Video - Defining old growth

Environmentalists, foresters disagree about what should be cut and why

By Dylan J. Darling / The Bulletin / @DylanJDarling

Published Sep 1, 2013 at 05:00AM

A mix of standing dead trees, logs on the ground and massive ponderosa pines defines the stand of trees near Pringle Falls, south of Bend. For Ron Boldenow, Oregon Society of American Foresters chairman, this is old growth.

A similar stand of towering ponderosa pines close to Camp Sherman is littered with snags and fallen logs. For Karen Coulter, a long-time forest protection activist, this is old growth.

A diversity of trees, small to large, fallen and dead, standing and growing, is also found in a ponderosa pine stand near Sunriver. For Chuck Burley, timber manager at the Interfor mill in Gilchrist, this is old growth.

While opposing sides to timber debates may agree on some details on the definition of old growth, they are not in complete harmony. There are disagreements about the size and age of woods worthy of the label. And there are ongoing arguments about how best to manage and maintain the remaining old growth stands around Central Oregon.

“Old growth depends on who you talk to and it really depends on the systems, the forest types,” said Mike Simpson, ecologist at the Deschutes National Forest.

Politics, social values and economic context all come into play when defining old growth. There are hundreds of definitions for the term.

“We are not about saying one is right and one is not,” Simpson said.

Size and age

For most of the woods east of the Cascades in Oregon, the federal standard for determining if a tree should be protected from logging as old growth is its diameter. Trees larger than 21 inches are typically spared the saw.

Coulter, director of the Blue Mountains Biodiversity Project in Fossil, agrees with the standard, saying it is scientifically sound. For ponderosa pine she said 21 inches in diameter often means a tree is at least 150 years old. For decades her environmental group has fought to protect such trees in appeals, lawsuits and objections to U.S. Forest Service plans.

“We are lacking large trees on the landscape,” she said.

Trees 21 inches in diameter and bigger, and 150 years old or older, are old growth, said Tim Lillebo, eastern Oregon field representative for Oregon Wild. The statewide conservation group is based in Portland but Lillebo works out of Bend.

While Coulter and Lillebo expand their definition of old growth to include the surrounding trees and complexion of the woods, they argue for the protection of trees 21 inches in diameter and larger for the sake of saving old growth.

Coulter also calls for preserving trees close to the size that are on their way to becoming old growth.

Burley and others with the timber industry disagree with diameter as a measure for age and whether a tree is old growth. The critics include Tom Partin, president of the American Forest Resource Council in Portland.

“I don't believe old growth is dictated by age as much as (it) is characteristics of the tree,” Partin wrote in an email.

He said a 250-year-old ponderosa pine near Bend could range from 10 inches to 40 inches in diameter, depending on how much competition there is among trees in a stand.

“An old growth tree in my opinion, especially in pine, is one that has quit growing in height — tops have flattened out and bark has big flat platelets,” he wrote.

Burley doesn't like using age to define old growth. Having been involved in timber debates for decades, Burley said the age once used to determine old growth was 350 years. That has decreased to 150 years.

“I mean the goal post has been shifting all the time,” he said.


Defining old growth in terms of size and age is contentious, but even environmentalists and timber interests find agreement when describing the setting of an old growth stand in Central Oregon. The stands near Pringle Falls, Camp Sherman and Sunriver all have a combination of old trees, dead trees known as snags, and fallen trees.

Old growth stands vary with the type of trees and location, with old growth on the west side of the Cascades dominated by Douglas fir and old growth on the east side flanks mainly ponderosa pines. Boldenow, Coulter and Burley all choose ponderosa pine woods as examples of old growth here. The stands all included a mix of openings, single trees and bunches of trees.

Boldenow starts his description of old growth with its structure, saying it must be complex and include the different elements.

“It's not about an individual tree,” he said. “It's about a group of trees.”

Steve Fitzgerald, a forestry researcher with the Oregon State University Extension Service in Redmond, was with Boldenow in the visit to the woods by Pringle Falls and agreed with him.

“One tree doesn't tell the full story,” he said.

Coulter, the environmentalist, and Burley, the logger, also had similar descriptions.

“It is important to have snags, logs and big trees,” Coulter said.

Burley has the same list in his description of old growth.

“It's a stand structure,” he said.


Along with his post for the Oregon Society of American Foresters, Boldenow is a forest technology instructor at Central Oregon Community College. He teaches his students how frequent wildfires shaped old growth in Central Oregon, thinning the stands, reducing underbrush and creating openings.

Much of the old growth around Bend that was here a century ago is gone, cut to become lumber in the mills that once were the heart of the town. What remains has largely been protected from fire for decades. The question is what, if anything, should be done now.

This is where Coulter and Burley don't agree. They have differing opinions on how the U.S. Forest Service should manage old growth in Central Oregon.

Coulter doesn't mind underbrush thinning and some burning but she wants diseased trees, snags and logs left in place, in order to decay and pass nutrients on to future trees. She also said fires that level entire stands are a part of the cycle of forests.

In large trees with flat tops, Coulter sees old trees that have now started growing out rather than up. Such flat-topped trees are likely diseased or dying, Burley said. He contends they should be cut.

There is a constant pressure by the timber industry to log big trees, Coulter said.

Burley said he wants the Forest Service to allow loggers to take down large, dying trees, even trees over 21 inches in diameter, to open up old growth stands. Doing so will give the healthy trees more room to grow and less competition for sun and water. He also says thinning out younger trees crowding old growth stands would prevent destructive wildfires and improve the overall health of the old growth.

“The competition hurts these trees,” he said.

“I don't believe old growth is dictated by age as much as it is characteristics of the tree. In the ponderosa pine around Bend you can have 250-year-old trees that are 40” in diameter and also only 10” in diameter if they have been growing in thick stands with little light and moisture.”

What does 'old growth' mean?

“Old growth” has a range of definitions, depending on who does the defining and a number of other variables.

The Bulletin surveyed experts in forestry, environmentalists and timber interests to gather their thoughts on what “old growth” means.

Here is what they had to say:

Foresters have technical definitions of old growth, but “... for the general public, basically any area with some big trees is thought of as old growth.”

— John Bailey, associate silviculture and fire management professor, Oregon State University

“Old growth really doesn't refer to an age, but a set of ecological functions. These include large trees (30” plus), a variety of sizes, a stand that has patchiness to it with openings rather than an unbroken sea of similar trees, dead trees, downed log.”

—Mike Cloughesy, Oregon Forest Resources Institute

“(Oregon Department of Forestry) generally prefer to speak of 'older forest structure,' since the term 'old growth' is interpreted in so many different ways by the public.”

—Rod Nichols, ODF spokesman

“... We can't just focus on large trees, we have to consider the whole suite of features, including dead trees.”

—Doug Heiken, Oregon Wild conservation and restoration coordinator

“There are a couple of different ways that people (identify) old growth, like by the age, the size, but it is mostly the characteristics.”

—Tim Lillebo, Eastern Oregon field representative, Oregon Wild

“I think it's safe to say old growth is not just a single tree. There are old trees, yes, and there are large trees. But large does not necessarily mean old nor does old necessarily mean large.”

—Chuck Burley, timber manager, Interfor mill in Gilchrist

“Note that even the definition of an old-growth forest is complex and refers to a forest rather than a tree. Foresters are reluctant to label an individual tree as 'old-growth.' Old-growth is about an entire stand of trees, not just a few old trees.”

—Ron Boldenow, chair Oregon Society of American Foresters