Lumber Recovery and

Deterioration of Beetle-Killed

Douglas-fir and Grand-fir in

the Blue Mountains of

Eastern Oregon

Dean L. Parry, Gregory M. Filip, Susan A. Willits

and Catherine G. Parks

United States

Department of

Agriculture

Forest Service

Pacific Northwest

Research Station

General Technical

Report

PNW-GTR-376

September 1996
Authors DEAN L. PARRY is a forester and SUSAN A. WILLITS is a research forest products

technologist, USDA Forest Service, Pacific Northwest Research Station, Forestry

Sciences Laboratory, P.O. Box 3890, Portland, OR 97208-3890; GREGORY M.

FILIP is an associate professor, Oregon State University, Department of Forest

Science, Forestry Sciences Laboratory 020, Corvallis, OR 97331-7501; and

CATHERINE G. PARKS is a research plant pathologist, USDA Forest Service,

Pacific Northwest Research Station, Forestry and Range Sciences Laboratory,

1401 Gekeler Lane, La Grande, OR 97850-3399.
Abstract Parry, Dean L.; Filip, Gregory M.; Willits, Susan A.; Parks, Catherine G. 1996.

Lumber recovery and deterioration of beetle-killed Douglas-fir and grand fir in the Blue

Mountains of eastern Oregon. Gen. Tech. Rep. PNW-GTR-376. Portland, OR:

U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station.

24 p.

The purpose of this study was to determine the effect of time since death over a

4-year period on the amount of usable product volume and value, and to determine

the species of fungi associated with wood deterioration in the stems of Douglas-fir

and grand fir trees killed by bark beetles in northeastern Oregon. Sap rot, caused

principally by Cryptoporus volvatus, increased significantly with years dead for both

Douglas-fir and grand fir, but there were no significant differences in sap rot among

d.b.h. (diameter at breast height) classes. Few insects were associated with defective

wood, probably because of the relatively dry condition of the wood. Log breakage

during logging in the live samples was less than 0.5 percent of the gross volume, and

the amount of wood too defective to remove from the woods was about 2.5 percent

in the dead Douglas-fir and 3.8 percent in the dead grand fir. Two-year-dead

Douglas-fir recovered about 8 percent less lumber volume than live and 1-year dead

Douglas-fir and all classes of dead grand fir. Three- and four-year dead Douglas-fir

combined lost another 7 percent in lumber volume. Average lumber value (dollars per

thousand lumber tally) and average log value (dollars per hundred cubic feet) analysis

showed no difference among the live and 1-year-dead Douglas-fir samples. Average

log value decreased about $60 from the live class to the grand fir dead class and

another $60 for the Douglas-fir dead. Contrary to popular belief, the grand fir did not

deteriorate as fast as the Douglas-fir or lose as much value as expected.

Keywords: Douglas-fir, Pseudotsuga menziesii, grand fir, Abies grandis, lumber

recovery, utilization, dead timber, western spruce budworm, Choristoneura

occidentalis, Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, fir engraver,

Cryptoporus volvatus, Trichaptum (Polyporus) abieinum, Fomitopsis pinicola.
Contents 1 Introduction

2 Literature Review

3 Objectives

3 Field Procedures

3 Timber Sample

6 Decay and Fungal Samples

6 Felling and Bucking

6 Wood Deterioration Estimate

7 Scaling and Log Grading

7 Sawing

10 Lumber Pricing

10 Analysis

11 Volume Recovery

11 Value Recovery

11 Decay Volumes

11 Results and Discussion

11 Decay and Fungi

15 Volume Recovery

18 Value Recovery

21 Conclusions

23 Literature Cited
Introduction Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is found from northern California

to British Columbia and as far east as the Rocky Mountains (Burns and Honkala

1990). In the inland Northwest, Douglas-fir and western larch (Larix occidentalis Nutt.)

are processed and marketed together as a species group and make up 24 percent of

all softwood lumber production. The total production of Douglas-fir and larch in 1993

was 2 billion board feet. It was used for dimension lumber, timbers, and studs, accounting for over 75 percent of log and lumber exports from eastern Oregon and

Washington (Warren 1994).

Grand fir (Abies grandis (Dougl. ex D. Don) Lindl.) is found in moister sites such as

stream bottoms and valleys or mountain slopes in the northwestern United States

and southern British Columbia. In the Inland Empire, it is found in southern British

Columbia, eastern Washington and Oregon, and the regions of western Montana and

northern Idaho west of the Continental Divide. It grows best on rich mineral soils in

valley bottoms but also will grow in pumice soils such as those found in central and

eastern Oregon, if rainfall is adequate (Burns and Honkala 1990). The primary uses

of grand fir lumber are dimension lumber, timbers, and studs (Western Wood Products Association 1995).

Since the late 1970s, Douglas-fir in the Blue Mountains of eastern Oregon has been

subjected to outbreaks of a defoliator, western spruce budworm (Choristoneura

occidentalis Freeman), and a bark beetle, the Douglas-fir beetle (Dendroctonus

pseudotsugae Hopkins). Grand fir also has been subjected to severe defoliation by

western spruce budworm and attacks by another bark beetle, the fir engraver

(Scolytus ventralis LeConte). According to rainfall records collected by the Oregon

Climate Service, below normal rainfall was received in the La Grande, Oregon, area

from 1985 through 1992. According to data from the Oregon Climate Service, for

those years, rainfall amounts dropped as low as 71 percent and was no greater than

86 percent of the previous yearly normal. During the drought period, most of the

shortfall occurred from September through April and produced much less snowpack

than usual.1 This drought reduced the natural defense mechanisms of the trees to an

extent such that the trees could not resist the attacks of bark beetle infestations

(Wright and Lejeune 1967). The result has been significant mortality of Douglas-fir

and grand fir trees. Our observations indicated that the most severe Douglas-fir

mortality occurred on dry sites where ponderosa pine (Pinus ponderosa Dougl. ex

Laws.) has historically been the more common species.

About 100 million board feet of Douglas-fir and over 280 million board feet of grand

fir in the Blue Mountains of Oregon and Washington has been killed as a result of

drought and insect epidemics from 1992 through 1994 (USDA 1994). The rate of

deterioration of beetle-killed trees is of primary concern to forest managers and is

important in the scheduling of prompt salvage operations in affected forests. Resource managers need guidelines to use in planning for management of this important forest resource. One alternative is to remove the dead trees for production of

wood products. The purpose of this study was to determine the effect of time since

death on the amount of usable product volume and value. We also determined the

species of decay-causing fungi associated with wood deterioration in the stems of

trees killed by bark beetles over a 4-year period in northeastern Oregon.

1 Personal communication. 1995. Chris Scalley, Oregon

Climate Service, Oregon State University, Corvallis, OR

97331-2209.

1
Literature Review It is important to understand the types of deterioration agents and their progression

in trees that are stressed and dying or recently dead. This information is essential to

developing reliable estimates of the rates of decay and the impact of the deterioration

on volume and value loss. The following review provides background on the insects

and fungi and on existing work covering lumber volume and value loss in dead

timber.

