The occurrence of forest fires in Mexico presents an altitudinal tendency: a geospatial analysis

Fire has become one of the main disturbances in terrestrial ecosystems worldwide. It is known that elevation influences the occurrence of fire events; however, this variable has been poorly studied, although it is of particularly relevance to the Mexican topography. The objective of this research was to analyze the altitudinal distribution of forest fires in Mexico over a period of 11years. Elevation gradients were defined based on a Digital Elevation Model and the main ecoregions of the country: (1) shrubland and tropical forests (0-1000 masl), (2) grasslands (1001-2000 masl) and (3) temperate forests (>2000 masl). Each ecoregion was divided into Climate Research Units and the number of fires per unit was quantified. The G Getis-Ord statistic was applied in order to define the spatial patterns presented by the fire events. A relationship between the occurrence of fires and the El Nino Southern Oscillation phenomenon was also determined through a Pearson correlation. The results showed that the occurrence of fire events presented variability along elevation gradients, with elevation a determining factor in their occurrence. Gradient 3, with the highest elevation, had the greatest number of fires and also presented the largest area of fire event clustering. These results contribute to the knowledge of the spatial distribution of forest fires in Mexico and are of value to appropriate decision-making for effective fire management.