Forests of

Western Oregon:

An Overview

Sally Campbell, Dave Azuma,

Dale Weyermann

United States

Department of 

Agriculture

Forest 

Service

Pacific Northwest

Research Station

PNW-GTR-525

April 2002 Revised 2004
Authors

Sally Campbell is a plant pathologist, Dave Azuma is a research forester, and Dale Weyermann is geographic

information system manager, U.S. Department of Agriculture, Forest Service, Pacific Northwest Research

Station, P.O. Box 3890, Portland, OR 97208-3890.

Cover: Southwest Oregon Photo by Tom Iraci. Above: Oregon Coast Photo by Don Gedney
Forests of

Western Oregon:

An Overview

Sally Campbell, Dave Azuma, and Dale Weyermann

U.S. Department of Agriculture Forest Service

Pacific Northwest Research Station

Portland, OR

April 2002
State Forester’s Welcome

Dear Reader:

Western Oregon has some of the most productive forest lands in the world, important for sustainable supplies of 

fish and wildlife habitat, recreation, timber, clean water, and many other values that Oregonians hold dear.The

Oregon Department of Forestry and the USDA Forest Service invite you to read this overview of western Oregon

forests, which illustrates the importance these forests have to our forest industries and quality of life.This publication

has been made possible by the USDA FS Forest Inventory and Analysis (FIA) program, with support from the

Oregon Department of Forestry.

The Oregon Department of Forestry and FIA have a long history of collaboration that has benefited both agencies

and others who use the data and the information developed from it.This report was developed from data gathered

by FIA in western Oregon’s forests between 1994 and 1997, and has been supplemented by inventories from

Oregon’s national forests and the Bureau of Land Management.We greatly appreciate FIA’s willingness to collect

information in addition to that usually collected in forest inventories, data about insects and disease, young stands,

and land use change and development.

Developing current and historical information across all ownerships and forest land types is critical to the Oregon

Board of Forestry, which has embarked on an effort to define the concept of forest sustainability and to assess the

sustainability of Oregon’s forests.These data will be used in monitoring changes in forest conditions, in projecting

future forest conditions, and in developing benchmarks against which we can assess Oregon’s progress in achieving

forest sustainability.

As we move down this path toward ensuring the sustainability of social, economic, and environmental values from

forests, it is critical that we develop a consistent knowledge base—common measurements and standards by which to

evaluate sustainable forest management locally, statewide, and nationally.This inventory helps develop that knowledge

base, and as such, it will be extremely useful in educating Oregonians and others about Oregon’s forest resources.

I encourage you to review this material, use it, and if possible, visit Oregon’s forests for yourself.We would love 

to see you here.

James E. Brown

James E. Brown

State Forester
Highlights

This publication provides highlights of forest inventories and surveys from 1993 to 2000. It presents both 

traditional and nontraditional information about western Oregon’s forests.

• The amount of forest land in western Oregon has changed little since the earliest inventory in 1930.

• About 80 percent of western Oregon is forested.

• Fifty tree species were tallied in forest inventories during the 1990s, with Douglas-fir the 

predominant species in all ecological units in western Oregon.

• About 52 percent of western Oregon forest land is managed by the Forest Service, BLM, and other 

federal agencies; about 41 percent is privately owned; and the remaining 7 percent is managed 

by the Oregon Department of Forestry and other nonfederal public agencies.

• Average annual growth of trees on nonfederal lands in western Oregon is greater than the average 

amount of mortality and harvesting.

• One-third of inventory plots on nonfederal lands have one or more noxious weeds.

• Down wood and snags are important forest components and were tallied in the 1993-97 

inventories.

• Western spruce budworm, bark beetles, root diseases, dwarf mistletoes, and Swiss needle cast have 

affected many acres of forest land in western Oregon in recent years.

• Lichens, as indicators of air pollution, climate, and forest age and structure, have been tallied on 

a portion of inventory plots beginning in 1998.

• No ozone injury has been detected on sensitive forest species in western Oregon since ozone 

monitoring began in 1998.
Contents

1 Introduction

3 What Is the History of Western 

Oregon Forests?