The Douglas-fir beetle and fir engraver are bark beetles and they mine only in the

cambium. Except for loosening the bark and serving as a carrier of fungal spores,

they cause no damage to wood. Wood boring beetles are the only insects causing

direct significant wood damage (Wright and Harvey 1967).

Both species of bark beetle have a history of attacking trees that are physiologically

stressed. The Douglas-fir beetle has one generation annually. Adults and large larvae

overwinter, with adults predominating. Depending on area and weather, the overwintering adults emerge and attack from April to June. Some of the adults reemerge,

attack additional trees, and establish a second brood. Adults from overwintering

larvae emerge and attack in July and August. “Reddish or yellowish boring dust

caught in bark crevices or around the base of trees is the usual evidence of attack by

the Douglas-fir beetle. No pitch tube is formed but resin may exude from upper attacks. The foliage of attacked trees turns yellow, then sorrel, and finally reddish brown

in late summer, in fall, or in early spring, depending upon the region, time of attack,

and weather” (Furniss and Carolin 1977: 357).

The Douglas-fir beetle is associated with the stain fungus Ophiostoma pseudotsugae

(Rumb.) von Arx, but relatively little is known about the relation between beetle

and fungus or about the succession of fungi or insects following infection by O.

pseudotsugae. Extensive studies have been done on the fir engraver and its associated stain fungus, Trichosporium symbioticum Wright, (Berryman 1969, Filip and

others 1989, Raffa and Berryman 1982, Wright 1935), but for it too, there is a lack of

information on postinfection successional fungi and insects.

Wright and Wright (1954) briefly explored fungal succession in beetle-killed Douglasfir in coastal Oregon and Washington. They found that the pouch fungus (Cryptoporus

volvatus (Pk.) Shear.) frequently was found in trees killed 1 year previously by beetles. Sporophores of this fungus indicated a shallow rot of the sapwood. On trees

dead for 2 or more years, rudimentary sporophores of the red-belt fungus (Fomitopsis

pinicola (Swartz ex Fr.) Karst.) were common. Presence of these sporophores indicated an advanced stage of decay where the sapwood was destroyed and the heartwood sometimes invaded. Both species of fungi have been isolated from the Douglasfir beetle (Castello and others 1976), which may be a vector (carrier) for these decay

fungi as suggested by Wright and Wright (1954).

Thomas and Craig (1958) also briefly investigated the succession of fungi in dead

Douglas-fir in interior British Columbia. They found that over a 5-year period, most of

the sap rot was associated with two species of fungi: Trichaptum (Polyporus)

abietinum (Dicks. ex Fr.) Ryv., and F. pinicola. Cryptoporus volvatus rarely caused

extensive decay, although the abundance of its fruiting suggested greater decay than

actually occurred. Eleven other species of fungi were identified. Heart rot fungi, those

present before tree mortality, were not an important factor in the deterioration of dead

Douglas-fir.

2
Although similar studies concerning deterioration of dead grand fir have not been

reported, it is common knowledge among foresters that dead grand fir deteriorates

much faster than Douglas-fir, and conks of C. volvatus are often found on trunks of

dead grand fir and Douglas-fir trees. The rates of tree deterioration and causal fungi

need to be studied. Most of the investigations concerning the succession of fungi

associated with dead trees have been done in the relatively wet climate of coastal

Oregon. The much drier climatic conditions in eastern Oregon may be sufficiently

different to affect species of fungi and resultant deterioration rates of dead Douglas-fir

and grand fir.

Use of the dead material has the advantage of reducing fuel loads and providing

wood products for the consumer. Before salvage of the material can be considered,

basic information about the products that can be recovered from the dead material is

needed. It has been shown (Fahey and others 1986, Snellgrove and Ernst 1983) that

product volume and value depend on the type of product produced and the timesince-death of the trees. Volume recovery is impacted by both sap rot and weather

checking. Sap rot affects the ability to produce lumber from the outer section of the

log, and weather checks produce splits in the logs and boards that result in narrower

lumber. Value recovery is more significantly impacted in species such as ponderosa

pine or western white pine (Pinus monticola (Dougl. ex D. Don)), which produce highvalue appearance-grade lumber and in which blue stain in the sapwood occurs within

the first year after death. Information available on Douglas-fir shows that it has thin

sapwood and that trees 3 to 4 years dead in western Oregon and northern California

lose 50 percent of their cubic volume (Kimmey and Furniss 1943). Another study on

Douglas-fir (Wallis and others 1974) found a loss in lumber value of 7 percent,

11 percent, and 14 percent for trees dead 2, 3, and 4 years, respectively. True fir

species have very thin bark and very thick sapwood and lose 50 percent of their

cubic volume by the end of the second year after death (Kimmey 1955). A study of

lumber recovery from live and 2-year-dead grand fir and white fir (Abies concolor

(Gord. and Glend.) Lindl.) in eastern Oregon found a 6-percent increase in logging

and handling losses, an 8-percent loss in lumber volume, and a 24-percent loss in

lumber value for the dead sample (Snellgrove and Fahey 1977).

Objectives There were three objectives in this study: to develop product recovery information for

live and beetle-killed Douglas-fir and grand fir trees from eastern Oregon, to determine the rate of volume and value loss that occurs in beetle-killed trees over time,

and to identify biotic agents responsible for deterioration of Douglas-fir and grand fir.

Field Procedures The sample for this study was selected from two sources, the Starkey Experimental

Forest, in the Wallowa-Whitman National Forest of northeastern Oregon, and, the Vail

District, Bureau of Land Management (BLM), near Union, Oregon. Twelve sites were

used for sample selection in the Starkey Experimental Forest, and one site was selected from BLM land. The BLM site yielded 3 Douglas-fir and 68 grand fir trees. The

Starkey Experimental Forest yielded 147 Douglas-fir and 39 grand fir trees.

The sampling procedure for both live and beetle-killed trees was designed to represent the variation of size and quality of the resource, and not to be a representative

sample of the average log mix that a mill might process in a normal production run.

Sampling criteria for Douglas-fir was diameter at breast height (d.b.h.) and grade of

the butt 16-foot log from the inland Douglas-fir saw-log grading system (Lane 1964).

