Landscape vulnerability to wildfires at the forest-agriculture interface: half-century patterns in Spain assessed through the SISPARES monitoring framework

Large-scale socioeconomic changes in recent decades have driven shifts in the structure of Spanish rural landscapes, particularly in those located at the forest-agriculture interface (FAI), as well as in their wildfire regime. Using data from more than 200 16 km(2) landscape plots in Spain surveyed between 1956 and 2008 through the SISPARES monitoring framework, we assessed the FAI vulnerability to wildfires and identified the main landscape structural factors related to an increased number of wildfire events. We found that the most vulnerable landscapes were those with high road density, high diversity of land uses and, most importantly, with fine-grained forest-agriculture mixtures. Ignition frequency was lower in those landscapes where crops and woodlands coexisted but distributed in large and well-separated patches, and much lower where both land uses were combined within an integrated production and management system (dehesas). We discuss the geographical distribution patterns and temporal trends of the different FAI types during recent decades. We conclude that such approach is useful to forecast the mutual interactions between land use pattern changes and wildfire regime in the Mediterranean agroforestry mosaics. This would also provide an ecological base for developing a complementary, cost-effective and durable passive strategy of wildfire management targeted to modify the inherent FAI susceptibility to ignition events.