6 How Much of Western Oregon Is

Forest and Where Is It?

8 What Trees Grow in Western Oregon?

12 Who Owns Western Oregon’s Forests?

14 How Old Are Trees in Western

Oregon?

16 What Is the Volume of Wood in

Western Oregon?

17 How Fast Are Trees Growing, Dying,

and Being Removed in Western 

Oregon?

19 How Much Dead Wood Is in Western 

Oregon Forests?

21 What Insects and Diseases Are in

Western Oregon Forests?

23 What Noxious Weeds Are Most

Common and Where Are They

in Western Oregon Forests?

24 What Are the Results of Lichen

Monitoring in Western Oregon?

25 Is Ozone Damaging Forest Vegetation

in Western Oregon? 

26 For More Information

27 Common Name/Scientific Name

Tree List
Mount Hood

Photo by Paul Dunham 

Abstract

Campbell, Sally; Azuma, Dave;Weyermann, Dale. 2002. Forests of western Oregon: an overview.

Gen.Tech. Rep. PNW-GTR-525. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific

Northwest Research Station. 27 p.

This publication provides highlights of forest inventories and surveys from 1993 to 2000. It presents both traditional

and nontraditional information about western Oregon’s forests.The amount of forest land in western Oregon has

changed little since the earliest inventory in 1930.About 80 percent of western Oregon is forested. Fifty tree species

were tallied in forest inventories during the 1990s, with Douglas-fir the predominant species in all ecological units 

in western Oregon.About 52 percent of western Oregon forest land is managed by the Forest Service, BLM, and

other federal agencies; about 41 percent is privately owned; and the remaining 7 percent is managed by the Oregon

Department of Forestry and other nonfederal public agencies. Growth of trees in western Oregon exceeds the

amount removed by harvest and mortality. One-third of inventory plots on nonfederal lands have one or more 

noxious weeds. Down wood and snags are important forest components and were tallied in these last inventories.

Western spruce budworm, bark beetles, root diseases, dwarf mistletoes, and Swiss needle cast have affected many 

acres of forest land in western Oregon from 1987 to 2000. Lichens, as indicators of air pollution, climate, and forest

age and structure, have been tallied on a portion of western Oregon inventory plots beginning in 1998. Monitoring

for ozone injury on several sensitive forest species also was begun in 1998; no ozone injury has been detected in

western Oregon.
Errata for PNW-GTR-525

The following changes have been made in this document.

Publication: Forests of Western Oregon: An Overview, PNW-GTR-525, April 2002

Authors: Sally Campbell, Dave Azuma, Dale Weyermann

Highlights, 3rd page, 5th bullet:

Change sentence to read: Average annual growth of trees on nonfederal lands in western

Oregon is greater than average annual amount of mortality and harvesting.

Page 1: Corrected footnote 1:

Oregon Natural Heritage Program and Oregon Department of Fish and Wildlife 2000:

adapted from Bailey, R.G. 1980 (Ecoregions of the United States. Misc. Publ. 1391.

Washington, DC: U.S. Department of Agriculture, Forest Service) and Omernik, J.M. 

1987 (Ecoregions of the conterminous United States map [1:7,500,000]. Annals of the

Association of American Geographers. 77(1): 118-125). 

Page 1: Corrected Source (for map):

Oregon Natural Heritage Program and Oregon Department of Fish and Wildlife 2000. 

See footnote 1. 

Page 16, first paragraph, 3rd sentence: Change the following sentence from:

“The forests of western Oregon have about 75 billion cubic feet of timber...” to:

“The forests of western Oregon have about 78 billion cubic feet of timber...”

Page 16: Graph at bottom of page, Timber Volume on Forest Land 
Page 18: Annual Mortality, Removals, Growth, and Total Volume graph 

Page 18: Ratio of Growth to Mortality + Removals graph 

1

THIS REPORT DESCRIBES THE FORESTS OF WESTERN OREGON TODAY. We present several 

different aspects of western Oregon forest land:Where it is, how old it is, who owns or manages it, how 

much wood volume is present, what tree species are present, and where it is being affected by insects, diseases,

and air pollutants.

