United States 

Department of 

Agriculture 

Size of Clearcut Opening Affects 

Forest Service Species Composition, Growth Rate, 

Northeastern Forest 

Experiment Station 

and Stand Characteristics 

Research Paper NE-698 

Martin E. Dale 

H. Clay Smith 

Jeffrey N. Pearcy 
Abstract 

In the late 1950's and early 1960's, a series of studies was installed in the central 

hardwood forest to determine if size of clearcut opening affects the growth rate and 

species composition of new stands. In 1991, about 30 years after cutting, stand data 

were collected in 89 openings ranging in size from 0.04 to 1.61 acres. Species 

composition varied from locations in West Virginia to those in Illinois and from Ohio to 

Kentucky. For example, there were more maple and birch in West Virginia than in 

Illinois, regardless of opening size. Some of the difference in species composition and 

growth rate is related to site quality but there also are differences due to size of opening. 

Most of the oak and hickory were on the poorer sites while yellow-poplar was more 

abundant on the better sites. The number of stems per acre increased with opening 

size; however, the number of stems of shade-tolerant species constituted a greater 

proportion of the stand in small openings (< 0.5 acre), while the proportion of intolerant 

species increased in larger openings. Basal area and volume of the current stands 

seem to increase markedly with opening size for openings up to at least an acre. The 

greatest reduction in growth is nearest the border of the opening, though some effect on 

growth extends at least 100 feet into the opening. There also is a strong interaction 

between border effect and opening size. Productivity is greater at a given distance from 

the border for larger openings. Opening size has a major influence on stand 

characteristics after about 30 years. 

The Authors 

MARTIN E. DALE (retired), joined the USDA Forest Service in 1957, specializing in 

forest management and silviculture research at Berea, Kentucky. In 1973, he received a 

Ph.D. degree in forest biometry from Iowa State University, and since 1970 had been 

assigned to the Northeastern Forest Experiment Station's research unit on timber 

measurement and management planning at Delaware, Ohio. 

H. CLAY SMITH (retired) was principal silviculturalist at the Northeastern Forest 

Experiment Station's Tmber and Watershed Laboratory at Parsons, West Virginia. He 

received B.S. and MS. degrees from West Virginia and Purdue Universities, and joined 

the Northeastern Forest Experiment Station in 1962. 

JEFFREY N. PEARCY, research associate, received B.S. and MS. degrees in forestry 

from Ohio State University. He worked at the Northeastern Forest Experiment Station, 

at Delaware, Ohio, in 1992 before returning to the School of Natural Resources at Ohio 

State University. 

Manuscript received for publication 2 June 1994 

- 

USDA FOREST SERVICE 

5 RADNOR CORP CTR STE 200 

PO BOX 6775 

RADNOR PA 19087-8775 

May 1995 
Introduction 

Due to concerns about the adverse effects of clearcutting 

on species diversity, wildlife habitat, and aesthetic values, 

forest managers are seeking alternative timber harvesting 

techniques, including individual-tree partial cuts or the use 

of small openings for reproducing forests. Silviculturalists 

have long known that various cutting methods can be 

used to control light and moisture conditions and thus to 

create environments that favor or discriminate against a 

particular species. Small openings can provide a pleasing 

and suitable environment for some purposes. However, 

managers interested in timber production are equally 

concerned about the potential loss of production and 

certain tree species from these alternate methods 

compared with what could be achieved with some form of 

clearcutting. 

Small openings in the canopy created by harvesting single 

trees or clearcutting small openings up to 2 acres in size 

have caused a shift in species composition (Walters and 

Nyland 1989). Also, small clearcuts have a much larger 

proportion of their total area influenced by the surrounding 

forest than larger clearcuts (Marquis 1965). The 

increased competition for sunlight and moisture from this 

edge effect is likely to further reduce tree growth. 

Reduced height growth of new regeneration has been 

reported near the opening edge for at least 10 to 20 years 

after small group-selection cuts (Sander and Clark 1971; 

Minckler and Woerheide 1965; Willison 1981). Although 

reduced height and diameter growth has been reported, 

little is known about the magnitude of this reduction or 

how far into the opening this border effect extends. 

"7 Kas kaskia 

Our objective in this investigation was to determine the 

magnitude of this border effect for small forest openings 

created 30 years ago in mature upland oak stands. Also, 

we wanted to learn if the size of opening affected species 

composition and growth rates (productivity), and how far 

the border effect extended into the opening. Thirty years 

is a relatively short interval in the life of a forest stand and 

we realize that forest stand conditions are subject to 

change. The results presented here represent what has 

occurred after 30 years. 

Methods 

In the late 1950's and early 1960's, a series of 

regeneration studies was installed at five locations in the 

upland oak type in West Virginia, Ohio, Kentucky, and 

Illinois (Fig. 1) to determine if size of opening or site 

quality affected the growth rate andlor species 

composition of newly regenerated stands. These initial 

efforts encompassed 198 circular plots that ranged in size 

from 0.04 to 5 acres. These early efforts had essentially 

the same study objective but there were differences in the 

initial species composition, site quality, age of stand, and 

opening size created at each location, and in treatments 

applied. We did not perform statistical tests of location 

differences because of unequal samples by site and 

opening size at each location. Despite these differences, 

we believe that the similarity in pattern of response with 

respect to size of opening and border effect justify 

combining results to look at the generalized response 

about 30 years after treatment. 

Indiana Ohio 

I Furnace 

Figure 1 .--Location of study areas. 
Table 1.--Characteristics of openings by location, 1991 

Heiaht of 

Location 

., Number of openings Site Opening size border 

Original Remeasured index Stand age Range Mean trees - - 

Years - - - - - - - - - Acres -------- Feet 

Fernow 72 29 Fair to 25 0.04 to1.29 0.46 89 

Good 

Vinton 36 15 Fair to 31" 0.15 to 1.17 0.56 88 

Good 

Robinson 36 15 Fair 0.06 to 1.31 0.46 91 

Baldrock 36 14 Fair to 

Good 

Kaskaskia 18 16 Fair to 32 0.04 to 0.75 0.20 74 

Good 

Total 198 89 

"Cutting was extended over 3 years, so some plots were 30 and some 32 years old. 

The basic treatment applied to all openings on the Vinton 

Furnace Experimental Forest in southeastern Ohio was to 

remove all merchantable material by conventional 

commercial logging, and then fell or girdle all remaining 

stems more than 4.5 feet tall. Essentially the same 

treatment was used at Kaskaskia Experimental Forest in 

southern Illinois except that all stems more than 1.5 feet 

tall were cut (Minckler et al. 1973). At the other three 

locations, the amount of site preparation varied somewhat 

but basically consisted of removing various amounts of 

vegetation following conventional commercial logging. On 

the Fernow Experimental Forest in north-central West 

Virginia, all stems 5.0 inches and larger in d.b.h, were cut. 

