Temperature and agriculture are largely associated with fire activity in Central Chile across different temporal periods

Wildfires have important ecological and socio-economic implications worldwide. Identifying the major ecological drivers regulating fire activity across space and time is critical to formulating sustainable policies of landscape planning and management under global change scenarios. However, large scale studies quantifying the relative importance of relevant fire drivers across different time periods are largely lacking. We conducted a high-resolution spatial survey in Central Chile and used structural equation models (SEMs) to evaluate the direct and indirect effects of climate, human impact, land uses, and topography on the number of fires and burned area across two distinct periods of time (2000-2005 and 2011-2016). Mean temperature and agricultural use had the highest direct positive effect on the number of fires and burned area in the two studied periods, and thus were the major ecological predictors of fire activity. Human impact was also an important predictor of fire attributes. Topography had multiple indirect effects on fire activity by regulating land use, temperature, and human impact, but direct effects were negligible. Precipitation seasonality, drought and aridity indexes, native forests, and plantations, were less relevant predictors of fire activity. Even so, our SEMs suggested that areas dominated by native forests tended to have lower number of fires than those covered by croplands or plantations. Our results suggest that fire activity in Central Chile will be highly sensitive to increases in human pressure, land use change and warming by climate change. Because the relative importance of the predictors of fire activity was steady over time, the knowledge derived from this study provides critical insights for preventive fire management and landscape planning. The control of stubble burning, native forest restoration and sustainable forestry management could improve social adaptation to a fire-prone future.