Opportunities for Making

Wood Products from

Small Diameter Trees

in Colorado

Dennis L. Lynch

Kurt H. Mackes

United States

Department

of Agriculture

Forest Service

Rocky Mountain

Research Station

Research Paper

RMRS-RP-37

September 2002

Sponsors

Colorado State Forest Service

Colorado State University

USDA Forest Service: State and Private Forestry,

Rocky Mountain Region,

and Rocky Mountain Research Station
Lynch, Dennis L.; Mackes, Kurt H. 2002. Opportunities for making wood products from small

diameter trees in Colorado. Res. Pap. RMRS-RP-37. Fort Collins, CO: U.S. Department of

Agriculture, Forest Service, Rocky Mountain Research Station. 11 p.

Abstract—Colorado’s forests are at risk to forest health problems and catastrophic fire. Forest areas at high

risk to catastrophic fire, commonly referred to as Red Zones, contain 2.4 million acres in the Colorado Front

Range and 6.3 million acres Statewide. The increasing frequency, size, and intensity of recent forest fires

have prompted large appropriations of Federal funds to reduce fire risk and improve fire protection. Experimental ecological restoration studies using thinning and prescribed fire have been conducted at several

locations across the State during the past 5 years to determine if high-risk areas could be treated to improve

forest health and reduce the potential for catastrophic fires. These studies established that 80 to 96 percent

of the trees removed to improve ecological conditions were between 5 and 11.9 inches in diameter. Some

trees 12 inches and larger in diameter had to be removed to properly apply ecological prescriptions and

typically comprised 4 to 18 percent of the trees removed. The projects studied had profit margins of 1 percent

(Pines Partnership), 6 percent (Mixed Conifer Project), a loss of $78,000 (Chessman Reservoir-Trumbull

Project), and required subsidies of $779 per acre (Fox Run) and $679 per acre (Air Force Academy).

A search for opportunities to use small diameter trees from these projects was conducted as part of an

effort to improve the financial feasibility of forest restoration. A previous study, “Wood Use in Colorado at the

Turn of the Century” (Lynch and Mackes 2001), describes in detail the various types and quantities of wood

products used in the State and identifies where products came from. Using this study, the authors identified

potential products that might be manufactured from small diameter trees removed in restoration thinnings.

The potential opportunities for using wood are listed in two categories: (1) existing products, processes,

and technology, and (2) new products, processes, and technology. Products are arranged within each category in order of increasing complexity of processing and technology. Estimates of the potential retail market

value for each product are presented. Examples of existing product opportunities include Christmas trees,

mine props, firewood, posts and poles, rough sawn lumber and timbers, and oriented strandboard. Examples of new products and processes include structural roundwood, biomass energy, and wood pulp. The

report concludes that future restoration programs must be designed to provide a consistent supply of raw

material to processors. It also recognizes that there is no single product that will utilize all small diameter

trees from Red Zone areas. Instead, a stable, diverse wood industry appears to be the most desirable future.

Keywords: small diameter trees, wood products, forest restoration

The Authors

Dr. Dennis L. Lynch is a Professor Emeritus in the Department of Forest Sciences, College of Natural

Resources, Colorado State University. He served as a professor in the Department for 25 years. During the

past 7 years he has been involved in forest restoration and wood utilization research in Colorado through a

partnership with the Colorado State Forest Service, the USDA Forest Service Rocky Mountain Region, and

the Department. He also currently serves as Senior Technical Advisor to the Interior West Center for the

Innovative Use of Small Diameter Trees at Colorado State University.

Dr. Kurt H. Mackes is an Assistant Professor in the Department of Forest Sciences. He is principal investigator on a wide variety of small diameter wood research projects. Currently, he is the key contact for wood

science research and information relating to this report.

Both authors may be contacted at:

Department of Forest Sciences

Colorado State University

Fort Collins, CO 80523-1470
Acknowledgments

We wish to acknowledge our reviewers for their contributions to this paper.

They include:

Chris Jennings- Research Associate, Department of Forest Sciences, Colorado State University,

Fort Collins, CO.

Chuck Dennis, Colorado State Forest Service and Denver Water Board Forester, Broomfield, CO.

Dave Hessel, South Platte Forest and Watershed Restoration Project, Colorado State Forest Service, Broomfield, CO.

Phil Schwolert, Forest Management Division, Colorado State Forest Service, Colorado State University, Fort Collins, CO.

Bill Wilcox, Emeritus Assistant State Forester, Colorado State Forest Service, Colorado State University, Fort Collins, CO.

Linda Joyce, Rocky Mountain Research Station, Fort Collins, CO.
Contents

Introduction .................................................................................................................................... 1

Forest Restoration Studies .............................................................................................................. 1

Wood Product Studies .................................................................................................................... 3

Potential Opportunities in Existing Markets .................................................................................. 3

Christmas Trees .......................................................................................................................... 3

 Mine Props.................................................................................................................................. 4

Firewood ..................................................................................................................................... 4

Posts and Poles ........................................................................................................................... 4

House Logs ................................................................................................................................. 4

Utility Poles or Pilings................................................................................................................ 5

Biomass Chips ............................................................................................................................ 5

Rough Sawn Lumber and Timbers ............................................................................................. 6

Sawn, Kiln Dried, Planed, and/or Graded Lumber .................................................................... 6

Shavings and Sawdust for Animal Bedding ............................................................................... 7