On some plots, 2,4,5-T herbicide mixed in fuel oil was 

used as a basal spray and applied to residual trees 1.0 to 

4.9 inches d.b.h. (Smith 1981). Small trees on other plots 

at Fernow also received the basal spraying treatment with 

herbicide; all recently cut stumps of undesirable timber 

species also were sprayed to prevent resprouting. 

On the University of Kentli~ky's Robinson Experimental 

Forest in eastern Kentucky, he basic treatment consisted 

of logging and then killing all trees 3 to 'I2 inches d.b.h. by 

frilling and using 2,4,5-T herbicide mixed in fuel oil (Hill 

1967). In addition, some plots on the Robinson Forest 

received a more intensive treatment designed to kill all 

trees smaller than 3 inches d.b.h., with the herbicide 

mixture applied as a basal spray; on still other plots, on!y 

the undesirable species for timber received this more 

intensive spray treatment. On the Baldrock Experimental 

Forest in southeastern Kentucky, the basic treatment was 

the same as for the Robinson plots for trees larger than 3 

inches. Three additional treatments were applied to 

control vegetation less than 3 inches d.b.h., including 

basal spraying the 2,4,5-T herbicide mixture with hand 

sprayers; mist blowing the understory before logging with 

2,4,5-T using a solo' backpack mist blower; or using a 

bulldozer to scrape away the vegetation and expose 

mineral soil over most of the plot (Sander and Clark 

1971). Although some of these site-preparation 

treatments have been reported to increase the amount of 

yellow-poplar, such treatments generally did not increase 

the amount of oak regeneration, nor did they effectively 

reduce the number of undesirable trees (Sander and 

Clark 1971). However, some of these treatments 

influenced the amount and development of stems of 

sprout origin. We did not detect differences due to 

site-preparation treatment in the trends reported here with 

respect to opening size and extent of edge effect. 

In 1991, only 89 of the original 198 plots were sampled, 

primarily because of limited funds. Criteria for plot 

selection were based on plot size and site. Plots selected 

at each location were: Fernow Experimental Forest (29 

plots); Vinton Furnace Experimental Forest (15); Robinson 

and Baldrock Experimental Forests (15 and 14, 

respectively); and Kaskaskia Experimental Forest (16) 

(Table I). The distribution of sample plots by opening 

size, site, and locat~on is giver! in Appendix Table 10. 

Our current sample of plots ranged In size from 0.04 to 

1.61 acres: the sites were typical of the upland oak type 

(site index 55 to 80 for black oak). At the Vinton, Fernow, 

and Baldrock locations, the original study design 

attempted to locate openings on two general site classes: 

 h he use of trade, firm, or corporation names in this paper is 

for the information and convenience of the reader. Such use 

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. 
fair (site index 56 to 65) and good (site index 66 to 75) for 

black oak. In Illinois, openings were located on three 

topographic positions: a northeast slope, a southwest 

slope, and a cove. Thus, site index again encompassed a 

range of sites from fair to good. Only one general site 

class was covered at the Robinson location, where all 

plots were established on the south side of a main ridge 

between two watersheds. Site index at the Robinson 

location generally was fair and ranged from 55 to 65 for 

oaks. In selecting our sample from the original plots, we 

tried to sample across the range of sites and opening 

sizes available at each location as well as across various 

site-preparation treatments. At the Baldrock location, 

most of the original plots were destroyed by subsequent 

clearcutting, so the actual selection of plots was limited; 

however, we were able to cover all plot size and site 

conditions. 

Sampling Design 

In all except the smallest openings, eight transects were 

established along the cardinal and off-cardinal directions 

(Fig. 2). Along each transect, 20.9- by 20.9-foot square 

subplots (0.01 acre) were established that extended from 

the opening's border toward its center. On the smaller 

Figure 

plots, only the off-cardinal transects were used to prevent 

overlap of the 0.01-acre subplots. The edge of opening 

was estimated for each transect so as to fall on the arc 

formed between stems of the original border trees (Fig. 2). 

From this beginning point, each transect was extended an 

additional 20.9 feet into the surrounding forest. Subplots 

were then numbered consecutively from this outside plot 

toward the opening center. Normally, we would continue 

to establish subplots along the off-cardinal transects until 

the center was reached. Subplots along the cardinal 

direction transects were established until they began to 

overlap with adjacent subplots along the off-cardinal 

transects. 

Along the transects we recorded average percent slope 

and distance from the border to the opening's center, as 

well as percent slope, aspect, and elevation of each 

subplot. In later analyses, slope measurements were 

used to determine the precise horizontal subplot acreage; 

in turn, these values were used to compute stand 

characteristics on per-acre basis for each subplot. We 

also recorded the distance from the opening border to the 

two tallest trees on each subplot. Total height of these 

sample trees was measured. 

2250 o 135O 

180° 

2.-Sampling design of openings using eight transects. 
Table 2.-Distribution of subplots by distance from border and opening size 

Subplot positiona 

Group Opening 

no. size 1 2 3 4 5 6 7 8 9 Total 

6 >3.0 32 32 32 96 - 

Total 463 445 337 234 138 35 52 36 33 1773 

aPosition 2 extended 20.9 feet from the opening perimeter toward the plot center, with a midpoint distance of 10.4 feet from the 

edge of the opening. Position 1 extends 20.9 feet into the surrounding forest stand, thus, -10.4 feet. Midpoint distances for 

positions 3 through 9 are 31.3,52.2,73.1,94.0, 114.9, 135.8, and 156.7 feet, respectively. 

To determine how far the crown of adjacent border trees 

extended into the opening, we estimated the point at 

which the projected vertical crown edge of the border tree 

would intersect the center line of the transect, and 

measured this distance from the opening edge. These 

measurements were used to compute the portion or 

acreage of opening currently receiving direct overhead 

sunlight. In ecological literature, these openings are 

defined as extended gaps (Runkle 1990). Although the 

extended gap does not indicate the size of opening 

receiving direct sunlight from above, it is an objective and 

consistent measurement over time. 

Variables measured on each subplot included species, 

diameter at breast height (all trees larger than 2.5 inches 

d.b.h.), crown class, and the height and distance from 

border of the two tallest sample trees on each 0.01-acre 

subplot. In addition, we identified all dominant and 

codominant trees that were potential crop trees based on 

species and quality characteristics such as stem 

straightness, number of branches, sweep, crook, and 

forking. 

From these data we developed equations for each of the 

major species and/or species groups to predict total tree 

height as a function of d.b.h. Then, for each tree we used 

this predicted height, or actual height if measured, to 

predict total and merchantable cubic-foot volume using 

Demaerschalk's taper and volume functions and 

parameters (Martin 1981). Totals were summed by 

species for each subplot and corrected to horizontal 

per-acre values. Hence, stand characteristics on a peracre basis were computed for each of the 1,773 subplots. 

These included basal area, number of trees, total 

cubic-foot volume, and merchantable cubic-foot volume. 

