Carpinus caroliniana Walter

More info for the term: prescribed fire

The Research Project Summary Effects of surface fires in a mixed red and
eastern white pine stand in Michigan and the Research paper by Bowles and others 2007
provide information on prescribed fire and postfire response of several plant species,
including American hornbeam, that was not available when this species review was written.

American hornbeam
blue-beech
ironwood
muscletree
water-beech

More info for the terms: fruit, tree

American hornbeam is a native, deciduous small tree. It usually grows
30 to 40 feet (9-12 m) tall [4,13,32,39]. The bark is thin, close, and
usually smooth. The trunk is often crooked, and is usually coarsely
fluted, resembling a flexed muscle [4,7,13]. The fruit is a ribbed
nutlet 0.16 to 0.24 inch (4-6 mm) long [3,4]. It is usually described
as slow-growing and short-lived [27].

The largest American hornbeam on record for the Southeast was 75 feet
(22.8 m) tall, 21.6 (54.8 cm) d.b.h., and 67.8 inches (172.2 cm) in
circumference [42].

The range of American hornbeam extends from central Maine west to
southwestern Quebec, southeastern Ontario, northern Michigan, and
northern Minnesota; south to central Iowa and eastern Texas; and east to
central Florida [22].

More info for the terms: fire frequency, fire regime, frequency, swamp, top-kill

American hornbeam is not resistant to fire damage due to its thin bark.
It probably sprouts after top-kill by fire. It occurs mostly in
communities that rarely experience fire.

Florida swamp and hammock communities in which American hornbeam occurs
are estimated as having a fire frequency on the order of one or two
fires per century [8]. Also in Florida, American hornbeam is one of a
number of hardwoods invading longleaf pine (Pinus palustris) communities
in the absence of fire. A community sampled 55 years after the last
recorded fire was dominated by swamp chestnut oak (Quercus michauxii),
American hornbeam, live oak (Q. virginiana), water oak, sweetgum,
eastern hophornbeam, Carolina ash (Fraxinus caroliniana), and pignut
hickory (Carya glabra), with a few remaining large longleaf pine in the
overstory [14].

FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find FIRE REGIMES".

The very hard, dense wood of American hornbeam rots very rapidly;
dying trees usually disappear within a decade [21].

American hornbeam is sometimes present as an undesirable species in
cut-over pine on terrace or terrace-equivalent sites. Burning in late
spring to early winter may be useful for controlling undesirable
hardwoods on these sites, but is effective only during a long dry
period. Fuels are too moist to achieve good fire spread otherwise [34].

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More info for the term: phanerophyte

Phanerophyte

More info for the term: tree

American hornbeam exhibits its best growth on rich, moist soils in
bottomlands, coves, and lower protected slopes. It is also common along
the borders of streams and swamps including bay and river swamps in
Florida [6,8,27], and is also found in hydric hammocks in Florida [8].
The best sites for American hornbeam are characterized by abundant soil
moisture but sufficient drainage to prevent saturation and poor aeration
during the growing season [27]. American hornbeam is primarily found on
poorly to imperfectly drained sites, although it grows on well-drained
sites also [21]. Hook [41] rated American hornbeam as only weakly
tolerant of flooding, although it occurs on sites that have a high
probability of flooding in any given year. He commented that mature
trees remain healthy if flooded less than 24 percent of the growing
season, but are most abundant where flooding occurs 10 to 21 percent of
the growing season [41]. In the Adirondack Mountains, American hornbeam
is found on soils derived from limestone, gneiss, shale, and sandstone
[21]. The usual soil pH range for American hornbeam sites is acidic (pH
4.0-5.6), but the tree can be found on soils as high as pH 7.4 [27].

Maximum elevation for American hornbeam is about 2,900 feet (900 m) in
the southern Appalachians [7]. Its upper elevational range is 3,000
feet (910 m) in the Great Smoky Mountains, but is more common at about
1,600 feet (490 m) [27]. In the Adirondack Mountains, New York,
American hornbeam occurs from 200 to 1,020 feet (60-311 m) elevation [21].

More info on this topic.