The grand fir sample was stratified by d.b.h. only. Diameter at breast height for both

species ranged from 10 to 30 inches and was selected by 5-inch diameter classes

Timber Sample

3
Table 1—Number of sample trees by deterioration and diameter classes, log

grade, and species

Douglas-fir inland log grade

Deterioration and diameter class 1 2 3 Grand fir

Inches −−−−−−− Number of trees −−−−−−

Live:

10.0 to 15.9 5 5 4 8

16.0 to 20.9 4 6 4 11

21.0 to 25.9 3 3 6 9

26.0 to 30.9 4 4 5 6

Total 16 18 19 34

1-year dead:

10.0 to 15.9 1 1 0 6

16.0 to 20.9 2 0 1 5

21.0 to 25.9 0 1 0 7

26.0 to 30.9 1 0 1 2

Total 4 2 2 20

2-year dead:

10.0 to 15.9 3 3 1 0

16.0 to 20.9 3 3 2 0

21.0 to 25.9 2 3 3 0

26.0 to 30.9 1 1 1 0

Total 9 10 7 0

3-year dead:

10.0 to 15.9 3 3 1 11

16.0 to 20.9 3 3 3 9

21.0 to 25.9 3 3 3 9

26.0 to 30.9 3 3 4 2

Total 12 12 11 31

4-year dead:

10.0 to 15.9 3 3 2 9

16.0 to 20.9 3 3 3 9

21.0 to 25.9 4 3 3 4

26.0 to 30.9 3 3 3 0

Total 13 12 11 22

4
(table 1). To select a sample that included trees dead up to 4 years, trees were selected in 1991, 1992, and 1993. Because of the difficulty of determining with certainty

the year of death of trees that have been dead for several years, freshly killed trees

were selected each year. Only presently dying, 1- or 2-year-dead trees were selected

in any given year. Personnel from the La Grande Ranger District of the WallowaWhitman National Forest were present at the beginning of sample selection to train

the sample selection team in identifying the year of death.

A list of traits follows that was used to determine when a Douglas-fir and grand fir

tree died:

Douglas-fir

Part of tree: What to look for:

Trees killed during the current year

Bark surface Fresh, rich brown frass in bark crevices or hanging from spider

webbing

Beneath bark Cambium discolored, adult galleries present and containing

eggs or larvae

Needles Green or slightly faded

Conks None present

Trees killed the previous year

Bark surface Frass somewhat faded looking compared to fresh; washed

from spider webs into bark crevices

Beneath bark Cambium contains old galleries and frass; gallery-mining

evidence on surface of wood

Needles Brick-red color; nearly all still present on tree

Conks Pouch fungus conks present on the bark are soft and moist

Trees killed 2 years ago

Bark surface Most frass has been washed from the bark crevices and

deposited at base of tree

Beneath bark Although all bark is present, it is quite loose from the bole

of the tree

Needles Only 25 percent or less of the needles remain; those present

are still brick red

Conks Pouch fungus conks are present, and open on the bottom;

some conks have fallen off; those still present are hard

and dry

5
Grand fir

Part of tree: What to look for:

Trees killed during the current year

Bark surface 0.06-inch adult exit holes

Beneath bark Fir engraver galleries present around the circumference of the

tree (tree girdled, bark loose)

Needles Slightly faded green

Conks None present

Trees dead the previous year

Bark surface Adult insect exit holes

Beneath bark Galleries present; fungus mycelium present; incipient

decay present in wood

Needles Faded green to light brown color

Conks Pouch fungus conks present are soft and moist

A subsample of trees were sampled in June 1993 at the Starkey Experimental forest

(mostly Douglas-fir) and from BLM land southeast of Union, Oregon (mostly grand fir).

For the decay and fungal sample portion of this study, 204 trees were sampled (117

Douglas-fir and 87 grand fir), with at least 25 trees from each of four mortality classes

(dead 0, 2, 3, or 4 years) for Douglas-fir and at least 20 trees for three mortality

classes (dead 0, 3, or 4 years) for grand fir. Within each mortality class, the trees

were selected based on d.b.h., with at least three trees for each diameter class.

Felling and Bucking Trees were felled and bucked into the cooperating mill’s preferred log length of 40

feet. Other log lengths were determined by merchantable tree length or the occurrence of breaks down to a minimum top diameter of 5.6 inches. Each log was

identified with tree number and position within the tree. This tree-log identification

was maintained throughout the scaling and sawing phases of the study.

After the subsample of trees selected for decay and fungal evaluation were felled,

the following data were collected for each tree:

1. Total height (ground line to tip, nearest foot).

2. Mean diameter inside bark (nearest inch) at stump and top of each log.

3. Mean diameter of sap rot (if in pockets) at stump and top of each log.

4. Mean diameter of heartwood (Douglas-fir only) at stump and top of each log.

5. Mean diameter of sound wood (undecayed wood) at stump and top of each log.

6. Mean diameter of heart rot (internal decay) at stump and top of each log.

The cubic foot volume of each tree, of sap rot, of heart rot, of heartwood, and

of sound wood remaining was determined by using Smalian’s formula,

volume = (A + a)/ 2 L,

where: A = basal area at large end of log,

a = basal area at small end of log, and

L = log length.

Decay and Fungal

Samples

Wood Deterioration

Estimate

6
The sap rot, heart rot, heartwood, sound, and total volumes were calculated for each

log. The volume for each tree is the sum of each log in the tree. The volume of sap

rot was calculated directly or as the total volume minus the sound volume and any

internal decay (if present). No deduction was given for defects such as cracks,

checks, or shake in this portion of the study.

Samples of fungi (primarily Hymenomycetes) were systematically collected from each

log as follows: a 2-inch thick stem disk was removed from the larger end of each log

with a chain saw. A pie-shaped sample of wood (pith to bark) containing stain or

decay, if present, was removed from each disk. If no sap rot was present in a tree,

then samples from only two disks per tree were taken. Each wood sample was

labeled by log and tree number, placed in a plastic bag, transported to the laboratory,

and refrigerated until processing.

In the laboratory, each wood sample was aseptically split. Five wood chips (0.2 by

0.2 by 0.4 inch) were aseptically removed from pith to cambium with a wood gouge

and labeled as to position (1=bark, 5=pith). The type of wood tissue (clear, stained,

decayed) was recorded for each wood chip. Chips were placed onto 2 percent malt

agar in culture tubes, one chip per tube. All culture tubes were incubated in the dark

at room temperature, and all fungi identified to species, if possible, by using appropriate taxonomic keys and techniques. The results are displayed in tables 2 and 3.

Species of bark beetles were collected from wood samples, placed in vials of ethanol,

and identified from appropriate taxonomic keys.

Scaling and Log Grading In the mill yard, the logs were rolled out for a woods length “as presented” scaling.

Scaling was done by using both Scribner (USDA Forest Service 1985) and cubic

rules (USDA Forest Service 1991). Each defect was identified by type so that it was

possible to separate existing defects from defects related to the death of the tree,

such as sap rot and weather check. Next, the logs were bucked into mill sawing

lengths of 16 to 20 feet and scaled as mill-length logs by using the same scaling

systems. The inland Douglas-fir saw-log grading system (Lane 1964) also was

applied to the mill-length logs.

