that extreme temperature and rainfall-drought events will increase in amplitude (Low 2011; Greenville et al. 2012). How will biota fare under these new conditions? There is considerable uncertainty. One possibility is that the boom-bust events that now characterize arid Australian environments will become even more pronounced, triggering
exaggerated pulses and then crashes in primary productivity and in the populations of the many primary and secondary consumers that depend on it. Prolonged population troughs may exacerbate the chances of stochastic extinction at local or even regional scales. Increased frequency and intensity of pulse-dependent processes, especially wildfire, will have additional effects and likely interact with exotic plant and animal species to further change the structure of native ecological communities. Low (2011) has provided a series of predictions for the biota of Queensland, and the picture he paints is a sobering one. Stafford Smith and Cribb (2009), by contrast, point to the resilience of arid Australian environments and suggest that the resourcefulness of their diverse inhabitants can provide secrets for
local survival and even planetary prosperity. How can we unlock these secrets and learn to conserve and manage desert biodiversity in future? It seems to me that we must engage in longitudinal studies that allow us to track shifts in environmental drivers and the organisms that they influence, and to manipulate components of arid systems that allow us to quantify cause and effect relationships. Dickman and Wardle (2012) suggested that we should appeal to personal motivations to get local people involved in these studies, using social networking media and other technologies to encourage this. Here, I argue that long-haul research also will be critically important if we are to succeed in conserving biodiversity in remote environments. There is no (more) time to lose!
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16 ACKNOWLEDGEMENTS I am indebted to my colleagues in the Desert Ecology Research Group, especially Glenda Wardle, Bobby Tamayo, Aaron Greenville, Chin-Liang Beh, Max Tischler and Mike Letnic, for their many contributions to the formulation of the ideas expressed here and for their long-haul collaboration in desert research. I thank Carol McKechnie, Peter and Rosemary Grant, Dan Lunney, Harry Recher and Glenda Wardle for their insightful comments on earlier drafts, the Australian Research Council for provision of grants over many years, and Graham Fulton for the invitation and opportunity to contribute this article. REFERENCES Banks, P., Lunney, D., and Dickman, C., eds, 2012. Science under Siege: zoology under threat. Royal Zoological Society of New South Wales, Mosman, NSW, Australia. Braithwaite, R. W. and Muller, W. J., 1997. Rainfall, groundwater and refuges: predicting extinctions of Australian tropical mammal species. Aust. J. Ecol. 22: 57–67. Dickman, C. R., 2003. Distributional ecology of dasyurid marsupials. Pp. 318–331 in Predators with Pouches: the biology of carnivorous marsupials, ed. by M. E. Jones, C. R. Dickman and M. Archer. CSIRO Publishing, Melbourne, Australia. Dickman, C. R., Greenville, A. C., Beh, C.L., Tamayo, B., and Wardle, G. M., 2010. Social organization and movements of desert rodents during population “booms” and “busts” in central Australia. J. Mammal. 91: 798–810. Dickman, C. R., Lunney, D., and Burgin, S., eds, 2007. Animals of Arid Australia: out on their own? Royal Zoological Society of New South Wales, Mosman, NSW, Australia. Dickman, C. R. and Wardle, G. M., 2012. Monitoring for improved biodiversity conservation in arid Australia. Pp. 157– 164 in Biodiversity Monitoring in Australia, ed. by D. Lindenmayer and P. Gibbons. CSIRO Publishing, Melbourne, Australia. Dickman, C. R., Wardle, G. M., Foulkes, J. N., and de Preu, N., 2013. Desert complex environments. In press in Biodiversity and Environmental Change: Monitoring Challenges and Direction, ed. by D. B. Lindenmayer, E. Burns, N. Thurgate, and A. Lowe. CSIRO Publishing, Melbourne, Australia. Grant, P. R. and Grant, B. R., 2002. Unpredictable evolution in a 30–year study of Darwin’s finches. Sci. 296: 707–711.
Grant, P. R. and Grant, B. R., 2010. Ecological insights into the causes of an adaptive radiation from long-term field studies of Darwin’s finches. Pp. 109–133 in The Ecology of Place, ed. by I. Billick and M. V. Price. University of Chicago Press, Chicago, USA. Greenville, A. C., Wardle, G. M., and Dickman, C. R., 2012. Extreme climatic events drive mammal irruptions: regression analysis of 100–year trends in desert rainfall and temperature. Ecol. & Evol. 2: 2645–2658. Haythornthwaite, A. S., 2007. Postgraduate research in the Simpson Desert: the pitfalls of a PhD. Pp. 76–81 in Animals of Arid Australia: out on their own?, ed. by C. R. Dickman, D. Lunney and S. Burgin. Royal Zoological Society of New South Wales, Mosman, NSW, Australia. Hero, J.-M., Castley, J. G., Malone, M., Lawson, B., and Magnusson, W. E., 2010. Long-term ecological research in Australia: innovative approaches for future benefits. Aust. Zool. 35: 216–228. Hoskin, E. S., 1991. The Birds of Sydney, County of Cumberland, New South Wales 1770–1989. Surrey Beatty & Sons, Chipping Norton, NSW, Australia. Hughes, L., 2003. Climate change and Australia: trends, projections and impacts. Austral Ecol. 28: 423–443. Letnic, M. and Dickman, C. R., 2010. Resource pulses and mammalian dynamics: conceptual models for hummock grasslands and other Australian desert habitats. Biolog. Rev. 85: 501–521. Likens, G. E., ed., 1989. Long-term Studies in Ecology: approaches and alternatives. Springer-Verlag, New York, USA. Lindenmayer, D. B., Likens, G. E., Andersen, A., Bowman, D., Bull, C. M., Burns, E., Dickman, C. R., Hoffmann, A. A., Keith, D. A., Liddell, M. J., Lowe, A. J., Metcalfe, D. J., Phinn, S. R., RussellSmith, J., Thurgate, N., and Wardle, G. M., 2012. Value of long-term ecological studies. Austral Ecol. 37: 745–757. Lomolino, M. V., 2000. A call for a new paradigm of island biogeography. Global Ecol. & Biogeog. 9: 1–6. Low,
T., 2011. Climate Change and Queensland Biodiversity. Department of Environment and Resource Management, Queensland Government, Brisbane, Australia.
