Population genetic analysis reveals a long-term decline of a threatened endemic Australian marsupial
- Authors: Hansen, Birgita , Harley, Daniel , Lindenmayer, David , Taylor, Andrea
- Date: 2009
- Type: Text , Journal article
- Relation: Molecular Ecology Vol. 18, no. 16 (2009), p. 3346-3362
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- Description: Since European colonization, Leadbeater's possum (Gymnobelideus leadbeateri) has declined across its range to the point where it is now only patchily distributed within the montane ash forests of the Central Highlands of Victoria. The loss of large hollow-bearing trees coupled with inadequate recruitment of mature ash forest has been predicted to result in a reduction in population size of up to 90% by 2020. Furthermore, bioclimatic analyses have suggested additional reductions in the species' distribution under a variety of climate change scenarios. Using a panel of 15 highly resolving microsatellite markers and mitochondrial control region sequence data, we infer past and present gene flow. Populations in the northern part of the core range were highly admixed, and showed no signs of either current or historical barriers to gene flow. A marginal, isolated and inbred population at Yellingbo was highly genetically differentiated, both in terms of current and historic genetic structure. Sequence data confirmed the conclusions from earlier genetic simulation studies that the Yellingbo population has been isolated from the rest of the species range since before European-induced changes to the montane landscape, and formed part of a larger genetic unit that is now otherwise extinct. Historic loss of maternal lineages in the Central Highlands of Victoria was detected despite signals of immigration, indicating population declines that most probably coincided with changes in climate at the end of the Pleistocene. Given ongoing habitat loss and the recent (February 2009) wildfire in the Central Highlands, we forecast (potentially extensive) demographic declines, in line with predicted range reductions under climate change scenarios. © 2009 Blackwell Publishing Ltd.
Birds as surrogates for mammals and reptiles: Are patterns of cross-taxonomic associations stable over time in a human-modified landscape?
- Authors: Yong, Ding , Barton, Philip , Okada, Sachiko , Crane, Mason , Lindenmayer, David
- Date: 2016
- Type: Text , Journal article
- Relation: Ecological Indicators Vol. 69, no. (2016), p. 152-164
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- Description: Cross-taxonomic surrogates can be feasible alternatives to direct measurements of biodiversity in conservation if validated with robust data and used with explicit goals. However, few studies of cross-taxonomic surrogates have examined how temporal changes in composition or richness in one taxon can drive variation in concordant patterns of diversity in another taxon, particularly in a dynamic and heavily modified landscape. We examined this problem by assessing changes in cross-taxonomic associations over time between the surrogate (birds) and target vertebrate taxa (mammals, reptiles) that demand high sampling effort, in a heterogeneous mosaic landscape comprising pine monoculture, eucalypt woodland remnants and agricultural land. Focussing on four study years (1999, 2001, 2011, 2013) from a dataset collected over 15 years, we: (1) investigated temporal changes in cross-taxonomic congruency among three animal taxa (2) explored how temporal variation in composition and species richness of each taxon might account for variation in cross-taxonomic congruency, and (3) identified habitat structural variables that are strongly correlated with species composition of each taxon. We found the strength of cross-taxonomic congruency varied between taxa in response to both landscape context and over time. Among the three taxa, overall correlations were weak but were consistently positive and strongest between birds and mammals, while correlations involving reptiles were usually weak and negative. We also found that stronger species richness and composition correlations between birds and mammals were not only more prevalent in woodland remnants in the agricultural matrix, but they also increased in strength over time. Temporal shifts in species composition differed in rate and extent among the taxa even though these shifts were significant over time, while important habitat structural correlates were seldom shared across taxa. Our study highlights the role of the landscape matrix and time in shaping animal communities and the resulting cross-taxonomic associations in the woodland remnants, especially after a major perturbation event (i.e. plantation establishment). In such dynamic landscapes, differing and taxon-specific shifts in species diversity over time can influence the strength, direction and consistency of cross-taxonomic correlations, therefore posing a 'temporal' problem for the use of surrogates like birds in monitoring and assessment of biodiversity, and conservation management practices in general. © 2016 Elsevier Ltd. All rights reserved.
Do temporal changes in vegetation structure additional to time since fire predict changes in bird occurrence?
