- United States 

Department of 

Agriculture of Thinning 

Forest Service on Growth and Potentia Quality NorZheastern Forest 

o Young Wh e Oak Crop Trees 

Research Paper 

NE-539 Martin E. Dale 

David L. Sonderman 
The Authors 

Martin E. Daie, research forester, joined the USDA Forest Service in 1957, 

spe~ializing in forest management and silviculture research at Berea, KentucQ. In 

1973, he received a Ph.0 degree in forest biometry from Iowa State University, 

and was assigned to the Northeastern Forest Experiment Station's research unit at 

Delaware, Ohio. Currently he is specializing in studies of growth and yield of 

managed upland oaks. 

David L. Sonderman, research forest product technologist, received a B.S. 

degree in forestry from West Virginia University in 1962, He joined the 

Northeastern Forest Experiment Station in June 1962, and was a member of the 

staff of the Eastern Softwood Timber Quality Project until June 1972. He is 

currently with the Northeastern Station's project on Management and Utilization 

Atternatives for Nonindustrial Private Forests at Delaware, Ohio. 

Manuscript received for 

publieation 10 June 1983 

Abstract 

Relative change in several types of stem defects were studied over a 16-year 

period to determine the effect of thinning intensity on the development of tree 

quality. We studied quality changes on sample white oak crop trees that were 

selected from five density levels created in a 1961 thinning. Branch-related and 

other stem defects on the butt 16-foot section were studied from stereo pairs of 

photographs taken in 1961 and 1977. The number of live and dead branches 

greater than 0.3 inch in basal diameter increased on all density plots. Except for 

extremely heavy thinnings, those below C-level stocking, tree quality was not 

markedly affected by residual stand density. 
Methods 

The goal of hardwood managers 

often is to produce high-quality trees for 

lumber or veneer in the shs~est 

possible time. A primapd means of 

achieving this is regulating residual 

stand density through a sertes sf 

intermediate cuttings. These treatments 

affect the grovvth rate of individual trees 

as well as the development of bole 

quality. Gingrich (1 970) suggested that 

thinnings in hardwoods should depend 

more on species composition, tree 

vigor, and potential stern quality than 

merely on groMh response due to 

reduced stand density. The sNects of 

residual stand density on growth rates 

are better understood and documented 

than its effects on the development of 

stem quality. Phis reporZ summarizes 

research findings on the development 

of limb-related defects and other quality 

characteristics associated with a range 

of residual stocking levels created by 

an earlier thinning. 

Cull, defective, and lower quality 

stems are removed during nn"irmedia2e 

cutting; and this process of eliminating 

undesirable trees theoretically 

enhances the development sf highquality stems. However, detrimental 

effects on stem quality can result, 

especially from extremely heavy cueing. 

The rate of natural pruning of live limbs 

also can be reduced and, in some 

instances, heavy cutting promotes 

increased branching and degrade 

through epicormic sprouting. Generafly, 

changes in tree quality occur very 

slowly, so it is difficult to detect and 

quantify this rate of change on an 

objective basis. And little response data 

are available from long-term studies of 

changes in tree quality. 

Research on bole-quality 

development following thinning has 

been neglected hut not ignored 

completely. Stem-quality development 

in hardwoods is recognized to he at 

least as imporlant as growth in defining 

optrmurn stocking regimes (Tubbs 

1977). Since branch-related defects are 

the most common cause of degrade in 

hardwoods (Brym 1958: Godman and 

Books 1 971 j, the effect of stand 

slacking on branch occurrence, 

development, and retention is especially 

imporlarat, In the oak type, Brinkman 

("1955) reported that the tendency for 

indivlduat trees lo develop epicormic 

branches might be inherited, though the 

amount of branching was influenced by 

degree of parlial cutting and the relative 

crown class. More epicormic branches 

were found in understocked stands and 

on trees in the subdominant crown 

position. Krajieck (1 959) reported 

similar results for a 95-year-old stand of 

white oak where dominant stems had 

fewer than 3 epicorrnic branches on the 

tower 17 feet, while stems in other 

crown classes had 6 to 10 branches. 

Oaks are more prone to develop 

epicorrnic branches than species such 

as yellow-poplar or white ash (Smith 

1966). White oak apparently produces 

and retains more branches or 

epicsrmics than most other species, 

even other oaks (Della-Bianca 1983). 

