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THE COMPOSITION AND DYNAMICS OF A
BEECH-MAPLE CLIMAX COMMUNITY

ArTHUR B. Wittiams, Pu. D.

SCIENTIFIC PUBLICATIONS
OF THE
CLEVELAND MUSEUM OF NATURAL HISTORY

Volume VI

First Printed in ECOLGGICAL MONOGRAPHS
Vol. 6, No. 3, July 1936

CLEVELAND, OHIO

SCIENTIFIC PUBLICATIONS

OF THE

CLEVELAND MUSEUM OF NATURAL HISTORY

Volume VI Issued, July 1936

DHE COMPOSITION AND DYNAMICS OF A
BEECH-MAPLE CLIMAX COMMUNITY?

ARTHUR B. WILLIAMS
Cleveland Museum of Natural History

First Printed in

ECOLOGICAL MONOGRAPHS

_ Vol. 6, No. 3, July 1936
Pages 318-408

1 Contribution from the Biological Laboratory of Western Reserve University,

CONTENTS

PAGE

INTRODUCTION [5,05,0% fds i da's oh Slate WP cain cae oscilla Cale Stereo Oss as he eee 3
DescemrTion or Agea Sroupmep |. 2250.22 sc cececennees 6 sca se noes eee e eee 5
Location’ and | physiography... . osc.6 css skeme osieanen ss sees ao ee ee 5
Geolopy ‘and s@ie ccc cucakisis a pice amid sib Se a weielemaeie slemis le etek er eae 6
Drainare. Gnesi es saa ssa os 9 bikhi susie olble's 6 eWiarels's ea oh Oe 7
CRTRGA TE i a ilis ss Reis Ov aie oie Se vic a dia late wld Slaw gidbicte'e alee e dele eee eee 7
T CRIPCTALULE! Fi)! o)0\5.0.0 bole ewe Sales Soe wie 6 wie alu eave acetal oe b letelel ole cin 6 Calera ae 8
Ree la bine! int titty ste chown he Saveroie wed pba lave am tierce aiaene vesadederbess ee 10
PECIPIEAHON) osc cx cs sed CARS ca ieis alain ears c ou bee 6 bad aos cer enie eee 10
WW aaa eae ob are W ccain le a btc wid d& we avararele pteieraleus lee Blais Bip Dota'y le OAs eieie sae id
Sershite 54 des sinc eeu ale Sa ed Sa dee die cele elsigs Mee wis ob amiem alleen tn 13
Pyapordtion: Pate osc ca oeis ied a dee nie ee cee sec elessakaun secu ce cone eee 14
Sammary of climatic data ....ccek. J.)s 5 cece acdc e sow coe care oule sewer 15
ELISToRY OF THE AREA STUDIED 4200505005 cose cdeeeasseessa sees es ane 16
CHAWACTER (OF THE, FOREST) 622). cco. ba ccna ese taecce ah eae as inae ee 17
Plant \ConstititiOn sca nce sc cen wets ke aictae ye ieiSule-éa nieluis.o/a\e\sl ave ea els er 17
Dynamics (OL SUCCESSION! ...12% 6 ose s ca dale ose s oes sees odes sees seen (eee 31
Secondary (Succession: 4.0.0.0. Ne5.. sessile cae cece ne tece eee e dacs Se eee eee 39
Ecological’ classification Of plants 0) ec... ace ec ag sine o 6 e'die 420 ne sees ee eee 40
CHARACTER OF ANIMAL, POPULATION \. 3. ccc 6 0 oc wcities ce euslaisieae we eteiree oe 41
Methods <O8 sShAGY 25 5 oc:g wc Sintec ol ersiaiuis wale talele ois © «erelpieid o oe'S cia cies Se 41
The, mammals of the area. ...... 0.5: jee eae slecinea soles Mee sees aero aa 43
Distribution and abundance of mammals ..............0300.0ss<ss0=0eee eee a4
Bood' chains) and ecological niches. .s..6.6/6 02.66 escent es ccd. csicmeee eee 48
Fluctuations an numbers of, mammals ......0.0.0...0.0eccceesuees sect eee 53
Whe: Dieds.O8 (the area | 21's. 2 See's eiacein cine vs eae ev epaces keuesese seas Oe 57
Distribution and abundance of birds, ...........206s.0css0000000 ee eee 59
Food chains and ecological niches’... 3... 6c.6 cess ck oe dae ws nas ac ORR 63
Seasonal changes in the bird population of the area ..............ccccccecccccus 69
The reptiles of thejatea ° os ohio bs aes cnc see fe cccueseeewases. wade pee tee ee 70
The amphibia LoL the Area, 6 ossc bs ck ije cede oe 6s oe a peeln sso ocs's ae Clan See 7
fnvertebrates OF, The ake!d 26.00. G50 ce.cce ne ahice's acisie tee ee ed.daes eae eee ee en 74
Ecological classification of animals i... 2.0.2.0. ss beaded ce oes sass 6 eee 76
PUSPECT ION | 2's )s abies ohm aod ere cia, 0.5 aml S Ala esate valtye, Sale al Sieie, Sie ie eparieenan sl cikaete aia er 78
PANTS HAND PONTMABS 30 oc s/s cicals sie Sabie aes tislenisecc'es c cieaia’s Saleen ae eee 85
SUMMARY ‘AND CONCLUSIONS. a... siciae wie dos wis ts Geiwaue es bee ks caleee ules hee oe 88

THE COMPOSITION AND DYNAMICS OF A
BEECH-MAPLE CLIMAX COMMUNITY

INTRODUCTION

The approach in this study is to the biotic community as a whole. It is sought
to determine both its plant and animal content; the number and abundance
of species; their relations to each other and to the community as a whole;
seasonal and yearly variations in numbers and activities ; territorial relations ;
food relations; the stage of succession represented; changes now going on;
environmental conditions, including soil and climatic factors; and the ef-
fect of these upon the community.

Special emphasis is laid upon the vertebrates and the major plant forms.
While it has not been possible to treat the invertebrate life as fully as the
plants and vertebrates, some invertebrates have been noted, and are in-
cluded in this paper.

The writer desires here to acknowledge his indebtedness and to express
his appreciation to the Cleveland Metropolitan Park Board for the oppor-
tunity afforded for this study within the Cleveland Metropolitan Park
System, and for many courtesies extended by park officials; to the Cleveland
Museum of Natural History for making this study possible as a piece of
research in connection with its program, and to Mr. Harold L. Madison,
Director of the Museum, for encouragement in it; to Dr. J. Paul Visscher,
Chairman of the Department of Biology of Western Reserve University,
for the privilege of coordinating a study of this kind with the regular work
of the Department, and especially to Dr. S. C. Kendeigh, of the Department
of Biology of Western Reserve University, for his many helpful sugges-
tions and criticisms during the progress of the work and the preparation
of this paper.

The writer’s thanks are also due to Dr. Addie E. Piehl of the Depart-
ment of Biology of Western Reserve University for aid in identifying
mosses, lichens, and algae; and to Mr. Henry M. Beardslee, of North Perry,
Ohio, for similar aid in identifying fungi. To Mr. B. P. Bole, Jr., mam-
mologist of the Cleveland Museum of Natural History, and to Dr. Harry
C. Oberholzer, of the United States Biological Survey, the writer is in-
debted for checking the lists of mammals and of birds, respectively, with
special reference to subspecies names. To Mr. Arthur B. Fuller, of the
Cleveland Museum of Natural History, to whose expert marksmanship the
collection of all of the bats taken in the area is due (for which special per-
mission was given by the Park Board for the purposes of this study),
the writer is also indebted. To Mr. Philip Moulthrop, also of the Cleve-

ai a |

+4 THE CLEVELAND MusEUM OF NATURAL HISTORY = roe

land Museum of Natural History, the writer is indebted for much help in
the collection of small mammals.

It is not maintained that this study is now complete. In a sense it might
be carried on indefinitely and never be complete. It seems desirable, how-
ever, at this time to make available the data thus far collected and to report
the findings.

The beech-maple forest (Fagus-Acer association) is an important eco-
logical division of the deciduous forest formation, which formation at the
coming of the white man occupied so large a part of the northeastern United
States and southern Canada. The deciduous forest has been described by
Transeau (1905), Harshberger (1911), Frothingham (1915), Clements
(1916), Livingston and Shreve (1921), Shantz and Zon (1924), and
Weaver and Clements (1929). Weaver and Clements give the limits of the
deciduous forest formation as running on the north from central Minnesota
along the south shore of Lake Superior eastward to southwestern Quebec
and southern Maine, thence stretching southward into central Georgia,
southern Louisiana, and eastern Texas. The same authors regard the beech-
maple forest as the “typical association” of the deciduous forest formation,
“characterizing its more humid and cooler northern and eastern portions.”

The plant structure of the beech-maple association has been studied in
detail in southern Michigan by Quick (1923) and by Cain (1935), in
northern Michigan by Gleason (1924), and in Indiana by Esten (1932).
In Ohio the beech-maple association is emphasized by Sampson (1927) as
one of the four primary plant communities in the state on the basis of area
covered. Sears (1925), attempting to reconstruct the picture of the natural
vegetation of Ohio before the advent of the white man noted that beech,
unmixed with oak or ash, was practically limited to the glaciated region of
the state. References to the occurrence of both beech and sugar maple
throughout their range will be found in the Naturalists’ Guide to the
Americas, edited by Shelford (1926).

Hemlock is recognized as a frequent constituent of the beech-maple as-
sociation (Gleason 1924, Weaver and Clements 1929). The hemlock for-
est has been described by Lutz (1930) and the environmental requirements
of hemlock studied by Moore, Richards, Gleason and Stout (1924).

The animal content of the forest, the relationships between plants and
animals, and the consideration of the biotic community as such have not
thus far been given the consideration accorded to the plant constituents of
the community. Important contributions have been made in this country
by Adams (1906), Shelford (1913), and Chapman (1931); and in Eng-
land by Elton (1927, 1930). The mammals of a beech-maple forest in
Michigan have been listed by Dice (1920), and an ecological survey of Isle
Royale conducted by Adams (1909) included a study of animals found there.

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 5

The insect life of an elm-maple forest in Illinois has been studied in detail
by Weese (1924), and much the same thing has been accomplished by
Blake (1926), working on Mount Katahdin in Maine. A study of the biotic
communities of the aspen parklands of central Canada was made by Bird
(1930). Shelford and Olsen (1935) have pointed out the relation which
animals may have to plant communities as indicators, and maintain that
plants and animals are inseparably united in the structure of any community.
Much painstaking labor has been devoted to the study of various phases
of animal ecology by numerous workers, but there is little in the literature
that treats of forest communities as biotic units.

DESCRIPTION OF AREA STUDIED

LOCATION AND PHYSIOGRAPHY

To the northeast of Cleveland, Ohio, and some 16 miles from the city
limits, lies the tract of land known as the North Chagrin Reservation of
the Cleveland metropolitan park system. It contains 1,201 acres (486.04
hectares), and is roughly rectangular in shape, being approximately a mile
and a half (2.41 kilometers) square (Board of Park Commissioners, Report
1932-1933). It lies between parallels 41° 33’ and 41° 35’ north latitude.

The reservation occupies a position at the extreme edge of Appalachian
Plateau, as the Portage Escarpment which limits the plateau in this region
is represented by the high bluffs of the Chagrin River valley which are a part
of the area. The location is well within the boundaries of the advance of
the ice sheets of Pleistocene times (Cushing, Leverett, and Van Horn 1931).
Lake Erie is distant about 5 miles (8.04 kilometers) in a direct line toward
the northwest.

Within the reservation the land slopes gently toward the east for about
a mile (1.6 kilometers), where it drops steeply almost to the level of the river.
This bluff which marks the border of the valley is deeply and frequently cut
by short gullies and ravines only a few of which are extensive enough to
carry water all the year. The United States topographical survey map
(Mentor Quadrangle) shows the difference in level between the western
margin of the reservation and the river to be 220 feet (67.05 meters).

The particular area chosen for this study lies along the southern boundary
of the North Chagrin Reservation. It is approximately 65 acres (26.3
hectares) in extent, is entirely wooded, and includes some of the character-
istic gullies, ravines, and bluffs of the locality. It does not include any of
the river bottom or lower lands. It slopes toward the northeast from 860
feet (262.12 meters) to 760 feet (231.64 meters) above sea level. In out-
line it is somewhat irregular, because of the nature of the ground, except
at its southern and western limits. It is traversed by several foot-trails and

6 THE CLEVELAND MusEuM oF NATURAL History Pa

c---
pr7e----

LINE —
(243.8 ME

t
i
t
RIVER

=——_ =

SCALE = 1 INCH’=2250' FL
1 CM. #0202 ie

Fig. 1. Map of North Chagrin Reservation showing location of area under study.

bridle-paths which greatly facilitate quiet and easy access to all of its parts.
Reference to Figure 1 will give an idea of the topography of the area and
of its relation to the entire North Chagrin Reservation. It should be noted
that the reservation is not an isolated piece of forest land. While to the west
the country is occupied by farms, the adjoining land to the north and south
and across the river to the east is largely of the same character as that of
the reservation itself.

GEOLOGY AND SOIL

The geological formation immediately underlying the surface soils is that
known as the Cleveland Shale. This is a sedimentary rock apparently
composed of consolidated black mud (Cushing, Leverett, and Van Horn
1931). Upon this bed-rock of shale a layer of soil of glacial origin known
as the Volusia Clay Loam has been deposited. Coffey and Rice (1912),
describing this soil, say: “As a general rule, both soil and subsoil are markedly

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 7

deficient in lime carbonate, and will redden litmus paper quickly. The
Volusia series is derived from glacial deposits of shale and sandstone mate-
rial which covers the northeastern section of Ohio.’ The Volusia Clay
Loam is a poorly drained soil, and not among the more productive soils of
the State. The presence of beech trees is said to be characteristic of the
Volusia series. Over the clay loam above described there has been built
up a layer of humus of a loose and spongy character from 1 to 4 inches
(2.54 to 10.16 cm.) in depth. The clay soil beneath the humus is not more
than from 4'to 9 inches (10.16 to 22.86 cm.) deep, but it is friable and
porous as compared with the subsoil, which is of dense yellow clay.

DRAINAGE

Because of the heavy quality of the underlying sub-soil, standing water,
in hollows, after rains or melting snows, is of common occurrence on the
more level parts of the area. Depressions left by the uprooting of large
trees will sometimes contain water most of the year if precipitation is fairly
regular. In winter and spring the woods of the higher or more westerly
part of the area are always wet. Aside from such water as may collect in
depressions or pockets, the run-off of excess water is rapid. Within the
area there are no constant streams, the waterways with one exception being
short and the gradient steep. One waterway, having its collecting basin in
the open fields outside the area, and traversing its higher portion in more
leisurely fashion, does not become entirely dry except after periods of pro-
longed drought.

CHINE

The close proximity of Lake Erie may be considered as a factor modify-
ing to some extent the climate of the region. In general, as has often been
pointed out, temperatures do not rise so high nor fall so low near the lake
as they do farther inland. The lake also is often responsible for a condition
of cloudiness that cuts down very appreciably the amount of available sun-
shine (Moseley 1897).

In order to secure positive information as to the factors of temperature,
humidity, and precipitation within the area, four stations were established
and their operation begun on January 1, 1932. Two of these stations, desig-
nated as “A” and “B,” were located in beech maple environment. The other
two, designated as “C” and “D,” were located in beech-hemlock environ-
ment. At Station A a hygrothermograph giving continuous records of tem-
perature and relative humidity was installed in a wooden shelter resting
on the ground. A rain gauge, by means of which precipitation over a circu-
lar area 3 inches (7.62 cm.) in diameter may be measured in hundredths of
an inch, was located here. At Stations B, C, and D, maximum and mini-
mum thermometers and rain gauges similar to that at Station A were in-

8 THE CLEVELAND Museum oF NATURAL History ace ea

stalled. The thermometers were secured to the north sides of large trees
about 5 feet (1.52 meters) from the ground, and the rain gauges located be-
neath the same trees from 6 to 10 feet (1.82 to 3.04 meters) from their
bases. Readings from all instruments were taken with regularity weekly,
and the operation of the hygrothermograph regularly checked as to tem-
perature with a tested thermometer, and as to relative humidity with a cog
psychrometer. The thermometers were compared at different temperatures,
and their readings found to be in agreement. Their accuracy was also
checked with a standard thermometer.

TEMPERATURE

Figure 2 shows the mean temperature by weeks, on the basis of hourly
readings, at Station A for the year 1932. To this has been added the records
of mean temperature for the same weeks as recorded by the Cleveland
Weather Bureau, and also the curve of normal temperature for Cleveland.
It will be noted that the means for Cleveland follow closely the fluctuations
recorded at North Chagrin. It is thus possible to construct a table of cor-
rections for the Cleveland figures which may be used for further tempera-
ture studies at North Chagrin. Table 1 shows these corrections. It is ap-
parent that the appearance of the leaves on the trees, and the development
of a full and dense cover of foliage, which takes place from the middle of
May to the middle of June is a definite factor in modifying temperatures in

LCS
CCR AA
COAG le oe

LF |

Ai | al th ene ph
Ma
Uae

Fic. 2. Mean temperature by weeks on the basis of hourly readings at station
“A” 1932, with mean temperature recorded for the same period by the Cleveland
Weather Bureau. Curve of normal temperature for Cleveland.

July, 1936 A BrEEecH-MAPLE CLIMAX COMMUNITY 9

See
ea a

80,

60 I i
Sar sane nee
sigh aa e:
1993 -DOTTE a 0

Fic. oy Weekly mean temperature at North ae me en and 1935, from
Cleveland Weather Bureau figures corrected in accordance with table 1.

the beech-maple forest. The Cleveland station of the U. S. Weather Bu-
reau gives 200 days as the length of the growing season in this locality.

By the use of the correction figures (Table 1) the mean weekly tempera-
tures at North Chagrin for the years 1933, 1934, and 1935 are shown not to
be greatly different from those of 1932 (Fig. 3). Differences in temperatures
recorded at the 4 stations were not great enough to be considered especially
significant. After the middle of May when the leaves were on the trees
there was little or no difference in the minima and but slight difference in
TaBLE 1. Differences between temperatures at Cleveland and at North Chagrin, 1932,

averaged for each month, and figures used for correcting Cleveland temperature records
to show conditions at North Chagrin. (1° F.=0.56° C.).

Weekly Mean Weekly Maximum Weekly Minimum
Month |)
Actual Correction Actual Correction Actual Correction

Difference Figure Difference Figure Difference Figure

ianuary........ —2°F —2° —2°F —3° —1°F —1°
February....... —3 —2 —5 —3 —2 —1
Mawel... 1... —2 —2 —4 —3 —t 4+
PAPA E sie a Sw cso —1 —2 0 —3 —3 —t
257 ae —2 —2 —1 —3 —t —t
meee ka. s —4 —4 —3 —3 —6 —o
PRGA shc Ge kie's. 0 es —5 —5 —5 —5 —t —o
ENTS Cl —5 —5 —6 —6 —6 —6
September...... —4 -—-+ —6 —6 ae —o
Wetober.. .... 6. —3 —3 —t —t —3 —3
November...... —2 —2 —3 —t —3 —3

10 THE CLEVELAND Museum oF NATURAL History Sees —

the maxima of all stations, 4° being the greatest divergence recorded. It
may be said, then, that temperature in the area at five feet above the ground
is practically uniform throughout, whether in beech-maple or in beech-
hemlock environment, except as affected in minor ways by exposure or
shelter.

RELATIVE HUMIDITY

Figure 4 shows the weekly means of the records of relative humidity
on the basis of hourly readings at Station A for the year 1932. The mean
relative humidity for the year was 83.3 per cent. When a comparison by
weeks is made it appears that with few exceptions the amount of relative
humidity was generally between 75 and 90 per cent. Records of many hours
showed frequent periods of 100 per cent. A notable exception occurred
during the latter part of April, a time of low precipitation, when great ex-
tremes of humidity were recorded daily, the record fluctuating between 16
and 100 per cent.

TTTITITI TT
WU a PA
Se

JUN ILY

Whe Sas Mean relative humidity by weeks on the basis of hourly readings, station

90;

PRECIPITATION

Records of amount of precipitation were obtained weekly during 1932
at all 4 stations. The individual instruments at times varied somewhat as
to amount of water collected, but in the long run they approximated fairly
closely (Table 2).

TABLE 2. Total precipitation at 4 stations: January 1 to December 31, 1932.
Station A —beech-maple — 31.70 inches (80.52 cm.)
Station B —beech-maple — 32.41 inches (83.32 cm.)
Station C — beech-hemlock — 29.23 inches (74.24 cm.)
Station D — beech-hemlock — 29.11 inches (73.94 cm.)

If the records of the two stations in beech-maple environment be aver-
aged, and compared with the average of the two stations in beech-hemlock
environment, it appears that the hemlocks received 2.88 inches (7.31 cm.)
less water about their roots during the year than did the deciduous trees.

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 11

Since so little variation in precipitation was shown between the stations,
the taking of further precipitation records was continued at Station B only.
The records at this station by months for the 4 years of this study is shown
in Figure 5, use being made of the diagrammatic method first introduced by
Transeau in 1931 (Cain 1932). <A study of these precipitation patterns
discloses the fact that in 1932, during the growing season and immediately
before, precipitation was very light, and that again in 1933 conditions during
the growing season were marked by a deficiency of moisture. In fact, such
rain as did fall in the summer of 1933 was concentrated in a few downpours
which, because of the rapid run-off and speedy evaporation, was very in-
effective, hardly reaching the soil beneath the forest litter to any great extent.

The year 1934, however, proved to be one in which precipitation, though
deficient in May, was above normal in the summer and autumn, although
this was the year of the great drought in other parts of the country. Because
this record seems unusual it is fortunate that records of precipitation are
available for the summer and early autumn of this year from the farm of
Mr. B. P. Bole at Kirtland Hills, about 6 miles (9.65 kilometers) to the
northeast, as a check upon the North Chagrin records. As a further check
2 additional rain gauges were operated in the spring of 1935 on either side
of the North Chagrin instrument and about 10 feet (3 meters) away from
it. Over a period of 4 weeks all three instruments were found to be in
accord. For purposes of comparison the Bole farm records and those of
the Cleveland Weather Bureau for 1934, as well as the normal precipitation
for Cleveland, are included in Figure 5. As a matter of general observation
it may be said that weather conditions at Cleveland and at North Chagrin are
frequently not the same.

WIND

That the forest is responsible in many ways for its own micro-climate
is strikingly shown in the way in which the movement of wind within its
borders is modified by the presence of trees and other plants both in summer
and in winter.

Toward the west the edge of the forest under study is bordered by an
open field, and so presents an unbroken front to the full force of the wind
from this direction. At this point, readings with an anemometer of the
“windmill” type, measuring the velocity of the wind in feet, were taken
over periods of 5 minutes each, first outside the forest, to measure the
force of the wind at this point, and at each succeeding 100 feet (30.48
meters) within the forest, following the direction of the wind, until a
point 1,000 feet (304.8 meters) from the edge was reached. The velocity
of the wind at the outside was then again measured, and the average of
this, and the first outside measurement taken as the velocity of the wind
during the hour or more consumed in taking all of the records. Six such

12 THE CLEVELAND Museum oF NaTurRAL History = i

PRECIPITATION

TOTAL 32.41 JAN STATION “B” TOTAL 26.87

3.86 IN

APL

RADIUS OF
CIRCLE = 3 INCHES
(7.62 Cm) OF WATER

A 2 Gene eid FSS

Fic. 5. Precipitation by months, station “B,” 1932, 1933, 1934, and 1935, with Bole
Farm records and Cleveland records for 1934, and normal for Cleveland.

complete records were obtained at various times and under various conditions
when the trees were bare of foliage, and five complete records when the trees
were in full leaf. Table 3 shows the amount of decrease in velocity after
reaching the 800-foot mark. Records are reduced to feet per minute.
Reduced to percentages of decreased velocity from the forest edge in-
ward, the results of these records are given in Figure 6. The records from
the 700-foot point and further were usually of light and shifting air cur-

July, 1936 A BrEEcH-MAPLE CLIMAX COMMUNITY '

TABLE 3. Effect of forest on wind velocity.
(records in feet per minute)

Trees Without Leaves Trees With Leaves
Average velocity|Average velocity Average velocity|Average velocity
Record in open 800-1000 ft. Record in open 800-1000 ft.
Le 862 f.p.m. 161 f.p.m i 763 f.p.m. 47 f.p.m
2. 826 68 Di 573 22
3: 671 111 3 481 D4
4, 615 172 4, 343 23
5. 495 175 5. 284 64
6. 339 159

Note: 100 feet = 30.48 meters.

rents. Several readings taken further within the forest showed essentially
the same conditions. Comparing summer and winter conditions it appears
that there is from six to seven times more air in motion near the ground in
winter than in summer.

SUNSHINE

Figure 7 shows the possible number of hours of sunshine by months
for Cleveland, and also the actual number of hours of sunshine for the year
1932. For purposes of comparison the curve of the normal number of
hours of sunshine for Cleveland is included. It is apparent that the total
amount of cloudiness during the year is very considerable. Even though
there were actually more hours of sunshine than normal in 1932 for 8
months out of 12, the actual number of hours of sunshine for the year were
only 56 per cent of the possible number—the normal being 52 per cent.
During the winter months, December, January, and February, the normal
proportion of sunshine sinks to 24, 29, and 35 per cent of the possible num-
ber of hours.

While no measurements of light intensities were made, it should be noted
that the beech-maple-hemlock forest is a dark forest in summer. One of
the first things of which one becomes conscious upon entering this forest
on a bright summer day, is of the great decrease of light intensity. The
eyes need to become adjusted to this condition before much can be seen.
The writer has frequently made exposures of 15 seconds duration on photo-
graphic film in order to get good pictures within the forest on days when the
summer sun was shining brightly outside. Using the same aperture, lens,
and film in the open on such a day would have necessitated an exposure of
one-fiftieth of a second. Although this is by no means an exact measure-
ment, it does indicate that light within the forest is one-seven-hundred-and-
fiftieth as effective on photographic film in midsummer as it is outside the
forest at the same time and otherwise under the same conditions.

14 THE CLEVELAND MusEeuM oF NATURAL HIstToryY goes

PER CENT
OF DECREASE

Re a a
(CLEC
SiC a
Ne
NC a
CNC EN

FEET-100 200 300 400 500 600 700 800 900 1000
NOTE :- 100 FEET = 30.4 METERS

Fic. 6. Decrease in velocity of wind from forest edge inward in summer (heavy
line) and winter (dotted line).

