Abstract
Destructive wildfire disasters are escalating globally, challenging existing fire management paradigms. The establishment of defensible space around homes in wildland and rural urban interfaces can help to reduce the risk of house loss and provide a safe area for residents and firefighters to defend the property from wildfire. Although defensible space is a well-established concept in fire management, it has received surprisingly limited scientific discussion. Here we reviewed guidelines on the creation of defensible space from Africa, Europe, North America, South America, and Oceania. We developed a conceptual model of defensible space framed around the key recommended approaches to mitigate fire attack mechanisms, which address fuel types, amount, and spatial distribution. We found that zonation within the defensible space is commonly recommended; reduction (or removal) of all fuels, and particularly dead plant material, is usually suggested in close ( < 1.5 m; Fuel-free zone) proximity to a house. Conversely, in an intermediate space (1.5–10 m; Open zone), guidelines focus predominantly on minimizing fuel horizontal and vertical connectivity. Finally, in the outer part of the garden (10–30 m; Tree zone) trees can provide canopy shielding from ember attack and radiant energy, but management of on-ground fuel is still recommended. Evidence from the scientific literature broadly supported these defensible space design elements, although many studies were highly localised. Further empirical and modelling research is required to identify optimal zonation surrounding houses, and to better understand how garden structure, species composition and moisture status affects risk of ignition from embers, radiant heat, and flames.
Similar content being viewed by others
Introduction
Anthropogenic environmental changes are altering the global frequency and severity of wildfires. Weed proliferation, land abandonment, and fire suppression have increased fuel loads leading to more intense fires, while anthropogenic climate change has increased the length of fire seasons and the occurrence of extremely dangerous fire weather1,2,3,4,5,6,7, even for vegetation types not historically fire prone8. Such fire regime changes pose threats to human communities and ecosystems2, particularly in the Wildland-Urban and Rural-Urban Interface (WUI and RUI respectively, and WRUI henceforth), where suburban and semi-rural communities interface or are intermixed with natural vegetation9,10,11,12,13,14,15. Population density is typically low, although with major geographic differences10. A compounding factor is that WRUI areas have a high frequency of human-ignited fires16,17 making these settings a key locus for house loss disasters18. For instance, it has been estimated that in Australia the majority of house loss typically occurs within 100 m from natural vegetation19.
Because the natural and anthropogenic aspects of the WRUI are tightly interwoven, wildfire risk management is extraordinarily complicated, involving biophysical and socio-economic dimensions that impinge on wildfire prevention, preparation, and suppression strategies associated with limiting fire spread and intensity from surrounding wildlands whilst mitigating property fire risk20,21,22. How to best manage wildfire risk of at the WRUI has been debated for decades23,24, with proposed solutions including urban design25, early fire detection26, aerial suppression through rapid attack27,28, and wildland fuel treatments. Yet, no consensus or demonstrated effective strategy has been achieved. Solving this problem is becoming urgent because of the observed expansion of the WRUI29,30,31,32, which has led to increased occurrence of disastrous fires, surging firefighting costs9,33, and more costly home insurance causing an epidemic of under-insurance34.
Current approaches to managing fire risk on the WRUI carry a range of constraints and adverse side-effects. Aggressive fire suppression can create a ‘fire suppression paradox’ that encourages urban settlement in hazardous landscape settings35, and can reinforce negative feedbacks through vegetation change and fuel build-up, leading to more extensive and destructive bushfires36. The most prominent wildland fuel treatment is prescribed burning, which involves fires intentionally set under favourable conditions to reduce fuel loads in wildlands. There is, however, mounting evidence that the approach has a modest protective effect for house loss unless it is in close proximity to urban areas37, but problematically this necessitates careful, costly and oftentimes legally challenging coordination of different landowners38,39. Prescribed burning also has many downsides including: being ineffective in extreme fire weather conditions, which are increasing in frequency due to climate change40; having a risk of escaping control41; causing smoke pollution and substantial health harms42; and potential loss of biodiversity43. Further, there is no clear social or community preference for a specific type of intervention to reduce wildland fuels, with individual opinions affected by personal values and knowledge of local ecosystems44,45,46,47. Finally, there is emerging evidence that in some highly flammable environments, such as Australian eucalypt forests, a focus on long-term wildland fuel management might be legally, financially, and ecologically unsustainable48.
A commonly officially recommended, yet comparatively less-researched option in mitigating fire risk in the WRUI involves modifying urban areas to increase their ability to survive bushfires by focusing on building construction and design, as well as creating low flammability zones surrounding houses, known as ‘defensible spaces’49. The US Forest Service defines the defensible space as the area surrounding a house where the space has been modified to reduce the threat of wildfires by removing, reducing, and replacing elements of the space that increase fire hazard (USDA Forest Service). Models based on post-fire assessments revealed that garden characteristics, particularly vegetation type and cover near the house50,51,52, as well as presence of non-vegetative fuels53,54, affect the likelihood of house loss. In one case, they were found to be more important than building characteristics in determining house survival55. Creating and maintaining effective defensible space means that residents are more likely to be able to stay and defend the property and that it is safer for firefighters to engage with a house fire without fear of entrapment56. Homes are also more likely to withstand a fire if defended57.
The underlying logic and biophysical basis of definitions of defensible space has received surprisingly limited investigation. Reviews on the defensible space are scarce and focus predominantly on house design, construction building regulations58,59, or framing it as a core component mitigation on the broader WRUI60. What is lacking is a synoptic overview of defensible design principles that can lead to a more theoretical understanding of defensible space framed in terms of physical principles that affect wildfire occurrence and behaviour, based on evidence of the importance of key variables that shape these physical processes.
Here we proposed a conceptual model of defensible space based on the main mechanisms of wildfire behaviour and the key wildfire mitigation strategies, the latter obtained from a review of the guidelines for the establishment of defensible space. To identify consistent themes across a wide range of geographic settings, we searched guidelines written in (or translated in) English, French, Italian, or Spanish, using the keywords ‘wildfire defensible space’, ‘bushfire defensible space’, ‘wildfire home preparation’, ‘espace défendable incendies de forêt’, ‘incendi spazio difendibile’, ‘espacio de autoprotección’. Since many of the guidelines are considered grey literature, we did not limit our search to academic search engines (Web of Science and Google Scholar) but also included a general search engine (Google Search), in which we included as search term country-specific domains of countries with high fire activity and presence of WRUI (Fig. 1). Results were then screened to include only documentation that explicitly addressed defensible space design. We collated information from 68 guidelines from Africa (South Africa), Europe (France, Greece, Italy, Portugal, and Spain), North America (Canada and United States of America), Oceania (Australia and New Zealand), and South America (Argentina and Chile) (Fig. 1). Guideline sources included federal and state government departments or organizations, local councils, universities, and independent organizations (e.g., Australian College of Architects). A full list is available in Table S1 in Supporting Information. Drawing on these guidelines, we discussed the core elements of the defensible space aimed at maximising its effectiveness in relation to wildfire threats. For each component of this framework, we then presented existing evidence from the scientific literature, to identify concordance of guideline design elements with empirical research as well as identifying knowledge gaps. Such a framework is an essential step to effectively quantify defensible space on the WRUI and support the creation of fire-resilient landscapes61.
