United States 

Department of 

Agriculture 

Forest Service 

Northeastern Forest 

Experiment Station 

Research Paper NE-692 

Closure of Logging Wounds - After 10 Years- - 

H. Clay Smith 

Gary W. Miller 

Thomas M. Schuler 
Abstract 

Closure of logging wounds on 96 sample trees was evaluated after 2,5, and 10 

years for Appalachian hardwood trees in north-central West Virginia. For yellowpoplar, northern red oak, black cherry, and white oak, many small wounds, 1 to 50 

square inches in size, closed between 5 and 10 years after logging. For larger 

wounds, 50 to 200 square inches, it appears that many of these wounds may not 

close for at least 15 or perhaps 20 years after logging. Recommendations are 

provided to minimize logging wounds on residual trees in partially cut stands. 

The Authors 

H. CLAY SMITH (retired) was project leader and principal silviculturist at the 

Northeastern Forest Experiment Station's Timber and Watershed Laboratory, 

Parsons, West Virginia. He received B.S. and M.S. degrees from West Virginia 

and Purdue Universities, and joined the Northeastern Forest Experiment Station in 

1962. 

GARY W. MILLER is a research forester with the Timber and Watershed 

Laboratory project on managing resources in central Appalachian hardwood 

forests. He received B.S. and M.S. degrees from West Virginia University and a 

Ph.D. degree from Virginia Polytechnic Institute and State University. 

THOMAS M. SCHULER, research forester with the Northeastern Forest 

Experiment Station's Timber and Watershed Laboratory at Parsons, West Virginia, 

received a B.S. degree in forestry from Purdue University and an M.S. degree in 

silviculture from Colorado State University. He joined the USDA Forest Service in 

1992. 

Manuscript received for publication .24 March 1994 

USDA FOREST SERVICE 

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September 1994 
Introduction 

Damage to residual trees during thinning operations and 

partial regeneration cuts is a major concern of forest 

managers. Residual trees are damaged by felling trees 

and by winching and skidding trees to a log landing. Trees 

with extensive damage such as severely broken tops or 

trees that have been uprooted likely will be salvaged when 

the damage occurs. Less severe damage such as bark 

removal that exposes sapwood also is frequent. Sapwood 

wounds pose no immediate threat to the tree but increase 

the likelihood of attack by insects or diseases. 

In this paper we discuss the time required for closure of 

bark-related (exposed sapwood) wounds incurred during 

logging. This information can be used by forest managers 

to estimate the time required for a logging wound to close. 

Knowing how long it takes for a wound to close (callus 

over) will aid in deciding whether to salvage a damaged 

tree or leave it in the stand until the next entry period. 

Nyland and Gabriel (1971) indicated that about 80 percent 

of skidding injuries to residual trees entail bark removal or 

abrasion to the butt log. In this New York study, major 

injuries from felling were about twice those from winching/ 

skidding even though about 70 percent of the standing 

trees adjacent to a skidroad were damaged from treelength skidding. 

Size of the exposed sapwood wound is important as it 

relates to decay and closure. Residual trees are damaged 

primarily during felling or skidding. Damage is largely 

confined to saplings and poles, though sawtimber trees 

also are wounded (Lamson and Miller 1983). Research 

has shown that exposed sapwood wounds of more than 

100 square inches are likely to develop decay (Hesterberg 

1957; Lavallee and Lortie 1968). Lamson and Miller 

(1 983) reported results from stands of pole- and small 

sawtimber-size trees logged with a rubber-tired skidder on 

relatively gentle to flat slopes. hogging damage to the 

residual stand increased with intensity of thinning. About 7, 

13, and 22 percent of the residual dominant-codominant 

trees had exposed sapwood wounds of at least 100 square 

inches when the area was logged to a residual stocking of 

75, 60, and 45 percent, respectively. 

Butin and Shigo (1981) indicated another concern related 

to shakes and logging wounds. Shakes can result from 

logging wounds and pruning of branches or stump sprouts. 

In many cases, if the trees are not injured during logging or 

branch stubs are not present, stress factors that cause 

shakes, such as fast growth, vigor, and frost, have little or 

no influence on the development of the crack. 

