Annual Growth of Suppressed 

Chestnut Oak and Red Maple, 

A Basis for Hydrologic 

Inference 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 485-C 

Annual Growth of Suppressed 

Chestnut Oak and Red Maple, 

A Basis for Hydrologic 

Inference 

By RICHARD L. PHIPPS 

VEGETATION AND HYDROLOGIC PHENOMENA 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 485-C 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1967 
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary 

GEOLOGICAL SURVEY 

William T. Pecora, Director 

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402 -Price 30 cents (paper cover) 
CONTENTS 

<Jlossary __________________________________________ _ 

Abstract __________________________________________ _ 

Introduction ______________________________________ _ 

Acknowledgments __________________________________ _ 

The study area ____________________________________ _ 

The study trees ____________________________________ _ 

Description of trees ____________________________ _ 

Measurement methods _________________________ _ 

Page 

IV 

C1 

1 

2 

2 

3 

3 

5 

<Jrowth form ______________________________ -- _____ --

Annual increments in red maples RM-18 and 

RM-61--------------------------------------

Earlywood growth of chestnut oaks C0-58 and 

C0-31--------------------------------------

Discontinuous rings ________________________________ _ Summary _________________________________________ _ 

List of trees ___________________________ - - - - - - - - - - - - -

References cited ___________________________________ _ 

ILLUSTRATIONS 

Page 

C7 

8 

16 

19 

26 

27 

27 

Page 

FIGURE 1. Photograph of lower northeast-facing slope vegetation______ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ C2 

2. Photograph of middle southwest-facing slope vegetation ________________________________ -- ----------- 3 

3. Sketch showing part of cross-valley transect________________________________________________________ 4 

4. Sketch of tree stem illustrating hypothesized three-dimensional relationships between rings and annual 

increments___________________________________________________________________________________ 6 

5-8. <Jraph showing ring-width sequences of5. Red maple RM-18 plotted by year of ring formation ______________________________________ -- 8 

6. Red maple RM-61 plotted by year of ring formation_________________________________________ 9 

7. Red maple RM-18 plotted by ring number from center of cross section_________________________ 10 

8. Red maple RM-61 plotted by ring number from center of cross section_________________________ 11 

9. Diagram showing stem shape of red maples RM-18 and RM-61 at 10-year intervals____________________ 12 

1Q-13. Graph showing10. Height growth of the four sample trees_____________________________________________________ 12 

11. Ring-area growth of red maple RM-18----------------------------------------------------- 13 

12. Ring-area growth of red maple RM-61_---------------------------------------------------- 14 

13. Diagrams showing vertical distribution of annual ring-area increment__________________________ 15 

14-19. Graph showing14. Ten-year ring-area growth increments of red maples RM-18 and RM-61_______________________ 16 

15. Growth rates of a chestnut oak and a red maple, 1959_______________________________________ 17 

16. Annual ring-width sequences of chestnut oak C0-58_________________________________________ 18 

17. Annual ring-width sequences of chestnut oak C0-37_________________________________________ 19 

18. Frequency distribution of earlywood width measurements____________________________________ 20 

19. Ring-area growth sequences of earlywood and latewood, and generalized curve of total ring-area 

growth of chestnut oak C0-58_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 23 

20. Sketch of diagrammatic representation of discontinuity of outer 10 rings at 6-foot level of red maple RM -18_ _ 24 

21. Diagrams of discontinuous growth of individual rings of red maple RM-18 _________ .. ______ --- _--------- 25 

ill 
GLOSSARY 

Annual increment.-The three-dimensional sheath of xylem added to stems and secondary roots each year. 

The annual increment has the appearance of a ring (annual ring) when viewed in cross section. 

Auxins.-Growth regulators, such as hormones, affecting cell enlargement. 

Basipetal.-Proceeding from the top toward the base. 

Cambial activity.-The process by which cambial initials divide and form derivatives which differentiate into 

phloem cells outward from the cambium or xylem cells inward from the cambium. 

Cambium.-A tissue in many higher plants, including trees, in which cells divide and form new tissues. The 

cambium is located in stems and woody roots (not in stem tips and root tips) between the wood (xylem) 

and inner bark (phloem). 

Canopy.-The uppermost level of tree crowns in a forest. All tree crowns in the canopy level are exposed, at 

least in part, to direct sunlight. 

Conifer.-Any cone-bearing tree (most of which trees retain their leaves, or needles, throughout the year) such 

as pine and hemlock. 

Crown.-The part of a tree that includes leaf-bearing branches. There may or may not be a distinct branchfree trunk below the crown and a single main stem which may or may not be distinguishable in the crown 

(of deciduous trees). 

Dbh.-Diameter at breast height. The approximate height (4~ ft above the ground) which is standard for 

diameter measurements of tree trunks. 

Deciduous tree.-Tree, such as oak and hickory, which normally produces new leaves every spring, loses them 

in the fall of the same year, and overwinters in a leafless condition. 

Dendrograph.-Instrument attached to a tree to obtain continuous records of radial growth (actually, radial 

change) and to record the measurements on a chart automatically. 

Dendrometer.-A nonrecording instrument used to obtain periodic measurements of change in a radius of a tree 

trunk. 

Diffuse-porous wood.-Wood in which the vessels are of fairly uniform size and distributed throughout each 

annual increment, as in red maple and birch. 

Earlywood.-Inner part of an annual ring which, in a ring-porous species, contains much larger vessels than are 

in the outer, or latewood, part of the ring. Earlywood is recognized in diffuse-porous and nonporous woods 

by density, cell size, cell-wall thickness, and color variations. 

Growth.-Increase in size by addition of new cells or cellular material. 

Growth regulators.-Organic compounds produced by the tree, which increase and (or) decrease growth rates by 

affecting physiological processes which control cell division, enlargement, and differentiation. Auxins and 

hormones are examples of growth regulators. 

Internode.-That part of a stem between nodes. 

Latewood.-The outer part of an annual ring. See "earlywood." 

Main stem.--The stem along the main axis of a tree which is or may become part of the tree trunk. 

Node.-The point on a stem at which leaves and (or) branches arise or have arisen. 

IV 
GLOSSARY v 

Nonporous wood.-Wood of conifers which does not contain vessels, as in pine or hemlock. 

Phloem.-Food-conducting tissue which constitutes most of the inner bark and is located between the cambium 

and the outer bark. 

Radial growth.-Increase in radius at a given height. Total radial-growth increment of a given year (minus 

bark increment) is ring width of that year. 

Release.-A change in the external environment of a tree that reduces competition with other trees, as would 

result if the surrounding trees were removed. Decrease in suppression. 

Ring.-Two-dimensional cross section of an annual increment. 

Ring-porous wood.-Wood in which the vessels are of two distinct sizes, the larger being only in the inner (earlywood) part of the annual increment, as in oaks and hickories. 

Stem.-Any of the above-ground parts of a tree which bear or have borne buds a:p.d leaves. The trunk and all 

branches are stems. 

Subcanopy.-The lower part of the forest canopy. Trees located in the subcanopy are those whose crowns 

reach the lower level of the forest canopy. 

Suppression.-A condition of growth retardation usually associated with competition. 

Terminal growth increment.-An annual increment of longitudinal growth of the main stem. 

Trunk.-The main stem of a tree; generally the branch-free part below the crown. 

Xylem.-Water-conducting tissue of most plants and supporting tissue (wood) of trees. Develops inward front 

the cambium. 

VEGETATION AND HYDROLOGIC PHENOMENA 

ANNUAL GROWTH OF SUPPRESSED CHESTNUT OAK AND RED MAPLE, 

A BASIS FOR HYDROLOGIC INFERENCE 

By RICHARD L. PHIPPS 

ABSTRACT 

Three-dimensional shape of individual annual xylem growth 

increments was ascertained from dissected ring-porous chestnut 

oak and diffuse-porous red maple trees from a native forest in 

southeastern Ohio. The increments are near para·boloidal, local 

deviations from true paraboloid shape ·being characteristic. The 

red maple rings (in transverse cross section) are widest near 

the base of the crown, but display only a slight ·basipetal increase 

in cross-sectional area. An entire ring of ·red maple appears 

somewhat analogous to the latewood of chestnut oak, the earlywood of c-hestnut oak being unlike that of red maple. The width 

of earlywood of chestnut oak does not decrease, or decreases 

only Rlightly basipetally, and is thus associated with a pronounced basipetal increase in total ring cross-sectional area. 

Chestnut oak earlywood cells are hypothesized to have origiHated prior to the current growth season. Earlywood growth 

thus appears to be affected by an entirely different set of hydrologic conditions than red maple ring growth and chestnut oak 

latewood growth, which occur in late spring and early summer. 

Annual ring growth of red maple and latewood growth of 

chestnut oak appear to occur at a suc-cessively later time in the 

growth season with distance from the top of the tree. Since 

water, probably the most limiting factor to growth, is appaTently 

not typically in limiting s upply during the early part of the 

growth season, little or no growth reduction occurs in the upper 

part of the tree during even extreme drought years. However, 

growth reduction throughout the tree may occur during the 

year after a drought, as a r esult of the p·hysiological damage 

caused by the dro~.1ght. Suppression. such as is induced by encroachment by surrounding trees, results in a similar decrease 

in growth at all heights which may be erroneously interpreted 

as resulting from several successive years of drought if rings 

from only one trunk leyel are examined. Release from suppression by surrounding trees and release from drought may possibly be distinguishable if ring patterns from more than one 

level in the trunk are examined. The interrelationships between 

earlywood and latewood formation in chestnut oak and the 

causal factors pursuant to variations in size of earlywood are 

not understood. 

Discontinuous or missing rings are noted in annual rings of 

red maple and in the latewood of chestnut oak, primarily in the 

lower parts of the trunk during years of less than typical 

amounts of growth. Trees not severely suppressed would be 

expected to contain few ring discontinuities, and thus would 

contain rings more suitable for analysis in regard to climatic 

conditions. It is botanically impossible for an annual ring to 

be missing throughout the entire length of the tree, and no 

evidence was found to indicate discontinuous earlywood growth 

of chestnut oak. 

