Main Bulletin of the Torrey Botanical Club The Woody Vegetation of the Mature Forest of the Mianus River Gorge Preserve

The Woody Vegetation of the Mature Forest of the Mianus River Gorge Preserve

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Volume:
94
Language:
english
Journal:
Bulletin of the Torrey Botanical Club
DOI:
10.2307/2483905
Date:
July, 1967
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Torrey Botanical Society
The Woody Vegetation of the Mature Forest of the Mianus River Gorge Preserve
Author(s): Gily E. Bard
Source: Bulletin of the Torrey Botanical Club, Vol. 94, No. 4 (Jul. - Aug., 1967), pp. 336-344
Published by: Torrey Botanical Society
Stable URL: http://www.jstor.org/stable/2483905
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336

BULLETIN

OF THE

TORREY

BOTANICAL

CLUB

[VOL. 94

15. Some poisonous plants in the vicinityof New York. Mo. Bull. Hort. Soc. N.Y. November: 12-16. 1935.
16. Fruits and seeds of common New Jersey trees. Cire. 355. N.J. Agric. Exp. Sta. 1935.
17. Ragweeds and autumn hay fever. N.J. Municipalities 17: 14-15. 1940..
18. Ragweeds-sources of misery.N.J. Agriculture 22: 2. 1940.
19. Botany for the amateur. (This radio script, one of several, was transcribed into
Braille under title, Introduction to botany. See Union Catalog of Hand-copied
Books in Braille.) 1940.
20. Summary of results of seed and legume inoculant inspection for 1940. Inspection
series 1. 1941. (This title was repeated with appropriate date and series number
annually through 1949.)
21. Ragweeds and how to deal with them. N.J. Municipalities 19: 20-21. 1942.
22. Poison ivy. Cire. 482. N.J. Agric. Exp. Sta. 1944. (Revi; sion of Cire. 206.)
23. Poison ivy and its control. Cire. 532. N.J. Agric. Exp. Sta. 1950.
24. Viability of bromegrass seed as affected by dehulling and by storage in fertilizer.
Agron. Jour. 42: 336-337. 1950. (with Gilbert Ahlgren and Alexander
Detgenko.)
The woody vegetation of the mature forest of the Mianus River Gorge Preserve
GILY

E.

BARD1

Department of Biological Sciences
Hunter College in the Bronx, Bronx, N.Y. 10468
BARD, GILY E. (Hunter College in the Bronx, Bronx, New York). The woody vegetation of the mature forest of the Mianus River Gorge Preserve. Bull. Torrey Bot. Club:
94. 1967.-The Mianus River Gorge Wildlife Refuge and Botanical Preserve, near Bedford Village, New York, supports an old, mature forest of hemlocks and mixed hardwoods varying in vegetational composition in the gorge and on the ridge west of the
river. Tsuga canadensis and Fagus grandifolia (51 and 14% respectively of all trees
sampled) are the dominants in the gorge and Tsuga and Betula lenta (44 and 16%
respectively) are the dominants on the ridge. In the Preserve as a whole, the six ranking
species sampled and their importance values are: T. canadensis (103.1), B. lenta (39.5),
F. grandifolia (28.4), Acer rubruim(25.6), Quercus rubra (14.9), and A. saccharum
(10.6). As determinedfromimportancevalues of juvenile stages and young trees (2.5-7.3
cm. dbh) of the arboreseent species sampled, Tsuga will clearly maintain its dominancy
in the near future in the absence of fire,while a reshuffling
of the other ranking species
appears imminent,with A. rubrumand A. saacharum increasing and Q. ruebradecreasing
in importance as hurricanes and windstormsremove senescent individuals. Concordance
of rank in the juvenile stages of Fagus obtains in the gorge, but the future position
of Betula, the ranking sub-dominanton the ridge, is not clear. T-tests reveal statistical
significanceinherentin the differentialdensity in the gorge and on the ridge of seedlings (P<0.001)
of Tsuga and transgressives (P<0.025)
of F?agus, both species more
prominent in the gorge. Seedlings (P<0.005)
and transgressives (P<0.025)
of A.
rubrurm,seedlings of Q. rubra (P<0.050),
and seedlings (P<0.001)
and saplings
(P<0.025)
of Fraxinus americana were denser on the ridge. Of the 48 woocly species
sampled, Viburnum acerifolium and Lindera benzoin, respectively, were the first and
second ranking shrubs.
Near the village of Bedford in New York State, approximately 32 km. north of the
area in Connecticutwhere the Mianus River empties into Long Island Sound is a gorge
(410 11' N, 730 37' 15", W to 410 9' 45" N, 730 36' W; United States Geological Survey
Pound Ridge Quadrangle) postglacially cut by the Mianus at an acute angle to a pre-