This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

More info for the terms: hardwood, swamp

24 Hemlock - yellow birch
25 Sugar maple - beech - yellow birch
26 Sugar maple - basswood
27 Sugar maple
28 Black cherry - maple
39 Black ash - American elm - red maple
44 Chestnut oak
52 White oak - black oak - northern red oak
53 White oak
55 Northern red oak
57 Yellow-poplar
58 Yellow-poplar - eastern hemlock
59 Yellow-poplar - white oak - northern red oak
60 Beech - sugar maple
61 River birch - sycamore
62 Silver maple - American elm
63 Cottonwood
70 Longleaf pine
71 Longleaf pine - scrub oak
73 Southern redcedar
75 Shortleaf pine
76 Shortleaf pine - oak
80 Loblolly pine - shortleaf pine
81 Loblolly pine
82 Loblolly pine - hardwood
83 Longleaf pine - slash pine
87 Sweetgum - yellow-poplar
89 Live oak
91 Swamp chestnut oak - cherrybark oak
92 Sweetgum - willow oak
93 Sugarberry - American elm - green ash
94 Sycamore - sweetgum - American elm
97 Atlantic white-cedar
104 Sweetbay - swamp tupelo - redbay
108 Red maple
110 Black oak

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

FRES12 Longleaf - slash pine
FRES13 Loblolly - shortleaf pine
FRES14 Oak - pine
FRES15 Oak - hickory
FRES16 Oak - gum - cypress
FRES17 Elm - ash - cottonwood
FRES18 Maple - beech - birch

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This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

More info for the term: forest

K098 Northern floodplain forest
K099 Maple - basswood forest
K100 Oak - hickory forest
K101 Elm - ash forest
K102 Beech - maple forest
K103 Mixed mesophytic forest
K104 Appalachian oak forest
K106 Northern hardwoods
K110 Northeastern oak - pine forest
K111 Oak - hickory - pine forest
K112 Southern mixed forest
K113 Southern floodplain forest
K116 Subtropical pine forest

More info for the terms: hardwood, wildfire

American hornbeam is probably either top-killed or killed by most fires.
A wildfire severe enough to kill the hardwood component of a white oak
(Q. alba) stand in Rhode Island eliminated American hornbeam from the
stand. Prior to the fire, American hornbeam comprised 6 percent of the
stems [3].

American hornbeam is of secondary importance to wildlife. Ruffed
grouse, ring-necked pheasant, and northern bobwhite eat small quantities
of the seeds, buds, and catkins. Seeds are consumed by yellow-rumped
warbler [24]. The seeds are also consumed by ducks, but usually only
when acorn production is limited [28]. Seeds, bark, and wood are eaten
by rabbits, beaver, fox squirrel, and eastern gray squirrel.
White-tailed deer browse the twigs and foliage [24]. American hornbeam
has been reported in wild turkey crops from New York and Pennsylvania [6].

More info for the term: hardwood

American hornbeam primarily occurs in the understory of bottomland
mixed-hardwood forests, but also occurs in dry-mesic upland hardwood
forests [27]. Understory associates of American hornbeam in all parts
of its range include eastern hophornbeam (Ostrya virginiana), flowering
dogwood (Cornus florida), sassafras (Sassafras albidum), witch-hazel
(Hamamelis virginiana), serviceberries (Amelanchier spp.), and speckled
alder (Alnus rugosa). In the northern parts of its range, understory
associates include striped maple (Acer pennsylvanicum), mountain maple
(A. spicatum), red mulberry (Morus rubra), pawpaw (Asimina triloba),
serviceberries, and eastern redbud (Cercis canadensis). Southern
associates include magnolias (Magnolia spp.), deciduous holly (Ilex
decidua), American holly (I. opaca), winged elm (Ulmus alata), sweetbay
(Magnolia virginiana), water-elm (Planera aquatica), parsley hawthorn
(Crataegus marshallii), riverflat hawthorn (C. opaca), common persimmon
(Diospyros virginiana), and Carolina laurelcherry (Prunus caroliniana)
[6,27].

More info for the term: tree

Tree

More info for the terms: cover, presence, selection, tree

American hornbeam is usually regarded as a weed tree because of its
small size and poor form [6,27]. In eastern hardwoods, American
hornbeam may increase in dominance on a stand under single tree
selection management [23]. Intensive site preparation is needed to
regenerate intolerant soft hardwoods (eastern cottonwood [Populus
deltoides], sycamore [Platanus occidentalis], sweetgum [Liquidambar
styraciflua], and yellow-poplar [Liriodendron tulipifera]) in the
presence of American hornbeam [15]. American hornbeam initially
dominated a clearcut site but was eventually overtopped by larger
species [2]. American hornbeam may be controlled by 2,4,5-T [6].

Overstory cover is important for maintenance of American hornbeam.
Cutting practices should leave some canopy trees for shade [6].
American hornbeam seedlings grown in full sun responded positively to
increased nutrients (applied at levels to mimic the range of values for
agricultural runoff and sewage sludge) [38].

Insects and diseases are not usually serious problems for American
hornbeam [27].

AL AR CT DE FL GA IN IL IA KS
KY LA ME MD MA MI MN MS MO NH
NJ NY NC OH OK PA RI SC TN TX
VT VA WV WI ON PQ MEXICO

American hornbeam nuts are edible but small and therefore are seldom
collected for food [6]. The leaves of American hornbeam have been used
as an astringent [19].

