Due to the associated fire risk, the wildland–urban interface (WUI) has drawn the attention of researchers and managers from a range of backgrounds. From a land management point of view, it is important to identify the WUI to determine areas to prioritise for fire risk prevention. It is also important to know the fire risk mitigation measures available to select the most appropriate for each specific context. In this systematic review, definitions of the WUI were investigated and physical mitigation measures for reducing the risk of fire were examined from a land management perspective. The PRISMA 2020 Statement was applied to records published until 31 December 2022 and retrieved from the Web of Science, Scopus, and other research engines. A total of 162 publications from scientific journals and the grey literature were scrutinised and selected for analysis. Only publications providing an original definition of the WUI or proposing physical measures to reduce fire risk at the interface were retained, while those relating to emergency management and social perception were not considered. The risk of bias was reduced by internal cross-assessment by the research team. Definitions of the WUI (n = 40 publications) changed according to the research objective, varying broadly in identification of the anthropogenic and the wildland components of the interface. Terminology varied according to the definition, and the term wildland–human interface (WHI) was found to be more comprehensive than WUI. Methodological definitions of the interface ranged from using aggregated data through to identification of the buildings at risk in the interface with considerable precision. Five categories of physical fire risk mitigation measures (n = 128 publications) were identified: clearance distances, landscaping, wildland fuel management, land planning, and buildings design and materials. The most effective measures were those applied at early stages of urban development, and maintenance of assets and vegetation is crucial for preparedness. This review represents an analysis of scientific evidence on which land managers can base their actions to reduce the fire hazard risk in the WUI. The number of studies investigating the WUI is considerable, but experimental studies and quantitative results are scarce, and better communication and coordination among research groups and land management agencies is advisable. This systematic review was not registered.

After large and severe wildfires, the establishment of tree regeneration, particularly for species without specific fire-adaptive traits, can be challenging. Within harsh environments, the presence of favorable microsites, as those provided by deadwood, enhancing microclimatic conditions, is crucial to the re-establishment of forest cover and thus to foster recovery dynamics. Active restoration strategies can have an impact on these dynamics, altering or hindering them. The main hypothesis of this study is that manipulating deadwood in terms of quantity and spatial arrangement can result in differences in natural regeneration density and composition. Post-disturbance regeneration dynamics and the role played by deadwood over time in the creation of safe sites for seedling establishment were investigated in an area affected by a high-severity wildfire that underwent different post-fire restoration treatments along a gradient of increasing deadwood manipulation, spanning from salvage logging to non-intervention. Two inventories were performed 5 and 11 years after the fire. Ground cover proportion was significantly different among treatments, with lower values of lying deadwood in salvaged sites. A higher probability of regeneration establishment close to deadwood was found in both surveys, confirming the facilitating role of deadwood on post-fire forest regeneration. Microsite dynamics resulting from deadwood facilitation were highlighted, with establishment probability and anisotropic relationships between deadwood elements and seedlings changing over time, as recovery processes slowly improved environmental conditions. In dry mountain areas affected by stand-replacing wildfires, by removing deadwood, salvage logging reduces the number of safe sites for regeneration, further impairing the ecosystem recovery. Passive management should be the ecologically preferred management strategy in these conditions, although intermediate interventions (e.g., felling without delimbing, leaving deadwood on the ground) could be effective alternatives, accelerating snag fall dynamics and immediately increasing favorable microsite availability.

