The spatial patterns of climate-fire relationships on the Mongolian Plateau

Abstract

Climate widely influences the geographical patterns of wildfires in terrestrial ecosystems. Understanding climate-fire relationships is crucial in exploring the response of wildfires to climatic conditions in different ecogeographic environments. However, how climate affects regional wildfires and which factors dominate the spatial patterns of climate-fire relationships are still poorly understood. Using satellite-based burned area data and climate datasets of the Mongolian Plateau, we analyzed the concurrent and antecedent climate-fire relationships; evaluated the spatial change characteristics of the climate-fire relationships along gradients of moisture, fuel, topography, and human activity; and estimated the ability of climate to explain fire dynamics to identify key factors mediating the spatial patterns of climate-fire relationships at ecoregion scales. The results showed that concurrent hot and dry and antecedent warm climatic conditions widely facilitated larger burned areas, and humid conditions increased the amount of burned areas in most arid ecoregions by controlling fuel accumulation. The strength of the climate-fire relationships changed along the environmental factor gradients, and the nature of climate-fire relationships shifted when variation in drivers exceeded the gradient thresholds. Wildfires respond differently to climatic conditions, and ecoregion-based models revealed that climate explained 21.53% of the variation in burned areas on average. These findings suggested that under universal arid environments, climate across multiple time scales shapes distinct local fire regimes by controlling fuel flammability and fuel accumulation, and vegetation productivity and moisture mediate the spatial patterns of climate-fire relationships across ecoregions. This study provides knowledge of climate-fire interactions in mid-latitude regions at ecoregion scales and facilitates policies for regional fire suppression.