Hydrologic landscape regionalisation using deductive classification and random forests

Landscape classification and hydrological regionalisation studies are being increasingly used in ecohydrology to aid in the management and research of aquatic resources. We present a methodology for classifying hydrologic landscapes based on spatial environmental variables by employing non-parametric statistics and hybrid image classification. Our approach differed from previous classifications which have required the use of an a priori spatial unit (e.g. a catchment) which necessarily results in the loss of variability that is known to exist within those units. The use of a simple statistical approach to identify an appropriate number of classes eliminated the need for large amounts of post-hoc testing with different number of groups, or the selection and justification of an arbitrary number. Using statistical clustering, we identified 23 distinct groups within our training dataset. The use of a hybrid classification employing random forests extended this statistical clustering to an area of approximately 228,000 km2 of south-eastern Australia without the need to rely on catchments, landscape units or stream sections. This extension resulted in a highly accurate regionalisation at both 30-m and 2.5-km resolution, and a less-accurate 10-km classification that would be more appropriate for use at a continental scale. A smaller case study, of an area covering 27,000 km2, demonstrated that the method preserved the intra- and inter-catchment variability that is known to exist in local hydrology, based on previous research. Preliminary analysis linking the regionalisation to streamflow indices is promising suggesting that the method could be used to predict streamflow behaviour in ungauged catchments. Our work therefore simplifies current classification frameworks that are becoming more popular in ecohydrology, while better retaining small-scale variability in hydrology, thus enabling future attempts to explain and visualise broad-scale hydrologic trends at the scale of catchments and continents.

A decade of change in Australia’s DBA landscape

Purpose – The purpose of this paper is to examine the dynamics of the Doctorate of Business Administration (DBA) in Australia through the lens of a changing higher education landscape. The paper reflects on issues raised in a previous analysis of DBA programmes undertaken a decade ago, and highlights persistent challenges and emerging opportunities for professional Doctorate programmes in the Australian context.Design/methodology/approach – Interviews were undertaken with higher degree research directors, deans of graduate schools, and DBA programme directors from all 18 Australian institutions offering the DBA in 2013. Quantitative data on enrolments, accreditation requirements, course structures; and demographics are contextualised within a qualitative view of programme purposes, student and institutional motivations, rationales and concerns. Particular focus is given to perceptions of the difference between traditional research doctorates (PhDs) and professional doctorates, especially the DBA.Findings – In the decade from 2003 to 2013 DBA enrolments are down but enquiries are up, indicating unmet demand. There is a shift in the players, with some smaller, regional universities dramatically increasing their enrolments, and larger, traditional institutions exiting the space altogether. Significant changes in accreditation criteria have generated a perceptual shift: where DBAs previously suffered from “academic snobbery” regarding their legitimacy, this perception is being challenged by standards which require DBA equivalence with a PhD. This shift in standards has also created some confusion amongst supervisors and candidates.Originality/value – There is limited research into the DBA award or its candidates, and academic literature is generally silent on DBA supervision. This piece of research, one of very few that specifically examine the DBA, reflects on the past decade, analyses the present context and identifies emerging issues for the delivery of DBA programmes in Australia.

Does fire influence the landscape-scale distribution of an invasive mesopredator?

Predation and fire shape the structure and function of ecosystems globally. However, studies exploring interactions between these two processes are rare, especially at large spatial scales. This knowledge gap is significant not only for ecological theory, but also in an applied context, because it limits the ability of landscape managers to predict the outcomes of manipulating fire and predators. We examined the influence of fire on the occurrence of an introduced and widespread mesopredator, the red fox (Vulpes vulpes), in semi-arid Australia. We used two extensive and complimentary datasets collected at two spatial scales. At the landscape-scale, we surveyed red foxes using sand-plots within 28 study landscapes - which incorporated variation in the diversity and proportional extent of fire-age classes - located across a 104 000 km2 study area. At the site-scale, we surveyed red foxes using camera traps at 108 sites stratified along a century-long post-fire chronosequence (0-105 years) within a 6630 km2 study area. Red foxes were widespread both at the landscape and site-scale. Fire did not influence fox distribution at either spatial scale, nor did other environmental variables that we measured. Our results show that red foxes exploit a broad range of environmental conditions within semi-arid Australia. The presence of red foxes throughout much of the landscape is likely to have significant implications for native fauna, particularly in recently burnt habitats where reduced cover may increase prey species' predation risk.