' The author wishes to thank Mrs. Gloria A. Anable, Chairman of the Conservation Committee, Mr. James Gibb, Chief Warden-Naturalist, and Mr. Jerald Dulski, Warden-Naturalist, of
the Mianus River Gorge Preserve for helping to expedite the survey reported here. The assistance in the field of Joseph Coppola and Jonathan Stevens is gratefully acknowledged, as is
the preparation of Fig. 2 by Miss Adele Spiegler.

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337

TORREYA

1967]

70
^

+

'
.

_

_s

_

_

.

~~*

-d

Figure 1. A section of the mature forest of the Mianus River Gorge Presei ve ais it
appears onithe ridge above the gorge. The trunikof a large hemlock is visible in. tineleft
foreground flanked to the right by a black birch. The decaying log on the gr-ouiidis
of an 01(1
typical of the numerous chestnut logs found in the forest. Note the reminanits
stoniewvallonceeservinigas a property line. (Phiotographiby Alexander B. Adams).

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338

BULLETIN

OF THE

TORREY

BOTANICAL

CLUB

[VOL. 94

glacial fault in the vicinity (Graham, 1956). Owing to resistant outcrops of Bedford
augen gnieiss,the gorge is precipitouslysteep in a number of places but rarely ranges in
altitude beyonid76.2 m. above sea level at its base to 152.4 m. at its summit. The gneiss
has a general strike of northeast-southwestwith a dip to the north between 50 to 70 degrees (Graham, 1956). The Preserve surrounding the gorge, a tract of 147.8 hectares,
is operated for the Nature Conservancy by the Mianus River Gorge Conservation Commlitteeanid consists largely of a mature forest of hemlocks and mixed hardwoods in the
gorge and onia ridge west of the gorge (Fig. 1).2 The soil is a brown podzolic classified
as a Gloucester stony loam (United State Department of Agriculture, Soil Survey of
the White Plains Area, 1922), and the climate, as measured at Bedford Hills, 129.5 m.
above sea level andl 8.3 km. north of the gorge, is typically humid continental with the
period from May 1 to September 30 essentially frost-free(Nordoff, 1953). No micrometeorological data a-reavailable from the Preserve.
In additiolnto the presence of a number of very old and large hemlocks the Mianus
River Gorge Wildlife Refuge and Botanical Preserve has the distinction of being the
firstNatural Landmark registered by the Department of the Interior under the program
sponsored by Secretary Udall in 1964. While a number of botanists, Doctors H. A. Gleason, William L. Stern, and George K. Brizicky and Mr. Guy Nearing, among others,have
visited the gorge and provided check-listsof the macro- and micro-flora(Mianus River
Gorge Conservation Committee, 1961), no ecological survey of the vegetation was attempted unitil the Chairman of the Conservation Committee, Mrs. Gloria Anable, requested suclhanianalysis of the Preserve. The mature forest of the Preserve is usually considered as an entity,but occurringas it does in two adjacent but topographically-diverse
areas, (1) the steep western (thus east-facing) slope of the gorge and (2) the ridge
above and to the west of the gorge, it was deemed appropriate to investigate the degree
of floristicanid vegetational uniformityin these two sites. Accordingly,in the summer
of 1965, the woody vegetation of the mature forest was surveyed along the length of the
western slope of the gorge (only a small portion of the Preserve lies east of the river)
and its surmounitingridge. The gorge gives relatively little indication of disturbance
at present,but the ridge, which flattensout to a plateau here and there cultivated outside
the Preserve, has been variously exploited until relatively recently,for one can still see
stone walls markinigpropertylines, an abandoned mica quarry, and considerable vegetational evideniceof disturbanieeindicating clearing and grazing.
Methods. Throughout the Preserve, along two lines mainly 20 m. away from and
parallelilnga. major foot-trail,50 quadrats 40 m. apart and 100 square meters each were
surveyed foi trees. Half the quadrats were on the upper slopes of the gorge and half
were on the ridge. Tranigressives,saplings, and seedlings were studied in nested quadrats
within each large quadrat.3 Altogether,50 quadrats of 20 square meters each were used
to canvass the tranisgressivesand saplings and 200 square-meterquadrats were similarly
used for seedlings. From the census of the trees, the relative frequency,relative density,
and relative basal area of eaeh species were computed and then summed to provide the
importanicevalues used in ranking the species of trees, as described in Brown and Curtis
(1952). In the case of the juveniles, relative frequencyand relative density were totalled
to determinlethe importanieevalues and the relative rank of the species of transgressives,
saplings, anid seedlings. In addition, intercept-linestotalling 620 meters were laid from
the westerinbank of the river to the upper slope of the gorge and then to the ridge above
in seven widely-separatedareas to determinethe coverage of shrubs and juvenile arboreseenitindividuals. The importance values and derived ranks of these species were obtained by adding the relative frequeney and relative coverage of each. Nomenclature
used follows that of Fernald (1950).
2 A recently-acquired tract of 55.5 hectares in Connecticut, south of the southern portion of
the Preserve in New York State, was not included in the current study.
3 Seedlings are here considered as young arborescent individuals no more than 0.3 m. tall ;
saplings as 0.3-0.9 m. tall; and transgressives as 0.9-3.6 m. tall but never exceeding 2.5 cm.
in d.b.h. (diameter at breast height, 137 m. above the ground). A tree is here defined as an
arborescent individuial with a trunk exceeding 2.5 cm. d.b.h.