Bushfire attack mechanisms
The concept of wildfire defensible space hinges on its capacity to stop radiative and convective energy crossing a critical heat flux threshold and causing a house fire62. Energy transfer can occur through three mechanisms: direct flame contact, radiative heat, and firebrand attack (Fig. 2).
Direct flame contact represents a high risk, but only in proximity to the house. Radiant heat constitutes a high risk near the house, but quickly declines as the heat source is located away from the house. Conversely, the risk caused by firebrand attacks only slightly decline with distance.
Direct flame contact includes both convective and radiant energy and is potentially the most hazardous wildfire house-loss mechanism, as it has the highest heat fluxes, with temperature reaching 1,000°C63,64. By providing a source of flames (piloted ignition), it also lowers the temperature required to ignite fuel65. It is, however, limited by the ability of flames to reach the house62; protective factors thus work by separating wildland and domestic fuels. Post-fire assessments show that proximate flame contact is an important, albeit not necessarily the predominant, cause of house ignition53,66,67.
Radiant heat, defined as electromagnetic radiation emitted from thermally hot bodies, can cause structure ignition if sufficiently intense68. For instance, it can cause window breakage69, thus exposing the interior of the house to flames and firebrands. Field experiments showed that radiant heat fluxes generated by wildfires can reach up to 300 kW/m270, well above the threshold of 13 kW/m2, which has been found to be sufficient to cause wooden building ignition71,72. As such, the Australian Bushfire Attack Levels that are used for determining the building specifications of homes in bushfire prone areas are based around assessed radiant energy loads (kw m−1). As radiant heat is proportional to the inverse of the square of the distance from the source68, its threat to the house and people defending it diminishes progressively as the heat source is located away from the house (Fig. 2). However, radiant heat is a common cause of bushfire fatalities73, as skin burns and blistering can occur within a few seconds of exposure to heat fluxes well below structural ignition thresholds74.
Firebrands, the third bushfire attack mechanism, are airborne flaming or smouldering fuel particles, lifted by the plume of fire gases and carried horizontally by winds. Firebrands can impact properties i) directly, by setting on fire structures and vegetation within the defensible space, and ii) indirectly, by creating additional fires (spot fires) ahead of the main fire front75. They can travel up to more than 30 km from the main fire front76, although an analysis of 4000 spot fires in Australia found that only 10% of firebrands reached beyond 1 km77. As such, they are widely recognised as a common cause of house loss at the WRUI54,67.
A conceptual model of wildfire defensible space
The sourced guidelines for the creation of defensible space translate this physical concepts into actionable recommendations that can be grouped in three key and closely related fuel characteristics: type, amount, and spatial distribution. Fuel type determines ignitability from embers, shapes energy release and hence convective and radiative energy, as well as fire behaviour including rate of spread. Fuel amount (or fuel load) affects total energy release, while fuel spatial distribution influences the probability of flame contact with a house or spread between vegetation patches, firebrand density, and radiant heat load should the fuel ignite. Based on this framework, we grouped specific guideline recommendations according with the risk factor they address (fuel type, amount, or spatial distribution; Tables 1, 2 and S2 in Supplementary Information) and reviewed the concordance with evidence from the scientific literature.
Fuel amount
The concept of modifying fuel loads surrounding homes is central to all guidelines for the creation of defensible space. When guidelines recommend a specific defensible space extent, they typically focus on a 30–40 m radius from the edge of the building or up to the property line, whichever is shorter, particularly in Africa, North America, and South America (Fig. 3; Table 1). In Europe, particularly in Portugal and France, the recommended distance can be up to 50 m78,79. When the minimum distance is shorter than 30 m, guidelines often recommend consideration of slope angle and surrounding vegetation type, leading to larger recommended defensible space if not on flat ground (e.g., France79, Portugal78, Italy80, Canada81, United States82, and Australia83; full list available in Table S2 in Supplementary Information). This is because fire usually propagates faster uphill due to the increased amount of fuel exposed to radiant heat and direct flame contact84,85, although in some settings extreme fires can progress downslope (e.g., driven by Foehn winds86) or along a valley or lee slope (i.e., vorticity-driven lateral spread87). The main strategy to reduce fuel amount involves thinning vegetation, removing dead plant material, keeping lawn grass short, and reducing canopy cover (Table 1). In New South Wales (Australia), guidelines recommend not exceeding 15% of canopy cover across the whole defensible space, with lower values (10%) for shrubs88 (Table 1, Table S2 in Supplementary Information). More specific guidelines on fuel amount are usually provided for each section of the defensible space (see ‘Fuel spatial distribution’).
For those guidelines that address individual zones, the proportion of guidelines suggesting each specific distance is shown.
Overall, the scientific literature supports the recommended extent and general characteristics of the defensible space, although the evidence is relatively scarce. Post-fire geospatial analyses of house loss have shown a statistically significant effect of the characteristics of gardens surrounding houses up to 30–40 m57,89. Similarly, models on radiant heat as a cause of house ignition suggested that the threshold distance ranges between 20 m and 40 m depending on the model used71,90,91. Finally, a study on crown fires in lodgepole pine (Pinus contorta) forests measured the maximum flame length to be approximately 30 m92. Research that considered the effect of canopy cover within the whole defensible space found vegetation cover to be an important predictors of house loss57,89,93, with every 10% reduction in vegetation cover around houses (if remnant Australian native vegetation, which is typically highly flammable) associated with a reduction in the likelihood of house loss of approximately 5%51. This combined evidence supports the notion that the overall extent of the defensible space recommended in guidelines can contribute to mitigate fire risk, although caution must be exercised in generalising the findings of localised studies.
Fuel type
Typically, defensible spaces include gardens. As such, the most common fuels are living and dead phytomass (live plants and leaf litter, fallen branches, dead grasses and forbs). Plant flammability, broadly defined as the capacity of plant material to ignite and sustain a fire, is typically represented by four axes: ignitability (ability of a plant to ignite), combustibility (heath released), sustainability (burn duration), and consumability (biomass combusted)94. These parameters vary across plant species due to leaf moisture content, leaf morphological and chemical traits (e.g., chemical composition, particularly oils, leaf type and arrangement), plant architecture, and bark characteristics95. There are numerous lists on the likely flammability of plant species that are typically grown in gardens, either based on knowledge of local species or plant traits, and the majority of guidelines recommend selecting low-flammability species across the whole defensible space (Fig. 4a; Table 1). However, those lists are not always validated by empirical studies. Whilst a study of native and non-native plants in New Zealand found a reasonable agreement between expert opinion and laboratory flammability assessments96, other studies could not validate all plant recommendations, which can also be conflicting across different guidelines97. Further, although research on plant flammability has been conducted for decades95,98, and some of those studies specifically targeted native and exotic plants at the WRUI99,100,101, the variety of assessment methods adopted limits cross-study comparisons102.
