United States

Department of

Argriculture

0

mIIRIrnL Forest Service Research Note

so-371

Southern Forest

Experiment Station January 1993

Effects of Crown Position and Initial Spacing on Foliar Nutrient

Composition of Seven Bottomland Hardwoods

Harvey E. Kennedy, Jr.

SUMMARY

Seven plantation-grown bottomland hardwoods,

sweetgum (Liquidambar stryaciflua L.), green ash

(Fraxinus pennsylvanica Marsh.), American sycamore

(Platanus occidentalis L.), water oak (Quercus nigra L.),

Nuttall oak (Q. nuttallii Palmer), cherrybark oak (Q. falcafa var. pagodifolia Ell.), and swamp chestnut oak (Q.

michauxii Nutt.), were sampled after the seventh growing season to determine foliar nutrient concentrations.

Foliage samples were collected from the upper, middle,

and lower crown positions and from the entire crown.

Determinations were made for levels of nitrogen, phosphorus, potassium, calcium, and magnesium. Spacing

had no effect on nutrient concentrations. Nutrient levels

differed by crown position for some nutrients in most

species. Most of the differences were in the nitrogen,

calcium, and magnesium levels.

Keywords: Calcium, Fraxinus pennsylvanica, nitrogen,

plantation, Quercus nigra.

INTRODUCTION

Extensive clearing of bottomland hardwood forests for

agricultural crop production in the Southern and

Southeastern United States occurred during the late

1960’s and early 1970’s. Recently, however, several incentives to reforest some of these lands have been offered. Perhaps the best known of these is the Conservation Reserve Program (CRP) established under the 1985

Farm Bill (P.L. lOO-233), which provides cost sharing

and annual rental payments for reforestation and a number of other soil conservation practices. In February

1989, flood-prone croplands were brought under the

1985 Farm Bill (CP-14), which made millions of acres of

croplands-those suitable for hardwood reforestationeligible for benefits.

Inexpensive reforestation methods are required to

take full advantage of opportunities under CRP. Work at

the USDA Forest Service’s Southern Hardwoods

Laboratory at Stoneville, MS, has shown that directseeding of oaks (Quercus spp.) and planting of 1-O

bare-root nursery stock of a number of bottomland

hardwood species can work well when reforesting

agricultural fields (Baker and Blackman 1978, Francis

1983, Johnson 1983, Johnson and Krinard 1987, Kennedy 1985, Kennedy and others 1986). A number of

State and Federal natural resource management agencies, private landowners, and hunting clubs have begun

to apply these methods on a relatively large scale. For

example, the Louisiana Department of Wildlife and

Fisheries has planted and direct-seeded over 4,000

acres of bottomland oaks on the Ouachita Wildlife

Management Area since 1985. And the Mississippi

Department of Wildlife, Fisheries and Parks is well into a

1 O-year project to reforest nearly 1,000 acres on the Malmaison Wildlife Management Area by direct-seeding.

These are only two examples of many that could be

cited.

Most southern hardwood reforestation projects are

being undertaken on land that has been in agronomic

production (old fields) for a number of years. Information

on the effects of agronomic practices on the nutrient

properties of soils and the resultant influence on tree

growth are unavailable. Past research at the Southern

Southern Forest Experiment StationIT-102lO U.S. Postal Services Bldg., 701 Loyola Avenue, New Orleans, La. 70113

Forest Service, U.S. Department of Agriculture.

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

1
Hardwoods Laboratory has shown that trees planted on

old-field sites can often respond favorably to fertilizer

amendments (Francis 1985). If tree growth on old-field

sites is not satisfactory, landowners may want to fertilize

to possibly accelerate growth rates. One way to get an

indication of whether trees will respond to fertilization is

to determine foliar nutrient levels and compare these

levels with levels in trees growing at acceptable rates.

Growth rates on the study sites had been good for 10

years (Kennedy and others 1987, Schlaegel and Kennedy 1985). Therefore, nutrient levels reported in this

paper may give an indication of productivity on similar

sites.

Researchers have examined various aspects of sampling at different times during the growing season and

have chemically analyzed different components of the

leaf (Haines and others 1979, Shelton and others 1981,

Smalley 1976). Most studies, however, have included

only one species and one spacing. In this paper, comparisons of nutrient levels are made by crown position

for seven hardwood species planted at five spacings in a

minor stream bottom.