- Authors: Lindenmayer, David , Candy, Steven , MacGregor, Christopher , Banks, Sam , Barton, Philip
- Date: 2016
- Type: Text , Journal article
- Relation: Ecological Applications Vol. 26, no. 7 (2016), p. 2267-2279
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- Description: Fire is a major ecological process in ecosystems globally. Its impacts on fauna can be both direct (e.g., mortality) and indirect (e.g., altered habitat), resulting in population recovery being driven by several possible mechanisms. Separating direct from indirect impacts of fire on faunal population recovery can be valuable in guiding management of biodiversity in fire-prone environments. However, resolving the influence of direct and indirect processes remains a key challenge because many processes affecting fauna can change concomitantly with time since fire. We explore the mechanisms influencing bird response to fire by posing the question, can temporal changes in vegetation structure predict changes in bird occurrence on sites, and can these be separated from other temporal changes using the surrogate of time since fire? We conducted a 12-yr study of bird and vegetation responses to fire at 124 sites across six vegetation classes in Booderee National Park, Australia. Approximately half of these sites, established in 2002, were burned by a large (>3000 ha) wildfire in 2003. To disentangle collinear effects of temporal changes in vegetation and direct demographic effects on population recovery that are subsumed by time since fire, we incorporated both longitudinal and cross-sectional vegetation effects in addition to time since fire within logistic structural equation models. We identified temporal changes in vegetation structure and richness of plant and bird species that characterized burned and unburned sites in all vegetation classes. For nine bird species, a significant component of the year trend was driven by temporal trends in one of three vegetation variables (number of understory or midstory plant species, or midstory cover). By contrast, we could not separate temporal effects between time since fire and vegetation attributes for bird species richness, reporting rate, and the occurrence of 11 other bird species. Our findings help identify species for which indirect effects of vegetation dominate recovery and thus may benefit from vegetation management where conservation actions are required and, conversely, those species for which direct effects of time since fire drive recovery, where simply leaving a system to recover following the last disturbance will be sufficient. © 2016 by the Ecological Society of America.
Effects of environmental variation and livestock grazing on ant community structure in temperate eucalypt woodlands
- Authors: Barton, Philip , Sato, Chloe , Kay, Geoffrey , Florance, Daniel , Lindenmayer, David
- Date: 2016
- Type: Text , Journal article
- Relation: Insect Conservation and Diversity Vol. 9, no. 2 (2016), p. 124-134
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- Description: Grazing by livestock is a major ecological disturbance, with potential effects on vegetation, soil, and insect fauna. Ants are a diverse and functionally important insect group with many associations with the ground layer, yet recent global syntheses question the importance of grazing effects on ant communities relative to vegetation or soil. We examined the effects of vegetation, soil and grazing on the whole ant community, ant functional groups, and abundant species in temperate eucalypt woodlands, southeastern Australia. We found limited influence of grazing on our vegetation and soil measures, except for a positive association between grazing and exotic perennial grass cover. We also found that exotic grass cover had a negative effect on overall ant abundance and richness, but not functional groups or individual species. Soil C:N ratio had a positive effect on the subdominant Camponotini, and leaf litter cover had a positive effect on the abundance of cryptic species. Partial Mantel tests revealed an effect of both environmental and grazing measures on ant assemblage composition, but constrained ordination showed that leaf litter cover, grass biomass, and native and exotic perennial grass cover had stronger correlations with ant community structure than grazing. Our study shows that both environmental variation and grazing play a role in driving ant community structure, but that key environmental variables such as grass biomass and leaf litter cover are particularly important in temperate eucalypt woodlands. Monitoring of ant communities to measure the benefits of changed grazing regimes for biodiversity should consider contemporary grazing pressure as well as the underlying effects of variation in plants and soils. © 2016 The Royal Entomological Society.
Evaluating the effectiveness of overstory cover as a surrogate for bird community diversity and population trends
- Authors: Pierson, Jennifer , Mortelliti, Alessio , Barton, Philip , Lane, Peter , Lindenmayer, David
- Date: 2016
- Type: Text , Journal article
- Relation: Ecological Indicators Vol. 61, no. (2016), p. 790-798
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- Description: Landscape features are often used as surrogates for biodiversity. While landscape features may perform well as surrogates for coarse metrics of biodiversity such as species richness, their value for monitoring population trends in individual species is virtually unexplored. We compared the performance of a proposed habitat surrogate for birds, percentage cover of vegetation overstory, for two distinct aspects of bird assemblages: community diversity (i.e. species richness) and population trends. We used four different long-term studies of open woodland habitats to test the consistency of the relationship between overstory percentage cover and bird species richness across a large spatial extent (>1000 km) in Australia. We then identified twelve bird species with long-term time-series data to test the relationship between change in overstory cover and populations trends. We found percentage cover performed consistently as a surrogate for species richness in three of the four sites. However, there was no clear pattern in the performance of change in percentage cover as a surrogate for population trends. Four bird species exhibited a significant relationship with change in percentage overstory cover in one study, but this was not found across multiple studies. These results demonstrate a lack of consistency in the relationship between change in overstory cover and population trends among bird species, both within and between geographic regions. Our study demonstrates that biodiversity surrogates representing community-level metrics may be consistent across regions, but provide only limited information about individual species population trends. Understanding the limitations of the information provided by a biodiversity surrogate can inform the appropriate context for its application. Crown Copyright © 2015 Published by Elsevier Ltd. All rights reserved.