Topics are summarised (a) across the whole defensible space, and within the (b) Fuel-free zone, (c) Open zone, and (d) Trees zone. For each zone (and for the whole defensible space), the proportion of guidelines mentioning each specific topic is shown.
Ground cover also affects garden flammability. Similarly to plant flammability, the flammability of the litter that accumulates underneath plants is also influenced by species characteristics103. Additionally, the spreading of organic materials (e.g., pine bark, wood chips, straw, cardboard that is generally known as ‘mulch’) is typically used in gardening practices to reduce evaporation from soil and increase plant water availability104, as well as controlling weeds, improving soil health and garden aesthetics105. Because of the potential flammability of even the most ignition-resistant organic mulch, guidelines recommend avoiding organic mulch and instead relying on non-flammable material such as pebbles and earthen surfaces across the defensible space (Fig. 4a, Table 1). Indeed, research showed that most common types of organic mulch are highly flammable and contribute to fuel horizontal continuity106,107,108,109,110. Even the least flammable types of organic mulch can provide receptive fuel beds under continuous firebrand shower111.
Fences and gates are important fuel elements that can positively and negatively affect garden flammability. Most guidelines recommend choosing fences made of low-flammability (e.g., hardwood) or preferably non-combustible (e.g., steel) material (Fig. 4a; Table 1), particularly if the fence is close to the house or connected to other flammable objects (e.g., mulch, weed beds, trellis). Post-fire assessments have confirmed that fences made from flammable materials (e.g., wood and plastic) can be ignited by firebrands and sustain and spread fire in the garden112, especially if poorly maintained66,93. Conversely, fences made of non-flammable material can shield the house from radiant heat113. Other features of gardens such as outdoor mats, outdoor furniture, woodpiles, gas barbeques materials and garden sheds and gardening supplies (fertiliser, weedkiller) are also recognised as ‘fuel’.
Within the defensible space, irrigation can mitigate fire intensity by creating a cool moist microclimate that hinders fire propagation114 and reduces plant flammability115. Some guidelines mention the use sprinklers in the defensible space58, particularly if they are automatically activated through smoke detectors or heat sensors116, as they can also provide active defence against bushfires, effectively protecting structures as well as vegetation117. However, installation costs and ongoing maintenance117, as well as their reliance on large amounts of water to be effective118, can lead to low adoption rates119. As such, they are best suited for retrofitting existing spaces, while newly designed areas should instead rely on passive defence strategies such as garden characteristics120.
Fuel spatial distribution
The defensible space is often divided into zones with increasing distance away from the home, each associated with specific amounts, arrangements, and type of living and non-living fuels. The majority of guidelines including zones, and particularly in North America, delineate them as: (a) an immediate zone within 1.5 m from the house (henceforth Fuel-free zone), (b) an intermediate zone between 1.5 and 10 m from the house (henceforth Open zone), and (c) an extended zone, between 10 and 30 m (henceforth Tree zone) (Fig. 3; Tables 2–4). Australian guidelines combine the Fuel-free and Open zones into an ‘Inner zone’. Ideally, the Fuel-free zone should have no dead plant material or any combustible objects/material, particularly under the house or deck, and vegetation should be avoided or limited to short lawn grass and possibly succulents, to reduce risk of direct flame and ember ignitions.(Fig. 4b; Table 2).
By contrast, in the Open zone the key focus is to manage vegetation and non-vegetated fuels to interrupt horizontal and vertical connectivity, thus minimizing fire spread towards the house or at least limiting it to low intensity surface fires (Fig. 4c; Table 3). To ensure horizontal fuel disconnection, guidelines recommend managing lawn grass length, distance of shrub patches between each other, and use of paths made of non-flammable material (e.g., gravel, earth, paving stones) to break fuel continuity. Vertical connectivity is avoided by pruning the lowest tree branches to separate them from the fuels underneath and carefully considering all possible connections between vegetated and non-vegetated fuels (e.g., mulch to fences, litter and bark to shrubs). When specific information on minimum horizontal and vertical separation between fuels is provided, values tend to vary between guidelines. For instance, the minimum horizontal distance between crowns can range between 2 m and 10 m and the recommended tree distance from the house between 3 m and 10 m, while the minimum vertical distance between lower adult tree branches and underneath fuels is usually 2 m to 3 m (Table 3; Table S2 in Supporting Information). Despite the focus on spatial arrangement, fuel load should also be limited in the Open zone, especially dead plant material and flammable objects, and vegetation cover should be minimized (Table 3).
Finally, in the Tree zone the primary aim of fuel management is to retain trees to absorb radiant energy and capture embers, whilst reducing surface fuel loads to limit the intensity and spread of fires, and risk of crown fires (Fig. 4d). Possibly because of its distance from the house and the lower threat that fuels in the Tree Zone represent, guidelines tend to be generic or, when specific, they are subject to substantial variation. For instance, recommended maximum canopy cover vary between 15%121 and 50%78 and several guidelines in North America, Europe, and Oceania still recommend specific minimum horizontal and vertical distances between fuels (Table 4; Fig. 4d; Table S2 in Supporting Information).
Albeit scarce, evidence from the scientific literature does associate vegetation structure in gardens with risk of house loss. For instance, trees and shrubs organized in distinct patches have been linked with lower house-loss risk, especially if positioned in a downwind direction from which wildfires arrive122. Similarly, models on the effect of planting arrangement on fire behaviour in urban landscapes concluded that horizontal and vertical fuel separation translates to lower flame heights and slower rate of spread123.
No study explicitly evaluated the effectiveness of the recommended zone sizes and their respective characteristics. Some indirect support can, however, be found in the scientific literature. Post-fire house loss studies have found that the presence of vegetation in contact with the house increased the chances of house destruction50,89 Research conducted across a range of vegetation types (grassland, conifer forest, and brush) in the United States showed typical flame length of surface or brush fires to be 1–2 m92. These studies indirectly support the establishment of a Fuel-free zone to make the immediate perimeter ( < 1.5 m) of houses as fuel free as possible. In respect to the Open zone, an assessment of house loss in California showed that, in regions where the size of defensible space explained at least 1% of the variation in house survival, the average defensible space of the structures that survived the fire was 9.7 m124. Further, experimental crown fires have identified the critical structure-to-flame distance that would result in wall ignition as 10 m71,90, particularly if the fire front length is lower than 100 m91. Similarly, flame length in dry eucalypt forests in south-west Western Australia was estimated to be 1–14 m125.This suggests that the size of the Open zone (1.5–10 m from the house) is possibly adequate to address the risk of direct flame contact (Fig. 5). There is limited scientific literature about the Tree zone. Although not focused on gardens, research on the influence of surface and near-surface fuels showed that their quantity, composition, and arrangement affect fire behaviour126,127, supporting guidelines recommending management of surface and near-surface fuels in the Tree zone. Vegetation in the Tree zone can effectively shield the house from firebrand attack if made of low-flammability species55,122, suggesting that tree retention can help to reduce risks associated with firebrand attack.