For purposes of this study, each of the openings was 

grouped in one of five size classes: Group 1 (0.04 to 0.10 

acre); Group 2 (0.11 to 0.30 acre); Group 3 (0.31 to 0.50 

acre; Group 4 (0.51 to 1 .OO acre); Group 5 (1 .O1 to 1.75 

acres). A sixth group consisted of subplots that were 

established in clearcuts that were larger than 3 acres and 

where all the subplots were at least 150 feet from the 

border trees. Thus, the subplots in Group 6 are 

representative of stands that would develop in large 

clearcuts used in even-age management. Border trees 

should have little or no effect on Group 6 subplots. Table 2 

shows the distribution of 1,773 subplots by opening size 

and distance from border or the subplot position. 

The stand characteristics cited previously were computed 

for each opening on a per-acre basis using a weighting 

procedure commonly used in stratified random-sampling 

procedures. The mean transect length of each opening, 

after correcting for slope, was used to compute the total 

acreage in each opening. Since we knew the distance 

from border for each subplot, it was easy to compute the 

strata area or proportion of opening area to be used in the 

strata weighting procedure. Small openings have a much 

greater proportion of their total area affected by border 

trees than large openings. For example, about 78 percent 

of the area of a 0.10-acre opening is within 20 feet 

(approximately the width of one subplot) of the border. By 

contrast, only 15 percent of a 5-acre opening is within 20 

feet of the border trees (Table 3). Therefore, when stand 

characteristics are expressed on a per-acre basis for the 

entire opening, it is essential that strata means represent 

the correct proportional area of the opening as given here. 

Results and Discussion 

Species Number and Relative Frequency 

On the 1,310 subplots within openings we recorded 5,327 

stems larger than 2.5 inches d.b.h. These stems 

represented 45 tree or shrub species. On the border 

(subplots 1) we found 40 species, 35 of which also were 

found on the interior plots. The 463 subplots on the 

border had a total of 2,134 stems, approximately 460 

stems per acre, compared with about 407 stems per acre 

in the openings. The 50 different species found in all plots 

are listed in Appendix Table 11, by common and scientific 

name, shade-tolerance class, and desirability for timber 
Table 3.-Percer'age of opening area contained In border zones that are 10,20,30, or 40 feet wide. 

Opening Proportion of area in border zone for width of: 

diameter Opening 

(feet) area 10 feet 20 feet 30 feet 40 feet 

Acres 

50 0.04 0.64 0.96 - - 

75 0.10 .46 .78 0.96 - 

100 0.18 .36 .64 -84 0.96 

118 0.25 .31 .56 .76 .90 

1 50 0.41 .25 .46 .64 .78 

166 0.50 .23 .42 .59 .73 

200 0.72 .19 .36 .51 .64 

236 1 .OO .16 .31 .44 .56 

250 1.13 .15 .29 .42 54 

300 1.62 .13 .25 .36 .46 

333 2.00 .12 .23 .33 .28 

400 2.88 .10 .19 .28 .36 

500 4.51 .08 .15 .23 .29 

527 5.00 .07 .13 .21 .28 

'P = (4w/d)*(l-wld) only if w<d/2 

where P = proportion of total area in border zone of width (w, in feet) for circular openings with diameter (d, in feet). 

products. Assignment to a tolerance class was based on 

the classification of Trimble (1975). The classification of 

desirability for timber products depends on local markets, 

so it is subjective and indicates our preferences. If other 

resource uses are considered, no doubt this classification 

would change. 

The 50 species that were found were not of equal 

importance or relative frequency. In Appendix Table 12, 

we show the relative frequency of the 33 most common 

species tabulated by shade-tolerance class and 

desirability for timber products. There were only 20 

species with a relative frequency greater than 1 percent; 

however, these species combined accounted for about 90 

percent of all stems. Maple species were most 

numerous, accounting for about 26 percent of all stems, 

followed by yellow-poplar with 15 percent. All oaks 

combined accounted for about 14 percent of the stems, 

but white and chestnut oak accounted for two-thirds of all 

oak. Other common timber species each with about 3 to 

5 percent of the total were black cherry, hickory, sweet 

birch, and hemlock. Sassafras and dogwood each 

represented about 5 percent of the total. 

Effect of Site Quali and 

Study Location on 9 pecies Composition 

Species relative frequency varied considerably both at a 

study location and between locations. At a given study 

location, some of the variation in species composition 

between openings is related to differences in site quality 

as well as in opening size and site-preparation treatment. 

However, we found important differences in species 

composition between study locations particularly for the 

Illinois and West Virginia plots. For example, maples 

were most abundant on the West Virginia subplots: 68 

percent of the subplots had one or more maple stems 

while yellow-poplar was found only on 13 percent of the 

subplots (Table 4). By contrast, maples were not a major 

stand component in Illinois but yellow-poplar was the 

most abundant species, occurring on 43 percent of the 

subplots. Magnolias and birches were more abundant at 

the eastern locations while hemlock was found mostly on 

the better sites in Kentucky. Yellow-poplar, oak, and 

hickory generally were distributed more widely and found 

at all locations, but these species seemed to be 

influenced by site conditions at each location. Maple 

ranked either first or second in number of stems at every 

location except Illinois. Red maple dominated the fair 

sites and sugar maple dominated the good sites. 

Yellow-poplar was distributed widely, ranking first at 

Baldrock and in Illinois and no lower than fifth at any 

location. Sourwood was found at every location in 

considerable numbers. Sassafras was distributed widely 

and at the Fernow and Kaskaskia locations was found on 

a quarter to a third of the sample subplots. 

The influence of site quality is evident in the number of 

stems per acre for five species groups at each location 

(Table 5). We consistently found more oaks and hickories 

on the fair sites at all locations, but, as noted in Table 4, 

the overall distribution of oak and hickories varied with 

location. Also as expected, we found more yellow-poplar 

on the better sites at each location. Similar trends for 

oak-hickory and yellow-poplar were reported for the oak 

type for other harvest cutting practices (Hilt 1985; 

Heiligmann et al. 1985). 

Although maples were the most abundant species in the 

openings, they are of lesser importance in terms of stand 

characteristics such as basal area and cubic or 
Table 4.-Percentage of subplots stocked with a species at each study location 

