Thousands of trees in the watershed will be cut down and removed via helicopter next spring to try to restore the forest to the way it was 150 years ago, when wildfires naturally picked off struggling trees, city officials said Tuesday.

Thousands of trees in the watershed will be cut down and removed via helicopter next spring to try to restore the forest to the way it was 150 years ago, when wildfires naturally picked off struggling trees, city officials said Tuesday.

The helicopter thinning, the next step in Ashland's Forest Resiliency Project, will involve the removal of mostly Douglas firs from more than 1,000 acres in the lower watershed, said Chris Chambers, Ashland Fire & Rescue's forest resource specialist.

"In terms of the whole watershed, it is a unique time we've come to," he said. "Since fire hasn't been functioning in its natural role, because of fire suppression efforts over the past 100 years, we're going to step in, so that eventually fire can take care of the forest like it used to."

Because fire hasn't swept through most parts of the watershed in 100 or 150 years to clear out small trees and brush, a wildfire now could be catastrophic, burning even old-growth trees and threatening nearby homes, Chambers said.

On Saturday, the city will take local residents to the first 588-acre plot that is scheduled to be thinned next spring, as long as contractors are available. The tour will cover Block 1 of the watershed, located at the end of Granite Street and west of Ashland Creek to Forest Service Road 300.

The 9 a.m. to 1 p.m. tour also will include a visit to a portion of the watershed where the city is hoping to conduct a controlled burn this spring, if weather conditions allow.

People who attend the tour will be invited to give feedback on the helicopter-thinning project. The city will analyze the comments received and possibly use them to adjust the plans, Chambers said.

"This is the first chance to see the impact of the project on the ground," he said. "We want the public to have an opportunity to see what's going to happen and to get an idea of the actual trees that are going to be cut."

Primarily Douglas firs will be removed, because they are ubiquitous in the watershed and aren't as fire-resistant as oaks and pines, Chambers said.

"Douglas firs are sensitive to fire when they're younger, and with lack of natural fire in the ecosystem, that tree in particular has grown into forests that used to be more open," he said. "There are a lot more Douglas firs now than there would have been 100 or 150 years ago."

The trees will be cut down and then lifted out of the watershed by a helicopter and taken to a mill. The exact number of trees to be toppled hasn't been determined yet, Chambers said.

The helicopter-thinning plan for Block 1 already has been reviewed by biologists, forest ecologists, the U.S. Forest Service and other experts.

In about a month, the city will hold a tour of Block 2 of the watershed, which also will be thinned via helicopter next year and is located above and south of Block 1.

The helicopter thinning of both blocks is expected to cost $1.3 million, Chambers said. The trees will be sold to a yet-undetermined mill, and that money will help offset the cost.

"These trees are going to be taken to a mill, so they have commercial value to them, but of course that's not the reason we're doing the work," Chambers said.

The remainder of the cost will be paid for out of the $6.5 million in federal stimulus money the resiliency project received.

The city last thinned a portion of the watershed via helicopter seven years ago, Chambers said.

The resiliency project is led by the city, the U.S. Forest Service, the Lomakatsi Restoration Project and The Nature Conservancy. The project aims to restore the health of the forest, prevent devastating wildfires and secure Ashland's water supply.

Those attending Saturday's tour should meet at the ice rink parking lot on Granite Street for the tour in city-provided vehicles. Attendees are asked to wear sturdy shoes or boots, and bring a snack and water.

To sign up to attend, call 541-552-2286 or email taylora@ashland.or.us. A summary of the helicopter-thinning project can be viewed online at ashlandwatershed.org, where people also can submit comments.

Contact reporter Hannah Guzik at 541-708-1158 or hguzik@dailytidings.com.