The left side shows an effective defensible space, with overall low canopy cover, nicely green plants and grass, no vegetation in proximity of the building, and trees and shrubs organised in distinct patches which are not interconnected. With this design a fire approaching from the surrounding landscape would not encroach within the defensible space and, if individual shrubs/trees were to be lit by firebrands, fire would not easily propagate. The right side shows the opposite, where high canopy cover and connectivity facilitate fire spread from the landscape all the way to the house.
Discussion
Understanding defensible space is a critical frontier in wildfire adaptation as it provides homeowners a relatively low-cost option to increase the likely survival of homes and lives, compared to the difficulty and expense of retrofitting structures to withstand wildfires128.
The concept of defensible space is widely promoted by fire managers and is based on logical physical principles to reduce the threat of house loss by minimizing ember ignitions, radiative heat, and flame contact (Fig. 5). Yet, there is surprisingly limited empirical evaluation of defensible space in general and none on the effectiveness of its specific zones, with nearly all studies based on post-fire assessments using geospatial or ground survey techniques50,54,57,66. This reliance on inferential studies reflects the obvious practical difficulties of understanding field experiments involving uncontrollable wildfires. Modelling the effect of different garden designs on house loss is a profitable, and little explored, research avenue. To be realistic, however, modelling exercised would require much more field data on how basic parameters such as ember density and radiant heat fields are modified by vegetation and garden design129.
When clear information from the scientific literature is missing, or consists in few, highly localised studies, guidelines tend to provide more generic recommendations. For instance, the lack of data on the interplay between canopy cover, plant arrangement, and selected species123 results in most guidelines simply mentioning the importance of spacing between clusters of plants in the Open zone; when more specific recommendations were given, there was inconsistency across guidelines. While this could reflect biogeographic and environmental differences, the difficulty in reconstructing how specific thresholds are determined suggests that guidelines could benefit from more information from rigorous empirical studies. Recent quantitative assessments of plant flammability are a clear example of how the existing flammability lists can be tested and improved upon96. Similarly, the increasing availability of high-resolution remote sensing data, such as satellite imagery and LiDAR data, provides the important opportunity to undertake assessments of defensible space on wide geographic scales130,131. This will allow to include the characteristics of each zone in post-fire house-loss studies, and thus test the influence of zone extent and characteristics on house survival. In the meanwhile, we argue that implementing a zonation-based approach, which broadly aligns with wildfire physical characteristics, can support the creation of effective defensible space while minimizing maintenance costs and garden constraints, since the stricter guidelines (e.g., minimizing all fuels in the Fuel-Free Zone or ensuring spatial separation in the Open zone) are limited to the portion of the garden closer to the house.
Well-designed defensible space can provide high amenity and promote biodiversity in urban environments on the WRUI. Gardens have been shown to benefit plant and animal biodiversity by improving habitat connectivity and providing habitat for some endangered species132,133,134,135,136, although their typically high plant species richness is usually driven by exotic species, rather than native137,138,139,140. Encouraging the use of the local native flora in gardens might have biodiversity benefits but could increase fire risk depending on the flammability of the chosen plant species. For instance, exotic species were found to be of higher flammability than native plants in Patagonian gardens at the WRUI99. Conversely, in Australia exotic plants in gardens at the WRUI are generally less flammable than native species, although some low-flammability native species were also identified100. This suggests that future laboratory assessments might be able to pinpoint native low-flammability options even from typically fire-prone environments. Species selection must also account for current and future local environmental characteristics, particularly in respect to drought tolerance141. Garden layout can also contribute to promote local biodiversity without necessarily increasing fire risk. For example, this can be obtained by avoiding needless clearing of trees and ground cover in zones where guidelines are less strict (such as in the Tree zone) or spatially organising plants to minimize fire spread (Open zone). Well-designed, biodiverse defensible spaces have amenity and practical benefits beyond biodiversity conservation and fire safety, such as promoting urban-heat mitigation123 and improving residents’ physical and mental wellbeing142,143. Whilst gardens are traditionally based on utilitarian or aesthetic principles140, wildlife-friendly gardens are increasingly valued143,144. Yet, the limited knowledge base about wildlife-friendly gardens140 limits the ability to design biodiverse and fire-wise gardens.
It is important to acknowledge that defensible space is but one component in mitigating the risk of house loss. In addition to wildland fuel management, particularly in close proximity of property boundaries, and creation of defensible space, the other major factor is house design124. These last two components are fundamentally interconnected because a well-designed home may be lost to wildfire if fuel management in the defensible space is insufficient, and a poorly designed house may be still vulnerable to destruction from ember attack even if provided appropriate defensible space. An additional consideration is that the concept of defensible space also includes provision of a safe space for residents to stay with their properties and extinguish spot fires caused by firebrands. The dual objective of protecting property from fires and providing a refuge for residents are typically conflated, despite having different requirements, for example in radiative heat load74. The risk of loss of life has led to call for the installation of private fire shelters as a safe place of last resort145. Such private fire shelters increase the opportunity for residents to stay and defend properly designed and maintained homes and gardens, although at possibly prohibitive costs.
Finally, a critical field of inquiry concerns the social acceptability of defensible space, and the willingness of residents to pay for the establishment and maintenance of low flammability gardens. This is a crucial step, since the compliance to local guidelines remains a predominantly voluntary process, although an increasing number of countries/states have implemented legal requirements for the creation of defensible space146,147,148,149,150 and calls have been made to enforce legal obligations in fire-prone areas across Europe151. While there can be a positive correlation between wildfire information and mitigation measures152, residents’ awareness of fire risk does not always translate into adaptive action153. Understanding the main sociodemographic and economic barriers that limit the adoption of defensible space guidelines and presenting solutions that account for people’s preference and focus on community engagement is pivotal to support more fire-adapted communities154. Further interdisciplinary research into defensible space is thus an essential step in the broader adaptation pathway for humans to coexist with wildfires on the WRUI.
Data availability
No datasets were generated or analysed during the current study.
References
Khorshidi, M. S. et al. Increasing concurrence of wildfire drivers tripled megafire critical danger days in Southern California between1982 and 2018. Environ. Res. Lett. 15, 104002 (2020).
Bowman, D. M. J. S. et al. Vegetation fires in the Anthropocene. Nat. Rev. Earth Environ. 1, 500–515 (2020).
Palm, E. C. et al. Increasing fire frequency and severity will increase habitat loss for a boreal forest indicator species. Ecol. Appl. 32, e2549 (2022).
Kelly, L. T. et al. Understanding fire regimes for a better Anthropocene. Ann. Rev. Environ. Res. 48, null (2023).
Moritz, M. A. et al. Climate change and disruptions to global fire activity. Ecosphere 3, art49 (2012).
Jolly, W. M. et al. Climate-induced variations in global wildfire danger from 1979 to 2013. Nat. Commun. 6, 7537 (2015).
