Wildfires and Trails: Q&A with WTA Field Programs Manager

2015 has been one of the worst wildfire seasons on record, and until the wildfires burning across Washington are out and the Forest Service begins to assess their damage, we won't know the full impact to hikers' favorite trails. But WTA has a lot of experience helping reestablish trails in burned forests. (Read about WTA's role in opening the popular Duckabush River trail after the Big Hump fire closed it.)

So, we sat down for five minutes with Alan Carter Mortimer, who is WTA's Field Programs Manager and who has decades of trails experience, to ask about the impact fires can have on trails and what helping a trail recover involves.

What kind of damage can a fire do to a trail?

In the short term, a lot of the trees that get burned will fall across trails. But fires can even generate such high winds that they can blow trees down in the midst of the firestorm.

If the root system is burned out, you'll get a lot of holes and cavities in the trail. When you go into these areas it's interesting how extensive the root systems are; you just don't have a concept until you see the spider web that's a foot or two feet deep all over your section of trail. You don't think about how much is underground that burns, and then you have to fix it, fill it in.

An Aug. 27, 2015 photo from the Kettle Complex Fire showing how the fire has weakened the root systems that hold trees in place. These create a hazard for firefighters and public traveling through the area. Credit: inciweb

The same thing happens to any kind of wood structures that you have in the area: bridges, puncheon, turnpike, and any kind of log retaining walls. They get burned, and then you have to rebuild them, and there's generally not a lot of material around to rebuild with.

You've also got a massive amount of erosion. What happens in high heat fires is that soil can become hydrophobic. It repels water. So not only do you loose vegetation that absorbs water and holds the soil, but the soil itself doesn't have the ability to absorb so much water which means a lot higher rates of runoff.

You touched on a few of the challenges of rebuilding a trail after a fire. Are there others?

WTA volunteers clear downed trees after the Big Hump burn on the Duckabush River trail. Photo by Meagan MacKenzie.

Until vegetation establishes itself, you're going to have to go in and reestablish your trail tread more frequently. Where as you used to be able to do it every 2-5 years, now you have so much material coming down off the hillside that you have to go in every year.

Fighting fires can also suck up the Forest Service budget for trail maintenance.

Plus, having to go in and log out 100 trees from a trail is really expensive. It takes a lot of time and resources.

Are there any benefits at all to trails?

For a trail, it may be good opportunity to reroute if you had a problem area that was too steep. But fires can have a lot of really positive impacts on forest ecosystems overall.

Why are trails sometimes closed so long after a burn?

To make sure the fire is completely out, that it's not going to flare up again. Short-term, there is the danger of hot spots. Long after the fire appears to be out, there is the danger of root balls and systems underground continuing to burn. There is a danger of people stepping through and getting burned.

Falling trees are a danger in the short and long term. As the years go by, the downfall does taper a little, but then trees that were killed but didn't have their roots burned will rot over time and begin to come down.

Is it true that trail maintenance tools evolved from wildland firefighting?

Ed Pulaski was a Forest Service ranger in Northern Idaho who combined an axe and a grubbing tool into one tool after the 1910 wildfires. It's the most standard firefighting tool, and we use it on the trails every week.

The other name for a McLeod is a fire rake. We use many of the same tools on trails as they do on a fire line.

Many trails and trail tools evolved from wildland firefighters. On the left, a crew fighting the Wolverine Fire (Photo by Kari Greer, USFS) and on the right, a WTA BCRT trail maintenance crew. (Photo by Austin Easter)