INTRODUCTION 

A thorough understanding of the relationships between the growth of trees and their hydrologic environment is necessary before tree rings may be utilized 

with any degree of reliability to infer hydrologic conditions. The achievement of such an understanding is 

far from simple. Dobbs (1951) stated that, in general, 

botanists and foresters "* * * have shown the least interest in the remarkable record which the tree leaves 

behind it in the wood. This is understandable because 

it is they who are most likely to realize the complexity 

of that record." Glock (1955) in a review on the subject, stated that"* * *more and more* * * all workers 

have become impressed with the multiplicity of factors, 

the complexity of their interactions, and their detailed 

areal variability." 

The purpose of this report is to describe ring growth 

of two deciduous tree species from measurements at 

several positions along the trunks. From these descriptions, several hypotheses will be presented concerning 

various influences of the hydrologic environment on 

ring form and size. This report is of a very limited 

and generalized study, which serves as the foundation 

of a more extensive and intensive research program. 

The ultimate objective of the program is the accurate 

estimation of hydrologic conditions from tree-growth 

records (rings) . If successful, long-term ring records 

can be used to extend hydrologic histories in time prior 

to current records wherever trees of sufficient age still 

exist. Short-term ring records, which are readily available, may be used to estimate recent environmental conditions in areas where no hydrologic or climatologic 

data are available, such as in most first- and secondorder stream valleys. Analysis of tree rings can also 

Cl 
C2 VEGETATION AND HYDROLOGIC PHENOMENA 

be used in studies of changes in environmental conditions other than hydrologic, such as are brought about 

by acid mine drainage and changes in land usage. 

ACKNOWLEDGMENTS 

The study was conducted through the facilities of the 

N eotoma Ecological and Bioclimatic Laboratory of The 

Ohio State University. During the study, the laboratory was supported by the U.S. Atomic Energy Commission (contract No. AT ( 11-1) -552) through the 

Ohio Agricultural Experiment Station. Appreciation 

is expressed to the director of the laboratory, 

Dr. Gareth E. Gilbert, for his support and encouragement. Appreciation is expressed also to the owner of 

Neotoma valley, Dr. Edward S. Thomas, for the use 

of his land and for permission to remove the four trees 

utilized in these studies. 

This report is hased on parts of a thesis presented in 

partial fulfillment of the requirements for the degree, 

Doctor of Philosophy, at The Ohio State University. 

Several members of the Department of Botany and 

Plant Pathology of The Ohio State University contributed helpful criticisms and suggestions at various 

stages in the research. ,Jerry A. Koch, Ronald L. 

Laughlin, and Victor L. Riemenschneider, of the Neotoma Laboratory, were particularly helpful in interpretations of related studies. 

\V"ithout the special interest and support of Robert 

S. Sigafoos in all phases of the study, the expeditious 

completion of the work would not have been possible. 

THE STUDY AREA 

These studies were conducted in southeastern Ohio 

in a small valley named N eotoma, located in NE~ sec. 

16, Good Hope Township, Hocking County (long. 

82°33'18" W.; lat. 39°35'55" E.). The valley has been 

the location of ecological studies since the purchase of 

the land by Edward S. Thomas in 1922. Extensive 

microclimatic studies were begun by Wolfe and associates in the late 1930's (Wolfe and others, 1949). More 

recent ecological and bioenvironmental studies (Wolfe 

and Gilbert, 1956; Gilbert, 1961, 1964) have been primarily concerned with the central part of Neotoma, but 

have also resulted in detailed descriptions of bedrock, 

soils, glacial deposits, and vegetation of the entire 

valley. 

Neotoma lies just inside the western escarpment of 

the dissected Appalachian Plateau in southeastern 

Ohio. Bedrock of the Neotoma area is of two formations of Mississippian age, Logan and Cuyahoga 

(Wolfe and others, 1962). At N eotoma the sandstone 

of the Logan caps the underlying Black Hand Sandstone, but little of the Logan remains. Slight eastward 

dipping of all strata has affected the soil-moisture distribution (Laughlin, 1964) and the vegetation distribution in the valley (Koch, 1964). 

Vegetation and distribution of soil types illustrate 

the diversity of habitats on the opposing slopes (figs. 

I, 2). Generally, the upper slopes are dryer and contain coarser soils than the lower slopes, and the southwest-facing slope is dryer and has a somewhat more 

shallow soil than the northeast-facing slope (Riemenschneider, 1964). 

A forest in which more than a third of the canopysized trees are chestnut oak occupies the upper fourth 

of the southwest-facing slope, the driest site below the 

rock cliffs. (Nomenclature of trees follows that used 

by Little ( 1953).) The soils of the chestnut oak area 

are a stony phase of DeKalb sandy loam, having internal drainage probably faster than in the DeKalb soils 

downslope. 

Below the chestnut oak on the southwest-facing slope 

is a forest of mixed oak trees. American chestnut was 

an important member of the forest until its death in 

FIGURE 1.- Lower northeast-facing slope vegetation (looking northward) through which cross-vnlley transect passes. Photograph by 

Alan Heilman, Ohio State University, Octaber 1958. 
ANNUAL GROWTH, SUPPRESSED CHESTNUT OAK AND RED MAPLE C3 

FIGURE 2.-Middle southwest-facing slope vegetation looking northwest from area through which cross-valley transect passes. Photograph 

by Alan Hellman, Ohio State University, October 1958. 

the late 1930's and early 1940's. Dominant canopy 

members now include scarlet oak, black oak, white oak, 

chestnut oak, and red maple-trees that were already 

present in the forest. 

The upper northeast-facing slope is occupied by a 

forest consisting mostly of chestnut oak, yellow poplar, 

and red maple. This forest grows on a N eotoma sandyloam soil which is typically wetter than the DeKalb 

soil of the oak forest of the opposite slope and dryer 

than the N eotoma sandy loam of the lower northeastfacing slope. N eotoma is a name recently proposed as 

a new soil series for which Neotoma valley is the type 

location (Finney, 1959). The forest growing on the 

lower northeast-facing slope is the most luxuriant forest 

type of the area. Canopy dominants include red oak, 

red maple, chestnut oak, American beech, white ash, 

butternut, white oak, sweet birch, black cherry, and 

yellow poplar. Canopy associates include eastern hemlock, mockernut hickory, black gum, sassafras, sugar 

maple, and black walnut. 

THE STUDY TREES 

DESCRIPTION OF TREES 

A 20-meter-wide transect was established across the 

valley from the southwest-facing cliff to the northeastfacing cliff. The transect "·as established for several 

uses in the overall tree-growth research program, a part 

of which is described in this report. All the trees of 

1-inch dbh (diameter at breast height) and larger along 

a 20-meter segment of the transect near the middle of 

the southwest-facing slope are represented diagrammatically in figure 3. The figure illustrates the relative 

243-554 0-67-'-2 

density of tree stems and layering and overlapping of 

crowns. The crown density was greater on the opposite 

slope. Across the entire transect, chestnut oak and ted 

maple are the most numerous trees. Red maple, in 23 

of the 34 plots of the transect, and chestnut oak, in 18 

of the 34 plots, were chosen as the species for study. 

Red maple is a fast-growing deciduous species typically associated with moist habitats, such as flood-plain 

forests, but capable of reproducing in a wide range of 

habitats in southeastern Ohio. Chestnut oak is the 

major tree species in forests on most dry ridges in sandstone areas of southeastern Ohio. Chestnut oak is not 

found on flood plains, as red maple is, but grows in many 

valley-slope forests. Red maple is a diffuse-porous 

species; chestnut oak is ring porous (see glossary). 

A red maple and a chestnut oak were felled on each 

of two opposing slopes of Neotoma valley. Three of 

the trees were felled in September 1962. The fourth 

tree, a chestnut oak growing on the northeast-facing 

slope, was felled in February 1964. The four felled 

trees were subcanopy size and thus were expected to be 

characterized by a greater degree of suppression than 

canopy-sized trees. It was hypothesized that trees subjected to a high degree of suppression would be most 

likely to yield climatically "sensitive" rings, assuming 

that growth response to change in climatic factors 

would be magnified under conditions of growth stress. 

Thus, it was hoped that suppressed trees growing in the 

center of their range might be somewhat analogous to 

"sensitive" trees growing near the limits of their range. 

Red maple RM- 18 was in the subcanopy level of the 

lower northeast-facing slope of the sampling transect. 
C4 VEGETATION AND HYDROLOGIC PHENOMENA 

FIGURE 3.- Part of cross-valley transect on southwest-facing slope which included two of the trees felled for dissection. (l'he felled trees 

were a red maple (Ri\i-61) and a chestnut oak (C0-37), shown with a dashed outline. Other trees are indicated as follows : CO, chestnut oak; Rllf, red maple; BO, black oak; WO, white oak; BA, bigtooth aspen; SW, sourwood; DW, dogwood·; BG, black gum. 
ANNUAL GROWTH, SUPPRESSED CHESTNUT OAK AND RED MAPLE C5 

Rl\I-18 was overtopped by, and leaning slightly away 

from, a 16-inch dbh white oak canopy tree about 11 feet 

upslope and to the northwest. Two other canopy trees, 

a 10-inch mockernut hickory and a 9-inch white oak, 

partially overtopped RM-18. Removal of RM-18 

made no hole in the canopy-evidence that all of the 

crown was overtopped. The main stem was forked at 

about 10 feet from ~he live top. One branch, about 

16 feet in length, was dead. Death of the branch may 

have been attributable to oyertopping by surrounding 

trees. The live branch may not have begun growth 

until after death of the other branch. Probably at least 

as ecologically significant in reducing soil moisture as 

the shading of RM -18 was the indirect effect of the 

large white oak upslope. 

Red maple RM-61 was a subcanopy tree near the upper limit of the mixed oak forest of the southwest-facing slope (fig.3). Likeitscounterpart (RM-18) on the 

opposite slope, RM-61leaned slightly away from a large 

16-inch dbh white oak canopy tree about 15 feet upslope. 

