The reason for the tree thinning in Jefferson County open spaces

JEFFERSON COUNTY, Colo. (KDVR) — As things start to heat up over the next few days, wildfire risk in our state is increasing.

Jefferson County Open Space has been trying to stay ahead of catastrophic fires by pre-thinning trees near communities. But some environmental groups have been calling out the method.

Pre-thinning trees is a practice Jefferson County has been using for several years. Their forest health plan helps them identify which areas to work in.

“That’s where we start everything from,” said Steve Murdock, natural resource team leader for Jefferson County Open Space. “Once we’ve identified those areas, then we go out and do what’s called a pre-thinning inventory, where we go out and we measure tree height, tree size, the numbers of trees, things like that.”

Murdock said a lot of research goes behind how many trees and which kinds of trees they thin out.

“That’s run through our wildlife ecologists, our botanists, to get their feedback on how the wildlife and the plant species are going to respond, and that entire picture together informs our treatment,” Murdock said.

The process is all to help prevent a major wildfire from sparking and getting out of hand, which can happen if there are a lot of trees close together.

“When a fire starts naturally, instead of creeping across the ground and burning around the thick bark of the larger trees, it catches the needles of the smaller ones, and then runs up the ladder and gets into the crown of the trees. And then we have a running crown fire,” Murdock said. “That is what we’re trying to prevent.”

Envrionmental group questions pre-thinning trees

However, some environmental groups have disputed this method, first saying that thinning a forest is not effective at keeping communities safe.

“The studies show that that does not help protect communities, and in fact, what they’re doing is making the forest hotter and drier and then they’re opening it up to winds,” said Josh Schlossberg, Colorado organizer for Eco-Integrity Alliance . “And the winds are what spread the fire.”

Schlossberg said the last time he was at Alderfer/Three Sisters Park, where some of the thinning has taken place, he noticed there were older trees that had been cut down.

“Just last week, I found they’re cutting trees over 200 years old. I counted one tree cut to 211 years old. So that doesn’t even abide by their own forest health plan,” Schlossberg said.

He said older trees tend to be more fire-resistant than the younger trees, growing a thick bark that has adapted to withstand fires in the past.

Population growth near forests affects wildfire patterns

Jefferson County Open Space said that was how the system worked hundreds of years ago — before people began to settle in these areas.

“Once we started moving into the area and putting out fires during that aggressive fire suppression period, those trees were allowed to unnaturally continue to grow in the absence of fire,” Murdock said.

He said this means there is a much higher density of trees than what normally should be there.

“There are some trees out there that are 150, maybe even 200 years old that would have been thinned out by a historic fire that were not,” he said. “That means, unfortunately, we have to cut some larger trees from time to time.”

Murdock said they still look out for old-growth trees that still exhibit those characteristics, which is where their foresters come in.

“Our foresters identify those trees that are (exhibiting) those traits. We mark them to protect them. We are not removing those old-growth trees at all,” Murdock said.

Schlossberg said he has heard from some people who now refuse to hike in some of these open spaces because they no longer look the same.

“It’s barely a park anymore. It’s just a sacrifice zone. And I did speak to somebody who specifically said to me, ‘We’ve been coming here for years, we’re never coming back,'” Schlossberg said.

‘We kind of equate forest management work to open heart surgery’

Murdock acknowledged the pre-thinning can look intimidating, but he said it is better than looking at a burn scar if a giant wildfire comes through and leaves nothing but matchsticks.

“We kind of equate forest management work to open heart surgery. Immediately after that open heart surgery, you got a big nasty scar, bruising, it looks messy. But over time, that slowly heals, the bruising goes away, and you’re better off for it. The forests are in the same position,” Murdock said.

Other concerns Schlossberg presented were a lack of communication and a lack of willingness to work with Eco-Integrity Alliance and others who do not believe this method of tree thinning works.

“We’re not saying that they should only be taking our perspective. We’re saying please incorporate our perspective, participatory democracy. We go to their town hall meetings, they don’t let us speak. It’s been really, really difficult,” he said.

However, Jefferson County Open Space said they are always open to listening to the community and encourage anyone with questions to give them a call.

“It’s a big change, and we’re here to answer questions. It’s complicated,” Murdock said. “And just try to help move people along to appreciate what a healthy forest actually looks like.”

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