McAlpine, C. A., Seabrook, L. M. AdamsHosking, C., Hartley, K. H., and Syktus, J., 2012. Climate change: lessons from Copenhagen and Cancun, and implications for Australia, its regional ecosystems and wildlife. Pp. 1–2 in Wildlife and Climate Change, ed. by D. Lunney and P. Hutchings. Royal Zoological Society of New South Wales, Mosman, NSW, Australia.
Morton, S. R., Stafford Smith, D. M., Dickman, C. R., Dunkerley, D. L., Friedel, M. H., McAllister, R. R. J., Reid, J. R. W., Roshier, D. A., Smith, M. A., Walsh, F. J., Wardle, G. M., Watson, I. W., and Westoby, M., 2011. A fresh framework for the ecology of arid Australia. J. Arid Env. 75: 313–329. Pianka, E. R., 1986. Ecology and Natural History of Desert Lizards. Princeton University Press, New Jersey, USA. Pianka, E. R. and Goodyear, S. E., 2012. Lizard responses to wildfire in arid interior Australia: long-term experimental data and commonalities with other studies. Austral Ecol. 37: 1–11. Pimm, S. L. and Redfearn, A., 1988. The variability of population densities. Nat. 334: 613–614. Popic, T. J. and Wardle, G. M., 2012. Extremes: understanding flower-visitor interactions in a changing climate. Pp. 99–106 in Wildlife and Climate Change, ed. by D. Lunney and P. Hutchings. Royal Zoological Society of New South Wales, Mosman, NSW, Australia. Recher, H. F. and Lim, L., 1990. A review of current ideas of the extinction, conservation and management of Australia’s terrestrial vertebrate fauna. Proc. Ecolog. Soc. Aust. 16: 287–301. Silcock, J. L., Fensham, R. J., and Martin, T. G., 2011. Assessing rarity and threat in an arid-zone flora. Aust. J. Bot. 59: 336–350. Silvertown, J., Poulton, P., Johnston, E., Edwards, G., Heard, M., and Biss, P. M., 2006. The Park Grass Experiment 1856–2006: its contribution to ecology. J. Ecol. 94: 801–814. Stafford Smith, M. and Cribb, J., 2009. Dry Times: blueprint for a red land. CSIRO Publishing, Melbourne, Australia. Stenseth, N. C., Viljugrein, H., Saitoh, T., Hansen, T. F., Kittilsen, M. O., Bølviken, E., and Glöckner, F., 2003. Seasonality, density dependence, and population cycles in Hokkaido voles. Proc. Nat. Acad. Sci. USA 100: 11478–11483. van Andel, J. and Aronson, J., eds, 2006. Restoration Ecology. Blackwell, Oxford, UK. Vanderduys, E., Hines, H., Gynther, I., Kutt, A., and Absolon, M., 2011. Lerista desertorum — a new skink species for Queensland with notes on other significant herpetofauna records from western Queensland. Aust. Zool. 35: 622–626. Williams, N. S. G., McDonnell, M. J., Phelan, G. K., Keim, L. D., and van der Ree, R., 2006. Range expansion due to urbanization: increased food resources attract grey-headed flying-foxes (Pteropus poliocephalus) to Melbourne. Austral Ecol. 31: 190–198.
Forum Essay Woinarski, J. C. Z., Legge, S., Fitzsimons, J. A., Traill, B. J., Burbidge, A. A., Fisher, A., Firth, R. S. C., Gordon, I. J., Griffiths, A. D., Johnson, C. N., McKenzie, N. L., Palmer, C., Radford, I., Rankmore, B., Ritchie, E. G., Ward, S., and Ziembicki, M., 2011. The disappearing mammal fauna of northern Australia: context, cause, and response. Cons. Letters 4: 192–201. Zub, K., Jêdrzejewska, B., Jêdrzejewski, W., and Barton, K. A., 2012. Cyclic voles and shrews and non-cyclic mice in a marginal grassland within European temperate forest. Acta Theriologica 57: 205–216.
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Biography
CHRIS Dickman has long been
fascinated by patterns in the distribution of living things, and by factors such as invasive pest species that affect biological diversity. His current work focuses on biota in arid environments and on a range of other projects in applied conservation and management. An ARC Professorial Fellow, Chris has been a prolific trainer of postgraduates, supervising 41 Honours, 31 Masters and 51 PhD students over the last 25 years. He
has written or edited 20 books and monographs and authored a further 290 journal articles and book chapters. He is the recipient of several awards, including the Troughton Medal from the Australian Mammal Society, the Merriam Medal from the American Society of Mammalogists, and the Whitley Medal for the best natural history book (A Fragile Balance) in 2008. He was the inaugural chair of the NSW Government Scientific Committee from 1996–2002.
DISCOUNT OFFER TTO O PCB SUBSCRIBERS A 50% discount offer to all subscribers, associates and authors of Pacific Conservation Biology is available on books published by Surrey Beatty & Sons until 31 July, 2013. A booklist is enclosed in this issue. Please indicate this offer when you place an order. Fees apply for postage and handling.
