Trees are often killed even by low-intensity surface fires. Crown fires typically result in extensive mortality. Following fire, fire-killed black spruce trees release large quantities of seeds over a period of 1 to 5 years, resulting in abundant seedling establishment.
Numerous authors report that in boreal forests black spruce seeds in promptly following fire.
Fires occurring within this time frame have little effect on black spruce, as it quickly regenerates from seed. Moving northward from open woodlands to arctic treeline, the likelihood of successful black spruce seedling establishment following fire progressively diminishes. Where sparse seed production does occur, short-term climatic changes over a period of only 1 to 10 years could exhaust the seed population before a fire, or prevent seed germination after a fire. At treeline in northern Quebec, fires destroy or severely reduce black spruce and cause a shift toward arctic tundra. No seedlings were found on unburned surfaces or on scorched or charred feather mosses.