EVAPORATION RATE

During the summer of 1934 an attempt was made to secure data on the
rate of evaporation of moisture, both in the forest, and in the open just
outside the woods to the west. For this purpose standardized Livingston
porous clay bulb atmometers were used, evaporating distilled water only.
Although a group of three instruments were run in the woods, so that read-
ings might be averaged, continual interference with the bulbs by gray squir-
rels, and the growth of protococcus on the bulbs at times, reduced the num-
ber of available instruments often to two, and sometimes to one. There
were also two short periods when all instruments in the woods were out of

July, 1936 A BreecuH-MapLe CLIMAX COMMUNITY 15

HOURS PER
MONTH

Ne
pny | perl | NO
See SE

Fic. 7. Possible and actual number of hours of sunshine for Cleveland
in 1932, and normal for Cleveland.

commission due to these causes. The one instrument in the open field ran
continuously without interruption from August 1 to October 15 when the
bulb was shattered by freezing. To get some idea of winter conditions,
readings were taken twice over short periods in November and January when
the temperature was above freezing. Table 4 gives the data obtained from
these instruments.

The rate of evaporation is apparently affected greatly by various atmos-
pheric conditions. Wind greatly increases it. Precipitation in summer and
freezing in winter slows it up. High temperature with dryness is conducive
to a high evaporation rate. The effect of the forest in reducing the rate of
evaporation within its borders, as compared with conditions in the open,
is striking, showing an average difference of 55.2 per cent in summer when
the leaves are on the trees, and of 38 per cent in winter when the forest is
more exposed to the influence of wind.

SUMMARY OF CLIMATIC DATA

From the data gathered over the four-year period of this study, the
climate of the area may be summarized by saying that temperatures are
not extreme, varying from -13° F. (-25° C.) in winter to 96° F (35.5° C.)

16 THE CLEVELAND MusEuUM OF NATURAL HIsToRY ait ae

TABLE 4, Evaporation rates at approximately 12 inches (0.304 m.) above ground.

Open field. Beech-maple.
Rate of Rate of Per cent of
Date—/934 evaporation in evaporation in decrease from Weather
cc. per hour cc. per hour open to forest conditions
June 1- 4.. De fee 0.835 UY very dry
Sica Pe OL Ne aE 0.713 fies very dry
Si ane cesta 0.524 eee wet
Bo = 12s Ul ee 0.402 See very wet
July PAS fs aa 0.404 SS very wet
oe (oad Ry Se 0.271 aye very wet
August 1- 6.. 0.940 0.350 62.8 very wet
6-13.. 0.807 0.285 64.7 very wet
13 = 22) 0.740 No record ee very wet
pap iy 0.760 0.270 64.5 very wet
Dies aes 0.610 0.255 58.2 wet
September 1-10.. 0.497 0.275 44.7 wet
10-17.. 0.287 0.152 47.1 wet
17 — 24.. 0.520 0.231 35.6 wet
24- 1.. 0.428 0223 47.9 wet
October bi Oey 0.619 0.180 71.0 very wet
8-15.. 0.481 0.307 36.2 (leaves falling) —dry
na thangs = — 26.. L377, 0.757 33.5 (heavy wind) —dry
193.
January 6=\7.. 0.402 0.231 42.6 (ground frozen)

Average evaporation in forest, June 1 to October 15, — 0.355 cc. per hour per instrument.

in summer; that it may be subject to unseasonable weather, but that for the
most part temperatures are within closer limits; that relative humidity is
high, for most of the time ranging between 75 and 90 per cent; that precip-
itation is rather uniform throughout the year, averaging 2.84 inches (7.21
cm.) per month, or 31.62 inches (80.31 cm.) per year for the period of
this study; that for 52 per cent of the time when sunshine is possible the
sky is overcast; that the force of the wind is ordinarily so tempered by
the trunks and branches of the trees in winter, and the addition of their
foliage mass in summer, as to make wind disturbances rare throughout its
lower levels; that the rate of evaporation is reduced within the forest from
47.1 to 64.7 per cent in summer to from 33 to 42.6 per cent in winter, as
compared with the open field at its western edge.

HISTORY, OF THE AREA STUDIED

The former Indian occupation of this region is well attested by the col-
lections of flint and stone implements assembled over a period of years by
Mr. Ray Parker and Mr. Carl Scheuring whose farms are located close to
the area on the southwest. The forest of the area, says Mr. A. C. Keesler,
who has lived all his life nearby, has always been a beech woods. The
large stumps, well advanced in decay, seen occasionally in the woods, he
says represent a cutting made when he was a boy of about 14 (1871), when
some large oak, hickory and tulip trees were taken out for lumber. Ap-

July, 1936 A BrEEecH-MAPLE CLIMAX COMMUNITY 17

parently the particular portion of the area in which our interest centers
has suffered little from major disturbances for a long time. There is no
evidence of serious fire, either in the place itself, or in the memories of
those who, like Mr. Keesler, have a long family tradition associated with
the place.

In 1925, 1926, and 1927, the Cleveland Metropolitan Park Board ac-
quired practically all of the 1,201 acres (486.04 hectares) now known as
the North Chagrin Reservation, and containing the area under study. Since
that time all wild life within the boundaries of the reservation, including
both plants and animals, has been under complete protection, no hunting,
or other disturbance of natural conditions having been allowed. The pol-
icy of the Park Board has been that of conserving natural conditions as far
as possible. Picnic grounds and playgrounds are located outside the forested
areas. Foot-trails give access to the forest, but there has as yet been little
straying from the trails on the part of visitors. No picnic parties are al-
lowed within the woods. One bridle-path crosses the area, and another
skirts its western edge. Two uniformed guards regularly patrol the entire
reservation to see that park regulations are respected.

CHARACTER OF THE ROREST

PLANT CONSTITUTION

TREES

In 1932 the writer had recourse to the familiar quadrat method of de-
termining the abundance and distribution of trees and shrubs throughout
the area, but as increasing familiarity with the forest was gained it be-
came apparent that the results obtained by the quadrat method were far
from satisfactory, and this method was abandoned. Instead, during the
winters of 1933-34 and 1934-35, all of the larger trees of the area were
measured, and their approximate location charted on individual maps for
each species. Measurements were made by tape giving the circumference
breast high in inches, and only trees of 30 inches (76.2 cm.) or over in
circumference, or slightly over 9.5 inches (24.13 cm.) in diameter, were
thus measured and their location charted. Later, a count of all trees of each
species was made, section by section, but without the use of quadrats or
other measured areas. In this count an effort was made to include all trees
down to the 3.5 inch (8.9 cm.) diameter class, the size being judged by eye.
While the figures thus obtained are doubtless subject to some error the
writer believes them to be substantially in accord with the facts.

On the basis of these counts and maps (Figs. 9 and 10) it appears that
there exist 4 major vegetational divisions within the area (Fig. 8) which
may be designated as follows:

18 THE CLEVELAND Museum oF NATURAL HIstTory Bo i

(1) The spurs of the eastern edge of the area. Here occurs a forest
mictium including beech, hemlock, red oak, and chestnut, as dominants, to-
gether with a relatively large proportion of other species. Chestnut is as-
signed its position on the basis of large standing trees, though at the present
time none are living. It was so recently an important member of this com-

(
hi,

= <a
i]
1
[|

/SPURS( MAND RAVINES
FLOODPLAIN
EXTENSIONS:

FOREST M\c\TIUM- ~

7
/

INTERIOR FOREST

Fic. 8. Major vegetational divisions of the area under study.

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 19

munity that it seems desirable here and elsewhere in this study to recognize

its former significance.
(2) The ravines between the spurs. In the deeper ravines an excess of

moisture is always present. Here herbaceous vegetation prolongs its sea-

SUGAR MAPLE .. RED MAPLE

BOR SEG
eeerte e0,°

e
e%%e e @, e
e e
oe” 18% ee? 982?

N AMERICAN ELM
f +SLIPPERY

rTP CWHITE. ASH
TULIP STUMPS *BLACK AS

Fic. 9. Distribution of tree species throughout the area under study.

20 THE CLEVELAND MusEuUM OF NATURAL HIstTory = Pub

son and grows to larger size than upon the upland. Only here can ferns
be said to be well developed. Trees in the ravines often represent bottom-
land species which have thus extended the flood-plain forest into the area,
bringing in some species which otherwise seem out of place. Beech is

+ SASSAFRAS
¢ BASSWOOD

eWILD BLACK bay ans

+ AMERICAN HORNBEAM. » FLOWERING DOGWOOD
+SHADBUSH

Fic. 10. Distribution of tree species throughout the area under study.

July, 1936 A Breeco-Mapite CLIMAX COMMUNITY 21

absent from the ravines but sugar maple and tulip are present, and in cer-
tain places hemlock is found in the ravines. Thus the ravines might be
considered as the beginning of a transition stage toward swamp forest or
flood-plain conditions.

(3) The western forest edge, and particularly its southwest corner.
Here, with the exception of some large American elms, the forest is younger
than elsewhere, and its character leads one to believe that a portion of it
may have served at one time as a “wood-lot” in which only the elms were
left undisturbed. The southwest corner has considerable standing water
in it during most of the year which accounts for the numbers of American
elm, basswood, and red maple here, and the presence of black ash; suggest-
ing the elm-black ash-red maple association described by Sampson (1930)
as characteristic of the swamp forest of northeastern Ohio.

(4) The interior forest. This includes the larger part of the area under
study. The land here is relatively level, and the forest is quite uniformly
beech and sugar maple in varying proportions, including a few other asso-
ciated species as secondary or incidental dominants.

Table 5 shows the abundance and distribution of tree species throughout
the four habitats above described. Figure 11, following the method used
by Sampson (1930), reduces Table 5 to graphic form. Scientific names in
this, and in the following lists of vascular plants, are as given in Gray’s
Manual of Botany, seventh edition (1908).

Taking the forest as a whole it should be noted that beech composes 51
per cent of it, sugar maple 26.5, red maple 7.2, and hemlock 6.6 per cent.
These four species together thus make up 91.4 per cent of the forest. In-
asmuch as chestnut has already ceased to be a factor in the community, and,
as will be shown later, hemlock and red oak are tending toward exclusion,
and tulip and white ash are here secondary succession trees, it appears that
the species of greatest importance in this forest are beech, sugar maple,
and red maple.

| SUBDOMINANT GREEN PLANTS

In this group belong the shrubs, the herbs, the ferns, the climbers, twiners
and trailers, and other low-growing plants. As the shrub layer society is
very poorly and irregularly developed throughout the entire area, significant
differences in the distribution of the plants of this list (Table 6) are largely
as between beech-maple and beech-hemlock environments, and their oc-
currence in either or both of these associations is noted. The order of
listing, except in the case of the uncommon to rare species, or unless other-
wise noted, is in the order of their abundance.

Spicebush is the most abundant shrub in the area, but it is concentrated
largely in two rather moist situations. Maple-leaved viburnum is better
distributed than spicebush, but occurs only sparingly. Red-berried elder is

22. THE CLEVELAND MusEUM oF NATURAL HISTORY oe Pup.

TABLE 5. Species, abundance, and distribution of trees of 3.5 inches in diameter and over.
IICCCCQqQqQuQqQquoQooaooaouaoauqquu Sess Ee TxTTTTTT—

Beech- Transition toward
hemlock- swamp forest
Beech- oak-
Species maple- chestnut
association | mictium In Swampy
ravines area
zi¢lelele2|¢ |) 2

Beech—Fagus grandifolia Ehrh.................-6- 19205226) 9/O7|\"43-0lb eee ee 87| 28.4| 2714] 47.2
Sugar Maple—Acer saccharum Marsh.............- 1193] 32.7) 124) 7.5 19} 13.0 79| 25.6) 1415] 24.6
Red Maple—Acer rubrum Li... eee eee eee ees 227) SGe2 11S sd 10} 7.0} 31] 10.0) 381] 6.6
Hemlock—Tsuga canadensts (L.) Carr............-. 36|. 1.0}, 242)):14-91) 72) 49-0). sl eee 350) 6.1
Chestnut—Castanea dentata (Marsh.) Borkh......... 36> D0) 23551459 ee esl eee | eee eee 271} 4.7
Tulip—Liriodendron tulipifera L.... 2... eee eee eee 110} 3.0 14/ 0.9 6| 4.0 2) 1:7) (82) 2-3
Red Oak—Quercus rubra Tan ...ie si sccts vip ce tajeleie nine ve as 8} 0.2} 78) 4.8 5) 3.4 3) 10) Ser a6
White Ash—Fraxinus americana L.............00: 72) Kin O37 Ses anlar 7 AST" 29a eS sy Ua Wag k
American Elm—Ulmus americana L................ HS); 1 DeSiseesclevase 7| 4.7| 24) 8.0} 49) 0.9
Hop Hornbeam—Ostrya virginiana (Mill.) K. Koch. . 18} 0.5 P21 WM Be tle bee Aes 6| 2.0; 45) 0.8
Basswood—Tilia americana L.... 2... .e eee cece eee TAWA OA IB Ses ae 6] 4.01" 25) ase2 38} 0.7
Shagbark Hickory—Carya ovata (Mill.) K. Koch..... 20} 0.5 Ae iO) 2st re eal eoe cies Ti) (Bes 31} 0.6
Tupelo—Wyssa syloatica Marsh..........020-00 0. oe St OLR QE) D2 cic aallers ent] eee ee 26} 0.4
Cucumber—Magnolia acuminata L...............-. Ai \OR2 BRS Wie Cel rere Rel Pan ols or 25) 0.4
White Oak—Quercus alba Lu... .. 2 cece cece eee fA) We? MST WORE Seealliianoc 1) 3023 24| 0.4
Sassafras—Sassafras varritfolium (Salisb.) Ktze...... Si) Ord 15) | O95 tec eee ee 18} 0.3
American Hornbeam—Carpinus caroliniana Walt.... te ORs Ls 2050) ayaaleeeee 6| 2.0 18} 0.3
Flowering Dogwood—Cornus florida L.............. 1) O20 10)}) 0.6). 6.5 3) tske alee pee 11) 0.2
Wild Black Cherry—Prunus serotina Ehrh.......... 1} 0.0 5p Oe2 3). 2-0 eer eee 9} 0.2
Slippery lm—Ul mus fuloa Machx.)..: 22 ah. she ia|e lee che we a el. oe ee] 4 ste ele 6} 4.0) 2ccsieeee 6| 0.1
Black: Aish——Feraxinws) nigra) Niarses s oi<is. 55) 5 occa -ate Oe fol azote teh sere] eevee Giller esecaysi] crete aicl one care 6} 2.0 6| 0.1
Black Walnut—Juglans nigra L.. 2... cece cee cet lowe cslocecs 2) Ont Z| Liane cele 4 0.1
Pignut—Carya glabra (Mill.) Spach................|.-20-]e0--- AY 0.2) nicacl] uaceale aaee cee 4! 0.1
Bitternut—Carya cordiformis (Wang.) K. Koch...... DS (OO ieatianeat 2) V4lcoealeeeee 3
Shadbush—Amelanchter canadensis (L.) Medic.......|.....|..--- 3), Os2) 5. cates he eel 3
Butternut—/uglansicrnerea i arncte aeceiee ris) xcraet et alN ake ae ei] (os elke =| eueieyekal| (eet esens Alms Wee Ne ec lle sos - 2|7 0.2
Black Birch——Betulavlenta ls. cncls a cle stolen avia erexeletein Nlevstele si|leiereiere 2 OAs ite alls cseeic'| Seine Home 2
Scarlet Oak—Quercus coccinea Muench............|-..-.|----- DP] O20 |e aeale.cas aoe See 1

aotals tiga tee ee citve sieve ate ceauvat cary 865462. 1GS8le2.5- 1475 eles S06\en eee 5745/100.0

commonly found as a subseral plant where the soil has been disturbed. In
most cases the shrubs give the impression of struggling under severe limita-
tions. Their development is usually poor, and they fruit sparingly except
in open situations.

In the beech-maple association the herbaceous plants grow luxuriantly,
and produce annually a tremendous crop of seeds, fruits, and other food
reserves stored in corms, tubers, root-stocks, and other like structures.
Spring beauty, spring cress, cut-leaved dentaria, and yellow adder’s tongue
occur in great numbers on the higher land where there is usually a surplus
of standing water in April and May. In certain places the forest floor may
aptly be said to be “carpeted” with the blooms of these species. The two
trilliums are very abundant in the mid-portion of the area, and grow to
large size in the ravines. Dutchman’s breeches is common on the higher
ground, while squirrel corn seems to prefer the sides of the ravines. Four

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 23

TRANSITION BEECH-HEMLOCK-
SPECIES | TOWARD BEECH -MAPLE wip ALT]
SWAMP-FORESTA ae AT sul CLT UM

WHITE ASH |
AMER. ELM F
1H. HORNBEAM
SHAGBARK
BASSWOOD
TUPELO
|CUCUMBER
WHITE OAK
| SASSAFRAS
A. HORNBEAM
F. DOGWOOD

BLACK ASH
BL.WALNUT
BUTTERNUT
BITTERNUT
|PIGNUT

Fic. 11. Distribution and abundance of tree species showing relation to beech-
maple association and contiguous forest types.

24 THE CLEVELAND MusEuM oF NATURAL History oa Pate

TABLE 6. Subdominant green plants.

Beech- | Beech-
maple | hemlock

1. SHRUBs:
Spicebush—Benzoin aestivale (L.) Nees... 2.0.02. cece cece eee eee
Maple-leaved Viburnum—Viburnum acerifolium L...............
Red-berried Elder—Sambucus racemosa Li... 0... eee
Highbush Blackberry—Rudbus allegheniensis Porter...............
Prickly *Gooseberty— Rives cynosbati Ge oe eee
Purple-flowering Raspberry—Rudbus odoratus L.... 2... eee
Witch Hazel-—Hamamelis virgintana Van i acie iis nica eames eieieeiee
Choke 'Cherry—Pranus virginiana V1) 2h. aie See ew eee
Common Elder—Sambucus canadensis Li... oe ce eee
Fly Honeysuckle—Lonicera canadensis Marsh. .............2.45.
Bush Honeysuckle—Diervilla lonicera Mill...............000 ce eee
Low Sweet Blueberry—Vaccinium pennsylvanicum Lam...........
Leatherwood Dirca palustris Ti io). OG sot bs wee elas a

*eexeteetexeteetsR &
*

%* %& &

2. CLIMBERS, TWINERS, AND TRAILERS:
Northern Fox! Grape—V its Vabrasea Wa.) eo. Sale cee - dee ee
Trailing Euonymus—Evonymus obovatus Nutt.............00006.
Virginia Creeper—Psedera quinquefolia (L.) Greene..............
Potson! lvy—-Rads toxicodendron Vs) eo. 5 kl ee ee oo oe
Green Briet—Swtlan rotundifolia Vi... ce ce a es te ek Oe eRe
Carrion Hlower—Satlex herbaced (a... 0 oe ae need cee ee wae
Bittersweet——Celsstrus scandens Na. .k ak zeae les weds 6 eee Roe

* # ee He He ¥

3. Herss AND Low Suruspsy Pants:

a. Abundant species (somewhat in the order of their flowering)
Hepatica—-Hepatica acutiloba DC.) is vs nisba cs sce ae ee
Spring Beauty—Claytonia virginica Li... 6 cc ees
Yellow Adder’s Tongue—Erythronium americanum Ker........
Round-leaved Violet—Viola rotundifolia Michx...............
Halberd-leaved Violet—Viola hastata Michx..................
Wake Robin=—9 rilium erectum Vn. 86 oe Les east 8c soln semen
Dutchman’s Breeches—Dicentra cucullaria (L.) Bernh.........
Cut-leaved Dentaria—Dentaria laciniata Muhl...............
Spring Cross—Cardamine bulbosa (Schreb.) BSP..............
Squirrel Corn—Dicentra canadensis (Goldie) Walp. . b A
Rue Anemone—Anemonella thalictroides (L.) Spach. . Rieu
Great White Trillium—Triliium grandiflorum (Michx.) Salisb. .
Wild Ginger—Asarum canadense Li... ce ce cee
Sweet Cicely—Osmorhiza claytoni (Michx.) Clarke............
Toothwort—Dentaria diphylla Michx..............000..0005:
Oakesia—Oakesia sessilifolia (L.) Wats... ......0.000c0eceees
Downy Yellow Violet—Viola pubescens Ait...........0ecceeee
Smooth Yellow Violet—Viola scabriuscula Schwein............
Canada Violet—Viola canaaensts Vasc vk oie os gk Ue Oe
Dwarf Ginsene—Panax trifolium Vic: joc os bo Powe ewe ee
Foam: Klower——Ttarclia cordifolia Wie oes eu ioe eee ee
Solomon’s Seal—Polygonatum biflorum (Walt.) Ell............
Canada Mayflower—Maianthemum canadense Desf............
Jack-in-the-Pulpit—Arisaema triphyllum (L.) Schott..........
May Apple—Podophyllum peltatum Li... oo. cc cence
False Spikenard—Smilicina racemosa (L.) Dest hav id ake Ae
Pale Jewelweed—Impatiens pallida Nutt.............0.005. A
Spotted Jewelweed—Impatiens biflora Walt............0.000-
Pokeweed—Phytolacca decandria Noe. «ac iis eiavcte wien sv slainjs «tye ake §

eee Hee HER HH HHRHE HE HH HH HH H HK

* %&& & &

b. Common SpeclEs:
Blue Cohosh—Caulophyllum thalictroides (L.) Michx..........
Large-flowered Bellwort—Uoularia grandiflora Sm............
Swamp Buttercup—Ranunculus septentrionalis Poir...........

July, 1936 A BrEEcH-MAPLE CLIMAX COMMUNITY 25

TABLE 6. Continued

Beech- Beech-

maple | hemlock

Yellow Rocket—Barbarea vulgaris R. Br... . 2... eee ee ic

Common Violet—Viola papilionacea Pursh...............005. -

Indian Cucumber—Medeola virginiana Li... . ee ee * sg
Wald Sarsaparilla— raha nudicaulis Lie... 6.6 cee cae wwn 6

Twisted Stalk—Streptopus amplexifolius (L.) DC............. ‘¢
Partridgeberry—Mitchella repens Li... ccc ce cence "
Weinée Baneberry——Aciaea loa (1..) Mull... 2 hl... alee

MaldhEthe Phiox-— Phlox divaricata We) ).). eels ce ole sels tae

Northern Bedstraw—Galium boreale Lu... 1... cece cee cee
Black Snakeroot—Cimicifuga racemosa (L.) Nutt.............
Wintergreen—Gaultheria procumbens Li... ccc cece
Rvchweed—Pilea pumila (L.) Gray... .. 0... cc ee cece eens sf

c. Uncommon To Rare SPECIEs:
Harbinger of Spring—Erigenia bulbosa (Michx.) Nutt......... *
Bloodroot—Sanguinaria canadensis Li... cece eee
rating Acbutus—-/ preaca repens Lin. 3s. ie ee eee hae:
Perfoliate Bellwort—Uvularia perfoliata L..... 1.0.0. cee
Early Meadow Rue—Thalictrum diotcum... 0...
Wood Anemone—Anemone quinquefolia L..... 0... ee ee
Wood Betony—Pedicularis canadensis L... 1... cece eee
Sweet White Violet—Viola blanda Willd..............0000005
Great-spurred Violet—Viola rostrata Pursh...............0....
Weed Sorrel-—Oxales corniculata Va. 0. siens bigs en een be en
iBicneaps Cap—Mitella diphylla Ve... es bas es oe oes bel
Golden Seal—Aydrastis canadensis Li... ccc cece eee
Virginia Waterleaf—AHydrophyllum virginianum L.............
Pink Lady’s Slipper—Cypropedium acaule Ait................
Apmmony——Aerimoria striata MichX..2).\. 6.6/0.6 cso oie eros oe
Monkey, Plower——Mimulus ringens Vo... 0. ce eee sa es
Round-leaved Orchid—Habenaria orbiculata (Pursh.)..........
eat eopelia— Lobelia siphilitica We... snes bee eas 3
NunidMbeek-—— Allium tricoccum Alt.) jes). bbe ce bee he es tee
(Ginsene—Panax quingucfolium Von. w tee bees onde te oe
imnetan Vobacco—Lovelia inflata Vo... o. sins sae ait dee cing ees oe
Cardinal Plower—Vlobelia cardinalis L.. 0.0 bec et ee
Nodding Pogonia—Pogonia trianthophora (Sw.) BSP..........
SPIKEN ANG ATANG TACCINOSE LA. Voie) Wiese eta ast aceewsss

ee FE EHH EH HEH HF

*eeekee Ee HH He H

4. Ferns:
Christmas Fern—Polystichum acrostichoides (Michx.) Schot........
Spinulose Wood Fern—Asplenium spinulosum intermedium

COS ALOM ren Ee eran eee ais ce ae cninre Wisse si bln in wave 2.
Silvery Spleenwort—Asplenium acrostichoides Sw.............---
New York Fern—Aspidium noveboracense (L.) Sw...............
Marginal Shield Fern—Aspidium marginale (L.) Sw..............
Rattlesnake Fern—Botrychium virginianum (L.) Sw...........55.
Broad Beech Fern—Phegopteris haxagonoptera (Michx) Fee........
Maidenhair Fern—Adiantum pedatum L.. 0... ee
Long Beech Fern—Phegopteris polypodioides Fee...............---
pensive, Metn—Onocled SCNSIDIES Lie. ca acc wks eae ws sees
Ternate Grape Fern—Botrychium ternatum intermedium D. C. Eaton
Interrupted Kern—Osmunda claytontana L....... 2... eee eee
Narrow-leaved Spleenwort—Asplenium angustifolium Michx.......

*aereeke ete ereuene*ee & ¥

(in
ravines)

Hay-scented Fern—Dicksonia punctilobula (Michx.) Gray.........