METHODS

This study, during its seventh growing season, was

superimposed on an earlier study, “Effects of Spacing on

Species Yields in Minor Bottoms.“’

The principal soil series on the study area is Arkabutla, a member of the fine-silty, mixed, acid, thermic family

of Aeric Fluvaquents. These are somewhat poorly

drained soils that usually develop on slopes of 0 to 2 percent in flood plains within the silty uplands. They are

good hardwood sites with a site index range at 50 years

of 95 to 115 ft for cherrybark oak (Quercus falcata var.

pagodifolia Eli.) and 90 to 110 ft for sweetgum (Liquidambarsfyraciflua L.). Broadfoot (1976) classifies the

site as favorable for plantation management and suitable

for planting all of the species in these two studies.

Species investigated were American sycamore

(Platanus occidentalis L.), sweetgum, green ash

(Fraxinus pennsylvanica Marsh), swamp chestnut oak

(Quercus michauxiiNutt.), water oak (Q. nigra L.), Nuttall

oak (Q. nuttallii Palmer), and cherrybark oak. The trees

were planted at spacings of 2 by 8,3 by 8,4 by 8,8 by 8,

and 12 by 12ft.

‘Schlaegel, Bryce E.; Kennedy, Harvey E., Jr. 1976. Study plan on file

with Southern Hardwoods Laboratory, U.S. Department of Agriculture,

Forest Service, Southern Forest Experiment Station, Stoneville, MS

38776.

Each plot consisted of 169 trees planted in a rectangular grid of 13 by 13 rows. The interior 5 by 5 rows were

designated as a permanent remeasurement area in the

earlier study, with the four rows outside this area (on

each side) being the border rows. The interior two rows

of the four border rows were designated for destructive

sampling. Beginning in the fall of 1977 in the earlier

study, three of the four plots for each spacing and

species were selected for destructive sampling. Trees

from these same three plots had been sampled in the fall

of each year. Because of the vast amount of work involved in the earlier study, it was impractical to sample

all plots; therefore, the plots used for sampling in that

study were systematically chosen from blocks by

species and spacing based on survival and growth (Kennedy and others 1986).

Foliar sampling was done during the first and second

week in August following the recommendations of Smalley (1976). In this study, two trees representative of the

average tree of the whole plot were selected for sampling. The trees were cut to facilitate sampling and

measuring. The live crown was then divided into thirds,

representing the lower, middle, and upper crown. Two

representative branches, opposite each other, were

selected from the center of the lower, middle, and upper

crown, and foliar samples were collected from these

branches. Samples were kept separate by plot and

crown position, but samples from the two trees per plot

were composited for each crown position for nutrient

determinations. After samples for each crown position

were obtained, a sample from the whole crown was

taken so that nutrient levels for the whole tree crown for

each plot could be determined. A total of 210 trees was

sampled on 105 plots (3 blocks by 5 spacings by 7

species = 105). There were 4 foliar samples per plot for

a total of 420 samples.

Foliar samples were dried at 70 “C and ground

enough to pass through a 2-mm sieve in preparation for

chemical analyses. Concentrations of nitrogen (N),

phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were determined for each sample. Nitrogen

level was determined by using standard Kjeldahl procedures; P level by calorimetry with molybdenum blue

color development; and K, Ca, and Mg levels by atomic

absorption spectrophotometry after samples had been

dry-ashed and taken up in dilute HCI.

STATISTICAL ANALYSES

As stated earlier, the plots from which trees were

sampled were selected from the blocks in the earlier

study (Kennedy and others 1986) by species and spacHarvey E. Kennedy, Jr. is principal silviculturist at the Southern Hardwoods Laboratory, U.S. Department of Agriculture, Forest Service, Southern

Forest Experiment Station, Stoneville, MS 38776. In cooperation with: Mississippi Agricultural and Forestry Experiment Station and the Southern

Hardwood Forest Research Group.

2
ing. Because of the manner in which plots were selected,

blocks were not considered a factor in analyzing the

data. A split-plot, completely randomized design was

used with spacing being the whole plot and crown position the subplot. There were three replications of each

treatment-spacing by crown position. A separate

analysis was performed for each species/nutrient combination. Analyses of variance (ANOVA’s) of foliar

nutrient concentrations by spacing and crown position

for each of the seven species (a total of 35 ANOVA’s)

were made at the 0.05 level. The ANOVA format is given

in table 1. Duncans’ new multiple-range test was used to

determine differences among means.

RESULTS AND DISCUSSION

Statistical analyses revealed that spacing had no significant effect on nutrient concentrations for any of the

species or nutrients tested. The replication by crown

position interaction was statistically significant for K in

cherrybark oak, for K and Ca in sweetgum, and for N in

sycamore. Spacing can be discounted as having an effect on the interactions because it had no effect on

nutrient concentrations. Probable explanations for the

significant interactions between replications and crown

position are differences in site quality due to drainage,

soil moisture, or other site factors and/or minor differences in plant nutrient concentrations resulting from differences in sampling procedures. None of the other

interactions were statistically significant. Nutrient concentrations for the upper, middle, lower, and entire

crown positions are given in table 2. Nutrient concentrations differed by crown position for some nutrients in

most species. These differences are discussed

separately by nutrient category in the following paragraphs.