Study Location 

The study areas were on the Fernow Experimental Forest 

and the Monongahela National Forest in north-central West 

Virginia near Parsons, West Virginia. Trees were selected 

on good sites with a site index of 70 and above for 

northern red oaks. Cove hardwoods were the major 

species on these sites, including northern red oak, yellowpoplar, black cherry, white oak, sugar maple, beech, and 

basswood. Study trees were second-growth Appalachian 

hardwoods in the codominant crown class. These trees 

were 75 to 80 years old at time of logging and were 

released to a free-to-grow crown position (released on all 

four sides of the crown). Annual precipitation on the study 

area averaged 55 to 60 inches; there are 120 to 640 frostfree days during the growing season. Soils were primarily 

of sandstone origin with a depth to bedrock of 4 to 5 feet. 

Soil pH was near 5.0. Topography was mixed, with steep 

(slopes of 50 to 60 percent), moderate (20 to 25 percent), 

and flat (0 to 10 percent) sites. 

Methods 

All trees were harvested with conventional ground-skidding 

equipment (rubber-tired skidder or crawler tractor with an 

arch). Skidroads were spaced 150 to 250 feet apart 

depending on the steepness of the topography. Trees 

were skidded tree length to a log landing. 

Exposed sapwood (skins) was identified and measured on 

mature sawtimber-size trees periodically at 2, 5, and 10 

years after logging. The surface area of logging wounds 

was calculated based on rectangles. Wound length and 

width was measured to the nearest inch; these 

measurements always were rounded to provide 

conservative estimates of wound size. 

Species selected for samples were trees damaged during 

logging (no effort was made to deliberately damage a tree). 

Samples were available primarily from northern red oak, 

white oak, and yellow-poplar. A few samples were 

available from black cherry, basswood, and sugar maple. 

Often, a single tree had wounds of more than one size so 

there is a difference in number of wounds per trees 

sampled. In all, 96 damaged trees were sampled 2 years 

after log wounding occurred. These same trees were 

reexamined at the 5- and 10-year measurement periods. 

Due to the small number of samples per species, the 

information presented here is preliminary. 

Results 

The number of study trees with exposed sapwood wounds 

at different periods is summarized by species in Table 1. 

Information on wound closure by size is shown in Tables 2 

and 3 (Figs. 1-2). Data were recorded at the 2-, 5-, and 

10-year periods. Some logging wounds are not visible 

immediately after logging. For example, some trees were 

bumped with logs during winching or skidding but the bark 

was not removed. However, after 2 years, much of the 

bark fell off "hidden" wounds, allowing a better estimate of 

logging damage. None of these wounds observed 

immediately after logging had closed during the 

subsequent 2-year period. 

For northern red oak, 30 trees were examined initially; 28 

white oak and 22 yellow-poplar were examined. The 

number of trees with wounds that did not close or callus 

over is indicated at the 5- and 10-year period after logging 

(Table 1). No northern red oak trees had closed wounds 
Figure 1 .--Exposed northern red oak sapwood wound due to damage from log skidding. 

Figure 2.Sapwood wound in northern red oak that closed during the 10-year period. 
after 2 years, 5 trees had closed wounds after 5 years, and 

18 trees had closed wounds after 10 years. Yellow-poplar 

had the greatest proportion of trees with closed wounds--1 8 

of 22 wounds were ciosed after 10 years. 

Table 1.--Number of sample trees with open exposed 

sapwood wounds due to logginga 

Years after woundina occurred 

Species 

N. red oak 

White oak 

Yellow-poplar 

Black cherry 

Chestnut oak 

Basswood 

Total 

Two Five Ten 

Number of trees 

30 25 12 

28 25 18 

22 14 4 

8 6 5 

5 4 4 

3 2 0 

96 76 43 

aBecause several trees had more than one wound, 

tree-wound data not additive. 

Of the 45 wounds that were 1 to 50 square inches, 26 

closed during the 5-year period after logging (Table 2). 

Yellow-poplar had the most closed wounds with 10 while 

red oak had 7. One wound (yellow-poplar) in the 51- to 

100-square-inch class closed during the 5-year interval. 

Between 6 and 10 years after logging, 17 additional 

wounds in the 1- to 50-square-inch category closed. Thus, 

for the species and conditions evaluated in this study, one 

could expect most of the wounds that were 1 to 50 square 

inches to close after 10 years (Table 2). When wounds of 

all sizes are considered, 59 percent (58 of 99) had closed 

after 10 years. Most of the closed wounds (43) were in the 

1- to 50-square-inch size class (Table 2). For wounds 

larger than 50 square inches, 28 percent (15 of 54) had 

closed 10 years after logging damage. 