Also within 15 feet were two canopy-sized black oaks, 

but most overtopping was by the white oak with a 

spreading crown more than 30.feet in diameter. Unlike 

RM-18, it appeared that at least part of the RM-61 

c.rown was exposed to direct sunlight, and no death of 

major branches was noted. 

Chestnut oak C0-58 was a subcanopy tree on the upper northe:ast-facing slope. It leaned away from, and 

was overtopped by, a double-trunked canopy-sized chestnut oak about 20 feet upslope. It leaned into the lower 

part of the crown of an 8-inch dbh canopy-sized black 

oak about 8 feet away. Some of the terminal branches 

of C0-58 that were enmeshed in the black oak crown 

were dead, and lateral branches had become terminal 

leaders. The height of the dead branches was just above 

30 feet. No samples were taken above this height. 

Chestnut oak C0-37 was a subcanopy tree on the 

southwest~ facing slope (fig. 3). It leaned slightly a way 

from, and was only partially overtopped by, the same 

large white oak tree that almost compltely overtopped 

RM-61. Other than the white oak, the closest tree of 

any size was an 8-inch canopy-sized black oak about 16 

feet upslope. The crown of C0-37 was probably more 

directly exposed to solar radiation than the crowns of 

any of the other three sample trees. 

A brief comparison of the four study trees follows: 

Red maple Chestnut oak 

RM-18 RM~l C0-58 C0-37 

------------1-------------

dbh_ --- __________________________ inches __ Branch-free height __________________ feet__ Total height__ _____________________ do ___ _ Estimated crown diameter ________ do ___ _ Age _______________________________ years __ 

4 

33 

45 

10 

67 

3 

24 

32 

10 

49 

5 

33 

51 

12 

53 

4 

27 

43 

6 

44 

Average height growth for the entire life of the trees 

was about 1 foot per year for chestnut oak on both slopes 

and about % foot per year for red maple on both slopes. 

Average yearly cross-sectional area increment at breast 

height was greater in the northeast-facing-slope study 

trees than in their southwest-facing-slope counterparts. 

However, inasmuch as such yearly averages of the, trees 

are based on totals of all past main -stem growth, they 

are of value only in comparing present size of the trees. 

If, on the other hand, closeness of other trees, degree of 

overtopping, and death of major branches give some indication of present relative suppression of the trees, 

then, at the time of cutting, the study tre.es RM-18 and 

C0-58 on the moist northeast-facing slope were more 

suppressed than RM-61 and C0-37 on the opposite 

slope. 

MEASUREMENT METHODS 

The trees were cut as close to ground level as practicable, and cross sections 1-2 inches thick were removed 

at 3-foot intervals from the base to above the lowest 

major branching of the crown. Each cross section was 

marked upon removal to show the north side of the, 

standing tree and the top side of the section. The sections were air dried, sanded, and polished. A reference 

line was inscribed with a knife along each radius to be 

measured. 

Recent studies of rings at more than one sample 

height have been performed with red and loblolly pines 

(Duff and Nolan, 1953, 1957; Smith and Wilsie, 1961) 

from which cross sections were taken along the main 

stem halfway between each set of annual branch whorls. 

Because annual terminal-growth increments are distinguishable only near the ends of branches on deciduous trees such as red maple and chestnut oak, sampling 

of every annual terminal-growth increment is not practicable. It was believed that sampling at equidistant 

intervals might provide a means of analyzing growth 

allegedly induced as a result of nutrient or growth regulator gradients or both. 

Ring width of RM-18 was measured along the northand upslope-facing radii (approximately 135° apart). 

Annual-ring width measurements along the two radii 

were of sufficient difference that two additional radii 

were measured. Measurements of sections of the three 

remaining trees were taken along radii of the four major 

compass directions. 

The width of the annual rings in the cross sections 

was measured to the nearest thousandth of an inch by 

the use of a mechanical stage, equipped with a dial indicator. Parts ·of some cross sections were remeasured 

from time to time and at various positions in the range 

of the micrometer, and were always within 0.002 inch 

of the original reading. This slight range indicated 
06 VEGETATION AND HYDROLOGIC PHENOMENA 

FIGURE 4.--.Tree stem illustrating hyp()tbesized three-dimensi()nal relationships between rings and annual increments. 
ANNUAL GROWTH, SUPPRESSED CHESTNUT OAK AND RED MAPLE 07 

that ( 1) the accuracy of readings was consistent 

throughout the range of the micrometer, (2) the measurement cut provided a sufficiently distinct reference 

to allow repetition of measurements, and ( 3) the shrinking and swelling of the dried sections during the period 

of measurements were insignificant. 

GROWTH FORM 

Metzger (1893), a~ording to Larson (1963) ·and 

Biisgen and Munch ( 1929), described tree-stem form 

as virtually that of a beam of uniform resistance to 

bending by wind. The beam thus described is a, cubic 

paraboloid whose cubed dia.meter rut any level is proportional to the distance from that level to the center 

of the tree crown. More recently, Gray (1956) suggested that the main stem of a tree may be described by 

a qua.dratic paraboloid. It should be noted that these 

workers did not describe individual annua,l increments 

as paraboloidal. Duff and Nolan (1953) described the 

characteristic patterns of annual rings in red pine and 

demonstrated that the general pattern from center outward a:t any given height progresses from wide rings to 

gradually narrower rings, •and virtually the sa.me pattern is found in any given annual increment progressing 

from the apex of the tree to the base. These findings 

were confirmed by Smith and Wilsie (1961) in work 

with loblolly pine. Neither Duff and Nolan nor Smith 

and Wilsie discussed the possibility of the paraboloid 

shwpe of individual annual increments or of the entire 

trunk, even though their descriptions satisfy the geometry of para!holoids. 

If it is assumed (1) that the first few rings near the 

top of a small tree are the same shape as the first few 

rings near the top of a canopy-sized tree, that is, that 

the twigs are the same size and (2) that the annual 

increments are paraboloid, then it follows that all rings 

in a tree are of the same paraboloid shape. ~hese assumptions, of course, presuppose that environmental 

conditions, and thus total annual growth, are the same 

from year to year. Under the above assumptions, the 

paraboloid patterns of annual increments of a stem 

grown under constant environmental conditions would 

be as illustrated in figure 4. Ring width of any given 

annua,l increment would be greatest near the apex of the 

annual increment and 'vould become increasingly narrow with distance from the apex. Ring width of the 

centermost annual increment at any height would be the 

same as the width of ·the centermost annual increment of 

any other height at the same vertical distance from the 

apex of that annual inerement, the second ring from the 

center at any height would be the same width as the 

second ring from the center a't any other height, and so 

forth. Thus, ·as illustrated in the two cross sections of 

figure 4, the third ring of the upper cross section is the 

same width a.s the third ring of the lower cross section, 

even though they were not formed during the same year. 

According to the conditions of the hypothesis,· the 

outer surface of any given annual increment would he 

the same sha.pe as that of any other annual increment, 

a,nd growth in length each year, by addition of a new 

annual increment., would be constant. In longitudinal 

section, the parahola shape of the outside of an annual 

increment may be described by the standard parabola 

equation 

(2r) 2=4ay, 

where 2r=parabola width, y=parabola length, and 

a= the constant, focal length. It follows that 

(2r)2 =4a 

y ' 

which satisfies the conditions of a quadratic paraboloid 

as applied to tree stems by Gray (1956). The transverse cross-sectional area of a paraboloid segment defined by the parabola, of equations above is obtained by 

the use of the standard equation for the area of a circle, 

A=7T'r. 

In cross section, ring area of a given ring, n, becomes 

the difference in area between the cross section of the 

base of a paraboloid segment delimiting the outer surface of the nth annual increment and the cross section 

of the base of a paraboloid segment delimiting the outer 

surface of the preceding annual increment, n-1. According to the hypothesis, the two segments are of the 

same paraboloid. If growth in length is a constant, s, 

from year to year, then sn= length of the paraboloid 

segment delimiting the outer surface of nth annual increment and s ( n-1) =length of a paraboloid segment 

delimiting surface of n-1 annual increment, and 

and 

Therefore, the cross-sectional area of the nth ring, Rn, is 

Rn=An-An-1 

= ( 1r1'n2)-( 7r1'n-12

) = 1r(1'n2

-1'n-12) 

= 1r[asn--as( n-1)] = 1r( asn-asn+as) 

=7ra8. 

Repeating the procedure for the area, of the n -1 ring 

yields 

Rn-1=An-1-An-2 

= 7r(1'n-12-1'n-22

) 

=1r[as(n-I) -as(n-2)] 

=7ra8. 
C8 VEGETATION AND HYDROLOGIC PHENOMENA 

Thus, the cross-sectional area of any ring, Rn, is equal 

to the cross-sectional area of the preceding ring at the 

same height, Rn_ 1 , providing that the annual increment 

of growth in length, s, remains constant. The same 

type of reasoning further indicates that the cross-sectional area of any ring at any height in the trunk should 

be the same as the cross-sectional area at any other 

height or in any other annual increment. This pattern 

is in agreement with the general statement of Pressler 

(1864) as noted by I. .. a.rson (1963) that"*** in all parts 

of the branch-free stem, ring area growth will be the 

same." Pressler apparently did not suggest a parab- _ 

oloid shape of individual annual increments. Jaccard 

(1912) assumed that a constant cross-sectional area of 

a given annual increment at all heights was necessary 

so water conduction along the stem would not be impeded. It is doubtful that Jaccard considered a constant cross-sectional area between rings at the same 

height. The equations above show that annual increment volume of any segment would be equal to the volume of any other annual increment segment of equal 

length. If the basic annual increment pattern can be 

shown to be paraboloidal, then the paraboloid could be 

a useful tool as a mathematical model in analyses of 

tree rings and annual increments. 