Oriented Strandboard (OSB) ...................................................................................................... 7

Potential Opportunities for New Products, Processing, and Technology ....................................... 9

Roundwood for Structural Applications ..................................................................................... 9

Wood Pellets ............................................................................................................................... 9

Biomass Energy .......................................................................................................................... 9

Composite Products .................................................................................................................. 10

Cement-Wood Products ............................................................................................................ 10

Pine Excelsior ........................................................................................................................... 10

Wood Pulp ................................................................................................................................ 10

Other Opportunities .................................................................................................................. 11

Conclusion .................................................................................................................................... 11

References .................................................................................................................................... 11

iii
USDA For. Serv. Res. Pap. RMRS-RP-37. 2002. 1

Introduction

Natural resource management agencies recognize

that Colorado forests have serious forest health problems and significant potential for catastrophic forest

fires. Forest areas at high risk to fire, commonly referred to as Red Zones, have been identified for the

Front Range as well as Statewide. The Front Range

Red Zone area is estimated to contain 2.4 million acres

that must be treated to reduce the risk of catastrophic

fire (USFS 1996). There are 6.3 million high-risk acres

Statewide (CSFS 1998a), and estimates of high and

moderate risk areas total 17.3 million acres. Census

data from 1990 indicate 750,000 people and 300,000

dwellings are present in high-risk areas, figures that

will undoubtedly be revised upward substantially when

2000 census data are available.

Catastrophic fire events such as the 1996 Buffalo

Creek fire, the Hi Meadows, Bobcat Gulch, and Mesa

Verde fires in 2000 focused attention on the need for

restoration programs to reduce fire risk. Thinning and

removing trees from critical forest areas and restoring

normal ecological processes, such as low intensity fires,

can mitigate high-risk areas. Following the 2000 fire

season, appropriations of Federal funds increased dramatically for forest and watershed restoration as well

as for increased fire protection. As these programs are

implemented, the need to effectively dispose of small

diameter trees and forest fuels will increase. The purpose of this paper is to discuss opportunities to utilize

wood from small diameter trees.

Forest Restoration Studies

In experimental studies conducted between 1996

and 2002 (Lynch and others 1998, Lynch and Jones

1998, Lynch and others 2000, Lynch 2000) trees were

removed from several forest areas in Colorado to

achieve ecological restoration objectives. These objectives were established to improve forest health and

reduce the incidence of catastrophic fire by ecologists.

In particular, objectives focused on making changes

beneficial to forest structure, reducing fuel loading,

improving plant diversity, reproducing trees, and reintroducing natural fire regimes. From these experimental studies, findings indicate that accomplishing forest

restoration objectives requires mechanical removal of

undesirable smaller trees, retention of larger trees and

snags, and use of prescribed fire. This is essentially

the opposite of traditional logging where large trees

are removed and small trees are left. Results of these

studies in relation to small diameter tree removals are

summarized in table 1.

Material in the 3 to 4.9 inch diameter class was usually not merchantable. Trees in this size class were cut

and left on the site for subsequent prescribed burning

as specified in the ecological restoration prescription.

The white fir-aspen unit at Gordon Creek was so

densely populated with trees in this size class that a

specific effort was made to count the stems cut to better describe costs. Trees lees than 3 inches in diameter

were often consumed in the prescribed fire that followed thinning. In the Air Force Academy Project

smaller trees were chipped, removed from the site, and

used for energy fuel tests.

From the table, a definition of what is meant by small

diameter trees becomes clear. In all but two of the

forest restoration units 80 to 96 percent of the trees

removed were below 12 inches in diameter. Trees that

were 12 inches and larger amounted to 4 to 18 percent

of the trees removed. The exceptions are the Joyce

unit (100 acres) of the Pines Partnership Project and

the small sample unit in the Air Force Academy Project

(10.7 acres). In these two cases, the forest being thinned

consisted of more large trees. The same ecological

Opportunities for Making Wood Products

from Small Diameter Trees in Colorado

Dennis L. Lynch

Kurt H. Mackes
2 USDA For. Serv. Res. Pap. RMRS-RP-37. 2002.

prescription used in units 1, 4, 5B, and 5E of the Pines

Partnership Project was also applied in the Joyce unit.

In the Air Force Academy study a separate ecological

prescription was written for the unit because the forest

area was distinctly different from the other units

thinned. The results from these units demonstrate

that when ecological restoration prescriptions are

applied to forest areas needing fuel reduction treatment, there usually will be some areas where larger

trees must be removed. However, as the above data

show, most trees removed will be less than 12 inches

diameter at breast height. It is important to note

that if 12 inch and larger trees had not been removed

from all units, ecological restoration would have

been incomplete and improperly done. Therefore,

restoration must focus on the ecological prescription and not on tree diameter.

Removing trees in restoration projects is expensive.