Sawing The study logs were sawn at a small sawmill in eastern Oregon whose equipment

consisted of a circular saw headrig, board edger, and chain saw for trimming rough

board ends. Items produced were 2-inch dimension lumber from 4 to 12 inches wide,

3-and 4-inch thick planks 12 inches wide, heavy timbers from 8 by 8 to 12 by 12

inches, and occasional 4/4-inch boards. The lumber was graded by a certified

Western Wood Products Association (WWPA) grader in rough green condition

according to the following sections from the grading rule book (WWPA 1988):

Lumber item WWPA rule

1-inch-thick, 4- to 12-inch-wide boards Commons

1- to 2-inch-thick, 4- to 12-inch-wide selects Select grades

2 inches thick, 4 inches wide Structural light framing

2 to 4 inches thick, 6 to 12 inches wide Structural joists and planks

5 inches and thicker, 5 to 16 inches wide Beams and stringers

7
Table 2—Frequency of clear wood, decay, and stain in wood chips of Douglas-fir killed by bark beetles in

northeastern Oregon, by years dead and bole position

Bole positionb

Chip Years Stump First Second Average

positiona dead Cc Sc Dc CS D C SDC S D

−−−−−−−−−−−−−−−−−−−−−−− Percent −−−−−−−−−−−−−−−−−−−−−−

1 0 97.1 0 2.9 100.0 0 0 100.0 0 0 99.0 0 1.0

2 23.5 47.1 29.4 76.5 5.9 17.7 92.9 0 7.1 64.3 17.6 18.1

3 37.5 21.9 40.6 53.1 0 46.9 74.1 3.7 22.2 54.9 8.5 36.6

4 33.3 10.0 56.7 73.3 0 26.7 76.0 4.0 20.0 60.9 4.7 34.4

2 0 97.1 0 2.9 100.0 0 0 100.0 0 0 99.0 0 1.0

2 76.5 11.8 11.8 94.1 0 5.9 92.9 0 7.1 87.8 3.9 8.3

3 90.6 3.1 6.3 78.1 0 21.9 88.9 0 11.1 85.9 1.0 13.1

4 80.0 0 20.0 93.3 0 6.7 80.0 0 20.0 84.4 0 15.6

3 0 97.1 0 2.9 100.0 0 0 100.0 0 0 99.0 0 1.0

2 100.0 0 0 100.0 0 0 100.0 0 0 87.8 0 0

3 90.6 3.1 6.3 100.0 0 0 100.0 0 0 85.9 1.0 2.1

4 96.7 0 3.3 100.0 0 0 92.0 0 8.0 84.4 0 3.8

4 0 97.1 0 2.9 100.0 0 0 100.0 0 0 99.0 0 1.0

2 100.0 0 0 100.0 0 0 100.0 0 0 100.0 0 0

3 90.6 0 9.4 100.0 0 0 100.0 0 0 96.9 0 3.1

4 96.7 0 3.3 100.0 0 0 100.0 0 0 98.9 0 1.1

5 0 97.1 0 2.9 100.0 0 0 100.0 0 0 99.0 0 1.0

2 94.1 0 5.9 100.0 0 0 100.0 0 0 98.0 0 2.0

3 90.6 0 9.4 100.0 0 0 100.0 0 0 96.9 0 3.1

4 93.3 0 6.7 100.0 0 0 96.0 0 1.0 96.4 0 3.6

Average 0 97.1 0 2.9 100.0 0 0 100.0 0 0 99.0 0 1.0

2 78.8 11.8 9.4 94.1 1.2 4.7 97.1 0 2.9 90.0 4.3 5.7

3 80.0 5.6 14.4 86.3 0 13.8 92.6 0.7 6.7 86.3 2.1 11.6

4 80.0 2.0 18.0 93.3 0 6.7 88.8 0.8 10.4 87.4 0.9 11.7

a Chip position: 1 = bark, 2-4 = between bark and pith of disk, 5 = pith.

b Stump = stump disk, first = top of first log, second = top of second log.

c C = clear wood, D = decayed wood, S = stained wood.

8
Table 3—Frequency of clear wood, decay, and stain in wood chips of grand fir killed by bark beetles in

northeastern Oregon, by years dead and bole position

Bole positionb

Chip Years Stump First Second Average

positiona dead Cc Sc Dc C S D C SD C S D

−−−−−−−−−−−−−−−−−−−−−−− Percent −−−−−−−−−−−−−−−−−−−−−

1 0 86.2 0 13.8 75.9 6.9 17.2 77.3 13.6 9.1 79.8 6.8 13.4

3 74.3 0 25.7 37.1 2.9 60.0 63.3 3.3 33.3 58.3 2.1 39.7

4 23.8 4.8 71.4 19.1 4.8 76.2 50.0 5.6 44.4 31.0 5.0 64.0

2 0 86.2 6.9 6.9 82.8 3.5 13.8 81.8 9.1 9.1 83.6 6.5 9.9

3 85.7 0 14.3 45.7 2.9 51.4 63.3 3.3 33.3 64.9 2.1 33.0

4 33.3 4.8 61.9 33.3 4.8 61.9 55.6 0 44.4 40.7 3.2 56.1

3 0 93.1 3.5 3.5 89.6 6.9 3.5 81.8 9.1 9.1 88.2 6.5 5.3

3 88.6 0 11.4 77.1 2.9 20.0 66.7 0 33.3 77.5 1.0 21.6

4 52.4 4.8 42.9 61.9 9.5 28.6 55.6 5.6 38.4 56.6 6.6 36.6

4 0 89.7 3.5 6.9 93.1 3.5 3.5 95.5 4.5 0 92.7 3.8 3.5

3 85.7 0 14.3 71.4 2.9 25.7 80.0 0 20.0 79.0 1.0 20.0

4 61.9 4.8 33.3 66.7 4.8 28.6 72.2 0 27.8 66.9 3.2 29.9

5 0 86.2 3.5 10.3 86.2 6.9 6.9 90.9 9.1 0 87.8 6.5 5.7

3 85.7 0 14.3 88.6 0 11.4 96.7 0 3.3 90.3 0 9.7

4 61.9 4.8 33.3 76.2 0 23.8 77.8 5.6 16.7 72.0 3.4 24.6

Average 0 88.3 3.5 8.3 85.5 5.5 9.0 85.4 9.1 5.5 86.4 6.0 7.6

3 84.0 0 16.0 64.0 2.3 33.7 74.0 1.3 24.7 74.0 1.2 24.8

4 46.7 4.8 48.6 51.4 4.8 43.8 62.2 3.3 34.3 53.4 4.3 42.2

a Chip position: 1 = bark, 2-4 = between bark and pith of disk, 5 = pith.

b Stump = stump disk, first = top of first log, second = top of second log.

c C = clear wood, D = decayed wood, S = stained wood.

9
Lumber Pricing Lumber and log values were calculated by applying prices from the WWPA (1993) to

the volume and grade of lumber produced for each log. Lumber grade groupings

were made by combining products of approximately equal value. Lumber grade

groupings and prices used were as follows:

Average value per

thousand board feet

Grade group Lumber grades included Douglas-fir Grand fir

Select structural D & better selects and Select Structural

grade dimension lumber 570.38 532.31

Construction 2 & better common and Construction

grade dimension lumber 436.72 447.61

Standard 3 common and Standard grade

dimension lumber 412.53 428.81

Utility 4 common and Utility grade

dimension lumber 267.61 250.15

Economy 5 common and Economy grade

dimension lumber 172.30 169.69

Analysis This study was conducted to provide (1) volume and value recovery information for

live and beetle-killed Douglas-fir and grand fir, (2) information on what changes occur

in volume and value in dead trees over time, and (3) identification of biotic agents

responsible for deterioration of Douglas-fir and grand fir.

