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Conservation managers regularly burn vegetation to regenerate habitat for fire-dependent species. When determining the time since fire at which to burn, managers model change in a species’ occurrence over time, post-fire (fire-response curve) and identify the time since fire associated with decline in occurrence. However, where species exhibit variability in their fire response across space, using a single fire-response curve to determine the timing of burns may lead to burning habitat at an inappropriate time since fire. We tested if elevation, local topography, soil properties, vegetation type or evapotranspiration affect the fire response of the endangered Mallee Emu-wren Stipiturus mallee and its hummock-grass habitat Triodia scariosa in southeastern Australia (n = 217). Previous work on the Mallee Emu-wren found a unimodal fire response with decline in occurrence at ~30–50 yr since fire and a time window of occurrence of ~30 yr. We found that time since fire and elevation interact to affect the Mallee Emu-wren fire response. At high elevations (55–98 m), Mallee Emu-wrens declined in occurrence at ~50 yr since fire, with a time window of occurrence of 20–40 yr. However, at low elevations (28–55 m), Mallee Emu-wrens showed no decline in occurrence with increasing time since fire with a time window of occurrence of up to 107 yr. Extent cover of Tall T. scariosa showed similar patterns to the Mallee Emu-wren, indicating that vegetation structure is a likely driver of variability in the Mallee Emu-wren fire response. We speculate that the effect of low elevation is mediated by increased soil nutrient and water availability for key plants. We used our findings to map the appropriate time since fire at which to burn to regenerate habitat for the Mallee Emu-wren across the study region. We recommend no burning for regeneration across one-third of potential habitat, because the Mallee Emu-wren showed no decline in occurrence in these areas. We recommend managers model variability in species’ fire responses across space to improve the timing of burns for regeneration.

BackgroundPredicting faunal responses to fire is complex due to regional differences in fire-vegetation dynamics, necessitating locally calibrated studies.AimsThis study examined the effects of fire-mediated vegetation succession on (1) the richness, diversity and composition of small vertebrate communities and (2) individual species abundance in Triodia-mallee landscapes.MethodsWe sampled small vertebrates across 12 sites at Nanya Station, NSW, Australia, with fire histories spanning 1, 18 and >40 years since the last fire (YSLF).Key results531 vertebrates from 39 species were recorded. There was strong evidence that fire history influenced vegetation structure, which shaped reptile community composition and species abundance. Early successional sites (1 YSLF) supported higher abundances of lizards such as Ctenotus regius, Lerista labialis and Lucasium damaeum. These species peaked 1-year post-fire before declining by 18 YSLF. In contrast, the dasyurid Ningaui yvonneae was most abundant 20–40 YSLF, correlating with dense spinifex, and was nearly absent at recently burned sites.ConclusionsFire history drives varied successional responses among species, with some benefiting from early post-fire conditions and others requiring mature spinifex habitat.ImplicationsRegion-specific studies are essential for effective conservation and land management. Long-term research is needed to understand successional dynamics and guide fire management strategies.

Semi‐arid mallee landscapes are shaped by wildfires. Due to climate change, wildfires are expected to become more frequent and intense, making their management a conservation priority. Ants are often used as bioindicators in land management studies, as their composition, richness, and abundance respond to disturbances, including wildfires, both directly and indirectly through habitat modification. In the semi‐arid zone of western New South Wales, Australia, we examined how time‐since‐fire influences ant species richness, abundance, and community composition and assessed whether fire‐induced changes in vegetation composition explain the observed patterns in ant community structure. We sampled ants at five sites that last burned 3, 5, 9, 26, and 34 years ago, respectively. We identified 59 ant species from 20 genera in a total of 16,360 sampled ants. We found that post‐fire ant communities exhibited higher abundance immediately after fire, while species richness increased with time‐since‐fire. Early successional stages with greater shrub density favored dominant and opportunistic ant species, whereas later stages with increased tree and grass cover supported more diverse ant communities. These results demonstrate that fire drives successional specialization in ant communities through niche filtering. Maintaining heterogeneous fire‐age vegetation mosaics is therefore critical for conserving landscape‐level biodiversity in fire‐regulated mallee ecosystems. We sampled ants from five sites with varying fire histories (3, 5, 9, 26, and 34 years since the last fire). A total of 16,360 ants were collected, and 59 species across 20 genera were identified. Our results indicate that total ant abundance was higher in recently burnt sites and decreased with increasing time‐since‐fire, while ant species richness was higher in older burn sites. We also found that ant composition differed significantly in sites with different times‐since‐fire. Early post‐fire stages, characterized by high shrub cover, supported dominant and opportunistic ant species, whereas later successional stages, with greater tree and grass cover, were associated with higher ant species diversity.