Baldrock Robinson Vinton Furnace Fernow Kas kas kia 

Species Percent Species Percent Species Percent Species Percent Species Percent 

Y.-poplar .561 Maple sp ,598 Maple sp. .457 Maple sp. .677 Y.-poplar .425 

Maple sp. .447 Ch. oak ,221 Hickory .381 81. cherry .284 Wh. oak .349 

Hemlock .273 Wh. oak .218 Dogwood ,262 Sassafras .225 Sassafras .336 

Magnolia .229 Hickory .203 Y.-poplar ,257 Birch sp. .207 BI. gum .240 

Sourwood .202 Y.-poplar .I88 Ch. oak .I95 Y.-poplar ,126 Hickory .I64 

Birch .I82 Redbud .I66 Wh. oak .I67 BI. locust .066 S. red oak .I51 

Dogwood .I78 Sourwood .I40 Sourwood .I33 Magnolia .066 Sourwood .I37 

Wh. oak .I23 BI. cherry .I03 BI. oak ,081 Dogwood .063 Maple sp. ,116 

Beech .I11 Ash .085 N. red oak ,071 Sourwood .057 BI. cherry ,048 

Sassafras .059 BI. gum .063 BI. cherry ,067 Ch. oak .057 Scarlet oak .041 

Holly .047 BI. oak .059 BI. gum ,067 BI. gum .051 Am. beech .021 

Scarlet oak ,048 Elm sp. .052 

Table 5.-Number of trees, basal area (ft2), and quadratic mean diameter (QSD) per acre by location, site class, 

and species group 

Oak-hickory Yellow-poplar Maple Other timber Nontimber Total 

Location Fair" ~ood~ Fair Good Fair Good Fair Good Fair Good Fair Good 

KY Trees 115 27 41 148 139 65 41 160 62 122 398 522 

BA 24.2 2.8 13.3 23.3 20.0 8.0 6.9 23.8 5.2 12.1 69.6 70.0 

QSD 6.2 4.4 7.7 5.4 5.1 4.8 5.6 5.2 3.9 4.3 5.7 5.0 

OH Trees 158 81 28 54 88 91 40 48 74 64 388 388 

BA 21.6 10.4 4.6 19.5 15.2 19.2 6.2 6.6 5.4 9.1 53.0 64.8 

QSD 5.0 4.9 5.5 8.1 5.6 6.2 5.3 5.0 3.7 5.1 5.0 5.9 

WV Trees 31 1 3 53 142 145 149 136 121 18 446 343 

B A 7.7 0.3 0.7 13.5 25.6 18.6 26.9 20.7 13.7 1.3 74.6 54.4 

QSD 6.7 7.4 6.5 6.8 5.7 4.8 5.8 5.3 4.6 3.6 5.5 5.4 

IL Trees 204 66 19 112 - 31 42 54 106 72 371 335 

B A 19.0 5.7 3.1 26.8 - 3.7 2.0 11.5 6.0 4.4 30.0 52.1 

QSD 4.1 4.0 5.5 6.6 - 4.7 3.0 6.2 3.2 3.3 3.9 5.3 

Average Trees 108 35 27 99 120 86 68 113 83 74 406 409 

B A 19.0 3.8 7.5 20.5 19.1 12.0 11.7 18.0 7.5 7.1 64.8 61.4 

QSD 5.7 4.5 7.1 6.2 5.4 5.1 5.6 5.4 4.1 4.2 5.4 5.3 

"Black oak site index 56 to 65. 

b~lack oak site index 66 to 75. 

merchantable volume. Yellow-poplar constitutes 15 

percent of the number of trees (Appendix Table 12), but 

accounts for 21 percent of the basal area and 37 percent 

of the merchantable volume. By contrast, 24 percent of 

the trees are red maple and they represent 23 percent of 

the basal area and 23 percent of the merchantable 

volume. Basal area and merchantable volume are not 

illustrated for individual species; however, they are 

included in Figure 3, which provides totals by tolerance 

class and timber class. Overall, there were slightly more 

tolerant stems than intolerant ones (45 versus 39 percent) 

(Fig. 3). However, the intolerant preferred species were 

about equal to tolerant nonpreferred species in basal 

area, and the intolerant preferred species represented the 

largest proportion of the stand merchantable cubic volume. 

Over all locations, basal area on fair sites was about five 

times greater than on good sites for the oak-hickory group 

(Table 5). Basal area of yellow-poplar at each location 

was consistently higher on the better sites. The basal 

area of maple varied because red maple was found 

mostly on fair sites and sugar maple mostly on good sites. 

In general, the quadratic mean diameter of the 

oak-hickory group was larger than that of the maple group 

on fair sites but on good sites the reverse generally was 

true except in West Virginia, where there were few oaks 
- 

intolerants Intermediates Tolerants 

Nonpreferred 

Timber 

Intolerants Intermediates Tolerants 
Table 6.-Per acre-stand characteristics by size opening (group) 

- 

Size Number Basal Total Merchantable 

opening of trees area volume volume 

(acres) .- 

~tl -- --------- ,q 3 ----- ---- -- 

6 (>3.0) 51 9.6a 92.0a 2,467a 884a 

5 (1.1 -1 .8) 393.6bc 67.0b 1,790b 630ab 

4 (0.51 -1 .O) 443.9ab 64.8b 1,770b 545bc 

3 (0.31 -0.50) 358.8bc 49.8~ 1,280~ 406cd 

2 (0.1 1-0.30) 344.6~ 38.2~ 893d 225de 

1 (0.0-0.1 0) 241.6d 18.0d 356e 52e -- 

Values in the same column with different letters are significantly different at 

on good sites (Table 5). Yellow-poplar was consistently 

larger than oaks on both fair and good sites. Again, the 

exception was in West Virginia, where few yellow-poplar 

were found on fair sites. 

Effect of Opening Size on Stand Characteristics 

The effect of opening size is obvious from the results 

presented in Table 6. Mean basal area per acre ranged 

from 67 ft2 for the larger openings to 18 ft2 for the smallest 

opening. Larger openings (Group 6) had 92 ft2 per acre. 

Total volume followed similar trends as 2,467 ft3 per acre 

were recorded for Group 6 openings compared with only 

356 ft3 per acre for openings of 0.10 acre (Group 1). 

Per-acre values for Group 6 subplots were not adjusted 

because the proportion of acreage that is affected by 

border trees is insignificant compared to the total acreage 

in these large clearcuts. Statistical analysis (ANOVA) of 

the results indicate that opening size significantly (P < 

0.05) affects number of trees, basal area, and cubic 

volumes per acre. In fact, as Table 6 indicates, there 

were significant differences between several of the size 

groups. Note that all stand characteristics increase with 

opening size except for the anomaly in number of trees 

between opening size 4 and 5. Because the stand 

characteristics were so highly correlated with opening 

size, we used nonlinear regression techniques to predict 

number of trees, basal area, total cubic-foot volume, and 

merchantable cubic volume as a function of opening size 

(Fig. 4). The computed regression parameters shown in 

Figure 4 include all of the subplots from Group 6, though 

the latter are not shown on the graphs. These equations 

show a considerable difference in predicted basal area 

(55 versus 72 ft2) for 0.5-acre versus I .O-acre openings. 

The difference in predicted merchantable cubic volumesfor 

openings of this size is even greater, 452 versus 651 ft . 

Effect of Opening Size on Species Composition 

The stand values given in Table 6 are broken down by 

desirability for timber products and also expressed as a 

percentage (Appendix Table 13). These values by 

opening size also are broken down by shade-tolerance 

class and percentage (Appendix Table 14). Although 

there is a larger proportion of tolerant species on the 

smallest opening (< 0.1 acre), the proportion of 

shade-tolerant stems versus intolerant ones remains 

about the same for openings larger than 0.1 acre. The 

effect of opening size on growth is clear from the volumes 

in Appendix Tables 13 and 14, which indicate that the 

amount of basal area and stand volume increases rapidly 

with opening size. 