26 THE CLEVELAND MuseuM oF NATURAL History Soe

TABLE 6. Continued

Beech- Beech-
maple | hemlock

5. Mosses:
Amblystegiam ser pens (L.) 3.8.8. ee ee ee ae ee
Dhaiainm delicatuinm (2): Mitts Plo. e Aes ae eee
iy pnum haldanianum Gree’ 02 2). 550. Aa me ae eee
iy prune reptile Nix ed es, oS eee aerials Re ey cei Re
Punoria hygrometricia (:.) Sibths: 3.54. eee
Leucobryum elaucnm (E.,) Schimp... 70 Aojcin. A ee ee
Warum cuspidaturm (ia) Aeyss.) 0) R ei eae Sane ee
Dicraneiia heteronalia (L:) ‘Schimp:; ..,.\.5)s8 hoe ee eee
Catharines undulala (WSO eae ES eee
Fissidens taxsfolius (i) Hedwy oes h.40 so Pea Ris 2 ee

* *& # He ¥
*

+t & *&

6. MiscELLANEOUS:
Sedge—-Carex plantaginea Latins: iii. fats oe ee
Club Moss—Lycopodium lucidulum Michx..........0..0000 000. :
Lichen—Cladonia fimbriata (L.) Hoffm. Deutsch.................
Liverwort—Marchantia polymorpha (L.)... 0... cece cece aes
Alga—Mtcrospora amoena (Kitz.) Lagerh.................00005:
Alga—Protococcus sp. (on beech trunks) .............00.2.00000 *

* & %& *

species of yellow violets bloom abundantly. Hepatica grows in masses in
moist places along the water-courses and on the edges of the ravines. False
spikenard, solomon’s seal, and twisted stalk are quite generally distributed.
Wild ginger and May apple cover the ground with their characteristic leaves
in certain locations. Jack-in-the-pulpit and blue cohosh are well distributed.
The tiny dwarf ginseng, in its season, shows its small puff-balls of white
bloom throughout the forest. The evergreen leaves of foam flower are
common in the wetter places, and over the edges of the ravines. Those
curious plants, beech drops, and squaw root, are common, the former more
so than the latter; and the pale Indian pipe is found frequently. The late-
comers, white baneberry and black snake-root, are common. Jewelweed and
pokeweed grow luxuriantly in certain places.

In great contrast to this rich development of herbaceous growth beneath
the beeches and maples is the thinly spread ground cover beneath the hem-
locks. The common herbaceous plant of the beech-hemlock association is
the Canada mayflower. In certain locations it covers the ground, but it
is the only plant of which this can be said. In this environment partridge
berry and wintergreen appear frequently. Apart from these there is very
little. It is in this habitat that a few plants of pink lady’s slipper and trail-
ing arbutus occur.

This difference in herbaceous growth was studied in Indiana by Dauben-
mire (1930), who concluded that, of the factors studied (light, evaporation
rate, soil acidity, soil moisture), soil moisture conditions exerted the most
inhibitive influence on vegetational development under hemlock, while the

July, 1936 A BEECH-MAPLE CLIMAX COMMUNITY i.

greater acidity of the surface soil is probably a contributing factor in the
inhibition of forest floor herbs.

In no place in the area do ferns grow in abundance. Small societies
of New York fern occur sparingly on the higher land and on some of the
spurs. Christmas fern, marginal shield fern, and spinulose wood fern are
all well distributed as individual plants, reaching their best development
along the edges of the gullies and ravines. Rattlesnake fern is well dis-
tributed on the higher land. Other ferns on the list occur only occasionally.
In general, while most of these ferns may be found in both associations,
they are more abundant in beech-maple than in beech-hemlock environment,
and are best developed in the ravines and along their sides. There is little
poison ivy in the area, and such as there is, is confined to the beech-maple
association on higher ground. In places Virginia creeper grows as ground
cover, and in a few places it ascends the trees. In certain locations in the
beech-maple association trailing euonymus forms dense mats as ground
cover.

The vine par excellence in the area is the northern fox grape. It may
form tangles in the tops of large standing trees, or hang in a dense “curtain”
from lofty supports, or create tangles on the ground when the original sup-
porting trees have broken down, letting the whole mass down to ground
level. In the latter case a great opening is made in the forest canopy. Sec-
ondary succession after grapes is obscure, as nothing grows beneath the
grapes in this condition.

Neither mosses nor lichens are particularly abundant in the area. Prob-
ably the creeping hypnum, Amblystegiuum serpens, growing on logs and
stones, is the most common moss in the beech-maple association, and the
cushion moss, Leucobryum glaucum, is the most common in the beech-
hemlock association. The sedge, Carex plantaginea, is one of the well dis-
tributed plants of the beech-maple association.

SAPROPHYTES AND PARASITES

Saprophytic and parasitic plants in the area fall in two main groups—
flowering plants and fungi. They are listed in Table 7. Although the fungi
listed represent four seasons of observation it is realized that the list is far
from complete, as new species are constantly being added. However, it
may be assumed that those species that are of greatest importance in the
area, because of their abundance, regularity of appearance, or wide dis-
tribution, are noted herein.

Doubtless because of the long time during which the natural processes of
decay have been at work in the forest under study, the number of species,
and the abundance of certain fungi, is great. In fact, Mr. Henry C. Beards-
lee, an authority on Ohio fungi, gives it as his opinion that from 1,200 to

THE CLEVELAND MusEuM oF NATURAL History Sci. Pub.

Vol. VI

TABLE 7. Saprophytic and parasitic plants.

1. Flowering plants.
Beech Drops—Epifagus virginiana (L.) Bart.
Squaw Root—Conopholis americana (L.f.) Wallr.
Indian Pipe—Monotropa uniflora L.

2. Fungi.

A. Abundant fungi (in order of abundance)

Woody brackets

Polyporus applanatus Fr.
Polyporus resinosus (Fr.) Schrader.
Polyporus gilvus (Fr.) Schw.
Leathery brackets

Polyporus versicolor Fr.
Polystictus pergamenus Fr.
Stereum spadiceum Fr.

Polyporus hirsutus Schw.

Gilled mushrooms

Collybia radicata Rehl.

Armillaria mellea Vahl.

Pleurotus ostreatus Jacq.
Hypholoma sublateritium Schaeff.
Hypholoma perblexum Pk.
Clitopilus abortivus B & C.
Mycena Leajana Berk.

Coprinus atramentarius (Bull.) Fr.
Collybia platyphylia Fr.

Puff-balls

Lycoperdon pyroforme Schaeft.
Scleroderma aurantium (Vaill.) Pers.
Gelatinous fungi

Tremella mesenterica Retz.

Exidia glandulosa (Bull.) Fr.
Chestnut blight

Endothia parasitica (Murr.) Ander. and Ander.

B. Common fungi (not in order of abundance)

Woody and leathery polypores
Polyporus lucidus (Leys.) Fr.
Polyporus sulphureus (Bull.) Fr.
Fomes fomentarius Fr.
Polyporus brumalis (Pers.) Fr.
Gilled mushrooms

Amanita verna Fr.

Amanitopsis vaginata Roze.
Claudopus nidulans (Pers.) Pk.
Chitocybe illudens Schw.
Clitocybe infundibuliformis Schaeft.
Collybia velutipes Curt.

Collybia strictipes Pk.

Coprinus micaceous (Bull.) Fr.
Crepidotus versutus Pk.
Gomphidius rhodoxanthus Schw.
Hypholoma appendiculatum Bull.
Lepiota procera Scop.
Marasmius rotula Fr.
Marasmius siccus (Schw.) Fr.
Mycena haemotopoda Pers.
Mycena galericulata Scop.
Omphalia campanella Batsch.
Pholiota adiposa Fr.

Pleurotus sapidus Kalchb.
Pleurotus serotinoides Fr.

(beech-maple association)
{beech-hemlock association)
(beech-maple association)

July, 1936

Cc.

Pluteus cervinus Schaeff.
Russula emetica Fr.

Russula fragilis Fr.

Russula mariae Pk.
Strobilomyces strobtlaceus Berk.
Boletaceae

Boletus felleus Bull.

Boletus edulis Bull.

Boletus peckwt Frost.

Boletinus porosus (Berk.) Pk.
Fistulina hepatica Fr.
Puff-balls

Geaster triplex Jungh.
Lycoperdon gemmatum Batsch.
Coral fungi

Clavaria flava Schaeff.

Clavaria cinerea Bull.
Spore-sac fungi (Ascomycetes)
Peziza coccinea Jacq.

A BEECH-MAPLE CLIMAX COMMUNITY

C. Uncommon to rare fungi (not in order of abundance)

Gilled mushrooms

Agaricus sylvaticus Schaeff.
Amanita flavorubescens Atk.
Amanita rubescens Fr.

Armillaria

amianthina Fr.

Cantherellus cibarius Fr.
Cantherellus umbonatus Fr.
Chitocybe albissima Pk.

Chitocybe

clavipes Pers.

Chitocybe fragrans Sow.
Clitocybe multiceps Pk.
Clitocybe nebularis Batsch.

Clitocybe
Clitocybe
Chitopolis

odora Bull.
subcyathiforme Pk.
orchella Fr.

Collybia confluens Pers.
Collybia dryophila Fr.
Coprinus comatus Fr.

Cortinariu

s distans Pk.

Crepidotus applanatus Fr.
Crepidotus malachius B & C.

Enioloma
Entoloma
Flammula
Flammula

jubatum Pk.
rhodopolium Fr.
flavida Fr.
spumosa Fr.

Hygrophorus ceraceus Fr.
Hygrophorus fulgineus Frost.
Hygrophorus pratensis Fr.
Hygrophorus conicus Fr.
Hypholoma hydrophilum Fr.
Hypholoma rugocephalium Atk.

Lactarius

chrysorheus Fr.

Lactarius fuliginosus Fr.

Lactarius
Lactarius
Lactarius

hysginus Fr.
subdulcis Fr.
vietus Fr.

Lentinus ursinus Fr.

Lepiota acutaesquamosa Fr.
Lepiota cristata Fr.
Lepiota naucina Fr.
Leptonia formosa Fr.

Agaricus sylvicola Vitt.
Amanita muscaria L.

Amanita solitaria Bull.
Cantherellus aurantiacus Fr.
Cantherellus rosellus Pk.
Clitocybe adirondackensis Pk.
Clitocybe candida Bres.
Clitocybe cyathiforme Fr.
Clitocybe laccata Scop.
Clitocybe multiformis Pk.
Chitocybe ochropurpurea Berk.
Clitocybe pieceina Pk.
Clitopolis noveboracense Pk.
Collybia butyracea Fr.

Collybia colorea Pk.

Collybia tuberosa Fr.
Cortinarius alboviolaceus Fr.
Cortinarius duracinus Fr.
Crepidotus fulvotomentosus Pk.

Darcomyces deliquescens (Bull.) Duby.

Entoloma niderosum Fr.
Entoloma strictus Pk.
Flammula lenta Fr.
Hygrophorus cantherellus Schw.
Hygrophorus chlorophanus Fr.
Hygrophorus miniatus Fr.
Hygrophorus coccineus Schaefi.
Hypholoma echinoceps Atk.
Hypholoma lachrymabundum Fr.
Inocybe radiata Pk.

Lactarius cinereus Pk.
Lactarius helvus Fr.

Lactarius piperatus Scop.
Lactarius trivialis Fr.
Lactarius volemus Fr.

Lenzites betulina Fr.

Lepiota clypeolaria Fr.

Lepiota metulaespora B & Br.
Leptonia asprella Fr.
Marasmius delectans Morg.

30 THE CLEVELAND Museum oF NATURAL HIsToRY

Marasmius elongatipes Pk.
Marasmius spongiosus B & C.
Mycena albolutea Pk.
Mycena cohaerens Fr.
Mycena minutula Pk.
Mycena polygramma Bull.
Mycena pura Fr.

Nolanea pascua Fr.

Panus strigosus B & C.
Panus stypticus Fr.
Paxillus lepista Fr.
Pholiota erebia Fr.
Pholiota mutabilia Fr.
Pholiota spectabilis Fr.
Pholiota squarrosoides Pk.
Pleurotus petaloides Bull.
Pluteolus reticulatus Fr.
Pluteus granularis Pk.
Russula alutacea Fr.
Russula lepida Fr.
Russula pusilla Pk.
Russula sordida Pk.
Russula uncialis Pk.
Russula vinosa Lindb.
Tricholoma laterarium Pk.
Volvaria bombycina Schaeff.

b. Boleti
Boletus alutaceus Morg.
Boletus chrysenteron Fr.
Boletus scaber Fr.

c. Puff-balls
Calvatia cyathiformis Bosc.
Lycoperdon echinatum Pers.
Cyathus striatus Wiftld.

d. Spore-sac fungi (Ascomycetes)

Bulgaria inquinans Fr.
Gyromitra esculenta Fr.
Morchella esculenta Pers.
Peziza badia Pers.

Peziza scutellata

e. Polypores
Daedalia ambigua Berk.
Daedalia confragosa Boton.
Merulius lachrymans (Jacq.) Fr.
Polyporus frondosus Fr.
Polyporus picipes Fr.
Polyporus squamosus Fr.

f. Other species
Clavaria amethystina Bull.
Clavaria inequalis Fl. Dan.
Clavaria muscoides Fr.

Hydnum caput-urss Fr.
Hydnum erinaceus Bull.
Hydnum septentrionale Fr.
Tremella albida Huds.
Tremellodon gelatinosum Pers.

Hyroneola auricula-judae (L.) Berk.

Craterellus cantherellus Schw.
Stereum sericium Schw.

Phallus raveneli B & C.

Marasmius oreades Fr.
Marasmius velutipes B & C.
Mycena alkalina Fr.

Mycena filopes Fr.

Mycena peliantha Fr.

Mycena pulcherrima Pk.
Nectria cinnibarina (Tode.) Fr.
Omphalia fibula Fr.

Panus rudts Fr.

Panus torulosis Fr.

Paxillus panuoides Fr.

Pholiota marginata Batsch.
Pholiota praecox Pers.

Pholiota squarrosa Mill.
Pleurotus corticatus Fr.
Pleurotus ulmarius Fr.

Pluteus admirabilis Pk.
Pluteus longistriatus Pk.
Russula foetans Fr.

Russula lutea (Huds.) Fr.
Russula purpurina Quel. & Sch.
Russula rubescens Beards.
Russula sanguinea Fr.
Stropharia squamosa (Pers.) Fr.
Tricholoma personatum Fr.

Boletus castaneus Bull.
Boletus diochrous Ellis.
Boletus subtomentosus Fr.

Geaster hygrometricius Pers.
Lycoperdon subincarnatum Pk.

Geoglossum

Helvella crispa Fr.
Peziza aurantia Pers.
Peziza odorata Pk.
Xylaria polymorpha Pers.

Favolus canadensis Klotsch.
Polyporus cinnibarinus Jacq.
Polyporus galactinus Berk.
Polyporus radicatus Schw.
Polyporus umbellatus Fr.

Clavaria aurea Schaeff.
Clavaria mucida Pers.
Clavaria vermicularis Scop.

Hydnum coralloides Scop.
Hydnum repandum (L.) Fr.

Tremella lutescens Pers.
Tremalitelia nucleata (Seb.) Rea.

Mutinus elegans (Mont.) Ed. Fischer.

Sci. Pub.
Vol. VI

July, 1936 A BEEcCH-MAPLE CLIMAX COMMUNITY 31

1,500 species of the larger fungi should eventually be listed in such a forest
as this. Of the woody sporophores that are persistent as brackets throughout
the year, those of Polyporus applanatus are by far the most abundant.
Usually these are the first of the brackets to appear upon newly fallen tree
trunks, and often appear upon living trees. Even in such a case, however,
they are probably growing on dead wood (Von Schrenk and Spaulding
1909). This fungus has been noted upon the decaying logs of practically
all of the species of trees within the area.

Of the leathery polypores, Polyporus versicolor is in evidence every-
where, and usually its banded ruffles are the first fungus growth to appear
upon fallen logs or branches of whatever species. Stereum spadiceuwm and
Polystictus pergamenus may frequently be found in close competition with
Polyporus versicolor. The service of these fungi and a few other closely
related species in the forest under study in helping return to the soil the
mass of woody plant débris which otherwise would continually accumulate
can scarcely be overestimated. Bray (1915) points out that if it were not
for some such disintegrating force at work in the forest, the surface of the
ground would soon become clogged to such an extent as to make further
plant growth impossible. Considering the number of species of fungi re-
corded at North Chagrin, and the great abundance of their sporophores at
certain seasons, it is apparent that the humus must be thoroughly permeated
with fungus mycelium, and that the fallen leaves, branches, and tree trunks
are all “hot beds” of fungus activity.

The presence and the fruiting bodies of slime moulds (Myxomycetes)
have been frequently noted, but no attempt has as yet been made to study
their distribution or significance.

DYNAMICS OF SUCCESSION

Throughout the area the presence of old stumps, logs, and standing dead
trees indicates something of the character of the forest of the recent past.
Despite the passage of more than 60 years it is possible to recognize three
species of trees represented by the stumps said to have been cut in 1871.
These are oak (probably red oak, as this is the present most abundant spe-
cies of oak), tulip, and chestnut. The species maps of tulip and red oak
(Fig. 10) show both the living trees and the old stumps. It is apparent that
red oak was formerly a constituent of the interior forest in much greater
numbers than now. The 50 oak stumps that were measured showed an
average diameter, without bark of sapwood, of 38.2 inches (97.03 cm.) at
approximately 3 feet (91.44 cm.) from the ground. The average diameter
of the 50 largest living red oaks is 30.2 inches (76.7 cm.) Apparently the
stumps represent a considerably more mature stand than do the present
trees.

32 THE CLEVELAND Museum oF NATURAL HIsToRY eA Ee

There are 32 stumps of tulip recognizable at the present time. Measure-
ments of these show an average diameter of 32.8 inches (83.31 cm.) without
bark, at approximately 3 feet from the ground. The largest 32 living tulips
show an average diameter of 29.6 inches (75.18 cm.), a size not greatly
below that of the old stumps. A study of the species map (Fig. 10) indi-
cates that the position of tulip in the community has changed little, if any,
in the past 60 years.

The chestnut stumps cut in other years are few in number and are all
located in present chestnut territory, indicating no recent movement of
chestnut.

On the forest floor it is possible to recognize logs of beech, sugar maple,
sassafras, tulip, tupelo,2, cucumber, and hemlock. Of these, sassafras,
cucumber, and hemlock are the only species that, from the position of the
logs in the area, indicate a change in distribution as compared with the pres-
ent. Of the standing dead trees, only cucumber and hemlock exhibit change
of distribution. Sassafras and cucumber are apparently in process of being
eliminated from the interior forest, as both formerly occurred there but are

now practically limited to the spurs or their immediate vicinity (Fig. 10).

Hemlock appears to be rapidly decreasing in numbers. Figure 12 shows the
location of 85 standing dead hemlocks measuring from 10 inches (25.4 cm.)
to 28.6 inches (73.2 cm.) in diameter. The discovery of the larvae of the
flat-headed hemlock borer (Melanophila fulvogutiata Harr.) beneath the
bark of many trees leads to the supposition that the activities of this insect
is the immediate cause of the death of these otherwise apparently sound hem-
locks. A comparison of Figure 12 with Figure 9 will show that these trees
are in the heart of the present hemlock areas.

The rate of reproduction may have a large bearing upon the matter of
stability or change in status of the forest constituents. The seeding of both
beech and sugar maple is periodically abundant, but beech seedlings do not
survive as well as those of sugar maple in the early stages of their develop-
ment. In one area of approximately 25 feet (7.62 m.) square, 12 beech trees
of from 2 to 4 seasons growth were counted, while the number of sugar
maples of the same age in the same area was estimated to be in the neighbor-
hood of 3,000—a proportion of 1 beech to 250 sugar maples. Yet the high
mortality of young sugar maple saplings later seems to more than make up for
this great difference in the early years of development. At present the seed-
ing of both of these trees seems to be adequate to the needs of replacement
of the species to make good the annual losses from the ranks of the old trees,
and beech has the additional advantage of sending up suckers from the roots.

? Wherever “tupelo” is used in this paper the author refers to the common black gum,

Nyssa sylvatica Marsh., and not Nyssa aquatica Marsh. which is most commonly called
“tupelo” throughout the Southeast —Ed.

July, 1936 A BrerecuH-MapPLE CLIMAX COMMUNITY 33

LOCATION OF BELT TRANSECT
LOCATION OF 85 STANDING,
DEAD HEMLOCKS 95 /
TO.22.2 IN. (24.13 TO
56.5CM) IN DIAMETER

&
®

[The PLIST TTT TL Lg K)

LITT RT

TRANSECT

Fic. 12. Location of standing dead hemlocks.
According to Illick and Frantz (1928) under favorable conditions in Penn-
sylvania dense stands of beech will develop from root suckers alone.

While the seeding of red maple is at times very abundant, germination is

poor, and seedlings and saplings do not survive in competition with those of

beech and sugar maple.

Location of belt transect.

34 THE CLEVELAND Museum oF NaturRAL History ae a

The hemlocks of the area at times bear abundant crops of seeds, but
germination has long been practically at a standstill. Apparently because
of more favorable moisture conditions there was a fair amount of germina-
tion of hemlock seeds in 1935, but it remains to be seen whether or not a
succeeding dry summer may wipe them out. In the hemlock areas it is quite
noticeable that the dead leaves of beech and maple make up the bulk of the
litter under the trees.

Both tulip and white ash bear seeds regularly and abundantly, and their
seeds germinate well, but neither species long survives in competition with
seedlings of beech and sugar maple. It is only in those places where sun-
light has been let in, usually because of the fall of a large tree, that ash
and tulip are able to raise their heads and make a place for themselves in the
forest community. Under such conditions they make rapid growth.

Red oak and white oak often bear large quantities of acorns. Red oak
in particular often so covers the ground with its seeds that they blanket
everything else. Yet there are practically no oak seedlings or saplings of
any kind in the forest.

The few hickories in the area produce good crops of nuts, yet there are
no seedling or sapling hickories to be found away from the forest edge.

Cucumber and tupelo are regular seeders, and a considerable num-
ber of very young trees of these species are to be found in the neighbor-
hood of the old trees. In addition, both of these species will sucker from
exposed roots or the bases of stumps.

In order to study more definitely the relative significance of beech, sugar
maple, and hemlock in the climax community, a belt transect was charted
from a point in the beech-maple association on the higher ground, almost
directly east to the edge of the bluff, thus traversing the entire width of the
most extensive beech-hemlock territory in the area. Reference to Figure
12 will show its location.

The belt was 10 meters (32.8 feet) in width, and extended for a total
distance of 360 meters (1181.1 feet). It was subdivided into 45 quadrats,
each 10 by 8 meters (32.8 by 26.2 feet). The approximate position of all
trees 2.5 cm (1 inch) or over in circumference was charted in each of these
quadrats, and the trees measured breast high by tape. This chart is shown
in Figure 13. A study of it reveals the following facts:

1. Beech is represented by large trees throughout the transect—32 of
these ranging from 24 cm. (9.4 inches) to 80 cm. (31.5 inches) in diameter.

2. Sugar maple decreases in size as the hemlock area is approached,
until it is represented only by saplings, and then soon drops out altogether.

3. Many decaying logs of hemlock on the ground are encountered before ©
the present beech-hemlock association is reached. This condition persists well

July, 1936 A BrEEcH-MAPLE CLIMAX COMMUNITY 35

~@BEECH @RED OAK CUCUMBER @ WHITE OAK Ch WILD GLACK CHERRY
i oO SUGAR MAPLE 77) TULIP rR@® RED MAPLE A WHITE ASH © STANDING DEAD TREE
+DHEMLOCK ©CHESTNUT © SASSAFRAS Ty TUPELO LINES INDICATE HEMLOCK LOGS

8 0 he? F

QUADRATS 8x10 METERS (26.2%32.8 FEET) —— TREE SIZES DIAGRAMMED LARGER THAN SCALE
DIAMETER DIAMETER @ DIAMETER DIAMETER

40 IN. (101.6 CM) 30 IN.(76.2CM) 20 IN. (50.8 CM) ° 40 IN. (25.4 CM)

Fic. 13. Belt transect.

into the present beech-hemlock territory, but becomes less marked as the
best hemlock development is reached. Practically all down timber in the
transect is hemlock.

4. Reproduction of both beech and sugar maple, as represented by sap-
lings and young growth in the transect is good. Reproduction of hemlock
is poor—almost negligible.

5. The presence of large tulip, tupelo, cucumber, and chestnut is
noted—the tulip outside the beech-hemlock territory, the other species as-
sociated with the hemlocks. The presence of oaks is noted as the edge of
the bluff is reached.

6. Red maple appears as a rather constant but not important element in
the transect.

A consideration of the age of the community under study may shed some
additional light on the dynamics of succession. Table 8 shows the distribu-
tion of the most important tree species through certain size classes. It will
be noted that all of the species here shown exhibit a peak of numbers in
what might be called the middle size classes, with diminishing numbers to-
ward both larger and smaller sizes. Although not shown in this table it
is a fact that both beech and sugar maple show much larger numbers in
smaller sizes than those included in Table 8. This is shown by the counts

36 THE CLEVELAND MusEuM oF NATURAL HIsToRY Set fe

recorded in Table 5, as well as by general observation. Sugar maple espe-
cially, in certain locations, has produced a tremendous number of saplings
of from an inch to three inches in diameter. These dense stands of young
maples are not of general distribution. They probably represent the heavy
seeding of certain old trees under especially favorable circumstances in for-
mer years. Mortality among such young trees must be very great when a
certain critical point in their development is reached, as Mr. Percy Parker,
who has lived many years in the neighborhood, tells the writer that certain
areas that are now practically clear of understory trees used to be densely
crowded with sugar maple saplings when he used to hunt rabbits in these
woods as a boy. In this connection it is interesting to note that one of the
very areas thus pointed out by Mr. Parker and now devoid of young sap-
lings, was recently covered (1935) with hundreds of thousands of sugar
maple seedlings, standing so closely together as to provide a ground cover of
continuous green throughout the summer, where in the previous years of this
study the aspect had invariably been that of the almost unbroken brown of
dead leaves.

It is of interest to note (Table 8) the decrease in numbers of individuals
as the older trees (larger sizes) are considered. They seem to be approach-
ing a limit of size that is rather definitely set.

TABLE 8. Numbers of trees in different size classes.

DIAMETERS

Inches......... 95-12 | 12-15 |] 15-18] 18-21 | 21-24 | 24-27) \eagenomnameeae

Centimeters.....|24.1 - 30.4|30.4 - 38.1|38.1 - 45.7|45.7 - 53.3|53.3 - 60.9/60.9 - 68.5|68.5 - 76.2|76.2 - 83.8
Beech hl. 541 ch 17 71 132 112 162 81 63 10
Sugar Maple....... 127 173 105 78 61 31 10 2
Red Maple........ 56 93 83 48 29 9 4 3
Hemlock.......... 79 103 73 39 26 2 2 0
Chestnut.......... 13 38 44 55 48 19 24 15
uy soe 29 19 4 1 6 5 4 5
White Ash......... 10 12 4 4 3 6 3 1
Red Oak.......... 5 7 9 14 12 20 10 10

DIAMETERS

Inches......... 33-36 | 36-39 | 39-42 | 42. 45 45 - 48 48 «51s ee 63.2

Centimeters... .|83.8-91.4/91.4 - 99.0|99.0-106.6] 106.6 - 114.3 114.3 - 121.9]121.9- 129.5]...... 160.5
IBECCIT seine nites 9 4 3 1
Sugar Maple....... 1 1 0 1
Red Maple........ 3 2 1 1
BeMIGCK 5.44 Siecle» 0 0 0 0
Chestnut.......... 6 3 2 2
ANTM OSE yarns olace 4 3 2 1
White Ash......... 2 0 0 0 i‘
Red Oakriss..0/s)0% 3 0 z 0 1 1 1

July, 1936 A BreecHo-MapiLe CLIMAX COMMUNITY 37

To this the red oak seems to be the only exception, although it is probable
that if it were not for the cutting of some large tulips in 1871 tulip would
appear in sizes beyond those of the present table.