Research has shown that in hardwood 

Forests the occurrence and persistence 

of branches-both living and deadvaries with species, tree age, crown 

class, site quality, and stand density. 

This study examined changes in 

various types of limb-related defects 

and other tree-quality factors for white 

oak crop trees over a 16-year period. 

We were especially interested in the 

relative rate of change in defect 

indicators over the extremely broad 

range in stand densities created by an 

initial thinning in 1961. The rate of 

change and the trends in potential tree 

defects coupled with information on 

growth and cost of treatment will help 

evaluate tree and stand values and 

sewe as a basis for selecting 

silvicul"era1 treatment regimes. 

Data on tree quality were collected 

on sample crop trees from a thinning on 

the Daniel Boone National Forest, 

Jackson County, Kentucky. The design 

consisted of fineen 7:2-acre plots, plus 

an isolation zone of about "2 acre 

surrounding each plot. At the time of 

the initial thinning in 1961, this fully 

stocked natural white oak stand was 33 

years old and showed no evidence of 

fire, cut"tng, or other disturbance. All 

plots were remarkably uniform in basal 

area, age, distribution of size class, 

species composition, and site quality. 

Before thinning, the plots averaged 687 

trees per acre that were 2.6 inches or 

larger in d.b.h, and 75 ft2 of basal area. 

The average mean stand diameter was 

4.5 inches and the average site index 

was 70. White oak was the principal 

species accounting for more than twothirds of all trees over 2.6 inches in 

d.b.h. Other oaks, mainly black and 

scarlet, accounted for 19 percent of the 

trees, white hickory, black gum, and red 

maple accounted for most of the 

remaining 14 percent. 

Three plots each were thinned to 

residual basal areas of 15, 30, 45, and 

60 ft2 per acre, leaving the three control 

plots with approximately 75 ft2 per acre. 

The objective was to leave a suitable 

number of the best stems as evenly 

spaced as possible over the plot. In 

general, we cut the larger cull and 

defective trees first, then the competing 

trees of poor form and quality, then the 

intermediate and suppressed trees of 

lower quality and value. Finally, if 

necessary, we cut the lower value 

species of the main crown class. Mighquality desirable species were cut also 

if necessary to achieve a uniform 

spatial distribution. Table 1 shows that 

much of the thinning was from below. 

Dominant and codominant white 

oak trees that were well dispersed over 

the plot were selected as sample trees. 
Table 1 .-Relative frequency of trees larger than 2.6 inches in dbh after 1961 thinning, 

by crown class 

-- 

Residual basal area after 1961 thinning (ftZ!acre) 

Crown class 15 30 45 60 75 

Number Percent Number Percent Number Percent Number Percent Number Percent 

Dominant 22(5.4)a 18 30(5.9) 12 33(6.4) 8 54(6.1) 8 46(6.7) 7 

Codominant 64(4.9) 53 127(4.9) 49 181(5.0) 45 217(4.7) 34 233(4.7) 33 

Intermediate 34(3.9) 28 88(4.0) 34 1 lg(3.8) 29 198t3.7) 31 176(3.6) 25 

Suppressed l(3.8) 1 13(3.4) 5 72(3.1) 18 168(3.0) 27 247(3.2) 35 

"Quadratic mean diameter in parenthesis. 

They were selected because of their 

high potential as crop trees based on 

tree vigor, crown position, dbh, and the 

apparent quality judged by form, 

straightness, freedom from branches, 

and other defect indicators. Five of 

these sample trees were selected 

randomly to determine changes in tree 

quality by the stereo-photo technique 

described by Worley and Dale (1 960). 

This technique entailed taking stereo 

pairs of photographs from the four 

cardinal directions in 1961 and again in 

1977 after 16 growing seasons. 

Because of the poor quality of some of 

the 1961 photographs, the sample 

consisted of only 66 trees. 