We present the information organized by Bailey’s1 ecological units that delineate relatively homogeneous 

landscapes by topography, hydrology, and climate. In western Oregon, we use the following ecological units:

■ Oregon Coast Range ■ Willamette Valley 

■ Western Cascades ■ Klamath Mountains

1 Oregon Natural Heritage Program and Oregon Department of 

Fish and Wildlife 2000: adapted from Bailey, R.G. 1980 (Ecoregions 

of the United States. Misc. Publ. 1391.Washington, DC: U.S. Department of Agriculture, Forest Service) and Omernik, J.M. 1987 (Ecoregions of the conterminous United States map [1:7,500,000].

Annals of the Association of American Geographers. 77(1): 118-125.

Introduction

Source: Oregon Natural Heritage Program and Oregon Department of Fish and Wildlife 2000. See footnote 1.

Ecological units 

of western Oregon

➢

N
Most of the information in this report is from three sources: the 1994–97 USDA Forest Service Forest Inventory

and Analysis (FIA) inventory on state and private lands, the 1993-96 inventory on national forests, and the 1997

inventory on USDI Bureau of Land Management (BLM) lands.We also include information from the 1997–2000

forest health monitoring plots (now part of the FIA plot network), and from forest insect and disease aerial surveys

between 1987 and 2000.With the exception of the aerial surveys where forest condition is observed and recorded

from the air, all other data are collected by field crews visiting permanent ground plots.

Two terms are commonly used to describe forested land – “forest land” and “timberland.”

• Forest land (15.3 million acres in 1997 in western Oregon) is a more encompassing term that includes all land

that is at least 10 percent covered by trees of any size, greater than 1 acre in area, and at least 120 feet wide.

• Timberland (13.8 million acres in 1997 in western Oregon) is a portion of the forest land (described above) 

that produces (or is capable of producing) more than 20 cubic feet per acre of industrial wood products each 

year under natural conditions, is not withdrawn from timber use, and is not developed for nonforest uses.

Areas included in forest land but excluded from timberland are national and state parks, nature preserves, wilderness

areas, and urban forests (such as cemeteries and city parks).Also, because of agency policies such as the Northwest

Forest Plan and riparian reserves, all federal lands meeting the above definition of timberland may not be equally

available for timber production.

2

Inventory field crew

gathering data. Photo 

by Tom Iraci
FOR CENTURIES BEFORE EUROPEAN SETTLEMENT 

of the Pacific Northwest, the primary agents of forest change were

fire, wind, volcanic activity, insects, and disease.To a much lesser extent,

native people also modified the vegetation of western Oregon—both

accidentally and deliberately. In prairie areas (such as the Willamette

Valley) and adjacent dry Douglas-fir forests, they set fires for herding and

to promote growth of berries, roots, and other native crops. Small settlements along rivers, bays, and estuaries altered local topography, vegetation, and wildlife.2

In the mid-1800s, Euro-Americans began to settle in western Oregon.

They lit fires to clear land for grazing, agriculture, and town sites.They

altered riparian areas by trapping and virtually eliminating beavers. In 

the more forested areas of the Coast Range, western Cascades, and the

Klamath Mountains, extensive timber harvest, grazing and ranching,

mining, and dam construction significantly altered the forests of western

Oregon. Fires were used to remove slash after logging; some of there 

fires escaped and resulted in large forest fires.3

2 McNab, H.W.;Avers, P.E., comps. 1994. Ecological subregions 

of the United States: section descriptions.Washington, DC: U.S.

Department of Agriculture, Forest Service.

3 Agee, J.K. 1993. Fire ecology of Pacific Northwest forests.

Washington, DC: Island Press. 493 p.

3

The Tillamook Burn was one of the largest 

forest fires in western Oregon’s history. Oregon 

Historical Society Photo

Significant forestry events 

in western Oregon 

1829: Oregon City lumber mill—one 

of Oregon’s first sawmills, established by

Dr. John McLoughlin on the Willamette

River. By 1870, there were 173 sawmills

in Oregon. In 1885, the first Northwest

paper mill was built on the Columbia

River at Camas,Washington.