Mantero, G. et al. The influence of land abandonment on forest disturbance regimes: a global review. Landsc. Ecol. 35, 2723–2744 (2020).
Pearce, H. The 2017 Port Hills wildfires—A window into New Zealand’s fire future. Austr. J. Disaster Trauma Stud. 22, 35–50 (2018).
Radeloff, V. C. et al. Rapid growth of the US wildland-urban interface raises wildfire risk. Proc. Natl. Acad. Sci. 115, 3314–3319 (2018).
Schug, F. et al. The global wildland–urban interface. Nature 621, 94–99 (2023).
Chappaz, F. & Ganteaume, A. Role of land-cover and WUI types on spatio-temporal dynamics of fires in the French Mediterranean area. Risk Anal. 43, 1032–1057 (2023).
Gill, A. M. & Stephens, S. L. Scientific and social challenges for the management of fire-prone wildland–urban interfaces. Environ. Res. Lett. 4, 034014 (2009).
Alexandre, P. M. et al. The relative impacts of vegetation, topography and spatial arrangement on building loss to wildfires in case studies of California and Colorado. Landsc. Ecol. 31, 415–430 (2016).
Price, O. & Bradstock, R. Landscape scale influences of forest area and housing density on house loss in the 2009 Victorian bushfires. PLOS ONE 8, e73421 (2013).
Chen, B. et al. Wildfire risk for global wildland–urban interface areas. Nat. Sustain. https://doi.org/10.1038/s41893-024-01291-0 (2024).
Syphard, A. D. et al. Human influence on California fire regimes. Ecol. Appl. 17, 1388–1402 (2007).
Price, O. F. & Bradstock, R. A. The spatial domain of wildfire risk and response in the wildland urban interface in Sydney, Australia. Nat. Hazards Earth Syst. Sci. 13, 3385–3393 (2013).
Kramer, H. A., Mockrin, M. H., Alexandre, P. M., Stewart, S. I. & Radeloff, V. C. Where wildfires destroy buildings in the US relative to the wildland–urban interface and national fire outreach programs. Int. J. Wildland Fire 27, 329–341 (2018).
Chen, K. & McAneney, J. Bushfire penetration into urban areas in Australia: A spatial analysis. (Bushfire CRC, Melbourne, VIC, 2010).
Ganteaume, A., Barbero, R., Jappiot, M. & Maillé, E. Understanding future changes to fires in southern Europe and their impacts on the wildland-urban interface. J. Safety Sc. Resilience 2, 20–29 (2021).
Jenerette, G. D. et al. An expanded framework for wildland–urban interfaces and their management. Front. Ecol. Environ. 20, 516–523 (2022).
Calkin, D. E., Cohen, J. D., Finney, M. A. & Thompson, M. P. How risk management can prevent future wildfire disasters in the wildland-urban interface. Proc. Natl. Acad. Sci. 111, 746–751 (2014).
Dannenberg, M. R. Fire protection in the wildland/urban interface: a Montana viewpoint Master of Forestry thesis, The University of Montana, (1983).
Davis, J. B. The wildland-urban interface: paradise or battleground? J. Forestry 88, 26–31 (1990).
Norman, B., Newman, P. & Steffen, W. Apocalypse now: Australian bushfires and the future of urban settlements. npj Urb. Sustain. 1, 2 (2021).
Partheepan, S., Sanati, F. & Hassan, J. Autonomous unmanned aerial vehicles in bushfire management: challenges and opportunities. Drones 7, 47 (2023).
Plucinski, M. P., McCarthy, G. J., Hollis, J. J. & Gould, J. S. The effect of aerial suppression on the containment time of Australian wildfires estimated by fire management personnel. Int. J. Wildland Fire 21, 219–229 (2012).
Alsammak, I. L. H., Mahmoud, M. A., Aris, H., AlKilabi, M. & Mahdi, M. N. The use of swarms of unmanned aerial vehicles in mitigating area coverage challenges of forest-fire-extinguishing activities: A systematic literature review. Forests 13, 811 (2022).
González-Ávila, S., López-Leiva, C., Bunce, R. G. H. & Elena-Rosselló, R. Changes and drivers in Spanish landscapes at the Rural-Urban Interface between 1956 and 2018. Sci. Tot. Environ. 714, 136858 (2020).
Kaim, D., Radeloff, V. C., Szwagrzyk, M., Dobosz, M. & Ostafin, K. Long-term changes of the Wildland–Urban Interface in the Polish Carpathians. ISPRS Int. J. Geo-Inform. 7, 137 (2018).
Theobald, D. M. & Romme, W. H. Expansion of the US wildland–urban interface. Landsc. Urban Plan. 83, 340–354 (2007).
Tonini, M., Parente, J. & Pereira, M. G. Global assessment of rural–urban interface in Portugal related to land cover changes. Nat. Hazards Earth Syst. Sci. 18, 1647–1664 (2018).
Clark, A. M. et al. The impact of residential development pattern on wildland fire suppression expenditures. Land Econ. 92, 656–678 (2016).
Booth, K. et al. House and contents underinsurance: Insights from bushfire-prone Australia. Int. J. Disaster Risk Reduction 80, 103209 (2022).
Ingalsbee, T. Whither the paradigm shift? Large wildland fires and the wildfire paradox offer opportunities for a new paradigm of ecological fire management. Int. J. Wildland Fire 26, 557–561 (2017).
Calkin, D. E., Thompson, M. P. & Finney, M. A. Negative consequences of positive feedbacks in US wildfire management. Forest Ecosyst. 2, 9 (2015).
Florec, V., Burton, M., Pannell, D., Kelso, J. & Milne, G. Where to prescribe burn: the costs and benefits of prescribed burning close to houses. Int. J. Wildland Fire 29, 440–458 (2020).
Fischer, A. P. Reducing hazardous fuels on nonindustrial private forests: Factors influencing landowner decisions. J. Forestry 109, 260–266 (2011).
Busby, G. M., Albers, H. J. & Montgomery, C. A. Wildfire risk management in a landscape with fragmented ownership and spatial interactions. Land Econ. 88, 496–517 (2012).
Clarke, H. et al. The 2019–2020 Australian forest fires are a harbinger of decreased prescribed burning effectiveness under rising extreme conditions. Sci. Rep. 12, 1–10 (2022).
Fernandes, P. M. & Botelho, H. S. A review of prescribed burning effectiveness in fire hazard reduction. Int. J. Wildland Fire 12, 117–128 (2003).
Borchers-Arriagada, N. et al. Smoke health costs and the calculus for wildfires fuel management: a modelling study. Lancet Planetary Health 5, e608–e619 (2021).
Bradshaw, S. D. et al. Understanding the long-term impact of prescribed burning in mediterranean-climate biodiversity hotspots, with a focus on south-western Australia. Int. J. Wildland Fire 27, 643–657 (2018).
Winter, G. J., Vogt, C. & Fried, J. S. Fuel treatments at the wildland-urban interface: Common concerns in diverse regions. J. Forestry 100, 15–21 (2002).
