United States

Department of

Agriculture

Forest Service

Southern Forest

Experiment Station

Rezearth Note

SO-323

March 1988

Hardwood Regrowth and Yields on Bottomland Clay Soil

Following Clearcutting

Roger M. Krinard and Robert L. Johnson

SUMMARY

Five years of regrowth of a clearcut hardwood stand

on the Delta Experimental Forest in Mississippi were

evaluated to determine growth and development and

biomass yields. Dry weight mean annual increments for

years 1 through 5 following harvesting of an 1 l-year-old

hardwood stand on Sharkey clay soil were 0.6, 1.9, 2.4,

3.5, and 3.2 tons per acre per year, respectively. Tallest

trees cut during the 5 years averaged 8, 11, 13, 18, and

19 feet. Major species were green ash, Nuttall oak,

American elm, sugarberry, water hickory, and roughleaf

dogwood.

Additional keywords: Stand development, Fraxinus pennsylvanica, Ulmus americana, Celtis laevigata,

Quercus nuttallii, Carya aquatica, Cornus drummondii,

biomass, slackwater sites.

INTRODUCTION

While hardwood stands on clay soils may have site

indices 20 to 40 feet lower at age 50 than stands on

medium-textured soils, they are a significant part of the

hardwood picture. Little information is available, however, on stand growth and development and biomass

yields following clearcutting of young, even-aged stands

on slackwater sites. This note presents information on

stem numbers and development, together with aboveground biomass, after 5 years of regrowth following cutting of an 11 -year-old stand on Sharkey clay soil. The

1 l-year-old stand-its biomass was measured at harvest (Krinard and Johnson 1981)-developed after logging of an approximately 70-year-old overstory, shearing

of stumps and remaining stems, sweeping with a dozer

blade, and sowing of Nuttall oak (Quercus nuttallii

Palmer) acorns at 5- by lo-foot spacing. The stand is

located on the Delta Experimental Forest, Washington

County, MS.

METHODS

There were three replications of five regrowth periods

that developed following the harvesting of the stand.

Regrowth periods were from 1 to 5 years’ duration. Also,

plots that had been cut after years 1 through 4 were recut

again after the fifth year. Total regrowth represented

5-year sums, as follows:

1 st regrowth 2nd regrowth Total

period period regrowth

_____________________ years _____________________

1 4 l&4

2 3 2&3

3 2 3&2

4 1 4&l

5 . . . . 5

A randomized complete block design was used, with

three blocks containing five treatments (or regrowth periods) each. The blocks consisted of three rows, with a

middle measurement row and adjacent border rows, on

1 O-foot centers with 5-foot-wide mowed strips serving as

middles between rows. Mowing was done yearly during

the regrowth period. Within measurement rows, plots

were 5 by 60 feet, with the interior 30 feet being measurement plots. Border rows were cut the same as adjaSouthern Forest Experiment Station/l-102lO U.S. Postal Services Bldg., 701 Loyola Avenue, New Orleans, La. 70113

Forest Service, U.S. Department of Agriculture.

Serving Alabama, Arkansas, Louisiana, Mississippi, E. Oklahoma, Tennessee, E. Texas, Puerto Rico, U.S. Virgin Islands

1
cent measurement rows. Per acre values presented for

tree data are based on the 0.0034-acre measurement

plots.

Prior to a cutting treatment, all stems >l.O foot tall

were tallied. Information taken included species, total

height, and d.o.f. (diameter at l-foot height). Stems were

cut within 1 to 2 inches of the ground or stumps and

weighed in the field on a digital balance. For each plot,

a stem sample was taken for moisture determination.

These samples were dried to constant weight in a kiln at

104°C.

Each year, for plots not scheduled for cutting, all

sprouts occurring on the five largest stumps per plot (as

determined after the 11 -year-old stand was harvested)

were measured.

During each growing season, five of the tallest stems

per plot for each of 15 plots were measured biweekly for

evaluation of stand development.

The Friedman test (at the 0.05 level) was used in

analyzing the randomized complete block design for

stem numbers and weights for the first and second regrowth periods and for total regrowth because of heterogeneity of variance resulting from variation in plot values.

In addition to the Friedman test, a covariance analysis

was used to compare volume mean annual increments

and a partitioned polynomial was used to compare

height growth of the tallest stems.

RESULTS

When the stand was cut at age 11,21 different species

were measured. Major species, based on the ratio of

species volume to total volume (with volume equated to

C(d.o.f.)**height), were: ash (Fraxinus pennsylvanica

Marsh.) (.34), Nuttall oak (.23), elm (U/mus americana

L.) (.12), sugarberry (Celtis laevigata Willd.) (.lO), water

hickory (Carya aquatica (Michx. f.) Nutt.) (.12), and

roughleaf dogwood (Cornus drummondii C. A. Meyer)

(.04). Major species for total regrowth were: ash (.47),

Nuttall oak (.19), elm (.15), sugarberry (.04), water hickory (.05), and roughleaf dogwood (.06).

