Spatiotemporal characteristics of wildfire frequency and relative area burned in larch-dominated forests of Central Siberia

Abstract

Wildfire frequency, relative area burned, and fire return intervals (FRI) have been studied in larchdominated forests along the transect from the southern (45° N) to the northern (73° N) distribution limits of larch stands based on analysis of satellite imagery (NOAA/AVHRR, Terra/MODIS; 1996–2015) and collection of tree cross cuts with fire scars. A significant increasing trend in fire extent (R2 = 0.50, p 55° N). The length of FRI increases from 80 years at 62° N to ~200 years at the Arctic Circle and reaches ~300 years near the northern limit of larch stands, showing a significant inverse correlation with the length of fire season (r =–0.69). In turn, the length of fire season, area burned and FRI are closely correlated with latitudinal variation in solar irradiance (r = 0.97, 0.81, and –0.95, respectively).