United States

Department of

Agriculture

“,llF i’*(

i-i-l u s

w Southern Forest

Forest Service Research Note

Experiment Station SO-348

June 1988

Stand Parameters of a 27-Year-Old Water Oak Plantation on

Old Field Loessial Soils

Roger M. Krinard and Robert L. Johnson

SUMMARY

At age 27, water oak (Quercus nigra L.) plantings on

Macon Ridge old field loessial soil near Winnsboro, Louisiana, had per-acre stand values as follows: number of

trees, 356; average d.b.h., 6.6 inches; basal area, 86 ft*;

total volume from the stump to the tip (of trees with d.b.h.

25.0 in), 2,Oi 7 ft3; average height of the 50 tallest trees,

61 ft.

had the neighboring fields that still remain in crops. The

water oak plantings consisted of a 14 l/2-acre tract on a

larger field and a 6 l/2-acre tract on a smaller field.

Additional keywords: Pinus elliottii, plantation costs,

Quercus nigra.

Records show that 20,000 oaks were planted on the

21 acres, approximately 950 trees per acre-about 46

square feet per tree. Original spacing between rows appears to have been mainly about 9 to 10 feet, although

spacing varied to as close as 6 feet. In some instances

parts of rows were completely missing, but whether from

mortality or not being planted is unknown. Within-row

spacing was variable. After planting, no cultivation or

weed control was done.

INTRODUCTION

Growth and yield data for oak plantations 20 years of

age and older in the Midsouth are very limited. Although

plantations represent only a fraction of the hardwood

resource, planting is one way to establish a desired

species on a given site. Information on development of

plantations is desirable so that some idea of returns can

be obtained on the high cost of establishment and to make

comparisons with natural regeneration on similar sites. In

the case reported here, 27-year-old water oak (Quercus

nigra L.) plantations on two fields were made available for

measurements by the landowner, who had originally

planted the trees on land that produced below average

crops (fig. 1).

METHODS

STUDY AREA

In the fall of 1986, thirty-six O.l-acre measurement

plots were systematically established in the water oak

plantings on a 150-foot by 15-row grid, with 27 of the plots

in the larger field. On the plots all trees were measured for

d‘b.h. and assigned to a crown class. Five dominantcodominant trees were measured for total height, as were

two to three intermediate or suppressed trees. Near each

plot center, soil samples were taken from the surface O-to

1 O-inch level and from the lo- to 20-inch level. Additional

samples at the 20-to 30-inch level and 30-to 40-inch level

were planned, but afragipan at about 20 inches prevented

deeper sampling on all but four plots. For comparison, soil

samples were taken from two locations in an adjacent

field.

The plantations were established the first 2 weeks in Twenty water oak trees were felled and diameters of

February 1960 on old fields of loessial soil on Macon the bole measured at 4-foot intervals to the tip, starting at

Ridge near Winnsboro, Louisiana. The fields had been -a 1 -foot stump, in order to develop a main stem outside

under cultivation for decades prior to planting trees, as bark volume equation. Four codominant trees were

Southern Forest Experiment Station/l-10210 U.S. Postal Services Bldg., 701 Loyola Avenue, New Orleans, La. 70113

Forest Service, U.S. Department of Agriculture.

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

1
Figure 1. - General view of a 27-year-old water oak plantation on old field loessial soil

measured for height to live crown and maximum crown

spread in cardinal directions, then felled and sectioned at

5foot intervals. Ring counts were made to determine

height development over time.

RESULTS AND DISCUSSION

Texture of all soil samples was either silt loam or silty

clay loam. The plantation soil pH of most samples was

very strongly acid (4.5 to 5.0). An adjacent agricultural

field had surface pH’s of 5.3 and 5.9 and a hardpan at 20

inches, as did most samples taken from the woods.

Because of the pan conditions encountered in soil

sampling the soils could probably be best described as

a Calhoun-Calloway complex and Calhoun-Loring complex. All three soils developed from loess with Calloway

and Loring having fragipans.

Broadfoot (1976) listed Calloway as having an estimated site index range for water oak of 65 to 85 feet at

50 years. In an earlier publication, Broadfoot and

McKnight (1961) did not recommend favoring water oak

as a future stand component on either Loring or

Calhoun, and Broadfoot (1963) estimated a water oak

site index for medium textured soils with a pan within 30

inches of the surface as 75 to 84 feet. From extrapolated

curves (Broadfoot 1963) individual plot site indices varied from 68 to 100 feet and averaged 86 feet.

Because of height variations within the oak plantation, a total height over d.b.h. curve of the form In(height)

= b, + b, (l/d.b.h.) was calculated for each plot using the

seven to eight trees measured for height on the plot.

Total stem volume outside bark (V) from a 1 -foot stump

to the tip was determined from:

V = 0.0007t8Dl.677262 Hl.450060

n = 20, fit index = 0.92, S, = 1.12, CV = 14.5%.

Plot volumes were determined using 1 -inch diameter

classes and height over diameter curves, where D = d.b.h.

class midpoint (e.g., 10.45 inches) and H = total height in

feet as calculated from D.