It has been possible to make counts of annual rings in a few cases of
trees overturned in the area by a severe wind storm June 26, 1931. These
records are shown in Table 9. In estimating the age of such a tree, a con-
siderable period of time must be allowed for early stages of growth, as such
trees growing from the forest floor, are greatly repressed during the early
years.

TABLE 9, Counts of annual rings of trees overturned by storms.

BEECH
Distance from cut Annual rings Estimated age of
Diameter at cut to base of tree at cut tree in years
22 me) (55.8 cm.) 43 in. (1.09 m.) 229 250
20 in. (50.8 cm.) 25) fe) (7 -62)m.) 190 220
14in. (35.5 cm.) 10 ft. (2.54 m.) 105 125
13.5 in. (34.3 cm.) 10 ft. (2.54 m.) 126 150

SuGar Mapie

27 in. (68.6 cm.) 25 ine (76.2 em.) 174 190
25m. (63.5) cm.) 40 ft. (12.2 m.) 140 190
2tin. (53.3 cm.) P2.iney(G0.5 cm.) 120 130
21 in. 3(53.3' cm.) 27 in. (68.6 cm.) 176 190
2iving, §(53.3:cm.) 20 in. (50.8 cm.) 160 180
20.5 in. (52.1 cm.) 29 in. (73.7 cm.) 134 160
20 in. (30.8 cm.) 33 in. (83.8 cm.) 150 160
18in. (44.7 cm.) 20 in. (50.8 cm.) 182 200
18in. (44.7 cm.) 20 in. (50.8 cm.) 168 185
16in. (40.6 cm.) 22 in. (55.8 cm.) 158 175
14m. (35.5 cm.) 24 in. (61.0 cm.) 126 140
fame. (33... cm.) 28 ins CAL cm®) 129 145
PSyiniey C35 41) cm.) 32 in. (81.3 cm.) 100 115
HeEMLocK
22in. (55.8 cm.) 20 in. (50.8 cm.) 164 175

A comparison of these tree sizes with the sizes of standing trees (Table 8)
in the area shows that 39 per cent of the beeches and 13 per cent of the
sugar maples making up this forest are as large, or larger, than the largest
of which the annual rings were counted. This would indicate the age of the
present forest to be well over 250 years.

The span of life of the sugar maple in this location seems to be deter-
mined by its size in relation to the soil. The humus is shallow, and the
compact character of the subsoil seems to restrict the roots of this species
to the soil above it—usually a matter of about 12 inches (30.5 cm.). Ap-
parently few sugar maples above a certain size limit can long maintain them-

38 THE CLEVELAND MusEuUM oF NATURAL History Pe ae

selves in this shallow soil against such severe wind storms as sometimes
visit this forest. On the other hand, the life span of the beech seems to
be determined by its susceptibility to fungus attack. There is probably no
large beech tree in the area which is not hollow, at least at the base, the heart-
wood having been reduced to punk by the various species of fungi which
seem to find an easy entrance to the tissues of this species. When finally
the sapwood is affected, the tree will ultimately be twisted off its base by a
wind storm, leaving the hollow stub standing. Apparently about 250 to 300
years is the limit of life for either the beech or the sugar maple in this loca-
tion. There is need, therefore, for continual replacement of the dominants
to make good the losses which more or less regularly occur.

The foregoing facts, taken together, clearly warrant the conclusion that
in the area under study a gradual change in the status of the forest com-
ponents has been in progress for some time, and the forces operating to
bring about this change are operating at the present time. The conclusion
that the hemlocks are being displaced by the beech and the sugar maple is
inescapable. That the hemlocks formerly occupied much more territory
than they now do is indicated by their remains in an area now completely
occupied by the beech-maple association. In this movement the beech seems
to play the leading part. Not only may beech hinder germination of hem-
lock by creating a humus unfavorable to the development of hemlock seed-
lings, but it may, by its dense shade, prevent the normal development of
young hemlocks beneath its canopy, or by root competition in dry seasons
reduce soil moisture available to neighboring hemlocks to the point where
it ceases to be sufficient for hemlock requirements. The fact that beech
roots more deeply than sugar maple in this environment may better fit it to
play the part of entering wedge in displacing hemlock here. However, it
may be expected that sugar maple will be more largely represented in this
location in the future than it is now.

The need of plants for light is preeminent. Zon and Graves (1911) point
out that early in life all plants are more or less tolerant of shade, but as they
increase in size, their requirements for light become more and more definite,
and that these requirements differ for different species. Burns (1923),
studying the light requirements for 14 species of forest trees, found that
each had a specific minimum requirement below which it could not live. The
three trees with the lowest requirements he found to be, sugar maple low-
est, beech next, and hemlock next. Daubenmire (1930), studying evapora-
tion rate, light, soil acidity, and soil moisture under hemlock in Indiana,
attempted to correlate the difference between hemlock and beech-maple.
The results indicated an equal degree of mesophytism in the two associa-
tions. Studies of hemlock and its environment have been made by Moore,
Richards, Gleason, and Stout (1924). While some slight differences were

July, 1936 A BEECH-MAPLE CLIMAX COMMUNITY 39

found in the evaporation rate and in soil and air temperatures as compared
with the hardwood forest, these do not seem significant enough to be
recognized as controlling factors in the distribution of hemlock.

Apparently hemlock is not restricted in its location, as compared with
the adjacent beech-maple association, by either temperature or moisture con-
ditions, or by the chemical constitution of the soil; but rather, it is in process
of elimination by competition within areas formerly occupied by it but now
being gradually taken over by beech and sugar maple as dominants. The
view that hemlock is thus being displaced is in accord with the opinion
expressed by Weaver and Clements (1929) that the hemlocks of this region
represent a remnant of the so-called “Lake Forest” to the north, returning
with the retreat of the glacial ice, and now existing here only as small relict
areas.

The fact that no chestnut saplings, and but very few smaller chestnut
trees are to be found within the area, and that chestnut and hemlock were
formerly very closely associated (Fig. 9) apparently on more or less even
terms, leads the writer to the opinion that chestnut as well as hemlock would
have fallen in competition with the beech-maple association, had not the
“chestnut blight’? wiped out the chestnuts before their time. For this rea-
son chestnut may not be expected to “come back” in this environment
naturally.

Undoubtedly the few oaks, hickories, sassafras, and other trees of sub-
climax types will gradually be eliminated through failure of reproduction,
though sassafras has the great advantage of being able to reproduce by suck-
ers from the roots. The presence of these trees, normally associated with
the oak-chestnut forest, suggests an inter-relation of hemlock with oak-
chestnut on the one hand, and beech-maple on the other, such as might have
produced at one time an oak-chestnut-hemlock mictium which has now gone
over to beech-hemlock.

That cucumber, and probably tupelo, have suffered displacement from
the interior forest is clear, yet because of the steady though small reproduc-
tion rate of both species, and their commanding size when fully grown, they
will probably continue for a long time as associates with the climax.

SECONDARY SUCCESSION

Under present conditions, the causes of secondary succession within the
area are limited to denudations occurring by reason of the washing away
of humus and top-soil at times of heavy rains, the slipping of earth and
shale on the sides of the ravines due to erosion, and to the letting in of
sunlight where breaks in the forest canopy occur because of the death of
large trees which may either fall or remain standing, or whose tops or large
branches may be broken off.

40 THE CLEVELAND Museum oF NATURAL History Bok

It is the uprooting of the large trees, exposing a more or less circular
area of hard yellow clay, that causes most if not all of the secondary suc-
cession noted in the area by the writer. Such a depression may hold water
for a large part of the year, and for this reason many seeds will not germi-
nate upon it. From the edges of the torn mat of humus pokeweed is usually
the first plant to appear. Commonly red-berried elder and high-bush black-
berry are found along with the pokeweed. On the bare wet clay the spores
of ferns, and the seeds of violets, wood sorrel, and great lobelia will germi-
nate. Tulip and white ash frequently appear, but neither beech nor sugar
maple will start on this surface.

From studies which have been started within the area in several local-
ities where secondary succession is in process, but which cannot be re-
ported on in detail here, it appears that tulip and white ash are the species
that thrive, when the opportunty offers for rapid development in unoccupied
territory. This accounts for the rather general distribution of these two
species throughout the climax, both at the present time, and in the case of
the tulip, formerly.

ECOLOGICAL CLASSIFICATION OF PLANTS

The dominant plants in any biotic community are considered to be those
which, by reason of their size, abundance, and distribution, largely determine
the conditions under which other organisms shall live in association with
them. In the forest the dominants are usually trees. They are exposed di-
rectly to the sun, rain, snow, and wind; and other organisms mostly live
underneath them. Beneath the trees temperature, light, evaporation rate,
humidity, precipitation, wind, and other factors in the environment may be
greatly modified. Only such plants and animals as are adapted to life un-
der these conditions can exist here. The dominants therefore not only raise
barriers against certain forms of plant and animal life—they invite others.

Primary dominants are those which, by reason of their wide and more
or less even distribution and abundance, exercise their influence over the
greater part of the community. Secondary dominants are those dominants
which, by reason of their less frequent occurrence, do not exercise as great
influence over the community as such. Their occurrence in the community,
however, is rather regular. Incidental dominants, in this paper, are such
trees as attain large size, and so exert an influence over a limited area, but
which do not occur in numbers, or with any degree of regularity in the com-
munity. Subdominants are all other plants. They do not attain great size,
but have adapted themselves to conditions of existence below the dominants.
On this basis the plants of the area may be classified as in Table 10.

July, 1936 A BrecH-MaApPLE CLIMAX COMMUNITY 41

TABLE 10. Ecological classification of plants.

In beech-hemlock-oak- In ravines
In beech-maple association (chestnut) mictium (flood-plain extensions)

1. Primary dominants

Beech Beech Hemlock
Sugar Maple Hemlock
(Chestnut)

2. Secondary dominants

Red Maple Red Maple
Tulip Red Oak
White Ash

Northern Fox Grape

3. Incidental dominants

ey
—— ee ee

Shagbark Hickory Shagbark Hickory American Elm
Cucumber Cucumber Basswood
Red Oak Tupelo Slippery Elm
White Oak Sassafras Butternut

White Oak Black Walnut

Wild Black Cherry Bitternut

Pignut

Black Birch

Scarlet Oak

4. Sub- dominants

Hop Hornbeam Hop Hornbeam Shrubs, vines, herbs, ferns,
American Hornbeam American Hornbeam and other plants.

Shrubs, vines, herbs, ferns, | Flowering Dogwood
and other plants, as listed | Shadbush
in tables 6 and 7. Shrubs, vines, herbs, ferns, and
other plants as listed in tables
6 and 7.

CHARACTER OF ANIMAL) POPULATION

MertTuHops oF STUDY

Contrasted with the study of the plants of any area the study of its
animal population presents an entirely different and much more difficult
problem. Animals do not “stay put” as do plants. If the ecologist would
really learn to know the animal content of an area, he must become so
familiar with it that he feels thoroughly “at home” in it, and should
achieve, in some degree at least, such a sympathetic attunement to the
ebb and flow of its life activities that he becomes conscious of changes
while they are in progress, and senses the significance of small matters
as they arise. He must acquire the ability to move quietly and easily
about, making a minimum of disturbance, while the senses of sight, hearing,
and smell bring him information for his record.

42 THE CLEVELAND Museum oF NATURAL HISTORY A Pub.

While the methods of study of animals in their natural habitats must
vary in accordance with the season, and often with the species studied, there
are some general methods which, if carefully followed, should always offer a
fair chance of definite returns. Such general methods as were used by the
writer in this study were:

1. Regular and frequent visitation of the area. The writer was fortu-
nately so situated that he could and did devote the Mondays of each week
throughout the entire four years of this study to such visitation, with the
exception of six scattered weeks, when observations were made by others
under his direction. Familiarity with the area and its inhabitants was thus
built up, and a picture of consecutive changes as they occurred secured,
which probably could have been realized accurately in no other way. In ad-
dition to these extended weekly observations it was often possible to aug-
ment the record by more limited occasional visits in connection with other
matters.

2. An increasing keenness of observation and interpretation of things
seen and heard was deliberately sought after. A bird’s feather on the
ground, the scattered remnants of a meal, a dead shrew on a log, the drop-
pings of animals, the barred owl’s cast pellets, the character of wood-
pecker “workings,” and many sounds and smells, all raised questions for
which the correct answers were sought, even though considerable time might
elapse between question and answer, and sometimes experiment was neces-
sary for the solution of the problem.

Thus the presence of a heretofore unsuspected mammal (later confirmed
by securing two specimens in the flesh) was determined through the dis-
covery of the tiny jaw bone of the smoky shrew; and a method of ascer-
taining the presence of the seldom-seen flying squirrel was worked out by
feeding hickory nuts to several species of captive squirrels, and noting that
the flying squirrel, (and in fact the other species also) left a characteristic
“signature” upon the nut shell.

3. Orderly routine in observation and recording on the spot. On each
weekly visit the same course was followed, covering the entire area. Fre-
quently the direction of travel was reversed, so that the same part of the
area might be visited at different times. During this weekly survey an ef-
fort was made to identify accurately each species seen or heard; to make
as complete a count of individuals as possible, or in the case of large num-
bers, to make a close estimate of numbers based on unit counts; to locate
the occurrence of each individual on a small map carried for the purpose
each week; to make notes of conditions of weather, changes in the plant or
animal life observed, activities, relationships, or other facts considered sig-
nificant. As this work was, with the few exceptions noted, always per-
formed by the same person, usually alone, differences which might be due

July, 1936 A BreecH-MaApPLEeE CLIMAX COMMUNITY 43

to individual variances were eliminated, and the resultant data should be
fairly comparable from one period to another. In estimating populations
which are not restricted either to beech-hemlock or beech-maple environ-
ment, account does not have to be taken for what Leopold (1933) calls
“blanks,” as the entire area is essentially “forest” throughout. Even the
area of the trails does not have to be figured out, as these are a very much
used part of the habitat. All observations were recorded under appropriate
headings on a temporary record carried for the purpose, and later transcribed
to a permanent record, usually on the evening of the same day.

4. Concentration, at times, on special phases of animal behavior. Such
were the studies of animal tracks in the snow, the location of the nesting
territories of birds, and the home ranges of mammals, the study of food
habits as special opportunities presented themselves, and the special study
of the abundance and distribution of mice and shrews.

5. Visitation of the area at night. As the activities of some animals
are carried on mainly after dark, it was considered of importance to visit
the area a number of times, for varying periods, during the hours of dark-
ness.

6. Observation of captive animals. While it is recognized that animals
in captivity undoubtedly behave differently than in a state of natural free-
dom, it is also evident that much may be learned as to the character of the
animal, and some understanding gained as to its equipment to meet competi-
tion in its natural environment, from a study of it at close quarters, even
though under restraint. Opportunities were at hand during the summers
to thus become acquainted with the New York weasel, raccoon, opossum,
skunk, woodchuck, cottontail rabbit, red squirrel, chipmunk, flying squirrel,
white footed mouse, pine mouse, barred owl, Cooper’s hawk, red-tailed
hawk, red-shouldered hawk, crow, and pilot blacksnake.

THE MAMMALS OF THE AREA

Table 11 gives the list of mammals whose presence in the area is known
from direct observation. Representatives of all of these except the Virginia
deer and the fox squirrel have been in the hands of the writer at various
times, and skins of all of the species of mice, shrews, moles, bats, and chip-
munk are deposited with the Cleveland Museum of Natural History. Sci-
entific names are as given in the List of North American Recent Mammals,
Bulletin 128 of the United States National Museum, with the exception of
the eastern chipmunk, which is described by Howell (1929).

While the numbers and relative abundance of mammals in the area will
always be subject to considerable fluctuation, the common species listed in
Table 11 will usually be found in the order given; the most abundant being
placed first. for the less common species enough information is not yet
at hand to warrant an attempt to estimate abundance.

44 THE CLEVELAND MusEuUM oF NATURAL HISTORY Sci. Pub.

Common species
Short-tailed Shrew

Northern White-footed Mouse

Eastern Chipmunk

Northern Gray Squirrel

Southern Red Squirrel

Small Eastern Flying Squirrel

Cottontail Rabbit
Southern Woodchuck
Eastern Raccoon
Eastern Skunk
Virginia Opossum
Eastern Red Fox
Domestic Dog
Domestic Cat

Less common species

Smoky Shrew
Hairy-tailed Mole
Star-nosed Mole
Silver-haired Bat
Big Brown Bat
Red Bat

New York Weasel
Fox Squirrel
Pine Mouse

Vol. VI

TABLE 11. The mammals of the area.

Blarina brevicauda talpoides (Gapper).
Peromyscus leucopus noveboracensis (Fischer).
Tamias striatus fisheri Howell.

Sciurus carolinensis leucotis (Gapper).
Sciurus hudsonicus loquax Bangs.
Glaucomys volans volans (Linnaeus).
Sylvilagus floridanus mearnsi (Allen).
Marmota monax monax (Linnaeus).
Procyon lotor lotor (Linnaeus).
Mephitis nigra (Peale and Beauvois).
Didelphis virginiana virginiana Kerr.
Vulpes fulva (Demarest).

Sorex fumeus fumeus (Miller).

Parascalops breweri (Bachman).

Condylura cristata (Linnaeus).

Lasionycteris noctivagans (Le Conte).

Eptesicus fuscus fuscus (Beauvois).

WNycterts borealis borealis (Miller).

Mustela noveboracensis noveboracensis (Emmons).
Sciurus niger rufiventer (Geoff.).

Pitymys pinetorum scalopsoides (Audubon and Bachman).

Meadow Mouse Microtus pennsylvanicus pennsylvanicus (Ord).
Hudson Bay Jumping Mouse Zapus hudsonius hudsonius (Zimmerman).
Woodland Jumping Mouse Napaeozapus insignis insignis (Miller).
Virginia Deer Odocoileus virginianus virginianus (Boddaert).

The above list of 25 mammals (omitting dog and cat) contains 49 per
cent of the entire list of mammals (51) listed by the Ohio Department of
Agriculture as now to be found in the State (Bull. 54, Bureau Scientific Re-
search, 1931).

That the bison (Bison bison (Linnaeus) ), American elk (Cervus can-
adensis canadensis (Erxleben) ), Virginia deer (Odocoileus virginianus vir-
gmianus (Boddaert) ), black bear (Ursus americanus americanus (Pallas) ),
and panther (Felis cougar Kerr) were once abundant in this region is at-
tested by early writers. In view of the fact that all of these animals were
completely exterminated from northern Ohio many years ago, it is interesting
to find evidence of the return of one of them, the Virginia deer, to the
locality. In view of the present overstocked condition of the deer ranges in
western Pennsylvania (Clepper 1931) it would not be surprising to find deer
wandering into northeastern Ohio from that direction.

DISTRIBUTION AND ABUNDANCE OF MAMMALS

In late July and early August 1932 some line trapping with spring mouse
traps throughout the area demonstrated the very general distribution of short-
tailed shrews and white-footed mice in all parts of the forest. It appeared
that a catch could be made at every stump, or decaying log, or litter of sticks.
Tunnels and runways were also found everywhere under the humus and

July, 1936 A BEECH-MAPLE CLIMAX COMMUNITY 45

loose leaf-litter. Apparently the habitat was then occupied to the saturation
point by mice and shrews. From a third to a half of the 98 animals trapped
were either wholly or partially eaten, though the traps were inspected daily,
and were usually under cover. This in itself indicated a large shrew popula-
tion. The conditions of that autumn have not been duplicated since.

In late September and early October of the same year a more definite
attempt was made to secure data that could be used as a basis for estimating
the number of these two animals. Five quadrats were laid out in carefully
selected territory, each 10 meters (32.75 feet) square. The location chosen
for each was such as to make it typical of the whole area. Two were in
beech-hemlock environment, and three were in beech-maple. One of the
three in beech-maple environment had in it no stumps or logs or cover of
any kind except the humus and leaf litter of the forest floor. The others
included various types of shelter such as are commonly distributed over the
area—tree roots, old logs, stumps and the like. Mouse traps of the usual
spring-catch variety were used, baited with both oatmeal and raw beef, and
usually set in groups of threes in runways that showed evidence of use, or
in sheltered places. Trapping in each quadrat was continued until several
days had passed without a catch. Usually this meant about two weeks of
total time. It was then assumed that all of the mice and shrews using the
quadrat as a hunting ground had been captured. Traps were inspected daily,
often more frequently. Careful records were kept.

If the average catch of all five quadrats is taken as representing the pop-
ulation of an average 10 meter square for the whole area, then the popula-
tion may be computed for any unit of the area. Later studies (unpublished)
made by Mr. B. P. Bole, Jr., of the Cleveland Museum of Natural History,
have demonstrated that the drift of small mammals from neighboring terri-
tory into the quadrat, especially at times when populations are high, is
greater than was realized at the beginning of this study. It was originally
felt that an offset existed in the loss of animals eaten and removed from the
traps, large enough to counterbalance the entrance of others into the quad-
rat during trapping operations. The figures given in Table 13 for short-
tailed shrews and white-footed mice are therefore undoubtedly too high, yet
they are used in this paper as they establish a basis for comparisons with
subsequent years during which the same trapping methods have been fol-
lowed.

Accordingly, in September 1933 five quadrats of the same size as those
used in 1932 were set up adjoining the quadrats of 1932, and trapped. The
original five quadrats were again trapped in the autumn of 1934, and again
in the autumn of 1935. Four consecutive groups of annual records were
thus provided. In addition to indicating the distribution and abundance of
short-tailed shrews and white-footed mice, these operations revealed the

46 THE CLEVELAND Museum OF NATURAL HISTORY ae

presence of certain other species of small mammals—namely, Hudson Bay
jumping mouse, woodland jumping mouse, pine mouse, meadow mouse,
smoky shrew, and star-nosed mole. The results of the quadrat trapping are
given in Table 12.

TABLE 12. Trapping records of mice and shrews.

Quadratsacn ee eee A-beech- B-beech- | C-beech- D-beech- E-beech-
maple hemlock maple hemlock maple Totals

?35|| ?32! ?33) ’34) 735)) 32) 733

— SS

Nearss since s> 2s pe 1°32 733) ?34)?35/ 32)? 3)°34 735}| 32) 33) ?34

pati

3
Short-tailed shrew...... OS 2 SH OO 2 Sas a ae as
White-footed mouse....|| 8 | 1] 0 | 3 OVO Se GuOs Ot aa Slesal taney,
Hudson Bay jumping

INIGUSE), |Aeaeoie ie aie ois 2 Bacon Sell ate A etelllestlorerllicera eeeretle
1 FEO AS} AE aR hy Se eh eel ee re ot Peete tee ea | Bp a Syl eac esas ales c
Meadowsmouses ss -- all cs | eal een eer Reslioee 1 |i AV exeill oretelltece tell ore eal eee ee
SMOKWISHEeWwA corse ae claoe ] Wat al Pee be Me eres SU e Si] Sanus etovattercrelllte nee Seater eee
Wotalst<iisre cists 18 | 513 u 1671 OF) 2 SL Sa Sas 2 eS 2s

By reducing square meters to acres, and averaging the catch of all five
quadrats annually for shrews and mice, an estimate of the numbers of these
animals on an acreage basis may be secured. These figures are shown in
Table 13. For convenience the estimated numbers of the other common
mammals of the area are also shown in this table. These are based, not on
trapping records, but on weekly counts of numbers, studies of tracks on the
snow in winter, and other evidence. The fact that the two species of jump-
ing mice do not appear from the trapping records to be of general distribu-
tion within the area, and the actual limits of their habitats being unknown
at the present time, makes it impossible to include these species in the esti-
mate. The occurrence of the meadow mouse in 1935 is considered not to
represent a resident animal, but rather one migrating through the area. The
four records of the occurrence of the smoky shrew (2 in traps, 1 jaw-
bone found, remains of 1 in an insect trap) at widely separated points, two
of which were in beech-hemlock, and two in beech-maple environment, sug-
gest the general distribution of this animal throughout the area, and esti-
mates of numbers are given. The case of the pine mouse presents an inter-
esting situation. Previous to 1934 there was no evidence of the presence of
this species in the area. The capture of 2 individuals (1 female, 1 immature
male) in one quadrat well within the interior forest (beech-maple) in 1934
indicated small numbers and limited distribution. In 1935, although but 7
captures were recorded in the quadrats (Table 12), 12 others were caught
in various ways (the writer caught one by hand) at such widely separated
points within the area as to make it certain that the species was then well
established in all parts of it.

July, 1936 A BEEcCH-MAPLE CLIMAX COMMUNITY 47

TABLE 13. Common mammal population of the area—numbers of individuals.

Autumn 1932 Autumn 1933 Autumn 1934 Autumn 1935
Species SER Ci ee SN lh aR ed

Per | *Per | Total| Per Per | Total| Per Per | Total} Per Per | Total

i ff fn | | ce | en | a |

Short-tailed shrew... .|299.45] 739.6 |19464.| 97.12] 239.8 | 6312.| 48.56} 119.9 | 3156.|187. 461.8 |12165.
White-footed mouse ../218.52} 539.7 |14203.| 40.46) 99.9 | 2629.| 32.37] 79.9 | 2104.|209.8 | 518.1 |13635.