ANNUAL INCREMENTS IN RED MAPLES RM:-18 

AND RM:-61 

Examination of the ring width sequence of a cross 

section of any level in the trunk of a tree reveals a time 

trend in ring width from wider rings near the center to 

narrower rings with increasing distance from the center 

(Douglass, 1936). If sequences of trees of various ages 

are plotted together by year of ring formation, interpretation of data of individual years is confounded because the center rings of one tree (inherently wide) 

may have been formed during the same years that the 

outer rings (inherently narrow) of another tree were 

140r-------~~----------------~----------------~----------------.-----------------.---~ 

100 

"' I 

8 Height, in feet, of sample section X 

en 

UJ 80 "'""'0- 30 :::c 

() ~ 24 ~ 

~ ~18 

:i -<Ir- 12 1-

Cl 60 -o- 6 ~ 

"' z 

a:: 

40 

1920 1930 1940 1950 1960 

YEAR OF RING FORMATION 

FIGURE 5.-Ring-width sequences of red maple R:\1-18 plotted by y~ar of ring formation from cross sections at 6-foot intervals. Data 

an, aY~>rnges of mea:mrPments along four rad.U: north-facing, 112~, 225° (upslope-facing), an<l 337°. Date of center ring at each 

measurement: 1914 (6ft), 1919 (12ft), 1924 (18ft), 1927 (24ft), and 1932 (30ft). 
ANNUAL GROWTH, SUPPRESSED CHESTNUT OAK AND RED MAPLE C9 

lOOr-------------------~--------------------~-------------------.--------------------r----. 

Height, in feet, of sample section 

80 ~ 24 

-e-- 18 

"' -<D- 12 I 

8 -o- 6 

X 

(.f) 60 LLJ 

I 

u 

~ 

~ 

:i 

1-

Cl 40 ~ 

(!) 

z 

ii: 

20 

YEAR OF RING FORMATION 

FIGURE 6.-Ring-w.dth sequences• of red maple RM-61 plotted by year of ring formation from cross sections at 6-foot intervals. Data are 

averages of measurements along radii of four major compass points. Date of second ring from center at each measurement height: 

1921 (6ft), 1924 (12• ft), 193-4 (19·% ft), and 1938 (24ft). 

formed. The same confusion is observed if ring sequences from several heights in a tree are plotted together (figs. 5, 6), because since center rings at an upper level were formed during the same years as outer 

rings in the lower levels. Further complications arise 

if the inner rings at the upper levels are not inherently 

wide, as is apparently true of trees of the southwestern 

States (H. C. Fritts, written commun., December 1965). 

Alinement of sequences from a single tree by ring 

number from the center of each cross section superimposes the time-trend curves. Such an alinement for 

red maple RM -18 is presented in figure 7 from 

sequences of figure 5. Alinement would permit examination of the shape of the time-trend curve, if the 

curve is approximately the same shape at all stem 

heights. Superimposed on the sequence graphs of figure 7 is a smooth curve representing ring widths determined from a series of perfect quadratic paraboloids 

of the shape delimited by the height and basal diameter 

of red maple RM -18. The smooted curve thus represents the ring width sequence that RM-18 would have 

had if ( 1) the annual increment of height and of crosssectional area from year to year had been constant during all of the 50 years represented, if (2) annual increment form were perfectly pa.rabolic, and thus if (3) 

the ti:me-trend curves '"ere the same shape for cross 

sections at all stem heights. The greatest deviations 

from the smooth curve are the three peaks at rings 4, 9, 

and 13, and the apparent absence of growth at rings 

28, 31, 36, and 41. Figure 5 indicates that the three 

peaks of figure 7 all occurred between 1925 and 1927 

when growth at all levels was great. Figure 5 also indicates that all four growth minima occurred during 

1954. If these instances of extreme growth were removed from figure 7, the rest of the data would approximate the smooth curve closely enough to suggest 

that, notwithstanding environmentally induced yearly 

variations in height and radial growth, annual growth 

increment may be somewhat parabolic. 

Data from red maple RM-61 (fig. 6) were also replotted by ring number from the center of each crosssection and are presented in figure 8 along with a smooth 

curve from data of a series of perfect paraboloids. 

Again, the ring-width data have some correspondence 

to the smooth curv~. The most striking deviations occur after the 23d ring. After that point, growth is 

eonsistently below the smooth curve, but reference to 

figure 6 indicates that all the rings formed after 1943 
ClO VEGETATION AND HYDROLOGIC PHENOMENA 

140.---------------.-----------------~----------------r---------------~r-----------------n 

120 

"' I 

0 

...... 

X 

Height, in feet, of sample section 

~30 

--&- 24 

~18 

-<Ir 12 

--o- 6 

~~------------~1~0r---------------~2~0------------~--~~~----~-&----~~------------~~ 

RING NUMBER, FROM CENTER OF CROSS SECTION 

FIGURE 7.-Ring-width sequences of red maple RM ..... 18 plotted by ring number from center of cross section. The sequences are identical 

to those of figure 5 plotted by year of ring formation. The smooth curve represents a ring width-sequence determined from a series 

of paraboloids. 

were restricted in size. Something happened during or 

after 1943 which subsequently suppressed growth. 

An indication of the genera] stem shape or form of 

the two red maples is presented in figure 9. Average 

radius at each sample height is plotted for 10-year intervals, and the date of the center ring at each sample 

height is also included. Horizontal exaggeration of the 

figure is 36 times and consideration of stem form as 

anything other than cone-shaped seems unjustifiable. 

However, other than the 0- and 3-foot levels of RM-61 

which are considered as butt swell, width of the 10-year 

increments is generally greatest at the top-a feature 

that supports the paraboloid hypothesis. 

An indication of changes in the rate of ye.arly height 

growth was obtained by noting the date of the center 

ring at each sample height in the study trees (fig. 10). 

All four trees were apparently growing rapidly in 

height by the time each was 6 feet tall, but the maples 

took considerably longer to reach this height than did 

the oaks. R.M-18 appears to have remained in the. forest understory for at least 20 years before commencing 

rapid height growth. Rate of height growth of all 

four trees appears to have declined at about the time the 

trees reached the lower part of the forest canopy ( approximately 25 feet). Death of uppermost branches 

of RM-18 and C0-58 occurred above the 25-foot height. 

According to the hypothesis of paraboloid shape, if 

yearly growth rate of a tree is constant, then the crosssectional area of all rings (ring-area growth, R) is a 

constant, the time trend being a straight line parallel to 

the abscissa. Early workers who described trunk shape 

as parabolic agreed that within the crown the form of 

the main stem probably more closely approximates that 

of a cone than a paraboloid (Biisgen and Miinch, 1929). 

Larson ( 1963), citing Pressler ( 1864), stated " * * * 

ring area growth (cross-sectional area of a single annual 

increment) at any given point on the stem is proportional to the quantity of foliage above this point." 

Thus, the point of maximum ring width would not be at 

the top of the tree as suggested in figure 4, but near the 
ANNUAL GROWTH, SUPPRESSED CHESTNUT OAK AND RED MAPLE 011 

100.-----------------.-------------------~------------------~------------------T-------

"' I 

0 

..... 

X 60 en 

LLI 

::I: 

() 

z 

~ 

Height, in feet, of sample section 

~ 24 

~ 18 

~ 12 

~6 

RING NUMBER, FROM CENTER OF CROSS SECTION 

FIGURE 8.-Ring-width sequences of red maple RM-61 plotted by, ring number fr()m center of cr()SS section. rr'he sequences are identical 

to those of figure 6 plotted by year of ring formation. The smooth curve represents a ring width sequence from a series of paraboloids. 

base of the erown. Duff and Nolan (1957) found that 

the point of maximum ring width was in the region of 

the crown base but that the exact position varied slightly 

from year to year; it was lower in years of accelerated 

radial growth and higher in years of restricted radial 

growth. 

Ring-·area growth, calculated from data of figures 7 

and 8, are presented in figures 11 and 12. Ring-area 

growth from a series of perfoot paraboloids defined hy 

the height and basal diameter of the tree is included in 

each figure as a dot!ted line. Each dot thus represents 

ring-area growth of a single ring -at uny height and is 

equal to the average yearly ring-area growth at basal 

diameter height. Ring-area growth of the two red 

maples is indicated as consistently below hypothetical 

values for the first 4-6 rings. The combined data of the 

center six rings of figures 11 and 12 include rings representing ·all years from 1914 through 1942. It seems 

improbable that reduced growth of the first 6 rings at 

each level is the result of environment only. The first 

few rings at the center of each sootion would have been 

near the top of the tree when they were formed. T'hus, 

in the upper levels of each annual increment, growth 

apparently is reduced from that of the hypothetical 

paraboloid shape. It could not be determined if stem 

243-554 0---67-3 

shape in the crown were cone shaped as suggested by 

earlier workers, but the growth curves indicate crown 

shapes more conelike than parabolic. The outer rings 

of the maples (figs. 11, 12) also appear to be reduced 

somewhat from the hy,pothetical paraboloid shape. 

Restricted growth in red maple RM-61 is probably associated with a change in the immediate environment of 

the tree during or shortly after 1943. In red maple 

RM-18, some of the outer rings appear to have been 

restricted hut other outer rings were considerably 

greater :than average size. In general, though, both the 

upper (lower ring numbers) and lower (higher ring 

numbers) parts of the stem appear to be somewhat 

constricted, relative to 'a perfect parabolic shrupe. The 

constrictions are in the tree crown at and above center 

of photosyntJhetic activity, and at the base of the tree, 

the stem part ·farthest from the photosynthetic source. 

Or, in other terms, the upper constriction is in the 

proximity of only a fraction of the stem t.ips where 

growth regul~ators presumably are formed. The upper 

central part is at or near <the base of the crown (a:pproximately equidistant from nil stem t.ips) where the 

highest concentration of growth regulators might ·be 

expected, and the lower constriction is farthest from ,au 

the stem tips. 
C12 VEGETATION AND HYDROLOGIC PHENOMENA 

0 

z 

RM-61 

24 

21 

191 lz 

5 15 a:: 

" UJ 

> 0 

co 

II 

1937 ,, I 

1935 

1933 

I 

I 

I 

I 

' I 

I I 1925 

"'- 12 --------,,....,_,t----t-----1923 1--

UJ 

UJ 

LL.. 

