In the last decades, in the Valencia region (eastern Spain), as in most northern Mediterranean countries, land abandonment caused profound changes in the structure and functioning of landscapes. The increase of fuel accumulation over large areas led to an increasing number of fires since the mid-1970s. This trend might be enhanced in the medium term by climatic change. Fires have become a major degradation factor in Mediterranean landscapes (decreasing soil fertility, soil loss, loss of biodiversity, etc.). Fire prevention and post-fire restoration are, thereby, two major objectives for forest managers. A spatial tool based on scientific knowledge aiming to support a sustainable planning of multi-objective (development, conservation, restoration) forest management in Mediterranean landscapes has not been successfully validated yet. The main objectives of this study were: 1) to parameterize for Mediterranean conditions the spatial decision support system (SDSS) ForestERA (http://www.forestera.nau.edu/), which was developed for supporting forest restoration in the Southwestern U.S., 2) to develop a procedure based on the use of this SDSS for fuel treatment optimization in the study area (Ayora, Valencia), and 3) to test the effectiveness of different fuel scenarios for controlling fire propagation and moderating fire behavior, taking also into account the conservation of soil and water and the promotion of the resilience of ecosystems and landscape to fire.
Results/Conclusions
In a first stage, we studied the set of models (vegetation, fire, watersheds) that comprise the SDSS and the relationships between the system components throughout the spatial decision procedure. We created the spatial database required for running the models that are related to the achievement of our objectives. We developed a method for identifying the optimal placement of fuel treatments in the landscape in relation to our management objectives combining models that are integrated in ForestERA and new ones, such as FARSITE that we previously parameterized for our area and a recently-developed model of ecological vulnerability to fire. The ArcGIS-based analysis procedure allowed to prioritize areas of high value and high risk and design alternative fuel scenarios, which are being tested through an iterative simulation process to permit direct comparison of their relative effects on fire growth and behavior. We considered the worse-case weather scenario, previously characterized for our site. Preliminary results suggest that the spatial arrangement of treatment units strongly determines fire propagation and behavior and that the SDSS could be an effective tool for supporting the landscape-level design of sustainable management strategies in Mediterranean forests.