At the end of the 10-year period, the exposed sapwood 

wounds that did not close were summarized (Table 3). 

Percent closure was indicated for each wound size class. 

Of the original 96 trees that were wounded during logging, 

43 still had open wounds after 10 years. However, only 

one species (black cherry) had two open wounds in the 

1 - to 50-square-inch category that did not close. These 

wounds were not expected to dose for several years since 

each averaged only 32 percent closure after 10 years. In 

general, for the 51 - to 200-square-inch class, most of the 

wounds (21) averaged 74 percent closure for red oak, 

white oak, yellow-poplar, black cherry, and chestnut oak. If 

this trend continues, several of these wounds should close 

during the next 5-year period. Of the wounds larger than 

200 square inches, 21 averaged slightly more than 50 

percent closure. 

Discussion and Summary 

Logging damage resulting in exposed sapwood is a key 

factor in lower butt-log quality. These wounds provide a 

source of entry for insects and diseases and also are a 

source of ring shakes and cracks. Although sampling for 

the presence of rot in a closed wound was not done, 

superficial rot characteristics (fungal fruiting bodies) were 

not present on any of the closed wounds. However, wood 

discoloration and perhaps decay will occur, and volume 

might be reduced. This discoloration will not result in a 

reduction of tree grade, but there will be some value loss 

due to lower lumber grade. 

The results of this study show that small wounds of 1 to 50 

square inches should close 5 to 10 years after logging. It 

appears that most of the wounds of 50 to 200 square 

inches will close 15 to 20 years after logging. Currently, 

average closure of these wounds is 75 percent or more. 

Study trees were large, maturing codominant stems that 

were released to a free-to-grow crown position. These 

large trees were growing between 2.5 and 3.5 inches in 

d.b.h. per decade and averaged 17 inches at the time of 

initial logging (Smith and Miller 1991). Based on species 

d.b.h. growth, faster growing species such as yellow-poplar 

and northern red oak have the most rapid closure of small 

wounds. Many small sapwood wounds on red oak, white 

oak, and yellow-poplar closed within 10 years after logging. 

Within the first 10 years, 18 (100 percent) red oak wounds 

and 13 (100 percent) yellow-poplar wounds in the I- to 

50-square-inch class had closed. 

When forest stands receive partial cuts, a major effort 

should be taken to minimize logging damage to the 

residual stand. The key to reducing exposed sapwood 

during logging is effective communication among the tree 

feller, equipment operator, and choker setter. They must 

be aware of the problems that could result from "barking" 

the trees. In general, small exposed sapwood wounds at 

or below the base of the butt log will not create major 

problems with respect to tree or log grade or quality. 

However, larger wounds extending into the base of the butt 

log could develop rot. This could mean a loss in value for 

wood products or a gain in "value" if development of cavity 

trees for wildlife is an objective. If dollar values are 

important to the landowner, a short cutting cycle, every 10 

to 20 years on productive sites, is advisable. Short cutting 

cycles allow the landowner to select trees at risk of dying 

or about to have a major loss in value. The landowner 

could improve the stand aesthetically, too. Conversely, 

with more frequent cutting cycles, there is a higher 

possibility for increased damage to residual trees. 

Wood-rotting fungi do not always develop when trees are 

damaged during logging. Baxter and Hesterberg (1958) 

reported that fungi associated with decay in logging 

wounds were increasing in 10- and 20-year-old sugar 

maple logging scars. Hesterberg (1957) indicated that 

exposed sapwood wounds of at least 150 square inches in 

sugar maple have an even chance (50 percent) of 

developing decay within 20 years. There was an overlap 

for these data as there is an 80-percent chance that 

wounds of 130 to 200 square inches will develop decay 

within 20 years. Lavallee and Lortie (1968) observed 

similar effects with the removal of only 90 square inches of 

bark from yellow birch trees. 
Table 2.--Exposed sapwood logging wounds that callused (closed) 5 to 10 

years after logging 

Species Number of Number closed Number closed 

wounds at 5 years at 10 years 

I to 50 id 

N. red oak 18 7 (39)" 18 (1 00) 

White oak 6 4 (67) 6 (100) 

Yellow-poplar 13 10 (77) 1 3 (1 00) 

Black cherry 4 2 (50) 2 (50) 

Chestnut oak 1 1 (1 00) 1 (1 00) 

Basswood 3 2 (67) 3 (1 00) 

Total 45 26 (58) 43 (96) 

51 to 100irr? 