, 

I 

6 ---+f----t--+---r-'1920 

2 0 

1934 33 

RM-18 

1932--+--+-+--- 30 

0 

z 

(/) 1926 --+---l---+-..--- 21 5 

" a:: z " 0:: ..... ..... .......... w 

1.0 2 ~~ > 5 ~ o·oO g I- ~ 

~ 1924- 18 ~ 

u w 

' 191 ~----lt----+---H--12 

1916--\---1------t--H- 9 

-+----+--+-+-- 6 

UJ 

LL.. 

AVERAGE RADIUS, IN INCHES 

FIGURE 9.-stem sha·pe ()f red maples RM-18 and RM-61 at 

10-year intervals. 

Area increments of individual rings of the two maples 

are presented in figure 13 for the years 1927-32. Also 

included in the figure is a bar graph of evapotranspiration deficit for the late spring, early summer, and midsummer seasons of the same years. The greater the 

water deficit, as indicated by the evapotranspiration deficit, the more reduced the growth near the bottom of the 

tree. "\Vater deficit appears related to the basipetal 

ring-area trend. This relationship in turn suggests 

either that growth occurs later in the lower part of the 

tree than in the upper, or that growth stops first in the 

lower part. Most of the outer rings (higher ring numbers) of the two maples (figs. 11, 12) were smaller than 

the hypothetical situation. 

1--

UJ 

UJ 

LL.. 

Iii I ti 0 

RM-18 I lro· 

C0-58 From northeast-facing slope I I g / 

0 RM-61 I I~ / 

• C0-37 From southwest-facing slopil !// 

I A I /I 

I / I 

I / 

I / 

P// 

1910 1920 1930 1940 1950 1960 

YEAR OF CENTER RING 

FIGURE 10.-Height growth of the four sample trees, plotted as 

year of center ring at each sample height. 

Ring growth is the result of successful cambial-cell 

divisions and enlargement and differentiation of the 

cells thus derived. Growth is initiated each spring at 

or just beneath the actively developing buds at the 

branch tips, and progresses basipetally throughout the 

tree. It is generally agreed that the basipetal "wave" 

of initial cambial divisions progresses slowly in diffuseporous species ( 3-4 weeks from buds to base, according 

to Wilcox, 1962) such as red maple. The bulk of the 

growth near the base of a tree occurs within about 10 

weeks after initiation (Phipps, 1961). If it is assumed 

that growth at other heights in the tree occurs within 

about 10 weeks of the time it is initiated, then it can 

be calculated at least half of the growth at any height 

is occurring at the same time that growth is occurring 

at all heights. However, regardless of the time during 

which growth occurs simultaneously at all levels, growth 

at any given height may be affected by a somewhat different set of environmental conditions representing a 

different part of the growing season from those that 

affect growth at any other height. Each of the three 

cell-growth processes-division, enlargement, and differentiation-is probably controlled by availability of 

carbohydrates and growth regulators in specific quantities. However, as pointed out by Kozlowski (1962), 
ANNUAL GROWTH, SUPPRESSED CHESTNUT OAK AND RED MAPLE C13 

160~--------------~----------------~----------------~----------------.----------------. 

(T) 

I 

8 

en 

UJ 

:::c 

(..) 

z 

UJ 

0::: 

<( 

:J 

0' 

en 

~ 

1:: 

....... 

<( 

UJ 

0::: 

<( 

(.!) 

z 

0:: 

Height, in feet, of sample section 

-0-30 

~24 

-e--18 

--<1>- 12 

-o- 6 

RM-18 

o~--------------~1o~------~------~2~o--------------~~~------~-A----~~------------~5o 

RING NUMBER, FROM CENTER OF CROSS SECTION 

FIGURE 11.-Ring-area growth by ring number . from section center orf red ma,ple RM-1·8 plotted by cross-sectional sequences at 6-foot 

intervals as was figure 5. Solid dots represent ring-area growth of a single ring at any height. 

a correlation between carbohydrate and auxin levels 

cmnplicates a separation of these two as distinct casual 

factors in growth determinations. For simplification, 

then, gro,vth is regarded as the result of a complex of 

interrelated physiological processes, each of which may 

be varied by any of several environmental conditions. 

By further simplification, growth at any particular level 

in the tree is regarded as an expression of surplus photosynthates of the tree at the time growth at that level 

occurred, and is in turn conditioned by the environmental conditions of the tree at that time. Investigations 

concerning the time and rate of growth at various levels 

in the tree are being conducted, and are part of the 

larger tree-growth research program. 

Ten-year ring-area increments calculated from data 

of figure 9 are given in figure 14. As suggested above 

(figs. 11, 12), ring increment is somewhat less at the 

upper than at the middle trunk heights. A regression 

fitted to the average annual ring-area-per-year data of 

RM-18 (fig. 14) appears to be straight line, contrary to 

the implications of figures 11 and 12, and does not indicate a decrease at the lower trunk heights. If it is 

assumed that growth occurs at different times at different levels in the tree, then growth of a single ring would 

not be expected to be constant at all levels because environmental conditions do not remain constant. The 

data to which the regression line (fig. 14) was fitted 

represent average annual ring-area growth (X 10) during a 30-year period. How different the slope of this 

line would be if· it represented data. for more than 30 

years is not known. Because the ring-area (abscissa 

seale) exaggeration of figure 14 is 240 times, it might 

be assumed that ring area is virtually constant at all 

levels. However, the increase in ring area with decreas-
C14 VEGETATION AND HYDROLOGIC PHENOMENA 

100r-------------------~------------------,--------------------,-------------------,------, 

"' I 

8 

X 80 en 

UJ 

J: 

(_) 

z 

UJ 

cr: 

<( 

5- 60 en 

~ 

.,; 

<( ' 

UJ 

cr: 

<( 40 <.!) 

z 

a: 

Height, in feet, of sample section RM-61 

-0-24 

-e--18 

~12 

-o- 6 

RING NUMBER, FROM CENTER OF CROSS SECTION 

I<'IGURE 12.-Ring area growth by ring number from. section center of red maple RM-61 plotted by cross-sectional sequences at 6-foot 

intervals as was figure 6. Solid dots represent ring-area growth of a single ring at any height. 

ing height is significant. For example, average ringarea growth (1930-60) of RM-18 is one-third again as 

great at the 3-foot level as at the 27 -foot level. Thus, 

though ring-area growth apparently is nearly constant 

throughout the tree, a linear increase with distance from 

the top is suggested strongly enough that it can be assumed that the shape of the plotted ring-area growth 

only approaches a paraboloid. · 

Figure 14 indicates a decrease in growth with time in 

both trees, that is, grow·th was greatest during the first 

10-year interval, 1931-40, and least during the last 10-

year interval, 1951-60. This trend seems in agreement 

with the same general trend of a decreasing rate of 

height growth during the same period (fig. 10). It 

might be suspected that as the trees became subjected to 

increased suppression beneath the forest canopy, growth 

in height and growth in diameter would decrease. Because of both the decrease in total incremental growth 

and the basipetal increase in growth of given increments, 

the general trend in ring area at any given height decreases (figs. 11, 12, and 14). Therefore, decreasing 

size of the total xylem increments was the factor controlling the time trend of decreasing ring area at any 

given height in the two suppressed red maples. If the 

trees had not been suppressed, perhaps the total xylem 

increments would not have decreased in successive years, 

and the basipetal trend of increasing ring area could 

have become the controlling influence of the time trend 

at any given height. In such conditions, the time trend 

would have indicated increasing ring area. Further, 

if the trees had been released, the sa:me time trend of 

increasing ring area would have been expected to follow. 

The change from narrow to wide rings might be indistinguishable from the change resulting when an extended drought is broken, if rings from only one height 

in the tree were examined. 

General overall shape of the main stem of each of the 

red maples indicated stem form to be somewhat parabolic. Ring-area distribution in individual xylem increments of the stem deviates strongly from the paraboloid pattern. In general, the upper part of each increment was smaller than that explained as paraboloid, 

and is believed to have been in the crown of the tree at 

the time of formation. The lower part of most increments is also somewhat reduced from that of the perfect 

paraboloid. This reduction is inferred to be the result 

of the conditions of suppression under which the trees 

grew; such a reduction probably would not be apparent 

in trees not severely suppressed. A basipetal trend of 

increasing ring area was noted in most increments, but 

the lower parts of increments formed during marked 

drought years were greatly reduced in size. Decreasing rates of height growth were associated with increasing suppression because such decreases apparently did 

not occur until tree height reached the proximity of the 

lower part of the forest canopy. Concurrent with decreasing rates of height growth was a general decrease 

in total annual increment, also thought to be a result of 

increasing suppression. 
ANNUAL GROWTH. SUPPRESSED CHESTNUT OAK AND RED MAPLE 

Cl 

z 5 15 0::: 

(.!) 

LLJ f5 12 6 al 

<t: en 

LLJ 

1- J: LLJ (.) 

u.. 

LLJ 9 5 ~ 

~ ~ 

~---

6 4 ~ 

J: (3 (.!) u:: Ui LLJ 

J: Cl 

I z ~ 3 3 0 I i= ~ <t: 0::: 0::: 

L-Late spring 

a: 

2 en 

E-Early summer z 

<t: 

M- Midsummer 0::: 

1-

0 

a.. 

<t: 

> 1.1..! 

0 

L E M L E M L E M L E M L E M L E M 

27 

24 

Cl 5 21 0 

0::: 

(.!) 

~ 18 0 

al 

<t: 

1-

~ 15 u.. 

~ 

~ 12 (.!) 

Ui 

J: 

I 9 ~ I 

~ 

0::: 

6 

3 

1927 1928 1929 1930 1931 

RING AREA INCREMENT /11 

0 50 100 

SQUARE INCHES X IQ-3 

FIGURE 13.~Vertical distribution of annual ring-area increment in RlM-61 and RM-18 for 1927-32, and evapotranspiration 

deficit of late spring, early summer, and midsummer sea.sons. 

015 
C16 VEGETATION AND HYDROLOGIC PHENOMENA 

Red maple RM-61 Red maple RM-18 

1.0 

RING AREA/1r,IN SQUARE INCHES PER 10-YEAR INTERVAL 

FIGURE 14.-Ten-year ring-area growth increments of red maples 

RM-18 and RM-61. .A regression line has been fitted to the 

points representing average yearly ring area (X 10) of RM-18 

during the years HH-60. 