See SEAT AUS SCPE Vet oh fener ake Ile eis oye evlevay chev ll levaioveite ail Siew fauaniay sil dneuenaiions 8.1 19.8 525.| 24.2 59.7 | 1575.
tupmunk..........- 10.0 | 24.7 | 650.) 4.0 919) 2602) 10.0 | 24.7 1, ‘650: 1520)| °37-. 04. 9752
SELES? SEDINSIIZ’g 0.6 omic VERO) EIS ec (NERA eee) (UI Ue ore | eRe 8.1 19.8 525.| 4.0 9.8 260.
Gray squirrel........ 0.03 0.07 2a ORs 0.74; 20.) 0.9 1h, sf) 60.| 1.0 2.4 65.
Red squirrel......... 0.31 0.74; 20.) 0.23 ON5i7 15 ¥3| "Olas 0.74 205 025 132 30.
Cottontail rabbit..... 0.46 1.14; 30.| 0.61 1.48} 40.) 0.03 0.07 Dele O206l)) O15 4,
PURE RDUSERELITECIOM PO” leis) < ore coi] (a cos ace arsil is larokeeoall We Glee allele aes ete wiatniels 0.37 0.91 24 \O.37 0.91 24.
MWoodchuck.......... 0.15 0.37 10.| 0.06} 0.14 4.1 0.09} 0.22 6.| 0.06}; 0.15 4,
MEACCOON's cieisicisieisiee 6 0.18} 0.45 IZE NOS US Oe Siz, 10.} 0.18} 0.45 12.| 0.18) 0.45 12
CROUCH eee ee 0.03 0.07 2.| 0.06) 0.14 4.1 0.03 0.07 DA O03 0.07 Qi
Sire 0.09} 0.22 6.| 0.09} 0.22 6.| 0.00} 0.00 0.; 0.00; 0.00 0
BECO KI 2 ale heisco 26 0.03 0.07 2.!| 0.06} 0.14 4.! 0.01 0.03 1 0.03 0,07 2

Pm EAISIDET ACTS. 4... (529229. .0066-laceoes 11 Sees (CS ean tee afer AOS BOS ie ecclesia BAD DSI 5 Beva.e ail esetaevete

er Heetares:cis <=|incs ars 6 IB OZB13 eee elie isee S55 40 le ea eee Assi laeuasell¢ocacc 1091-80). 22.--

Mosralunmianedawe yer || 5 Aelia esotsvers« SAA OT ee ore ea 93 OA ee ees ee LOST lara tet onl eater 28753

*] hectare = 2.47 acres.

The status of the moles and the bats in the area is not clear. The sub-
soil is ill-suited to the work of moles because of its hardness, and though
earthworms are noted in the humus and in the soft wood of decaying logs,
the tunnels of moles are rarely evident. Perhaps the loose leaf-litter may
effectually conceal them. On the other hand, when the humus was reduced
to the semblance of tinder during the dry spring and summer of 1933 and
mole tunnels were for the first time noted in the drying stream-beds, they
were few in number. For the present the writer assumes that the numbers
of moles of all species in the area are quite limited. But two specimens have
been taken, representing two species.

The bats are as elusive as the moles. Bats have never been noted in
numbers, and only on the wing. They give the impression of passing over
or through the area rather than of hunting within or over it. They are
usually seen flying high, though Mr. Earl Cady reports having seen two large
bats (big brown bats?) at 12:30 a.m. September 7, 1933, apparently busily
feeding in the moonlight over a large patch of jewel-weed in the woods. In
the latter part of August 1933 an attempt was made to determine at least
the species of bats flying in the forest. Mr. Arthur B. Fuller of the Cleve-
land Museum of Natural History, on three different nights, by wing-shooting
over a grape tangle in the beech-maple association, collected a total of 5
bats, of which 3 were big brown bats. Apparently this species is the com-
mon bat of the area.

48 THE CLEVELAND Museum oF NaTurRAL History See

Foop CHAINS AND EcoLtocicaL NICHES

In summing up the relative importance of the mammals of the area
account must be taken not only of their numbers, but also of the duration
of the periods of their activity, and of their food-habits. Those mammals
classed as the less common species (Table 11) are clearly of much less
importance ecologically than are the common ones. If they were entirely
removed from the area the probability is that little if any change would
be apparent. Attention may therefore be centred upon the common species.
Table 14 classifies these on the basis of duration of activities.

TABLE 14, Common mammals classified according to duration of activities.

Active through- Active by Active by Inactive during

out the year day night winter
Short-tailed shrew...... ¥ * SMM) occ
White-footed mouse... . Se) os Mt Ea ale tan pam coe ey
Chipmunks eee aes Me ee * eae ig
Gray squirrel) 20402. - MOE TRUM i -
Red squisreliynn i. i Bo ps ee
Flying squirrel......... Dede ec elaaiceh peegies EO eee
Cottontail rabbit....... . a Fl) ad
Woodelnutles 2). keh hr iahons : NG i
RACCOMMY see oer CM ick Guts il Cah fy Nua Mian is *
SCT T Ts BE EEE FNAL Fane abe ane I A PT a hea + if
Opossmanrets 2\/ Nee Aide dd i due Awd Da ah Cail deck § * ss
OKA) SPE A ew asia Madan * - =

eceree

Probably the most ceaselessly active of these animals is the short-tailed
shrew, though Shull (1907), who studied the habits of this mammal, ex-
presses the opinion that “times of daylight are not selected by the shrew for
its greatest activity.” Yet the writer’s observations do indicate considerable
daylight activity for this little mammal. In the area under study the barred
owl is a consistent hunter of the shrew by daylight. One can often locate
shrews at work by the rustling movement of dry leaves on the forest floor
by day as well as by night. Not infrequently one gets a glimpse of a shrew
by day as he flashes from one opening of his tunnel to another, or he may
sometimes be surprised at work by quickly removing or turning over the de-
cayed log or piece of bark that serves as a roof for his runway. Traps set
in the morning and inspected before dark frequently contain shrews. Some-
times the bait will be so quickly taken by shrews, after setting the trap in
daylight, that the operator hears the snap as he turns away. That shrews
are active at all seasons of the year is indicated by their tunnels under the
snow, and their trails on its surface in winter.

Although the shrew is usually referred to as an insectivore, ecologically
he might just as well be classed as a carnivore, for he is a hunter after fresh
meat in any form, and in proportion to his size he needs a great deal of it.
Shull (1907), studying the short-tailed shrew in a swampy habitat near

July, 1936 A BEECH-MAPLE CLIMAX COMMUNITY 49

Ann Arbor, Michigan, found that in winter snails formed a part of the food
supply. Meadow voles (Microtus) were also an observed part of the diet.
It was found that vegetable foods offered to captive shrews were invariably
rejected.

On the basis of experiments with captive shrews, Shull estimated that
one short-tailed shrew, in one month, will eat:

Per cent

Number of total
Preoew mice Of equivalent if MICE ....6.s600ssesc0scensoes 8 40
Adult insects (size of May beetles Lachnosterna) .......... 90 20
Insect larvae (size of May beetles —Lachnosterna) .......... 78 20
matmwenms 4 cm. long, contracted 2.2.66. ccceces ccs csecbas 53 5
SITES S. cecld Qt cea eye et sie IM SACU RS Sie TG glee arnt Aa Oe Rl 18 15

In a different habitat the relative availability of the different items in the
diet would certainly influence the proportions consumed. At North Chagrin
undoubtedly the proportion of mice eaten would run higher both in number
and per cent of total, as Peromyscus is smaller than Microtus, and the supply
of snails would be considerably less. It is also probable that the proportion
of insects, millipeds, and the like would run higher. Smaller shrews, like
Sorex, would also be preyed upon. It is important to recognize the short-
tailed shrew as more than an eater of insects.

Occupying the position of the most abundant mammal in the area, being
the only one that approaches constant activity by day and by night, and at all
seasons of the year, requiring an enormous amount of animal food at all
times, and having no real check upon numbers except the barred owl, the
short-tailed shrew appears as probably the most influential mammal in the
area. He acts as an efficient check upon the numbers of mice and other spe-
cies of shrew, and takes out of the humus and decaying logs and stumps an
immense number of insects and their larvae and of other forms like millipeds,
centipedes, sowbugs, and worms. It is not entirely fanciful to liken his
network of under-cover tunnels and runways to a vast system of spider-
webs, laid down for the same purpose as the spider’s web—the ensnaring of
his prey.

From the standpoint of numbers and all-year-round activity the white-
footed mouse probably ranks second in importance in the area. Compared
with the shrew, the white-footed mouse does not exhibit the same kind of
high-tension activity. Johnson (1926) found experimentally that forest
deer mice (Peromyscus) were nocturnal, with a well marked rhythm of ac-
tivity, sinking to a minimum during daylight hours and reaching a high
degree normally during the hours of darkness. Unlike the shrew, the mouse
is directly dependent upon plant products for his main support. Although
a rodent, he is not a strict vegetarian, however, but consumes considerable
animal material. All of the captive white-footed mice observed by the

50 THE CLEVELAND Museum oF NaTturAL History Bet

writer have always eagerly accepted insect food. Snails also are probably
eaten (Cahn and Kemp, 1929).

Checks upon undue increase in numbers of mice exist in the short-tailed
shrew, as noted above; the barred owl, whose cast pellets found in the area
frequently contain remains of Peromyscus; and in the larger mammals of
the flesh-eating group—skunk, raccoon, opossum, weasel, and fox.

The chipmunk should undoubtedly be placed third in importance among
the mammals of the area on the basis of number and general distribution,
even though he withdraws from above-ground activities at certain seasons
of the year. While popularly credited with being a complete hibernator
(Anthony, 1928, p. 243), this is certainly not the case with the chipmunks
in the area under study. Except for the winter 1932-33, when the chipmunk
population at North Chagrin was reduced to a very low ebb, the writer has
observed chipmunks abroad throughout the winter months, sometimes with
the temperature as low as 10° F. (-12.2° C.), and has noted their tracks in
the snow indicating great activity at certain times in winter. Counts of as
many as 58 in one morning, and 63 in another, both in February, suggest
anything but complete hibernation at that time. In fact the writer is of the
opinion that the entire chipmunk population was aroused to a high pitch of
excitement by mating activities at that particular time.

The periods of the chipmunk’s greatest activity at North Chagrin are
from the first week in May to the middle of July, and from the middle of
September to late November if the weather is good. There is a period of
retirement underground from mid-July through August which is probably
correlated with the physiological condition of moulting and renewing of the
pelage. Howell (1929) mentions the fact that out of 1,349 specimens of
Tamias examined by him, very few moulting specimens have been found.
This is no doubt due to the animal’s disappearance during the period of
moult, so that relatively few moulting specimens would be encountered by
collectors. Schooley (1934) thinks this disappearance, reported by others
but not observed by him, is due to the summer breeding season.

The chipmunk, like the mouse, is dependent mainly on vegetable matter
for his food supplies but also takes animal matter (Howell 1929, Cahn and
Kemp 1929, Seton 1909). Captive chipmunks observed by the writer ate
with great avidity all insects offered, and shells of snails are commonly
found among the refuse on their feeding tables. In May and June the chip-
munks at North Chagrin do a great deal of “rooting” in the humus after
such food as the tubers of spring beauty, dwarf ginseng, Indian cucumber,
and squirrel corn, or the root-stocks of trillium. In the fall, beech nuts,
sugar maple seeds, and other nuts and seeds are gathered and stored under-
ground.

Checks on the numbers of chipmunks in the form of larger predators

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 51

are not very apparent. It is possible that the fox and the weasel may exer-
cise some influence, but direct evidence is lacking. Chipmunk remains have
not been found in the casts of the barred owl in the area, nor has the owl
been observed to hunt chipmunks. Cats have been definitely observed stalk-
ing chipmunks. Possibly the pilot blacksnake may be a definite consumer
of chipmunks in summer. Under favorable conditions of food supply there
seems to be no reason why the chipmunk population should not occupy all
available habitats in the area—and this indeed seems frequently to be realized.
Competition would then act to prevent overpopulation.

The other squirrels—red squirrel, gray squirrel, and flying squirrel—are
all consumers of nuts, seeds, and fruits, as well as of some animal matter.
Captive flying squirrels and captive red squirrels, under the observation of
the writer greedily ate all insects offered them. As a group the arboreal
squirrels are important members of the community by reason of their al-
most continuous activity throughout the year and their steady consumption
of basic forest food supplies. Their function as destroyers of large num-
bers of insects must not be overlooked. Competition between species and
individuals apparently acts as an efficient check upon numbers.

The rabbit and the woodchuck are normally rather unimportant elements
in the biota of the area because of their small numbers. If either should
increase greatly in abundance, and maintain their increased numbers for any
considerable period of time, they might have a significant relation to the
vegetation of the area by reason of their food requirements. The rabbit
especially, under such conditions, might affect greatly the character of for-
est seedling trees and saplings. Such a condition has apparently never oc-
curred, however. The very apparent check upon both of these animals is
the red fox, about whose dens the remains of woodchucks and rabbits are
very commonly found. Hamilton (1935) mentions rabbits as constituting
22.1 per cent by bulk, of the food of 206 foxes in fall and winter in New
York and New England, and woodchuck remains stand highest in the list
for 31 fox dens examined by him in July and August.

With the exception of the short-tailed shrew, the carnivores of the area
have a larger sphere of activity than the 65 acres under study. Yet their
regular visitation of it, and their resident character to some extent in the
case of certain individuals, means a very considerable influence in its biotic
relationships. The raccoon, the skunk, and the opossum may be regarded as
somewhat in the nature of additional checks upon the undue increase of the
smaller mammals. They undoubtedly limit to some extent the numbers of
birds nesting on or near the ground. They must also be recognized as large
consumers of insects, and of the so-called ‘“‘cold-blooded” animals—cray-
fish, frogs, salamanders, and snakes. Their periods of greatest activity

52 THE CLEVELAND MuseuM oF NATURAL HIstTorRY Sct eee

correspond with those of the “cold-blooded” animals, and raccoons are espe-
cially diligent hunters of this sort of fare.

The weasel and the fox provide still further checks upon the smaller
mammal population, and the fox especially seems important in limiting the
number of rabbits.

Taken as a group, the mammals of the area illustrate well the adapta-
tions of animals to a forest environment. Omitting the dog and the cat,
which are associated with the presence of man in the near vicinity, and the
deer, which is an occasional visitor only, and the meadow mouse, which we
may consider a transient visitor, it appears that the 23 species remaining
consist of 5 squirrels, 4 mice, 1 rabbit, 1 woodchuck (all chiefly herbivores) ;
2 shrews, 2 moles, 3 bats (all chiefly insectivores) ; and the raccoon, opos-
sum, skunk, weasel, and fox (all chiefly carnivores). The composition of
the whole group then, may be roughly indicated as:

Herbivores, 48 per cent.

Insectivores, 30 per cent.

Carnivores, 22 per cent.

This arrangement, however, is only a species grouping and does not indi-
cate food relationships with any degree of exactness. Probably the weasel
is the most nearly strictly carnivorous animal on the list, and the rabbit and
the woodchuck the most nearly strictly herbivorous ones. Undoubtedly the
squirrels and the mice consume great quantities of insects along with their
mainly herbivorous diet, and this is true also of most of the carnivores.
Even the red fox is accredited as an insect eater (Dearborn, 1932, and Ham-
ilton, 1935). The bats, no doubt, are strictly insectivorous, but the moles
and shrews are carnivorous as well as insectivorous. Most of those classed
as carnivores might also be classed as omnivores. But the gist of the mat-
ter is that plant products, insects, and other invertebrates, are the mainstay
of the mammal population of the area, while to a more limited extent the
smaller mammals themselves serve to support the larger ones.

In their occupation of the territory it is interesting to see how these
mammals have occupied fully all available habitats. The moles occupy the
deeper parts of the substratum, so far as it is available to them; the shrews
have appropriated the loose humus and leaf litter of the forest floor, using
the runways of mice and moles as well; the chipmunks are animals of the
floor itself and the débris that lies upon it in the shape of old logs, stumps,
and litter, though making their homes and storehouses in tunnels that reach
into the subsoil itself; the mice are inhabitants of logs and stumps and hol-
low trees and other forest litter, and the white-footed mouse is a climber
of trees as well; the red squirrel, with his headquarters usually under some
stump or bunch of roots, also ascends the trees, and frequently builds a nest
in a grapevine suspended aloft; the gray squirrel is the true arboreal animal

July, 1936 A BeecH-MapiLe CLimax CoMMUNITY 53

of the area, spending much time aloft, using aerial runways by preference,
and having his winter quarters usually high above the ground in some hol-
low tree top; the flying squirrel is also an arboreal animal, extending his
aerial highways beyond the limits of those of the gray squirrel by reason
of his abilities as an aerial glider; and the bats complete the occupation of
all available habitats by hunting through the air itself.

The larger mammals of the list are mainly hunters upon the surface of
the ground, though the raccoon and the opossum are climbers, and the rac-
coon’s winter quarters are usually high above ground.

This division of territory and diversity of diet makes possible the sup-
port of a large population of mammals adapted to the limitations of the hab-
itat, provided basic food supplies are present in normal quantities. In this
particular forest this means beech nuts, sugar maple seeds, herbaceous vege-
tation, insects and other invertebrates.

Such was the condition in the autumn of 1931. At that time apparently
every available habitat within the area was occupied to its upper limit of
capacity by the shrews, mice, chipmunks, and gray squirrels. There had
been very large yields of beech nuts and sugar maple seeds the previous
autumn, as well as this autmun. Food supplies were more than adequate
for even the large population then occupying the territory.

FLUCTUATIONS IN NuMBERS OF MAMMALS

As Elton (1927) has pointed out, the chief cause of fluctuation in ani-
mal numbers is the unstability of the environment. This is well illustrated
in the case of the area under study by what happened in the autumn of 1932.
This was the time of almost complete failure of the beeches and sugar
maples to produce seed. Whether the resting rhythm of these two trees
normally coincides, or whether it does so only occasionally because of a
difference in length of rhythm, remains for further studies to determine.
At any rate, basic food supplies practically disappeared just before the win-
ter of 1932-33.

There was little storage of food by chipmunks that autumn, and they
went underground almost a month earlier than the previous year when
storage activities ran well into the last of November. Although there was
no observation of the activities of the white-footed mice, the absence of
their accustomed food supplies would have produced more or less of the
same condition with them, so far as storage of winter food was concerned.
The red squirrels, as appeared later, gathered and stored large quantities
of tulip seed cones, and some of them subsisted upon scarcely anything else
during the entire winter, as indicated by the refuse about their middens as
the winter progressed. Hemlock seeds were also used by the red squirrels,
but there was a deficiency in yield of these seeds also. Mushrooms were

54 THE CLEVELAND Museum oF NATURAL HisToRY ae fs

much used. Seeds of cucumber trees, usually shunned as articles of diet,
were freely gathered, stored and eaten by red squirrels that winter. These
animals are probably naturally resourceful in the discovery and use of
foods outside the usual list, as the droppings of horses were twice noted
in red squirrel middens. These must have been discovered and brought in
from near-by bridle paths. The fact that the red squirrels did not occupy
the territory as fully as did the other rodents was also in their favor, for
it is a recognized fact that competition within the ranks of a species is al-
ways keener than between different species, as the needs of the individuals
are then identical. But the red squirrels were able to and did expand their
individual territories, spreading into parts of the area not previously oc-
cupied by them.

The gray squirrels left the area early. About 50 of these animals oc-
cupied the area the previous winter, producing enough young in spring to
keep their numbers fairly constant. But in September they moved out,
leaving one lone squirrel to face the famine alone. This individual was
frequently noted during the winter following. He seemed to be subsisting
on a few hickory nuts, red oak acorns, tulip seeds, and mushrooms. The
writer even saw him sampling the hard woody bracket of Polyporus ap-
planatus, and later noted that the marks of squirrels’ teeth on these un-
palatable fungi were not at all uncommon that winter.

An interesting fact in connection with this winter was the increase in
numbers of cottontail rabbits within the area. Previously they had been
noted about the edges of the forest. Now they extended their feeding
grounds into all parts of the area. Numbers were probably doubled, in-
creasing from 20 to 40, and there was much evidence of their activities in
the “barking” of young trees, and nipping off of the terminal buds and twigs
of thousands of small trees of beech, sugar maple, and red maple. This
meant the destruction of many seedlings, but of course in most cases they
would necessarily have been eliminated by competition later. The rabbits
naturally were not affected by the failure of beech nuts and sugar maple
seeds, as their food consists of bark, buds, twigs, and the green leaves of
the ferns, Carex, and other woodland plants such as Hepatica and Dentaria
diphylla whose leaves remain green all winter.

During this winter not a single chipmunk was seen above ground, where
counts of as high as 58 in a morning had been made the previous winter
and have been made since. The following spring it was apparent that very
few chipmunks had survived the winter, as only a few individuals were
noted where usually the woods should have been “alive” with them.

The situation with regard to mice and shrews was not fully realized un-
til the following autumn (1933) when the second attempt to estimate num-
bers by trapping was made. Then it appeared that the mice had suffered

July, 1936 A BrEEcH-MAPLE CLIMAX COMMUNITY 55

a decrease of over 80 per cent, and the shrews a decrease of over 65 per
cent (Table 15). The reduction in numbers of mice must have reacted
directly upon the numbers of shrews, as mice enter so largely into shrew diet.

The summer of 1933 proved to be an especially dry one. The months
of June, July, and August were devoid of any effective rainfall (Fig. 5).
Such precipitation as did occur came in the shape of more or less violent
rainstorms, with rapid run-off of water, and quick drying out of the surface
leaves on the forest floor, which afforded no relief to the very dry con-
dition of the humus. The Amphibia, Mollusca, and soft-bodied insects and
larvae either perished or went into aestivation. This again meant a shorten-
ing of food supplies for the shrews. The mice apparently suffered more
than the shrews as indicated by the shift in relative numbers of the two
species (Table 15). Not only was their accustomed winter food supply lack-
ing, but the shrews, on shortened rations, due to the disappearance of the
insects and other invertebrateas, must have turned to the mice as acceptable
food with more persistence than usual.

TABLE 15, Decrease in numbers of mice and shrews.

1932 1933 1934 1935

Total numbers (5 quadrats):

SHont-tatled shrew, jails. a.) 4 se, «eee 37 12 6 23

Wihttestooted mouse). Jc... 254... 28 5 4 27
Relative proportions (percentage of shrews to mice):

Shortstailea SMrewi ls s\c\e cic e's sa eet ss 58 70.6 60 46

White-footed mouse.............. 42 29.4 40 54
Per cent of decrease as compared with 1932:

Shost=tatled shrewi. jes es eee sate 67.6 83.8 Sve 5

Wihtte-footed amouse!,.. 3.06.62 0. 5. 81.4 85.2 4.0

With the short-tailed shrew present in the numbers indicated in the
autumn of 1932 (Table 13), one has only to attempt to visualize the enor-
mous amount of animal food necessary for its support to sense the shrew
population collapsing under its own weight. This explains the avidity with
which baits were taken that autumn; the speedy devouring of so many of
the animals trapped; the extension of runways into almost every square
foot of ground; the absence in the traps of any other species of shrew. So
far as the writer’s observation goes, the only real check upon the numbers of
shrews in the area was one pair of barred owls and their two young. All
barred owl pellets thus far found in the area have, without exception, con-
tained skulls or jaws of Blarina brevicauda as well as other material.

If, under optimum conditions, such as apparently existed in 1932, the
shrew population got “out of bounds,” so to speak, in the absence of suffi-
ciently strong checks, then competition within the species itself would auto-

56 THE CLEVELAND Museum oF NaTurRAL History eee

matically operate to reduce numbers. But as has been indicated, other and
even more potent forces were already at work.

Coincident with the increase in the number of rabbits in 1932, there was
an increase in the number of foxes hunting in the area, as shown by tracks
in the snow in the winter of 1932-33. The number of rabbits was estimated
at 40 in January, 1933. On January 15, 1934, with a fine tracking snow
on the ground for several days, it was apparent that only 2 rabbits were
then inhabiting the area. On the other hand the snow showed the presence
of at least 4 hunting foxes—two more than the previous winter. Perhaps
the decimation of the numbers of mice and squirrels which may be looked
upon as “buffer food,” had compelled closer attention to rabbit hunting on
the part of the fox population. It is a recognized fact that there always
seems to be a perceptible lag in the abundance of the carnivore as related to
abundance of food supply (Elton 1927). The record of the snow the fol-
lowing winter (1934-35) showed one fox and no rabbits in the area.

The total disappearance of the skunk following the great reductions in.
numbers of mice, and the drying out of the humus insects in the summer of
1933 is another significant correlation. So also is the reduction in numbers
of the pilot blacksnake. |

The yield of beech nuts was again ample in the autumn of 1933 and of
1934, but the sugar maple did not come into bearing again until 1934. The
first mammal to show recovery in numbers from the disturbed conditions
of 1932 was the chipmunk. There was apparently a small spring brood,
and also a summer brood, in 1933; the usual winter activity and a large
emerging chipmunk population in the spring of 1934. Apparently numbers
were completely recuperated during 1934, and the area seemed to have about
all the chipmunks it would normally support. But 1935 proved this assump-
tion wrong, for numbers were again increased. Incidentally this was true
not only of the area under study, but chipmunks reached abnormally large
numbers throughout the Chagrin valley and elsewhere in the vicinity of
Cleveland. The speedy return of the species to normal numbers in the area
under study is a notable demonstration of rapid response to favorable condi-
tions in the environment. These must have been close to optimum to have
produced such a result.

On the other hand the numbers of shrews and mice continued to drop,
so that in the autumn of 1934 trapping records showed a decrease of over
16 per cent for the shrews and almost 4 per cent for the mice as compared
with 1933. The shrews were now apparently suffering more than the mice,
which would be expected because of the complete restoration of food sup-
plies for the mice but not for the shrews.

The appearance of the pine mouse and the smoky shrew in the traps for
the first time (1934), when the numbers of their arch competitor and prob-

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 57

able deadly enemy the short-tailed shrew was reduced to a comparatively
low figure, seems to indicate that these animals may prosper only when the
numbers of the short-tailed shrew are relatively small. Possibly their curve
of abundance may fluctuate inversely with that of the short-tailed shrew.

The year 1935 proved to be a “mouse year” at North Chagrin. It wit-
nessed the return of the white-footed mouse to numbers within 4 per cent
of the high figures of 1932. The short-tailed shrew showed a substantial
increase in numbers over 1934, but was still 37.5 per cent below 1932 num-
bers. This shift in relative proportions (Table 15) made the white-footed
mouse, for the first time during the four years of this study, the most abun-
dant mammal of the area. A new mammal, the pine mouse, appearing first
in 1934, became common in the area. As evidence of the pressure of num-
bers of mice outside the area, the meadow mouse, not normally found in the
forest, appears far within the forest boundaries.

Although the foregoing discussion of fluctuations in numbers of mam-
mals is far from complete, yet enough evidence seems to have come to the
surface to show how far-reaching a disturbance of the so-called “balance”
of nature may be. In this case the disturbance is partly the normal rest in
the bearing rhythm of the forest dominants, and partly the abnormal break
in the climatic factor of precipitation of moisture. Only in the case of the
skunk is there any direct evidence of disease having been a factor in the
situation. Competition between individuals and between species seems to
have been largely the keen-edged instrument whereby numbers were cut
down after the failure of basic food supplies.

THE BIRDS OF THE AREA

As contrasted with the mammals, the birds of the area constitute at
times a very rapidly shifting element in the community. From the stand-
point of time spent within the area the birds may be divided into the
following groups. Scientific names and the order of listing are as given
in the American Ornithologists’ Union Check List of North American
Birds, Fourth Edition, 1931.

TasLe 16. Birds of the area by seasonal groups.
1, Permanent residents

(Species found in the area throughout the year)

Eastern Ruffed Grouse Bonasa umbellus umbellus (Linnaeus).
Northern Barred Owl Strix varia varia Barton.