Various types of stem 

characteristics and limb-related defects 

were identified and classified on each 

sample tree from 1961 and 1977 

photographs. Prints of each negative 

were enlarged to 8 x 10 inches and 

examined with 4-power stereoscopic 

binoculars. Other tree characteristics 

such as dbh, crown class, crown length, 

and total tree height were observed or 

measured in the field on both 

occasions. In 1961 , total height and 

crown length were measured with a 

Haga altimeter.Targets and a range 

The use of trade, firm, or corporation 

names in this paper is for the information 

and convenience of the reader. Such does 

not constitute an official endorsement or 

approval by the U.S. Department of 

Agriculture or the Forest Service of any 

product or service to the exclusion of 

others that may be suitable. 

finder were used to establish a 

horizontal distance 1 chain from the 

measured tree. In 1977, these 

measurements were taken with a 

relaskop at a taped distance of 75 feet 

from the tree. Crown length was 

measured starting with the first major 

branch in the main crown. 

To verify the reliability of classifying 

branch defects from the photographs, 

we conducted an independent field test 

using the 1977 data. The number of 

branches, alive or dead, and branch 

size were classified independently in 

the field in 1977 and compared with 

data as observed and classified from 

the 1977 photographs. We were able to 

identify the total number of branches on 

the 16-foot butt section very well, 

obtaining a correlation between photo 

and ground observations of 0.98. This 

technique was not as accurate in 

determining whether the branches were 

alive or dead, but we were able to 

correctly classify the status, obtaining a 

correlation of 0.8. 

Results and Discussion 

As was expected, it was easier to 

document the effects of thinning on 

groah than on quality characteristics. 

The main focus of this paper is on 

quality, but growth is discussed briefly 

because of its importance in evaluating 

thinning practices. 

Diameter Growth 

The effect of stocking on growth 

was quite evident over the 16-year 

period for tree characteristics such as 

dbh and cubic volume (Table 2). Mean 

diameter growth of sample trees on the 

lowest density plots was twice as great 

as on the control plots. Differences in 

mean diameter growth due to thinning 

treatments were highly significant 

(P < 0.01 ). From the lowest to highest 

stocking, annual diameter growth was 

respectively: 0.28, 0.23, 0.18, 0.1 6, and 

0.1 4 inch, or an increase over control of 

100, 64, 28, and 14 percent. Hilt (1 979) 

reported similar growth trends in 

relation to stocking based on a much 

larger base. 

Height Growth 

The effect of stocking on height 

growth appeared to follow a different 

pattern than for diameter or cubicvolume growth (Table 2). Mean height 

growth from lowest to highest stocking 

was, respectively: 1 5.4, 1 7.3, 1 7.4, 

1 6.6, and 13.3 feet. Covariance 

analysis, adjusting for initial tree height, 

indicated no significant difference in 

mean height growth due to treatment. 

Cubic-Volume Growth 

Stocking level influenced cubicvolume growth even more than 

diameter growth but followed the same 

pattern (Table 2). Cubic-volume growth 
Table 2.-Summary of average sample tree characteristics 

in 1961 and 1977 for each thinning treatment 

Residual basal area after 1961 thinning (ft2/acre) 

Characteristic Year 15 30 45 60 75 

Dbh (inches) 

Crown class 

(% of trees) 

Dominant 

Codominant 

Dominant 

Codominant 

Intermediatesuppressed 

Crown ratio 

(% live crown) 

Total height (ft) 

Sweep and crook 

(departure in 

inches, 16-foot 

butt log) 

Cubic volume 

(ft3) 

Stem surface 

area on butt 

16-foot (ft2) 

was 2'/3 times greater per tree at the 

lowest stocking compared with the 

control. This was expected since 

diameter in the volume equation is 

squared while height enters as a linear 

term. From lowest to highest stocking, 

growth in volume for 16 years was, 

respectively: 13.2, 1 1 .I, 9.0, 6.7, and 

5.7 cubic feet per tree, or an increase 

over the control of 132, 95, 58, and 18 

percent. Differences in mean cubicvolume growth between density levels 

after adjusting for initiaf volume were 

highly significant (P < 0.01). Although 

growth per tree is greatest at the lowest 

stocking, there are too few trees (1 21 

per acre, Table 1 ) to fully occupy the 

site; hence, on a per-acre basis, growth 

is less at the lowest stocking level (Dale 

1972). 

Tree Crown 

Stand density influenced both the 

crown position and crown ratio of 

sample trees. As was expected, the 

proportion of trees in the dominant 

crown class increased with lower 

stocking. Likewise, crown ratio 

increased. The crown class and crown 

ratios shown in Table 2 for 1961 were 

observed before thinning. In 1977, more 

of the sample trees at the lower 

stocking levels had a dominant crown 

position and greater crown length. 