Not only did size of opening affect the stand 

characteristics but there was an interaction between 

opening size and distance from the border. The stand 

values shown in Table 7 indicate that distance from the 

border has a greater effect on small openings than on 

larger openings. For example, the mean basal area for all 

subplots in position 2 (within 20.9 feet of the borfer) for 

the smallest openings was only 20 percent (21 ft ) per 

acre compared with 43 percent (45 ft2) per acre for the 

same position on openings between 1.0 and 1.75 acres 

(Group 5). From the results in Table 7, it appears that this 

interaction effect is minimized as opening size increases 

beyond an acre. It also is apparent that the distance from 

the edge affects stand characteristics for at least a 

distance of 100 feet into the opening. The values shown 

in Table 7 should be interpreted with caution where sample 

size is fewer than 10 observations per cell (Table 2). The 

stand values for large clearcuts were based on all of the 

subplots from the large clearcuts (> 3 acres) plus all 

subplots that were 105 feet or more from the opening 

border. 

The effect of opening size and distance from the edge on 

growth and species composition is readily apparent in 

Figures 5 through 8. These figures show the number of 

trees, basal area, total volume, and merchantable volume 

on a per-acre basis by tolerance class and distance from 

the edge for each size group. 
Total Volume 

Y = 195.390 + 2017.229 '(lap (-1.972 ' X)) 

h 

0 

E 2500 

Number of Trees 

0 0.5 1 1.5 2 

Opening Size (acres) 

000- 

7w:''~-~'''~1'~~'1'"T: 

- 

0 0.5 1 1.5 2 

Opening Size (acres) 

Basal Area 

Merchantable Volume 

,100 

CV 

E 

. .. - 

- 

125~"""""""""'- 

: - 

1 OO 

0 0.5 1 1.5 2 

Opening Size (acres) 

-. . 

- 

Y = 14.169 + 69.238 '(1 -8~ (-1.774 ' X)) 1 - Y = 229.946 + 238.1 71 '(1 -exp (-2.21 4' X)) - . adj. R2 = 0.435 

o-...ml....l....l.a..' 

n 

CQ 

E- 1200- 

2 - 

900 

3 

(~i~ure 4.--Effect of opening size on stand characteristics (data for opening Group 6 are not included). 

0 0.5 1 1.5 2 

Opening Size (acres) 

Y = -2.793 + 809.929 '(1-exp (-1.648 * X)) 

adj. R2 = 0.685 

- 

- 

-. - 

- 
Table 7-Percentage of trees, basal area, merchantable cubic volume, and total cubic volume, by 

opening size and distance from border (edge) compared to interior of large clearcots 

Distance Size of opening 

from edge 

(feet) 0.0-0.1 0.1 -0.3 0.3-0.5 0.5-1 .O 1 .O-2.0 

acre acre acre acre acre 

TreedAcres 

2 1 48 54 57 66 58 

42 87 75 91 79 

63 78 88 83 

84 89 84 

105 77 

Basal AreaIAcre 

2 1 32 38 42 43 

42 47 58 67 68 

63 67 80 80 

84 101 93 

105 88 

Merchantable Cubic Volume/AcreC 

2 1 19 27 21 27 

42 22 46 42 62 

63 59 73 68 

84 1 32 95 

105 107 

Total Cubic Volurne/Acred 

2 1 26 32 34 35 

42 36 5 1 59 6 1 

63 60 78 71 

84 107 87 

105 92 

'557 for large clearcut (> 3.0 acres). 

bl 05 ff for large clearcut. 

C1 ,113 ft3for large clearcut. 

*3,124 R3 for large clearcut. 
Opening Group I (0.0 - 0.1 acre) 

T------ 

10.4 

Mean Distance (fl.) from 

Edge of Opening 

mm 

Opening Gmup 3 (0.3 - 0.5 acre) 

10.4 31.3 52.2 

Mean Distance (ft.) from 

Edge of Opening 

m1 

Opening Group 5 (1 .O - 2.0 acres) 

2 200 w 

C 

2 

9 

. 

I 

,g loo 

0 

Mean Distance (fl.) from 

Edge of Opening 

Opening Group 2 (0.1 - 0.3 acre) I 1 

Mean Distance (ft.) from 

Edge of Opening 

mm 

Opening Group 4 (0.5 - 1 .O acre) 

Mean Distance (ft.) from 

Edge of Opening 

Tolerance Class 

a Shade Tolerant 

Intermediate 

Shade Intolerant 

Figure 5.-Variation in trees per acre by subplot position and tolerance class. 
Opening Group 1 (0.0 - 0 1 acre) 

a 

I ~ 

Mean Distance (ft) from 

Edge of Opening 

Opening Group 3 (0.3 - 0.5 acre) 

a/- - 

Mean Distance (ft) tom 

Edge of Opening 

Mean Distance (fl) from 

Edge of Opening 

Opening Group 5 (I .O - 2.0 acres) 

Open~ng Group 2 ( 0 1 - 0 3 acre) 7- -1 --- 1 

a 

Mean Distance (ft) from 

Edge of Opening 

I I I I 1 

I 

Opening Group 4 ( 0.5 - 1 .O acre) .- - 

Mean Distance (ft) from 

Edge of Opening 

Tolerance Class 

Shade Tolerant 

Intermediate 

a Shade Intolerant 

Figure 6.-Variation in basal area per acre by subplot position and tolerance class. 
Opening Group 1 (0.0 - 0.1 acre) 

Mean Distance (ft) from 

Edge of Opening 

Opening Group 3 (0.3 - 0.5 acre) 

10.4 31.3 52.2 

Mean Distance (ft) from 

Edge of Opening 

Opening Group 5 (1 .O - 2.0 acres) 

Mean Distance (ft) from 

Edge of Opening 

Opening Group 2 (0.1 - 0.3 acre) r 

Mean Distance (ft) from 

Edge of Opening 

Opening Group 4 (0.5 - 1 .O acre) 

10.4 31.3 52.2 73.1 94.0 

Mean Distance (ft) from 

Edge of Opening 

Tolerance Class 

a Shade Tolerant 

Intermediate 

Shade Intolerant 

Figure 7.-Variation in total volume cubic foot volume by subplot position and tolerance class. 
Opening Group 1 (0.0 - 0.1 acre) 

lgal 

Mean Distance (R) from 

Edge of Opening 

Opening Group 3 (0.3 - 0.5 acre) 

Fi 

E. 

10.4 31.3 52.2 

Mean Distance (R) from 

Edge of Opening 

Opening Group 5 (1 .O - 2.0 acres) 

18001 I I I I 

I 

Mean Distance (R) from 

Edge of Opening 

Opening Group 2 (0.1 - 0.3 acre) 

3 

Mean Distance (R) from 

Edge of Opening 

Opening Group 4 (0.5 - 1 .O acre) 

1800l 

Mean Distance (R) from 

Edge of Opening 

Tolerance Class 

a Shade Tolerant 

Intermediate 

Shade Intolerant 

Figure 8.-Variation in merchantable volume by subplot position and tolerance class. 