Herbivory and fire interact to affect forest understory habitat, but not its use by small vertebrates
- Authors: Foster, Claire , Barton, Philip , Sato, C. F. , Wood, J. T. , Macgregor, C. I. , Lindenmayer, David
- Date: 2016
- Type: Text , Journal article
- Relation: Animal Conservation Vol. 19, no. 1 (2016), p. 15-25
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- Description: Herbivory and fire are two disturbances that often co-occur, but studies of their interactive effects are rare outside of grassland ecosystems. We experimentally tested the interactive effects of prescribed fire and macropod herbivory on forest understory vegetation and its vertebrate fauna. Fire and herbivory interacted synergistically to affect forest understory vegetation, with palatable plants showing poor post-fire recovery in unfenced sites compared with herbivore exclusion sites. Despite this strong interactive effect on vegetation, small vertebrates responded to the individual, and not the interactive effects of disturbance. The native insectivorous mammal Antechinus stuartii was more frequently encountered on large herbivore exclusion sites, as was the introduced European rabbit. In contrast, the small skink Lampropholis delicata was more common on sites with high densities of large herbivores. Skinks, snakes and European rabbits were also more active on burnt than unburnt sites. Our results suggest that it may be necessary to manage the macropod herbivore population after fire to prevent the decline of palatable plants, and maintain the dense habitat required by some small mammals. However, as the invasive rabbit was most active in macropod-free sites after fire, any management must include control of both types of herbivores. A mix of understory densities may also need to be maintained to ensure the persistence of species preferring more open habitats. Our study demonstrates that interactive effects of disturbance on vegetation communities may not lead to predictable effects on animals, and highlights the importance of considering both multiple stressors, and multiple species, in the management of disturbance regimes. © 2016 The Zoological Society of London.
Integrating theory into disturbance interaction experiments to better inform ecosystem management
- Authors: Foster, Claire , Sato, Chloe , Lindenmayer, David , Barton, Philip
- Date: 2016
- Type: Text , Journal article
- Relation: Global Change Biology Vol. 22, no. 4 (2016), p. 1325-1335
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- Description: Managing multiple, interacting disturbances is a key challenge to biodiversity conservation, and one that will only increase as global change drivers continue to alter disturbance regimes. Theoretical studies have highlighted the importance of a mechanistic understanding of stressor interactions for improving the prediction and management of interactive effects. However, many conservation studies are not designed or interpreted in the context of theory and instead focus on case-specific management questions. This is a problem as it means that few studies test the relationships highlighted in theoretical models as being important for ecological management. We explore the extent of this problem among studies of interacting disturbances by reviewing recent experimental studies of the interaction between fire and grazing in terrestrial ecosystems. Interactions between fire and grazing can occur via a number of pathways; one disturbance can modify the other's likelihood, intensity or spatial distribution, or one disturbance can alter the other's impacts on individual organisms. The strength of such interactions will vary depending on disturbance attributes (e.g. size or intensity), and this variation is likely to be nonlinear. We show that few experiments testing fire-grazing interactions are able to identify the mechanistic pathway driving an observed interaction, and most are unable to detect nonlinear effects. We demonstrate how these limitations compromise the ability of experimental studies to effectively inform ecological management. We propose a series of adjustments to the design of disturbance interaction experiments that would enable tests of key theoretical pathways and provide the deeper ecological understanding necessary for effective management. Such considerations are relevant to studies of a broad range of ecological interactions and are critical to informing the management of disturbance regimes in the context of accelerating global change. © 2016 John Wiley & Sons Ltd.