Trends in changes of the total size of xylem increments possibly are descriptive of general conditions of 

the tree as influenced by slowly changing factors of environment such as would affect suppression. The basipetal trend of ring areas appears to be an expression of 

climatic conditions at the time of increment formation. 

Thus, the radial time trend at any given height apparently is an integrated expression of both the total size 

trend and the basipetal trend of the increment; therefore, exclusive examination of a radial series of ring 

areas such as obtained from an increment core probably could not be used to decipher the separate influences 

of changing suppression by surrounding vegetation and 

of changing climatic conditions. In theory, a master 

chronology could he used to remove the effects of age 

and suppression from a given radial series of ring 

widths. This procedure presupposes that the series can 

be cross dated with the master chronology and that the 

master chronology was synthesized from a sufficiently 

great number of series to insure that the effects of age 

and suppression have been completely removed. On 

the other hand, the effects of age and suppression probably could be removed subsequent to examination of 

radial ring series from more than one height in the same 

tree. This method would be contingent only on successful cross dating between heights. 

EARLYWOOD GROWTH OF CHESTNUT OAKS 

C0-58 AND C0-37 

The terms "earlywood" or "spring wood" and "la.tewood" or "summer wood" have been extensively used in 

tree-growth literature and have been applied to nonporous, diffuse-porous, and ring-porous woods. Earlywood and latewood were measured separately in the 

chestnut oak study trees, but no attempt was made to 

separate the two in the red maple. Even though earlywood and latewood may be easily distinguishable in 

diffuse-porous xylem, Chalk ( 1937) appears to have conside red the entire diffuse-porous ring as analagous to the 

latewood part of the ring-porous ring. The daily 

radial-growth rate of red maple for a single year may 

be represented by a single peaked curve characteristic of 

diffuse-porous species; that of chestnut oak is a double 

peaked curve characteristic of ring-porous species (fig. 

15). Fritts (1962) has demonstrated with dendrographs that the first peak of growth of ring-porous 

white oak corresponds to the growth of the pore zone, or 

earlywood, of the ring. Dendrometer investigation of 

Phi'Pps (1961) indicated that the ·second-growth peak 

of white oak and chestnut oak roughly corresponds in 

time with the single peak of red maple and beech (also 

diffuse porous) . 

Earlywood growth is apparently initiated almost 

simultaneously at all levels in the trunk in ring-porous 

species a.t about the beginning of bud activity in the 

spring (Priestly and Scott, 1936). It is not known -if 

initiation of latewood growth proceeds in a slow basipetal fashion in chestnut oak as the increment growth of 

red maple characteristically does. If this type of 

growth occurs, then it n1ight take 3-4 weeks for latewood growth initiation to move down the tree. Thus, 

if earlywood growth, which starts simultaneously 

throughout the tree, begins 4-5 weeks earlier at the base 

than latewood, then latewood growth is initiated in the 

crown at about the same time that ea.rlywood growth is 

beginning. This relationship, of course, is impossible 

unless the cells comprising the earlywood layer arealready present in the cambial layer as derivatives at the 

beginning of the growth season. If this hypothesis is 

correct, then the first growth-rate peak indicated by 

dendrometer measurements a.t breast height (fig. 15) is 

not a reflection of cambial-cell divisions, but of cell enlargement. 
ANNUAL GROWTH, SUPPRESSED CHESTNUT OAK AND RED MAPLE Cl7 

en 

LLJ 

J: 

u 

z 

~ 

"' I 

8 

11~------~--------~--------~--------~ 

Northeast-facing slope 

X 8r---r-~~--~~--~--------~--------~ 

en 

~ 7r--+--~~----~--~--------~--------~ u 

z 

~ 

~ 5r-r-~~~------~~~-------+--------~ 

z 

~ 4~--~--~--------~~--~--~--------~ u 

~ 3r---+---~--------~--~~~~--------~ 

cs 

~ 2r--+----~--------~--~~~4+--------~ 

2.0 r--------,-----------.------------.------------, 

en • LLJ ,, 

u J: " .. ~1.5r---~:r'--1r--------~--------~---------4 rl I 

~ i: :\ A ~I.or---~;~·--~;~:--~~~.----~------,-~,--~--~~~~~-4 

~ : : \ " ,' \ ,f: :: 

~o.5r.!r.f,-:~· ~.~·~· ~:~·~:_\~rt-~--~~~---\~·~-+1~\~'~\~ 8 , " : ~ ~ ·, , , ,r-·' ~ : \; \ I \I I I I ~II \\ I\,'\ j ,'\ II ll 1 

~ o~--~--~L_)~-~--·---·~{~~~·~v--------~'~\·~~~--~~,~-

6~-------,----~-----.------------.----------~ 

5r-~--~~~~~~~---------+--------~ 

LLJ -"' I 

~8 3r--------::,.£-\---'~------~-\----l--~o.-+--------~ 

~X 

u 2~----~~--------~--~~--++--------~ 

Late spring Early summer Midsummer Late summer 

6. Chestnut oak o Red maple 

FIGURE 15.-Growth rates (as radial change) of a chestnut oak and a 

red maple on each slope, and precipitation during spring and summer, 

1959. Growth data from Phipps and Gilbert (1001). 

Examination of the dissected chestnut oaks revealed 

no early,vood in the centern1ost ring of any cross section. 

The centermost ring at any level was, during the year 

of its formation, part of the terminal leader. When 

growth in length occurs in spring, the first secondary 

xylem to develop (as a result of cambial activity) appears to be only latewood. Formation of latewood associated with growth in length thus occurs before full leaf 

expansion, which is at the time that early,Yood growth 

occurs at all levels simultaneously. Thus, earlywood 

growth must be in progress near the top of the tree at 

the time that cambial activity in the terminal leaders is 

producing latewood initials. 

The effects of wounding on growth, as described by 

Phipps ( 1961), may be explained on the basis of this 

hypothesis, if it is assumed that the wound hormone 

stimulates cell divisions. Dendrometer screws installed 

in chestnut oaks during the winter dormant period had 

no apparent effect on earlywood growth of the first 

year. Excessive radial growth attributable to wounding was noted only for the latewood of the first year 

and the earlywood of the second year after installation 

of the screws. Excessive growth associated with 

wounding apparently may result from a concentration 

of growth regulators which induce cell division. Thus, 

in accordance with the hypothesis outlined above, excessive cell divisions of earlywood initials would affect 

growth of the second year after wounding, not the first. 

Wareing (1951) debudded ring-porous and diffuseporous trees as a check of the contention that growthinitiating substances originate in the buds. He noted 

no ring formation in debudded diffuse-porous trees except for a short distance below "strong adventitious 

buds." In ring-porous species, new annual-ring formation occurred in both control and debudded trees. 

Wareing (1951) suggested that a reserve of an auxinprecursor was present in the cambium of the ring-porous species prior to the growth season and that some 

environmental condition triggered the conversion of 

precursor to auxin throughout the tree. This conversion, he reasoned, would explain simultaneous growth 

initiation throughout the tree, even when the tree is 

debudded. The new annual ring formation in debudded 

ring-porous species referred to by Wareing probably 

was only earlywood. Earlywood would he expected 

to form in debudded ring-porous species if, as hypothesized above, undifferentiated earlywood cells are 

present in the cambial layer before growth initiation 

in the spring. 

Latewood growth of ring-porous species may be similar to the entire growth ring of diffuse-porous species. 

Further, a number of cambial derivatives may remain 

undeveloped at the end of the growth season. When 

trigge~;ed by some environmental stimulus in the spring, 

these derivatives simultaneously begin to develop into 

earlywood tissue throughout the tree. The first cambial divisions in the spring thus result in latewood initials. Near the branch tips, just below the current year's 

growth in length, earlywood and latewood growth is 

occurring simultaneously, and with increasing distance 

down the trunk, latewood growth is occurring increasingly later relative to the time of earlywood growth. 

The ring-width sequences for both earlywood and 

latewood of C0-58 and C0-37 are presented in figures 

16 and 17. The similarity between the curve for chestnut oak la.tewood (figs. 16, 17) and the curve for the 
100 

80 

I \ \ I ~ Height, in feet, of sample section 

-0-30 

--($)-- 24 

60 -&-18 

"' I 

8 

X 

(J) 

LLJ 

I 

(.) 

~ 40 

~ 

::C 

ICl 

~ 

(!l 

z 

0:: 20 1\ AI\ 

0 o~--------------------~1~o--------------------~2o~--------------------~3o~--------------------4~o--------------------~5~o~~ 

RING NUMBER, FROM CENTER OF CROSS SECTION 

FIGURE 16.-Annual ring-width sequences or earlywood and Iatewood of chestnut oak C0-58 by ring number from cross section center. Data are from cross sections at 

6-foot intervals along the trunk. 

a 

~ 

00 

< tr_j 

0 

tr_j 

~ 1-3 

1-1 

0 

z 

~ t::! 

~ 

~ 

t::! 

~ 

0 

t'l 

0 

0 

1-1 

c 

loti 

~ tr_j 

z 

0 

~ tr_j 

~ 
ANNUAL GROWTH, SUPPRESSED CHESTNUT OAK AND RED MAPLE C1'9 

100.-------------------~--------------------~--------------------.--------------------.--. 

80 

60 

0') 

I 

0 

,....., 

X 

en 

LLI 

I 

u 

~ 40 

~ 

:I 

I0 

~ 

(.!) 

z 

0:: 

Latewood 

Height, in feet, of sample section 

--'\9- 24 

-e- 18 

~ 12 

~6 

C0-37 

o~------------------~1o--------------------~2o~------------------~3~o------------------~4~o~ 

RING NUMBER, FROM CENTER OF CROSS SECTION 

FIGURE 17.-.A.nnual ring-width sequences of earlywood and latewood of chestnut oak C0-37 by ring number from cross section center. 

Data are from cross sections at 6-foot intervals along the trunk. 

total ring width of red maple (fig. 7) is obvious. The 

major difference between the two is in the first few 

rings, red maple characteristically beginning with narrow rings and the first rings of a given sample height 

of chestnut oak characteristically being the widest. 