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CANADENSIS
T"ISUGA

A

9

LENTAI?
BETULA

~~~~~~~~~~~~~~~~~~~~~~~~~~~k10

FAGUS
FOLIA
GRAND!

DENSITY
?0/RELATIVE
8-

% Relative
Basal Area

;

1612 8 4

Rank: Ist rd57t9t

)t

RUBRUM
ACER

A
B

Relative
Frequency

RI

c

N

QUERCUS
RUBRAJ-

SACCHARUM

Figure 2. Phytographs of the six ranking arboreseent species growing in the gorge
(dotted) line) and on the ridge (solid line) of the Mianus River Gorge Preserve. In the
case of each species, the relative basal area, relative density, and relative frequency are
indicated in addition to the relative rank among all species of its seedlings and saplings
(A), transgressives (B), trees 2.5-14.7 cm. dbh (C), trees 15-29.7 cm. dbh (D), and
trees 30 or more em. dbh (E). For example, Fagus grandifolia in the gorge has a relative basal area of 15.6%, a relative density of 14%, and a relative frequency of 13%;
on the ridge, its relative basal area is 3%, its relative density is 5.5%, and its relative
frequencyis 3.8%. Of all seedlings and saplings, beech ranks 4th in the gorge and more
than 9th on the ridge; beech transgressivesrank 2nd in the gorge and 7th on the ridge;
the smallest beech trees (C) rank 2nd in the gorge and 4th on the ridge; mid-size beech
trees (D) rank 4th both in the gorge and on the ridge; and the largest-size beech trees
(E) rank 2nd in the gorge and are absent on the ridge.

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1967]

TORREYA

341

Results. Thirty-fivearborescent species were sampled in the present survey, more
than half of which were represented by trees with diameters in excess of 15 cm. The
five species exhibiting the greatest girth are hemlock, Tsuga canadensis (98.25 cm.
d.b.h.); white oak, Quercus alba (67.625 cm. d.b.h.) ; red oak, Q. rubra (66.75 cm.
d.b.h.); chestnut oak, Q. prinus (65.25 cm. d.b.h.); and beech, Fagus grandifolia (55.25
cm. d.b.h.). Spot measurementsrevealed that the tallest trees are over 30 m.; two of
these encounteredwere a hemlock (32.6 m.) and a black oak, Q. velutina (31.47 m.). A
dead, prone hemlock,typical of the fallen trees in various stages of decompositionfound
on the forest floor,measured 28.24 m. long and 54.75 cm. d.b.h. Tree-ring analysis of a
core taken from one of the largest living hemlocks in the Preserve indicated that these
trees are about 300 years old (Stern, 1967, private communication).
In the areas surveyed,the gorge supports 20 arborescent species 50% of which are
represented by trees over 30 cm. d.b.h., a group constituting 9.8% of the 346 trees
sampled. On the ridge, 24 arborescent species were encountered,but only 33.3% of them
are trees over 30 cm. d.b.h., and these comprise only 5.2% of the 363 trees sampled. The
basal area per square meter of gorge occupied by trees over 2.5 cm. d.b.h. is 32.64 cm.2;
on the ridge, it is 23.54 cm.2. Table 1 and Fig. 2 may be consulted for a comparison of
the relative importance of the various arborescent species. Table 1 considers the mature
forest as an entity,as it appears to the casual visitor to the Preserve. Fig. 2 analyzes
the differentialimportance of the six major species in the gorge and on the ridge.
Approximatelyhalf of all the trees sampled are hemlocks (51% in the gorge; 44%C
on the ridge), and this is the dominantspecies in most of the stages encountered (Table 1
and Fig. 2). Hemlock trunksin excess of 2.5 cm. d.b.h. occupy on the average 12.13 cm.2
of surface area per square meter of gorge and 7.03 cm.2 per square meter of ridge. The
second ranking species in the Preserve as a whole is black birch, Betula lenta, but in the
gorge, beech is the ranking sub-dominant.On the ridge, the density of black birch is
of the trees on the ridge but
16.2%; in the gorge it is 9.8%. Beech comprises 5.5%Z10
14.2% in the gorge (Fig. 2). Beech is the second ranking species in the gorge of the
saplings, transgressives, and trees sampled in quadrats and juveniles intercepted by