The variables used in analyzing objectives 1 and 2 were lumber volume recovery and

grade, and value recovery of lumber or logs. The sources of variation used to analyze

the data were log diameter, log grade, and number of years dead. Standard regression techniques were used, and the best model form for each dependent variable was

chosen by using the coefficient of determination (R2

) and standard error of the estimate as criteria. Separate regression equations were estimated for live Douglas-fir

and grand fir and for each year since death, and a covariance analysis or analysis of

variance was done to test for differences among these. Deterioration class samples

were combined when no differences were found. All test results were evaluated at

the 0.05 probability level.

Model forms tested were:

volume or value = bo + b1D,

= bo + b11/D,

= bo + b1D+b21/D,

= bo + b1D+b21/D2

, and

= bo + b1D+b21/D + b31/D2

.

10
Volume Recovery Lumber volume recovery was analyzed by using cubic recovery percent (CR%), lumber recovery factor (LRF), and overrun. Cubic recovery percent is the volume of

rough green lumber expressed as a percentage of log volume. Lumber recovery factor is the number of board feet of lumber recovered per cubic foot of log. Overrun is

the ratio of board foot lumber tally to board foot net Scribner scale. Prediction models

using CR%, LRF, and overrun as dependent variables were tested by using log

small-end diameter and transformations thereof as independent variables.

In addition, estimates of volume loss related to sap rot and weather check were made

for each class of dead logs. Log scale estimates of defect and their relation to lumber

volume loss were analyzed for the noncull and cull logs (logs less than one-third

sound). A technique using bias and accuracy estimates was used to evaluate the effectiveness of the scaling defects (Fahey and others 1981). This technique compares

the recovery of defective logs with sound logs of equivalent volume. The yield of lumber from sound logs was established by regressing lumber volume over gross cubic

log volume. With this regression line for sound logs as a base, the loss in lumber

tally for each defective log is the actual lumber tally minus the predicted lumber tally

for the net scale volume of the log. To evaluate the effect of a single defect, such as

sap rot, the sample was separated into logs with multiple defects, only sap rot, and

only weather check. Bias and accuracy were calculated for each defect sample, species, and deterioration class.

Value Recovery Two variables will be used to express value recovery: dollars per thousand board

feet of lumber tally ($/MLT) and dollars per hundred cubic feet of gross log volume

($/CCF). Dollars per thousand board feet of lumber tally represents the average value

of the lumber produced from the log. Dollars per hundred cubic feet represents the

value of the log including differences due to the amount of lumber that can be recovered, which is affected by the amount and type of defect.

The percentage of lumber volume recovery by product grade groupings also will be

estimated by deterioration classes. Prediction formulas for the percentage of lumber

volume will be additive for all lumber grade groupings.

Decay Volumes Analysis of variance (NPAR1WAY procedure; SAS 1987) was used to determine

significant (P<0.05) differences in percentage of sap rot volume among tree mortality

classes (three or four) and tree diameter classes (four).

Of the 117 Douglas-fir and 87 grand fir trees sampled in this portion of the study,

total age averaged 161 and 121 years, d.b.h. averaged 20 and 19 inches, and total

height averaged 90 and 89 feet, respectively. Sap rot increased significantly (p =

0.0001 [Douglas-fir] and 0.0003 [grand fir]) with years dead, but there were no

significant differences in sap rot among d.b.h. classes, probably because of the dry

weather conditions. The following tabulation shows the increase in percentage of sap

rot for trees as time-since-death increases:

Results and

Discussion

Decay and Fungi

11
Percentage of sap rot by years dead2

Species 0 2 3 4

Percent

Douglas-fir 0 (35) 1.0 (18) 8.1 (33) 11.4 (31)

Grand fir 0 (30) — 1.7 (36) 8.0 (21)

Three years after bark beetle-caused mortality, Douglas-fir had 8.1 percent sap rot

and grand fir had 1.7 percent. In a west-side study of Douglas-fir killed by bark

beetles, 15 percent of the total cubic volume had sap rot after 3 years (Wright and

Wright 1954). Sapwood in Douglas-fir averaged 39.4 percent in our present east-side

study and was 22 percent in the earlier west-side study (Wright and Wright 1954).

Because the east-side trees had a greater proportion of sapwood than did the westside trees sampled, they should have had a higher percentage of sap rot. It also was

surprising that Douglas-fir had more sap rot than grand fir, because grand fir is generally considered more decay prone. Perhaps differences in deterioration rates occurred

because the sampled Douglas-fir and grand fir were from different sites. Another possible explanation is that attacks by the Douglas-fir beetle (and vector spores) were

much greater than attacks by the fir engraver, thereby resulting in more decay in

Douglas-fir than in grand fir.3

We speculate that the extremely dry conditions over the duration of the study were

not conducive to wood decay in either species. Although conks of Cryptoporus

volvatus were present on almost all dead trees of both species, relatively little decay

had gone beyond the inner bark. Relative moisture contents of wood samples collected in June 1993 averaged 53.7 percent for stump disks, 33.0 percent for disks at

midbole, and 29.8 percent at the upper portions of trees. This is sufficient moisture to

allow decay (Boyce 1961), but winter and spring of 1992-93 were wetter than the

average for the previous 3 years. Also, wood moisture content may have been much

lower throughout summer and fall. During winter, when precipitation is greatest, temperatures are generally too low in northeastern Oregon for decay to occur.

In addition to the dry climatic and soil conditions, study trees sustained several consecutive years of spruce budworm defoliation of current year foliage and had a much

reduced complement of mostly old needles before they died. Because older foliage is

less active in both photosynthesis and transpiration (Lassoie and others 1985), the

crown condition may have contributed to a gradual overall reduction of uptake and

storage of water in the bole.

2 Number in parentheses is the number of trees sampled.

3 Personal communication. 1995. Craig Schmitt, Zone

Pathologist, Blue Mountains Pest Management Zone,

Wallowa-Whitman National Forest, 1401 Gekeler Lane,

La Grande, OR 97850.

12
Most of the decay was caused by Cryptoporus volvatus, and most of the isolations of

decay fungi were of that fungus, which is not surprising considering the abundance

of conks. No other species of conks were found, even in trees dead for 4 years. This

differs from the west-side study where conks of Fomitopsis pinicola were often present on trees dead for 2 years or more (Wright and Wright 1954). Frequency of decay

in wood chips used for recovering microorganisms tended to increase with years

dead, as expected, for both tree species (tables 4 and 5). Frequency of decay in

wood chips tended to decrease from stump to tree top and toward the center of a log.

There was a higher frequency of decayed wood chips in grand fir than in Douglas-fir

at 0, 3, and 4 years dead, which differed from our earlier finding that Douglas-fir had

more sap rot than did grand fir.

Only four wood samples contained insects, and these were two samples with larvae

of Buprestids in Douglas-fir and two samples with larvae of Cerambycids in grand fir.

Wright and Harvey (1967) also report only minor damage from wood borers for about

the first five years. They also report, however, that the sapwood of Douglas-fir was

extensively decayed in their west-side study by year 5.