The general rule is: the smaller the trees, the higher

the costs of removal. This is evidenced by the financial results of these studies. The Pines Partnership

Project netted less than 1 percent profit before taxes,

the Gordon Creek project netted approximately 5 percent profit before taxes, the Fox Run Project required

payment of $779 per acre to accomplish the work, the

Cheesman-Trumbull Project resulted in a $78,000 loss

Pines Partenership Project - San Juan National Forest (Dolores, Colorado) 

Unit Acres Species 3 to 4.9" 5 to 7.9" 8 to 11.9" 12" + Tons/Acre

Unit 1 125 Ponderosa No Data 50.1% 39.2% 10.7% 29.6

Unit 4 95 Ponderosa No Data 48.4% 41.1% 10.5% 33.3

Unit 5B 108 Ponderosa No Data 40.9% 51.8% 7.3% 35

Unit 5E 65 Ponderosa No Data 44.3% 51.4% 4.2% 23.5

Joyce 100 Ponderosa No Data 22.0% 26.0% 52.0% 21.7

Gordon Creek Project - San Juan National Forest (Pagosa Springs, Colorado)

Species 3 to 4.9" 5 to 7.9" 8 to 11.9" 12" + Tons/Acre

White fir 49.1% 15.1% 17.5% 18.3% 36.1

Aspen -- 30.2% 69.8% -- 10.7

Fox Run Project - Black Forest (Colorado Springs, Colorado)

Acres Species

24 Ponderosa

* Estimated, not weighed

Cheesman Resevoir - Trumbull Project (Deckers, Colorado)

Unit Acres Species 3 to 4.9" 5 to 7.9" 8 to 11.9" 12" + Tons/Acre

Cheesman 83 Ponderosa No Data 56.5% 31.8% 11.7% 14.5

Trumbull #5 42 Ponderosa No Data 57.1% 32.9% 10.0% 9.9

Trumbull #6 33 Ponderosa No Data 62.0% 28.4% 9.6% 14.8

Air Force Academy - near Colorado Springs, Colorado

 A total 138 acres treated - following data from samples

Unit Acres Species 3 to 4.9" 5 to 7.9" 8 to 11.9" 12" + Tons/Acre

Sample 1 10.7 Ponderosa 15.5% 17.8% 29.0% 37.8% **

Sample 2 11.2 Ponderosa 7.7% 38.6% 44.3% 9.3% **

Sample 3 2.2 Ponderosa 23.6% 49.7% 22.7% 4.0% **

** Tons per Acre data is still being collected at the time of writing this report

Percent Removal by Diameter Class

Percent Removal by Diameter Class

Avg. Diameter

7.9

Total Cords

162

Tons/Acre

Percent Removal by Diameter Class

Percent Removal by Diameter Class

75 Acre Unit

18-20*

Table 1—Colorado foresst restoration projects with trees emoved from site.
USDA For. Serv. Res. Pap. RMRS-RP-37. 2002. 3

to the contractor, and the Air Force Academy Project

required payment of $679 per acre to the contractor.

Wood Product Studies

Wood products manufactured from the trees removed in forest restoration studies included oriented

strandboard, rough sawn lumber and timbers, studs

(2x4’s), paneling, posts and poles, excelsior, pulpwood,

and firewood. Wood chips and short logs were also

used in research projects. Because the financial results of restoration projects revealed low profit or

losses, studies were initiated to determine how to reduce costs and improve revenue from wood product

opportunities.

The authors are conducting studies to investigate

wood products that might potentially be manufactured

from small diameter trees. The basis for these studies

was the comprehensive survey, “Wood Use in Colorado at the Turn of this Century” (Lynch and Mackes

2001). This survey lists the various types of wood products used in Colorado, quantifies the amount of wood

used, and identifies where the wood comes from. Colorado is considered a superb market for wood products

of all types, and its citizens use tremendous quantities

of wood in a wide variety of applications. However,

nearly 90 to 100 percent of the wood used comes from

other States and countries. This presents Colorado with

an opportunity to utilize wood from its own forests to

meet some of this demand while improving ecological

conditions in Colorado forests.

Wood from small diameter trees, particularly ponderosa pine from the Colorado Front Range, has a number of material problems. These trees have numerous

limbs, and as a result the wood has a high frequency of

knots, often large. Trees have often grown in crowded

conditions under stress. As a result, growth rings are

dense and the wood may be quite hard. In addition,

growth stresses create compression wood, often referred to as reaction wood, in these trees. When lumber is cut from the tree, it does not dry uniformly, and

stresses within the board result in warping. The wood

also may split, crack, or check during drying, further

degrading the quality of lumber and timbers. These

problems are not easily overcome and can result in

considerable loss and waste. The lumber may not even

be satisfactory for low quality uses such as pallets.

Other tree species such as white fir and Douglas-fir

have their own unusual set of material problems. Therefore, caution should be exercised in predicting that

small trees will result in a windfall of wood for higher

value uses. Considerable small diameter material

testing and product development will be necessary to

create satisfactory products for use.

A survey conducted by the Colorado State Forest

Service (CSFS 1998b) shows that wood processing

plants in Colorado are primarily small businesses,

mostly family owned and operated. There have been

exceptions, such as Louisiana-Pacific Corporation

(their oriented strand board plant recently closed) and

Koppers Corporation. While Koppers is part of a larger

corporation, it actually has a rather small operation in

Colorado and is mainly involved in treating wood to

improve its durability. To stay viable, small businesses

need a constant raw material supply at a reasonable

price, assistance with research and development, and

assistance with marketing. Unfortunately, consistent

supplies of wood at reasonable prices have not been

available in the past. Over the years, the wood supply

from public lands has been steadily declining and has

also been inconsistent. Pricing has not always been

realistic considering the low quality of the trees and

the high costs of removal. As a result, many firms

have gone out of business or have been unable to invest in updated technology. Therefore, the State has

been gradually losing industrial potential to utilize

small diameter trees from the forests. Also, a vigorous

program of forest thinning to solve health and fire problems may be confronted by the limited ability of existing firms to utilize trees that need to be removed from

Red Zone areas.

