A nice fire in the woodstove on a winter day is a welcome thing. A big wildland fire in summer is another. The Funny River Fire was the biggest fire in Alaska in 2014. Conditions were ideal in late May for a fire on the Kenai: low humidity of just 20 percent, a dry wind from the north, and an abundance of dry grass. By the time the human-caused fire was burned out, the burn encompassed almost 200,000 acres. Fish and Game biologist and forester Sue Rodman explains how and why the fire was so extensive.
"Most of the black spruce there were over 60 years old and they were prime for burning. They're 30 feet tall or more, they have limbs that go all the way to the ground, and the understory vegetation is cranberry and blueberry that burns really well."
Most trees are mostly water; the wood and bark weigh less than the water inside the tree. The moisture-to-weight ratio is 200 percent in most live trees, a cottonwood is 300 percent. In spruce the moisture to weight ratio is just 60 percent. There's a reason spruce makes good firewood.
"Spruce trees have less moisture in them when they're alive than most trees do when they're dead," Rodman said. "You combine that low moisture with the volatile contents in the sap and needles, and they burn great."
A 200,000 acre burn conjures the image of a moonscape, but it's not all burned. Different forest types, wet areas, creek and rivers and terrain features create a mosaic of burned and unburned areas, which is good for wildlife and helps regeneration.