Roadside Vegetation Planning and Conservation: New Approach to Prevent and Mitigate Wildfires Based on Fire Ignition Potential

Wildfires in urban landscapes spreading into forested landscapes are a growing problem due to socioeconomic and climate changes. Fire ignition and flame spread depend on meteorological and environmental conditions and the physicochemical traits of the fuel. In this approach, environmental variables and geostatistical techniques (maximum entropy model) identify distance to roads (37.9% of importance) and distance to settlements (18.4% of importance) as the most meaningful variables explaining fire ignition potential at a regional scale. Hence, the assessment of the ignition potential of roadside vegetation may play a cornerstone role in fire prevention management. In this research, our aim was to identify the fire ignition potential on roadsides according to fire ignition likelihood and the flammability of the main species at particle level. The flammability of 14 species found on Spanish roadsides was studied at the bench-scale using flammability categories classification, combustion index and flammability index. Nerium oleander, Tamarix gallica and Washingtonia filifera limited the potential to fire spread based on ability to start a fire. Chamaerops humilis, Pistacia lentiscus, Olea europaea var. sylvestris, Retama shaerocarpha and Spartium junceum would be useful due to their less severe fire spreading in order to improve the landscape and biodiversity components of the road projects. Due to the global importance of human risk (road presence) in fire occurrence, this approach should be a suitable tool for planning the construction and maintenance of roads, from the perspective of fire prevention and fire impacts mitigation.