The per-acre stand parameters of the 27-year-old

water oak plantation based on the 36 plots for total trees

and dominant/codominant trees are shown in table 1. The

dominant/codominant component comprised 74 percent

of the trees, 87 percent of the basal area, and 88 percent

of the volume. The average respective diameters, in

inches, of the dominant, codominant, intermediate, and

suppressed trees were 9.0,6.7,5.1, and 4.0; average respective basal areas, in ft*/acre, were 14.7,60.4,6.7, and

4.3. Height and diameter distributions are shown in figures 2 and 3.

Live crown ratios averaged 48 percent for the four

codominant trees sampled, which averaged 7.4 inches in

d.b.h. and 59.2 feet tall. Average respective heights at 5,

10,15,20, and 25 years, from ring counts, were 7,20,34,

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

Mississippi, 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 1 .-Per-acre stand parameters for total trees and dominantlcodominant trees of a 27-year-o/d

water oak plantation, based on 36 plots

Stand parameter Total trees Dominantkodominant trees __--.

_____..__________._____ Mean k standard error (range) ________..._________.

Number of trees 356 + 16 (130-530) 264 f 1 2 (90-400)

Avg. d.b.h. (in) 6.6 It 0.2 (4.9-9.2) 7.2 f 0.2 (5.3-10.1)

Basal area (ft2) 86.1 2 2.8 (50.6-125.8) 75.0 + 2.4 (41 .l-109.7)

Volume (ft3) 2166 + 102 (11353831) 1908 zk 8 9 (1044-3390)

Volume (ft3, d.b.h. 2 5.0 in) 2017 + 106 (1080-3756) 1862 f 9 3 (1044-3390)

10 tallest trees (ft) 64.4 k 1 .O (49-77)

Avg. 50 tallest trees (ft) 60.6 + 0.9 (47.4-71.8)

___-__

46, and 56 feet, with corresponding mean annual height

increments of 1.4,2.0,2.3,2.3, and 2.2 feet per year and

5-year periodic annual increments of 1.4, 2.6, 2.8, 2.4,

and 2.1 feet per year. Thus maximum height growth

occurred in the 11 th- through 15th-year period. Eighty

percent of the 27-year diameter growth at a height of 5

feet took place during the first 15 years, after which a fairly

uniform slow down in diameter growth occurred.

The 28foot difference in the tallest tree per plot or 24-

foot difference in the average of the five tallest trees per

plot could not be related to various soil nutrients (N, P, K,

Ca and Mg), soil texture, pH, or organic matter. Microsite

4 5 5 0 5 5 6 0 6 5 7 0 7 5

HEIGHT (FEET)

moisture relationships and fragipan development were

probably the main influencing factors, together with possible genetic differences in planting stock. Differences

between the woodland soil and soil in the adjacent agricultural field were: in the surface 0 to 10 inches, greater

amounts of Cain the field (1,064 vs. 392 ppm, p <O.OlO)

and a higher percentage of organic matter in the woods

(1.19 vs. 0.48 percent, p = 0.013); in the lo- to 20-inch

depth there was more K in the field (136 vs. 101 ppm, p

= 0.041).

The development of the water oak can be compared

with slash pine (Pinus elliottii Engelm.), which was

D. B.H. (INCHES)

Figure 2. - Height distribution of 180 dominanVcodominant trees. Figure 3. - Diameter distribufion per acre for frees 2 1.0 inches d.b.h.

3
Figure 4. - Shallow root development of windthrown water oak tree that had been growing in the 27-

year-old plantation.

planted at the same time on fields adjacent to the oak

plantings. Based on five random 0.1 -acre plots in the pine

plantings, the 27-year-old pine values exceeded the oak

values with 16 percent more trees, 30 percent larger

average d.b.h., 20 percent taller heights, 105 percent

more basal area, and 192 percent more cubic volume in

trees 25.0 inches d.b.h.

This planting has provided information on old field

water oak plantation development on loessial soil with a

fragipan, a less than ideal site that limits root growth and

is subject to growing season drought. These pure oak

stands have continued to develop through 27 years with

crown class differentiation and 20 to 25 feet of limb-free

boles among larger trees. Site differences may be partly

responsible for the different growth patterns between the

oaks, though. A slowing of both diameter and height

growth may be partly due to stagnation of the pure oak

stand but is mostly due to the fragipan soil. An intermediate thinning for the purpose of increasing growth of crop

trees and for utilizing low vigor and poor quality trees is

probably desirable, but because of size, cut trees would

be more for firewood than pulpwood. Because rooting of

the oak trees is shallow due to a pan (see fig. 4), any

thinning to open the stand should probably be light.

Per-acre cost of planting, including labor, supervision,

seedlings, and other expenses was $11.74. Price of

seedlings in 1960 was $4.25 per thousand.

LITERATURE CITED

Broadfoot, W. M. 1963. Guide for evaluating water oak

sites. Res. Pap. SO-l. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest

Experiment Station. 8 p.

Broadfoot, Walter M. 1976. Hardwood suitability for and

properties of important Midsouth soils. Res. Pap.

SO-127. New Orleans, LA: U.S. Department of

Agriculture, Forest Service, Southern Forest Experiment Station. 84 p.

Broadfoot, W. M.; McKnight, J. S. 1961. Soil suitability for

forest trees in deep loess areas. Information Sheet

722. State College, MS: Mississippi Agricultural Experiment Station, Mississippi State University. 2 p.