Volume Recovery The volume of product that can be produced from standing timber is impacted by

losses in the felling and yarding process, losses from existing defect and defect associated with the death of the trees, and losses associated with turning round logs into

rectangular lumber. The following sections will provide information on these three

aspects for both the live and dead samples.

Table 4— Percentage of scaling defect by defect type and deterioration class

for live and dead Douglas-fir and grand fir logs

Cubic scaling deductions

Species and

deterioration class Cull logs Existing defect Sap rot Weather check

Percent

Douglas-fir:

Live 1.5 4 0 0

1-year dead 3 3 6 1

2-year dead 10 4 13 3

3-year dead 23 4 27 4

4-year dead 21 4 20 5

Grand fir:

Live 5 4 0 0

1-year dead 8 5 10 3

3-year dead 43 6 18 6

4-year dead 39 3 21 5

13
Table 5—Bias and accuracy results for evaluation of the effectiveness of cubic

scaling rules

Number of Average Average

Defect and species logs gross volume Bias Accuracy biasa

−−− Cubic feet −−− Percent

Noncull logs:

Sap rot—

Douglas-fir 161 15.4 1.1 2.2 7.1

Grand fir 68 14.8 2.6 3.8 17.6

Weather check—

Douglas-fir 45 9.2 .2 1.2 2.2

Grand fir 22 10.0 .8 1.6 8.0

Multiple defects—

Douglas-fir 218 19.5 1.1 2.9 5.6

Grand fir 133 22.2 1.9 3.5 8.6

Cull logs

Sap rot—

Douglas-fir 31 5.9 1.3 1.4 22.0

Grand fir 43 9.3 2.0 3.0 21.5

Weather check—

Douglas-fir 10 3.5 .7 .9 20.0

Grand fir 12 4.3 1.3 1.6 30.2

Multiple defects—

Douglas-fir 49 11.7 1.4 3.4 12.0

Grand fir 56 16.5 6.4 10.1 38.8

a Average bias expressed as a percentage of log volume.

14
Breakage during falling and skidding generally increases in dead timber. Breakage in

the live samples was less than 0.5 percent of the gross volume of the trees, based on

measurements taken after felling. The breakage and amount of wood too defective to

remove from the woods was about 2.5 percent in dead Douglas-fir and 3.8 percent in

dead grand fir. These percentages did not change significantly as time since death increased, and they reflect the logging conditions (flat ground) and harvesting systems

(ground-based equipment) used for this study.

Estimated losses from existing defects in the live sample were roughly 4 percent for

both Douglas-fir and grand fir. In both species, the primary cause of volume loss

because of death was sap rot and weather checks. Most sap rot occurred on the

lower logs, while in the upper portions of the boles there was extensive loss due to

weather checking caused by drying. Figure 1 shows the relation between log size and

cubic scaling defect percentage for weather check. No relation with diameter was

found for the other defects. Table 4 shows the percentage of logs culled and the estimated amounts of cubic scaling defect from the noncull portion of the sample. The

existing defect was fairly consistent throughout the sample. There are two reasons

for the differences in sap rot percentages between the previous section and this one:

(1) one is based on trees and the other on logs; and (2) one was a more precise

measurement of diameter affected, and the other is based on scaling rules designed

to estimate the amount of volume available to produce lumber.

The analysis of the relation between the log scaling deduction and the lumber loss

showed that defect estimation was reasonably unbiased and accurate (table 5). No

difference in bias and accuracy was found among the deterioration classes, so the

results were combined. Compared to previous tests of defect (Cahill and Cegelka

1989), the results of this study showed about half the bias for the weather check and

the soft rot. In general, the deductions seem to be effective in predicting the loss in

lumber volume with the exception of the sap rot deductions for grand fir. The scalers

commented that this deduction was particularly difficult because the defect was in

scattered pockets rather than throughout the entire sapwood. A positive bias indicates

an overestimation of the defect; the estimate for grand fir was generally more biased

than that for Douglas-fir for all defects.

Cull logs present a special category of logs that are judged by scalers to have less

than one-third of the volume available for lumber production, and they may or may

not contain merchantable volume (USDA 1985). In this study, some cull logs were left

in the woods because they were too rotten to load on the truck, some were brought

to the mill yard but not sawn because they were too rotten to hold together on the

headrig, and some were sawn and produced lumber volume. Almost twice as many

grand fir logs were culled compared to Douglas-fir (table 4), and roughly half of the

culls for each species were sawn in the mill. The defect deductions for the cull logs

were very biased (table 5), which shows that more lumber is recovered from the logs

than the net scale predicts; however, this is just an evaluation of how much lumber is

recovered and does not take into consideration the quality or value of that lumber.

15
Cubic recovery percent—The most accurate way of measuring product volume

recovered from a log is CR% because it uses cubic volume for both lumber and log.

Analysis of CR% was done by using gross cubic scale, by deterioration class, with

cull logs analyzed as a separate sample. Results of the covariance analysis showed

no significant differences between the two samples of live logs by species and the

1-year-dead Douglas-fir sample. No significant difference was found between the

dead samples for grand fir and the 2-year-dead sample of Douglas-fir. Finally, no

difference was found between the 3- and 4-year-dead Douglas-fir samples. Therefore

the results will be presented for the following deterioration classes:

Class Species Years since death

Live Douglas-fir Live

Grand fir Live

Douglas-fir 1 year

GFVol Grand fir 1 year

Grand fir 3 years

Grand fir 4 years

Douglas-fir 2 years

DFVol Douglas-fir 3 years

Douglas-fir 4 years

0 5 10 15 20 25 30

0

2

4

6

8

10

12

Log small-end diameter (inches)

Percent defect

1-year dead

2-year dead

3-year dead

4-year dead

Figure 1—Log scaling deductions for weather check are shown for the Douglas-fir sample. Weather

checks are found primarily in the upper portions of the trees. The volume deducted decreases as log

diameter increases, and increases with time since death.

16
The change in recovery volume that takes place as a tree changes from live to dead

is clearly illustrated in figure 2. Regression equations and statistics are found in

table 6. The volume of lumber recovered is different between samples of dead grand

fir and Douglas-fir. With Douglas-fir, very little volume is lost in the first year after

death, so the 1-year-dead sample was combined with the live sample. Two-year-dead

Douglas-fir recovered about 8 percent less volume than live and 1-year dead, the

same as all classes of grand fir dead. Three-and four-year dead, combined, lost

another 7 percent volume. Cubic recovery percent of cull logs is also shown in

figure 2. The Douglas-fir cull logs recovered 34 percent of the log volume as lumber,

but the grand fir cull logs larger than 10 inches recovered more lumber than the 3-

and 4-year-dead Douglas-fir and only slightly less volume than the dead samples of

grand fir. This follows the earlier finding that the amount of defect in the grand fir is

difficult to estimate, and in this study, the deductions were not well correlated with the

actual volume of lumber lost. It is important to remember that this reflects only the

amount of lumber that is produced and not the quality of that lumber.