14 
Table 8.-Number of crop trees per acre by site, opening size, and position in opening (spacing 

between trees was not a consideration) 

Opening Opening Site Subplot position 

group size class 2345 6 7 8 9 Mean 

Acres 

1 0.0-0.1 Fair 4 - 4 

Good 5 - 5 

2 0.1 -0.3 Fair 19 38 - 26 

Good 17 22 - 18 

3 0.3-0.5 Fair 11 16 7 - 12 

Good - 20 11 - 10 

4 0.5-1 .O Fair 12 37 37 84 100 - 35 

Good - 64 78 100 40 100 55 

5 1 .O-1 .8 Fair 13 22 23 45 37 25 - 26 

Good 12 35 71 60 120 164 87 77 

6 >3.0 Fair ---- - 50 69 56 58 

Good ---- - 75 88 88 84 

Weighted means Fair 12 27 27 59 42 43 69 56 27 

Good 9 42 56 68 118 127 105 82 46 

Crop trees. Available data on crop trees were 

summarized by site quality, opening size, and opening 

sample position (Table 8). All crop trees were in the 

codominant crown class and were selected primarily on 

the basis of "timber" criteria. Included are trees with 

vigorous growth characteristics and a potential high 

quality such as straight stems with few bole branches and 

no forks or other major defects. Although the best trees 

were selected for crop trees, other good stems with 

potential as crop trees were present in the openings. 

Small openings had few crop trees (about 5 per acre) on 

both good and fair sites. When opening size was at least 

0.5 to 1 acre, the number of crop trees per acre averaged 

55 on good sites and 35 on fair sites. Likewise, for 

openings greater than 3 acres, there were more than 80 

crop trees per acre on the good sites compared with 

about 60 on fair sites. 

Characteristics of the individual crop trees, d.b.h., and 

total height were summarized by species group, opening 

size, and site class (Table 9). Some crop trees on the fair 

sites are bigger than those on the better growing sites. 

For example, the average height of oak crop trees on a 

fair site (opening 5) was 62.6 feet, while oak crop trees on 

the good site averaged 56.0 feet. An explanation could 

be that crop trees of sprout origin were a greater factor 

on fair than on good sites. Also, the fair sites may be 

more productive than the initial site class indicates. 

Another factor in differences in total height could be the 

age difference among trees on various plots and 

locations. 

The edge effect as well as opening size and site 

influenced the presence of crop trees. In general, as the 

number of subplots increased from the opening edge 

toward the center of the opening, so did the number of 

potential crop trees (Table 8). Likewise, number of crop 

trees was consistently higher within a subplot for the good 

compared with the fair sites. This trend was more 

pronounced as the opening size increased. 
Tabk 9.--Crop tree d.b.h and height by opening size, site class, and species group 

Opening Opening Site Oak-hickory Yellow-poplar Maples Others All species 

group size class 

D.b.h. Height D.b.h. Height D.b.h. Height D.b.h. Height D.b.h. Height 

Acres Inches Feet Inches Feet Inches Feet Inches Feet Inches Feet 

1 0.0-0.1 Fair 5.4 44 5.4 44 

Good 9.9 72 9.9 72 

2 0.1-0.3 Fair 7.9 64.5 5.8 50.2 8.4 57.7 7.1 55.3 

Good 4.9 45 7.1 56.8 4.5 49 6.3 54.8 

3 0.3-0.5 Fair 8.8 72.2 6.8 59 5.6 55.3 6.2 44.5 7 57.2 

Good 10.4 73.8 8.2 58 9.9 69.9 

4 0.5-1.0 Fair 8.1 60.6 7.7 67.9 6.3 59.4 7.5 64 

Good 6.7 68.2 4.7 56 8.6 64.6 6.9 68.3 

5 1 .O-1.8 Fair 10.3 62.6 10.3 74.1 8.6 63.9 7.7 60 8.9 65.4 

Good 6.9 56 6.8 65.9 6.9 59.9 8 61 7.2 63.3 

6 >3.0 Fair 7.1 68 13.1 81.7 10.8 78 11 74.2 11.6 77 

Good 7 57.6 6.9 62.3 4.6 53 8.6 61.5 6.9 60.3 
Summary 

Approximately 30 years ago, a series of studies was 

installed in central hardwood forests to evaluate the 

effects of opening size on species composition and 

stem development of new stands. Study areas were 

located on five experimental forests-Kaskaskia in 

Illinois, Robinson and Baldrock in Kentucky, Vinton in 

Ohio, and the Fernow in West Virginia. The Robinson is 

administered by the University of Kentucky and the 

others are maintained by the USDA Forest Service. 

Sites ranged from fair to good and opening sizes ranged 

from 0.04 to 1.61 acres. The following are results of a 

survey of 89 openings. 

In all openings combined, there were 45 different 

woody species. Twenty species accounted for 90 

percent of these stems. Maples, oak, hickory, and 

yellow-poplar represented 68 percent of all stems. 

Differences in species composition and growth rate 

were related to site quality. There were more oaks and 

red maples on fair sites while yellow-poplar and sugar 

maple dominated the good growing sites. 

Effects of distance from the opening edge varied 

greatly with opening size. For example, for subplots 

with a midpoint of 31.3 feet from the edge, stand 

volume was about three times as large on 1- to 2-acre 

openings as on 0.1- to 0.3-acre openings. 

Opening size had a tremendous effect on stand 

productivity. At least for about the first 30 years (short 

time), four to five times as much basal area and 

volume per acre can be expected on openings of at 

least 1.0 acre compared with those of 0.1 acre. 

There was a higher portion of shade-tolerant species in 

small openings, particularly on those of less than 0.1 

acre. 

Reduction in stand growth on smaller openings was 

attributed to the effect of the border zone (edge) where 

numbers of trees as well as height and d.b.h. were 

reduced. 

The greatest reduction was in growth of trees nearest 

the opening border. However, some effect on growth 

extended at least 100 feet into the opening. 

There was a strong interaction between border effect 

and opening size. Growth was greater at a given 

distance from the border for larger openings. 

As opening size increased at least up to 1 acre, the 

proportion of shade-intolerant species increased. 

However, the largest effect of opening size was the 

increase in total merchantable volume of intolerants as 

opening size increased. 

Equations were presented for predicting number of 

trees, basal area, merchantable volume, and total 

cubic-foot volume for openings up to 2.0 acres in size. 

As opening size increased, the increase in stand 

volume and basal area was greater for the shade 

intolerants (yellow-poplar) than the intermediates 

(oaks-hickories). 

Openings of 0.1 acre or less averaged about five crop 

trees per acre. Openings of 0.5 to 1.0 acre averaged 

55 crop trees per acre on good sites and 35 per acre 

on fair sites. Openings larger than 3 acres averaged 

88 crop trees per acre on the better sites versus 55 on 

the fair sites. 

Distance from opening edge as well as opening size 

and site influenced the presence of crop trees. 

Generally, the number of crop trees increased from the 

opening edge toward the opening center, and there 

were more crop trees on good versus fair site. This 

trend increased with an increase in opening size. 