Northern Pileated Woodpecker Ceophloeus pileatus abieticola Bangs.
Red-bellied Woodpecker Centurus carolinus (Linnaeus).

Eastern Hairy Woodpecker Dryobates villosus villosus (Linnaeus).
Northern Downy Woodpecker Dryobates pubescens medianus (Swainson).
Blacked-capped Chickadee Penthestes atricapillus atricapillus (Linnaeus).
Tufted Titmouse Baeolophus bicolor (Linnaeus).
White-breasted Nuthatch . Sitta carolinensis carolinensis Latham.

Eastern Cardinal Richmondena cardinalis cardinalis (Linnaeus).

Red-eyed Towbee Pipilo erythrophthalamus erythrophthalamus (Linnaeus).

58 THE CLEVELAND Museum oF NaTuRAL History Se Pee

2. Autumn and winter visitors

(Species found more or less continuously in the area only in the autumn and winter months)

Northern Blue Jay
Red-breasted Nuthatch
Brown Creeper
Winter Wren
Carolina Wren

Eastern Golden-crowned Kinglet

Eastern Goldfinch
Slate-colored Junco

Cyanocitta cristata cristata (Linnaeus).

Sitta canadensis Linnaeus.

Certhia familiaris americana Bonaparte.

Nannus hiemalis hiemalis (Vieillot).
Thryothorus ludovicianus ludovicianus (Latham).
Regulus satrapa satrapa Lichtenstein.

Spinus tristis tristis (Linnaeus).

Tunco hyemalis hyemalis (Linnaeus).

3. Summer residents

(Species found continuously in the area only during spring and summer)

Northern Crested Flycatcher
Eastern Phoebe

Acadian Flycatcher

Eastern Wood Pewee
Eastern Robin

Wood Thrush
Yellow-throated Vireo
Red-eyed Vireo
Black-throated Green Warbler
Cerulean Warbler

Oven-bird

Louisiana Water Thrush
Hooded Warbler

American Redstart

Scarlet Tanager
Rose-breasted Grosbeak

Myiarchus crinitus boreus Bangs.
Sayornis phoebe (Latham).
Empidonax virescens (Vieillot).
Mvyiochanes virens (Linnaeus).
Turdus migratorius migratorius Linnaeus.
Hylocichla mustelina (Gmelin).
Vireo flavifrons Vieillot.

Vireo olivacea (Linnaeus).
Dendroica virens (Gmelin).
Dendroica cerulea (Wilson).

Seiurus aurocapillus (Linnaeus).
Seiurus motacilla (Vieillot).
Wilsonia citrina (Boddaert).
Setophaga ruticilla (Linnaeus).
Piranga erythromelas Vieillot.
Hedymeles ludovicianus (Linnaeus).

4. Transients

(Species found in the area only during their spring or autumn migration)

Yellow-bellied Sapsucker
Yellow-bellied Flycatcher
Eastern Hermit Thrush
Olive-backed Thrush
Gray-cheeked Thrush
Wilson’s Thrush

Eastern Ruby-crowned Kinglet
Blue-headed Vireo

Black and White Warbler
Blue-winged Warbler
Nashville Warbler
Magnolia Warbler
Black-throated Blue Warbler
Myrtle Warbler
Blackburnian Warbler
Chestnut-sided Warbler
Bay-breasted Warbler
Blackpoll Warbler
Connecticut Warbler
Canada Warbler

Eastern Purple Finch
White-throated Sparrow
Eastern Fox Sparrow

Saphyrapicus varius varius (Linnaeus).
Empidonax flaviventris (Baird and Baird).
Hvylocichla guttata faxoni Banga and Penard.
Hylocichla ustulata swainsont (Tschudi).
Hylocichla aliciae aliciae (Baird).
Hylocichla fuscescens fuscescens (Stephens).
Corythylio calendula calendula Baird.

Vireo solitarius solitarius (Wilson).
Mniotilta varia (Linnaeus).

Vermivora pinus (Linnaeus).

Vermivora ruficapilla ruficapilla (Wilson).
Dendroica magnolia (Wilson).

Dendroica caerulescens caerulescens (Gmelin).
Dendroica coronata (Linnaeus).

Dendroica fusca (Miller).

Dendroica pennsylvanica (Linnaeus).
Dendroica castanea (Wilson).

Dendroica striata (Forster).

Oporornis agilis (Wilson).

Wilsonia canadensis (Linnaeus).
Carpodacus purpureus purpureus (Gmelin).
Zonotrichia albicollis (Gmelin).

Passerella tliaca iliaca (Merrem),

5. Occasional visitors

(Species noted only occasionally in the area)

Turkey Vulture
Sharp-shinned Hawk
Cooper’s Hawk

Cathartes aura septentrionalis Wied.
Accipiter velox velox (Wilson).
Accipiter cooperi (Bonaparte).

July, 1936 A BrecH-MapLe CLimax CoMMUNITY 59

Eastern Red-tailed Hawk
Broad-winged Hawk
Eastern Bob-white
American Woodcock
Eastern Mourning Dove
Yellow-billed Cuckoo
Great Horned Owl
Eastern Whip-poor-will
Eastern Nighthawk
Chimney Swift
Ruby-throated Hummingbird
Northern Flicker
Purple Martin

Eastern Crow

Starling

Bronzed Grackle
Eastern Cowbird
Canadian Pine Grosbeak
Eastern Blue Grosbeak
Indigo Bunting
Common Redpoll

Red Crossbill

Buteo borealis borealis (Gmelin).

Buteo platypterus platypterus (Vieillot).
Colinus virginianus virginianus (Linnaeus).
Philohela minor (Gmelin).

Zenaidura macroura carolinensis (Linnaeus).
Coccoyzus americanus americanus (Linnaeus).
Bubo virgimanus virginianus (Gmelin).
Antrostomus vociferus vociferus (Wilson).
Chordetles minor minor (Forster).

Chaetura pelagica (Linnaeus).

Archilochus colubris (Linnaeus).

Colattes auratus luteus Bangs.

Progne subts subts (Linnaeus).

Corvus brachyrhynchos brachyrhynchos Brehm,
Sturnus vulgaris vulgaris (Linnaeus).
Quiscalus quiscala aeneus Ridgway.

Molothrus ater ater (Boddaert).

Pinicola enucleator leucura (Miiller).

Guiraca caerulea caerulea (Linnaeus), \
Passerina cyanea (Linnaeus).

Acanthis linaria linaria (Linnaeus).

Loxia curvirostra pusilla Gloger.

The fact that the blue jay and the Carolina wren are included in the

above list as autumn and winter visitors, rather than as permanent residents,
may seem strange to one familiar with the birds of the Cleveland region,
yet from the standpoint of the forest areas under study this is their status.
The record of the blue grosbeak is unusual— a single record of a pair ob-
served by the writer under favorable conditions May 15, 1933, in one of
the grape tangles of the area.

DIsTRIBUTION AND ABUNDANCE OF Birps

Those birds nesting in the beech-hemlock environment only were the
black-throated green warbler and probably the ruffed grouse. Those nesting
in both beech-maple and beech-hemlock were the wood pewee, wood thrush,
and ovenbird. The other species on the lists of permanent and summer
residents nested exclusively in the beech-maple association. Most of the
transient species were observed in beech-maple environment, while the winter
bird companies roamed about the whole area.

The transient species, with the exception of the robins, thrushes, and
certain warblers, do not bulk large in numbers. Estimates of 500 robins,
200 thrushes, and 300 warblers have been made at certain times. Autumn
and winter visitors are irregularly present except in the case of the slate-
colored junco and red-breasted nuthatch. Flocks of from 50 to 60 juncos
have been noted, and the red-breasted nuthatch, present in alternate years,
sometimes totals 50 to 60 in number.

The permanent resident species became quite well known. The number
of hairy and downy woodpeckers, chickadees, tufted titmice, and white-
breasted nuthatches are augmented considerably at times during the winter.
Whether or not the actual birds nesting in the area in summer are present
also in winter is not definitely known. Butts (1930) determined by band-

60 THE CLEVELAND Museum oF NATURAL HISTORY "oe ce

ing methods that individual chickadees, banded in winter, nested in or quite
near their winter feeding territory, and that individual white-breasted
nuthatches nested within or very close to their winter feeding area.

The barred owl, the pileated woodpecker, the ruffed grouse, and the
cardinal are not usually present in greater numbers in winter than in summer.
The towhees congregate in the woods in winter, but in spring most of them
leave the area. These probably constitute the towhees nesting just out-
side the forest, though usually a pair or so may be found nesting just inside
the forest edge.

Careful records of the numbers of birds observed on the weekly sur-
veys of the area have been kept over the entire period of this study. The
observed occurrence of the bird has been located on a map of the area car-
ried each week for the purpose. Thus the species-constitution, numbers, and
territories of the winter bird companies have been determined, the distribu-
tion of species and individuals noted, and summer nesting territories charted.
While these figures (on their face) reflect seasonal fluctuations, they
need considerable interpretation when it comes to studying absolute abun-
dance. Weather conditions influence the count greatly at times. High
winds, and storms of snow or rain reduce the number of birds observed.
The appearance of the foliage on the forest trees in May is comparable to
the dropping of a heavy curtain so far as visibility is concerned. Then
sight records are largely replaced by those of hearing. When the song period
is over it is quite difficult at times to get evidence of the presence or absence
of birds. Chickadees, titmice, nuthatches, and woodpeckers become furtive
and inconspicuous at the approach of, and during the nesting season. Dif-
ferences in weekly counts at times reflect changes in activities or behaviour
rather than fluctuations in abundance.

Perhaps the most reliable index to abundance of birds is the record of
nesting pairs. By the use of the weekly maps, described above, it is possible
to build up a series of maps (one for each species) covering the nesting
season, which will show concentrations of records about certain localities.
The localities thus indicated may be considered as within the territories of
breeding pairs, and it is thus possible to estimate the numbers of breeding
pairs of birds throughout the entire area and the approximate extent of
the territory occupied by each. Figure 14 is presented as an illustration of
this method, the species chosen being the hooded warbler, one of the com-
mon nesting species of the area. As nests are actually found, even though
it may be during the following winter, their location with reference to the
recorded location of the individual birds on the map makes it appear that
this method may be relied upon to reveal the presence of a nesting pair or
lone male, and fix the approximate limits of the nesting territory.

July, 1936 A BrecH-MapLe CLimMax CoMMUNITY 61

APPROXIMATE LOCATION OF
NESTING TERRITORIES OF
16 PAIRS OF HOODED
WARBLERS 1934

Sm SVD SR RES aN TRE RAYAERU TE VY MIE BUND HY SS OTSA NE HS URI UAT SATE CER SS SE SBE

Fic. 14. Approximate nesting territories of hooded warblers in the area under
study in 1934, on the basis of records made throughout the nesting season. First,
second, and third nests of the same pair are numbered.

Schiermann (1930), studying the density of population of breeding birds
in a forest in Brandenburg, Germany, adopted the method of laying out
quadrats 250 meters (820.1 feet) square, and then searching systematically
for every nest within the quadrat. From these sample quadrats the num-

62 THE CLEVELAND Museum OF NATURAL HISTORY po

ber of nesting pairs of birds in the whole area was then estimated. Schier-
mann found that his statistical results obtained from the quadrat agreed
closely with figures arrived at from frequent visits to the area over a
period of six years. He concludes, however, that his quadrats are of help
only in conjunction with an intimate knowledge of the area obtained from
long contact with it. With this conclusion the experience of the writer
agrees.

The complete record of nesting birds in the area under study, as deter-
mined by the method of charting observed occurrences of the birds on a
map, for the summers of 1932, 1933, 1934, and 1935 is shown in Table 17.
Second and third attempts at nesting are not counted in this tabulation, but
only the number of pairs of birds.

Tas_Le 17. Numbers of nesting pairs of birds.

Numbers of Pairs

Species S| S|

1932 1933 1934 1935

I? WRed=evyed: Vireo. 2a pr, Delle oe ae Ye 25 36 35 30

DR ENVapaeltisiy)) ce Coke ea eee we cht alae 17 25 22 14

aP PHOOUEG NWiarblets <> sey iis) aad diners Be 15 15 16 9

a cAmerican dRedstares 2)..5 02 on. aidike bees we 12 17 19 19

Oven pita hohe as. ake tel eas eet i 18 16

Gow WiteG RL IEMNOUSE acy se ool ce hes eee

de eBlack-capped Chickadee.) 2.5 25. se. eee

$. ‘Eastern Wood) Pewee... ¢282 5402s. soe

Grr scaticet Vanaoer: i. 0c). s.cee 6 aes te oe 1

10; eastern Gardinale ce Sea ee ene
lie Vellowthraated Wireos: sos ose) edness
ioe eAcadian Plycatenets.. ecil we ke eee:
13. White-breasted Nuthatch...............

P5avwed-cyed) Lewhee: Go aos tebe Soe eek
iG; pCermlean: Wanbleti i itel. ivd die pda wrens
17. Northern Downy Woodpecker...........
18. Eastern Hairy Woodpecker..............
19. Northern Crested Flycatcher............
Die PECASCEEa OE RORDE 2)..¢ o) 2s eels se eee Aida ue ale ae

24. Northern Pileated Woodpecker... 5. .5::
PSE eNortheeneMickers is 265 ae oe tae teeth ck ne

27. Red-bellied Woodpeckers) oj o52 hai ce
28... Bastern Ruited Grouse i552) es ce eie ss ws

VOD OR BPR PRR BREN WWWO RADDA
DOr RFPORFR PRE NNWRPNFR HWW RP U&D~IN00
CRF OCC OFP FOF WN NUR ANIMONWD
SOFC OCORP RP REPRE NWNORFWHN WR ONIN ~I00

296 sBaskera Combate a3 6) 2.5 5) ss ye inte uke Binnee © present present present present
Porallpatcsy (eee ee dee 136 174 176 134
Total tmemicuals. oun ck ewe ce 272 348 Jaz, 268
Paics mer aerate | SEs Ln 220 2.6 pEr | 2.0
Paws perbectate: 6). 82 le 4.9 6.4 6.7 4.9
Averaze number ‘pairs per acre,:4 years 0.504)... 4. sae oe Se 2.28
Average number pairs per hectare, 4 years.............-..00-+05- Sat

July, 1936 A BEEcH-MapLe CLIMAx COMMUNITY 63

It will be noted that the summer of 1933 showed a slight increase in
numbers of nesting pairs, as contrasted with the great decrease in the mam-
mal population of this period. The birds were unaffected by the failure of
beech and sugar maple seeds, as these are not “basic” foods for them, as
they are in the case of most of the mammals. They were also not affected
by the dry weather of the summer so far as nesting activities were con-
cerned, as the drought was most severe during late June, July, and August,
when nesting activities were about over. If the bird population was af-
fected by reduced numbers of insects following the drought, or if reproduc-
tion was cut down during the breeding season one would expect it to be re-
flected in the numbers of breeding pairs in 1934.

Figure 15 shows the approximate locations of the nesting sites of the
176 pairs of birds listed in Table 17 as having been recorded in 1934. As
this figure is studied it should be kept in mind that we have here not only
a horizontal distribution of nesting sites, but a vertical one as well, ranging
from the tops of large trees, as in the case of the cerulean warbler, down
through the various levels of forest growth to the nesting site of the oven-
bird beneath the leaf-litter on the floor of the forest. Nesting territories
may be separated from each other by distance vertically as well as by dis-
tance horizontally. The writer recalls one nest of the red-eyed vireo ap-
proximately 70 feet (21.3 meters) up, in a large beech tree, and another
nest of the same species almost directly below it in a beech sapling about
6 feet (1.8 meters) from the ground. One vireo pair had a tree-top terri-
tory, the other almost a ground-level territory.

Using the breeding record as a basis for estimating the summer breeding
population of birds, and the weekly counts of numbers observed at all sea-
sons of the year, with due allowance for weather and other conditions af-
fecting the counts, Table 18 has been prepared as an attempt to estimate
the total bird population present at various times throughout the year. Only
the fairly well-known species are included in this list as such. Others are
totaled under appropriate headings. Young birds are not counted until they
become independent of parents. While the figures are an attempt to ap-
proximate the highest population numbers reached each month even this
figure is of course not constant during the month.

Foop CHAINS AND EcoLocicAL NICHES

While the numbers of nesting pairs of birds in the area may at first
glance seem to crowd the territory unduly, yet competition for food is
really limited by reason of the territorial relations of competing species or
individuals, and the particular ecological niches in the forest community oc-
cupied by others.

The barred owl, the ruffed grouse, and the robin probably do not com-

64 THE CLEVELAND MusEuM oF NATURAL HISTORY Se rte

g APPROXIMATE LOCATIONS OF
S NESTING SITES OF I76

f PAIRS OF BIRDS —

| SUMMER OF 1934

Fic. 15. Approximate locations of nesting sites of breeding birds in Table 17,
summer of 1934,

2—Barred owl 14— Robin 20—Redstart

4—Hairy woodpecker 15—Wood thrush 22—Scarlet tanager
5—Downy woodpecker 16—Red-eyed vireo 23—Cardinal

6—Crested flycatcher 17—Black-throated green 25—Towhee

8—Wood pewee warbler 26—Cerulean warbler
11—Chickadee 18—Oven-bird 27—Acadian flycatcher
12—Tufted titmouse 19—Hooded warbler 28—Yellow-throated vireo

13—White-breasted nuthatch 29—Red-bellied woodpecker

July, 1936 A BreecH-MapLeE CLimax COMMUNITY 65

TABLE 18. Estimated average bird population by months based on 1932, 1933, 1934, and
gures.

a] ile eee
Bas platy uo
Sle ie Gl é|a| 5
Slee a |S) a) eye ee tee
a hed ies len tees |e fice ZN Caceres
Permanent residents:
Mimtted Pitmouse............... Q2OR 200 TE a TA 1D 02). |) 22 ih ON 20.1 20) 26) Ze
Bees ardinal. . ck. eae LO) 10) } 20 10): 10} 10} 10.) 1001 10 1 AG TIO 18
White-breasted Nuthatch....... LE P1610 6 (6) 6) 12 Vig S626 fF 16 ie
Black-capped Chickadee......... 16; 16} 8; 8] 8] 8] 16} 16] 16 | 16 | 16 | 16
Northern Downy Woodpecker ...| 16 | 16} 8] 6] 6]|] 6{|10] 10] 16} 16 | 16 | 16
Eastern Hairy Woodpecker...... Sl ei abt A Se Ra SM a Wl WA al er pe od Ce (coe we
Red-eyed Towhee.............. 10; 10;10; 4); 4] 4] 4] 4]10] 10] 10 | 10
Northern Barred Owl........... 2 2 2 2 DU Wage? D Z 2 Z 2 2
Merencrn) biteated Woodpecker...) 2} 2} 2) °0| 0/-0] 21 2) 21 2] 2] 2
Red-bellied Woodpecker......... Pt OM Oat Onl Out bot 1 jn Bs oY
Eastern Ruffed Grouse.......... 1 1 1 OO Orr oO 1 1 1 1 1
ME Lk Ue 100 | 98 | 69 | 54 | 52 | 52 | 78 | 86 1116 {106 |102 {100
Summer residents:
(EE EOE re Ca SQ) G2 50) te BOW 20M ies aly erepal verse et eee
207) COONS iy A el eae (| S54 SO S220 TO) Diy a ey!
Peepeticaniimedstart. oi... c eee e fee cele cen 50 | 34 | 16 Bhd coral ee eles eee fetes ae
PIMMMCEN VARIED... 5. cece ec lewecls ees 28 | 28 | 20 | 14 | 10 alton cc oeee aimee
“LP SDLE Ec) 8 ao 40} 26|14/] 8] 6] 5
CEI es ie eislere [oie sede es » 1G) Ah G sle DD AW Se) ABA eee eae eae
astern Wood Pewee...........|....|...- TCC te Us ied We Sia 0 a | iy Dem ARN (ag ig
Wellow-throated Vireo.:.........|]:-..1..-. 10 8 6 2 a)
Pecamamibiveateher. 2)... 6. cs cla ece lees GG A ace ae eee age et
Black-throated Green Warbler...|.... LO 25 6 6 Jigs veo is hatne Aa (aa (ee egal (UO a ce
Master! Gow birds... ....2.625.. 6.6. ee Gna. Sieger. 2 Aa ai hala aa De a
Metmleam WV AERICE oes cc eclas ee lees PAOD D2 2 d) Dial
Northern Crested Flycatcher.....]....|.... ca Via 4 am Za eo Ra Wee ad a yh BO
Louisiana Water Thrush........|.... ALO Diy anil iene
RASteEMEPAOEDE. «ssc ce eclocecdeces ASN SDD Deciiks Aah Tey A ih i atten leet eae
PASCCHIMNROMING So) ae alee ee Guy Do Qe Or OOVSOOm ea ee ey eee
FITS) SO Rea Ieee 22 1365 |254 |184 |124 1195 |510 1250 | 2} 2] 2
Autumn and winter visitors,
transients and occasionals
Autumn and winter visitors...... ZO WSO LOM ais cine eine alee 25° 7S: | @SOF 30) | TOF ee
Red-breasted Nuthatch......... PLONE O78 lies ESN RMN VT aeh at 10) 1.60) 1:75 1, 50 f SOn 25
Bicte-colored Junco............. SO SON cae air lay be ereeeee eleven 50° 60) 25° ROVE es
Meransient Warblers. ...........|.06: LOM SOO Meee wis: PS NSO: SOM. Sil wcll. 2 lees
astern EHlermit Thrush.........].... SO its eee eo edie aa eeR IES ae SO) Tax coleluecee < eee ee
Miive-wacked UVhrush...,........|....|.0.. Toth Metenee (e Utne SOM. PSE ele wee. eee ee
Meciy-cheeked Vhrush. ..:./0)...05 fee eats eos sO Je aa es Ice Page LO) in atesicil esi WS catees bee aie ene
BemsonisMRtUSA. oe). e ee ec leew ede see PRR A 2 a TOOT Ss Pes ee ies ee
White-throated and Fox Sparrows]....| 20 | 50 |....|....].... LO TS flO: eae eae
Mecasional’visitors..... 4/2)... ss. 151) 2001.20 5 S20 SOL hs take ote Gree) bale
TEATS AS A a 105 |200 |505 5 5 | 35 1295 |465 196 110 | 50 | 55
SE LOTT a a 205 |320 |939 |313 |241 |211 {568 1061 562 |218 pa 157

pete with any other species for food. The woodpeckers, while all seeking
their food in the same way, probably overlap very little, as the different
species work upon different parts of the larger trees, and the downy pays a

66 THE CLEVELAND Museum oF Natura History Se ee

good deal of attention to lesser growth, not worked by the other larger birds.
While the 3 pairs of white-breasted nuthatches may sometimes come into
competition with the downy woodpeckers, their nesting sites are widely
separated so that competition is reduced to a minimum. The nuthatches
may come into real competition with the chickadees and titmice, but this
combination represents but 18 pairs of birds at its recorded maximum dur-
ing the nesting season, which allows 3.6 acres (1.45 hectares) to the pair
if the territory were evenly divided between them. As a matter of fact the
chickadee and titmouse nesting territories seem to be complementary to
each other, while the nuthatches cover a much wider range than either of
the others.

So far as food habits are concerned the flycatchers form a group by
themselves, each species having its own special hunting ground. The crested
flycatcher pairs keep strictly to its part of the woods. The Acadians each
have their own little glen, with a stream running through it, and no other
flycatchers in the vicinity. The wood pewees have widely separated terri-
tories of their own in the higher levels of the forest. The hooded warblers
and the redstarts may compete at times with each other, yet in a general way
they are somewhat complementary as the redstart usually hunts in higher
territory than does the hooded warbler.

The birds whose food habits call them frequently or almost entirely to
the ground in summer—the Louisiana water thrush, oven-bird, wood thrush,
cardinal, towhee—have about 2 acres (0.8 hectares) per pair on the average,
which would furnish them with plenty of food supplies not drawn upon to
any extent by other species.

This reserves the leafy foliage of the forest trees to the tanagers, vireos,
and cerulean warblers—not entirely, of course, but this is their particular
niche. The black-throated green warblers seem to keep pretty closely to the
upper parts of the large hemlock trees during the nesting season, and their
nesting sites are widely separated.

So far as factors within the environment are concerned this summer
population of breeding birds seems to be regulated largely in its distribution
and density within the area by the available food supplies, and the number
and fitness of nesting sites and ecological niches offered by the forest environ-
ment.

It is difficult, if not impossible, to assign places of relative influence to
particular species of birds inhabiting the community. In the aggregate the
birds consume an immense amount of insect food as well as considerable
vegetable matter. Certain groups, however, may be singled out as of out-
standing importance because of numbers, or because of their constant ac-
tivity throughout the year.

Probably the most influential of these groups is that composed of the

July, 1936 A BrEecH-MAPLE CLIMAX COMMUNITY 67

hairy and downy woodpeckers, chickadee, tufted titmouse, and white-breasted
nuthatch. These are all permanent resident species, and their numbers are
considerably increased at certain times of the year. They constitute a com-
pany of very diligent searchers after insects on and under the bark of trees,
and in dead wood, dividing between them the territory to be covered, so
that very little tree surface escapes their attention. Larvae of beetles and
other insects, eggs, pupating insects, hibernating insects, spiders, myriapods,
and others form the bulk of their diet. Beech nuts are eaten by all of these
species as well as many wild fruits. Their limited range keeps them within
the area, and thus entirely dependent upon it for their food supplies.

There is no doubt but that the heaviest summer influence is exercised
by the group composed of wood thrush, oven-bird, hooded warbler, red-
eyed vireo, redstart, and scarlet tanager. All these are highly insectivorous.
They cover all levels from ground to tree-tops, and so serve as an efficient
check to the summer insect population. Yet their stay in the area is limited,
and their activities are spread over too short a space of time to give them
first rank in influence. They supplement the activities of the first group
when the insect tide is rising to its greatest proportions, and it may be ques-
tioned whether, in the absence of either group the forest could long con-
tinue to maintain itself. It is of interest to note how, in August, the chimney
swifts and purple martins, hunting immediately above the forest roof, com-
plete the occupation of all levels in the community of forest animals.

Another great bird group is that composed of robins, hermit thrushes,
and olive-backed thrushes in autumn. Although these birds come mainly
for forest fruits, among which the wild grape ranks high, they also spend
much time raking over the dead leaves of the forest floor for insect food.
Of great importance also is the frequently large group of migrating war-
blers in spring. Though their stay in the area is brief, they rid the develop-
ing foliage and bark surfaces of the trees of many newly hatched insects
before the minute larvae have developed into larger consumers of foliage.