Number of stems varied greatly between plots at age

11 and for regrowth periods. However, mean stem numbers per acre at age 11 did not differ significantly by

future treatments.

The trend, in number of sprouts per stump and total

stems per acre >l .O foot in height, was for the maximum

number to develop in the growing season after cutting,

then decline in succeeding years and again increase

with recutting (table 1). An exception was that the first

year’s regrowth of treatment l&4 had fewer stems than

the second year’s regrowth of treatment 2&3, but this

Table 1 .--Trees per acre > 1.0 foot tall by treatment at age 7 1 and at

recutting(s) with standard error, where SE = SD/x6

Treatment 11 years First recutting Second recutting

1, 4 8,809 2 1,880 35,818 st 4,219 14,817 f 2,443a1

2,3 15,294 2 2,874 44,334 I 8,987 32,331 f 7,374b

3, 2 13,939 ” 1,372 30,492 + 1,844 35,622 + 7,455b

4, 1 14,520 k 3,186 25,749 f 5,547 56,725 f 10,352b

5 16,940 f 1,721 24,974 + 2,101 . . . . . . . . . . . . . . . .

‘Means appearing with same letter not significantly different within

each column at 0.05 level by the Friedman test; if no letters, overall test

was not significant.

appeared to be a chance occurrence as l&4 had fewer

stems than the other treatments both at age 11 and

through two recuttings. Based on the five numbered

stumps per plot, average sprout numbers per stump

changed from 9.0 to 8.1, 5.9, 4.4, and 4.4 as the length

of the regrowth period increased from 1 to 5 years.

Through 5 years, 20 percent of the numbered stumps

died.

Before harvest at age 11, the tallest tree was 29.5 feet

(honeylocust (Gleditsia friacanthos L.)), and the largest

d.o.f. was 5.4 inches (sugarberry). After 5 years of regrowth, an ash was the tallest tree at 19.8 feet and also

had the largest d.o.f. of 3.3 inches (table 2). Fifty percent

of the yearly height growth was attained before the end

of May and more than 90 percent before the end of July.

An analysis of variance of annual height growth of the

tallest trees (using the 27 measurements with 1 year’s

regrowth, 21 with 2 years, 15 with 3 years, 9 with 4 years,

and 3 with 5 years) showed a significant (0.05 level)

linear trend of reduced growth with age. The quadratic

and cubic trends were also significant. Mean height

growth for years 1 to 5 following cutting was 5.8,3.5,2.5,

2.9, and 2.1 feet, respectively.

Basal area, based on d.o.f., averaged 108 ft* per acre

for all 15 plots before the stand was cut at age 11. Total

regrowth basal area for 5 years averaged 103 f-t2 per

acre.

Because of plot variation, covariance analysis was

used in analyzing both total recut Z(d.o.f.)**h and recut

Z(d.o.f.)**h mean annual increments (m.a.i.‘s) of 1 to 5

years, with the covariate being before cut Z(d.o.f.)**h. In

neither case did the regression slope differ from zero,

indicating original cut stem volume was not closely related to future stem volume production per unit area.

Correlation coefficients were only 0.136 and 0.161,

respectively.

Total recut dry weight yields per acre for treatments

4&l and 5 were about 44 percent greater numerically

Roger M. Krinard is mensurationist and Robert L. Johnson is principal silviculturist at the Southern Hardwoods Laboratory, maintained at Stoneville,

MS, by the Southern Forest Experiment Station, Forest Service-USDA, in cooperation with the Mississippi Agricultural and Forestry Experiment

Station and the Southern Hardwood Forest Research Group.

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Table 2.-Average tallest tree and largest diameter at 1 foot above ground at age 11 and at recutting(s)

with standard error, where SE = SD/fi

Height Diameter at 1 -foot

Treatment

11 years First Second

recutting recutting 11 years First Second

recutting recutting

-----_----__--__ feet---------------- ------------ inches -____._______

1, 4 23.7 f 1.7 6.5 + 1.0 16.1 2 0.5 3.9 * 0.7 0.8 f 0.1 1.820.2

2, 3 21.7 k 3.2 9.8 * 1 .O 12.9 _’ 1.0 3.2 f 0.8 1.3 f 0.1 1.5 k 0.1

3, 2 24.8 k 3.2 12.9 2 0.4 10.7 r 0.9 4.3 f 0.9 1.7 k 0.2 1.2 f 0.1

4, 1 24.2 f 2.8 17.9 _’ 0.3 7.6 f 0.2 3.3 f 0.4 2.4 I!T 0.2 0.8 _’ 0.0

5 19.8 * 0.3 19.320.3 . . . . . . . . 2.9 k 0.4 2.7 k 0.3 . . . . . . .