Potential Opportunities in Existing

Markets

In this section, suggestions of possible volumes,

values, and opportunities to use small diameter trees

in existing markets are presented based on previous

study of wood use in Colorado (Lynch and Mackes

2001). This list starts with opportunities to utilize wood

in simple products using existing facilities and technology. It then moves to new product opportunities

that require increasingly complex processing and new

technology investments.

Christmas Trees

Douglas-fir, white fir, subalpine fir, and lodgepole pine are the most desirable Christmas trees in

Colorado forests. To utilize them, the trees only need

to be cut and marketed. No further processing is

needed for fresh, wild trees. Many forest areas with

potential for catastrophic fires have these species

present in the understory. These trees create a fuel
4 USDA For. Serv. Res. Pap. RMRS-RP-37. 2002.

ladder for fires to move up into the crowns of larger

trees. In other areas, these species create dense

stands with closed canopies that are prone to devastating crown fires.

The potential exists to meet virtually all of

Colorado’s demand (495,000 trees in 1998) for Christmas trees and improve forest health at the same time.

However, not all Christmas trees in the forests are “perfect.” Such trees have not been tended or sheared as

occurs on commercial Christmas tree farms. Therefore, efforts must be made to assist small businesses

with marketing and to increase public awareness that

using such “imperfect,” but “organic,” trees is actually environmentally beneficial. This market had an

estimated total retail value of $11.6 million in 1999.

 Mine Props

Mine props are quite possibly the simplest roundwood product. A small log that is 6 inches in diameter

on the small end, from 5 to 11 feet in length, relatively

straight, limbed, unpeeled, and dry can make a mine

prop. Lodgepole pine, ponderosa pine, Douglas-fir,

and Englemann spruce are preferred. Aspen and true

firs are used but are least preferred. Conservatively,

an additional 75,000 mine props could be thinned from

Colorado forests each year to improve forest health

and reduce intense fires. For example, if every tree in

a forest area were just the right size for a mine prop, an

estimated 1,500 acres could be thinned each year.

Unfortunately, trees in a forest are seldom that uniform in size and shape. Thus, mine props are but one

of several products that might be realized from a thinning program. The principal barriers to the use of mine

props from Colorado forests are inappropriate stumpage rates charged by agencies, unrealistic contract requirements, and the lack of a consistent thinning program to date. This market had an estimated total retail

value of $710,000 in 1999.

Firewood

Firewood production requires cutting a tree into segments, splitting the segments, and allowing these to

dry. Virtually every tree species in Colorado is acceptable for firewood use. However, Engelmann spruce

may be the least desirable because of its tendency to

pop and throw sparks while burning, although among

some campers this natural fireworks display may be

considered entertaining. The firewood market is currently fragmented geographically, and communication

among buyers and sellers is not well developed.

Currently, some people have firewood to sell but no

buyers, while others want to buy firewood but can’t

find a seller. This could be resolved by establishing a

type of “virtual firewood sort yard” on an Internet Web

site where commercial buyers and sellers could list

firewood supply and demand. It could also provide a

list of firewood vendors for private individuals to contact. There is a potential to provide up to 3,200 cords

of small bundle firewood annually from Colorado that

is now imported from other States and countries. That

potential retail market value of this firewood is approximately $1.2 million at current market prices. In addition, bulk firewood could also be provided in place of

imported wood. When fossil fuel prices rise for home

heating, it is anticipated that the firewood market will

again become attractive to many homeowners. Such

demand may also improve opportunities to reduce

wood residues from manufacturing or municipal tree

wastes. Information is not available to estimate the

market value of bulk firewood that could replace imported firewood or satisfy current unmet demand.

Posts and Poles

Fence posts need to be cut to length, peeled, dried,

and treated with chemicals to resist decay. Rocky

Mountain juniper has been used for native fence posts

without peeling or treating for more than 100 years.

The preferred species for manufactured posts and poles

are lodgepole pine (90 percent of the market), ponderosa pine, and Douglas-fir. Aspen is sometimes used

in decorative applications. It takes a fairly uniform,

straight log with minimal taper to make an acceptable

post or pole. Over 300,000 posts where used in 1999

for agricultural fencing, and approximately 60 percent

of these came from out of state. Some smaller diameter material can be sorted for other roundwood uses.

Markets exist for stair and deck banisters and balustrades, latillas, tepee poles, decorative posts, tourist and

gift items, and rustic furniture. These markets are often localized and limited in size. Research and marketing assistance could improve opportunities for the

use of less desirable species in the post and pole market. An estimated 100,000 posts that are imported annually could be replaced by posts processed in State

with a retail market value of approximately $600,000

based on current market prices.

House Logs

House logs are cut to length, peeled, and notched

before use. Custom log homebuilders prefer long, large

logs. Natural house logs need to be 10 inches or more

in diameter, straight, and fairly uniform in size with

little taper. In some cases logs may also be milled to

achieve uniformity or a desired shape. However,
USDA For. Serv. Res. Pap. RMRS-RP-37. 2002. 5

several building techniques are used to accommodate

variation in log shape and length.

Approximately 4.05 million lineal feet of logs were

used in Colorado log homes in 1998. Most logs were

imported from out of State, and many came in kits or

in previously manufactured log home packages. For

example, log home packages are currently imported

from as far away as Finland.