Essential oils from the Western Australian (WA) Eucalyptus mallee species Eucalyptus loxophleba, Eucalyptus polybractea, and Eucalyptus kochii subsp. plenissima and subsp. borealis were hydrodistilled from the leaves and then analysed by gas chromatography–mass spectrometry in addition to a commercial Eucalyptus globulus oil and 1,8-cineole. The main component of all oils was 1,8-cineole at 97.32% for E. kochii subsp. borealis, 96.55% for E. kochii subsp. plenissima, 82.95% for E. polybractea, 78.78% for E. loxophleba 2, 77.02% for E. globulus, and 66.93% for E. loxophleba 1. The Eucalyptus oils exhibited variable antimicrobial activity determined by broth microdilution, with E. globulus and E. polybractea oils showing the highest activities. The majority of microorganisms were inhibited or killed at concentrations ranging from 0.25% to 8.0% (v/v). Enterococcus faecalis and Candida albicans were the least susceptible organisms, whilst Acinetobacter baumannii was the most sensitive. In conclusion, all oils from WA Eucalyptus species showed microorganism inhibitory activity, although this varied according to both the Eucalyptus species and the microorganism tested. These data demonstrate that WA Eucalyptus oils show activity against a range of medically important pathogens and therefore have potential as antimicrobial agents.

1. Managing fire to achieve hazard reduction while providing for biodiversity conservation is complex in fire-prone regions. This challenge is exacerbated by limited understanding of post-fire changes in habitat and fuel attributes over time-scales commensurate with their development, and a paucity of empirical research integrating the effects of fire on these attributes. 2. We used a 110-year post-fire chronosequence to investigate temporal development in habitat resources used by fauna, and fuels for fire in semi-arid Mallee vegetation, south-eastern Australia. Fire-history mapping previously limited investigation to 35 years post-fire. The patterns of temporal change over 110 years for 13 variables, representing key attributes of habitat and fuel, were explored using nonlinear mixed models and data from 549 sites. 3. Most habitat and fuel attributes exhibited changes in abundance and rate of development over extended periods, emphasizing the importance of documenting post-fire dynamics over long time-frames. Further, developmental patterns were mostly nonlinear, indicating that a shorter temporal perspective (e.g. 20-30 years post-fire) may obscure, or provide an inaccurate understanding of, long-term changes. 4. There were striking differences in the post-fire dynamics of some habitat and fuel attributes. Leaf litter and spinifex grass Triodia scariosa, which function as both habitat and fuel, increased rapidly after fire followed by a plateau or slow decline after 20-30 years. In contrast, live tree stems were not predicted to develop hollows until 40 years, after which time the density of live hollow-bearing stems, an important habitat feature, increased steadily. 5. Synthesis and applications. Fire affects the development and abundance of resources over substantially longer periods than can be examined using fire-mapping based on satellite imagery. Our results demonstrate that post-fire changes in mallee vegetation influence fire hazard and faunal habitat in different ways. Critically, the cover/abundance of most primary fuel sources did not increase substantially beyond around 30 years post-fire; whereas important habitat attributes changed in ways that affect faunal occurrence for over a century. Fire management must explicitly acknowledge the potential for fire to affect fauna and fuel differently, and for these effects to operate over time-frames that may extend well beyond current understanding.

Fire is both a widespread natural disturbance that affects the distribution of species and a tool that can be used to manage habitats for species. Knowledge of temporal changes in the occurrence of species after fire is essential for conservation management in fire-prone environments. Two key issues are: whether postfire responses of species are idiosyncratic or if multiple species show a limited number of similar responses; and whether such responses to time since fire can predict the occurrence of species across broad spatial scales. We examined the response of bird species to time since fire in semiarid shrubland in southeastern Australia using data from surveys at 499 sites representing a 100-year chronosequence. We used nonlinear regression to model the probability of occurrence of 30 species with time since fire in two vegetation types, and compared species' responses with generalized response shapes from the literature. The occurrence of 16 species was significantly influenced by time since fire: they displayed six main responses consistent with generalized response shapes. Of these 16 species, 15 occurred more frequently in mid- or later-successional vegetation (>20 years since fire), and only one species occurred more often in early succession (<5 years since fire). The models had reasonable predictive ability for eight species, some predictive ability for seven species, and were little better than random for one species. Bird species displayed a limited range of responses to time since fire; thus a small set of fire ages should allow the provision of habitat for most species. Postfire successional changes extend for decades and management of the age class distribution of vegetation will need to reflect this timescale. Response curves revealed important seral stages for species and highlighted the importance of mid- to late-successional vegetation (>20 years). Although time since fire clearly influences the distribution of numerous bird species, predictive models of the spatial distribution of species in fire-prone landscapes need to incorporate other factors in addition to time since fire.

