Measurements of seasonal patterns of live fuel moisture content and ignitability (in terms of time to ignition) of four Mediterranean shrub species were performed in North Western Sardinia (Italy). Relationships between the two variables were evaluated. Relationships between live fuel moisture content and environmental conditions (i.e. rainfall, air temperature and soil moisture) were analysed. Two groups of species were identified in relation to the different response of live fuel moisture content to seasonal meteorological conditions. Seasonal patterns of live fuel moisture content were also compared with five meteorological drought indices: Duff Moisture Code and Drought Code of the Canadian Forest Fire Weather Index System, Keetch–Byram Drought Index, Canopy Drought Stress Index and Cumulative Water Balance Index. In addition, the capability of the meteorological drought indices to describe moisture variation for each species was evaluated. Although the Drought Code was formulated to describe changes in the moisture content of dead fuel, it was shown to have a good potential for modelling live fuel moisture variation of a group of shrubland species that are sensitive to meteorological conditions, with a clear and large decrease of moisture content during the drought season.

The objectives of the present study were (i) to describe the seasonal pattern of ignition delay (ID time) and moisture content of live fine fuel (LFMC) for eight common shrub species of the Western Mediterranean Basin, and (ii) to evaluate the relationships between LFMC and ignitability. The experiment was carried out in a shrubland area located in Sardinia, Italy. LFMC and time to ignition or ID time values were determined monthly or twice a month throughout the year. Ignitability was determined by laboratory tests. Meteorological data were also collected from a weather station located in the study area. Significant linear regression equations of ID time v. LFMC were found for most of the species, with R2 values ranging from 67 to 94%. In general, very low values of ID time were observed when LFMC ranged from 70 to 100%. In addition, two groups of species were identified, depending on seasonal changes of both LFMC and ID time (or ignitability): (i) species with LFMC not greater than 100% and high ignitability values all throughout the year, and (ii) species with large seasonal variability of LFMC and ignitability values that were low in winter and high in summer. Significant differences in ignitability among species were also observed.

In Mediterranean agropastoral areas, land abandonment is a key driver of wildfire risk as fuel load and continuity increase. To gain insights into the potential impacts of land abandonment on wildfire risk in fire-prone areas, a fire-spread modeling approach to evaluate the variations in wildfire potential induced by different spatial patterns and percentages of land abandonment was applied. The study was carried out in a 1200 km² agropastoral area located in north-western Sardinia (Italy) mostly covered by herbaceous fuels. We compared nine land abandonment scenarios, which consisted of the control conditions (NA) and eight scenarios obtained by combining four intensity levels (10, 20, 30, 40%) and two spatial patterns of agropastoral land abandonment. The abandonment scenarios hypothesized a variation in dead fuel load and fuel depth within abandoned polygons with respect to the control conditions. For each abandonment scenario, wildfire hazard and likelihood at the landscape scale was assessed by simulating over 17,000 wildfire seasons using the minimum travel time (MTT) fire spread algorithm. Wildfire simulations replicated the weather conditions associated with the largest fires observed in the study area and were run at 40 m resolution, consistent with the input files. Our results highlighted that growing amounts of land abandonment substantially increased burn probability, high flame length probability and fire size at the landscape level. Considering a given percentage of abandonment, the two spatial patterns of abandonment generated spatial variations in wildfire hazard and likelihood, but at the landscape scale the average values were not significantly different. The average annual area burned increased from about 2400 ha of the control conditions to about 3100 ha with 40% land abandonment. The findings of this work demonstrate that a progressive abandonment of agropastoral lands can lead to severe modifications in potential wildfire spread and behavior in Mediterranean areas, thus promoting the likelihood of large and fast-spreading events. Wildfire spread modeling approaches allow us to estimate the potential risks posed by future wildfires to rural communities, ecosystems and anthropic values in the context of land abandonment, and to adopt and optimize smart prevention and planning strategies to mitigate these threats.

Wildfires represent a major threat to Mediterranean ecosystems and are responsible for relevant impacts to environmental, economic and social values. In the period 2010-2016, the cross-border Interreg Italy-France Maritime territory, which includes Sardinia, Corsica, Tuscany, Liguria and PACA Regions, had about 20,000 wildfire ignitions and a total burned area of about 122,000 ha. In the face of social and environmental conditions and risks of the Maritime Regions, strengthening and developing innovative common guidelines and systems of wildfire management, from the monitoring and forecast to suppression, can provide more effective solutions to the wildfire problem, and can help strengthen cross-border cooperation in case of days with high risk. This work is devoted to introduce the MED-Star project, and to describe his main activities and results, with a focus on the tasks and activities coordinated by the National Research Council of Italy, Institute of BioEconomy (CNR-IBE) of Sassari. MED-Star is a 3-years strategic project supported by the Interreg Italy-France Maritime Program 2014-2020, which is co-financed by the European Regional Development Fund (ERDF). MED-Star is closely linked to 4 joint simple projects (Intermed; Med-Coopfire; Med-Foreste; Med-PSS), which mainly focus on investments in small infrastructures for wildfire risk prevention and support to wildfire suppression operations. The MED-Star project aims to share and discuss fire management policies and the most advanced strategies that can reduce the risk associated with wildfires, also through the combination of joint action plans and pilot / demonstration actions. The partnerships of MED-Star and the related 4 simple projects include the main actors competent at the administrative, technical and scientific level on the wildfire topic in the Maritime area of cooperation, and are able to meet the abovementioned challenges, contributing to 1) the reduction of wildfire risk in the five Regions involved, 2) the definition of strategic and operational solutions, 3) the implementation of operational actions and investments for wildfire prevention, monitoring, forecast and suppression, and 4) the strengthening of joint early warning and risk monitoring systems.

In this work, we will present the transboundary wildfire simulation system used to analyze fine-scale (100-m resolution) wildfire hazard and exposure in the regions of the Italy–France Maritime cooperation area (Sardinia, Corsica, Tuscany, Liguria and Provence–Alpes–Côte d’Azur), which covers about 93,000 km² of land. The study area is characterized by a variety of ecological, cultural, anthropic and touristic values that are heavily threatened by wildfires, mostly during the summer season. The wildfire issues in the area are expected to worsen in future years due to a number of contributing factors, including climate change, the abandonment of agrosilvopastoral areas with the resulting increase in fuel load and continuity and the expansion of urban interfaces into fire-prone wildlands. To perform our analysis, among the large set of wildfire spread models available, in the framework of the MED-Star project, we have selected the Minimum Travel Time (MTT) algorithm of Finney (2002) as implemented in FConstMTT. As inputs for our simulations, we produced underlying fuel maps derived from regional land use and forest maps and focused on the historical moisture and weather conditions and patterns associated with the largest wildfires that affected the study area in the last 20 years. The simulation outputs allowed us to characterize spatial variations in wildfire spread and hazard among and within provinces and regions and to identify the most significant hot-spot areas. In addition, we combined the simulated raster data with several explanatory variables and spatial layers (e.g., wildland–anthropic interface maps; provinces; climatic zones; etc.) to characterize exposure levels at different levels. Findings from this work improve regional awareness and knowledge about the spatial dynamics and patterns of wildfire exposure and hazard in the Italy–France Maritime cooperation area.