Engelmann spruce and lodgepole pine are the most

preferred and commonly used Colorado tree species

for log homes. However, ponderosa pine and Douglas-fir are also used by some builders.

Small diameter material has been used in the past to

construct log dwellings in Colorado. Such material,

however, may have defects that render it unsuitable

for house logs. Machining or milling small diameter

logs can produce attractive, uniform-sized material for

log home construction. In addition, there are forest areas where removals of larger house logs could benefit

forests by increasing defensible space or improving

forest health, particularly in areas infested with bark

beetles. A thinning program that is flexible enough to

take advantage of such areas could also improve the

overall economic outlook for forest restoration by including higher value house log material to offset costs

associated with low value small material. The 1998

retail value of the house log market in Colorado was

$37.5 million.

Utility Poles or Pilings

Utility poles and pilings must be cut to length,

peeled, dried, and treated with chemicals to resist

decay. Trees must be straight, fairly uniform in size

with a minimum of taper, and meet length requirements. In Colorado, lodgepole pine is the preferred

species. The necessary facilities to treat such long

logs exist only in Denver. In addition, logs that are

acceptable for utility poles or pilings are also of the

size and length that make them attractive for higher

value house logs.

Since all utility poles are imported, the size of the

potential market for Colorado is really dependent on

the supply offered. The total retail value of the Colorado market was $16.9 million in 1998.

Biomass Chips

The tops and limbs, and unmerchantable small trees

resulting from thinning, must be disposed of in some

manner. One historic method of disposal of this material, commonly referred to as slash, has been to conduct a prescribed burn. In many cases, however, the

existing amount of fuels in the forest plus the addition

of slash may create prescribed fire conditions that could

damage a forest severely. Therefore, other methods

such as chipping, shredding, or grinding may be needed

to reduce fuel loading. Depending on chip size and

shape, several potential uses are:

Landscape Mulch — All tree species and even

some shrub species can be used for landscape mulch.

To create this product, the treetops and limbs are

chipped, shredded, or ground mechanically into particle sizes and shapes that fit desired landscaping uses.

Usually long strip-like chips that will intertwine and

resist blowing by the wind are most popular. A number

of small businesses within Colorado currently convert

municipal tree wastes into landscape mulch. However,

an estimated 80,000 cubic yards of cedar and redwood

landscape mulch are still imported each year with an

estimated retail value of $2.8 million at current market

prices. Much of this imported mulch could be replaced

with urban tree waste material from Colorado if market preferences for cedar and redwood mulch could be

overcome and if current landfill tipping fees were to

become more realistic. Landfill tipping fees are often

too low, resulting in burial of potential mulch material

rather than utilization.

Mulching is also a particularly good way to dispose

of limbs and small, deformed trees from forest

thinnings. However, mulch is a relatively low value

product and very cost sensitive to harvesting, loading,

and hauling material from the forest. Therefore, in most

cases, small material that is only suitable for mulch

must be regarded as a liability and will require subsidies to remove it.

Compost — Nitrogenous wastes are often difficult

to dispose of and may threaten water supplies. However, when combined with carbon, microorganisms can

break down such wastes into a useful soil amendment

and water-conserving material known as compost.

Currently, there is strong demand for compost in agricultural applications as well as residential lawn and

garden uses in Colorado. Several projects using wood

chips and various nitrogenous wastes for composting

have been conducted in Colorado. Where the right combinations of wood residues and nitrogen sources are

available, composting is an effective and profitable way

to use wood residues. At this time, it is not possible to

estimate the opportunity for using small diameter material from the forest in composting. However,

composting is growing for a number of reasons and

has the potential to be a significant user of wood biomass. A new study is pending that will explore a new

dimension of composting and identify key costs as well

as the type of chips that are most suitable for use.
6 USDA For. Serv. Res. Pap. RMRS-RP-37. 2002.

Rough Sawn Lumber and Timbers

All Colorado tree species are used for rough sawn

lumber, although some species have characteristics and

properties that make them more desirable. The tree

must be cut into even length logs (usually 8, 10, 12,

14, and 16 feet) plus a 3 to 6 inch trim allowance and

then sawn into boards and/or timbers. Debarking the

tree before sawing may improve the potential range of

products from the tree and reduces wear on saw blades.

In Colorado, rough lumber and timbers are typically

air-dried. Small diameter trees may contain compression or reaction wood that can cause twist, sweep,

crook, cupping, and splitting of lumber and timbers.

Care must be taken in sawing and drying to reduce

such losses. Potential products and market volumes

used are presented in figure 1. The retail values of

each of the products shown in the figure can be obtained from “Wood Use in Colorado at the Turn of the

Century” (Lynch and Mackes 2001). However, for purposes of this report, the total retail value of the above

products was estimated to be $53 million in 2000.

Residues from the processing of the rough lumber and

timber products may be used for:

• Decorative landscaping bark from ponderosa pine

or Douglas-fir (ring debarking is preferred to produce desirable bark chunks).

• Large animal bedding (dry peelings and sawdust).

• Small animal bedding (dry sawdust).

• Compost (green sawdust added to a nitrogen

source along with water).

• Slabs for cabin siding, fencing, firewood, or, if

peeled, made into shavings for animal bedding.

