Spatiotemporal Variability of Burned Area over the Arctic–Boreal Zone during 2001–2016

The Arctic–boreal zone north of 50°N is one of the two major fire zones in the world. Fires in this region affect the local vegetation succession as well as the regional and global carbon cycle and climate. Previous studies have focused on fires in small regions or over a specific land cover type and individual extreme fire events; however, the spatiotemporal variability of the Arctic–boreal fires remains unclear. In this study, we comprehensively analyzed the spatiotemporal variability of the burned area in the Arctic–boreal zone from 2001 to 2016 based on three satellite-based global fire products: GFED4.1s, MODIS C6, and FireCCI51. Results show that during 2001–2016, the average burned area in this zone was 7.47±0.72 Mha/a, and large values for the burned area are mainly observed in locations including Alaska, central Canada, and south and central–east Siberia. The burned area exhibits large interannual variability, with similar magnitude and spatial pattern to the multiyear average. The annual burned area for forests demonstrates an upward trend in the entire Arctic–boreal region and Arctic–boreal North America, while that for croplands exhibits a downward trend in Arctic–boreal Europe. Arctic–boreal fires mainly occur during spring and summer seasons. However, the primary land cover types that burned are different. On a multiyear average, fires occurred mainly in savannas and forests in summer over the Arctic–boreal North America, in croplands in spring and forests in summers over the Arctic–boreal Europe, as well as in forests and shrublands in summers and croplands and forests in spring in the Arctic–boreal Asia. In years where the burned area is extremely large, the land cover types that burned in various regions are similar to the multiyear average results.