1905: The USDA Forest Service is 

created—the purpose of this new federal

agency was to conserve forest resources

and stabilize markets.

1930: First forest inventory in western

Oregon—mandated by McSweeneyMcNary Act of 1928.

1933: Tillamook Burn—a lightningcaused fire that burned 239,695 acres in

the Oregon Coast Range.

1962: Columbus Day Storm—the

strongest windstorm of the 20th

century on the west coast that blew

down more than 6.2 billion board feet of

timber in forests in western Oregon.

1964: The Wilderness Act—this act 

originally designated 9.1 million acres of

wilderness on national forest land across

the United States. Now nearly 100 million acres of wilderness, countrywide, is

Continues on page 4.

What is the

History

of Western Oregon Forests?
Logging in the Pacific Northwest created many changes in forest 

vegetation. Forest industry gained momentum in the late 1800s and into

the 1900s with railroads, steam and gas engines, new logging technology,

and demand created by the increasing and more prosperous population.

By the 1950s, the most productive western Oregon forests were being

managed to maximize timber production.When cutover sites were

replanted, Douglas-fir was usually the only species planted.

4

managed by the Forest Service, BLM,

and Fish and Wildlife Service. Oregon

currently has 40 wilderness areas, 28 

of these falling partially or wholly in

western Oregon and covering nearly 

1 million acres.

1970: The National Environmental

Policy Act—a law requiring analysis of

environmental and economic impacts 

of significant actions (such as timber

harvest) on federal lands.

1971: Oregon State Forest Practices

Act—the nation’s first forest practices

act setting minimum standards for state

and private forest lands for reforestation,

road construction and maintenance, timber harvesting, chemical application, and

slash disposal. Federal forest managers

agreed to meet or exceed these standards.

1973: Endangered Species Act—an act

requiring federal departments and agencies to conserve endangered and threatened species and their habitat.

1973: Oregon Land Conservation and

Development Act—a land use planning

law to limit further loss of Oregon’s

most productive forest and farm land.

1976: The National Forest Management

Act—requires the Forest Service to prepare management plans for each national

forest to provide for multiple use and 

sustained yield. Federal Lands Policy 

and Management Act in the same year

authorized BLM to inventory and manage its public land for similar purposes.

1993: Northwest Forest Plan—a plan

proposed by President Clinton to provide

for a sustainable forest environment and

economy in western Oregon, western

Washington, and northern California.

About 8 million federal acres are affected

by the plan in western Oregon.

Logging in western Oregon in the early 1900s. USDA FS Photo
Forest inventories by the Forest Service were authorized in 1928 by the McSweeney-McNary Forest Research

Act.The first inventory in western Oregon was undertaken in 1930. Inventories from that first one to the present

show a relatively stable amount of forest land (although many of the actual acres have changed from one status to

another in both directions).Timberland acres have decreased somewhat, although some of this has been offset by

the addition of abandoned Christmas tree plantations and natural reforestation of pasture land.

Today4

• Almost 90 percent of nonfederal and 95 percent of federal land in western Oregon remains in 

forest and agricultural uses.

• Oregon land use laws seek to preserve farm and forest lands while designating limited areas

for urban expansion.

• Between 1973 and 1982, 247,000 acres of forest and farm land were converted to low-density

residential and urban uses.

• Between 1982 and 1994, after land use plans were in place and with a slower economy, rate of

conversion declined from 27,000 to 6,000 acres per year.

• More than 80 percent of the shifts in land use in western Oregon from the 1970s to the 1990s

were from agriculture or wildland forest to low-density residential or urban areas.

• The most significant shifts from forest or farm uses to more developed uses occurred on private

land in the Willamette Valley.

4 Azuma, D.L.; Birch, K.R.; DelZotto, P. [and others]. 1999. Land use 

change on nonfederal land in western Oregon, 1973-1994. Salem, OR:

Oregon Departments of Forestry, Land Conservation and Development,

and Agriculture; U.S. Department of Agriculture, Forest Service. 55 p.