Sawn, Kiln Dried, Planed, and/or Graded

Lumber

Most Colorado tree species can be used for sawn,

kiln dried, planed and/or graded lumber to some degree, but true firs, blue spruce, and aspen are less desirable for structural purposes. As noted in the rough

sawing discussion, small diameter trees may contain

relatively high frequencies of knots, reaction wood, and

other defects that may reduce structural properties resulting in losses or down grading. A mill with kilns,

planers, and grading operations is located at Montrose,

CO. Other mills that air-dry and plane lumber are located in several places across the State. However,few

if any of these mills have grading stamps. Potential

products and volumes are presented in figure 2. While

it is unlikely that the harvest from Colorado forests

could meet this level of demand, the total retail market

value for the above products is estimated at $591 million in 2000. However, any dried, planed, and graded

lumber from Colorado could be used to offset imports.

In addition, dried and planed lumber may be used in

50

11

3.4 2.4 2.1 1.1 0.272 0.08

38.6

8.2

0

10

20

30

40

50

60

Pallet lumber

Fencing lumber

Landscape timbers 

(require treating)Railroad ties 

(require treating) 

Guardrail posts 

(require treating) Cribbing for 

mines Mine 

timbers

Dunnage for 

truck 

transportation

Mine for 

capboards 

and wedges

Signposts 

(may require 

treating)

Volume (million board-feet)

Figure 1—Annual Colorado consumption (2000) of rough sawn lumber and

timber products.
USDA For. Serv. Res. Pap. RMRS-RP-37. 2002. 7

softwood flooring, molding, paneling, finger- jointed

products, and edge-glued panels. Some mills also create planed log siding and specialty products. No volume or value estimates for these products are currently

available.

Shavings and Sawdust for

Animal Bedding

Dry shavings and sawdust from nearly all tree species are used in these markets. However, only aspen is

currently used for laboratory animal bedding. Studies

done by Mackes and others (2000) suggest that white

fir shavings may also be desirable for laboratory animal bedding. Figure 3 shows the animal bedding products and volumes currently consumed annually in Colorado. The total retail value of these products was estimated to be $10.1 million in 1999.

Oriented Strandboard (OSB)

Aspen, true firs, lodgepole pine, and ponderosa pine

are used to make oriented strandboard. OSB is an important structural panel and preferred in many applications over plywood. In this process, trees are cut into

logs that are peeled, processed to the appropriate length

and waferized. The wafers are coated with a resin and

oriented directionally into a thick mat. Heat and pressure are applied to compress the mat into a board with

a predetermined thickness. Boards are trimmed to a 4

foot width by an 8 foot length. This is an excellent

way to utilize small diameter trees of any shape or condition. An OSB plant in Olathe, CO, that was operated by Louisiana-Pacific Corporation recently closed

due to lack of wood supply and a depressed market.

This plant had the capacity to meet 21 percent of the

market if all of its production had remained within the

State. However, the location of this plant made utilization of small diameter material from the Front

Range more expensive. If an OSB plant were constructed at a central location along the Front Range,

it could provide an excellent outlet for trees from

thinning projects ongoing in the region. The market in Colorado appears to be easily able to support

one to two plants. Marketing efforts encouraging

construction firms to buy Colorado wood products

would help. Current uses of OSB are outlined in

figure 4. Annual consumption volume estimates

given in figure 4 are on a 3/8-inch basis, and the

retail value of these products was estimated at $231.5

million in 2000.

228

35.8

1.1

72.2

9.75

0

100

200

300

400

500

600

Residential

framing lumber

Residential remodeling

lumber

Decking

(require treating)

Commercial/

industrial lumber

Mobile home

lumber Highway lumber

602.7

Volume (million board-feet)

Figure 2—Annual Colorado consumption (2000) of sawn, kiln dried, planed, and/

or graded lumber products.
8 USDA For. Serv. Res. Pap. RMRS-RP-37. 2002.

123

2

802

282

75

0

100

200

300

400

500

600

700

800

Horse bedding

Small mammal

bedding

Dairy cattle

bedding Turkey &

chicken bedding

Laboratory

animal bedding

Volume (thousand cubic yards)

Figure 3—Annual Colorado consumption (2000)

of shavings and sawdust products utilized for

animal bedding.

18 9 0.23

479

135

38

0

50

100

150

200

250

300

350

400

450

500

Residential

construction

Residential

remodeling

Commerical/

industrial uses Highway

construction Mobile home

construction Railway

shipping

Figure 4—Annual Colorado consumption

(2000) of oriented strandboard.
USDA For. Serv. Res. Pap. RMRS-RP-37. 2002. 9

Potential Opportunities for

New Products, Processing,

and Technology

New wood products could be made from small diameter trees if new processing facilities were built or

new technologies were introduced to the State. The

following is a list of the most likely possibilities.

Roundwood for Structural

Applications

Wolfe and Moseley (2000) conducted tests using

small diameter roundwood for value-added structural

applications where building codes permit their use. The

natural look of roundwood is well suited for rustic structures, and diameters of 6 inches or greater reduce flammability. Peeled posts and poles can be put together

using special connectors to form the framing for structures such as barns, sheds, picnic shelters, kiosks, and

other outdoor shelters. Strength testing and the applicability of this construction technique using Colorado

tree species will have to be researched. If this use

proved to be applicable, it could provide value-added

support to existing post and pole businesses. To date,

it has not been possible to estimate the volume and

value potential for the barn, shed, and outdoor shelter

market.

The Interior West Center at Colorado State University has a research project under way that is utilizing

short length, small diameter logs in attractive log home

construction. This project is attempting to update a

time-honored building method known as “piece-onpiece” construction. To date, higher quality ponderosa

pine logs have performed surprisingly well as construction material in this project.