lines, but in 1965, its seedling production was exceeded by red maple (Acer rubrum),
mountain laurel (Kalmia latifolia), sugar maple (A. saacharum), and floweringdogwood (Cornus florida).4 On the ridge, there is less concordance of rank in the various
arborescent stages. Hemlock is dominant amongst trees and transgressives,but saplings
of ash (Fraxinus americana) are more numerous than those of hemlock, and in 1965,
hemlock seedlings were ninth of eleven ranks occupied by 17 sampled species. It is
difficultto determinethe single, second-rankingspecies among the juveniles on the ridge:
of the youngest trees, it is black birch; of the transgressives,it is red maple; of the
seedlings, it is ash.
Species omitted from Table 1 are as follows with their respective ranks in parentheses: among seedlings, Kalmia latifolia (6), Lindera benzoin (7), Betula popultifolia
(13), Prunus serotina (14), and Quercus palustris (16); among saplings, Lindera (4),
Kalmia and Ostrya virginiana (11); among transgressives,Lindera (5), Castanea dentata (12), Kalmia, Prunus, and Pinus strobus (13); and among intercepted juveniles,
Castanea (9), Q. palustris (11), Prunus (13), and B. populifolia (14).
Juveniles generally occupy about 22.2% of the soil with hemlock exhibiting the
greatest average coverage (9.6%) and being well-representedat all elevations. Beech
juveniles average 4.3% and are best representedon the upper slopes of the gorge. The
distributionof juveniles of black birch is discontinuous and may be correlated with rock
outcroppings.In the Preserve as a whole, the paucity of young oaks is obvious (Table 1).
The differentialdensity in the gorge and on the ridge of the various stages of the
major arborescent species as subjected to a T-test (Snedecor, 1956) indicate that hemare significantlydenser
and beech transgressives (P<0.025)
lock seedlings (P<0.001)
and seedlings
in the gorge than on the ridge. Red maple transgressives (P<0.025)
The classification of the juvenile stages of beech is based on size, not origin; root sprouts
are included, but no sprouts were censused which were discovered growilag within a 30 cm.
radius of a trunk.

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342

BULLETIN

OF THE

TORREY

BOTANICAL

CLUB

[VOL. 94

and saplings
and ash seedlings (P<0.001)
red oak seedlings (P<0.050);
(P<0.005);
are significantlydenser on the ridge than in the gorge. In no case was there
(P<0.025)
a significant differentialdensity of mature trees per given species, but the greatest
differences(P<0.100) is noted in the case of beech which exhibits a density in the gorge
about 21/2times greater than that on the ridge.
The 12 ranks of importance values (totalling 199.5) of the 15 species of shrubs and
woody-vinessampled with line-interceptsare as follows: 1: Viburnum acerifolium, 68.3;
2: Lindera benzoin, 44.0; 3: Mitchella repens, 29.0; 4: Kalmia latifolia, 10.7; 5: Rhus
radicans, 10.1; 6: Rhododendron nudiflorum,9.2; 7: Corylus americana, 8.4; 8: Parthenocissas qiminquefolia,5.8; 9: Gaultheria procumbens, 2.6; 10: Vacciniumnvacillans,
2.4; 11: Smilax rotundifolia,2.2; 12: Chimaphila umbellata, Clethra alnifolia, Lonicera
morrowi,and Lyonia ligustrina, 1.7. Collectively,these species cover on the average only
6.7%o of the ground, with Viburnum the most prevalent (frequency, 45%o; coverage,
2.9%) at all elevations but especially above 122 m. Mitchella is second in ubiquity (frequency, 42%) and Lindera is second in coverage (2%). The latter parallels the altitudinal distribution of juvenile black birch, but it may be associated with ledges of
subsurface rock capable of trapping water. The anomalous, contiguous distribution of
xeric and mesic species in the Preserve may be due to this phenomenon.
Discussion. The Mianus River Gorge Wildlife Refuge and Botanical Preserve consists of a mature forest of hemlocks and mixed hardwoods, presumably a portion of the