5
ALARGE PART OF WESTERN OREGON—

about 80 percent—is forested. Of western Oregon’s

19.2 million acres, 15.3 million are forested. Only the

larger river valleys (Willamette, Rogue, and Umpqua

Valleys), where most of the population of Oregon lives

and much of the state’s farming and industry occurs,

are sparsely forested.

The Oregon Coast Range unit comprises about 30 percent of western Oregon. It has the highest percentage of

forest land in the state. Because of the marine influence,

it has the warmest winters, coolest summers, and greatest

6

How Much of

Western Oregon Is Forest

and Where Is It?

Oregon Coast Range. Photo by Don Gedney

Forested land in

western Oregon

Percentage of forested 

land by county

Source: Forest Inventory and Analysis data, 1996 forest

inventory of western Oregon (unpublished), USDA Forest

Service, PNW Research Station, Portland, OR.

Source: Multiresolution Land Characterization Consortium (MRLC), U.S.

Geological Survey. Map produced by classification of Landsat 5 satellite

imagery (acquired 1992).

➢

N

➢

N
7

rainfall in Oregon. Many small- to medium-sized towns,

such as Tillamook, Newport, Coos Bay, and Bandon are

along the Pacific coast.

The Willamette Valley unit, nestled between the Coast

Range and the western slopes of the Cascade Range,

comprises about 18 percent of western Oregon, has the

lowest percentage of forest land, and the highest number

and concentration of people. Most of the land in the 

valley lies between 50 and 1,000 feet in elevation. Forests

are found primarily in the foothills of the Coast Range to the west and the Cascade Range to the east. Summers are

hot and dry, with periodic summer droughts.This unit includes the Portland, Salem, and Eugene metropolitan areas.

The Western Cascades unit, extending north to south on the western flank of the Cascade mountain range, makes

up 32 percent of western Oregon. It has the second highest percentage of forest land in the state.Wide ranges in 

elevation (near sea level to over 11,000 feet) and precipitation (50 to 150 inches) are typical of this unit.

The Klamath Mountains unit makes up about 20 percent of western Oregon. It is almost 80 percent forest land.

It is the most vegetatively diverse unit in western Oregon and one of the most diverse in the United States.The 

climate is mediterranean with generally mild, wet winters and warm, dry summers.Towns in this area include

Medford and Roseburg.

Ecological unit Forest landa Nonforest landa

Percent

Oregon Coast Range 94 6 

Willamette Valley 35 65 

Western Cascades 93 7 

Klamath Mountains 79 21 

a Based on plot data.

Willamette Valley. Photo by Don Gedney Western Cascades. Photo by Don Gedney

Klamath Mountains. Photo by Tom Iraci
MANY SPECIES OF TREES GROW IN WESTERN OREGON.

Forest inventories measure trees on each inventory plot and

record detailed information on live trees including species, age, diameter,

height, and damage by insects and disease.

Some trees, such as Douglas-fir, grow in a wide range of environmental

conditions and are found in every ecological unit in western Oregon.

Others have more specific growing requirements and may be found in

only one area, such as Port-Orford-cedar found only in the western 

portion of the Klamath Mountains unit. Fifty species of trees were tallied

in western Oregon inventories: 20 hardwood species and 30 conifer

species. Collections of species in an area make up a forest type, which,

in western Oregon, is named after the predominant species.

Oregon Coast Range 

Douglas-fir is the predominant species, and therefore forest type, in 

the Oregon Coast unit. Other common tree species in this area include

western hemlock, red alder, bigleaf maple, and western redcedar.

Lodgepole pine (or “shore pine”) and Sitka spruce occur along 

the coast.

8

What Trees 

Grow 

in Western Oregon?

Douglas-fir is the most common tree species in

western Oregon. Photo by Tom Iraci
Forest type Thousand acres Percent 

Douglas-fir 3,200.6 67.1 

Red alder 707.5 14.8 

Hemlocks (Tsuga spp.) 424.3 8.9 

Sitka spruce 139.6 2.9 

Bigleaf maple 48.0 1.0 

Oregon white oak 46.4 1.0 

Pines (Pinus spp.) 40.4 .8 

Pacific madrone 31.8 .7 

True firs (Abies spp.) 28.2 .6 

Western redcedar 22.6 .5 

Others 78.9 1.7 

Totals 4,768.3 100.0 

Western Cascades 

Douglas-fir is the predominant species and forest type in the Western Cascades unit. Other species such as western

hemlock, western redcedar, white fir, and grand fir are common at lower elevations, with Pacific silver fir, mountain

hemlock, lodgepole pine, and subalpine fir found at higher elevations.

