Wildfire connectivity under drought-induced impacts and landscape management strategies in a Mediterranean region

Global warming and land-use changes have increased wildfire risk in Mediterranean regions. Landscape management strategies (LMS) potentially can reduce extreme wildfire behavior through the maintenance and recovery of traditional agroforestry mosaics. However, we still have limited knowledge about LMS viability regarding their interaction with the ongoing escalation of drought-induced forest mortality. Here, we assess how drought impacts interact with LMS to shape wildfire connectivity in the Barcelona Metropolitan Region (NE, Spain). We simulated forest dynamics and fire connectivity from 2015 to 2050 under a Business-as-usual LMS by applying process-based modeling and considering two climatic scenarios differing in drought intensity levels. Then, we analyzed differences in wildfire connectivity patterns arising from the interaction between drought events and three alternative LMS co-designed with local stakeholders: recovering former croplands, increasing wood harvesting and logging drought-affected stands. According to our simulations, forest dynamics and drought-induced impacts modified stand structures and fine fuel loads, ultimately reducing fire connectivity by 2040-2050. A larger average fire connectivity reduction occurred under a higher incidence of extreme-drought events, although this scenario was also associated with annual peaks of extreme fire connectivity events. Crop-recovery decreased fire connectivity regardless of the drought intensity, while Harvesting-increase resulted in fire connectivity patterns similar to Business-as-usual under both climatic scenarios. Drought-stands-logging resulted in the greatest and most spatially uniform reduction in fire connectivity when simulated under high-drought intensity, due to the elimination of annual peaks following drought episodes. According to our results, there is room for combining drought-induced impacts with LMS to reduce wildfire connectivity at regional scales in fire-prone Mediterranean areas.