Granitic coastal geomorphology: Applying integrated terrestrial and bathymetric LiDAR with multibeam sonar to examine coastal landscape evolution

Coasts composed of resistant lithologies such as granite are generally highly resistant to erosion. They tend to evolve over multiple sea level cycles with highstands acting to remove subaerially weathered material. This often results in a landscape dominated by plunging cliffs with shore platforms rarely occurring. The long-term evolution of these landforms means that throughout the Quaternary these coasts have been variably exposed to different sea level elevations which means erosion may have been concentrated at different elevations from today. Investigations of the submarine landscape of granitic coasts have however been hindered by an inability to accurately image the nearshore morphology. Only with the advent of multibeam sonar and aerial laser surveying can topographic data now be seamlessly collected from above and below sea level. This study tests the utility of these techniques and finds that very accurate measurements can be made of the nearshore thereby allowing researchers to study the submarine profile with the same accuracy as the subaerial profile. From a combination of terrestrial and marine LiDAR data with multibeam sonar data, it is found that the morphology of granite domes is virtually unaffected by erosion at sea level. It appears that evolution of these landscapes on the coast is a very slow process with modern sea level acting only to remove subaerially weathered debris. The size and orientation of the joints determines the erosional potential of the granite. Where joints are densely spaced (<2 m apart) or the bedrock is highly weathered can semi-horizontal surfaces form.

Building Nature’s Safety Net 2014 : A decade of protected area achievements in Australia