McWethy, D. B. et al. Rethinking resilience to wildfire. Nat. Sustain. 2, 797–804 (2019).
Ryan, R. L. The influence of landscape preference and environmental education on public attitudes toward wildfire management in the Northeast pine barrens (USA). Landsc. Urban Planning 107, 55–68 (2012).
Gill, N., Brennan-Horley, C. & Dun, O. 5. Investigating Residents’ Bushfire Hazard Mitigation and Amenity Values through Interviews, Qualitative Mapping, and Property Walks. Social Construct of Fuels in the Interface. 105–143 (2014).
Bradstock, R. A. et al. Wildfires, fuel treatment and risk mitigation in Australian eucalypt forests: Insights from landscape-scale simulation. J. Environ. Manag. 105, 66–75 (2012).
Syphard, A. D., Brennan, T. J. & Keeley, J. E. The importance of building construction materials relative to other factors affecting structure survival during wildfire. Int. J.Disaster Risk Reduc. 21, 140–147 (2017).
Penman, S. H., Price, O. F., Penman, T. D. & Bradstock, R. A. The role of defensible space on the likelihood of house impact from wildfires in forested landscapes of south eastern Australia. Int. J. Wildland Fire 28, 4–14 (2019).
Gibbons, P. et al. Land management practices associated with house loss in wildfires. PLOS ONE 7, e29212 (2012).
Ribeiro, L. M., Rodrigues, A., Lucas, D. & Viegas, D. X. The Impact on Structures of the Pedrógão Grande Fire Complex in June 2017 (Portugal). Fire 3, 57 (2020).
Quarles, S. et al. Lessons learned from Waldo Canyon: Fire Adapted Communities mitigation assessment team findings. (Fire Adapted Communities Coalition, USA, 2012).
Maranghides, A., McNamara, D., Mell, W., Trook, J. & Toman, B. A case study of a community affected by the Witch and Guejito Fires: Report# 2: Evaluating the effects of hazard mitigation actions on structure ignitions. (2013).
Vermina Plathner, F., Sjöström, J. & Granström, A. Garden structure is critical for building survival in northern forest fires – An analysis using large Swedish wildfires. Safety Sci. 157, 105928 (2023).
Kolden, C. A. & Henson, C. A socio-ecological approach to mitigating wildfire vulnerability in the wildland urban interface: A case study from the 2017 Thomas fire. Fire 2, 9 (2019).
Price, O. F., Whittaker, J., Gibbons, P. & Bradstock, R. Comprehensive examination of the determinants of damage to houses in two wildfires in eastern Australia in 2013. Fire 4, 44 (2021).
Intini, P., Ronchi, E., Gwynne, S. & Bénichou, N. Guidance on design and construction of the built environment against wildland urban interface fire hazard: A review. Fire Technol. 56, 1853–1883 (2020).
Hakes, R. S. P., Caton, S. E., Gorham, D. J. & Gollner, M. J. A review of pathways for building fire spread in the wildland urban interface part II: Response of components and systems and mitigation strategies in the United States. Fire Technol. 53, 475–515 (2017).
Taccaliti, F., Marzano, R., Bell, T. L. & Lingua, E. Wildland & urban interface: definition and physical fire risk mitigation measures, a aystematic review. Fire 6, 343 (2023).
Thacker, F. E. N., Ribau, M. C., Bartholomeus, H. & Stoof, C. R. What is a fire resilient landscape? Towards an integrated definition. Ambio 52, 1592–1602 (2023).
Babrauskas, V. Ignition handbook: principles and applications to fire safety engineering, fire investigation, risk management and forensic science. (Washington Fire Science Publishers, 2003).
Pastor, E. in Encyclopedia of wildfires and Wildland-Urban Interface (WUI) fires (ed Samuel L. Manzello) 1-7 (Springer International Publishing, 2019).
Sullivan, A. L., Ellis, P. F. & Knight, I. K. A review of radiant heat flux models used in bushfire applications. Int. J. Wildland Fire 12, 101–110 (2003).
Babrauskas, V. Minimum Values of Voltage, Current, or Power for the Ignition of Fire. Fire 5, 201 (2022).
Maranghides, A., McNamara, D., Vihnanek, R., Restaino, J. & Leland, C. A case study of a community affected by the Waldo fire. Event timeline and defensive actions. (2015).
Blanchi, R. & Leonard, J. Investigation of bushfire attack mechanisms resulting in house loss in the ACT bushfire 2003. (Bushfire CRC Report, 2005).
Mitchell, J. W. in Encyclopedia of wildfires and Wildland-Urban Interface (WUI) fires (ed Samuel L. Manzello) 1-6 (Springer International Publishing, 2018).
Babrauskas, V. Glass breakage in fires. Fire Science and Technology, Inc, 1–7, http://doctorfire.com/GlassBreak.pdf (2011).
Filkov, A. I. et al. A review of thermal exposure and fire spread mechanisms in large outdoor fires and the built environment. Fire Safety J. 140, 103871 (2023).
Cohen, J. D. Relating flame radiation to home ignition using modeling and experimental crown fires. Canadian J. Forest Res. 34, 1616–1626 (2004).
Standards Australia. AS3959-2009: Construction of buildings in bushfire prone areas. (SAI Global Limited, 2009).
Blanchi, R. et al. Environmental circumstances surrounding bushfire fatalities in Australia 1901–2011. Environ. Sci. Policy 37, 192–203 (2014).
Quintiere, J. G. (CRC Press, Taylor & Francis Group, 2017).
Babrauskas, V. in Encyclopedia of wildfires and Wildland-Urban Interface (WUI) fires (ed Samuel L. Manzello) 1–14 (Springer International Publishing, 2018).
Cruz, M. G. et al. Anatomy of a catastrophic wildfire: The Black Saturday Kilmore East fire in Victoria, Australia. Forest Ecol. Manag. 284, 269–285 (2012).
Storey, M. A., Price, O. F., Bradstock, R. A. & Sharples, J. J. Analysis of variation in distance, number, and distribution of spotting in southeast Australian wildfires. Fire 3, 10 (2020).
Portugal Wildfires. Protect your home, https://www.portugalwildfires.com/protect-your-home/ (2018).
Ganteaume, A. 64 (INRAE, Product C 2.4. Project Interreg IT-FR MED-Star, 2022).
Parchi Naturali Regionali della Provincia di Lecce. Buone pratiche di prevenzione e autoprotezione dagli incendi boschivi e di vegetazione in interfaccia, https://www.provincia.le.it/pubrepo/repositoryRemoto/2023/INCENDI%20brochure-web.pdf (2023).
Office of the Fire Commission. (ed Province of Manitoba) (2011).
Colorado State Forest Service. The home ignition zone. A guide to preparing your home for wildfire and creating defensible space, https://csfs.colostate.edu/wildfire-mitigation/protect-your-home-property-from-wildfire/ (2021).
