Owen Francis Price

Garden management plays a crucial role in reducing bushfire risk at the wildland-urban interface, yet implementation of fire-safe practices remains challenging. An analysis of garden assessments and in-depth interviews with 23 property owners in Greater Hobart, Tasmania, examined how technical, social and emotional factors influence garden bushfire adaptation decisions. Using the Cynefin framework and complexity theory, this study demonstrates that successful adaptation addresses multiple domains of complexity, from straightforward vegetation management to complex socio-emotional attachments to garden spaces. Findings reveal that while personalised garden assessment reports can motivate change, their success depends on a broader set of conditions. Barriers include practical constraints (e.g. green waste management), emotional attachments to garden elements and difficulties obtaining context-specific guidance. By applying the As Low As Reasonably Practicable (ALARP) principle, this study identified cost-effective interventions across the 4 avenues of institutional support and resource management, individual garden bushfire adaptation, personalised technical guidance and community support networks. This research suggests that creating fire-adapted gardens requires coordinated support systems that address both practical implementation challenges and emotional connections to garden spaces.

Ferrets have long served as an important animal model for the study of respiratory infections, inhalation toxicology, and aerosolized therapeutics because of their anatomical and physiological similarities to humans. Despite their widespread use, quantitative models describing particle deposition within the ferret lung remain limited. In this study, we developed a mechanistic dosimetry model to predict total and regional deposition of inhaled inert particles in the ferret lower respiratory tract (LRT). Two anatomically based lung geometries were constructed using available morphometric data: a modified typical-path symmetric lung geometry and a more physiologically representative 2-path symmetric lung geometry. Both models were designed to yield realistic lung volumes and airway counts while accommodating the limited availability of airway measurements. Airway dimensions were derived from published morphometric data and extended using sigmoidal curve fits to represent the complete tracheobronchial (TB) and pulmonary (PUL) regions. Lung ventilation was modeled assuming uniform pleural pressure, with airflow distributed proportionally to distal lung volume. Particle transport and deposition were simulated using a one-dimensional (1D) advection-diffusion framework incorporating gravitational settling, inertial impaction, and Brownian diffusion. The 2-path symmetric lung geometry enables more realistic predictions of particle deposition throughout the lung, particularly with respect to deposition as a function of lung depth, allowing direct comparison of predicted deposition with in vivo imaging measurements.

Background: Prescribed burning is a widely used fire management strategy for maintaining socioeconomic and ecological resilience by mitigating the impacts of wildfires. Monitoring the effectiveness of prescribed burns on future fire spread, however, is challenged by limited data availability and quality. Aims: We sought to create a simple, replicable approach to assess the likelihood of an unplanned fire being limited or contained by a previous fire using only feature boundaries. Methods: We present methods to calculate the percentage of the back half of a feature boundary that was burnt in a wildfire encounter. We then model the through-burn probability against factors with known relationships to prescribed burn effectiveness and wildfire behaviour using 20 years of data for Victoria, Australia. Key results: The likelihood of a prescribed burn limiting a subsequent fire is primarily constrained by (a) the size of the prescribed burn, (b) the presence of active control lines or roads, (c) time since fire, and (d) weather during the encounter. Conclusions: We introduce a novel measure of barrier effectiveness and highlight the importance of thoughtful land management under ongoing climatic change. Implications: The simplicity of our proposed method is not limited to prescribed burns but can be used to measure the effectiveness of any barrier–wildfire encounter.

Background: Wildfires increasingly threaten communities at the wildland–urban interface, where effective garden management is crucial for reducing house loss. Aims: To understand barriers and opportunities for implementing garden wildfire prevention strategies by examining how residents’ risk perceptions align with assessed hazards and exploring factors influencing garden management decisions. Methods: We conducted a multi-modal study of 23 homeowners in Greater Hobart, Tasmania, Australia, combining quantitative survey, qualitative interviews, mapping exercises and photo-elicitation. Gardens were classified into risk categories based on biophysical assessments of both garden and landscape fire hazards, and the social data were analysed according to this framework. Key results: Significant discrepancies existed between perceived and actual hazards, particularly in zones closest to houses (0–1.5 m). While participants recognised landscape-level fire risks, they underestimated hazards in their own gardens and focused on plant flammability rather than spatial arrangement. Personalised garden hazard assessment reports effectively motivated change, especially among residents in high landscape-risk areas. Implementation barriers included knowledge gaps, resource constraints and emotional attachment to garden elements. Conclusions: Garden fire risk reduction requires flexible frameworks that respect resident values while emphasising critical near-house zones. Implications: Future interventions should combine property-specific assessments with community-based support systems to bridge the gap between awareness and implementation of garden safety measures.