The single most important asset for the conservation of Australia’s unique and globally significant biodiversity is the National Reserve System, a mosaic of over 10,000 discrete protected areas on land on all tenures: government, Indigenous and private,including on-farm covenants, as well as state, territory and Commonwealth marine parks and reserves.THE NATIONAL RESERVE SYSTEMIn this report, we cover major National Reserve System initiatives that have occurred in the period 2002 to the present and highlight issues affecting progress toward agreed national objectives. We define a minimum standard for the National Reserve System to comprehensively, adequately and representatively protect Australia’s ecosystem and species diversity on sea and land. Using government protected area, species and other relevant spatial data, we quantify gaps: those areas needing to move from the current National Reserve System to one which meets this standard. We also provide new estimates of financial investments in protected areas and of the benefits that protected areas secure for society. Protected areas primarily serve to secure Australia’s native plants and animals against extinction, and to promote their recovery.BENEFITSProtected areas also secure ecosystem services that provide economic benefits forhuman communities including water, soil and beneficial species conservation, climatemoderation, social, cultural and health benefits. On land, we estimate these benefitsare worth over $38 billion a year, by applying data collated by the Ecosystem ServicesPartnership. A much larger figure is estimated to have been secured by marineprotected areas in the form of moderation of climate and impact of extreme eventsby reef and mangrove ecosystems. While these estimates have not been verified bystudies specific to Australia, they are indicative of a very large economic contributionof protected areas. Visitors to national parks and nature reserves spend over $23.6 billion a year in Australia, generating tax revenue for state and territory governments of $2.36 billion a year. All these economic benefits taken together greatly exceed the aggregate annual protected area expansion and management spending by all Australian governments, estimated to be ~$1.28 billion a year. It is clear that Australian society is benefiting far greater than its governments’ investment into strategic growth and maintenance of the National Reserve System.Government investment and policy settings play a leading role in strategic growth of the National Reserve System in Australia, and provide a critical stimulus fornon-government investment. Unprecedented expansion of the National Reserve System followed an historic boost in Australian Government funding under Caring for Our Country 2008–2013. This expansion was highly economical for the Australian Government, costing an average of only $44.40 per hectare to buy and protect land forever. State governments have contributed about six times this amount toward the expansion of the National Reserve System, after including in-perpetuity protected area management costs. The growth of Indigenous Protected Areas by the Australian Government has cost ~$26 per hectare on average, including management costs capitalised in-perpetuity, while also delivering Indigenous social and economic outcomes. The aggregate annual investment by all Australian governments has been ~$72.6 million per year on protected area growth and ~$1.21 billion per year on recurrent management costs. For the first time in almost two decades, however, the Australian Government’s National Reserve System Program, comprising a specialist administrative unit and funding allocation, was terminated in late 2012. This program was fundamental in driving significant strategic growth in Australia’s protected area estate. It is highly unlikely that Australia can achieve its long-standing commitments to an ecologically representative National Reserve System, and prevent major biodiversity loss, without this dedicated funding pool. The Australian Government has budgeted ~$400 million per year over the next five years (2013-2018) under the National Landcare and related programs. This funding program should give high priority to delivery of national protected area commitments by providing a distinct National Reserve System funding allocation. Under the Convention on Biological Diversity (CBD), Australia has committed to bringing at least 17 percent of terrestrial and at least 10 per cent of marine areas into ecologically representative, well-connected systems of protected areas by 2020 (Aichi Target 11).BIODIVERSITY CONSERVATIONAustralia also has an agreed intergovernmental Strategy for developing a comprehensive, adequate and representative National Reserve System on land andsea that, if implemented, would deliver on this CBD target. Due to dramatic recent growth, the National Reserve System covers 16.5 per cent of Australia’s land area, with highly protected areas, such as national parks, covering 8.3 per cent. The marine National Reserve System extends over one-third of Australian waters with highly protected areas such as marine national parks, no-take or green zones covering 13.5 per cent. Growth has been uneven however, and the National Reserve System is still far from meeting Aichi Target 11, which requires that it also be ecologically representative and well-connected. On land, 1,655 of 5,815 ecosystems and habitats for 138 of 1,613 threatened species remain unprotected. Nonetheless, 436 terrestrial ecosystems and 176 threatened terrestrial species attained minimum standards of protection due to growth of the National Reserve System on land between 2002 and 2012. The gap for ecosystem protection on land – the area needed to bring all ecosystems to the minimum standard of protection – closed by a very substantial 20 million hectares (from 77 down to 57 million hectares) between 2002 and 2012, not including threatened species protection gaps. Threatened species attaining a minimum standard for habitat protection increased from 27 per cent to 38 per cent over the decade 2002–2012. A low proportion of critically endangered species meeting the standard (29 per cent) and the high proportion with no protection at all (20 per cent) are cause for concern, but one which should be relatively easy to amend, as the distributions of these species tend to be small and localised. Protected area connectivity has increased modestly for terrestrial protected areas in terms of the median distance between neighbouring protected areas, but this progress has been undermined by increasing land use intensity in landscapes between protected areas.A comprehensive, adequate and representative marine reserve system, which meetsa standard of 15 per cent of each of 2,420 marine ecosystems and 30 per cent of thehabitats of each of 177 marine species of national environmental significance, wouldrequire expansion of marine national parks, no-take or green zones up to nearly 30per cent of state and Australian waters, not substantially different in overall extentfrom that of the current marine reserve system, but different in configuration.Protection of climate change refugia, connectivity and special places for biodiversityis still low and requires high priority attention. FINANCING TO FILL GAPS AND MEET COMMITMENTSIf the ‘comprehensiveness’ and ‘representativeness’ targets in the agreed terrestrial National Reserve System Strategy were met by 2020, Australia would be likely to have met the ‘ecologically representative’ requirement of Aichi Target 11. This would requireexpanding the terrestrial reserve system by at least 25 million hectares. Considering that the terrestrial ecosystem protection gap has closed by 20 million hectares over the past decade, this required expansion would be feasible with a major boost in investment and focus on long-standing priorities. A realistic mix of purchases, Indigenous Protected Areas and private land covenants would require an Australian Government National Reserve System investment of ~$170 million per year over the five years to 2020, representing ~42 per cent of the $400 million per year which the Australian Government has budgeted for landcare and conservation over the next five years. State, territory and local governments, private and Indigenous partners wouldlikewise need to boost financial commitments to both expand and maintain newprotected areas to meet the agreed National Reserve System strategic objectives.The total cost of Australia achieving a comprehensive, adequate and representativemarine reserve system that would satisfy Aichi Target 11 is an estimated $247 million.