These characteristics probably are 

responsible for the increased diameter 

and cubic-volume growth. 
In 1 961 there was iinte difference 

in crown length between density levels; 

the average was about 22 feet overall. 

By 1977, the average crown length was 

about 34 feet at the lowest stocking but 

had decreased to about 16 feel on the 

control plots. After adjusting for initial 

crown length, the dinerenee in crown 

length in 197'7 between treatments was 

highly significant (P < 8.01 ). 

Statistical tests on total height, 

crown length, and diameter groWh 

were recomputed, omitting trees that 

were intermediate or suppressed in 

1977. Earlier results were not changed 

appreciably, though the mean diameter 

and mean total height increased slightly 

over the values given in Table 2 for 

density levels 60 and 75, 

Quality Characteristics 

Tree quality is not one single 

measureable characteristic but consists 

of many factors, some of which may 

depend on the intended product. 

Certain tree characteristics or factors, 

however, are generally regarded as 

desirable for most products. Such 

quality indicators might be stem 

straightness, freedom from branches 

and overgrown knots, absence of forks 

and crooks, few insect holes or 

wounds, no seams, and no evidence of 

internal or external decay. 

In this study we identified and 

classified several Vpes of defects or 

quality indicators such as crook and 

sweep; various classes of live and dead 

branches; forks; and overgrovvths. 

Since limb-related defects are the 

greatest deterrent to potential tree 

quality (Godman and Books 1971 ; 

Bryan 1958), mast of the analysis deals 

with various types and sizes of 

branches. It is dinicult to interpret the 

effect of stocking on branch 

development unless all branch-related 

defects are considered simultaneously. 

For example, over the 16-year period it 

is possible for some small epicormic 

branches to develop into large. live 

limbs, later die, and finalfy drop from 

the stem and become overgrovvths. 

Specific defects must be identified and 

their development traced over time ts 

develop this information. We are doing 

this in a separate study. In this anafysis 

we classified the various types of 

defects from the 1961 and 1977 

photographs independently. 

Branch Characteristics 

The several categories of branches 

we recognized depended on size and 

whether the twig was alive or dead. 

Twigs that were alive and smaller than 

0.3 ineh in diameter at the base were 

classified as epicormic. Limbs 0.3 ineh 

or larger in diameter were calisd 

branches and further classified as alive 

or dead (Table 3). The number of 

branches on the butt 16-1001 section 

was recorded on each of the 8-foot 

stern sections, When the entire d 6-foot 

log was considered (Table 31, it is 

obvious that the number af trees with 

live branches increased at all density 

levels between 1961 and 4 977. The 

greatest increase in the number sf live 

branches was at the iswest stocking 

level; here, the number sf trees with 

branches increased from about 8 

percent in 1961 to 92 percent in 1977. 

Although there were significantly more 

trees with branches in 1977 than in 

1961, the increase did not appear 

entirely related to stocking level. Many 

Wigs were less than 0.3 inch in 

diameter in 1961, but in 1977, they had 

grown larger and were classified as 

branches. We believe that most 

branches developed from the numerous 

epicormics present on most trees 

before the initial thinning in 1961 

(Fig. 1). 

Not enty did more "irees have 

branches in 1977, regardless of the 

density level, but there were more 

branches per tree. Tabte 3 shows tkat 

about 46 percent of the sample trees 

on the lowest density plots had at least 

five or more branches per tree, The 

following shows the average number of 

live and dead branckes per tree far the 

4 6-fwt section at each density level: 

Branch Residual basal area h 1961 

15 50 45 60 75 

Live 5.8 2.46 1.92 1.79 

Dead 3.6% 1.15 0.85 ~8.615 c0.50 

Except for the csntroi plots, the number 

of live branches decreased as stand 

density increased. 

Covariance analysis that adjusts for 

the initial number of live branches in 

19B"iindicaled tkat the effect of density 

on number of live branches was 

significant (P < 0.08). Comparison of 

density tevels revealed significantly 

more live branches only at the lowest 

density ievet . 