Another project in Arizona is successfully using

small diameter logs in traditional hogan construction

for the Navajo Nation (Indigenous Community Enterprises 2002).

Wood Pellets

The potential for wood pellet production has been

researched extensively (NEOS 1993). Wood pellets

provide comfortable heat and are a low air pollution

alternative to burning firewood. Currently 100 percent of all wood pellets used in Colorado are imported.

Current average annual consumption is estimated at

60,000 tons and had a value of $8.8 million in 1999. If

energy prices continue to increase, consumption may

rise dramatically. The sticking points for wood pellet

manufacture are a consistent supply of wood wastes

from higher value product manufacturing, in quantities sufficient to meet pellet plant economies of scale.

Existing facilities that have potential to produce pellets, such as lumber mills, are having trouble obtaining

a consistent supply of raw material that would allow

them to invest in pelletization technology to deal with

potential residues. Assistance in the form of low cost

loans or other incentives could encourage further investment in this technology.

Biomass Energy

Trees efficiently convert solar energy into wood fiber and thus provide a natural, renewable energy source.

Wood residues left over from manufacturing processes

are also potential sources of energy for Colorado. Wood

chips may be used directly in combustion processes,

as a supplement to other energy materials such as coal,

or processed into a derivative product such as ethanol.

There are distinct air quality benefits associated with

burning wood in place of, or as a supplement to, coal.

Wood is lower in sulfur content than hydrocarbon

fuels and therefore can reduce emissions such as sulfur dioxide. However, the use of wood has been restricted because wood is lower in BTU content than

other fuels, has higher moisture content, and generally

costs more to use.

Research projects are currently under way at Colorado State University to evaluate the feasibility of using chipped material from the forest as an energy fuel.

These studies involve co-firing wood chips with coal

at a cement plant and an electric power plant in Colorado. Because of the relatively low cost of coal, reducing chipping and removal costs will be necessary

to economically burn wood at this time. Developing

new wood chip based fuels such as pellets or briquettes

may improve the economics and resolve handling problems associated with chipped wood. If we can find

ways to increase BTU levels, reduce moisture content,

and lower costs, wood chips and/or residues could become an important energy fuel. At the present time,

wood chip costs are being subsidized in these studies.

The principal removal costs are chipping, loading, and

hauling. However, when wood residues are removed

from the forest in conjunction with higher value products, costs are reduced and the feasibility for the use of

chips is improved.

There is reason to be cautiously optimistic that wood

chips from the forest can become an energy fuel in

Colorado. It appears that the future for this will depend upon several factors. These include the market

price levels for traditional energy sources such as coal,

reduction of wood chip moisture content, additions to
10 USDA For. Serv. Res. Pap. RMRS-RP-37. 2002.

increase wood chip BTU’s, improvements in harvesting and transporting wood chips, the design of forest

restoration projects to distribute costs over higher value

products, and the availability of government subsidies

for renewable energy.

Composite Products

The mixing of wood fiber with plastic for extrusion

into composite products is an intriguing process and a

viable possibility for utilizing recycled plastic and wood

residues. This process could combine two existing

waste streams into the creation of a usable product.

Some research will be necessary to determine the types

of waste materials that can be used effectively. Based

on findings to date, commercial composite processing

equipment is not currently operating within Colorado.

However, the technology of extrusion is not unique and

has been used to produce other products. Whether this

technology can use wood removed directly from the

forest is yet to be determined.

Composite decking material made of recycled plastic and wood fiber is an example of a product that could

compete effectively in markets. Composite lumber use

is increasing and constitutes about 5 percent of the

decking market. In Colorado, the current retail value

of this market is estimated at approximately $2.37 million annually.

Cement-Wood Products

Cement is a product made in considerable quantities by plants along the Colorado Front Range. Products made with cement and wood hold potential for a

number of uses. This is another product area that merits further investigation. Estimate of annual consumption (volume and value) have not been determined for

cement-wood products use in the State.

Pine Excelsior

In the Pines Partnership Project (Lynch and others

2000) some ponderosa pine was used to create pine

excelsior as an experiment to develop a new erosion

control product. Excelsior is made by debarking a log,

allowing it to dry, cutting the log into segments, and

then shaving long thin strips of wood from the segment. The long thin strips then can be used for packing material, erosion control pads, and several other

products. Aspen is the preferred species for excelsior.

While the pine excelsior experiment conducted in

southwestern Colorado was not successful for erosion

control because of concerns about the reaction of seed

germination to pine terpenes, it did raise interesting

possibilities for other new products. Further testing

and analysis should be done to explore possibilities of

utilizing pine and white fir for excelsior products. The

potential for this market is not known.

Wood Pulp

Using clean wood chips from the forest for wood

pulp is another potential outlet for small diameter material. Thermo-mechanical pulp plants have low water demands and low pollution levels. In addition, combining wood pulp with recycled newsprint pulp offers

an opportunity to meet the demand for some of

Colorado’s paper products. Newsprint from Colorado

currently goes into landfills or is recycled. Recycling

involves shipping newsprint long distances to processing plants in other States.

In the thermo-mechanical pulping process, trees are

cut in the forest, debarked, and chipped. Clean chips

are delivered to the mill in truck trailers and processed into pulp at the plant using high levels of heat.