The influence of non-climate predictors at local and landscape resolutions depends on the autecology of the species

Species distribution models have come under criticism for being too simplistic for making robust future forecasts, partly because they assume that climate is the main determinant of geographical range at large spatial extents and coarse resolutions, with non-climate predictors being important only at finer scales. We suggest that this paradigm might be obscured by species movement patterns. To explore this we used contrasting kangaroo (family Macropodidae) case studies: two species with relatively small, stable home ranges (Macropus giganteus and M.robustus) and three species with more extensive, adaptive ranging behaviour (M.antilopinus, M.fuliginosus and M.rufus). We predicted that non-climate predictors will be most influential to model fit and predictive performance at local spatial resolution for the former species and at landscape resolution for the latter species. We compared residuals autocovariate - boosted regression tree (RAC-BRT) model statistics with and without species-specific non-climate predictors (habitat, soil, fire, water and topography), at local- and landscape-level spatial resolutions (5 and 50km). As predicted, the influence of non-climate predictors on model fit and predictive performance (compared with climate-only models) was greater at 50 compared with 5km resolution for M.rufus and M.fuliginosus and the opposite trend was observed for M.giganteus. The results for M.robustus and M.antilopinus were inconclusive. Also notable was the difference in inter-scale importance of climate predictors in the presence of non-climate predictors. In conclusion, differences in autecology, particularly relating to space use, may contribute to the importance of non-climate predictors at a given scale, not model scale per se. Further exploration of this concept across a range of species is encouraged and findings may contribute to more effective conservation and management of species at ecologically meaningful scales. © 2014 Ecological Society of Australia.

Plantations, not farmlands, cause biotic homogenisation of ground-active beetles in South-Eastern Australia

Following landscape change, species invasions and extinctions may lead to biotic homogenisation, resulting in increased taxonomic and functional similarity between previously distinct biotas. Biotic homogenisation is more likely to occur in landscapes where the matrix contrasts strongly with native vegetation patches. To test this, we examined the distribution of ground-active beetles in a landscape of remnant Eucalyptus open woodland patches where large areas of lower contrast matrix (farmland) are being transformed to high-contrast pine plantations in south-eastern Australia. We sampled beetles from 30 sites including six replicates of five categories; (1) remnants adjacent to farmland, (2) remnants adjacent to plantation, (3) farmland, (4) plantation, and, (5) remnants between pine plantation and farmland. Community composition in the pine matrix was similar to native patches embedded in pine (ANOSIM, Global R=. 0.49, P<. 0.000), which we suggest is due to biotic homogenisation. Remnant patches with edges of both farmland and pine plantation did not represent an intermediate community composition between patches surrounded by either matrix type, but rather a unique habitat with unique species. Farmland supported the greatest number of individuals (. F=. 9.049, df. =. 25, P<. 0.000) and species (. F=. 5.875, df. =. 25, P=. 0.002), even compared to native remnant patches. Our results suggest that matrix transformations can reduce species richness and homogenise within-patch populations. This may increase the risk of species declines in fragmented landscapes where plantations are not only replacing native vegetation patches, but also other matrix types that may better support biodiversity. Our findings are particularly concerning given expanding plantation establishment worldwide.

What determines habitat quality for a declining woodland bird in a fragmented environment: the grey-crowned babbler pomatostomus temporalis in South-Eastern Australia?

Understanding what constitutes high quality habitat is crucial for the conservation of species, especially those threatened with extinction. Habitat quality frequently is inferred by comparing the attributes of sites where a species is present with those where it is absent. However, species presence may not always indicate high quality habitat. Demographic parameters are likely to provide a more biologically relevant measure of quality, including a species' ability to successfully reproduce. We examined factors believed to influence territory quality for the grey-crowned babbler (Pomatostomus temporalis), a cooperatively breeding woodland bird that has experienced major range contraction and population decline in south-eastern Australia. Across three broad regions, we identified active territories and determined the presence of fledglings and the size of family groups, as surrogates of territory quality. These measures were modelled in relation to habitat attributes within territories, the extent of surrounding wooded vegetation, isolation from neighbouring groups, and the size of the neighbourhood population. Fledgling presence was strongly positively associated with group size, indicating that helpers enhance breeding success. Surprisingly, no other territory or landscape-scale variables predicted territory quality, as inferred from either breeding success or group size. Relationships between group size and environmental variables may be obscured by longer-term dynamics in group size. Variation in biotic interactions, notably competition from the noisy miner (Manorina melanocephala), also may contribute. Conservation actions that enhance the number and size of family groups will contribute towards reversing declines of this species. Despite associated challenges, demographic studies have potential to identify mechanistic processes that underpin population performance; critical knowledge for effective conservation management.