The eMect of density on the 

number of dead branches was more 

evident. In 1961 there was no 

dinerenee between density levels in the 

number of trees with dead branches on 

the butt 16-foot log (Table 3). The 

lowest density tevel had the most trees 

with dead branches, 40 percent in 

1961, and all of the trees in 1977. Only 

the highest stocked plots showed a 

decrease In number of trees with dead 

branches between 1961 and 1977. The 

difference between density levels in the 

number sf dead branches in 1977 was 

highly significant (P c 0.01). The lowest 

density had the most dead branches in 

1979 but the lower two stocking levels 

were significant!), different than the 

higher stocked plots (P < 0.01). The 

tabulation also shows that there were 

still more living than dead branches at 

all density levels in 1977. 

There were significantly more living 

and dead branches in the upper 8-foot 

section of the butt 16-foot log. A 

comparison of the living branches for 

the Iower and upper sections is shown 

in Table 4. Analyses indicated that the 

effect 08 stand density on both living 

and dead branches was the same for 

the upper section as for the ?&foot log. 

NO analyses were performed on the 

tower stem section because iess than 

23 percent sf sample trees had either 

living or dead branches on the lower 8 

feet, 
Table 3.-Percentage of sample trees in 1961 and 1977 

by number of living and dead branches 

(butt 1 ti-foot log) 

Residual basal area in 1961 (ft2/acre) 

Number of 

branches 15 30 45 60 75 

1961 1977 1961 1977 1961 1977 1961 1977 1961 1977 

LIVING 

DEAD 
Figure 1 .-Typical 50-year-old white oak trees in fully stocked stands have 

many epicormics. 
Table 4.-Percentage of sample trees in 1961 and 1977 

by number of living branches in butt and 

second sections of I 6-foot log 

Residual basal area in 1961 (ft2iacre) 

Number of 

branches 15 30 45 60 75 

BUTT SECTION 

SECOND SECTION 
Epicormic Branches 

Small epicormic branches were 

difficult to identi@ and count accurately 

from the photos so we only 

three broad categories of trees with 

epicomic branches: none, one to six, 

or seven or more epicormics for each 

8-foot section (Table 5). In both 

sections there were few trees with no 

and 1977 except at the lowest stocking foot section, ranging from 1.0 inch at 

level. the lowest stocking to only 0.58 inch at 

the highest stocking. There was no 

correlation between stocking and size 

Branch Size of dead branches after 10 years. In the 

future, dead branch size likely will be Average diameter Of the largest larger on the lower stocking levels since living and dead branch on each 8-foot the live branches present today are section is given in Table 6. Live branch now larger on the low-density plots. size on the second 8-foot section was 

epicormics in 1961. The percentage of significantly (P c 0.01) related to 

trees free of epicormics on the butt 8- stocking level. Branch size also We believe that the development of 

foot section in 1977 ranged from 23 appeared to decrease with increasing an extremely dense understory on the 

percent at 15 ft2 of basal area to 53 stocking on the lower sections, but no lower stocked plots (Fig. 2) may help 

percent at 30 ftz of basal area (Table analyses were attempted because too explain some of the changes in branch 

5). The number of trees with no few trees had branches. Live branches size and number of dead branches. 

epicormics increased between 1961 were slightly larger on the second 8- Initially, the lower bole of sample trees 

Table 5.-Percentage of sample trees in 1961 and 1977 

by the number of epicormic branches in butt 

and second section of 16-foot log 

Residual basal area in 1961 (ft2iacre) 

Number of 

epicormics 15 30 45 60 75 

BUTT SECTION 

SECOND SECTION 
Table 6.-Average size (basal diameter) of largest 

live and dead branch on each tree in 

1961 and 1977 

Residual basal area after thinning (ft2!acre) 

Item Year 15 30 45 60 75 

Live limbs 

Butt 8-foot 

section 

Live limbs 

Second 8-foot 

section 

Dead limbs 

Butt 8-foot 

section 

Dead limbs 

Second 8-foot 

section 

Inches - - 

Figure 2.-Typical dense understory on a 

lower stocking plot in 1977. 
was exposed to a great deal of direct 

sunlight, so epicormics developed and 

grew rapidly to branch size 

classification. A few years later, a 

dense understory was shading the 

lower 8-foot section, causing branch 

mortality or restricting growth. After 16 

years, the understory is 25 to 30 feet 

tall and is shading the entire lower 16 

feet. Even if branches die as quickly 

now on the lower as on the higher 

stocked plots, branches are larger and 

may require a longer period to drop off 

and become overgrown by clear wood. 