Long-term bird colonization and turnover in restored woodlands
- Authors: Lindenmayer, David , Lane, P. , Barton, Philip , Crane, Mason , Ikin, Karen
- Date: 2016
- Type: Text , Journal article
- Relation: Biodiversity and Conservation Vol. 25, no. 8 (2016), p. 1587-1603
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- Description: The long-term effectiveness of restored areas for biodiversity is poorly known for the majority of restored ecosystems worldwide. We quantified temporal changes in bird occurrence in restoration plantings of different ages and geometries, and compared observed patterns with a reference dataset from woodland remnants on the same farms as our plantings. Over time, bird species richness remained unchanged in spring but exhibited modest increases in winter. We found that wider plantings supported significantly greater bird species richness in spring and winter than narrow plantings. There was no evidence of a significant interaction between planting width and time. We recorded major temporal changes in the occurrence of a range of individual species that indicated a clear turnover of species as plantings matured. Our results further revealed marked differences in individual species occurrence between plantings and woodland remnants. Life-history attributes associated with temporal changes in the bird assemblage were most apparent in winter survey data, and included diet, foraging and nesting patterns, movement behaviour (e.g. migratory vs. dispersive), and body size. Differences in bird assemblages between plantings of different ages suggest that it is important that farms support a range of age classes of planted woodland, if the aim is to maximize the number of native bird species in restored areas. Our data also suggest that changes in the bird species occupying plantings of different ages can be anticipated in a broadly predictable way based on planting geometry (especially width) and key life-history attributes, particularly movement patterns and habitat and diet specialisation. © 2016, Springer Science+Business Media Dordrecht. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Philip Barton” is provided in this record**
Temporal trends in mammal responses to fire reveals the complex effects of fire regime attributes
- Authors: Lindenmayer, David , Blanchard, Wade , MacGregor, Christopher , Barton, Philip , Banks, Sam
- Date: 2016
- Type: Text , Journal article
- Relation: Ecological Applications Vol. 26, no. 2 (2016), p. 557-573
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- Description: Fire is a major ecological process in many ecosystems worldwide. We sought to identify which attributes of fire regimes affect temporal change in the presence and abundance of Australian native mammals. Our detailed study was underpinned by time series data on 11 mammal species at 97 long-term sites in southeastern Australia between 2003 and 2013. We explored how temporal aspects of fire regimes influenced the presence and conditional abundance of species. The key fire regime components examined were: (1) severity of a major fire in 2003, (2) interval between the last major fire (2003) and the fire prior to that, and (3) number of past fires. Our long-term data set enabled quantification of the interactions between survey year and each fire regime variable: an ecological relationship missing from temporally restricted studies. We found no evidence of any appreciable departures from the assumption of independence of the sites. Multiple aspects of fire regimes influenced temporal variation in the presence and abundance of mammals. The best models indicated that six of the 11 species responded to two or more fire regime variables, with two species influenced by all three fire regime attributes. Almost all species responded to time since fire, either as an interaction with survey year or as a main effect. Fire severity or its interaction with survey year was important for most terrestrial rodents. The number of fires at a site was significant for terrestrial rodents and several other species. Our findings contain evidence of the effects on native mammals of heterogeneity in fire regimes. Temporal response patterns of mammal species were influenced by multiple fire regime attributes, often in conjunction with survey year. This underscores the critical importance of long-term studies of biota that are coupled with data sets characterized by carefully documented fire history, severity, and frequency. Long-term studies are essential to predict animal responses to fires and guide management of when and where (prescribed) fire or, conversely, long-unburned vegetation is needed. The complexity of observed responses highlights the need for large reserves in which patterns of heterogeneity in fire regimes can be sustained in space and over time. © 2015 by the Ecological Society of America. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Philip Barton” is provided in this record**
Wildlife conservation in farm landscapes
- Authors: Lindenmayer, David , Michael, Damian , Crane, Mason , Okayda, Sachiko , Florance, Daniel , Barton, Philip , Ikin, Karen
- Date: 2016
- Type: Text , Book
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- Description: An increasing number of Australians want to be assured that the food and fibre being produced on this continent have been grown and harvested in an ecologically sustainable way. Ecologically sustainable farming conserves the array of species that are integral to key ecological processes such as pollination, seed dispersal, natural pest control and the decomposition of waste. Wildlife Conservation in Farm Landscapes communicates new scientific information about best practice ways to integrate conservation and agriculture in the temperate eucalypt woodland belt of eastern Australia. It is based on the large body of scientific literature in this field, as well as long-term studies at 790 permanent sites on over 290 farms extending throughout Victoria, New South Wales and south-east Queensland. Richly illustrated, with chapters on birds, mammals, reptiles, invertebrates and plants, this book illustrates how management interventions can promote nature conservation and what practices have the greatest benefit for biodiversity. Together the new insights in this book inform whole-of-farm planning. Wildlife Conservation in Farm Landscapes is an ideal resource for land managers and farmers interested in integrating farming and environmental values and anyone interested in biodiversity in woodlands and agricultural zones. Recipient of a 2017 Whitley Awards Certificate of Commendation for Conservation in Action
Contrasting beetle assemblage responses to cultivated farmlands and native woodlands in a dynamic agricultural landscape
- Authors: Ng, Katherina , Driscoll, Don , MacFadyen, Sarina , Barton, Philip , McIntyre, Sue , Lindenmayer, David
- Date: 2017
- Type: Text , Journal article
- Relation: Ecosphere Vol. 8, no. 12 (2017), p.