Oak-Chestnut Forest Region as mapped by Braun (1950). Topographic differencesbetween the gorge and the ridge account for both vegetational and historic factors operating in the Preserve. The gorge, beinigsteep, is fairly inaccessible and thus has sustained
a minimumof disturbance in most of its area with perhaps only occasional removal of
isolated trees within the past few centuries. The ridge, on the other hand, more accessible
and abutting as it does on an arable plateau, was cleared and then grazed after abandonment therebyproducing a younger forest richer floristicallyand vegetationally than its
counterpartin the gorge. The marks of disturbance in the ridge forest, in addition to
the stone walls and the abandoned quarry, are grassy patches, woody and herbaceous
species of secondary seres, and numerous trunks bifurcated about a meter above the
ground and thus indicating grazing in the past.
The Preserve in effectconsists of two forests on two differentbut contiguous sites:
the older, more stable forest in the gorge and the younger less stable forest on the ridge.
While the forest in the gorge cannot be compared to the Colebrook forest of huge hemlocks and mixed hardwoods which Nichols (1913) described, its oldest trees are a minimum of 300 years, and it possesses the major properties characteristicof a self-perpetuating forest: 1) there is a relatively rich assortmentof arborescent species; 2) 16 species
have boles exceeding 25 cm. d.b.h.; 3) the trees exhibit a wide-variety of age-classes;
4) about 10% of the trees have boles exceeding 30 cm. d.b.h.; 5) there is concordance of
rank in most age-classes; and 6) there is demonstrablereproductionof the primary and
secondary dominant species.
While it is unassailable that the forest in the gorge is more stable than its counterpart on the ridge, it is also obvious that there is no statistically-significantdifferential
density exhibited by the mature trees of the dominant species, although there may be
a vegetationally-significantdifferencein the case of beech. The statistically-significant
distribution of the immature stages of certain species (hemlock, beech, red maple, red
oak, and ash) reflectsvariation in the two sites perhaps in canopy closure and/or moisture contentof the soil, but the lack of significancein the case of the distributionof the
mature trees vitiates the importance of these differences.Equating statistical significance with biological significanceis patently unsound, but one recognizes that the forest
supported by the ridge and plateau is floristicallylittle differentfrom that in the gorge
but vegetationallymore so. It may be concluded that the two topographic phases may be
explained in terms of the continuum theory of communitydevelopment (Brown and
Curtis, 1952). Uninvestigated conditions in the gorge-presumably relating to a higher
percentage of atmospheric and soil moisture-favor the germination and ecesis of certain species (e.g. hemlock and beech) more so than on the ridge and vice versa (black

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1967]

TORREYA

343

birch and red maple). There is, however,sufficientoverlap of the actual range of these
critical factors and the genetically-inheritedpatterns of tolerance to them on the part of
the major species so that none of the latter are restrictedto the gorge or the ridge but
are found throughoutthe Preserve. When interpretedin terms of the continuumtheory,
the two forests merge into the single forest confrontingthe visitor, but the implications
of the existence of the two topographic phases should not be ignored. Until erosion and
deposition obliterate the topographic distinctionsin the Preserve, the major site of ecesis
of each of the species may be considered a generative nucleus from which local dissemination of the population may occur. For example, a rich component of hemlock in the