The earlywood data presented in figures 16 and 17 

suggest characteristics quite unlike either total ring 

growth of red maple or late,vood growth of chestnut 

oak. Earlywood growth generally accounts for considerably less of the total ring width than does latewood, but with increasing age (at any given level) the 

relationship may be occasionally reversed because of 

the greater variability of latewood growth. Indeed, 

lack of variability between levels or between adjaeent 

rings of a given level is a pronounced characteristic of 

earlywood growth. This characteristic is enhanced by 

the fact that earlywood growth was always greater than 

a minimum value ( 4 X 10-3 in. for oak of fig. 18), while 

latewood may even be discontinuous. 

Ring-area growth of chestnut oak late wood (fig. 19) 

is geometrically similar to the total ring growth of red 

rna ple (fig. 11). However, the addition of earlywood 

(fig. 19) results in a slightly different total ring shape. 

The generalized curve for total ring area (fig. 19) do(~S 

not indicate a significant decrease in area with age (of 

a given level), and the parabolic stem shape thus was 

not as constricted at the base as was that of the red 

maples. It might be expected, then, that suppressed 

subcanopy chestnut oaks could be characterized by a 

stem 'vith a greater degree of taper than those of 

suppressed subcanopy red maples. 

DISCONTINUOUS RINGS 

Since the advent of ring-chronology work as a tool 

in recent archeological dating, the occurrence of multiple annual rings (more than one apparent ring per 

year) and the absence of some rings have been widely 

known and extensively documented in the literature. 
C20 VEGETATION AND HYDROLOGIC PHENOMENA 

250r---------------------.---------------------~----------------------.-------------------, 

0 

0 0 

200 Chestnut oak C0-37 

0 

150 

>-

(.) 

z 

LI.J 

::::> 

0 

LI.J 

a:: 

u.. 

100 

50 I 

WIDTH OF EARLYWOOD, IN INCHES X 10-3 

FIGURE 18.-Frequency distribution of earlywood width measurements taken from 1512 locations in chestnut oak co-:n. 

It is generally agreed that dating errors incurred by 

the presence of such irregularities may be eliminated 

by the application of cross-dating techniques to ring 

sequences of many trees from the general geographic 

area of study. In theory, these trees represent growth 

in a wide range of habitats, and not all the trees would 

be expected to develop irregular rings during the same 

years. Thus, by examination of enough trees from 

enough habitats, all ring irregularities could be identified. However, if even one missing ring of a ring 

record is not accounted for, the correlation of that ring 

record with any given climatic parameter is in jeopardy. 

Because of the inherent serial correlation of rings, failure to recognize the absence of a ring would probably 

not destroy a correlation between rings and climate, but 

it would decrease the accuracy of the correlation. In 

studies involving a limited number of trees in an area 

for which a master chronology is not available, other 

methods of identification of ring irregularities must be 

employed. 

Larson (1962) has demonstrated that the occurrence 

of multiple rings in red pine is caused by variation in 

auxin concentrations associated with terminal-growth 

activity. Thus, if terminal growth were stimulated by 

some environmental condition such as drought breakage after the typical growth peak, tissue would be 

formed in the annual ring which would resemble that 

found in the early part of the ring when terminal 

growth is typically quite active. No distinct examples 

of false, or multiple, rings were found at any height in 

the trunks in any of the four study trees from N eotoma. 

Though variations within the rings of the four study 

trees were not distinct enough to be considered as multiple rings, subtle variations in cell size, shape, and 

number were noted. Anatomical variations within a 

ring might provide growth parameters correlative with 

environmental conditions based on time intervals much 

shorter than phenological seasons or calendar months. 

Circumferentially oriented bands of parenchyma in the 

latewood of white and chestnut oak may be an example 

of such an antomical variation. Preliminary examination of parenchyma bands in one of the dissected chestnut oaks ( C0-58) revealed that the number of bands 

per ring and the distance bebveen bands were quite 

variable, but tended to decrease toward the outside of 

the ring, and the number and distribution of bands ap-
ANNUAL GROWTH, SUPPRESSED CHESTNUT OAK AND RED MAPLE C21 

peared to be unrelated to ring width. If production 

of these parenchyma bands is environmentally controlled, then their occurrence would be expected to correlate with enrironmental conditions of periods of much 

less than a phenological season, even at a single sample 

height. 

The upper part of the xylem increments of the four 

study trees was never discontinuous. Though environmentally induced variation in size from ring to ring 

was more or less random, there was, as described above, 

a tendency for all rings to become increasingly narrow 'vith increasing distance from the apex. Some red 

maple xylem increments, which were narrow near their 

apices, tapered down the trunk to the point where they 

completely disappeared on one or more sides of the 

trunk. Rarely was a ring missing on all sides of the 

trunk at any given height, and the ring usually reappeared on all sides of the trunk near the base in the 

region of butt swell. 

Data of discontinuous rings at the 6-foot level of 

RM-18 for the years 1953-62 are presented diagrammatically in figure 20. The data illustrate only the 

order in which the rings occurred; no attempt was made 

to present ring width to scale. In the actual section, 

the hvo radii "a" and "b" were of a single diameter 

bisecting the angle of the other two radii "north" and 

"upslope," which were about 135° apart. The four 

radii in figure 20 were those used for ring measurement 

with the mechanical stage. If the four radii only had 

been used, as would have been done had increment cores 

instead of cross sections been used, the rings could not 

have been dated by a simple ring count. If, by chance, 

the number of rings in each radius had been the same, 

the rings would have been incorrectly dated. 

Even with the entire cross section available for inspection, it is sometimes not possible to ascertain the 

years represented by all rings. For example, in figure 

20, note the discontinuous ring indicated as "unknmvn" 

through which radius "b~' passes. As illustrated, the 

"unknown" ring could have been formed during 1954, 

1955, or 1956. Determination of the actual year of formation requires examination of the cross sections above 

and below, and is based not only on the positions of discontinuous rings in adjacent cross sections, but also on 

the ring widths. For this example, the year of ring 

formation was determined as being 1955. By this 

method, it was possible to date all such "unknown~~ 

rings. 

To illustrate the pattern of discontinuous rings along 

the trunk, figure 21 was prepared from RM-18 data for 

the 6-foot height up through the 33-foot height. Presence or absence of rings was determined at 3-foot intervals, and determination of patten1 between heights was 

by interpolation. Isolated patches or islands of growth 

may have been associated with local wounding. If the 

interpretation of the patterns is correct, several questions are posed. 'Vhat, for example, is the explanation 

of the apparent spiralling of the growth layers~ Horizontal exaggeration of the illustrations is about 35 times, 

so it is at least possible that spiralling is not real. If the 

spiralling does exist, are the tracheae (water tubes) 

oriented similarly~ It is possible that the angle of 

spiralling is induced by some factor such as water stress, 

and that the angle may change from ring to ring, or 

even from level to level in the same ring. 

The amounts of early and midsummer precipitation, 

as shown by U.S. Weather Bureau records from Lancaster, Ohio (9 miles from Neotoma), were below average during 1954 and 1955; rings for these years were 

absent in the middle and lower trunk levels (fig. 21). 

During 1956 when growth was discontinuous in local 

areas of the lower trunk, precipitation was about average in late spring, above average in early summer, but 

belo·w average in midsummer. These results suggest 

correlation between precipitation on a seasonal basis and 

growth at various levels in the tree. 

During 1959, precipitation was below average in late 

spring, greatly above average in early summer, and 

below average in midsummer. Growth was essentially 

continuous throughout the tree, and thus did not correlate with precipitation in the sa.me manner as growth 

during 1956. The tree was growing on a silt loam which 

could act as a partial dam to internal soil drainage from 

the sandy loam soil immediately upslope. Thus, during 

1957, early summer precipitation may have been great 

enough that a considerable amount of water was stored 

above the silt loam and continued to drain into it during midsummer when precipita.tion was low. If this 

condition did prevail, growth ·and precipitation would 

appear to be correlative only if precipitation and soil 

moisture are correlative. 

During 1958, precipitation at Lancaster was about 

average during late spring, about 2% inches above average in early summer, and about 51h inches above (or 

twice) average in midsummer. Growth in the lower 

part of the tree was discontinuous (fig. 21) . This reduced growth was probably the result·of physiological 

drought caused by reduced soil aeration associated with 

high water content of the soil. Again growth 'a.t different levels in the tree was indicated as expressions of 

water conditions of different seasons, but the correlation 

between growth a.nd precipitation is negative during 

part of the year. 

Precipitation during late spring 1962, which was 2112 

inches below (or less than 40 percent of) average, may 

have been low enough to affect discontinuous growth in 
C22 VEGETATION AND HYDROLOGIC PHENOMENA 

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RING NUMBER, FROM CENTER OF CROSS SECTION ~ 

FIGURE 19.-Ring-area growth sequences of earlywood and latewood, and generalized curve <1f total ring-area growth of chestnut oak C0- 58. 

> "d 

t"' 

t'l 

§ 
024 VEGETATION AND HYDROLOGIC PHENOMENA 

111 rnu 111 • 1962 1961 1960 1959 1957 1956 ~ 1955 

FIGURE 20.- Diagrammat!c representation of discontinulty of outer 10 rings at 6-foot level of red maple RM-18. 
ANNUAL GROWTH. SUPPRESSED CHESTNUT OAK AND RED MAPLE 

33 DISCONTINUOUS RING 1954 (RM-18) 

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DISCONTINUOUS RING 1956 (RM-18) 

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DISCONTINUOUS RING 1958 (RM-18) 

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DISCONTINUOUS RING 1957 (RM-18) 

33~~~~.~~~~~~~~~.,~.~,~., 

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33 ~~D~IS~C~O~NT~IN~U~O~US~RFIN=G~1~96~2~(=R=M-=1=8)~~ 

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025 

FIGURE 21.-Diagrams of discontinuous growth of individual rings of red maple RM-18. Ea-ch diagram is of a single ring as would 

be obtained if the ring were split along the south side and laid out flat. Shaded parts represent areas of growth of each sample 

height. Dashed lines are estimations of boundaries between growth and no growth. 
C26 VEGETATION AND HYDROLOGIC PHENOMENA 

the upper trunk levels (fig. 21). Early and midsummer 

precipitation reception of 1962 was similar to that of 

1956 in that early summer was rubove average and midsummer was below. About lj2 inch more precipitation 

was received in midsummer 1962 than in midsummer 

1956; this increase appears correlated with somewhat 

less discontinuous growth in the lower trunk in 1962 

than in 1956. These suggested correlations cannot be 

regarded as conclusive, but they strongly imply that by 

sampling rings at more than one trunk level a more reliable growth measurement for correlation with water 

parameters may be obtained. 