Tasmania Fire Service. Prepare your home - create a defendable space, https://www.fire.tas.gov.au/Show?pageId=colPrepare#defendable-space-guide (2022).
Rothermel, R. C. A mathematical model for predicting fire spread in wildland fuels. Vol. 115 (Intermountain Forest & Range Experiment Station, Forest Service, US, 1972).
Morandini, F., Silvani, X., Dupuy, J.-L. & Susset, A. Fire spread across a sloping fuel bed: Flame dynamics and heat transfers. Combust. Flame 190, 158–170 (2018).
Abatzoglou, J. T., Hatchett, B. J., Fox-Hughes, P., Gershunov, A. & Nauslar, N. J. Global climatology of synoptically-forced downslope winds. Int. J. Climatol. 41, 31–50 (2021).
Simpson, C. C., Sharples, J. J., Evans, J. P. & McCabe, M. F. Large eddy simulation of atypical wildland fire spread on leeward slopes. Int. J. Wildland Fire 22, 599–614 (2013).
NSW Rural Fire Service. (ed State of New South Wales) (2019).
Syphard, A. D., Brennan, T. J. & Keeley, J. E. The role of defensible space for residential structure protection during wildfires. Int. J. Wildland Fire 23, 1165–1175 (2014).
Cohen, J. D. Preventing Disaster: Home Ignitability in the Wildland-Urban Interface. J. Forestry 98, 15–21 (2000).
Castillo Soto, M. E., Molina Martínez, J. R., Bonilla, S. & García, R. A. M. Calculating minimum safety distance against wildfires at the wildland-urban interface in Chile and Spain. Heliyon 8, 1–13 (2022).
Frankman, D. et al. Measurements of convective and radiative heating in wildland fires. Int. J. Wildland Fire 22, 157–167 (2013).
Penman, S., Price, O., Penman, T. & Bradstock, R. 1. The role of gardens, nearby houses, water‐sources and topography on the likelihood of house destruction in NSW wildfires from 2001 to 2009. Social Construct of Fuels in the Interface, 7–23 (2014).
Anderson, H. E. Forest fuel ignitibility. Fire Technol. 6, 312–319 (1970).
Popović, Z., Bojović, S., Marković, M. & Cerdà, A. Tree species flammability based on plant traits: A synthesis. Sci. Total Environ. 800, 149625 (2021).
Wyse, S. V. et al. A quantitative assessment of shoot flammability for 60 tree and shrub species supports rankings based on expert opinion. Int. J. Wildland Fire 25, 466–477 (2016).
Etlinger, M. G. & Beall, F. C. Development of a laboratory protocol for fire performance of landscape plants. Int. J. Wildland Fire 13, 479–488 (2004).
Gill, A. M. & Moore, P. H. Ignitibility of leaves of Australian plants. Vol. 34 (CSIRO Canberra, 1996).
Blackhall, M. & Raffaele, E. Flammability of Patagonian invaders and natives: When exotic plant species affect live fine fuel ignitability in wildland-urban interfaces. Landsc. Urban Planning 189, 1–10 (2019).
Murray, B. R. et al. Shoot flammability patterns among plant species of the wildland–urban interface in the fire-prone Greater Blue Mountains World Heritage Area. Int. J. Wildland Fire 32, 1119–1134 (2023).
Ganteaume, A., Jappiot, M., Lampin, C., Guijarro, M. & Hernando, C. Flammability of Some Ornamental Species in Wildland–Urban Interfaces in Southeastern France: Laboratory Assessment at Particle Level. Environ. Manag. 52, 467–480 (2013).
Ocampo-Zuleta, K., Pausas, J. G. & Paula, S. FLAMITS: A global database of plant flammability traits. Glob. Ecol. Biogeogr. 33, 412–425 (2024).
Ganteaume, A., Jappiot, M. & Lampin, C. Assessing the flammability of surface fuels beneath ornamental vegetation in wildland–urban interfaces in Provence (south-eastern France). Int. J. Wildland Fire 22, 333–342 (2013).
El-Beltagi, H. S. et al. Mulching as a sustainable water and soil saving practice in agriculture: A review. Agronomy 12, 1881 (2022).
Chalker-Scott, L. Impact of mulches on landscape plants and the environment — A review. J. Environ. Horticulture 25, 239–249 (2007).
Long, A. et al. in Fire Ecology and Management Congress Proceedings. 13–17 (The Association for Fire Ecology and Washington State University Extension).
Ganteaume, A. et al. Spot fires: fuel bed flammability and capability of firebrands to ignite fuel beds. Int. J. Wildland Fire 18, 951–969 (2009).
Steward, L. G., Sydnor, T. D. & Bishop, B. The ease of ignition of 13 landscape mulches. J. Arboriculture 29, 317–321 (2003).
Beyler, C., Dinaburg, J. & Mealy, C. Development of test methods for assessing the fire hazards of landscaping mulch. Fire Technol. 50, 39–60 (2014).
Manzello, S. L., Cleary, T. G., Shields, J. R. & Yang, J. C. Ignition of mulch and grasses by firebrands in wildlandurban interface fires. Int. J. Wildland Fire 15, 427–431 (2006).
Suzuki, S., Manzello, S. L., Kagiya, K., Suzuki, J. & Hayashi, Y. Ignition of mulch beds exposed to continuous wind-driven firebrand showers. Fire Technol. 51, 905–922 (2015).
Johnsson, E. in Encyclopedia of wildfires and wildland-urban interface (WUI) fires (Springer, 2020).
Leonard, J. et al. Research and investigation into the performance of residential boundary fencing systems in bushfires. (2006).
Valette, J., Gomendy, V., Marechal, J., Houssard, C. & Gillon, D. Heat-transfer in the soil during very low-intensity experimental fires - the role of duff and soil-moisture content. Int. J. Wildland Fire 4, 225–237 (1994).
Nolan, R. H. et al. Linking forest flammability and plant vulnerability to drought. Forests 11, 779 (2020).
Potter, M. & Leonard, J. E. Spray system design for ember attack - research findings and discussion paper. (Bushfire and Natural Hazards CRC, East Melbourne, Australia, 2010).
Johnson, J. F., Downing, T. & Nelson, K. C. External sprinkler systems and defensible space: lessons learned from the Ham Lake fire and the Gunflint Trail. (University of Minnesota, College of Food, Agricultural and Natural Resource, 2008).
Green, A. & Kaye, N. B. On the use of sprays to intercept airborne embers during wildfires. Fire Safety J. 108, 102842 (2019).
Penman, T. D., Eriksen, C. E., Horsey, B. & Bradstock, R. A. How much does it cost residents to prepare their property for wildfire? Int. J. Disaster Risk Reduc. 16, 88–98 (2016).
Blanchi, R. et al. Best practice design for building in bushfire prone areas in Victoria. v1. (CSIRO. Service Collection, 2021).
Australian Institute of Architects. Site planning and design for bushfire. (2021).
Gibbons, P. et al. Options for reducing house-losses during wildfires without clearing trees and shrubs. Landsc. Urban Planning 174, 10–17 (2018).