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- Description: There is an urgent need to identify ways of managing agricultural landscapes for biodiversity conservation without reducing food production. Farming practices that consider spatiooral heterogeneity of farm fields may be a feasible alternative to large-scale revegetation of farmlands for maintaining arthropod biodiversity and their important ecological function. We examined seasonal differences in beetle assemblages in woodland remnants and four adjoining farmland uses in a highly modified agricultural landscape in southeastern Australia. The farmland uses were crops, fallows, and two restoration treatments (fine woody debris applied over harvested crop fields, and restoration plantings). Unexpectedly, overall species richness was significantly lower in remnants than in adjacent farmlands. Remnants and farmlands supported significantly different assemblages, with a third of species found in both habitats. Abundance responses were taxon-specific and influenced by interactions between land use and season. In particular, predator abundance was significantly higher in plantings and fallows during spring compared to summer. Detritivore abundance was significantly higher in the woody debris compared to the adjacent remnants. Herbivore abundance did not differ between remnants and farmlands over time. Complex responses provide strong support for a mosaic of land uses to effectively conserve different beetle groups. Species richness results suggest that further agricultural intensification, in farm fields and through the removal of remnant vegetation, risks reducing beetle diversity in this region. Maintaining farmland heterogeneity with a mix of low-intensity land uses, such as conservation tillage, crop-fallow rotation, restoration plantings, and the novel application of fine woody debris over cultivated fields, may provide seasonal refuge and resources for beetles. © 2017 Ng et al.
Effects of a large wildfire on vegetation structure in a variable fire mosaic
- Authors: Foster, C. , Barton, Philip , Robinson, N. , MacGregor, C. , Lindenmayer, David
- Date: 2017
- Type: Text , Journal article
- Relation: Ecological Applications Vol. 27, no. 8 (2017), p. 2369-2381
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- Description: Management guidelines for many fire-prone ecosystems highlight the importance of maintaining a variable mosaic of fire histories for biodiversity conservation. Managers are encouraged to aim for fire mosaics that are temporally and spatially dynamic, include all successional states of vegetation, and also include variation in the underlying "invisible mosaic" of past fire frequencies, severities, and fire return intervals. However, establishing and maintaining variable mosaics in contemporary landscapes is subject to many challenges, one of which is deciding how the fire mosaic should be managed following the occurrence of large, unplanned wildfires. A key consideration for this decision is the extent to which the effects of previous fire history on vegetation and habitats persist after major wildfires, but this topic has rarely been investigated empirically. In this study, we tested to what extent a large wildfire interacted with previous fire history to affect the structure of forest, woodland, and heath vegetation in Booderee National Park in southeastern Australia. In 2003, a summer wildfire burned 49.5% of the park, increasing the extent of recently burned vegetation (<10 yr post-fire) to more than 72% of the park area. We tracked the recovery of vegetation structure for nine years following the wildfire and found that the strength and persistence of fire effects differed substantially between vegetation types. Vegetation structure was modified by wildfire in forest, woodland, and heath vegetation, but among-site variability in vegetation structure was reduced only by severe fire in woodland vegetation. There also were persistent legacy effects of the previous fire regime on some attributes of vegetation structure including forest ground and understorey cover, and woodland midstorey and overstorey cover. For example, woodland midstorey cover was greater on sites with higher fire frequency, irrespective of the severity of the 2003 wildfire. Our results show that even after a large, severe wildfire, underlying fire histories can contribute substantially to variation in vegetation structure. This highlights the importance of ensuring that efforts to reinstate variation in vegetation fire age after large wildfires do not inadvertently reduce variation in vegetation structure generated by the underlying invisible mosaic. © 2017 by the Ecological Society of America.