Forest type Thousand acres Percent 

Douglas-fir 2,857.2 60.0 

Hemlocks (Tsuga spp.) 817.2 17.2 

True firs (Abies spp.) 713.5 15.0 

Pines (Pinus spp.) 109.2 2.3 

Red alder 79.1 1.7 

Western redcedar 47.5 1.0 

Bigleaf maple 30.0 .6 

Oregon white oak 14.3 .3 

Others 96.8 2.0 

Totals 4,764.8 100.0 

9

Sitka spruce. Photo by Tom Iraci

Mountain hemlock. Photo by Don Gedney
Willamette Valley 

Douglas-fir is the predominant species and forest type in the Willamette Valley. In addition to Douglas-fir, common

species include red alder, Oregon white oak, bigleaf maple, and western hemlock. Some unique native populations of

ponderosa pine (“valley pine”) and grand fir also can be found in the Willamette Valley, although many of these are

dwindling owing to urbanization, river channelization, and insect infestations.

Forest type Thousand acres Percent 

Douglas-fir 721.5 64.9 

Red alder 97.0 8.7 

Oregon white oak 94.9 8.5 

Bigleaf maple 94.8 8.5 

Western redcedar 20.9 1.9 

Western hemlock 19.5 1.8 

Oregon ash 14.7 1.3 

Black cottonwood 13.8 1.2 

Grand fir 9.8 0.9 

Others 24.4 2.2 

Totals 1,111.3 100.0 

10

Oregon white oak. Photo by Paul Dunham
11

Klamath Mountains 

The Klamath Mountains unit is the most vegetatively diverse in western Oregon—encompassing climatic,

geomorphic, and vegetative elements from California, the northwest coast of Oregon, and eastern Oregon.

Douglas-fir is the dominant species and forest type in this area. Other common species include dry-site hardwoods

such as tanoak, canyon live oak, Oregon white oak, Pacific madrone, golden chinkapin, California laurel, and

California black oak. Common conifers include western hemlock, incense cedar, white fir, western redcedar,

western white pine, Port-Orford-cedar, ponderosa pine, and sugar pine.

Forest type Thousand acres Percent 

Douglas-fir 1,981.8 28.5 

Tanoak 1,384.4 19.9 

Oaks (Quercus spp.) 1,113.4 16.0 

True firs (Abies spp.) 364.4 5.2 

Hemlocks (Tsuga spp.) 335.0 4.8 

Pacific madrone 321.2 4.6 

Incense cedar 295.1 4.2 

Pines (Pinus spp.) 281.2 4.0 

Golden chinkapin 251.2 3.6 

California laurel 180.1 2.6 

Western redcedar 123.2 1.8 

Port-Orford-cedar 86.3 1.2 

Red alder 56.3 0.8 

Bigleaf maple 41.0 0.6 

Others 143.0 2.1 

Totals 6,957.6 100.0 

Pacific madrone. Photo by Don Gedney
12

Who Owns

Western Oregon’s Forests?

THE FOREST SERVICE, BUREAU OF LAND MANAGEMENT AND OTHER FEDERAL AGENCIES

manage about 52 percent of forest land in western Oregon; industrial and nonindustrial private landowners

own about 41 percent; and the state of Oregon and other nonfederal public entities manage the remaining 7 percent.

Public forest land is owned by the public and managed by agencies such as the USDA Forest Service, USDI Bureau

of Land Management, Oregon Department of Forestry, counties, and municipalities. Most of the public forest land in

western Oregon is national forest—over 5.6 million acres of forest land is found on the Mount Hood, Rogue River,

Siskiyou, Siuslaw, Umpqua, and Willamette National Forests. Bureau of Land Management forest land includes 2.3

million acres primarily in the Coast Range and Klamath Mountains. State and other nonfederal public forest 

Land ownership

in western Oregon

Source: Ownership of western Oregon, Oregon Department of Forestry, Salem, OR.