N. red oak 3 0 1 (33) 

White oak 3 0 1 (33) 

Yellow-poplar 5 1 (20) 

-- 3 (60) 

Black cherry 0 -- 

Chestnut oak 1 0 0 

Basswood 0 -- -- 

Total 

N. red oak 

White oak 

Yellow-poplar 

Black cherry 

Chestnut oak 

Basswood 

Total 

N. red oak 

White oak 

Yellow-poplar 

Black cherry 

Chestnut oak 

Basswood 

Total 

- -- -- 

aPercent in parentheses. 

Table 3.-Number of exposed sapwood logging wounds that did not callus over (close) during 

the 10-year period after logging 

Sauare inches of ex~osed S~DWOO~ 

Species 1-50 51 -1 00 101-150 151-200 201 + 

aAverage percent reduction in size of wounds in parentheses. 
The following are some suggestions to reduce logging 

damage: 

@ Plan and lay out skidroads and log landings carefully 

for the most efficient access with minimum disturbance to 

the residual stand and turning of the log load. 

@ Consider a maximum winching or skidding tree length, 

for example, 33 feet. 

@ Leave "fender trees" or topped trees along the skidroad 

to keep the log load in the skidroad or to provide a pivot or 

turning point for logs. 

@ When the opportunity is available, mark trees to leave 

rather than trees to cut. Aho and others (1983) showed 

that this marking technique can reduce logging wounds 

because loggers are more aware of the location of the crop 

trees. 

@ Protect crop trees from skidding wounds by leaving 

some poles or small sawlog trees near crop trees to serve 

as bumper trees. 

@ When there is a choice, avoid logging during spring 

when the sap is up and the bark is easier to remove from 

the tree (Deitschman and Herrick 1957). 

@ When damage is impossible to prevent during winching 

or skidding, consider damaging a less desirable versus 

more desirable species (following landowner objectives). 

@ When possible, use smaller logging equipment during 

partial cuts. Also, there is less damage (wounding) from 

crawler tractors than from skidders during skidding 

operations (Nyland and Gabriel 1972). 

@ Use directional felling and winching to minimize logging 

damage. Anticipate when damage might occur and try to 

avoid ii. Fell trees away from more desirable trees and 

position trees for more effective winching and skidding with 

a minimum of turning (Nyland 1986). 

@ Increase supervision of logging crew to minimize 

damage. Communicate concerns related to numbers and 

types of logging damage and the potential value that could 

be lost. Discuss the significance (value) of the butt log 

(which incurs the majority of logging damage). 

@ Provide training in log grading for members of the 

logging crew, particularly the feller and bucker. 

Provide incentives for the logger to reduce damage 

and impose penalties for unacceptable damage to the 

residual stand. 

@ Remove forks and large branches from felled trees 

before winching or skidding. 

@ Remove previously damaged trees during subsequent 

thinnings. If trees are harvested within 10 years after 

wounding, losses should be minimal--see Ohman (1 970) 

for sugar maple and yellow birch and Lamson et al. (1984) 

for black cherry and red maple. 

As the value of the timber stand increases, so does the 

Importance of minimizing logging damage to the residual 

stand. The landowner also needs to be aware there is a 

cost associated with "logging carefully" and that he or she 

must share this cost. The company or logger that offers 

the highest price for a timber sale is not always the best 

"environmental logger." Likewise, prospective timber 

buyers need to know both the legal requirements and the 

landowner's requirements with respect to the residual 

stand. A contract is recommended. Foresters need to 

inform the logger and landowner of the need to minimize 

damage to residual trees in Appalachian hardwood stands 

or any other forest stand. 

Aho, Paul E.; Fiddler, Gary; Srago, Mike. 1983. hogging 

damage in thinned young-growth true fir stands in 

California and recommendations for prevention. 

Res. Pap. PNW-304. Portland, OR: U.S. Department of 

Agriculture, Forest Service, Pacific Northwest Forest 

and Range Experiment Station. 8 p. 