With large wildfires becoming more frequent^1,2, we must rapidly learn how megafires impact biodiversity to prioritize mitigation and improve policy. A key challenge is to discover how interactions among fire-regime components, drought and land tenure shape wildfire impacts. The globally unprecedented^3,4 2019–2020 Australian megafires burnt more than 10 million hectares⁵, prompting major investment in biodiversity monitoring. Collated data include responses of more than 2,000 taxa, providing an unparalleled opportunity to quantify how megafires affect biodiversity. We reveal that the largest effects on plants and animals were in areas with frequent or recent past fires and within extensively burnt areas. Areas burnt at high severity, outside protected areas or under extreme drought also had larger effects. The effects included declines and increases after fire, with the largest responses in rainforests and by mammals. Our results implicate species interactions, dispersal and extent of in situ survival as mechanisms underlying fire responses. Building wildfire resilience into these ecosystems depends on reducing fire recurrence, including with rapid wildfire suppression in areas frequently burnt. Defending wet ecosystems, expanding protected areas and considering localized drought could also contribute. While these countermeasures can help mitigate the impacts of more frequent megafires, reversing anthropogenic climate change remains the urgent broad-scale solution.

Fire regimes have shaped extant vegetation communities, and subsequently fuel arrays, in fire-prone landscapes. Understanding how resilient fuel arrays are to fire regime attributes will be key for future fire management actions, given global fire regime shifts. We use a network of 63-field sites across the Sydney Basin Bioregion (Australia) to quantify how fire interval (short: last three fires 10 years apart) and severity (low: understorey canopy scorched, high: understorey and overstorey canopy scorched), impacted fuel attribute values 2.5 years after Australia’s 2019–2020 Black Summer fires. Tree bark fuel hazard, herbaceous (near-surface fuels; grasses, sedges <50 cm height) fuel hazard, and ground litter (surface fuels) fuel cover and load were higher in areas burned by low- rather than high-severity fire. Conversely, midstorey (elevated fuels: shrubs, trees 50 cm–200 m in height) fuel cover and hazard were higher in areas burned by high- rather than low-severity fire. Elevated fuel cover, vertical connectivity, height and fuel hazard were also higher at long rather than short fire intervals. Our results provide strong evidence that fire regimes rearrange fuel arrays in the years following fire, which suggests that future fire regime shifts may alter fuel states, with important implications for fuel and fire management.

Landscape fires emit smoke that contains particulate matter (PM) that can be harmful to human health. Prescribed fires or hazard reduction burns (HRBs) and wildfires can substantially reduce air quality in populated areas. While HRBs reduce the size and PM output of future wildfires, they also produce PM. There is a critical question of whether conducting HRBs adds to or reduces the total PM (prescribed + wildfire PM) exposure of populations, which has important community health implications. We modelled mean 24 h PM_2.5 in Sydney from fire type, 24 h active regional fire area and weather predictors. We compared HRB and wildfire area effects via an interaction between fire area and fire type, and we found that a non-linear effect of fire area was most appropriate. We conducted a trade-off analysis by using the model to predict increased HRB area scenarios and calculated the number of HRB and wildfire days with ‘Fair’ or worse air quality under each scenario. Regional HRBs and wildfire areas had similar effects on PM_2.5 in Sydney. Increasing regional HRB area produced substantial increases in HRB exceedance days (>12.5 µgm⁻³) in Sydney but only a small reduction in wildfire exceedance days. Our results indicate that small fires in the region have a higher per-hectare impact on PM levels in Sydney, and consequently, increasing regional HRB area would result in more poor air quality days overall (HRB + wildfire days) in Sydney.

In the spring and summer of 2019–2020, the ‘Black Summer’ bushfires burned more than 97 000 km² of predominantly Eucalyptus dominated forest habitat in eastern Australia. The Black Summer bushfires prompted great concern that many species had been imperilled by the fires. Here, we investigate the effects that fire severity had on the habitat and abundance of a cool climate lizard Eulamprus tympanum that was identified as a species of concern because 37% of its habitat was burnt in the Black Summer bushfires. We quantified habitat structure and the abundance of E. tympanum at sites which were unburnt, burnt at low severity and at high severity 10, 15 and 23 months after the fires. Our classification of fire severity based on scorch height and canopy status corresponded well with the Australian Government Google Earth Engine Burnt Area Map (AUS GEEBAM) fire severity layer. Ten months after the fires, sites burnt at high severity had less canopy cover, more bare ground and less fine fuel than sites burnt at low severity or unburnt sites. The abundance of E. tympanum varied with survey occasion and was greatest during the warmest sampling period and lowest during the coolest sampling period. The abundance of E. tympanum was consistently lower on sites burnt at high severity than sites burnt at low severity or unburnt sites. Our findings show that higher severity fires had a greater effect on E. tympanum than low severity fires. Our results suggest that E. tympanum were likely to have persisted in burnt sites, with populations in low severity and unburnt sites facilitating population recovery in areas burnt at high severity. Our results also suggest that wildfire impacts on E. tympanum populations will increase because the frequency and extent of severe fires are expected to increase due to climate change.