Lumber recovery factor—Lumber recovery factor (LRF) is a measure of the number

of board feet of lumber that can be produced from a cubic foot of log. As with CR%,

it is based on the gross cubic-foot scale volume of the logs. In this study, the ratio between the board foot of lumber and the cubic foot of lumber (BF/CF) was consistently

11.8. It is therefore possible to convert the CR% given in figure 2 directly into LRF as

follows: CR% BF/CF of lumber = LRF. For example, a 10-inch live log has a CR%

of 54.8 percent, which is multiplied by the BF/CF of 11.8, resulting in an LRF of 6.47.

Overrun—Overrun is the term for the percentage of lumber recovered by a sawmill in

relation to the log scaler’s estimated amount of volume (net Scribner scale). Scribner

scale does not take taper into consideration and typically is highly inaccurate in estimating net scale when used for measurement of dead timber (Snellgrove and Cahill

1980). No significant relation was found between overrun and small-end diameter, so

averages were calculated for each of the combined classes as follows: average overrun for the Douglas-fir live, Douglas-fir 1-year dead, and grand fir live samples was

0 5 10 15 20 25 30

10

20

30

40

50

60

70

80

Log small-end diameter (inches)

Percent

Live

Grand fir Volume

Douglas-fir Volume

Grand fir Cull

Douglas-fir Cull

Figure 2—Cubic recovery percent is greatest for the live sample and is reduced by 10 to 15

percent for grand fir and Douglas-fir samples. Cubic recovery percent is lowest for cull logs

from all samples. Regression equations and statistics are found in table 6.

17
140 percent; average overrun for the combined 2- to 4-year dead Douglas-fir samples

was 166 percent, and 185 percent for combined grand fir dead samples; average

overrun for the cull samples was 203 percent for Douglas-fir and 506 percent for

grand fir. It is apparent that the scaling rules again over-deducted for the defects,

thereby causing the overrun to increase in the dead samples, especially for grand fir.

Value Recovery Dollars per thousand lumber tally—Dollars per thousand lumber tally ($/MLT) is the

most accurate measure of the inherent wood quality, because it is based only on the

lumber that is produced and does not include estimates of defect. It was used to test

the inland Douglas-fir saw-log grades to see if they segregate the value of the resource. Analysis of $/MLT showed no statistical difference among the grades; thus,

log grades were not used in further analysis. Dollars per thousand lumber tally was

then used to test for differences among deterioration classes. Similar to the CR%

results, no difference was detected between the live samples and the 1-year dead

Douglas-fir sample, and no difference was found among the samples of dead grand

fir. A slightly different result was found with the dead Douglas-fir samples, in that the

2-year dead was found to not be different from the 3- and 4-year-dead samples. Two

additional deterioration classes therefore were established: GFVal, which includes all

years of grand-fir dead; and DFVal, which includes years 2 through 4 of Douglas-fir

dead. Regression equations and statistics are found in table 6.

Table 6— Regression equations and statistics for estimates of volume recovery

Dependent variable Equation R2 MSEa

Cubic recovery percent of rough green lumber volume

Live 76.18-212.71/D 0.4544 10.45

GFVol 68.01-218.50/D 0.2912 10.55

DFVol 54.64-138.39/D 0.1900 10.10

Douglas-fir cull 40.59-64.00/D 0.0403 14.52

Grand fir cull 45.63 (mean) 0.3165 12.95

Dollars/1000 lumber tally

Live 328.62+6.76*D 0.2006 64.63

GFVal 237.68+10.79*D 0.3340 54.92

DFVal 279.75+5.05*D 0.0900 66.68

Douglas-fir cull 279.97 (mean) 0.0000 80.55

Grand fir cull 342.49-0.84*D 0.0000 59.03

Dollars/100 cubic feet of gross log volume

Live 417.79-1454.97/D 0.3988 80.09

GFVal 396.05-2018.79/D 0.4440 60.56

DFVal 253.38-803.23/D 0.1794 61.40

Douglas-fir cull 145.51-306.79/D 0.0576 57.72

Grand fir cull 179.60 (mean) 0.2202 60.55

aMSE=Total mean squared error of the regression model.

18
Dollars per thousand lumber tally increased with increasing diameter (fig. 3) because

there was more opportunity to recover higher grade lumber and also larger size lumber from larger logs. Douglas-fir live and 1-year-dead logs were worth about $70 per

thousand more than 2-, 3-, and 4- year-dead logs for all diameters. The grand fir

dead sample produced lumber that was $100 less valuable than the live sample for

logs with 5-inch diameters compared to logs with relatively no difference from the live

in the larger diameters. Average lumber value of the cull logs reflected the large increase in Economy and Utility lumber that is produced from these logs.

Percentage of lumber volume by lumber grade—Percentage of lumber volume

produced by lumber grade can help to explain changes in value recovery over diameter and deterioration class. Lumber grade recovery is presented in figure 4 and

table 7 for the combinations of deterioration classes that were determined by analysis

of $/MLT. In both species, Select Structural grades were produced in low volume

(less than 10 percent). For Douglas-fir there was a 3-percent decrease in production

of Select Structural from live trees compared to the 2-to 4-year-dead class. Production of Standard lumber dropped 17 percent when trees left standing for 2 years were

compared to live trees. Production of Utility grade lumber in the 2-year and older

dead class was more than double that from live trees. Grand fir grade recovery was

more dramatically affected by death of the tree. As shown in figure 4, Construction

grade lumber production falls off drastically after the tree dies. The amount of Construction grade lumber available from all years of dead was less than one-half that

from live trees. Utility grades showed an increase, jumping from 14 to 24 percent

when sawn from 1-year-dead timber vs. live. The volume recovered from Economy

was relatively minor but followed the trend of Utility to increase in volume share after

the tree was dead a few years. Cull logs of both species produced very little Select

Structural or Construction grade material. The Douglas-fir cull sample produced

40 percent Economy and 27 percent Utility lumber. The grand fir cull sample, on

the other hand, produced less than 20 percent Economy and about 40 percent Utility.

0 5 10 15 20 25 30

250

300

350

400

450

500

550

Log small-end diameter (inches)

Dollars per 1000 lumber tally

Grand fir Value

Doudlas-fir Value

Grand fir Cull

Douglas-fir Cull

Live

Figure 3—Dollars per thousand lumber tally increased with increasing diameter because there was more

opportunity to recover higher grade lumber and larger size lumber from larger logs. Average lumber value

of the cull logs reflects the increased volumes of Economy and Utility grade lumber produced.

19
0

20

40

60

80

100

120

Diameter

Percent

4 8 12 16 20 24

Economy

Utility

Standard

Construction

Select Structural

Live

0

20

40

60

80

100

120

Diameter

Percent

4 8 12 16 20 24

Douglas-fir Value

0

20

40

60

80

100

120

Diameter

Percent

4 8 12 16 20 24

Grand fir Value

0

20

40

60

80

100

120

Diameter

Percent

4 8 12 16 20 24

Douglas-fir Cull

0

20

40

60

80

100

120

Diameter

Percent

4 8 12 16 20 24

Grand fir Cull

A

B C

D E

Figure 4—Percentage of lumber volume by lumber grade illustrates the differences in value among the

live, dead, and cull samples of logs. A. Production of Construction and Select Structural grade lumber

was highest for the live log sample. B. Volume of Utility grade lumber doubles and Construction grade

decreases in the Douglas-fir dead sample (DF Value) compared with the live sample. C. The volume of

Select Structural and Construction decreased by 50 percent and volume of Utility doubled in the grand fir

dead sample (GF Value) compared with the live sample. D. Sixty to ninety percent of the volume of the

Douglas-fir cull log sample was graded as Utility or Economy. E. The grand fir cull log sample produced

much less Economy and Utility than did the Douglas-fir cull log sample but significantly more than the

grand fir dead sample.