gorge might ensure its presence in variable concentration on the ridge. Thus, as time
passes, the close proximityof the two phases should engender a decrease rather than an
increase in the vegetational differencesbetween them.
To determinethe future composition of this dual-forest,one must examine the various classes of juveniles and trees smaller than 15-22.3 cm. d.b.h., for the rank of the
latter group conformsbest (80%) to the over-all current rank of all the trees sampled
in the Preserve. Of the remaining six sets of data available for consideration, seedlings,
saplings, transgressives,interceptedjuveniles, trees 2.5-7.3 cm. d.b.h., and trees 7.5-14.7
cm. d.b.h., it is apparent that variable conformityexists in the rank of any given species
in these classes. Hemlock, for example, is firstin fiveof the six classes. Beech is of equal
or successive rank in five,and black birch, red maple, and sugar maple are of equal or
successive rank in three. Of the fivecurrentdominants,only red oak exhibits a total lack
of conformitybetween its rank in these classes and its over-all rank, a condition shared
by most of the other oaks as well.
An imminentshifting in rank of the oaks is revealed in Table 1. Red oak, which
occupies the fifthof 24 ranks of trees, is (together with Carya cordiformnis)the last of
15 ranks of interceptedjuveniles, the last of 13 ranks of transgressives,and the last of
11 ranks of saplings. While red oak holds the ninth of 16 ranks of seedlings, this may be
misleading owing to a lack of consistency in annual seed productioii and ecesis. Of
greater relevance, is the fact that it is last (together with floweringdogwood) of the 12
ranks of the youngest trees (2.5-1.3 cm. d.b.h.) in the Preserve. White and chestnutoaks
are reproducing poorly, but they are represented as juveniles. Black and scarlet oak,
Q. coccinea, appear moribund as species, for in both cases, they are represented only by
large, old trees. Although highly-desiredlife-tables for these plants are not available, it
seems that the most viable species, like hemlock and beech, exhibit a proportionate decrease in the representation of successively older and larger trees, with the youngest
(2.5-7.3 cm. d.b.h.) constitutingno less than half the density of all the trees of a given
species (Table 1). Whether the inability of the oaks to reproduce in quantity is due to
prolonged fireprotection-as is frequentlyproposed-or to a climatic change, or to an
of predators capable of curtailing the density of animals which eat acorns,
insufficiency
or to some other factor or combination of factors has not been experimentallydemonstrated.
With an anticipated loss in importance of the oaks in the next few cenituriesas
windstormsand hurricanestopple the senescent individuals, it is expected that the maples
may be elevated in rank, for they now hold the third rank in the largest size-classes they
have attained in the sampled areas: 37.5-44.7 cm. d.b.h. in the case of red maple and
22.5-29.7 cm. d.b.h. in the case of sugar maple. The gradual aseendancy over the oaks
of sugar maple, either alone or in the company of hemlock,has been noted over much of
the Oak-ChestnutForest Region. Working in northernNew Jersey, Buell et al (1966)
discovered that sugar maple is the dominant species of climax forests on land no longer
subject to erosion. Hemlock, alone or with sugar maple, is the dominant species of climax
forests in cool, moist areas such as ravines still undergoing erosion; once peneplanation
is effected,the sugar maple will pre-emptthe hemlock. This may eventually occur in the
Mianus River Gorge Preserve, but while the gorge remains intact and protected from
fire, the hemlock should endure. Its thermal requirements for breaking post-shedding
dormancyprior to germination are amply met in the Preserve: one month of temperatures below 17?C regardless of the photoperiod obtaining (Stearns and Olson, 1958).

