Fire patterns in central semiarid Argentina

Abstract

Wildfires can cause severe impacts on the terrestrial ecosystems depending on their frequency and behavior. We studied the environmental factors influencing the spatial and temporal distribution of fires, their size and duration in the central semiarid Argentina. We identified fires using MODIS satellite data and we analyzed their association with climate and land cover/use patterns. Spatial and temporal fire patterns varied between eastern, central and western regions according to the presence of agriculture, shrublands and water deficits, respectively. The frequency and behavior of fires also varied temporally with water conditions. Years with low effective precipitations were characterized by an important hotspot density and fire number, as well as the months preceded by two months with low effective precipitation (r 2: 0.42; p < 0.0001). We observed a spatial delay of fires in a northeast-southwest sense, related to the delay of the spring beginning (r 2: 0.7594; p < 0.0001). The mean fire sizes and duration varied significantly among vegetation types (F: 10.76, p < 0.0001 and F: 3.703, p < 0.01). Fires were bigger in shrublands and longer in shrublands or forests regarding agricultural areas or degraded areas (F: 16.0, p < 0.0001). The results obtained would be useful to prevent/control fires and to preserve natural resources and human communities.