➢

N
land, about 1 million acres, is also primarily in the Coast Range. Management of public forests is guided by management plans, and each plan typically allows for a multitude of uses across the landscape, from providing recreation to

harvesting timber to preserving wildlife to maintaining municipal watersheds. Plans are updated periodically with

public review.

A 1994 survey of private forest landowners showed that about 124,000 individuals or companies owned over 6.3

million acres in western Oregon.5 Private landowners own forest land for many different reasons.This makes it 

difficult to explain and predict how landowners will manage their forest resources.When private owners in western

Oregon were asked in 1994 why they owned forest land, most owned it because it was part of their residence or

because they bought it as an investment or for visual enjoyment. However, over 75 percent of the acres (owned 

by only 5 percent of owners) were used for timber production. Many of the private forest landowners, especially 

industrial owners, have management plans for their forests.

Primary benefit expected by private forest landowners in the next 10 years in western Oregon:

Benefit Number of owners No. acres Avg. acres per owner 

Land value increase 35,000 356,000 10.2 

Farm and domestic use 33,000 279,000 8.5 

Aesthetic enjoyment 30,000 490,000 16.3 

Other 8,000 123,000 15.4 

Income from timber 6,000 4,873,000 812.2 

Recreation 2,000 110,000 55.0 

Firewood 1,000 27,000 27.0

Sources: Birch,T.W. 1997. Private forest-land owners of the western United States, 1994. Resour. Bull. NE-137.

Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 249 p.

Butler 2001 (see footnote 5).

5 Butler, B.J. 2001. Extraction of data for western Oregon from 1994 survey 

database. National Woodland Owner Survey Coordinator. Newtown Square,

PA: U.S. Department of Agriculture, Forest Service, Northeastern Research 

Station.

13

National Forests in western Oregon manage over 5.6 million acres of

forest land. Photo by Don Gedney

Forestry companies own over 6.3 million acres in western Oregon.

Photo by Don Gedney
14

FOREST AGE DEPENDS ON THE TIME SINCE THE LAST 

harvest; the frequency, extent, and severity of disturbances such 

as forest fires or insect outbreaks; and, if left undisturbed, the lifespan of 

different species. Some tree species, such as cottonwood with average lifespans of 60 to 90 years, are relatively shortlived. Others, such as Douglas-fir

and Sitka spruce, can live for several hundred years.

Disturbances that cause mortality (fire, disease, insect attack, wind storms,

flooding, etc.) result in mosaics of tree ages as regeneration fills in the gaps

created by dead trees.The pattern of mortality, and thus ages, can differ

from large continuous areas to small patches to single trees scattered

throughout the forest.

Recently planted Douglas-fir seedling. Photo by

Tom Iraci

Several age cohorts of Douglas-fir in the Oregon Coast Range. Photo by Don Gedney

Older Douglas-fir. Photo by Tom Iraci

How Old Are 

Trees

in Western Oregon?
There are many areas in western Oregon where trees have never been harvested—mainly on public lands in reserved

areas such as wildernesses in national forests and at higher elevations. Most of the reserved lands are in the Western

Cascades and Klamath Mountains units and are federally owned.About 17 percent of the acres in these reserve areas

have forests older than 200 years.

The majority (about 78 percent) of western Oregon’s forests are under 120 years old. National forest lands have

more acres with older trees (over 60 years old) than other lands where most acres have trees under 60 years old.

Distribution of tree ages varies by ecological unit and most likely is related mainly to past disturbances (primarily

large fires), ownership, and management activities:

• The Coast Range and Willamette Valley units have relatively younger forests, with the majority of acres between 

1 and 60 years old. Less than one percent of the acres have forests greater than 120 years old.

• The Western Cascades unit has a fairly even number of acres in each age class. It has the highest number and 

percentage of acres with forests over 200 years old—about 850,000 acres and 18 percent, respectively.