MacLeod, T. A., Hahs, A. K. & Penman, T. D. Balancing fire risk and human thermal comfort in fire-prone urban landscapes. PLOS ONE 14, e0225981 (2019).
Syphard, A. D. & Keeley, J. E. Factors associated with structure loss in the 2013–2018 California wildfires. Fire 2, 49 (2019).
Wotton, B. M., Gould, J. S., McCaw, W. L., Cheney, N. P. & Taylor, S. W. Flame temperature and residence time of fires in dry eucalypt forest. Int. J. Wildland Fire 21, 270–281 (2012).
Gormley, A. G., Bell, T. L. & Possell, M. Non-additive effects of forest litter on flammability. Fire 3, 12 (2020).
Lachlan McCaw, W., Gould, J. S., Phillip Cheney, N., Ellis, P. F. M. & Anderson, W. R. Changes in behaviour of fire in dry eucalypt forest as fuel increases with age. Forest Ecol. Manag. 271, 170–181 (2012).
Penman, T. D. et al. Retrofitting for wildfire resilience: What is the cost? Int. J. Disaster Risk Reduc. 21, 1–10 (2017).
Syphard, A. D., Rustigian-Romsos, H. & Keeley, J. E. Multiple-scale relationships between vegetation, the wildland–urban interface, and structure loss to wildfire in California. Fire 4, 12 (2021).
Platt, R. V. Wildfire hazard in the home ignition zone: An object-oriented analysis integrating LiDAR and VHR satellite imagery. Appl. Geogr. 51, 108–117 (2014).
Schmidt, J. The Butte fire: A case study in using LIDAR measures of pre-fire vegetation to estimate structure loss rates. Munich Personal RePEc Archive, 1–23 (2020).
Goddard, M. A., Dougill, A. J. & Benton, T. G. Scaling up from gardens: biodiversity conservation in urban environments. Trends Ecol. Evol. 25, 90–98 (2010).
Pryke, J. S., Samways, M. J. & Hockey, P. A. R. Persistence of the threatened Knysna warbler Bradypterus sylvaticus in an urban landscape: do gardens substitute for fire? African J. Ecol. 49, 199–208 (2011).
Lubbe, C. S., Siebert, S. J. & Cilliers, S. S. Floristic analysis of domestic gardens in the Tlokwe City Municipality, South Africa. Bothalia 41, 351–361 (2011).
van Helden, B. E., Close, P. G., Stewart, B. A., Speldewinde, P. C. & Comer, S. J. Critically Endangered marsupial calls residential gardens home. Animal Conserv. 24, 445–456 (2021).
Akinnifesi, F. K. et al. Biodiversity of the urban homegardens of São Luís city, Northeastern Brazil. Urban Ecosyst.13, 129–146 (2010).
Loram, A., Thompson, K., Warren, P. H. & Gaston, K. J. Urban domestic gardens (XII): The richness and composition of the flora in five UK cities. J. Veg. Sci. 19, 321–330 (2008).
Thompson, K. et al. Urban domestic gardens (I): Putting small-scale plant diversity in context. J. Veg. Sci. 14, 71–78 (2003).
Gbedomon, R. C., Salako, V. K., Adomou, A. C., Glèlè Kakaï, R. & Assogbadjo, A. E. Plants in traditional home gardens: richness, composition, conservation and implications for native biodiversity in Benin. Biodivers. Conserv. 26, 3307–3327 (2017).
Delahay, R. J., Sherman, D., Soyalan, B. & Gaston, K. J. Biodiversity in residential gardens: a review of the evidence base. Biodivers. Conserv. 32, 4155–4179 (2023).
Murray, B. R., Martin, L. J., Brown, C., Krix, D. W. & Phillips, M. L. Selecting low-flammability plants as green firebreaks within sustainable urban garden design. Fire 1, 15 (2018).
Zhao, Y., van den Berg, P. E. W., Ossokina, I. V. & Arentze, T. A. How do urban parks, neighborhood open spaces, and private gardens relate to individuals’ subjective well-being: Results of a structural equation model. Sustain. Cities Soc. 101, 105094 (2024).
Goddard, M. A., Dougill, A. J. & Benton, T. G. Why garden for wildlife? Social and ecological drivers, motivations and barriers for biodiversity management in residential landscapes. Ecol. Econ. 86, 258–273 (2013).
Kurz, T. & Baudains, C. Biodiversity in the Front Yard:An Investigation of Landscape Preference in a Domestic Urban Context. Environ. Behav. 44, 166–196 (2012).
Bowman, D. M. J. S. & McCormack, P. C. Arrested policy development of private fire shelters (fire bunkers) is a barrier to adaptation to the Australian bushfire crisis. Fire 6, 298 (2023).
Portuguese Government. Decree-Law n°10/2018, https://files.diariodarepublica.pt/1s/2018/02/03200/0096700968.pdf (2018).
Greek Government. Regulation for Fire Protection of Properties within or in Proximity to Forest Areas. Greek Government Gazette: Athens, Greece. Ministerial Decision 3475/2023, https://www.et.gr/api/DownloadFeksApi/?fek_pdf=20230203475 (2023).
French Republic. Code Forestier francais, https://www.legifrance.gouv.fr/codes/texte_lc/LEGITEXT000025244092 (2012).
State of California. Public resources code. Section 4291, 2022).
Northern Territory Government. (Northern Territory of Australia, 2016).
Casartelli, V. & Mysiak, J. Wildfire peer-review assessment framework. (2023).
Brenkert-Smith, H., Champ, P. A. & Flores, N. Trying not to get burned: Understanding homeowners’ wildfire risk–mitigation behaviors. Environ. Manag. 50, 1139–1151 (2012).
Lucas, C. H., Williamson, G. J. & Bowman, D. M. J. S. Neighbourhood bushfire hazard, community risk perception and preparedness in peri-urban Hobart, Australia. Int. J. Wildland Fire 31, 1129–1143 (2022).
Ergibi, M. & Hesseln, H. Awareness and adoption of FireSmart Canada: Barriers and incentives. Forest Policy Econ. 119, 102271 (2020).
Acknowledgements
This work was funded by Australian Research Council Laureate Fellowship FL220100099 awarded to DMJSB and Natural Hazards Research Australia project T2-A5: Bushfire risk at the rural-urban interface. The funders played no role in study design, data collection, analysis and interpretation of data, or the writing of this manuscript.
Author information
Authors and Affiliations
Contributions
S.O., O.F.P. and D.M.J.S.B. contributed to study conception and design. S.O. searched and summarised the guidelines. S.O. and D.M.J.S.B. led the writing. O.F.P. reviewed and edited the manuscript. All authors read and approved the final manuscript.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
Ondei, S., Price, O.F. & Bowman, D.M. Garden design can reduce wildfire risk and drive more sustainable co-existence with wildfire. npj Nat. Hazards 1, 18 (2024). https://doi.org/10.1038/s44304-024-00012-z
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s44304-024-00012-z