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344

BULLETIN

OF THE

TORREY

BOTANICAL

CLUB

[VOL. 94

With occasional openings due to windstorms or hurricanes, ecesis is enhanced (Winer
and Childs, 1956), and when mature, its capacity for growth and competitive ability
(Winget and Kozlowski, 1965) are such that its present dominance in the gorge and on
the ridge west of the gorge is not threatened. If the climate remains fairly stable, one
can with impunitypredict that as long as the gorge remains basically uneroded and yet
undisturbed, a forest of hemlock and mixed hardwoods should prevail in the Preserve
but with some change in the relative rank of the hardwoods.
Literature Cited
E. Lucy 1950. Deciduous Forests of Eastern North America. Blakiston Co.,
Philadelphia.
BROWN, R. T. and J. T. CURTIS. 1952. The upland conifer-hardwoodforests of northern
Wisconsin. Ecol. Monogr. 22: 217-234.
1966. The upland
BUELL, M. F., A. N. LANGFORD, D. W. DAVIDSON, and L. F. OHMANN.
forest continuumin northernNew Jersey. Ecology 47: 416-432.
FERNALD, M. L. 1950. Gray's Manual of Botany. 8th Edition. American Book Co., N.Y.
GRAHAM J. 1956. Geologic investigation of the Mianus Gorge. Unpublished report of the
New York State Museum and Science Service, Albany; available at the Mianus
River gorge Wildlife Refuge and Botanical Preserve.
Mianus River Gorge Conservation Committee of the Nature Conservancy. 1961. Flora
and Fauna of the Mianus River Gorge Wildlife Refuge and Botanical Preserve.
2nd Edition.
G. E. 1913. The vegetation of Connecticut. II. Virgin forests. Torreya 13:
NICHOLS,
199-215.
NORDOFF, R. 1953. The climate of New York State. Cornell Extension Bull. 764. Original
printing 1949.
SNEDECOR, G. 1956. Statistical Methods. Iowa State College Press, Ames. p. 46.
1958. Interactions of photoperiod and temperature affecting
STEARNS, F. and J. OLSEN.
seed germinationin Tsuga canadensis. Am. Jour. Bot. 45: 53-58.
1956. An old-growthhemlock stand. Conn. Arboretum Bull.
WINER, H. and E. CHILDS.
No. 9: 29-32.
1965. Seasonal basal growth area as an expression
WINGET, C. H. and T. T. KOZLOWSKI.
of competitionin northernhardwoods. Ecology 46: 786-793.
BRAUN,

FIELD TRIP REPORTS
March 19. St. John's in the Wilderness. The annual walk in Rockland County ending in time for the three o'clock church service at St. John's in the Wilderness was held
as usual. However, the snow of two days before and the extremecold in the early morning reduced our attenidanceto three. The snow made walking difficultand left little to
be observed on the ground but tracks of deer, squirrels,and mice. But the sky was beautifullyclear and of a deep blue color one seldom sees. Most of the woods was surprisingly
quiet with only an occasional call of a crow or jay. Another group reported having seen
the pileated woodpecker,but we were not that fortunate.Our group did not venture far
up the trail. Other hiking groups turned out better than might be expected, but the
church was not quite as full as sometimes.The ladies of the church provided even more
abundant refreshments,for which we were all very grateful. Harold H. Clum.
April 16. Olmstead Trail, Staten Island, N.Y. Torrey Club memberswere joined by
eleven Woodland Trail Walkers. The Olmstead Trail is a proposed hiking trail and
bridal path in the N.Y.C. Park System. Another suggestion in the area is the Richmond
Parkway, which would ruin this wooded area with its many scenic views. We saw pussy
willows, spicebush, red maple, American elm, high-bush blueberry, and colt's foot in
bloom. Most of the rest of the plants were still in their winter appearance. However,
birds felt differentlyabout the season: there were many ruby-crownedand goldencrowned kinglets, many yellow palm warblers, some myrtle warblers and one prairie
warbler. Two ospreys soared overhead on their migration north,and a phoebe dipped for

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