20
Dollars per hundred cubic feet—Dollars per hundred cubic feet of gross scale is an

estimate of the value of the log, including the defect. For the combined live samples

and the 1-year-dead Douglas-fir sample, the $/CCF increased rapidly in the smaller

diameters and then began to level off in the larger diameters (fig. 5). This correlates

with the increased output of construction and higher grade dimension products. In the

2- to 4-year-dead Douglas-fir class, the value increased more gradually with

increases in log size. Economy and Utility production stayed about the same with

increasing diameter, Standard grade lumber decreased slightly, and Construction and

Select Structural grade increased, but only slightly. The combined effect was a very

gradual increase in value as log diameter increased in the 2- to 4-year-dead class.

The grand fir combined dead sample increased in value at the same rate as the live

samples when diameter increased. The cull log samples had lower values than any

of the live or dead classes. The Douglas-fir cull sample was considerably lower in

value than any other sample, but the grand fir cull was closer to the value of the dead

Douglas-fir class. This reflected the higher volume recovery but lower quality of the

lumber for grand fir.

Conclusions The amount of sap rot, caused principally by Cryptoporus volvatus, was relatively low

in Douglas-fir and grand fir, especially when compared to west-side decay rates

(Wright and Wright 1954). The amount of checking was very high, probably due to

several years of drought after tree death. Sap rot and especially checking increased

with time since tree death. Few insects were associated with defective wood, probably because of the relatively dry condition of the wood.

Table 7—Percentage of lumber volume by species, lumber grade group, and

years since death

Years dead

Species and Cull

lumber grade group Live 1 2 3 4 logs

Percent

Douglas-fir:

Select structural 5 4 2 2 2 0

Construction 20 15 13 12 13 2

Standard 55 46 38 37 34 30

Utility 16 30 37 38 33 27

Economy 4 5 10 12 17 40

Grand fir:

Select structural 8 4 — 1 3 0

Construction 34 17 — 16 11 7

Standard 43 49 — 50 46 39

Utility 14 24 — 29 34 42

Economy 0 6 — 5 7 12

21
Losses associated with breakage and handling were minor, ranging from 0.5 percent

to 3.8 percent for all samples. Existing defect averaged 4 percent for all samples.

Weather check increased from 1 to 5 percent and sap rot increased from 6 to 20

percent as time since death increased from 1 to 4 years. Scaling deductions worked

fairly well at predicting the lumber volume loss due to defect, except in the grand fir

dead samples where the deductions were too severe.

Cubic recovery percent showed no difference between the live samples and the

1-year-dead Douglas-fir sample, so they were combined. The other dead samples

were combined into a class for all grand fir dead and Douglas-fir 2-year dead and a

class for the Douglas-fir 3- and 4-year dead. There was an 8-percent loss in CR%

between the live and grand fir dead classes and a 15-percent loss in CR% between

the live and Douglas-fir 3-and 4-year-dead classes.

Analysis of $/MLT and $/CCF showed no difference among the live and 1-year dead

Douglas-fir samples. The dead classes shifted slightly with all the Douglas-fir dead

(years 2 to 4) being combined and all the grand fir classes being combined. Average

log value decreased about $60 from the live class to the grand fir dead class and

another $60 for the Douglas-fir dead. Contrary to popular belief, the grand fir did not

deteriorate as fast as the Douglas-fir or lose as much value as expected.

Cull logs ranged from 3 to 40 percent of the samples as age since death increased.

Only half of these logs were sound enough to process into lumber, but those logs

recovered more volume than the scalers anticipated. The Douglas-fir cull logs recovered only 34 percent of the gross volume as lumber, but the grand fir cull sample

recovered more lumber than the Douglas-fir 3-and 4-year-dead class and only slightly

0 5 10 15 20 25 30

0

100

200

300

400

Log small-end diameter (inches)

Dollars per 100 cubic feet

Grand fir Value

Douglas-fir Value

Grand fir Cull

Douglas-fir Cull

Live

Figure 5—Dollars per hundred cubic feet of gross scale is an estimate of the value of the log, including

the defect. The grand fir dead sample was $70 per hundred cubic feet less in value than the live

sample. The Douglas-fir dead sample was $60 per hundred cubic feet less in value than the grand fir

dead sample. Dollars per hundred cubic feet is lowest for cull logs from all samples.

22
less than the grand fir dead sample. The lumber that was produced was largely comprised of Economy and Utility grade. The combination of the high volume recovery

and low value recovery resulted in log values for the grand fir culls that were only

slightly less than those for the Douglas-fir dead class, but the Douglas-fir culls were

worth considerably less than any other sample.

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Oregon. Res. Note PNW-RN-489. Portland, OR: U.S. Department of Agriculture,

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Furniss, R.L.; Carolin, V.M. 1977. Western forest insects. Misc. Publ. 1339.

Washington, DC: U.S. Department of Agriculture, Forest Service. 654 p.

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Parry, Dean L.; Filip, Gregory M.; Willits, Susan A.; Parks, Catherine G. 1996.

Lumber recovery and deterioration of beetle-killed Douglas-fir and grand fir in the

Blue Mountains of eastern Oregon. Gen. Tech. Rep. PNW-GTR-376. Portland, OR:

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

Station. 24 p.

The purpose of this study was to determine the effect of time since death over a

4-year period on the amount of usable product volume and value, and to determine

the species of fungi associated with wood deterioration in the stems of Douglas-fir and

grand fir trees killed by bark beetles in northeastern Oregon. Two-year- dead

Douglas-fir recovered about 8 percent less lumber volume than live and 1-year dead

Douglas-fir and all classes of dead grand fir. Three- and four-year dead Douglas-fir

combined lost another 7 percent in lumber volume. Average lumber value (dollars per

thousand lumber tally) and average log value (dollars per hundred cubic feet) analysis

showed no difference among the live and 1-year-dead Douglas-fir samples. Average

log value decreased about $60 from the live class to the grand fir dead class and

another $60 for the Douglas-fir dead. Contrary to popular belief, the grand fir did not

deteriorate as fast as the Douglas-fir or lose as much value as expected.

Keywords: Douglas-fir, Pseudotsuga menziesii, grand fir, Abies grandis, lumber

recovery, utilization, dead timber, western spruce budworm, Choristoneura

occidentalis Freeman, Douglas-fir beetle, Dendroctonus pseudotsugae, fir engraver,

Cryptoporus volvatus, Trichaptum (Polyporus) abieinum, Fomitopsis pinicola.

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