Fire in Ecosystems of Boreal Eurasia: Ecological Impacts and Links to the Global System

Abstract

The circumpolar belt of the boreal zone stretches in two broad trans-continental bands across North America and Eurasia. The northern boundary of the zone corresponds to the July 13°C isotherm, while the southern boundary is limited by the July 18°C isotherm (Kuusela 1990). The boreal zone has been classified into three sub-zones, the maritime, continental and high-continental sub-zones. The maritime sub-zone has mean summer temperatures of 10–15°C, winter temperatures of 2–3°C, and annual precipitation of 400 to 800 mm. The continental sub-zone has long, cold winters with mean temperatures from -20 to -40°C, and summer mean temperatures from 10 to 20°C. The growing season is between 100 and 150 days, and annual precipitation ranges between 400 and 600 mm. The high continental sub-zone covers the largest portion of the boreal zone and is characterized by more extreme winters and milder summers. In Europe, the influence of maritime airmasses decreases from west to east, reaching West Siberia as far as the Yenisei river. East Siberia and the Far East are characterized by high-continental climate.