Cyber security and protection of ICS systems: An australian example

Many aspects of our modern society now have either a direct or implicit dependence upon information technology. As such, a compromise of the availability or integrity in relation to these systems (which may encompass such diverse domains as banking, government, health care, and law enforcement) could have dramatic consequences from a societal perspective. These key systems are often referred to as critical infrastructure. Critical infrastructure can consist of corporate information systems or systems that control key industrial processes; these specific systems are referred to as ICS (Industry Control Systems) systems. ICS systems have devolved since the 1960s from standalone systems to networked architectures that communicate across large distances, utilise wireless network and can be controlled via the Internet. ICS systems form part of many countries’ key critical infrastructure, including Australia. They are used to remotely monitor and control the delivery of essential services and products, such as electricity, gas, water, waste treatment and transport systems. The need for security measures within these systems was not anticipated in the early development stages as they were designed to be closed systems and not open systems to be accessible via the Internet. We are also seeing these ICS and their supporting systems being integrated into organisational corporate systems.

Towards a theory of landscape iconoclasm

The destruction of Indigenous rock art sites in the Pilbara district in Western Australia has become a natural sight within the mining landscape of the area. Whilst much of the destruction is explained as acts of vandalism and as a result of the industrial activities that are propelling the Australian economy, I claim that a new theory of iconoclasm is needed to explain fully this disastrous example of heritage conservation. Henceforth, in order to explain the destruction of the Murujuga/Burrup Peninsula petroglyphs, the largest archaeological site in the world, this paper develops the theory of landscape iconoclasm. This theory states that the destruction of Indigenous landscapes can be compared to the destruction of religious images, by analysing the inherent symbolic functions of iconoclasm, together with those of heritage, the better to elucidate the state of affairs in the Murujuga/Burrup Peninsula. Furthermore, by drawing from Aboriginal mythology and art-historical and anthropological theories, the theory of landscape iconoclasm is able to explain the destruction of archaeological sites within a framework that falls outside prevalent discourses of heritage.

Home range, habitat use and movements by the little raven (Corvus mellori) in a coastal peri-urban landscape

Context In peri-urban environments, high availability of anthropogenic resources may result in relatively high abundances of some species, with potentially negative implications for other native biota. Effective management of such impacts requires understanding of the spatial ecology of problem species. However, home range and habitat use have not been described for the little raven (Corvus mellori), a superabundant native predator that occurs in urban and natural habitats, including those where threatened shorebirds breed. Aims The aim of this study was to provide basic information on little raven home range, habitat use and movements in a coastal peri-urban landscape. Methods Between October 2011 and January 2012 we radio-tracked 20 little ravens captured in a coastal wetland (near Melbourne, Australia). Key results Little ravens were highly mobile, moving up to 9.9km in an hour (median≤2km), and had large ranges: Minimum Convex Polygons were 1664-9989ha (median≤3362ha). Although most birds used both anthropogenic and natural habitats, some birds strongly selected for coastal wetland habitat. Birds used multiple roosts during the study period, most of which occurred in grassland (58.7%) or urban (22.3%) areas. Movement of up to 8.3km (median≤2.2km) between roosts during the night was also detected. Conclusions Ravens were highly mobile and used large home ranges and a variety of habitats, with habitat preferences varying between birds. Implications Considering the large home ranges and inter-individual variation in habitat preferences of little raven populations, localised management to reduce their impacts on breeding shorebirds is unlikely to be successful. Journal compilation

Artificial water points facilitate the spread of an invasive vertebrate in arid Australia