Depending on management objectives, size of clearcut 

opening has a major influence on future stand 

characteristics. Species composition, species diversity, 

productivity, availability of crop trees, available habitat, 

and edge effects can be manipulated by using openings of 

different sizes. 

Information from this study is based on clearcut openings 

that were around 30 years old. These new even-aged 

stands were well established, so there are limited 

opportunities to manipulate species composition other 

than using timber stand improvement and crop-tree 

thinning techniques. Results show that the initial size of a 

clearcut opening has a major influence on stand 

development. Thus, users need to be aware of these 

effects to satisfy individual forest management objectives. 

This information should be important to forest managers 

who are considering small openings as viable alternatives 

to clearcutting. Forest managers and landowners also 

need to be aware of stand development and productivity 

related to opening size. More informed decisions should 

be possible using this report and related publications to 

improve the management techniques in central hardwood 

forests. 

Acknowledgments 

We gratefully acknowledge the efforts of Ivan Sander and 

Russ Waiters in designing the methodology to collect and 

record the study data. John Beaton, Robert Ford, Robert 

Baughman, and Randy Vermell helped collect andlor input 

the data for computer analyses and summaries. We also 

thank members of the Northeast Stand Establishment 

Working Group as well as many others for identifying the 

need for and helping facilitate this research. 
Literature Cited 

Heiligman, Randall B.; Norland, E. R.; Hilt, D. E. 1985. 

28-year-old reproduction on five cuttlng practices 

in upland oak. Northern Journal of Applied Forestry. 

2(1): 17-22, 

Hill, Deborah B. 1987. Oak-hickory regeneration In 

eastern Kentucky. In: Hay Ronald L.; Woods, Frank 

W.; DeSelm, Hal, eds. Proceedings, 6th central 

hardwood forest conference; 1987 February 24-26; 

Knoxville, TN. Knoxville, TN: University of Tennessee: 

111-118. 

Hilt, Donald E. 1985. Species composition of young 

central hardwood stands that develop after 

clearcutting. In: Dawson, Jeffrey 0.; Majerus, 

Kimberly A., eds. Proceedings, 5th central hardwood 

conference; 1985 April 15-1 7; Urbana, IL. UrbanaChampaign, IL: University of Illinois: 11 -1 4. 

Martin, A. Jeff. 1981. Taper and volume equations for 

selected Appalachlan hardwood specles. Res. Pap. 

NE-490. Broomall, PA: U.S. Department of Agriculture, 

Forest Service, Northeastern Forest Experiment 

Station. 22 p. 

Marquis, David A. 1965. Controlling light in small 

clearcuttlngs. Res. Pap. NE-39. Upper Darby, PA: 

US. Department of Agriculture, Forest Service, 

Northeastern Forest Experiment Station. 16 p. 

Minckler, Leon S.; Woerheide, John D. 1965. 

Reproduction of hardwoods 10 years after cuttlng 

as affected by site and openlng slze. Journal of 

Forestry. 63(2): 103-107. 

Minckler, Leon S.; Woerheide, John D.; Schlesinger, 

Richard C. 1973. Light, soil moisture, and tree 

reproduction in hardwood forest openings. Res. 

Pap. NC-89. St. Paul, MN: U.S. Department of 

Agriculture, Forest Service, North Central Forest 

Experiment Station. 6 p. 

Runkle, J.R. 1990. Gap dynamics in an Ohlo AcerFagus forest and speculatlons on the geography of 

disturbance. Canadian Journal of Forest Research. 

20: 632-641. 

Sander, Ivan L.; Clark, F. Bryan. 1971. Reproduction of 

upland hardwood forests in the Central States. 

Agric. Handb. 405. Washington, DC: U.S. Department 

of Agriculture. 25 p. 

Smith, H. Clay. 1981. Diameters of clearcut openings 

Influence central Appalachlan hardwood stem 

development-a 10-year study. Res. Pap. NE-476. 

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

Service, Northeastern Forest Experiment Station. 8 p. 

Trimble, George R., Jr. 1975. Summaries of some 

sllvical characterlstlcs of several Appalachlan 

hardwood trees. Gen. Tech. Rep. NE-16. Upper 

Darby, PA: US. Department of Agriculture, Forest 

Service, Northeastern Forest Experiment Station. 5 p. 

Walters, Russell S.; Nyland, Ralph D. 1989. Clearcuttlng 

central New York northern hardwood stands. 

Northern Journal of Applied Forestry. 6(2): 75-78. 

Willison, Gary L. 1981. Natural regeneration twenty 

years after clearcutting as affected by slte and slze 

of openlng in southeast Ohlo. Columbus, OH: Ohio 

State University. 60 p. M.S. thesis. 
Appendix 

Table 10.-Distribution of sample openings by location, site, and opening size 

Opening size 

Site 

Baldrock Fair - - - 2 - - 2 

Good - 3 - 3 4 2 12 

Robinson Fair 6 - 3 3 3 - 15 

Good - - - - - - - 

Vinton Fair - 3 3 3 2 3 14 

Good - - - - 1 - 1 

Parsons Fair 7 3 - 3 2 15 

Good 6 - 3 - 3 2 14 

Kaskaskia Fair 2 3 1 - - - 6 

Good 3 5 1 1 - - 10 

Total Fair 15 6 10 8 8 5 52 

Good 9 8 4 4 8 4 37 

Table 11.-List of species and assigned class for shade tolerance and desirability for timber products 

Common name Scientific name Shade Desirability 

tolerancea for timbeP 

Sugar maple 

Red maple 

Ohio buckeye 

Serviceberry 

Paw paw 

Yellow birch 

Sweet birch 

Hornbeam 

Hickory 

Hackberry 

Eastern redbud 

Flowering dogwood 

Hazelnutlwitch hazel 

Persimmon 

Beech 

Ash 

Holly 

Black walnut 

Sweetgum 

Yellow-poplar 

Cucumbertree 

Fraser magnolia 

Magnolia 

Blackgum 

Hophornbeam 

Sourwood 

Shortleaf pine 

Pitch pine 

Virginia pine 

Acer saccharum Marsh 

Acer rubrum L. 

Aesculus glabra Wild. 

Amelanchier arborea (Michx. F.) Fern. 

Asimina triloba (L.) Dunal 

Betula alleghaniensis Britton 

Betula lenta L. 

Carpinus carolinians Walt. 

Carya sp. 

Celtis occidentalis L. 

Cercis canadensis L. 

Cornus florida L. 

Corylus sp.lHamamelis sp. 

Diospyros vi~iniana L. 

Fagus grandifolia Ehrh. 

Fraxinus sp. 

llex opaca Ait. 

Juglans nigra L. 

Liquidambar styraciflua L. 

Liriodendron tulipifera L. 

Macnolia acuminata L. 

Magnolia fraseri Walt. 

Magnolia sp. 

Nyssa sylvatica Marsh. var. sylvatica 

Ostrya virginiana (Mill.) K.Koch. 

