Will fire-smart landscape management buffer the effects of climate and land-use changes on fire regimes?

Abstract

Long-term farmland abandonment has increased fuel build-up in many Euro-Mediterranean mountainous regions. The high fuel hazard in these landscapes, combined with ongoing climate change, is increasing the frequency of extreme wildfires, thus altering contemporary fire regimes. Mitigating the loss of the landscape’s capacity to regulate large and intense fires is crucial to prevent future harmful effects of fires. As such, effective strategies to manage these fire-prone landscapes are needed. Yet, further understanding of their performance under global change scenarios is required. This study assessed the effects of fire-smart management strategies on future landscape dynamics, fire regulation capacity (FRC), and fire regime in a Mediterranean fire-prone mountainous landscape in Portugal (30,650 ha) undergoing long-term land abandonment and climate change scenarios. For that, we applied the LANDIS-II model under climate change scenarios (RCP 4.5 and 8.5) and long-term farmland abandonment (2020–2050) according to three fire-smart management strategies focused on fire prevention compared with a business-as-usual (BAU) strategy based on fire suppression. Future fire activity and land dynamics resulted in changes that fostered landscape heterogeneity and fragmentation and favoured fire-adapted forests and agroforestry systems while decreasing the dominance of shrublands and croplands. FRC decreased over time, particularly under RCP 8.5 and the BAU strategy. In turn, fire-smart strategies better prevented large and intense fires than the BAU strategy, but their effectiveness decreased under RCP 8.5. The loss of FRC resulted in increased burned area and fire frequency, which predicts a shift from contemporary fire regimes but more markedly under RCP 8.5 and in the BAU strategy. Fire-smart strategies outperformed BAU in averting current fire regime intensification. Merging forest- and silvopasture-based management is the most promising approach in taming the effects of climate and farmland abandonment on future fire activity. Our study underlines that planning and management policies in fire-prone Mediterranean mountain landscapes must integrate fire-smart strategies to decrease landscape fuel hazard and buffer the impact of global change on future fire regimes.