Wildland fires and windthrows represent relevant disturbances for forest ecosystems worldwide. In this context, especially for Italian catchments, the interaction between windthrows and changes in wildfire behaviour starting from ALS data processing is scarcely investigated. Therefore, this research aims to compute a multi-temporal analysis of the interaction between windthrows and wildfire behaviour in a forested area (Veneto region, northern Italy), recently affected by the renamed Vaia windstorm. The semi-empirical FlamMap model was applied, starting from ALS data processing implemented in R for mapping the spatial distribution of forest attributes and fuels within the catchment. The role of windthrows in altering wildfire behaviour was investigated considering ALS point clouds acquired before and after the occurrence of the storm Vaia. Digital Terrain Models (DTMs), Canopy Height Models (CHMs), topographic data and metrics describing forest structure were extracted from ALS data for both scenarios at 5 m resolution, to compare changes in wildfire behaviour over time. Differences in Rate of Spread (RoS), flame length (FL), midflame windspeed (WS) and arrival time (AT) were assessed, and their correlation with windstorm damages was investigated at the catchment detail. , An increase of RoS, FL, and WS greater than 30 m/min, 3 m and 1.1 m/s were respectively estimated in windthrown areas, as well as a decrease of AT greater than 30 min, attesting the key role of windthrows in altering wildfire behaviour over time. The correlation between windthrows and changes in wildfire attributes was finally modeled by computing regression analysis, with R² of 0.86, 0.93, 0.62, and 0.91 resulted for RoS, FL, WS and AT. This research represents a pilot case study for better detecting changes in wildfires behaviour due to windthrows occurrence, therefore proposing and carrying out effective planning and management strategies for disturbed forest stands over time.

Background: Forest recovery from natural disturbances is often linked to the biological legacies left in the aftermath. In the case of forest fires, coarse woody debris, and specifically downed logs, is recognized as preferential sites for forest regeneration, for the improved environmental conditions around them. In this study, we monitored the effect of barriers made of downed logs on near-surface (5 cm depth) soil temperature and soil moisture during the summer of 2022 (9 dates) in a conifer forest in Central Italy burnt in 2017. We took measurements at various distances from the barriers to assess the spatial extent of their influence on soil moisture and temperature. Leveraging the presence of log erosion barriers in the field, we compared the effects of naturally fallen (n = 14) and artificially placed (n = 19) logs. Results: We recorded lowest soil temperature and soil moisture in the immediate proximity of the logs, with values not significantly different from control points at a distance of one time the height of the barriers. This pattern was consistent throughout the summer, regardless of the type of barrier (natural/artificial). The decrease in soil temperature is probably caused by the interception of solar radiation, while the decrease in soil moisture is counterintuitive, and would require further investigation. The type of barrier did not influence soil temperature, but we recorded lower moisture around artificial barriers, suggesting that their positioning may have altered soil moisture retention capacity. Conclusions: From a management perspective, logs may be considered preferential sites for natural or artificial regeneration. Nonetheless their effect on near-surface soil moisture and temperature fades within a short distance, and their influence may be either positive or negative for natural regeneration, depending on the local limiting factors.

Fuel management is a crucial action to maintain wildland fires under the threshold of manageability; hence, in order to allocate resources in the best way, wildland fuel mapping is regarded as a necessary tool by land managers. Several studies have used Aerial Laser Scanner (ALS) data to estimate forest fuels characteristics at plot level, but few have extended such estimates at a zonal level.In the context of the EU Interreg Project CROSSIT SAFER, a test of the possibilities of ALS data to predict fuels attributes has been performed in three different areas: an alpine basin, a coastal wildland-urban interface and a karstic highland. Eighteen sampling plots have been laid out over 6 forest categories, with a special focus on Pinus nigra J. F. Arnold artificial forests. Low density (average 4 points/m2) discrete return LiDAR data has been analysed with FUSION, a free point cloud analysis software tailored to forestry purposes; field and remote sensing data have been connected with simple statistical modelling and results have been spatialised over the case study areas to provide wall-to-wall inputs for FLAMMAP fire behaviour simulation software.Resulting maps can be of relevance for land managers to better highlight the most vulnerable or fire prone areas at a mesoscale administrative level. Limitations and room for improvement are pointed out, in the view that land management should keep updated with the latest technology available.

In a conifer forest in Central Italy burnt by wildfire in 2017, shallow sub-surface (topmost 5 cm) soil temperature and soil moisture (% volumetric water content) were measured during summer 2022. Various distances from downed trees (natural barriers) and log erosion barriers (artificial barriers) were sampled. Additional data on the hour of sampling, barriers characteristics, and barriers location were collected.