Optimal taxonomic groups for biodiversity assessment: a meta-analytic approach
- Authors: Westgate, Martin , Tulloch, Ayesha , Barton, Philip , Pierson, Jennifer , Lindenmayer, David
- Date: 2017
- Type: Text , Journal article
- Relation: Ecography Vol. 40, no. 4 (2017), p. 539-548
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- Description: A fundamental decision in biodiversity assessment is the selection of one or more study taxa, a choice that is often made using qualitative criteria such as historical precedent, ease of detection, or available technical or taxonomic expertise. A more robust approach would involve selecting taxa based on the a priori expectation that they will provide the best possible information on unmeasured groups, but data to inform such hypotheses are often lacking. Using a global meta-analysis, we quantified the proportion of variability that each of 12 taxonomic groups (at the Order level or above) explained in the richness or composition of other taxa. We then applied optimization to matrices of pairwise congruency to identify the best set of complementary surrogate groups. We found that no single taxon was an optimal surrogate for both the richness and composition of unmeasured taxa if we used simple methods to aggregate congruence data between studies. In contrast, statistical methods that accounted for well-known drivers of cross-taxon congruence (spatial extent, grain size, and latitude) lead to the prioritization of similar surrogates for both species richness and composition. Advanced statistical methods were also more effective at describing known ecological relationships between taxa than simple methods, and show that congruence is typically highest between taxonomically and functionally dissimilar taxa. Birds and vascular plants were most frequently selected by our algorithm as surrogates for other taxonomic groups, but the extent to which any one taxon was the ‘optimal’ choice of surrogate for other biodiversity was highly context-dependent. In the absence of other information – such as in data-poor areas of the globe, and under limited budgets for monitoring or assessment – ecologists can use our results to assess which taxa are most likely to reflect the distribution of the richness or composition of ‘total’ biodiversity. © 2016 The Authors
Remnant vegetation, plantings and fences are beneficial for reptiles in agricultural landscapes
- Authors: Pulsford, Stephanie , Driscoll, Don , Barton, Philip , Lindenmayer, David
- Date: 2017
- Type: Text , Journal article
- Relation: Journal of Applied Ecology Vol. 54, no. 6 (2017), p. 1710-1719
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- Description: Managing agricultural landscapes for biodiversity conservation is increasingly difficult as land use is modified or intensified for production. Finding ways to mitigate the negative effects of agriculture on biodiversity is therefore critical. We asked the question: How do remnant patches, paddock types and grazing regimes influence reptile assemblages in a grazing landscape? At 12 sites, we surveyed reptiles and environmental covariates in remnant woodland patches and in four paddock types: (i) grazed pasture, (ii) linear plantings, (iii) coarse woody debris (CWD) added to grazed pasture and (iv) fences between grazed pasture. Each site was either continuously or rotationally grazed. Remnant vegetation and other vegetation attributes such as tree cover and leaf litter greatly influenced reptiles. We recorded higher reptile abundance and species richness in areas with more tree cover and leaf litter. For rare species (captured in ≤4 sites <70 captures), there were 5·7 more animals and 2·6 more species in sites with 50% woody cover within 3 km compared to 5% woody cover. The abundance and richness of rare species, and one common species differed between paddock types and were higher in linear plantings and fence transects compared to CWD and pasture transects. Synthesis and applications. Grazed paddocks, particularly those with key features such as fences and plantings can provide habitat for reptiles. This suggests that discrete differentiation between patch and matrix does not apply for reptiles in these systems. Management to promote reptile conservation in agricultural landscapes should involve protecting existing remnant vegetation, regardless of amount; and promote key habitat features of trees, leaf litter and shrubs. Establishing plantings and fences is important as they support high numbers of less common reptiles and may facilitate reptiles to move through and use greater amounts of the landscape. © 2017 The Authors. Journal of Applied Ecology © 2017 British Ecological Society
Beetle’s responses to edges in fragmented landscapes are driven by adjacent farmland use, season and cross-habitat movement
- Authors: Ng, Katherine , Barton, Philip , Macfadyen, Sarina , Lindenmayer, David , Driscoll, Don
- Date: 2018
- Type: Text , Journal article
- Relation: Landscape Ecology Vol. 33, no. 1 (2018), p. 109-125
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- Description: Context: Farming practices influence the degree of contrast between adjoining habitats, with consequences for biodiversity and species movement. Little is known, however, on insect community responses to different kinds of edges over time, and the extent of cross-habitat movement in agricultural landscapes. Objective: To determine temporal changes in beetle responses to different farmland-woodland edges, and document cross-habitat movement. Methods: We examined species richness, abundance, and movement across edges between remnant woodlands and four farmland uses (plantings, fallow, annual crops, woody debris applied over crops post-harvest) in southeastern Australia. We used directional pitfall traps to infer movement, and sampled at edges, and 20 and 200 m on both sides of edges, during spring and summer. Results: Detritivore and predator abundance varied between seasons across the edge between woodlands and all farmlands, but seasonal differences were weaker for fallow-woodland and woody debris-woodland edges. Detritivores moved from farmlands towards woodlands, but not across fallow-woodlands and woody debris-woodlands edges during summer. During summer, predators showed short-range movement towards edges from all farmlands except plantings, and towards woody debris from woodlands. Edges showed temporally stable predator richness and higher herbivore richness than adjoining habitats. Conclusions: Farmland use and season interactively affect beetle abundance across farmland-woodland edges. Woody debris can reduce seasonal fluctuations in beetle edge responses and increase permeability for cross-habitat movement, while plantings provide habitat during summer. Edges provide important resources for beetles in adjoining habitats, however, seasonal movement of predators specifically into edges may affect prey assemblages—a link requiring further study. © 2017, Springer Science+Business Media B.V.
