Mario Elia

Developing custom fire behavior fuel models for Mediterranean wildland–urban interfaces in southern Italy

The dramatic increase of fire hazard in wildland–urban interfaces (WUIs) has required more detailed fuel management programs to preserve ecosystem functions and human settlements. Designing effective fuel treatment strategies allows to achieve goals such as resilient landscapes, fire-adapted communities, and ecosystem response. Therefore, obtaining background information on forest fuel parameters and fuel accumulation patterns has become an important first step in planning fuel management interventions. Site-specific fuel inventory data enhance the accuracy of fuel management planning and help forest managers in fuel management decision-making. We have customized four fuel models for WUIs in southern Italy, starting from forest classes of land-cover use and adopting a hierarchical clustering approach. Furthermore, we provide a prediction of the potential fire behavior of our customized fuel models using FlamMap 5 under different weather conditions. The results suggest that fuel model IIIP (Mediterranean maquis) has the most severe fire potential for the 95th percentile weather conditions and the least severe potential fire behavior for the 85th percentile weather conditions. This study shows that it is possible to create customized fuel models directly from fuel inventory data. This achievement has broad implications for land managers, particularly forest managers of the Mediterranean landscape, an ecosystem that is susceptible not only to wildfires but also to the increasing human population and man-made infrastructures.

Cumulative effects of wildfires on forest dynamics in the eastern Cascade Mountains, USA

Wildfires pose a unique challenge to conservation in fire-prone regions, yet few studies quantify the cumulative effects of wildfires on forest dynamics (i.e., changes in structural conditions) across landscape and regional scales. We assessed the contribution of wildfire to forest dynamics in the eastern Cascade Mountains, USA from 1985 to 2010 using imputed maps of forest structure (i.e., tree size and canopy cover) and remotely sensed burn severity maps. We addressed three questions: (1) How do dynamics differ between the region as a whole and the unburned portion of the region? (2) How do dynamics vary among vegetation zones differing in biophysical setting and historical fire frequency? (3) How have forest structural conditions changed in a network of late successional reserves (LSRs)? Wildfires affected 10% of forests in the region, but the cumulative effects at this scale were primarily slight losses of closed-canopy conditions and slight gains in open-canopy conditions. In the unburned portion of the region (the remaining 90%), closed-canopy conditions primarily increased despite other concurrent disturbances (e.g., harvest, insects). Although the effects of fire were largely dampened at the regional scale, landscape scale dynamics were far more variable. The warm ponderosa pine and cool mixed conifer zones experienced less fire than the region as a whole despite experiencing the most frequent fire historically. Open-canopy conditions increased slightly in the mixed conifer zone, but declined across the ponderosa pine zone even with wildfires. Wildfires burned 30% of the cold subalpine zone, which experienced the greatest increase in open-canopy conditions and losses of closed-canopy conditions. LSRs were more prone to wildfire than the region as a whole, and experienced slight declines in late seral conditions. Despite losses of late seral conditions, wildfires contributed to some conservation objectives by creating open habitats (e.g., sparse early seral and woodland conditions) that otherwise generally decreased in unburned landscapes despite management efforts to increase landscape diversity. This study demonstrates the potential for wildfires to contribute to regional scale conservation objectives, but implications for management and biodiversity at landscape scales vary geographically among biophysical settings, and are contingent upon historical dynamics and individual species habitat preferences.

Modeling fire ignition patterns in Mediterranean urban interfaces

The rapid growth of built-up areas and infrastructure in the Mediterranean environment has resulted in the expansion of urban interfaces where fire can ignite and spread. Within this context, there is a need to understand spatial patterns of ignition distribution and the relative importance of influencing drivers. In response to this need we developed an analysis of fire ignition patterns using human and biophysical explanatory variables by firstly developing two different linear models to assess patterns of fire ignition points in terms of occurrence (presence/absence) and frequency (number of ignition points per area and secondly applying statistical tests to both models to evaluate the most important human and/or biophysical drivers influencing these patterns. The probability of ignition point occurrence and frequency were mapped using the predicted values of the two models in the Apulia region (southern Italy). Our findings revealed that dependent variables (fire ignition occurrence points and frequency) are negatively correlated with population density, but positively correlated for presence of urban areas with a significantly higher likelihood of ignition in cultivated (crop)land, forest, shrubland, grassland, and other natural spaces. The probability of ignition increased with elevation and slope. The maps show that the probability of ignition occurrence is relevant along the coast in the northern and southern parts of the region, especially in urban interfaces with a strong presence of shrubland and Mediterranean maquis. Ignition point frequency was predicted along the coast, particularly in the south and in some densely urbanized inland areas. By adopting the models, forest managers and decision makers may avail of the knowledge gained to design and promote sustainable fire management strategies in the Apulia region.