After a Wildfire: Which Burned Trees Will Live?

What should you do first after a fire?

Deal with the trees that could hurt someone. Montana DNRC's tree planting and restoration page advises hiring a qualified arborist when individual trees after a disturbance are a threat to life or property, and points to the International Society of Arboriculture's directory of certified arborists.

A burned tree can fail, especially if fire burned into the roots or the base. Stay out from under burned trees in wind, keep people and vehicles away from trees leaning toward driveways and buildings, and get those assessed first. Everything else can usually wait for a careful look, and often should.

Why do some scorched trees survive and others die later?

Because fire damages different parts of a tree, and the tree can survive losing some of them. Montana State University Extension's MontGuide on fire-resistant plants explains that ground fires kill the phloem and cambium, the tree's living layer, often partly or fully girdling the trunk, but that new tissue laid down the following spring lets many damaged trees survive. Crown fires destroy foliage, which cuts the tree's ability to make food and leaves it more open to winter damage and pests. Young trees are hit harder than older ones.

The same MontGuide notes that species with thick, corky bark, including western larch, ponderosa pine and Douglas-fir, often escape severe damage, while thin-barked species such as subalpine fir, Engelmann spruce and lodgepole pine, along with many younger trees, are more likely to be killed by ground fire. That single fact explains a lot of what owners see on a burned slope here.

What is the best single sign that a tree will die?

How much of the crown was killed. A USDA Forest Service Rocky Mountain Research Station review of post-fire mortality research on ponderosa pine and Douglas-fir (Fowler and Sieg, 2004) found that crown scorch volume, the share of the live crown killed by heat, was the most effective, easiest to use and most popular measurement for predicting death in both species. Several studies showed it helps to add a measure of stem damage, and direct checks of the cambium near the base of the tree are widely used for Douglas-fir.

Estimate crown damage by volume, not by height, and look from more than one side. Most conifer crowns are widest at the bottom, so scorch that climbs a third of the way up the crown has usually taken more than a third of the foliage. The review found volume a better predictor than scorch height.

Is scorched different from burned?

Yes, and it matters most for pine. Oregon State University Extension's 2025 guide, Will my tree live?, built on Forest Service research by Hood and others, separates needles that were scorched brown by heat from needles that were consumed or blackened by flame. Scorched needles can hide live buds. For ponderosa pine assessed before spring bud break, the guide says the tree is likely to die if 85 percent or more of the needles are scorched while less than 10 percent are blackened, or if more than 40 percent are scorched where more than 10 percent are blackened.

After bud break, the guide shifts to whether new growth appears, using a threshold of 70 percent of crown volume killed with no new growth. In plain terms: a brown pine in fall is not necessarily a dead pine. Wait for spring and look for new shoots at the branch tips.

What are the thresholds for other species?

The Oregon State guide lists thresholds above which a tree has a greater than 50 percent chance of dying. For Douglas-fir it is more than 65 percent of crown volume killed. For lodgepole pine it is 40 percent or more. For western larch with needles on, it is 80 percent or more of the crown length. It also lists bark char thresholds by species and tree size, and some values change with diameter, so check the original table for your tree. These thresholds were compiled for Oregon and Washington, but they cover the same species that grow in the Missoula and Bitterroot valleys.

For the Northern Rockies specifically, the Forest Service publishes RMRS-GTR-199 (Hood and others, 2007), which models the probability of Douglas-fir death and of Douglas-fir beetle attack after fire from injury and stand measurements. It was developed from data in Montana and Wyoming and includes a photo field guide. A forester or arborist can use it on high-value firs.

How do you check the bark and cambium?

Look at the base first. The Oregon State guide treats deep char around the base and exposed or charred roots as warning signs, and notes that char on thin-barked species is a reliable sign of dead cambium while char on thick bark is less reliable. A ponderosa can carry black bark over live tissue; a lodgepole usually cannot.

The direct test is to look at the cambium under the bark at several points around the base: the Fowler and Sieg review describes healthy cambium as white and spongy, while heat-killed cambium quickly turns brown and smells sour. This wounds the tree, so it should be done sparingly and by someone who knows what they are looking at. The Fowler and Sieg review notes that this direct cambium check near the base is widely used in Douglas-fir.

How long should you wait before deciding?

Often one to two growing seasons for trees that are not hazards. The Fowler and Sieg review found that the studies tracking mortality longest showed most post-fire mortality occurs by the end of the second year after the fire. The Oregon State guide says moderately injured trees are less predictable and recommends careful assessment or waiting to see how the tree responds, while heavily injured trees are generally likely to die.

Waiting is a decision with a cost. A tree that dies in year two may need removal then, and a dead tree near a house adds fuel and a falling hazard. Waiting makes sense for trees away from structures, where losing the bet means removing the tree a year later, not a roof repair.

What role do bark beetles play after a fire?

A large one. The USDA Forest Service's 2025 pine engraver management guide says fire-scorched trees are highly attractive to pine engravers because scorching destroys the cambium and weakens defenses, and that infestation in scorched trees is most likely within two years of a burn and tapers off in the third. The Oregon State guide adds that boring dust and attack signs, other than from red turpentine beetle, on more than half the trunk's circumference mean the tree will die regardless of its fire injury.

For Douglas-fir, the GTR-199 models exist precisely because Douglas-fir beetle attacks fire-injured firs. Watch for reddish boring dust in bark crevices and at the base through the first two summers. Our guides to pine engraver and slash and Douglas-fir problems describe the signs.

Should all fire-killed trees be removed?

Not necessarily. The Oregon State guide frames the decision around goals and risk tolerance: low tolerance near structures, roads and places people use, where trees likely to die should come out, and higher tolerance in the woods, where partly decayed trees can be valuable wildlife habitat. It also notes that fire scars can let decay into the trunk, raising the risk of breakage years later.

Dead trees left standing near a home are both fuel and a falling hazard; our guides to dead snags near homes and beetle-killed trees and fire cover that tradeoff. Removal near buildings and lines is hazard tree removal, and trees near power lines need qualified line-clearance work.

Who can help assess burned trees?

DNRC's restoration page lists DNRC service foresters, who help private landowners with planning, and MSU Extension's wildfire severity photo-guide for judging how hard a site burned. It also notes that Burned Area Emergency Response (BAER) reports cover federal land only but can show what is recommended on neighboring federal ground. For individual trees near homes, it points owners to a qualified arborist.

Our tree health and risk assessment is done by an ISA Certified Arborist and helps sort out which burned trees need to come down now and which can be watched. After the trees come the ground and the yard: see erosion and flooding after a fire and replanting after wildfire.

Where this fits

Recovery is the last chapter of our Montana Wildfire Guide, and the trees are where it starts. Our fire mitigation and tree services crews handle hazard removal, cleanup and the thinning that helps the survivors. Call HJ Property Care & Tree Service at (406) 215-7319 or request a free estimate and we will walk the property with you.

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