Fire is a major disturbance process in many ecosystems world-wide, resulting in spatially and temporally dynamic landscapes. For populations occupying such environments, fire-induced landscape change is likely to influence population processes, and genetic patterns and structure among populations. The Mallee Emu-wren Stipiturus mallee is an endangered passerine whose global distribution is confined to fire-prone, semi-arid mallee shrublands in south-eastern Australia. This species, with poor capacity for dispersal, has undergone a precipitous reduction in distribution and numbers in recent decades. We used genetic analyses of 11 length-variable, nuclear loci to examine population structure and processes within this species, across its global range. Populations of the Mallee Emu-wren exhibited a low to moderate level of genetic diversity, and evidence of bottlenecks and genetic drift. Bayesian clustering methods revealed weak genetic population structure across the species' range. The direct effects of large fires, together with associated changes in the spatial and temporal patterns of suitable habitat, have the potential to cause population bottlenecks, serial local extinctions and subsequent recolonisation, all of which may interact to erode and homogenise genetic diversity in this species. Movement among temporally and spatially shifting habitat, appears to maintain long-term genetic connectivity. A plausible explanation for the observed genetic patterns is that, following extensive fires, recolonisation exceeds in-situ survival as the primary driver of population recovery in this species. These findings suggest that dynamic, fire-dominated landscapes can drive genetic homogenisation of populations of species with low-mobility and specialised habitat that otherwise would be expected to show strongly structured populations. Such effects must be considered when formulating management actions to conserve species in fire-prone systems.

The COVID-19 pandemic adversely impacted the mental health and wellbeing of healthcare workers (HCW). Drawn from the theory of salutogenesis, Sense of Coherence (SOC) assesses the extent to which individuals perceive their life experiences as comprehensible, manageable, and meaningful, and is considered an important health promoting resource for HCWs’ resilience and coping under stressful circumstances. However, little is known about its measurement in HCW populations, and the current discrepancy regarding SOC dimensionality continues to limit salutogenic research and application. Previous studies have used factor analytic, Rasch and SEM approaches for assessing SOC dimensionality, which have since been challenged for accuracy. This study applied a novel psychometric methodology, namely Exploratory Graph Analysis (EGA), to revisit the dimensionality of the SOC-13 scale in a regional and rural Australian HCW cohort at 12-month follow-up ( n  = 649; complete SOC-13 cases n  = 597), broadly representative of the Loddon Mallee healthcare workforce demographics. Results support a refined 12-item, unidimensional SOC instrument, achieved by removing one redundant item (SOCQ2) highly overlapping in content with SOCQ3, and demonstrated strong internal consistency and validity related to depression, anxiety, and resilience. Further research is needed to explore dimensionality across populations and to improve missing data treatment in network analyses.

Aim: A common strategy for conserving biodiversity in fire-prone environments is to maintain a diversity of post-fire age classes at the landscape scale, under the assumption that 'pyrodiversity begets biodiversity'. Another strategy is to maintain extensive areas of a particular seral state regarded as vital for the persistence of threatened species, under the assumption that this will also cater for the habitat needs of other species. We investigated the likely effects of these strategies on bird assemblages in tree mallee vegetation, characterized by multistemmed Eucalyptus species, where both strategies are currently employed. Location: The semi-arid Murray Mallee region of south-eastern Australia. Methods: We systematically surveyed birds in 26 landscapes (each 4-km diameter), selected to represent gradients in the diversity of fire age classes and the proportion of older vegetation (> 35 years since fire). Additional variables were measured to represent underlying vegetation- or fire-mediated properties of the landscape, as well as its biogeographic context. We used an informationtheoretic approach to investigate the relationships between these predictor variables and the species richness of birds (total species, threatened species and rare species). Results: Species richness of birds was not strongly associated with fire-mediated heterogeneity. Species richness was associated with increasing amounts of older vegetation in landscapes, but not with the proportion of recently burned vegetation in landscapes. Main conclusions: The preference of many mallee birds for older vegetation highlights the risk of a blanket application of the 'pyrodiversity begets biodiversity' paradigm. If application of this paradigm involved converting large areas from long unburned to recently burned vegetation to increase fire-mediated heterogeneity in tree mallee landscapes, our findings suggest that this could threaten birds. This research highlights the value of adopting a landscape-scale perspective when evaluating the utility of fire-management strategies intended to benefit biodiversity.

Coastal mallee shrubland wildfires present challenges for accurately predicting fire spread sustainability and rate of spread. In this study, we assess the fuel drivers contributing to coastal mallee shrubland fires. A review of shrubland fire behaviour models and fuel metrics was conducted to determine the current practice of assessing shrubland fuels. This was followed by workshops designed to elicit which fuel structural metrics are key drivers of fire behaviour in coastal mallee shrublands. We found that height is the most commonly used fuel metric in shrubland fire models due to the ease of collection in situ or as a surrogate for more complex fuel structures. Expert workshop results suggest that cover and connectivity metrics are key to modelling fire behaviour in coastal mallee shrublands. While height and cover are frequently used in fire models, we conclude that connectivity metrics would offer additional insights into fuel drivers in mallee shrublands. Future research into coastal mallee fire behaviour should include the measurements of fuel height, cover, and horizontal and vertical connectivity.