Black trees, green trees, ash pits and other hazards after a wildfire

kettle fire
A void is left under this tree after its roots partially burned away in the Kettle Fire in northeast Washington state this summer.

Wildfires in forested areas can leave behind a lot more than ashes and burnt limbs. Trees that are still standing, as well as the remains of those consumed by flames, can pose dangers to workers, hikers, hunters, trail riders and others for months if not years after a wildfire.

Ash pits: Ash pits are created by when trees and stumps and their root systems are burned away. Insulated by layers of ash and debris, embers remaining inside these pits can stay hot enough to burn flesh for weeks. Falling into an ash pit or stepping into one can cause serious burns, so warn your family and neighbors to keep clear of these pits and make sure that children and pets are kept away, too.

Black trees: With so many thousands of acres of forestland in Washington state burned this summer, there will be an abundance of fire-killed trees to watch out for on the landscape. The US Forest Service’s Forest Health Protection program warns that conifer trees, especially firs, that died in a wildfire are especially susceptible to toppling over about three to five years after the fire. Keep clear of these snags, and be especially alert whenever the wind blows or the snow falls.

Green trees: Monitoring by the US Forest Service reveals that surviving trees — those with green crowns but visible fire damage — may start to fail (fall or drop large limbs, that is) in as little as three years after a fire. If the bark on the trunk has been burned off or scorched by very high temperatures completely around the circumference, the tree is unlikely to survive. The failure rate of green trees with fire damage increases dramatically by the fourth year after a fire as additional damage from opportunistic wood-dwelling insects takes it toll.

If any of these hazards are present, approach a landscape cautiously and consider an alternate route.

If these hazards exist on your property, seek advice from a consulting forester or a certified arborist. Washington State University Extension’s wildfire website lists many resources for farm and woodland owners. The University of Idaho Extension publication “After the Burn” digs deep into post-wildfire land care, from damage assessment to salvage logging to replanting ground cover and new trees.

Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter

One thought on “Black trees, green trees, ash pits and other hazards after a wildfire

Comments are closed