Conservation conundrums and the challenges of managing unexplained declines of multiple species
- Authors: Lindenmayer, David , Wood, Jeff , MacGregor, Christopher , Foster, Claire , Barton, Philip
- Date: 2018
- Type: Text , Journal article
- Relation: Biological Conservation Vol. 221, no. (2018), p. 279-292
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- Description: The conventional approach to conserving threatened biota is to identify drivers of decline, instigate actions to mitigate threatening processes, and monitor interventions to test their effectiveness and ensure target species recover. In Australia, predation by introduced predators is a threatening process for many native mammals. Here we report the results of a 15 year monitoring study in an iconic Australian reserve, Booderee National Park, where exotic Red Fox (Vulpes vulpes) populations have been controlled through an intensive poison baiting program since 2003. Unexpectedly, we documented the collapse of native mammal fauna during this period, including fully arboreal species that should be largely unaffected by fox predation – such as the nationally Vulnerable Greater Glider (Petauroides volans) and Common Ringtail Possum (Pseudocheirus peregrinus). We used path analysis to explore potential causes of these unexpected declines. We found no compelling evidence to support hypotheses that competition with increasing native species, native predator release, or increases in native herbivores underpinned mammal declines. Beyond the path analysis, data from other studies completed both inside Booderee National Park and outside (where intensive fox baiting does not occur yet depleted fauna species remain), allowed us to rule out several drivers of change. The temporal declines we documented for arboreal marsupials were not anticipated nor explained by any clear mechanism. We propose the use of experimentally-guided reintroductions and translocations to: (1) restore empty niches such as the currently vacant apex mammal predator niche, (2) reconstruct the now depleted arboreal marsupial guild, and (3) further test key hypotheses associated with mammal decline. We also suggest that given the potential for perverse outcomes following large-scale management interventions (even those where there is high confidence of success), wildlife managers should consider maintaining reference areas (where there is no management intervention). Finally, as the declines we documented were unexpected and rapid, there is a clear need to develop more sensitive early warning signals to alert conservation managers to impending problems, allowing them to alter management regimes before major declines occur. © 2018 Elsevier Ltd. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Philip Barton is provided in this record**
Disentangling the effects of farmland use, habitat edges, and vegetation structure on ground beetle morphological traits
- Authors: Ng, Katherina , Barton, Philip , Blanchard, Wade , Evans, Maldwyn , Lindenmayer, David
- Date: 2018
- Type: Text , Journal article
- Relation: Oecologia Vol. 188, no. 3 (2018), p. 645-657
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- Description: Land-use change due to agriculture has a major influence on arthropod biodiversity, and may influence species differently depending on their traits. It is unclear how species traits vary across different land uses and their edges, with most studies focussing on single habitat types and overlooking edge effects. We examined variation in morphological traits of carabid beetles (Coleoptera:Carabidae) on both sides of edges between woodlands and four adjoining, but contrasting farmland uses in an agricultural landscape. We asked: (1) how do traits differ between woodlands and different adjoining farmland uses (crop, fallow, restoration planting, and woody debris applied over crop), and do effects depend on increasing distances from the farmland–woodland edge? (2) Does vegetation structure explain observed effects of adjoining farmland use and edge effects on these traits? We found that carabid communities varied in body size and shape, including traits associated with diet, robustness, and visual ability. Smaller sized species were associated with woodlands and larger sized species with farmlands. Farmland use further influenced these associations, where woodlands adjoining plantings supported smaller species, while fallows and crops supported larger species. Vegetation structure significantly influenced body size, flying ability, and body shape, and helped explain the effects of farmland use and distance from edges on body size. We highlight the important role of vegetation structure, farmland use, and edge effects in filtering the morphological traits of carabid assemblages across a highly modified agricultural landscape. Our findings suggest that farmland management can influence body size and dispersal-related traits in farmland and adjacent native vegetation. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Philip Barton” is provided in this record**
Dynamic effects of ground-layer plant communities on beetles in a fragmented farming landscape
- Authors: Ng, Katherina , McIntyre, Sue , Macfadyen, Sarina , Barton, Philip , Driscoll, Don , Lindenmayer, David
- Date: 2018
- Type: Text , Journal article
- Relation: Biodiversity and Conservation Vol. 27, no. 9 (2018), p. 2131-2153
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- Description: Vegetation effects on arthropods are well recognized, but it is unclear how different vegetation attributes might influence arthropod assemblages across mixed-agricultural landscapes. Understanding how plant communities influence arthropods under different habitat and seasonal contexts can identify vegetation management options for arthropod biodiversity. We examined relationships between vegetation structure, plant species richness and plant species composition, and the diversity and composition of beetles in different habitats and time periods. We asked: (1) What is the relative importance of plant species richness, vegetation structure and plant composition in explaining beetle species richness, activity-density and composition? (2) How do plant-beetle relationships vary between different habitats over time? We sampled beetles using pitfall traps and surveyed vegetation in three habitats (woodland, farmland, their edges) during peak crop growth in spring and post-harvest in summer. Plant composition better predicted beetle composition than vegetation structure. Both plant richness and vegetation structure significantly and positively affected beetle activity-density. The influence of all vegetation attributes often varied in strength and direction between habitats and seasons for all trophic groups. The variable nature of plant-beetle relationships suggests that vegetation management could be targeted at specific habitats and time periods to maximize positive outcomes for beetle diversity. In particular, management that promotes plant richness at edges, and promotes herbaceous cover during summer, can support beetle diversity. Conserving ground cover in all habitats may improve activity-density of all beetle trophic groups. The impacts of existing weed control strategies in Australian crop margins on arthropod biodiversity require further study. © 2018, Springer Science+Business Media B.V., part of Springer Nature.