The most important non-breeding bird in the area is the red-breasted
nuthatch. Though present only in alternate winters during the period of
this study, and though their numbers are marked by considerable fluctua-
tion, they often surpass in numbers all other species put together. Their
length of stay covers a period of over seven months, and while present they
are apparently strictly resident. They are very diligent in their pursuit of
food, spending much time searching the bark, limbs, twigs, and decayed
places of the forest trees. Beech nuts are taken with evident relish. The
red-breasts work all the way from the ground to the tops of the highest
trees, and do not hesitate to enter the cavities of decaying logs.

The barred owl and the pileated woodpecker stand out because of their
size and year-round activity. The woodpecker’s range is much larger

68 THE CLEVELAND MuseuM OF NATURAL HIsToRY sie

than the area under study, and though a single pair, sometimes augmented
by young in summer, or another presumably immature bird in winter,
spend much time in the area, they are not dependent upon it for their liv-
ing. Their work on hemlock trees infested by the bark-boring beetle is
very evident. They also do much work in digging for grubs and ants in
trees like the white ash, in which the heart-wood is decayed, but the sap-
wood is still sound. The pileated woodpecker is an influential bird in the
area, but important in a supplementary way rather than primarily. On the
other hand, the barred owl is more nearly resident, probably not going far
beyond the limits of the area on his hunting trips. In summer the single
pair of owls breeding in the beech-maple association seem to hold them-
selves and their young quite closely to the interior forest, appearing to be
entirely dependent upon it for food supplies.

That short-tailed shrews form the bulk of the owl’s diet is very appar-
ent. The barred owl has frequently been observed in the act of catching
these little animals, and no cast pellet so far examined has failed to include
jaws or skulls of from 1 to 4 shrews (Blarina brevicauda). Remains of the
white-footed mouse are also frequently found, but not always, as is the case
with the shrew. Though these two animals probably make up most of the
barred owl’s diet, the writer is inclined to the opinion that a considerable
number of the smaller insectivorous birds are also consumed, especially in
early spring when the summer resident bird population is concentrating its
activities upon the incubation of eggs and rearing of young. The frequently
deserted and destroyed nests found at this season strongly suggest that the
incubating or brooding bird has come within range of the owl’s telescopic
vision, and has been picked off—sometimes nest and all. When the owl’s
nesting site was examined in April 1932, after the young had come off,
feathers of hairy woodpecker, red-bellied woodpecker, blue jay, cedar wax-
wing (Bombycilla cedrorum Vieillot), bob-white, and horned lark (Otocoris
alpestris Linn.) were recovered from the débris at the bottom of the nesting
cavity. The presence of horned lark feathers certainly indicates an ex-
cursion into the open fields outside the woods, and the bob-white and cedar
waxwing remains are corroborative evidence of the same thing. The barred
owl therefore is of large importance in the community as a check upon the
numbers of shrews and mice, and to a much less extent as a limiting in-
fluence on the reproduction of smaller birds within the area.

It is more difficult to classify the birds of the area on the basis of food
habits than it is the mammals. The barred owl is the only one among the
permanent residents to be classed as a carnivore. Yet he is also an eater
of insects (Fisher 1880). The other permanent residents, while all con-
suming considerable vegetable matter, particularly beech nuts, could prob-
ably, with the possible exception of the ruffed grouse, get along quite well in

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 69

the absence of vegetable provender. The summer residents are predom-
inantly insectivorous—the flycatchers, warblers, vireos, and tanager com-
pletely so (Forbush 1927, 1929). Thus it appears that the bird population
of the area, with the exception of the barred owl, is supported mainly by the
insect food supplies of the forest, and only secondarily, and to a much less
extent, by plant products.

SEASONAL CHANGES IN THE BirD POPULATION OF THE AREA

One of the main characteristics of the bird population of the area under
study is its instability. Fluctuations in numbers are at times extreme, and
even in winter numbers are far from constant. While the total of species
listed is 83 (Table 16), only 11 of these are classed as permanent residents.
Even the summer nesting species constitute a rapidly shifting element in
the total bird population. What the increase in numbers may be when
young birds are launched upon independent careers is largely a matter of
conjecture, for it is certain that most of the summer resident species leave
the area with their young as soon as the latter are capable of sustained
flight. One must also allow for a large mortality among both young and
old, and must count upon a large percentage of failures of nesting pairs to
bring any young birds off the nest. Butts (1930), working with banded
white-breasted nuthatches, noted the frequent disappearance of apparently
permanent resident birds. Out of 21 individuals, 10 disappeared in two
years, and only one, banded at the beginning of his study, lasted throughout
the three years of its duration. Probably the length of life of most small
birds is not more than two years on the average. The probability is that
when the summer is over, the net increase in the bird population is not large.
Depletions from the ranks of the older birds are made good by the entrance
of younger birds into the community, perhaps in numbers just large enough
to absorb the losses that are due to come as a result of autumn and winter
casualties, and so maintain the species at about its normal numbers.

Reference to Table 18 will give an idea of constantly changing numbers,
but when this is reduced to diagrammatic form (Fig. 16) the often ex-
treme and abrupt fluctuations as well as the more gradual changes in the
bird population of the area are clearly apparent. As the red-breasted
nuthatch has been present only on alternate years, this species is set off
from the other winter visitors.

It is in the spring and autumn that the fluctuations in number of birds
in the area are relatively enormous. During the first half of the month of
May the woods are flooded with migrant species on their way to more
northerly breeding grounds. At the same time the greater number of the
summer resident species are arriving. In October and November the woods
are again filled with large numbers of robins and flocks of migrating thrushes

70 THE CLEVELAND Museum oF NATURAL HIsToRY oS

SENS

I
NK

=== PERMANENT RESIDENTS ZZ TRANSIENTS
(TMM WINTER VISITORS Beet} ROBINS

IS8G9 SUMMER RESIDENTS L-_JOCCASIONAL VISITORS
E===)RED-BREASTED NUTHATCH:PRESENT ALTERNATE YEARS

Fic. 16. Seasonal fluctuations in the bird population of the area under study on
the basis of estimates and averages of weekly counts for 1932, 1933, and 1934.

and sparrows. The winter visitors are already well massed in October
and reach a peak of numbers in November. These two months witness the
largest assemblage of birds in the area during the year. The two periods
of least numbers are the second week in August, when the summer popula-
tion is depleted, and the last week in January, when many of the winter
visitors have left the area and the influence of the northward movement is
so soon to come is not yet evident.

Tue REPTILES OF THE AREA

During the first two and a half years of this study the only reptiles ob-
served in the area were snakes. In the spring of 1934 Mr. M. B. Walters”

July, 1936 A BEecH-MAPLE CLIMAX COMMUNITY 71

and the writer together were fortunate enough to get very good sight rec-
ords of several five-lined skinks, thus adding a lizard to the list. The reptiles
thus far observed, specimens of all of which except the skink have been
collected, are shown in Table 19. Scientific names are as used by Ditmars

(1920).
TABLE 19, Reptiles of the area.

Five-lined Skink Eumeces quinquelineatus (Linn.).
Ribbon Snake Eutaenia saurita (Linn.).

Common Garter Snake Eutaenia sivtalis (Linn.).

Common Water Snake Tropidonotus fasciatus sipedon (Linn.).
De Kay’s Snake Storerta dekayt (Holbrook).

Red-bellied Snake Storeria occipitomaculata (Storer).

Pilot Blacksnake Coluber obsoletus (Say).

Milk Snake Ophibolus doliatus triangulus (Daudin).

The skinks were observed on May 7, 1934, running in and out from
under the loose bark on a large fallen beech log, evidently enjoying the bril-
liant spring sunshine which was a feature of that day. Three were seen at
one time and two at another, but the total number may not have been more
than three. One of these was in the “blue-tailed” stage, the others brown,
with characteristic red heads. As this is the only recorded occurrence of
these animals in the area their numbers must be few.

The common garter snake and the ribbon snake, while regularly found,
are not abundant. Five small immature common water snakes have been
taken in or near the course of the main stream bed in the area. This spe-
cies is common in a pond about a half mile west of the area, and these
young snakes may possibly have come into the woods from that direction.
Three specimens only of the milk snake have been taken. Five fine exam-
ples of the red-bellied snake have been found, one of which, while in tem-
porary captivity, gave birth to 21 living young. The period of activity of
these snakes is from about May 1 to the latter part of October.

The only reptile inhabiting the area that can be said to be present in num-
bers is the pilot blacksnake. During the summer of 1931 12 or 13 of these
beautiful serpents were taken in the area. Most of these were over 4 feet
(121.9 cm.) in length; several were over 5 feet (152.4 cm.); and the cast
“skin” of one has been found measuring 6 feet 1 inch (185.3 cm).

After several days in captivity the pilot blacksnake can be handled easily.
Captive specimens have proved to be remarkably expert in climbing, and
exceedingly muscular in action. According to Ditmars (1920), the snakes
of the genus Coluber, to which the pilot blacksnake belongs, feed upon
warm-blooded prey exclusively—especially the smaller rodents—and also
upon birds and their eggs. One is mentioned as having disgorged a well-
grown cottontail rabbit upon being captured. Captive snakes of this species,
observed by the writer, took three young scarlet tanagers which were found
dead, their nest having been blown down in a storm. One was reported as

72 THE CLEVELAND Museum oF NaturRAL History so fn

having been seen coiled about a wood thrush’s nest some 20 feet (6 meters)
above the ground in a young sugar maple sapling, having apparently made
a meal of the young birds.

When released, these snakes quickly disappear beneath the leaf litter,
or into any near-by cavity under a log or stump. One can easily see what
an efficient hunter of chipmunks, mice, shrews, and young birds an animal
of this sort might be.

The earliest record of the appearance of the pilot blacksnake in spring
in the area is May 2. On this date the writer saw a fine specimen which
when measured later proved to be 4.5 feet (137.1 cm.) in length. There
was considerable soil adhering to the reptile’s back, as though he might
have just emerged from an underground retreat. He was lethargic, allow-
ing the camera tripod to be set up within a few inches of his head, and when
picked up showed no signs of fight, which is unusual in this species. The
inference was that he had just emerged from hibernation. As these snakes
disappear in October, this allows for a full six months period of activity.

As to the rate of reproduction of the pilot blacksnake, one captive speci-
men, 5 feet 4 inches (162.5 cm.) long deposited 22 eggs on July 18. Several
days later, another of lesser length laid 13 eggs.

The pilot blacksnake is well distributed throughout the area, having
been observed in all parts of it, including beech-hemlock environment. Dur-
ing the past three years 10 of these snakes have been marked by making a
deep V-shaped nick in the outer edge of one of the ventral plates, and then
have been set at liberty. The number of the marked plate, counting from
the anus has been recorded in each case, being a different number for each
snake. One of these, marked in the summer of 1932, was recovered near
the point of original capture and set at liberty again May 6, 1934. This
would seem to indicate a rather closely resident character for these serpents.
The numbers of pilot blacksnakes, judging from captures made, seemed
to be fairly constant in 1932 and 1933, but were distinctly less in 1934 and
1935. This is apparently correlated with the falling off in numbers of
small mammals in 1933 and 1934.

The importance of the garter snake, ribbon snake, and water snake in
the area seems relatively very small because of their insignificant numbers,
small size, and food habits which restrict them to insects, worms, frogs,
and toads. If the milk snake should be found here in numbers, it would
need to be classed as an important member of the community, but at pres-
ent there is no evidence that this is the case. The red-bellied and De Kay’s
snakes may be present in greater numbers than the few records indicate.
They are secretive in habits, and normally not often seen. Ditmars (1920)
says that the food of these snakes consists of earthworms, slugs, and the
soft-bodied grubs of beetles. Their burrowing habits might make them

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 73

important insect hunters in decaying stubs and logs. If present in num-
bers they would therefore be important members of the forest community.

The pilot blacksnake must be classed as among the really important mem-
bers of the community. In size, in numbers, in food habits, in rate of re-
production, and in activity it ranks well up among the more important ani-
mals of the area.

Tue AMPHIBIA OF THE AREA

The list of amphibians thus far discovered in the area is shown in

Table 20.
TABLE 20. Amphibia of the area.
Toads and frogs

American Toad Bufo americanus Le Conte.

Fowler’s Toad Bufo fowleri Putnam.

Pickering’s Hyla Hyla crucifer Wied.

Green Frog Rana clamitans Latreille.

Eastern Wood Frog Rana sylvatica Le Conte.
Salamanders

Brown Salamander Desmognathus ochrophaea Cope.

Dusky Salamander Desmognathus fusca (Rafinesque).

Spotted Salamander Ambystoma punctatum (Linn.).

Mole Salamander Ambystoma talpotideum (Holbrook).

Red-backed Salamander Plethodon cinereus (Green).

Slimy Salamander Plethodon glutinosus (Green).

Red Eft Triturus viridescens Rafinesque.

Toads and frogs are not abundant in this forest community. But 3
records of the American toad, and 5 of Fowler’s toad have been made. The
wood frog and Pickering’s hyla occur more frequently but have never been
observed in numbers. Each is generally distributed throughout the area,
but more often encountered on the lower levels than on the higher land.
During the summers of 1931 and 1932 the green frog was the common frog
of the area. Nearly every pool of standing water had its one or more
small half-grown frog of this species. During dry weather they would
disappear, but after a rain would appear again. In 1933 green frogs were
scarce in the area, and in 1934 and 1935 they were completely absent. After
the dry summer of 1933 all frogs became exceedingly scarce in the area.

Nor are salamanders abundant. The commonest species is Triturus
viridescens in the second larval form commonly known as the “red eft.’ The
adult form is very common in a pond to the west of the area. After a rain
in summer these brilliant red salamanders may be seen walking abroad
quite fearlessly. The writer has seen both the raccoon and the crow
refuse to eat the red eft, though they would take salamanders of other spe-
cies. Perhaps this matter of being unpalatable may account for the some-
what greater abundance and lack of fear of this species. The dusky sal-
amander is quite abundant in certain wet places under stones in stream beds.
The red-backed and brown salamanders are both found sparingly under
logs and bark or in moist dead wood. The slimy salamander seems to be

74 THE CLEVELAND Museum oF NaAturRAL History Sa Pe

rather generally distributed through both associations, but quite sparingly,
while the spotted salamander and the mole salamander are rare. After the
very dry summer of 1933 all salamanders became quite rare in the area, the
red eft being the only species that seems to have escaped a drastic reduction
in numbers.

Not much can be said at this time as to the relative importance of am-
phibia in the area. That frogs are an item in the fare of the raccoon may
be infered from the abundance of the raccoon tracks about the places where
frogs are to be found. Doubtless most of the other amphibians, when en-
countered, would be added to the raccoon’s diet. The same would hold true
for the skunk and the opossum, and doubtless for other mammals and some
birds. The ribbon snake, the garter snake, and the water snake are known
to be addicted to amphibian fare (Ditmars 1920).

On the other hand the toads, frogs, and salamanders fill a definite niche
in the economy of the forest as large consumers of insects, slugs, and larvae.
Yet because of their small numbers in the area under study they do not
seem to be of great importance to the community as a whole.

INVERTEBRATES OF THE AREA

The molluscs listed in Table 21 have all been collected as live animals
within the area and the dead shells of many of them are quite common on
chipmunk feeding tables and in shrew runways.

TABLE 21. Molluscs of the area.

Polygyra stenotrema (Ferussac). Polygyra fraterna (Say).
Polygyra tridentata (Say). Omphalina inornata (Say).
Polygyra fraudulenta (Pilsb.). Omphalina fuliginosa (Griffith)
Polygyra albolabris (Say). Anguispira alternata (Say).
Polygyra albolabris dentata Tyron. Succinea retusa Lea.

Polygyra thyroides (Say). Succinea ovalis Say.

Polygyra clausa (Say). Circinaria concava (Say).
Polygyra zaleta (Binney). Vitrea hammonis (Str6m.)
Polygyra palliata (Say). Zonitoides minuscula (Binney).
Polygyra hirsuta (Say). Limax maximus Linnaeus.

Cahn and Kemp (1929) mention finding the shells of Anguispira alternata
and Polygyra stenotrema in nests of the white-footed mouse. Shull (1907)
found that in winter, snails of the genus Polygyra (albolabris, multilineata,
profunda, thyroides, fraterna) formed much of the food supply of the short-
tailed shrew. That land snails are preyed upon by certain beetles and their
larvae is also established (Lengerken 1934, Boettger 1934). Boycott (1934)
says that competition between land snails is an almost negligible factor, and
that there is no specific relation between Mollusca and trees.

The crayfish Cambarus bartoni robustus Girard is common in the main
stream bed of the area. Crayfish are said to be fed upon by raccoons, sal-
amanders, frogs, birds, snakes, turtles, and fishes (Turner 1926). The same

July, 1936 A BeecH-MapLe CLIMAX COMMUNITY 75

author says that crayfish are generally omnivorous, eating almost anything
of an organic nature that comes to hand, whether of animal or vegetable

material.
The temporary pools in the beech-maple association were studied in the

spring of 1933 by Dr. Norma C. Furtos. During this study the temperature
of the water varied from 40° C. (39.2° F.) on April 8 to 15° C. (59.° F.)
on April 28. Organisms found are listed in Table 22.

TABLE 22, Organisms in temporary pools.

Arcella sp. Candona decora Furtos.

Trachelomonas sp. Candona brevis Muller.

Eucypris sp.

Eucypris fuscata (Jurine) var.
gigantea Furtos.

Alona guttata. Eucypris sp.

Chydorus sphaericus (O. P. Miller). Cypricercus tincta Furtos.

Planaria velata Stringer. (common)

Cyclops viridis Jurine.
Cyclops crassicaudis Sars,
Cyclops serrulatus Fischer.
Cyclops bicuspidatus Claus.

Cryptocandona sp.

Gammarus sp.
Eucrangonyx Sp.

Canthocamptus staphylinoides (Jurine). Macrobiotus sp.

In addition to the species listed (Table 22) aquatic earthworms were
commonly found, a small crayfish was taken, and larvae of caddis fly, may-
fly, Diptera and Coleoptera, were found to be common. Mosquito larvae were
very abundant. Red water mites were common.

Obviously no complete understanding of the dynamics of the forest can
be secured without a thorough study of its insect life. This should be done
quantitatively as well as qualitatively. On all sides the evidences of the
activities of wood-boring and bark-boring insects are apparent. There are
_ bees and flies and wasps and butterflies and small midges and mosquitoes in
the air. Moths large and small are common. The big syrphid fly Muilesia
virgimiensis Dru. is common, as are the scavenger beetles Necrophorus mar-
gimatus Fab. Camel crickets are abundant in the humus in certain places.
Ground beetles are abundant everywhere. The yellow-jacket Vespa com-
munis De S. and the white-faced hornet Vespula maculata (Linn.) are very
common. The writer counted 9 large nests of the latter species in the win-
ter of 1934-35 in the area. The work of the flat-headed hemlock borer
Melanophila fulvogutiata Harr. is very noticeable in the beech-hemlock
areas. The fungi of the area support a numerous insect population. In
September the white woolly aphid Schizoneura imbricator Fitch. is often
noted on the branches of the beech. Various kinds of caterpillers are noted
on the foliage of the trees, and vireos and warblers seem to find much to
glean from foliage beyond the range of one’s vision. In August and Sep-
tember the hum of insects is a definite feature of the forest.

By reason of their numbers, their destructive activities from the stand-
point of plant life, their rdle as reducing agents in dead and decaying tim-

76 THE CLEVELAND MUSEUM OF NATURAL HIstTory Se hao

ber, their interrelations within their own group, their relations to other
animals as parasites, and their great importance as a source of food supply,
insects occupy a place of great significance in the biotic community. While
their importance is recognized, it is impossible here to do more than call at-
tention to it.

ECOLOGICAL CLASSIFICATION OF ANIMALS

The study of animal ecology has not as yet developed a commonly ac-
cepted terminology. As that suggested by Smith (1928) does not seem to
the writer to be entirely adequate to some of the situations arising in this
study, the following special terms are herein employed:

1. Predominants are those animals which are most abundant in num-
bers and of greatest influence in the community.

2. Members are those animals that are present in smaller numbers than
predominants, and therefore of lesser influence. The term may be applied
to a single individual.

Both predominants and members may be further subdivided by employing
the following adjectives.

1. Permanent. Used to indicate constant presence and activity through-
out the year.

2. Fluctuating. Used to indicate marked lack of constancy in numbers
and activity at different seasons, although present throughout the year.

3. Seasonal. Used to indicate presence or activity at one or more
seasons of the year and entire absence or inactivity at others.

4. Incidental. Used to indicate irregular and inconsequential occur-
rence in the community.

TABLE 23. Ecological classification of vertebrates in the beech-maple association.

Predominants Members
Permanent predominants Permanent members

Mammals Mammals
Short-tailed Shrew Eastern Red Fox
Northern White-footed Mouse New York Weasel

Southern Red Squirrel

Small Eastern Flying Squirrel
Domestic Dog

Domestie Cat

Birds
Eastern Hairy Woodpecker
Northern Downy Woodpecker
Black-capped Chickadee
Tufted Titmouse
White-breasted Nuthatch

Fluctuating predominants
Mammals
Northern Gray Squirrel
Eastern Chipmunk
Pine Mouse
Birds
Eastern Robin

Birds

Eastern Ruffed Grouse
Northern Barred Owl
Northern Pileated Woodpecker
Red-bellied Woodpecker
Eastern Cardinal

Fluctuating members
Mammals

Cottontail Rabbit
Smoky Shrew

Birds

none

July, 1936

Seasonal predominants
Mammals
none

Birds
(nesting species
Red-eyed Vireo
Wood Thrush
Hooded Warbler
American Redstart
Oven-bird
Eastern Wood Pewee
Scarlet Tanager

(transient species)
Eastern Hermit Thrush
Olive-backed Thrush

(winter resident species)

Red-breasted Nuthatch
Reptiles

Pilot Blacksnak

Amphibians
Green Frog
Wood Frog
Pickering’s Hyla

Red Eft
Red-backed Salamander

Fox Squirrel
Meadow Mouse
Star-nosed Mole

A BreecH-MAPLE CLIMAX COMMUNITY

Seasonal members
Mammals
Virginia Opossum
Eastern Raccoon
Eastern Skunk
Southern Woodchuck
Big Brown Bat

Birds
(nesting species)
Crested Flycaster
Acadian Flycaster
Eastern Phoebe
Yellow-throated Vireo
Cerulean Warbler
Louisiana Water Thrush
Rose-breasted Grosbeak
Red-eyed Towhee

(transient series)
American Woodcock
Yellow-bellied Flycatcher
Winter Wren
Gray-cheeked Thrush
Wilson’s Thrush

Eastern Golden-crowned Kinglet
Eastern Ruby-crowned Kinglet

Blue-headed Vireo

Black and White Warbler

Blue-winged Warbler
Nashville Warbler
Magnolia Warbler

Black-throated Blue Warbler

Blackburnian Warbler

Chestnut-sided Warbler

Blackpoll Warbler

Connecticut Warbler

Canada Warbler

Purple Finch

White-throated Sparrow

Fox Sparrow

Yellow-bellied Sapsucker

(winter resident species)

Eastern Goldfinch
Reptiles

Five-lined Skink

Ribbon Snake

Garter Snake

Red-bellied Snake

De Kay’s Snake

Milk Snake
Amphibians

American Toad

Fowler’s Toad

Dusky Salamander
Brown Salamander
Slimy Salamander

Incidental Members

Mammals
Hairy-tailed Mole
Red Bat
Stilver-haired Bat

78 THE CLEVELAND Museum oF NATURAL HISTORY Sci. Pub.

Vol. VI
Birds
Turkey Vulture Chimney Swift Eastern Blue Grosbeak
Sharp-shinned Hawk Ruby-throated Hummingbird Indigo Bunting
Cooper’s Hawk Northern Flicker Common Redpoll
Eastern Red-tailed Hawk Northern Blue Jay Red Crossbill
Broad-winged Hawk Purple Martin Slate-colored Junco
Eastern Bob-white Eastern Crow Eastern Whip-poor-will
Eastern Mourning Dove Starling Reptiles
Yellow-billed Cuckoo Brown Creeper Common Water Snake
Great Horned Owl Carolina Wren Amphibians
Eastern House Wren Bronzed Grackle Spotted Salamander
Eastern Nighthawk Eastern Cowbird Mole Salamander
ASPECTION

Aspection, or phenology, has to do with the visible evidence of the re-
sponses which plants and animals make to the changing of the seasons.
It is usual to divide the year on the basis of plant activity into six main
periods, or aspects; the prevernal, vernal, aestival, serotinal, autumnal, and
hibernal (McDougall 1927, Weaver and Clements 1929). While this has
been adopted also for animals as a convenient way of designating seasonal
changes, it is difficult to assign time limits to any of these divisions since
one merges insensibly into another. In discussing fluctuations in abundance
of mammals, birds, and other animals in the community under study, ref-
erence has been made to certain seasonal changes in numbers. ‘These also
constitute parts of seasonal aspects.

The main changes to be noted in the aspect of the forest composing the
beech-maple association at North Chagrin are somewhat as follows:

1. Prevernal aspect. Although February is usually the coldest month of
the year (Fig. 3) and most of its aspects are hibernal, yet in this month
mosses and lichens definitely take on new color, and during the latter part
of the month, crows and hawks appear. Tufted titmice and cardinals begin
to whistle occasional spring-like notes, and the pileated woodpecker becomes
noisy. The woods are very wet from melting snow or rains, and standing
water in pools is a feature of the aspect.

By the first week in March some of the plants that have carried green
leaves over winter, like spring cress and wild blue phlox, or some of the
violets, show definite responses in the erection of their stems and leaves,
while the green leaves of wintergreen, partridgeberry and trailing arbutus
take on new freshness. Although there is much alternation of freezing and
thawing during the month the development of herbaceous vegetation is only
temporarily checked by low temperatures, and responds rapidly to increas-
ing warmth. Beech nuts and sugar maple seeds sprout in March even though
they are bound to be covered with snow or encased in ice before the month
is out.

By the latter part of March hepaticas and spring beauties may be found

July, 1936 A BrEEcH-MApPLE CLIMAX COMMUNITY 79

in bloom—the hepaticas on certain south-facing slopes, and the spring beau-
ties on the less wet places of the higher portions of the area. Certain spe-
cies of mosses and lichens will be developing their fruiting bodies. Proto-
coccus on beech trunks, and the green alga of the temporary pools start new
growth. Throughout the month the barred owl has been sitting on her eggs,
and both skunk and woodchuck have come out of hibernation. The tracks
of raccoons have become common, chipmunks appear in numbers, bird music
increases, and woodpeckers indulge in much drumming.