Ring discontinuities 'vere found in both red maples 

and in the latewood of ·the two chestnut oaks. Generally, discontinuous rings occurred at the lower levels of 

the trunks during years when the growth increment was 

small. The number of discontinuous rings in each tree 

was related to the degree. to which each was suppressed 

by surrounding trees. The greatest amount of discontinuous growth was noted in red maple RM-18, the 

most suppressed of the four trees, and the least discontinuous growth was in chestnut oak C0-37, the least 

suppressed. Growth seemed more limited by the immediate environment of each tree (such as implied by 

suppression from surrounding trees) than by factors 

relating to slope exposure or direction of the sun. In 

other words, there was no distinguishable difference between the growth on the north-facing and south-facing 

sides or between the upslope and downslope sides of the 

trees. All four trees were. overtopped to some degree by 

canopy-sized trees, and radial growth of the trunks 

seemed most limited (discontinuous) on the side ( s) of 

greatest suppression. Comparisons of vertical distribution patterns of discontinuous rings with precipitation data strongly suggest growth does not occur at the 

same time throughout the trunk, but at an increasingly 

later time with distance from the top of the tree. 

SUMMARY 

A suppressed chestnut oak and a red maple were felled 

on each of opposing slopes of a small southern Ohio 

valley. Cross sections were obtained at 3-foot intervals 

along the trunks, ring-width measurements were taken 

from each, and growth increments were subsequently 

described. 

The widest ring at any given height was typically 

within the centermost 4-5 rings in red maple and was 

typically the center ring in chestnut oak. Ring width 

was typically greatest near the apex of any given increment and decreased with increasing distance from the 

apex. During periods of suppressed growth from 

drought or other causes, ring width was often restricted 

to the point of absence at the lower trunk heights. 

Earlywood width in chestnut oak remained relatively 

constant in all rings at all trunk heights. Earlywood 

area at any height was thus largely a function of ring 

diameter. Latewood of chestnut oak appeared similar 

to the entire ring of red maple. 

Ring area (cross-sectional area at given height) increased from increment apex to about the lower level 

of the tree crown. Generally, ring area decreased with 

increasing distance downward from the crown during 

drought years, but continued to increase downward 

from crown during nondrought years. Earlywood 

growth of chestnut oak was not necessarily restricted in 

size during drought years. 

Growth seemed to have occurred earlier at the upper 

levels of any given increment than at the lower levels. 

Water apparently was not a limiting factor in the early 

part of any growth season, with the result that growth 

did not appe.ar restricted in the upper levels of the trees 

even during more extreme drought years. 

Because ring growth during successive years at any 

given level becomes increasingly distant from the tree 

top ( rus the tree grows in height), each successive ring 

in a given cross section presumably was formed at a 

later time in growth season. Thus, it would not be expected that all rings in a given cross section could be 

closely and directly correlated with environmental conditions during the same part of the growing season. On 

the other hand, it would be expected that systematic 

analysis of ring data frmn several cross sections at as 

1nany heights could yield accurate correlations with environmental eonditions during ~several parts or short 

periods of a single growing season. 

The earlywood cells of chestnut oak may have been 

cut off from the eambium at some time prior to the current growth season. The earlywood eells appear to 

have then enlarged and differentiated simultaneously 

throughout the tree at the beginning of the growth season. Earlywood thus is suggested to be refleetive of an 

entirely different set of environmental conditions than 

is latewood. Earlywood cell number possibly refleets 

certain eonditions of the previous season and cell size 

certain conditions of the current season. 

The basic growth characteristics of chestnut oak and 

red maple indicate that ring meapurements of individual 

species must be treated independently. But, inasmu~h 

as each species reflects somewhat different environmental conditions, a more complete picture is expected from 

examination of ring gro,vth of several species. 
ANNUAL GROWTH, SUPPRESSED CHESTNUT OAK AND RED MAPLE C27 

LIST OF TREES 

[Nomenclature after that of Little (1953)] 

Ash, white ___________________ Framinus americana L. 

Beech, American _____________ Fagus grandifolia Ehrh. 

Birch, sweet_________________ Betula lenta L. 

ButJternuiL------------------· Juglans cinerea L. 

Cherry, black________________ Prunus serotina Ehrh. 

Chestnut, American ___________ Castanea dentata (Marsh.) 

Borkh. 

Gum, black __________________ . Nyssa 81flva.tica Marsh. 

Hemlock, eastern ____________ Tsu.ga canadensis (L.) Carr. 

Hickory, mockernut__________ Oarya tomentosa Nutt. 

Maple, red ___________________ Acer rubrum L. 

Maple, sugar----------------- A. saccharum Marsh. 

Oak, black ___________________ Quercus velutina Lam. 

Oak, chestnut_ _______________ Q. prinus L. 

Oak, red _____________________ Q. rubra L. 

Oak, scarlet_ ________________ , Q. coccinea Muenchh. 

Oak, white ___________________ Q. alba L. 

Pine, loblolly----------------- Pinus taeda L. 

Pine, red--------------------· P. resinosa Ait. 

Poplar, yellow---------------· Liriodendron tulipifm·a L. 

Sassafras ____________________ Sassafras albidum (Nutt.) Nees 

'Valnut, black ________________ Juglan8 nigra L. 

REFERENCES CITED 

Biisgen, M., and Miinch, E., 1929, The structure and life of forest 

trees (English translation) : New York, John 'Viley & Sons. 

Ch'alk, L., 1t37, A note on the meaning of terms early wood and 

late wood: Leeds Phil. Lit. Soc. Proc., v. 3, p. 324-325. 

Dobbs, C. G., 1951, A study of growth rings in trees. I. Review 

and discussion of recent work : Forestry, v. 24, p. 22-35. 

Douglass, A. E., 1936, Climatic cycles and tree growth: Carnegie 

Inst. Washington Pub. 289, v. 3. 

Duff', G. H., and Nolan, N. J., 1953, Growth and morphogenesis 

in the Canadian forest species. I. The controls of cambial 

and apical activity in Pimts resinosa Ait.: Can. Jour. Bot., 

v. 31, p. 471~513. 

---1957, Growth and morphogenesis in the Canadian forest 

species. II. Specific increments and their relation to the 

quantity and activity of growth in Pinus 1·esinosa Ait. : 

Can. Jour. Bot., v. 35, p. 527-572. 

Finney, Harlan R., 1959, Soil sequence studies in four northwestsoutheast oriented valleys in southeastern Ohio: Ohio State 

Univ. M.S. Thesis. 

Fritts, H. C., 1962, The relation of growth ring widths in American beech and white oak to variations in climate : Tree Ring 

Bull., v. 25, p. 2-10. 

Gilbert, Gareth E., 1961, The Neotoma ecological and bioclimatic 

research program as of 1961: Ohio Agr. Expt. Sta. Research 

Circ. 93. 

0 

GHbert, Gareth E., 1964, Bioclimatic and soils investigations in 

forest environments: Final report to AEC (contract AT 

(11-1)-552), Ohio Agr. Expt. ,sta. and Ohio State Univ. 

Glock, Waldo S., 1955, Tree growth. II. Growth rings and 

climate: Bot. Rev., v. 21, p. 73-188. 

Gray, H. R., 19·56, The form and taper of forest-tree stems: 

Oxford Univ., Imp. For. Inst. Paper, v. 32, p. 1-74. 

Jaccard, P., 1912, La forme des arbres estelle vraiment determim~e par le vent?: Jour. Forestry Suisse, v. 63, p. 129-140. 

Koch, Jerry A., 1964, Vegetation of Neotoma, in Gilbert, G. E., 

ed., Final report to AEC (contract AT(ll-1)-552): Ohio 

State Univ. 

Kozlowski, T. T., 1962, Photosynthesis, climate, and tree growth, 

in Tree Growth: New York, Ronald Press Co., p. 149-164. 

Larson, Philip R., 1962, Auxin gradients and the regulation of 

cambial activity, in Kozlowski, T. T., ed., Tree Growth: 

New York, Ronald Press Co., p. 97-117. 

---1963, Stem form development of forest trees : Forest Sci. 

Mon., v. 5, p. 1-42. 

Laughlin, Ronald L., 1964, Soil moLsture conditions at Neotoma 

with special reference to a period of drought: Ohio State 

Univ. M.S. thesis. 

Little, Elbert L., Jr., 1953, Check list of native and naturalized 

trees of the United States: U.S. Dept. Agriculture. Handb. 

41. 

Metzger, K., 1893, Der 'Vind als massgebender Faktor fiir das 

Wachsthum der Baume: Miindener forstl, v. 3, p. 35-86. 

Phipps, Richard L., 1961, Analysis of five years dendrometer 

data obtained within three deciduous forest communities of 

Neotoma: Ohio Agr. Expt. Sta. Research Circ. 105. 

Pressler, M. R., 1864, Das Gesetz der stammbildung: Arnoldische Bushhandlung, Leipzig, p. 153. 

Priestly, H. H., and Scott, L. 1., 1936, A note upon summer wood 

production in the tree: Leeds Phil. Lit. Soc. Proc., v. 3, p. 

235-245. 

Riemenschneider, Victor L., 1964, Soils of Neotoma: Ohio State 

Univ. M.S. thesis. 

Smith, D. M., and 'Vilsie, M. C., 1961, Some anatomical responses of loblolly pine to soil-water deficiencies: Tappi, v. 

44, p. 179-185. 

Wareing, P. F., 1951, Growth studies of woody plants. IV. The 

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