Nitrogen

Nitrogen concentrations differed significantly by

crown position for all species except sycamore (table 2).

The upper crown was highest in N concentrations for

water oak, Nuttall oak, sweetgum, and green ash; the

Table 1 .- The format used for individualANOVA3

Source d.f.*

Replications (R) 2

Spacing (S) 4

Error A 8

Crown Position (CP) 3

RXCP 6

SXCP 1 2

Error S 2 4

Total 5 9

middle crown was highest in N for cherrybark oak and

swamp chestnut oak. There was a significant replication

by crown position interaction for N in sycamore. The

lowest concentrations were found in the lower crown and

entire crown. Higher N concentrations in the upper

crown could have been due to the mobility of N and its

translocation to areas where new foliage and tissue were

being formed near the meristem; lower concentrations in

the lower crown indicate slower growth rates (Shelton

and others 1981).

Table 2.- Means for tested nutrients by species and crown position

averaged over all spacings*

Crown

position N P K Ca Mg

Water oak

Lower

Middle

Upper

Entire

Nuttall oak

Lower

Middle

Upper

Entire

Cherrybark oak

Lower

Middle

Upper

Entire

_____________________________ percent ____________________________

1.4391, 0.083b 0.593 0.828a 0.167a

1.515a .087a .579 .709b .147b

1.539a .085a .575 ,620~ .135c

1.440b .087a .609 ,721 b .145b

1.488bc 0.091

1.538ab ,092

1.563a .093

1.451c .094

0.663b 0.733a 0.134a

.731a .604bc .119bc

.734a .576c .113c

.726a .634b .123b

1.601b 0.091b 0.670ab 1.177a 0.193a

1.688a .095a .642b .945b .157b

1.651 ab .091 ab .719a .747c .135c

1.538~ .093ab .700ab .911b .154b

Swamp chestnut oak

Lower 1.680ab 0.109

Middle 1.720a .112

Upper 1.641 bc .107

Entire 1.591c .llO

Sweetgum

Lower

Middle

Upper

Entire

1.12oc 0.110

1.185b .112

1.279a .112

1.161bc ,111

Green ash

Lower

Middle

Upper

Entire

1.469c 0.143

1.537b ,149

1.621a ,140

1.455c ,141

Sycamore

Lower

Middle

Utwer

Entire

1.322 0.109b 0.65613 0.990a 0.238a

1.347 .lllab .654b .831 b .217b

1.416 .116a .670ab .729c ,203~

1.323 .114ab .715a .840b .219b

0.571 b 1.477a 0.130a

.599ab 1.232b .114bc

.641a .998c .106c

.627a 1.265b .122ab

0.521 b 1.519a 0.348a

.571ab 1.187b .265b

.556ab .705c .199c

.636a .933b .242b

0.829 0.950a 0.178

.851 .791 b .175

.841 .686c .169

.873 .757b .173

*Values in a column followed by the same letter are not significantly

different at the 0.05 level. Where no letters appear, overall tests were

l d.f.=degrees of freedom not significant.

3
Phosphorus

Crown position had no significant effect on P concentrations in Nuttall oak, swamp chestnut oak, sweetgum, and green ash but did in water oak, cherrybark oak,

and sycamore (table 2). Crown positions with the highest

P concentrations varied by species. The numerical

nutrient concentrations in water oak, cherrybark oak,

and sycamore generally differed only at the third decimal

place; these differences have little practical importance.

Potassium

Potassium levels differed significantly by crown position for all species tested except water oak and green

ash (table 2). Levels varied by crown position among

species but generally were highest in the upper crown

and entire crown and lowest in the lower crown. As with

P, the numerical differences in nutrient concentrations

were very small.

Calcium

Concentration levels differed significantly by crown

position for all seven species tested. Levels were significantly highest in the lower crown and lowest in the

upper crown in all species (table 2). Concentrations in

the middle crown and entire crown were intermediate in

value and did not differ from each other. The higher concentrations in the lower crown were probably due to the

relative immobility of Ca, which is not translocated as

rapidly to the middle and upper crowns as are the more

mobile nutrients such as N (Baker and Blackman 1978,

Shelton and others 1981).