Oxydendrum arboreum (L.) DC. 

Pinus echinata Mill. 

Pinus rigida Mill. 

Pinus virginiana Mill. 

Continued 
Table 11 .-Continued 

Common name Scientific name Shade Desirability 

tolerancee for timbeh 

Sycamore Platanus occidentalis L. 1 2 

Bigtooth aspen Populus grandidentata Michx. 

Black cherry Prunus serotina Ehrh. 

White oak Quercus alba L. 

Scarlet oak Quercus coccinea Muenchh. 

Southern red oak Quercus falcata Michx. var. falcata 

Burr oak Quercus macrocarpa Michx. 

Chestnut oak Quercus prinus L. 

Northern red oak Quercus rubra L. 

Post oak Quercus stellata Wangenh. 

Black oak Quercus velutina Lam. 

Sumac Rhus sp. 

Black locust Robinia pseudoacacia L. 

Sassafras Sassafras albidum (Nutt.) Nees 

Basswood Tila americana L. 

Eastern hemlock Tsuga canadensis (L.) Carr. 

American elm Ulmus americana L. 

Red elm Ulmus rubra Muhl. 

Misc. shrubs 

Misc. trees 

'1 = shade intolerant; 2 =somewhat shade tolerant; 3 = shade tolerant. 

bl = preferred; 2 = nonpreferred; 3 = others. 

Table 12.-Most common specles and their relative frequency by shade 

tolerance and deslrablllty for timber products 

Intolerant Intermediate Tolerant 

PREFERRED 

Yellow-poplar .I48 White oak .051 Sugar maple .017 

Black cherry .049 Chestnut oak .045 

White ash .013 Black oak .010 

Scarlet oak .O10 N, red oak .009 

S. red oak .010 

NONPREFERRED 

Hickory .047 Red elm .004 Red maple .240 

Sweet birch .043 Cucumber tree .003 Hemlock .035 

Black locust .008 American elm .001 Beech .027 

Aspen .003 Yellow birch .001 Blackgum .025 

Virginia pine .002 Basswood .003 

OTHER 

Sassafras .053 Fraser Magnolia ,025 Dogwood .050 

Sumac .001 Magnolia sp. .012 Sourwood .028 

Redbud .014 

Setviceberry .005 

Holly .003 
Table 13.-Stand characteristics by opening size and desirability for timber products 

- 

Openlng Opening Timber Number Basal Total Merchantable 

group size class of trees area volume volume 

Acres Ft2 Ft3 Ft3 

1 0.0-0.1 Preferred 63 (26)" 6.7 (37) 139 (39) 35 (67) 

Nonpreferred 11 1 (46) 7.5 (42) 160 (45) 15 (29) 

Other 68 (28) 3.8 (21) 57 (16) 2 (4) 

2 0.1 -0.3 Preferred 145 (42) 21.4 (56) 545 (61) 189 (84) 

Nonpreferred 90 (26) 8.8 (23) 196 (22) 27 (12) 

Other 1 10 (32) 8.0 (21) 152 (1 7) 9 (4) 

3 0.3-0.5 Preferred 136 (38) 24.4 (49) 666 (52) 260 (64) 

Nonpreferred 154 (43) 20.4 (41) 512 (40) 138 (34) 

Other 69 (19) 5.0 (10) 102 (8) 8 (2) 

4 0.5-1 .O Preferred 162 (41) 32.4 (50) 956 (54) 354 (65) 

Nonpreferred 161 (41) 25.3 (39) 673 (38) I69 (31) 

Other 71 (18) 7.1 (11) 141 (8) 22 (4) 

5 1 .O-1.8 Preferred 142 (32) 29.5 (44) 877 (49) 391 (62) 

Nonpreferred 21 3 (48) 28.8 (43) 716 (40) 195 (31) 

Other 89 (20) 8.7 (13) 197 (11) 44 (7) 

6 >3.0 Preferred 187 (36) 44.2 (48) 1283 (52) 575 (65) 

Nonpreferred 234 (45) 36.8 (40) 91 3 (37) 265 (30) 

Other 99 (19) 11.0 (12) 271 (11) 44 (5) 

"Parentheses indicate percent. 

Table 14.-Stand characteristics by opening size and shade-tolerance class 

Opening Opening Tolerance Number Basal Total Merchantable 

group size class of trees area volume volume 

Acres Ft2 Ft3 Ft3 

1 0.0-0.1 Intolerant 58 (24)A 4 (24) 96 (27) 17 (33) 

Intermediate 48 (20) 4 (28) 93 (26) 18 (35) 

Tolerant 135 (56) 10 (48) 167 (47) 17 (32) 

2 0.1 -0.3 Intolerant 145 (42) 18 (46) 429 (48) 139 (62) 

Intermediate 69 (20) 8 (22) 196 (22) 43 (19) 

Tolerant 1 3 1 (33) 12 (32) 268 (30) 43 (19) 

3 0.3-0.5 Intolerant 151 (42) 21 (43) 551 (43) 187 (46) 

Intermediate 57 (16) 10 (21) 269 (21) 85 (21) 

Tolerant 151 (42) 18 (36) 461 (36) 134 (33) 

4 0.5-1 .O Intolerant 130 (33) 25 (38) 743 (42) 311 (57) 

Intermediate 83 (21) 15 (23) 389 (22) 76 (14) 

Tolerant 181 (46) 25 (39) 637 (36) 158 (29) 

5 1 .O-1.8 Intolerant 182 (41) 31 (46) 859 (48) 353 (56) 

Intermediate 58 (13) 9 (14) 251 (14) 63 (10) 

Tolerant 204 (46) 27 (40) 680 (3s) 214 (34j 

6 >3.0 Intolerant 223 (43) 43 (47) 1209 (49) 504 (57) 

Intermediate 94 (1 8) 15 (16) 394 (1 6) 97 (11) 

Tolerant 203 (39) 34 (37) 864 (35) 283 (32) 

AParentheses indicate percent. 
Dale, Martin E.; Smith, H. Clay; Pearcy, Jeffrey N. 1995. Size of clearcut 

opening affects species composition, growth rate, and stand 

characteristics. Res. Pap. NE-698. Radnor, PA: U.S. Department of 

Agriculture, Forest Service, Northeastern Forest Experiment Station. 21 p. 

In the late 1950's and early 1960's, a series of studies was installed in the central 

hardwood forest to determine if size of clearcut opening affects the growth rate 

and species composition of new stands. In 1991, about 30 years after cutting, 

stand data were collected in 89 openings ranging in size from 0.04 to 1.61 acres. 

The number of stems per acre increased with opening size; however, the number 

of shade-tolerant species constituted a greater proportion of the stand in small 

openings (< 0.5 acre), while the proportion of shade-intolerant species increased 

in larger openings. Basal area and volume of the current stands increased 

markedly with opening size for openings up to at least 1 acre. Results of this 

study indicate that opening size has a major influence on stand characteristics 

after about 30 years. 

Keywords: Central hardwoods, opening size, species composition, stand 

productivity 

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