Baxter, Don V.; Hesterberg, Gene A. 1958. Fungi 

associated with decay in sugar maple following 

logging injury. Tech. Note 528. St. Paul, MN: US. 

Department of Agriculture, Forest Service, Lake States 

Forest Experiment Station. 2 p. 

Butin, Heinz; Shigo, Alex L. 1981. Radial shakes and 

"frost cracks" in living oak trees. Res. Pap. NE-478. 

Broomall, PA: U.S. Department of Agriculture, Forest 

Service, Northeastern Forest Experiment Station; 21 p. 

Deitschman, Glenn H.; Herrick, David E. 1957. Logging 

injury in Central States upland hardwoods. Journal 

of Forestry. 55(4): 273-277. 

Hesterberg, G. A. 1957. Deterioration of sugar maple 

following logging damage. Stn. Pap. 51. St. Paul, 

MN: U.S. Department of Agriculture, Forest Service, 

Lake States Forest Experiment Station. 58 p. 

Lamson, Neil I.; Miller, Gary W. 1983. Logging damage 

to dominant and codominant residual stems in 

thinned cherry-maple stands. In: Proceedings, 4th 

central hardwood forest conference; 1982 November 9- 

10; Lexington, KY: University of Kentucky: 32-38. 

Lamson, Neil I.; Smith, H. Clay; Miller, Gary W. 1984. 

Residual stocking not seriously reduced by logging 

damage from thinning of West Virginia cherry-maple 

stands. Res. Pap. NE-541. Radnor, PA: U.S. 

Department of Agriculture, Forest Service, Northeastern 

Forest Experiment Station. 7 p. 

Lavallee, A.; Lortie, M. 1968. Relationships between 

external features and trunk rot in living yellow birch. 

Forestry Chronicle. 44 (2): 5-10. 
Nyland, Raiph D. 1986. Logging damage during 

thinning in even-aged hardwood stands. In: Smith, 

H. Clay; Eye, Maxine C., eds. Workshop proceedings: 

guidelines for managing immature Appalachian 

hardwood stands; I986 May 28-30; Morgantown, WV. 

Morgantown, WV: West Virginia University: 150-1 66, 

Nyland, Ralph D.; Gabriel, William J. 1971. Logging 

damage to partially cut hardwood stands in New 

York state. AFRl Res. Rep. 5. Syracuse, NY State 

University College of Forestry, Applied Forestry 

Research Institute. 78 p. 

Myland, Ralph D.; Gabriel, William J. 1972. Injuries from 

tree-length skidding with rubber-tired versus 

crawler tractors. AFRl Res. Rep. 8. Syracuse, NY: 

State University College of Forestry, Applied Forestry 

Research Institute. 11 p. 

Ohman, John H. 1970. Value loss from skidding 

wounds in sugar maple and yellow birch. Journal of 

Forestry. 68(4): 226-230. 

Smith, H. Ciay; Miller, Gary W. 1991. Releasing 75- to 80- 

year-old Appalachian hardwood sawtimber trees: 

5-year d.b.h. response. In: McCormick, Larry H.; 

Gottschalk, Kurt W., eds. Proceedings, 8th central 

hardwood forest conference; 1991 March 4-6; University 

Park, PA. Gen. Tech. Rep. NE-148. Radnor, PA: U.S. 

Department of Agriculture, Forest Service, Northeastern 

Forest Experiment Station: 403-41 3. 
Smith, H. Clay; Miller, Gary W.; Schuler, Thomas M. 1994. Closure of logging 

wounds after 10 years. Res. Pap. NE-692. Radnor, PA: U.S. Department of 

Agriculture, Forest Service, Nolaheastern Forest Experiment Station. 6 p. 

Closure of logging wounds on 96 sample trees was evaluated after 2, 5, and 10 

years for Appalachian hardwood trees in north-central West Virginia. For 

yellow-poplar, northern red oak, black cherry, and white oak, many small 

wounds, 1 to 50 square inches in size, closed between 5 and 10 years after 

logging. For larger wounds, 50 to 200 square inches, it appears that many of 

these wounds may not close for at least 15 or perhaps 20 years after logging. 

Recommendations are provided to minimize logging wounds on residual trees in 

partially cut stands. 

Keywords: logging wounds, sapwood, wound closure, butt log, quality 

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