Magnesium

Magnesium concentrations were affected by crown

position in all species except green ash (table 2). As with

Ca, the highest concentrations were in the lower crown

and the lowest concentrations in the upper crown. Concentrations in the middle crown and entire crown were

intermediate in value. Again, as with Ca, the low concentrations in the upper crown can probably be attributed to the relative immobility of Mg and its inability to

readily translocate to the upper crown.

Nutrient Concentrations

Concentrations of nutrients in tree tissue are accepted as good indicators of growth and soil fertility on a

site and indicate whether trees on a given site may or

may not respond to fertilizer amendments (Haines and

others 1979, Shelton and others 1981, White and Carter

1970). Using these assumptions, the upper or middle

crown would be the most appropriate area for sampling

the highest N concentrations in most of the species

tested in this study. The upper crown or entire crown

would be the most appropriate area for sampling K. The

highest concentrations of Ca and Mg were found in the

lower crown. From a practical standpoint, however, it appears that a representative sample from the entire crown

would be adequate for sampling all nutrients. Ranges in

nutrient concentrations among crown positions are

small. Also, concentrations in samples for the entire

crown for most nutrients and species are within the

range of concentrations in samples for the different

crown positions (table 2). If sampling is done to determine the nutrient concentrations of several elements in a

large number of species, keeping tissue samples

separate by crown position during sampling, tissue

preparation, and laboratory analyses would be a laborious task. One sample from the entire crown could be

used to eliminate the task of collecting and keeping up

with separate samples by crown position for each

species.

The average size of trees for each spacing after

seven growing seasons for the seven species are given

in table 3. Good growth rates for the four oaks continued

Table 3.- Average d.b.h. and total height (Ht.) at age 7 for the seven plantation-grown species by

spacing

Spacing

Species*

2 b y 8 3 b y 8 4 b y 8 8 b y 8 12by12

D.b.h. Ht. D.b.h. Ht. D.b.h. Ht. D.b.h. Ht. D.b.h. Ht.

In ft In Ft In Ft In Ft In Ft

S G 2.03 23.2 2.21 23.4 2.59 25.5 3.18 27.1 3.79 28.0

G A 1.53 18.9 1.43 16.2 1.89 20.8 2.36 22.1 3.22 25.9

SYC 1.42 18.4 1.63 19.5 1.83 20.8 2.83 28.5 3.33 27.3

WA0 1.50 16.7 1.49 16.5 1.83 18.6 1.90 17.7 2.36 18.6

NO 1.40 14.3 1.44 13.5 1.77 15.3 1.68 12.9 2.10 15.3

CBO 1.20 12.8 1.22 13.0 1.63 15.6 1.67 13.9 1.88 13.9

SC0 .93 9.4 .59 7.6 1.07 10.2 1.03 9.5 .97 8.5

*SG=sweetgum; GA=green ash; SYC=sycamore; WAO=water oak; NO=Nuttall oak; CBO=cherrybark oak; and SCO=swamp chestnut oak.
through age 10 in the earlier study (Kennedy and others

1987) and were predicted to be good for the three nonoak species (Schlaegel and Kennedy 1985). Concentrations of tissue nutrients for most species in this study,

particularly N, were lower than the concentrations suggested by others for good growth in various bottomland

hardwoods (Norris and others 1980, White and Carter

1970). These results indicate that more research is

needed to determine minimum nutrient requirements for

good growth in most hardwoods.

Past research at the Southern Hardwoods Laboratory

has shown that trees planted on old-field sites can often

respond favorably to fertilizer amendments (Francis

1985). Good growth was achieved for 10 years in the

earlier study with the same species tested at the nutrient

levels measured in this study. Landowners may want to

use these nutrient levels and growth responses as an indichtion of site productivity in this area, particularly with

plantings in the CRP where many such reforestation efforts are being done on old-field sites. If the growth and

nutrient levels of trees are not satisfactory on a site,

small fertilizer tests could be established to determine

whether fertilization over the entire plantation might accelerate growth to a more satisfactory level.

SUMMARY AND CONCLUSIONS

Statistical analyses revealed that spacing had no effect on nutrient concentrations for any of the species

tested. Crown position did significantly affect some

nutrient concentrations by species; concentrations of N,

Ca, and Mg were affected the most. Nitrogen concentrations were generally highest in the upper crown, and Ca

and Mg were highest in the lower crown.

LITERATURE CITED

Baker, James B.; Blackman, B.G. 1978. Summer fallowing-a simple technique for improving old-field sites

for cottonwood. Res. Pap. SO-1 42. New Orleans, LA:

U.S. Department of Agriculture, Forest Service,

Southern Forest Experiment Station. 5 p.