Unless delayed by snow or unduly low temperatures a great change takes
place in the aspect of the forest during the latter part of March and the first
of April. The higher land begins to green with the developing leaves of
yellow adder’s tongue, cut-leaved dentaria, and spring cress. Many plants
of spring beauty come into bloom but they do not add appreciably to the
green of the forest floor as the color of their leaves is more red than green.
Many other plants are now recognizable. The spikes of both red and white
trillium are emerging, rue anemone is in the “grape” stage, sweet cicely,
Canada violet, blue cohosh, early meadow rue, golden seal, wild leek, wild
blue phlox, swamp buttercup, and dutchman’s breeches may all be recog-
nized by the practiced eye. The heart-shaped cotyledons of seedling jewel-
weed are thickly scattered in certain locations. Many clumps of hepatica
in bloom may be seen in favorable situations. The flower buds of elms
and red maples are large and swollen, and gray squirrels begin to cut them
down for food. The voice of Hyla crucifer is added to the early spring
bird music. On the lower levels near the ground are many insects, partic-
ularly mosquitoes, small flies, small bees, and larger honey bees. Mourning
cloak, question mark, and red admiral butterflies may be seen. The winter
bird companies begin to break up.

By the second week in April the greening of the forest floor has pro-
gressed considerably. The foliage of spring beauty, spring cress, cut-leaved
dentaria, dutchman’s breeches, hepatica, and other plants has now definitely
occupied the ground. This is the beginning of the “wildflower” display.
From April 10 to 15 hepaticas will be at the height of their blooming season,
and so quickly does the peak of their blossoming time pass, that one of
these days will stand out above others for the abundant display that it of-
fers. Spring beauties will begin to occupy the ground with their pink and
white blossoms a few days later. Both these plants close their flower-heads
on overcast, rainy, or cloudy days, so that their color pattern on the forest
floor may be withdrawn at times. If snow comes, their flowers or leaves
will often be seen protruding from the surface of the white blanket. The
woods are still wet at this time of year, and standing water continues in the
surface pools.

The buds of the forest trees are swelling now and so adding a new note

80 THE CLEVELAND MuseuUM OF NATURAL History og

of color to the upper stories of the woods. Red-berried elder is sprouting
vigorously. Fly honeysuckle comes into bloom. The leaves of wild black
cherry break from the buds. The round-leaved violet comes into bloom,
the flowers appearing before the leaves.

Titmice are constantly calling and woodpeckers drumming. The first
of the summer resident birds—the phoebe—may be found about the wet
places where insects are on the wing. The temporary pools swarm with
minute forms of plant and animal life. As increasingly more sunlight
reaches the forest floor through the leafless branches of the trees, differences
in humidity as between day and night often become extreme. By the latter
part of April yellow adder’s tongue reaches a climax of bloom so that cer-
tain places are suffused with its yellow color. Red trilliums are now at
their best, and some white trilliums are blossoming. Leaves of May apple
begin to be noticeable. The breaking of the leaf buds on the trees gives the
branches a filmy appearance and the sky begins to be shut out a bit.

The first week in May marks the high tide of the wild-flower display in
the beech-maple association. The great white trillium now occupies the
center of the stage and many of the less numerous species are in bloom.
Spring beauty spreads itself like a pink carpet on the higher lands. The
forest floor seems to be fully occupied with herbaceous growth, and sprout-
ing seedlings of beech and sugar maple are recognized by their cotyledons.
The buds on the forest trees now begin to break, and on a certain day the
air will be filled with the falling bud-scales of beech. When viewed from
a distance these opening buds give characteristic color to the forest trees.
Brown indicates beech; green, sugar maple; and red, red maple. Both the
beech and the sugar maple now come into bloom—the blossoms of the sugar
maple imparting to the trees a brilliant yellow-green color in sunlight. Gray
squirrels will be noted in the tree tops feeding upon beech blossoms.

This is the time when the summer resident birds appear, and when the
woods may be flooded with warblers and other transient species. On the
newly developing foliage tiny caterpillars appear, and in the air there is a
surge of newly awakened insect life. Permanent resident birds are already
nesting.

In the beech-hemlock association the Canada mayflower is the only herba-
ceous plant that forms a ground cover. Spikes of this plant appear in late
April and the flowers begin to open about May 15.

2. Vernal aspect. The aspect of the forest is now rapidly changing, due
to the unfurling of the leaves on the trees. Those on the lower levels are
the first to expand, making a story of green below the tree tops. About the
10th or 11th of May occurs a day when the trees are hazy with the yellow-
greens of newly unfolding leaves. During the time of leaf development on
the trees the great white trilliums begin to turn pink and then to fade. As

July, 1936 A BEECH-MAPLE CLIMAX COMMUNITY $1

they pass, the floor of the woods again takes on a yellow hue as three species
of yellow violets come into their full flowering season. After them comes
the time of flowering of wild blue phlox and wild geranium, but these plants
are not in sufficient numbers to add much color to the picture. Seedlings of
sugar maple and beech now contribute a good deal of green to the floor of
the forest as the earlier herbaceous plants disappear. The green of new
leaves of hepatica and May apple also add to the green mantle. From now
on the flowers of the herbaceous vegetation are of the more inconspicuous
types. The elms and the red maples have already shed their seeds.

As the leaves on the larger trees of the forest develop, less and less blue
sky can be seen, until there arrives a time in the latter part of May when the
fully expanded leaves shut out the sunlight altogether. The woods are now
dark, even at mid-day. This is the time when the spring chorus of the chip-
munk reaches its crescendo. These animals are very much in evidence as the
dense curtain of foliage shuts the arboreal squirrels from view. The poikilo-
therms—pilot blacksnake, frogs, toads, salamanders, and snails—are now
noticeable. The month of May also witnesses the great northward flight of
the transient bird group. Warblers will be noted in the woods, and sparrows
under the grape tangles and other débris. It is during the first two weeks of
May that the summer resident birds are occupying their breeding territories.
The woods are vocal now with bird songs. Insects become abundant. The
Acadian flycatcher and the wood pewee complete the list of the summer resi-
dents. Now comes the great period of nest building and incubation of eggs.
The barred owl, nesting earliest of all, has brought off her brood of three
young by the last of April, and now they may frequently be located in the
twilight as they beg for food. Young hairy woodpeckers become noisy in
their nest holes.

May and June are periods of intense activity among the birds of the area
and everything seems to be tense with the pressure of the advance of the
season. Both permanent and summer resident species, having appropriated
their share of the available nesting territory, are absorbed in the task of re-
production and the placing of their young upon a semi-independent footing
in the community. Population density of breeding birds and mammals is at
its maximum by the middle of June. Territory lines have been strictly
drawn until now, but are relaxed as the summer resident birds bring their
young off the nests. This change has already taken place in the case of
most, if not all, of the permanent residents. Young gray squirrels, red squir-
rels, and chipmunks are very noticeable. All hibernators are active and mi-
gration is at a standstill. Food is abundant, and the amount of insects con-
sumed must be enormous. Predators, with their own young to provide for,
are very active. On days when the humidity is high, frogs, salamanders,
snails, and slugs may be found. But this climax of activity quickly passes.

82 Tue CLEVELAND Museum oF NATuRAL History oe

Mortality of young is high, and the moving of the summer bird population
out of the area begins quickly.

3. Aestival aspect. By the 20th of June a change in activities is notice-
able, particularly as regards the bird population, as the summer residents
begin to move. Of these the redstart is the most hurried in its departure,
young and old quitting the area by the end of June, after a stay of but a
little over 60 days. A few redstarts will be seen later but these are prob-
ably transients or delayed nesters. The oven-birds follow closely upon
the heels of the redstarts. The first week in July sees them practically gone.
By the end of July the red-eyed vireo and the wood thrush have moved out.
Certain pairs of birds, unsuccessful in the first attempt to raise a family,
persist through three, or even more trials, thus prolonging the stay of a
small portion of their group through July, or even longer. But by August
most of the summer residents have gone.

By mid-June many bird songs are shortened or greatly modified, and
many species have become quite silent. This is often a period of dry weather.
The pools dry up, the withered plants of May apple and cut-leaved dentaria
lie yellow and prostrate upon the ground, the green carpet of May is re-
placed by one of rich brown as the dead leaves of last autumn are exposed
except where seedling beeches and maples have taken their stand. What
vegetation of herbaceous character remains begins to look tattered and shop-
worn. Forest fruits are developing and squirrels are already cutting down
the unripe beech nuts, hickory nuts, and acrons. Tupelo is shedding
some scarlet leaves. The round-leaved green orchid and the nodding pogonia
belong to the aestival aspect of the forest as they come into bloom at this
time. Purple martins and chimney swifts, hunting above the forest roof,
now testify to the fact that insects are flying overhead in the sunshine. Tufted
titmice may be observed shepherding their families noisily about. A cardinal’s
tail feather on the ground suggests that this is the period of moulting and
aestivation, and shortly chipmunks disappear into their underground quar-
ters. Temperatures are high, the cicadas are noisy, “punkies’” (Culicoides)
become very annoying to humans.

4. Serotinal aspect. From mid-August to late September the forest
seems silent and deserted. Nesting territories are now disregarded and
there is apparent a tendency for birds to travel together in groups. Wander-
ing families of nuthatches, titmice, and chickadees are encountered. If there
are moist places in the woods the woodcock is liable to be found here. Nests
of the paper wasp have now assumed large proportions. As the fruits of
tupelo, hemlock, cucumber, and the oaks develop they are prematurely gath-
ered by blue jays, gray squirrels, red squirrels, and chipmunks. Not only
is there an immense amount of fruiting and seeding of forest trees, but also
of herbaceous plants. Mushrooms become a feature of the aspect, often in

July, 1936 A BrecH-MaApPLE CLIMAX COMMUNITY 83

brilliant colors, and miniature forests of beech drops occupy large spaces
about the bases of the beeches. Again the chipmunks, now emerging from
their period of aestivation, yield to the ecstasy of the spring chorus. The
first migrant birds of autumn—certain warblers, and later, the brown
creeper and the golden-crowned kinglet—appear. Black-throated green war-
blers become briefly abundant beyond the numbers of the summer resi-
dents as the southward movement of the species as a whole begins. An in-
spection of Figure 16 will show that this is a period of low bird population
numbers with the flow of bird life constricted into a narrow channel. But
in September the stream widens and a period of great unrest is ushered in.

5. Autumnal aspect. In late September there are chilly days, and the first
of the winter visitors among the birds appear. By the first week in October
the few lingering hooded warblers and scarlet tanagers have gone, and other
summer resident species are probably represented by late migrating in-
dividuals only. The first robins and thrushes are noted in the woods—the
prophecy of many more to come. October sees great flocks of them—robins
in two great waves, the flocks numbering hundreds—and thrushes—her-
mits first, then olive-backs, veerys, and gray cheeks. They feast upon the
wild grapes, the fruits of tupelo, sassafras, pokeweed, and flowering
dogwood. They also give the floor of the forest a thorough looking over
for beetles, grubs and other insects, as they turn over the dead leaves and
dig into the rich humus. Their stay lasts into November, covering the
period of the great fall of leaves from the deciduous trees. Meanwhile the
winter visitors are increasing in number, and if the red-breasted nuthatch
is present, these numbers may reach considerable proportions. The char-
acteristic winter bird companies are now formed and will keep together
throughout the winter.

Color in the forest in autumn develops later than it does along the road-
sides, and many trees retain their leaves long after the roadside trees are
bare. Elm, tulip, and spicebush begin the process by yellowing early.
October 10th sees the first splashes of real color inside the forest, though it
will be ten days at least before the woods are all red and gold. Robins are
noisy, sounding alarms, calling, and occasionally carolling a bit. Chip-
munks add to the racket, chippering and clucking everywhere, and are very
active about the grape vines. Both red and gray squirrels are vocal. Blue
jays are calling, white-throated sparrows singing in the grape tangles,
nuthatches signaling from nearby trees. The green leaves of wild ginger
are still bright in places where this plant occupies the ground.

By mid-October, though the interior of the forest is still predominantly
green, the tops of the trees show yellow, bronze, and red. The tupelos
are quite red. By October 27th the leaves are about half off the trees, and
now rains and high winds will begin stripping off all those that have loosened

84 THE CLEVELAND Museum oF NATURAL HIstTory Sa. Pee

their grip upon the twigs. In the absence of wind the leaves will fall lazily
by ones and twos. Sugar maples and beeches are the last to surrender
their leaves to the winds and often small beeches will retain their leaves,
dead and brown, throughout the winter. These newly fallen leaves make
a transitory carpet of red, yellow, and brown on the forest floor. With the
falling of the leaves of the primary dominants beech nuts and maple seeds
also are shed in large quantities, and storage activities on the part of chip-
munks, red squirrels, and gray squirrels becomes a major activity. Num-
bers of gray squirrels may increase as individuals from outside the area
come in attracted by the abundance of food. There is liable to be a full
chorus of chipmunk clucking which may be taken up and carried through-
out the entire range of woodland as far as the ear can discern it.

The first week in November sees the forest floor first yellow, then chang-
ing through bronze to brown. There are large open spaces in the forest
roof, and the dark green of hemlocks begins to show in the background as
one faces the areas where the beech-hemlock association has its stand.
Voices of towhee, nuthatch and junco are characteristic of this period, and
bob-whites may come into the deep woods attracted by the beech nut supply.
The trees will be bare by the third week in November. This is still a period
of great activity among birds and mammals, and there are days when they
are very vocal, and when Hyla crucifer adds his voice to the chorus.

6. Hibernal aspect. There is no sharp demarcation between autumnal
and hibernal aspects. Indian summer days may be extended through No-
vember, though snow usually comes before the month is well advanced. Tree
trunks are now a feature of the aspect, the light gray of beech and the
dark brown of sugar maple making a fine contrast. With the coming of
the first real snow-blanket the woods present a record of moving animal life
written upon its white surface. This is one of the characteristic aspects
of winter. At times the tracks of gray squirrels will cover every part of
the area. These animals, with red squirrels and chipmunks, will be noted
abroad throughout the winter, and will write most of the story on the snow.
Tracks of cottontail rabbit, red fox, white-footed mouse, and short-tailed
shrew will be commonly seen. This is the time of hibernation for inverte-
brates and some vertebrates as well. In December, January, and February
the species list of birds is restricted to the permanent resident and winter
visitor groups, with a massing of numbers in December and a low point in
late January.

A feature of the hibernal aspect is made up of the green leaves which
a number of plants carry over winter. Prominent among these is the
hepatica. Others are foam flower, bishop’s cap, wild blue phlox, spring cress,
and some violets, together with christmas fern, spinulose wood fern, margi-
nal shield fern, and shining club moss. The sedge Carex shows green clumps

July, 1936 A BrEEcH-MAPLE CLIMAX COMMUNITY 85

throughout the winter along the edges of the ravines. As the winter pro-
gresses the débris of stored foods appears where it is dug up and consumed
by the squirrels, and one can form a fairly good opinion as to just what
foods are mostly depended upon for winter needs.

Winter in the area under study is a period of high humidity, due to the
fact that snow does not usually stay upon the ground for any great length
of time, and temperatures are frequently above the freezing point. This
means much melting of ice and snow and much standing water in pools. The
atmosphere is often filled with mist and the snow saturated with water.

BEANS AND ANIMALES

The fundamental difference between plants and animals is, of course, that
plants manufacture their own foods out of elemental substances, while ani-
mals do not, but must in the last analysis depend upon the products of plants
for their supplies of food. Seasonal behavior on the part of the animal
population of a biotic community is thus closely correlated with seasonal
changes in plant activities. Aspection, from the standpoint of the animal
population is but a shifting of food supplies—a sort of clearing and resetting
of the table. On the other hand, in their search for and gathering of food,
and through other activities, animals in turn affect plants in various ways.

Seasonal responses of animals to the activities of plants are well illus-
trated in the present study. Such responses may be direct, as when the animal
is directly dependent upon plant materials for food, or indirect, as when the
animal is dependent upon other animals for its food. The following se-
quence of observed events in the area under study 1s illustrative of such re-
lationships.

With the blossoming of the early wildflowers in April winged insects
appear. These are attracted to the pollen and nectar offered by the flowers,
and their activities assist in the cross-pollination of the plants. The phoebe
(a flycatcher) now comes into the woods, feeding upon the flying insects as
an acceptable food supply.

With the swelling of the buds on the forest trees in spring, gray squirrels
climb aloft to sample this new offering of food, and such birds as the purple
finch and the rose-breasted grosbeak make their appearance as consumers of
this plant product.

With the expansion of the leaves on the trees, hatching insect eggs pro-
duce a multitude of caterpillers as consumers of new foliage. With the
appearance of this new food supply for birds, come hosts of migrating war-
blers whose arrival is neatly timed to coincide with the opportunity to glean
many of these minute larvae from the developing foliage. The summer resi-
dent birds, all highly insectivorous, now arrive from their southern winter-

86 THE CLEVELAND MusEUM oF NATURAL HIsTORY ae Pub

ing quarters and replace the early transients as consumers of enormous num-
bers of insects.

With the storage of carbohydrates in roots, tubers, and other under-
ground structures of herbaceous plants, chipmunks begin to nose the ground
and to plow up many of these crisp foods. They also feed upon blossoms
and developing seeds.

With the ripening of forest fruits, birds and rodents become very active
about the bearing trees and vines and lesser growth as they feast upon these
newly offered foods.

With the development of the great forest crop of gilled mushrooms, a
new assembly of insects becomes active as a consumer of this plant product,
and many rodents also seek it out as a new food.

With the falling of nuts and seeds from the trees, activity on the part
of mice and squirrels becomes strenuous as they gather these staple foods for
storage against future needs.

With the arrival of winter inactivity in the plant world the animal pop-
ulation exhibits a number of differing responses to this radical change in
conditions. Some species migrate to other places, some go into hibernation,
some live upon the stored food which they have gathered and laid away,
some increase their resistance to lowered temperatures and go on hunting as
before.

Basically the forest dominants must be considered as the determiners
of the whole complex of life within the range of their influence. They, of
course, depend upon soil and climate for their existence where they are, but
being there, they not only limit and circumscribe the life activities of other
organisms associated with them, but witalize them as well. The limiting
influence of the forest on other organisms is expressed through such things
as occupation of the ground, cutting down of light, increasing relative hu-
midity, reducing rate of evaporation, modifying temperature—matters which
in the present study have been considered under the head of climate. Spe-
cies which are not equipped to live in such an environment are excluded.
The vitalizing influence of the forest is expressed through the production
of stored energy of such quality and quantity, and in such form, as to be
readily available to the animal population as food.

The beech-maple forest thus limits and supports an enormous insect
population which not only consumes vast amounts of plant material, but
which also has many complex interrelations within its own group and with
other animals; a rodent population adapted to the use of beech nuts and
sugar maple seeds; a shrew population that spreads its network of tunnels
beneath the humus for the capture of insects and other prey; a woodpecker-
nuthatch-flycatcher-thrush population adapted to the capture of insects in
many different situations above ground; and a relatively small carnivore

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 87

group which subsists upon the smaller vertebrates. The mammals are pre-
dominantly seed and insect eaters, the birds predominantly insectivorous.
Chains of animals are thus linked together by food, and all dependent in the
long run on plants. Thus we have the concept of the food chain and the
food cycle (Elton 1927).

In addition to an adequate food supply, the numbers of animals to be
found within a forest community are greatly influenced by the facilities
offered for successful reproduction and for protection from enemies. From
the standpoint of birds and mammals this means cover, nesting sites, nest-
ing materials, and satisfactory adjustment to the environment during the
breeding season. It is because the forest under study is rich in these re-
spects that such a large animal population as has been noted at times is
possible.

From the standpoint of the effects of animal activities upon plant life
the fact of outstanding significance is the very large consumption of plant
materials by insects. Not only is the steady consumption of foliage by the
larvae of many species involved, but no part of the plant structure is im-
mune from attack. Buds, leaves, blossoms, bark, sapwood, heartwood, twigs,
leaf petioles, root structures, seeds, juices—all have their specialized groups
of insects adapted to feed upon them, or to utilize some of them for pur-
poses of pupation or hibernation. The effects of such activities on plants
are essentially destructive.

Over against this potentially grave destructive force, and mitigating its
effects in large degree, is the ever-present fact that insects are hunted and
consumed as food by practically the entire bird and mammal population, the
entire spider population, and a considerable group within their own ranks.
It is to this insect-consuming group of animals that the forest owes its con-
tinued existence, for it seems a fair assumption that if the activities of the
birds and mammals and predaceous insects of the forest community were
withdrawn or nullified in some way, the forest would soon be destroyed by
the unchecked ravages of phytophagous insects.

It is true that many birds and mammals are also consumers of buds,
leaves, shoots, bark, and roots of plants. While all of this has its limiting
effect on plant life, it is inconsequential as compared with the effects of
insect consumption of plants or of competition among plants themselves.
The large consumption of seeds by birds and mammals is also inconse-
quential, except possibly in years of low seed production, as seeds are
produced normally in enormous quantities and there is a very large surplus
over and above the needs for reproduction. In fact, with the ever-present
threat of serious injury to the forest dominants through the destructive
activities of insects, the conversion of the surplus seed supply directly or in-
directly into insect-consuming animals appears as a necessary protective

88 THE CLEVELAND Museum oF NATuRAL History oe ‘i Se

measure and a part of the mechanism whereby equilibrium in the community
is maintained.

The animal population of the forest may thus be considered in relation
to its effect upon plant life from two points of view—primarily as a severely
limiting or potentially destructive force, as represented by the phytophagous
insects, and secondarily as a protective and conserving force, as represented
by the predaceous insects, spiders, birds, and mammals. In this connection
it is interesting to consider how largely insects enter into the regular diet of
animals usually classified as more or less strictly herbivorous or carnivorous.

The storage of nuts underground by squirrels has often been referred to
as a kind of “‘planting’’ of seeds, beneficial to the forest, when such seeds are
not later dug up and eaten but are left to sprout. This may be the case in
areas where reforestation is in progress, but in the already established forest
it is negligible as compared to the natural and normal seeding of the forest
trees which is usually far in excess of the need.

An important contribution made by animals to the well-being of the plant
community which should not be overlooked lies in the vast amount of stir-
ring up of the soil that they accomplish. Shrews, mice, moles, and chip-
munks are great tunnelers in soil and humus and dead wood. Many inverte-
brates, like the ants that work in dead wood, the insects that live under dead
bark, earthworms, and many animals of minute size that are active in the
humus (Jacot 1935), all contribute to this result. The plowing of the
ground by red squirrels and gray squirrels as they prosecute their search
for buried food is somewhat in the nature of continuous cultivation, and
there is constantly added from their droppings, and from those of countless
other animals, an enrichment of the soil that in the aggregate must bulk
very large. Some of this stirring up of the soil is of benefit to the more
deeply rooted plants in freeing them from competition with more insecurely
rooted neighbors. Thus the chipmunk, nosing out the tubers of spring beauty
or dwarf ginseng, makes better the conditions for growth for the seedling
beech crowded in among the vigorous herbs.

Because of such interrelations plants and animals form a sociological unit,
the biotic community, making a consideration of either without the other in-
complete.

SUMMARY AND CONCLUSIONS

The subject of the study herein presented is a 65 acre tract of beech-maple-
hemlock forest in the Cleveland, Ohio, Metropolitan Park System. System-
atized work was carried on through regular weekly visits covering a period
of four years. Records of temperature, precipitation, relative humidity,
wind velocity, and evaporation rate were obtained.

July, 1936 A BEEcH-MAPLE CLIMAX COMMUNITY 89

2. Considering the vegetation of the area as a whole, it is evident that
there exist here two rather distinct forest communities ; a beech-maple asso-
‘ciation and a beech-hemlock-oak-chestnut mictium.

3. The beech-maple association represents the climatic climax of the
region. It is mature, vigorous, stable, well established, and occupies 89
per cent of the area. It is characterized principally by the beech and the
sugar maple as primary dominants, with red maple, tulip, white ash, and
northern fox grape as secondary dominants. Shagbark hickory, cucumber,
red oak, and white oak are listed as incidental dominants, and hop hornbeam
and American hornbeam as subdominants. Other subdominant species in-
clude 12 of shrubs, 69 of herbaceous plants, 14 of ferns, 7 of climbing,
twining, or trailing plants, 10 of mosses, and 6 classified as miscellaneous.
Of saprophytic and parasitic plants 247 are listed. Seasonal aspects, in-
cluding the responses of both plants and animals to seasonal changes, are
described.

4. The beech-hemlock-oak-chestnut mictium represents a remnant of
former forest communities now giving place to beech-maple. It is unstable,
lacks vigor, is not well established, occupies 11 per cent of the area. It is
characterized principally by the beech, the hemlock, and formerly the chest-
nut, as primary dominants, with red maple and red oak as secondary dom-
inants. Shagbark hickory, cucumber, tupelo, sassafras, white oak, wild
black cherry, pignut, black birch, and scarlet oak are listed as incidental dom-
inants, and hop hornbeam and American hornbeam as subdominants. Other
subdominant species include 7 of shrubs, 1 of climbing plants, 6 of herbs, and
5 of ferns.

5. One of the primary dominants of the mictium, the beech, represents
the entering wedge of the climatic climax. Another, the hemlock, represents
a more northern forest community left in its present position apparently
as a remnant of the forest which followed the glacial ice in its northward
retreat. In this community the presence of certain subdominants usually
associated with hemlock is noted. The oak-chestnut remnants on the other
hand represent a prominent forest community now to be found in the south-
ern Appalachians.

6. As compared with the plants of the area the animal content presents
a constant fluctuation in numbers, species, and activities. A study of the
vertebrates and some invertebrates discloses the presence of 27 species of
mammals, 83 of birds, 8 of reptiles, 11 of amphibians, and 20 of molluscs.

7. A study of the numbers and distribution of these animals indicates
that all habitats and ecological niches in the area are well occupied when
the population is at its peak, but that great changes in numbers occur both
seasonally and annually. The most abundant mammals were found to be
the short-tailed shrew and the white-footed mouse. Of birds 11 species were

90 THE CLEVELAND Museum oF NATuRAL History see

classed as permanent residents, 8 as autumn and winter visitors, 16 as sum-
mer residents, 23 as transients, and 25 as occasional visitors. The number
of nesting pairs per acre was found to average 2.3 (5.7 per hectare). Of
the reptiles only one, the pilot blacksnake, was found to have important eco-
logical relations. |

8. The constituent animal species, exclusive of invertebrates, classified
on the basis of abundance, activities, and influence in the community were
assigned the following positions: permanent predominants 7, fluctuating
predominants 3, seasonal predominants 15, permanent members 11, fluctuat-
ing members 2, seasonal members 47, incidental members 37.

9. The interrelations between plants and animals are considered, and
the conclusion is reached that a consideration of either without the other is
incomplete.

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