22.8 f 1.1 3.5 ” 0.3

Table 3.-Dry weight per acre mean annual increment by treatment at age 17 and at recutting(s) with

standard error, where SE = SD/e

Treatment 11 years First recutting Second recutting Total recutting

-------------------------poundsperacreperyear-----------------------.-

1, 4

2, 3

3, 2

4, 1

5

2,627 -’ 344 1,261 2 219al 3,167* 313 2,802 f 231a

3,622 f 796 3,822 f 902b 4,917 f 1,112 4,479 f 896ab

3,873 f 979 4,816 -c 1,257b 4,028 f 897 4,501 rt 1,093ab

3,224 2 519 7,006 + - 374~ 4,425 k 415 6,490 - e 378~

2,851 j: 140 6,427 _’ 218bc . . . . . . . . . . . 6,427 k 218bc

3,240 f 269

‘Means appearing with same letter not significantly different within each column at 0.05 level by the

Friedman test; if no letters, overall test was not significant.

than for treatments 2&3 and 3&2; the latter two treatments had total recut dry weight yields 60 percent

greater numerically than treatment l&4. However, only

treatments 4&l and 5 differed from treatment i&4 at the

0.05 level.

Table 4.-Total dry weight per acre prediction equations with one and

two independent variables

Dry weight m.a.i.‘s based on the first l- to C&year regrowth period differed significantly, while m.a.i.‘s based

on the second regrowth period of 1 to 4 years did not

differ (table 3). Dry weight m.a.i.‘s of 4 years’ and

5 years’ regrowth were greater than 11 -year m.a.i.‘s for

the same plots. Other regrowth m.a.i.‘s did not differ from

corresponding 11 -year m.a.i.‘s.

Dry weight (Ibs)/acre = 0.550245(2)“.872025

in log units, r2 = 0.,98, percent standard error = 9.3%

in actual units, rs = 0.95, Sy.x = 3364, (S,.,~)lOO = 15.6%

Dry weight (Ibs)/acre = 1 .572968(2)“.7ssoss 1 0-1585s3(1a)

in log units, R2 = 0.99, percent standard error = 8.3%

in actual units, R2 = 0.97, S,., = 2771, (S,.,/~)lOO = 12.9%

Z = Z(d.o.f.)z’h/acre; percent standard error = (lOa - 1)1’2100.

The volume/weight of sprouts from the five largest

stumps per plot proportional to total plot production was

variable. Where all five numbered stumps per plot survived, their percentage contribution to total C(d.o.f.)2*h

averaged 47 percent and ranged from 16 to 66 percent.

CONCLUSIONS

Dry weight per acre prediction equations were developed for aboveground biomass using all 42 complete

plot measurements (15 at age 11, 6 each for ages 1

through 4, and 3 for age 5) (table 4).

This study was conducted in a young natural stand

supplemented with acorn seeding that contained a mixture of species commonly found on slackwater sites in

river bottoms of the South. For similar conditions, the

following conclusions might be made:

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(1) After clearcutting, the stand will regenerate to the

same species via stump sprouts. Due to species differences in sprouting ability, some species wilt be better

represented in the new stand than they were in the old.

(2) Of the common commercial species, green ash is

the most consistent stump sprouter, and its sprouts are

the best early growers.

(3) Sprouts of all species follow the same pattern of

development: height growth will be most rapid the first

year after cutting and then tends to decline to a 2- to

3-foot-a-year rate for ages 3 to 5. Tallest sprouts may

grow to one-fourth the height of cut 1 l-year-old trees in

1 year and to two-thirds of that height in 5 years. Sprout

growth each year is essentially complete by the end of

July.

(4) Sowing acorns is a feasible method of establishing an oak component on slackwater sites following

clearing, as nearly all the Nuttall oak trees in these study

plots developed from handseeded acorns.

(5) Natural stand mean annual increment on bottomland clay soils is apparently maximized around 4 or

5 years or possibly a year or two later, but before

11 years.

(6) Potential yields from short rotation harvests of

aboveground biomass may exceed 3 dry tons/acre/year,

at least through one 4- or 5-year rotation. Whether this

yield level can be sustained over several rotations is

unknown. The yields do not differ much from those of far

more intensively managed and expensive close-spaced

sycamore plantations on better riverfront sites with

medium-textured soils that produced 3-l/2 tons/acre/

year over a first 4-year rotation and 3-l/4 tons over a

second (Kennedy 1980).

LITERATURE CITED

Kennedy, Harvey E., Jr. Coppice sycamore yields

through 9 years. Research Note SO-254. New

Orleans, LA: U.S. Department of Agriculture, Forest

Service, Southern Forest Experiment Station; 1980.

4 PKrinard, Ft. M.; Johnson, R. L. Description and yields of

an 11 -year-old hardwood stand on Sharkey clay soil.

Research Note SO-265. New Orleans, LA: U.S.

Department of Agriculture, Forest Service, Southern

Forest Experiment Station; 1981. 2 p.

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