Either inked or de-inked recycled newsprint pulp can

be added at this point in the process, depending on

the final product desired. Pollution does occur in

the process but is relatively low compared to traditional methods of pulping wood. Paper recycling also

introduces pollution. Using 2000 population figures

supplied by the U.S. Census Bureau, Colorado citizens

use an estimated 875,000 tons of paper with a value of

$672 million and 722,000 tons of paperboard with a

value of $349 million each year. Recycling rates of 70

percent in some counties indicate the volume of recycled material available and suggest that large

amounts of paper and paperboard are still entering landfills.

Thermo-mechanical pulp plants are expensive to

build. Recent estimates of $700 to $750 million are

realistic. In addition, power generation would probably need to accompany such a plant at a cost of somewhere near $250 million. A pulp plant would need to

be sited in a location accessible to areas in critical need

of thinning along the Colorado Front Range, an area

noted for high land prices. In addition, no one will

build a plant unless they can be guaranteed a consistent supply of wood chips to amortize the cost of the

plant and make a profit. This would mean long-term

contracts for wood from State and National Forest

lands. In spite of potential barriers, this opportunity

deserves additional study given the huge problem of

wood utilization from anticipated forest restoration

thinning and the demand for paper products in Colorado.

At this time, another alternative appears to be developing. A thermo-mechanical pulp plant has been
USDA For. Serv. Res. Pap. RMRS-RP-37. 2002. 11

seriously discussed for construction in New Mexico.

It is at least 3 years away from operation. However,

chips from southern Colorado and the Front Range

might be shipped by rail to this plant for processing.

Again, costs of harvesting and processing chips plus

transportation become critical to the feasibility of using this plant as an outlet for small diameter wood.

Other Opportunities

Since the publication of “Wood Use at the Turn of

the Century,” potential markets for small diameter

wood products continue to be discovered. For example,

contact was made with a business installing concrete

tile roofs that needed 1-inch x 2-inch rough sawn lumber strips. These strips are placed on the roof before

the tiles are laid and can be made of relatively low

quality lumber. Currently all of the material being used

is shipped in from out of state. Concrete tile roofs are

gaining market share because of fireproofing, hail resistance, and roof esthetics. Therefore, this market for

rough lumber is expected to increase.

Also, short strips of low quality veneer are used in

packaging bricks for shipment. These strips are used

above the holes in brick packs to stabilize the lifting of

the packs by forklifts. One company uses over a million of these strips annually. They are all imported

from Texas.

Certainly not all the potential uses for small diameter trees have been discovered yet. Wood is such a

versatile material and it is almost certain that other uses

will arise. The work presented here will hopefully stimulate others to develop new product ideas that will further

efforts to restore Colorado forests to good health.

Conclusion

Markets for all types of wood products clearly exist. There are substantial opportunities to use small

diameter wood in many existing markets and there are

interesting opportunities for new products, processing,

and technology as well. No one ideal use or one

“silver bullet” solution exists for the problem of small

diameter wood utilization. In fact, a stable, diverse

wood products industry is the most desirable future

for dealing with this problem. Also, it is unlikely that

all the possibilities for utilizing small diameter wood

were presented here. If a thinning program is initiated

and agencies encourage businesses and communities

to participate, innovative and creative people will find

many other ways to use wood to meet society’s needs.

References

CSFS. 1998a. Chuck Dennis, personal communication. Wildland

Fire Coordinator, Colorado State Forest Service, Broomfield, CO.

CSFS. 1998b. Colorado forest industries directory. Colorado State

Forest Service. Colorado State University, Fort Collins, CO.

Indigenous Community Enterprises. 2002. Developing culturally compatible housing and employment opportunities in Native American communities through the restoration of traditional use lands. www.cba.nau.edu/ice/contents.htm.

Lynch, D. 2000. Summary report: forest restoration thinning

project on Denver Water Board property at Cheesman Reservoir, Trumbull sites, May 18–July 17, 2000. Department of

Forest Sciences, Colorado State University, Fort Collins, CO.

Lynch, D. and C. Jones. 1998. Mixed conifer demonstration

project, Gordon Creek forest restoration sale. Department of

Forest Sciences, Colorado State University, Fort Collins, CO.

Lynch, D. and K. Mackes. 2001. Wood use in Colorado at the turn

of the century. USDA Forest Service, Rocky Mountain Research Station, Research paper RMRS-RP-32.

Lynch, D., W. Romme and M. Floyd. 2000. Forest restoration in

southwestern ponderosa pine. Journal of Forestry. Vol. 98

No. 8

Lynch, D., W. Romme, P. Kemp and C. Garrison. 1998. Ecology

and economics of ponderosa pine forest restoration on the

Mancos-Dolores district of the San Juan National Forest. Summary report for the ponderosa pine partnership, Montezuma

County, CO.

Mackes, K., E. French, D. Lynch and J. Ward. 2000. The use of

white fir as bedding for research animals. Department of Forest Sciences, Colorado State University, Fort Collins, CO.

NEOS Corporation. 1993. Wood pellet manufacturing in Colorado: An opportunity analysis. State of Colorado, Office of

Energy Conservation, Denver, CO.

USDA Forest Service. 1996. Probability of catastrophic disturbance events. Region 2, Forest Service USDA. Denver, CO.

Wolfe, R. and C. Moseley. 2000. Small diameter log evaluation

for value-added structural applications. Forest Products Journal. Vol. 50. No. 10.
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