Also, the trees already are larger in 

diameter so even if branches do die 

shortly, the knotty core will be larger at 

the lower stocking levels. 

Defects Per Square Foot of the highest stocking. This ratio 

Surface Area decreased as stocking increased from 

7.9, 6.2, 4.1, 2.3 and 1.8. Live or dead 

The number of defects per square branches on the second 8-foot section 

foot of stem surface area provides a were responsible for most of the 

relative comparison of the effect of increase. 

stocking on stem quality. Table 7 shows 

the number of live or dead branch 

defects per square foot of surface area. 

The number of such defects per square 

foot increased on all density levels over 

the 16-year period, but the greatest 

increase was on the lowest density 

plots. The ratio of 1977 to 1961 defects 

per square foot for the 16-foot log 

indicates nearly 8 times more defects 

per square foot in 1977 at the lowest 

stocking and nearly twice as many at 

Table 7.-Number of live and dead limb defects per square foot of stem surface area 

Residual basal area after 1961 thinning (ft2/acre) 

Item Year 15 30 45 * 60 75 

Butt 1961 - 0.005 - - - 8-foot log 1977 0.056 0.025 0.022 0.01 2 0.026 

Second 1961 0.071 0.032 0.056 0.047 0.102 

8-foot log 1977 0.482 0.223 0.197 0.094 0.1 56 

Entire 1961 0.031 0.01 8 0.024 0.021 0.045 

16-foot log 1977 0.244 0.1 12 0.099 0.048 0.083 
Summary and Conclusions 

The results presented here 

represent only one age and one size 

class and apply only to white oak. More 

comprehensive studies must be 

completed across a broad range of age, 

site, and species before specific 

remmmendations can be offered. 

However, the data suggest that the 

effect of stocking on potential stem 

quality may be substantial. The findings 

in this study indicate that: 

1. The number of limb-related defects 

decreases with increasing residual 

stand density. 

2. The size of live limbs decreases in 

both upper and lower 8-foot logs 

with increasing residual stand 

density. 

3. Live limbs generally are larger in the 

upper log. 

4. In this relatively young pole timber 

stand, there are still more living than 

dead branches on the 16-foot log, 

regardfess of the residual basal 

area. 

5. The average number of branchrelated defects on the butt 16-foot 

log decreases from a high of nine 

per tree at the lowest stocking to 

one to three on the higher stocked 

plots. 

6. The number of epicormic branches 

on both the lower and upper 8-foot 

sections generally have decreased 

since 1961 because many have 

grown to branch classification size. 

However, epicorrnic branches still 

are numerous on both sections after 

16 years, regardless of stand 

density, and remain a potential 

source of future defects. 

Extremely heavy initial thinning in 

these young oak stands certainly 

delays, if not substantially reduces, the 

potential to develop high-quality sterns. 

Except for extremely heavy thinning, 

the residual density does not seem to 

markedly affect stem qualiw. If sufficient 

trees are left to fully use the sites 

(about 60 percent or more stocking, 

Roach and Gingrich 1968) any slight 

loss in quality may be compensated for 

by trees growing faster or reaching 

maturity sooner than those in unthinned 

stands. More study is needed on 

growth, quality, and economic factors 

before specific thinning regimes can be 

recommended for the white oak timber 

type. Meanwhile, it appears from this 

study that tree quality will not be 

seriously affected so long as stocking is 

50 percent or more after thinning. 
Literature Cited 

Brinkman, K.A. Epicormic branching 

on oaks In sprout stands. Tech. 

Pap. 146. Washington, DC: U.S. 

Department of Agriculture; 1955. 8 p. 

Bryan, W.C. Defect in Piedmont 

hardwoods. Res. Note SE-115. 

Asheville, NC: U.S. Department of 

Agriculture, Forest Service, 

Southeastern Forest Experiment 

Station; 1958. 2 p. 

Dale, Martin E. Growth and yield 

prdlctions for upland oak stands 

10 years after initial thinning. Res. 

Pap. NE-241. Upper Darby, PA: US. 

Department of Agriculture, Forest 

Service, Northeastern Forest 

Experiment Station; 1972. 22 p. 