Broadfoot, Walter M. 1976. Hardwood suitability for and

properties of important Midsouth soils. Res. Pap. SO127. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment

Station. 84 p.

Francis, John K. 1983. Cherrybark and Shumard oaks

successfully planted on eroded ridges. Tree Planters’

Notes. 34(2): 2830.

Francis, John K. 1985. Bottomland hardwood fertilization-the Stoneville experience. In: Shoulders,

Eugene, ed. Proceedings of the 3d biennial Southern

silvicultural research conference; 1984 November 7-

8; Atlanta, GA. Gen. Tech. Rep. SO-54. New Orleans,

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

Southern Forest Experiment Station: 346-350.

Haines, Sharon G.; Haines, L. Wayne; White, Gordon.

1979. Nutrient composition of sycamore blades,

petioles, and whole leaves. Forest Science. 25(l):

154-160.

Johnson, R.L. 1983. Nuttall oak direct seedings still successful after 11 years. Res. Note SO-301. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 3 p.

Johnson, Robert L.; Krinard, Roger M. 1987. Direct

seeding of southern oaks-a progress report. In: 15th

annual hardwood symposium of the Hardwood Research Council: applying the latest research to

hardwood problems; Proceedings; 1987 May 1 O-l 2;

Memphis, TN. Broomall, PA: U.S. Department of

Agriculture, Forest Service, Northeastern Area State

and Private Forestry: 1 O-l 6.

Kennedy, Harvey E., Jr. 1985. Cultural treatments influence hardwood growth and foliar nutrient concentration on a minor stream bottom site. Res. Pap.

SO-215. New Orleans, LA: U.S. Department of

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

Kennedy, Harvey E., Jr.; Krinard, Roger M.; Schlaegel,

Bryce E. 1987. Growth and development of four oaks

through age 10 planted at five spacings in a minor

stream bottom. In: Daniels, Robert A.; Watson, W.F.;

Savelle, I. Winston, eds. Proceedings of the 1987

southern forest biomass workshop: 9th annual meeting of the Southern Forest Biomass Working Group;

1987 June 8-l 1; Biloxi, MS. Mississippi State, MS:

Mississippi State University: 81-91.

Kennedy, Harvey E., Jr.; Schlaegel, Bryce E.; Krinard,

Roger M. 1986. Nutrient distribution and tree development through age 8 of four oaks planted at five spacings in a minor stream bottom. In: Brooks, Robert T.,

ed. Proceedings of the 1986 Southern forest biomass

workshop: 8th annual meeting of the Southern Forest

Biomass Working Group; 1986 June 16-19; Knoxville, TN. Norris, TN: Tennessee Valley Authority: 65-

70.

Norris, James Lawrence; White, Gordon; Sims, Donald.

1980. The relationship of soil, foliar, and topographical conditions to American sycamore (Platanus occidental& L.) growth in a plantation. Tech. Rep. 63.

5
Raleigh, NC: School of Forest Resources, North

Carolina State Forest Fertilization Cooperative. 35 p.

Schlaegel, Bryce E.; Kennedy, Harvey E., Jr. 1985. Do

different young plantation-grown species require different biomass models? In: Saucier, JR., ed.

Proceedings of the 1984 southern forest biomass

workshop: 6th annual meeting of the Southern Forest

Biomass Working Group; 1984 June 5-7; Athens,

GA. Asheville, NC: U.S. Department of Agriculture,

Forest Service, Southeastern Forest Experiment Station: 23-35.

Shelton, M.G.; Nelson, L.E.; Switzer, G.L.; Blackman,

B.G. 1981. The concentration of nutrients in tissues of

plantation-grown eastern cottonwood (Populus de/-

toides Bartr.). Tech. Bull. 106. Mississippi State, MS:

Mississippi Agricultural and Forestry Experiment Station, Mississippi State University. 10 p.

Smalley, G.W. 1976. Seasonal variation in the nutrient

composition of yellow-poplar leaves. In: Fralish,

James S.; Weaver, George T.; Schlesinger, Richard

C., eds. Proceedings of the central hardwood forest

conference; 1976 October 17-l 9; Carbondale, IL.

Carbondale, IL: Southern Illinois University: 377-385.

White, E.H.; Carter, M.C. 1970. Relationships between

foliage nutrient levels and growth of young natural

stands of Pop&s deltoicfes Bartr. In: Youngberg,

C.T.; Davey, C.B., eds. Tree growth and forest soils.

Proceedings of the 3d North American forest soils

conference; 1968 August; Raleigh, NC. Corvallis, OR:

Oregon State University Press: 283-294.