• The Klamath Mountains unit has the majority of acres (62 percent) with forests between 20 and 120 years old.

About 7 percent of the acres have forests greater than 200 years old.

15
TIMBER REMAINS AN ESSENTIAL 

part of western Oregon’s economy.

Many products such as paper, lumber, particle

board, firewood, and oak barrels are produced 

from the timber in western Oregon’s forests.The

forests of western Oregon have about 78 billion

cubic feet of timber (1 cubic foot = 1 foot high 

by 1 foot wide by 1 foot deep).This volume

would classify western Oregon as one of the top

timber regions of the country.

The ownership of this timber is a key factor in

determining the availability of the timber for commercial use.About 71 percent of this volume is in federal ownership, mainly BLM and Forest Service, and is not necessarily available for production of forest products.The average

volume produced from federal timberlands between 1995 and 1997 is about 30 percent of what the average production was in the decade of the 1980s. Federal lands have reduced production for various reasons including riparian

and wildlife reserves and withdrawal of limited access areas. Some state lands also may be withdrawn in the near

future depending on present studies.

The volume differences between federal and nonfederal lands are most pronounced in the western Cascades and

Klamath Mountains where federal lands have 90 and 76 percent of the volume, respectively. In the Willamette Valley,

nonfederal owners own about 88 percent of the volume.

16

35

30

25

20

15

10

5

0

Billion cubic feet

Willamette

Valley

Oregon

Coast

Range

Western

Cascades

Klamath

Mountains

Federal

Nonfederal

Timber Volume on Forest Land

0.38

3.29

11.34

13.32

29.3

3.65

12.6

4.23

Western Oregon’s forests produced over 9 billion cubic feet of wood from

1985 to 1997. Photo by Tom Iraci

What Is the

Volume of Wood

in Western Oregon?
BETWEEN THE 1980s AND 1990s,TREES ON STATE AND PRIVATE TIMBERLANDS IN WESTERN

Oregon grew faster than they died or were cut. Current change data was not available for federal timberlands.

“Growth” is the annual average growth of live trees that can be measured for volume.“Removal” is the annual 

average volume removed by harvesting, silvicultural activities (such as thinning), and land clearing.“Mortality”

(death) is the annual average volume of trees that died of natural causes. Natural causes include competition, insect

attack, disease, fire, drought, or other environmental factors.

Comparing tree growth to mortality plus removals from the 1980s to the 1990s illustrates one aspect of forest 

sustainability.The ratio of annual growth to mortality plus removals exceeded 1.0 for all ecological units, indicating

that the volume of wood is increasing on nonfederal timberlands in western Oregon.The ratio was highest in the

Western Cascades and Klamath Mountains units and lowest in the Willamette Valley and Coast Range units.

17

How Fast Are 

Trees Growing,Dying,

and Being Removed

in Western Oregon?

Growth of forests is 

estimated from tree

measurements. Photo 

by Tom Iraci
18

Mortality caused by western spruce budworm in the late 1980s. Photo by Tom Iraci 

Harvesting in the Oregon Coast Range. Photo by 

Don Gedney 
DEAD WOOD IS AN ESSENTIAL PART OF THE FOREST. When trees die from natural causes, they 

often remain standing for a period of time—these standing dead trees are called “snags.” All dead trees 

eventually fall to the ground, becoming “down wood.”When trees are harvested, portions of the tree may be left

behind—branches or unusable sections of the trunk. Dead wood, whether standing or down, plays key roles in forest

ecosystems: it stores carbon; releases nutrients as it decays; provides substrate, habitat, and food for a wide array of

other plants and animals; holds moisture; and serves as fuel for wildfire.

In western Oregon forests, the amount of dead wood varies tremendously across space and time. It is affected by 

forest age and type, site productivity, ownership (and therefore management activities), geographic and topographic

location, and by the amount of insect, disease, and other mortality-causing events including fires and windstorms.

19

How Much 

Dead Wood

Is in Western Oregon Forests?

Snags and down woody debris. Photo by Tom Iraci.
20

Down woody debris includes decaying logs. Photo by Don Gedney