Della-Bianca, Lino. Effect of intensive 

cleaning on natural pruning of 

cove hardwoods in the Southern 

Appalachians. For. Sci. 29: 27-32; 

1983. 

Gingrich, Samuel F. Effects of density, 

thinning, and species composition 

on the growth and yield of eastern 

hardwoods. In: The silviculture of 

oaks and associated species. Res. 

Pap. NE-144. Upper Darby, PA: U.S. 

Department of Agriculture, Forest 

Service, Northeastern Forest 

Experiment Station; 1970. 26-35 p. 

Godman, R.M.; Books, D.J. Influence 

of stand density on stem quality in 

pole-size northern hardwoods. 

Res. Pap. NC-54. St. Paul, MN: U.S. 

Department of Agriculture, Forest 

Service, North Central Forest 

Experiment Station; 1971. 7 p. 

Hilt, Donald E. DZameter growth of 

upland oaks after thinning. Res. 

Pap. NE-437. Broomall, PA: U.S. 

Department of Agriculture, Forest 

Service, Northeastern Experiment 

Station; 1979. 1 1 p. 

Krajicek, John E. Epicormlc branching 

in even-aged, undisturbed white 

oak stands. J. For. 57: 372-373; 

1959. 

Roach, B.A.; Gingrich, S.F. Even-aged 

silviculture for upland central 

hardwoods. Handb. 355. 

Washington, D.C. : U.S. Department 

of Agriculture; 1968. 39 p. 

Smith, H. Clay. Epicorrnic branching 

on eight species of Appalachian 

hardwoods. Res. Note NE-53. Upper 

Darby, PA: U.S. Department of 

Agriculture, Forest Service, 

Northeastern Forest Experiment 

Station; 1966. 4 p. 

Tubbs, Carl H. Managers handbook 

for northern hardwoods in the 

North Central States. Gen. Tech. 

Rep. NC-39. St. Paul, MN: U.S. 

Department of Agriculture, Forest 

Service, North Central Forest 

Experiment Station; 1977. 29 p. 

Worley, David P.; Dale, Martin E. 

Recording tree defects In stereo. 

Tech. Pap. 173. Columbus, OH: U.S. 

Department of Agriculture, Forest 

Service, Central States Forest 

Experiment Station; 1960. 1 1 p. 
Dale, Martin E.; Sonderman, David L, Effect of thinning on growth and potential 

quality of young white oak crop trees. Res. Pap. NE-539. Broomall, PA: U.S. 

Department of Agriculture, Forest Service, Northeastern Forest Experiment Station; 

Relative changes in several types of stem defects were studied over a 16-year 

period to determine the effect of thinning intensity on the development of tree 

quality. Sixty-six sample white oak crop trees represented each of five density 

levels created by thinning a young white oak stand in Kentucky in 1961. 

Occurrence of branch-related and other stem defects on the butt 16-foot section 

was studied from stereo pairs of photographs taken in 1961 and 1977. The 

number of live and dead branches greater than 0.3 inch in basal diameter 

increased on all density plots. Except for extremely heavy thinnings, those below 

6-level stocking, tree quality was not markedly affected by residual stand density. 

ODC 228.1 :242:851:852.11 

Keywords: Silviculture; thinning; bole quality 
Headquarters of the Northeastern Forest Experiment Station are in 

Broomall, Pa. Field laboratories are maintained at: 

Amherst, Massachusetts, in cooperation with the University of 

Massachusetts. 

0 Berea, Kentucky, in cooperation with Berea College. 

Burlington, Vermont, in cooperation with the University of 

Vermont. 

Delaware, Ohio. 

Durham, New Hampshire, in cooperation with the University of 

New Hampshire. 

0 Hamden, Connecticut, in cooperation with Yale University. 

Morgantown, West Virginia, in cooperation with West Virginia 

University, Morgantown. 

Orono, Maine, in cooperation with the University of Maine, 

Orono. 

Parsons, West Virginia. * Princeton, West Virginia. 

Syracuse, New York, in cooperation with the State University of 

New York College of Environmental Sciences and Forestry at 

Syracuse University, Syracuse. 

@ University Park, Pennsylvania, in cooperation with the 

Pennsylvania State University. 

Warp :n, Pennsylvmia. 

*U.S. GOVERNMENT PRINTING OFFICE: 1 9 8 4 7 0 5 0 2 9 3 1