Effects of fire regime on plant species richness and composition differ among forest, woodland and heath vegetation
- Authors: Foster, Claire , Barton, Philip , MacGregor, Christopher , Catford, Jane , Blanchard, Wade , Lindenmayer, David
- Date: 2018
- Type: Text , Journal article
- Relation: Applied Vegetation Science Vol. 21, no. 1 (2018), p. 132-143
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- Description: Question: Do the effects of fire regimes on plant species richness and composition differ among floristically similar vegetation types?. Location: Booderee National Park, south-eastern Australia. Methods: We completed floristic surveys of 87 sites in Sydney Coastal dry sclerophyll vegetation, where fire history records have been maintained for over 55 years. We tested for associations between different aspects of the recent fire history and plant species richness and composition, and whether these relationships were consistent among structurally defined forest, woodland and heath vegetation types. Results: The relationship between fire regime variables and plant species richness and composition differed among vegetation types, despite the three vegetation types having similar species pools. Fire frequency was positively related to species richness in woodland, negatively related to species richness in heath, and unrelated to species richness in forest. These different relationships were explained by differences in the associations between fire history and species traits among vegetation types. The negative relationship between fire frequency and species richness in heath vegetation was underpinned by reduced occurrence of resprouting species at high fire frequency sites (more than four fires in 55 years). However, in forest and woodland vegetation, resprouting species were not negatively associated with fire frequency. Conclusions: We hypothesize that differing relationships among vegetation types were underpinned by differences in fire behaviour, and/or biotic and abiotic conditions, leading to differences in plant species mortality and post-fire recovery among vegetation types. Our findings suggest that even when there is a high proportion of shared species between vegetation types, fires can have very different effects on vegetation communities, depending on the structural vegetation type. Both research and management of fire regimes may therefore benefit from considering vegetation types as separate management units. © 2017 International Association for Vegetation Science
Reptiles and frogs use most land cover types as habitat in a fine-grained agricultural landscape
- Authors: Pulsford, Stephanie , Barton, Philip , Driscoll, Don , Kay, Geoffrey , Lindenmayer, David
- Date: 2018
- Type: Text , Journal article
- Relation: Austral Ecology Vol. 43, no. 5 (2018), p. 502-513
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- Description: Agricultural landscapes comprise much of the earth's terrestrial surface. However, knowledge about how animals use and move through these landscapes is limited, especially for small and cryptic taxa, such as reptiles and amphibians. We aimed to understand the influence of land use on reptile and frog movement in a fine-grained grazing landscape. We surveyed reptiles and frogs using pitfall and funnel traps in transects located in five land use types: 1) woodland remnants, 2) grazed pastures, 3) coarse woody debris added to grazed pastures, 4) fences in grazed pastures and 5) linear plantings within grazed pastures. We found that the different land cover types influenced the types and distances moved by different species and groups of species. Reptiles moved both within, and out of, grazed paddocks more than they did in woodland remnants. In contrast, frogs exhibited varying movement behaviours. The smooth toadlet (Uperoleia laevigata) moved more often and longer distances within remnants than within paddocks. The spotted marsh frog (Limnodynastes tasmaniensis) moved out of grazed pastures more than out of pastures with coarse woody debris added or fences and were never recaptured in plantings. We found that most recaptured reptiles and frogs (76.3%) did not move between trapping arrays, which added to evidence that they perceived most of the land cover types as habitat. We suggest that even simple fences may provide conduits for movement in the agricultural landscape for frogs. Otherwise, most reptile and frog species used all land cover types as habitat, though of varying quality. Reptiles appeared to perceive the woodland remnants as the highest quality habitat. This landscape is fine-grained which may facilitate movement and persistence due to high heterogeneity in vegetation cover over short distances. Therefore, intensification and increasing the size of human land use may have negative impacts on these taxa. © 2018 Ecological Society of Australia