Summary: The spread of invasive species after their initial introduction is often facilitated by human actions. In some cases, invaders only become established in habitats where dominant native species have been displaced as a result of human actions or where humans inadvertently provide essential resources such as food, water or shelter. We investigated if dams that provide water for livestock have facilitated the cane toad's (Rhinella marina) invasion of a hot semi-arid landscape by providing toads with a resource subsidy and hence refuge from extreme heat and aridity. To determine the relationship between the presence of surface water and habitat occupancy by toads, we surveyed natural and artificial water features for cane toads during the annual dry season. We used radiotracking and acoustic tags to determine whether movement patterns and shelter use of cane toads were focussed around dams. To determine whether dams provide toads with refuge from extreme heat and aridity, we deployed plaster models with internal thermometers to estimate ambient temperatures and toad desiccation rates in shelter sites. To determine whether dams alleviate the stress experienced by toads, we measured plasma corticosterone levels of toads that sheltered in and away from dams. Toads were present in sites with standing water and absent from waterless sites. Most radiotracked toads sheltered within 1 m of water. Toad movements were focussed around water. Toads tracked with passive acoustic telemetry over a 6-month dry season were highly resident at dams. Plaster models placed in toad shelter sites away from the water lost 27% more mass and experienced higher temperatures than models placed near the water's edge. Toads that sheltered in terrestrial shelters exhibited higher plasma corticosterone levels compared to toads that sheltered near dams. Dams provide toads with refuge habitats where they are less at risk from overheating and dehydration. Synthesis and applications. Artificial water points can facilitate biological invasions in arid regions by providing a resource subsidy for water-dependent invasive species. Our study suggests that there is scope to control populations of water-dependent invasive vertebrates in arid regions by restricting their access to artificial water points.

Effects of multiple disturbance processes on arboreal vertebrates in Eastern Australia: implications for management

Habitat loss and invasive predators increasingly threaten global biodiversity. Here we use a landscape-scale experimental approach to explore the individual and synergistic effects of logging and an invasive predator, the red fox Vulpes vulpes on two common native arboreal vertebrates (a predator and prey species) in south-eastern Australia. We used site occupancy methods to evaluate different models evaluating the effects of site specific forest logging disturbance, lethal fox baiting and forest structural elements for explaining variation in site occupancy of a large monitor lizard Varanus varius, and a marsupial prey, the common ringtail possum Pseudocheirus peregrinus across a complex forest landscape. Site occupancy of ringtail possum was influenced by habitat resources and the structural complexity of forest, which indirectly mediated predation risk. Presence of fox baiting had no direct effect on the ringtail site occupancy. In contrast, access to prey resources and fox baiting appeared to best explain site occupancy variation in monitor lizards across the landscape. While these species are affected primarily by separate disturbances, synergistic interactions between the processes may intensify their effects. Our results demonstrate that species susceptibility to disturbance processes are highly idiosyncratic. This approach makes efficient use of integrated modelling to aid conservation management at both local and landscape levels.

Effects of the fire regime on mammal occurrence after wildfire: site effects vs landscape context in fire-prone forests

Wildfires have major impacts on ecosystems globally. Fire regimes (including fire frequency, intensity, season and type of fire) influence the status of species by altering habitat suitability at the site scale, and by creating heterogeneity at the landscape scale. The relative effects of site and landscape-scale fire attributes on animal species are rarely examined together. Such knowledge is important, given that fire regimes are sensitive to changing land management practices; and that fires are predicted to become larger and more frequent in some regions as a result of climate change. Here, we tested the relative influence of elements of the fire regime (fire severity, fire history) at the site-scale, and the landscape context (extent of surrounding unburnt forest, fire heterogeneity) on the occurrence of native terrestrial mammals after severe wildfire in south-eastern Australia. We conducted surveys by using automatically triggered, infrared cameras at 80 sites in fire-prone eucalypt forests, 2-3. years post-wildfire. Thirteen native mammal species were recorded, eight of which were detected with sufficient frequency for analysis. Most species were widespread (35-90% of sites) and recorded in all fire severity classes. Fire effects at the site-level were more influential than landscape context effects arising from heterogeneity in the fire regime (e.g. extent of surrounding unburnt forest). Fire severity was the most influential of the fire-regime elements investigated, but it affected different species in different ways. This study highlights three main points relevant to conservation of terrestrial mammals after wildfire. First, spatial variation in fire severity associated with wildfire (ranging from unburned to severely burned stands) is an important contributor to the post-fire status of species. Second, post-fire environmental conditions are significant: here, rapid regeneration of vegetation following drought-breaking rains greatly influenced the suitability of post-fire habitats. Third, it is valuable to consider the effects of the fire regime at multiple scales, including both the site (forest stand) and its landscape context. Insights from short-term surveys, such as this, will be enhanced by complementary longitudinal studies, especially where they encompass environmental variation through the post-fire succession.