More info on this topic.

American hornbeam flowers from March 20 to May 6 in the Southeast, and
from April to May in the northern parts of its range, usually before the
leaves are fully grown [27]. The fruits ripen from August to October in
the same season [6,27,39].

More info for the terms: basal area, density, hardwood, headfire, wildfire

In northern Alabama, prescribed fires in a 5- to 6-year-old hardwood
stand (established subsequent to clearcutting) resulted in an increase
in the total number of stems per acre 1 to 2 years after fire. Most of
the increase was attributed to multiple sprouting from existing hardwood
stems that were top-killed by the fire. American hornbeam was listed
with a group of "all others" which numbered 171 stems per acre on the
unburned plot. This group of species averaged 168 stems per acre, 26 of
which were American hornbeam, on burned plots that experienced three
different types of fires: (1) plots burned in spring with a strip
headfire; 72 percent of the area moderately burned, 8 percent lightly
burned or unburned, and 20 percent heavily burned, (2) plots burned in
fall by a slow fire uniformly covering the area, and (3) plots burned in
spring with a moderately intense fire over the entire sampling area
[26].

In North Carolina, a 35-year-old loblolly pine (Pinus taeda) plantation
experienced a wildfire in 1931. When the stand was observed in 1940,
American hornbeam density and basal area were low but similar on three
types of plots: surface burn, crown burn, and unburned [29].

Tree with adventitious-bud root crown/soboliferous species root sucker

More info for the terms: competition, litter, natural, scarification, seed, stratification

The minimum seed-bearing age of American hornbeam is 15 years [32].
Production is greatest at 25 to 50 years and probably ceases at about 75
years [6]. Large seed crops are produced at 3- to 5-year intervals
[27,32]. Seeds are are mainly dispersed by birds, and are wind blown
only a short distance [6,27]. Matlack [25] estimated the lateral
movement of American hornbeam diaspores (nut plus bracts) in a 6 mile
per hour (10 km/hr) breeze as 64 feet (19.4 m). Seed dormancy may be
broken by stratification. Stratification at 40 degrees Fahrenheit (4
deg C) for 18 weeks, stratification plus gibberellic acid, and
scarification of the seedcoat plus gibberellic acid all improve
germination [6,27]. The optimum natural seedbed for American hornbeam
is continuously moist, rich, loamy soil protected from extreme
atmospheric changes [6]. American hornbeam will also establish on leaf
litter seedbeds in deep shade, even when competition is present [27].
Germination occurs from April to June in the spring following seed
maturity [6].

In eastern Texas, seedling survival for American hornbeam is low the
first year, but increases substantially thereafter. Flooding,
drought, damping off, proximity to a conspecific adult, and herbivory
were important causes of first year mortality. Mortality tends to be
concentrated in short periods associated with particular events
(flooding, for example). Periods of reduced flooding allowed American
hornbeam seedlings to increase in importance [36].

Regeneration of American hornbeam after a seed-tree harvest in Arkansas
consisted of new seedlings, advance reproduction, stump sprouts, and
root sprouts [27].

More info on this topic.

More info for the terms: climax, forest, hardwood, natural, seed

Facultative Seral Species

American hornbeam is tolerant of shade [21,27]. It persists in the
understory of late seral and climax communities. Shade tolerance is
greatest in American hornbeam seedlings and declines with age [27].
Curtis and McIntosh [5] rated the climax adaptation of American hornbeam
as 8 (10 is the maximum, usually assigned to species such as sugar maple
[Acer saccharum]). American hornbeam responds positively to overstory
removal. On certain southern sites, it is so aggressive that it
prevents larger species from regenerating after logging or natural
disturbance [27]. In minor streambottoms American hornbeam and other
tolerant subcanopy species are likely to capture a site once the main
canopy is removed [15]. In Connecticut, thinned northern red oak-black
oak-scarlet oak (Quercus rubra-Q. velutina-Q. coccinea) plots had a
higher proportion of American hornbeam and eastern hophornbeam than
unthinned plots [40].

In North Carolina, American hornbeam first appeared in old fields 12 to
18 years after abandonment, and appeared 25 to 40 years after
abandonment on old fields in New Jersey [27]. American hornbeam was
present on 28-, 30-, and 40-year-old old fields in western Tennessee.
It was not present on the 3- and 12-year-old sites [33].

Hupp [17] classes American hornbeam with species that do not normally
invade degraded or newly aggrading substrates (in relation to stream
channelization projects) but are tolerant of bottomland conditions and
have seed that is long-lived (up to 2 years) and dispersed by wind or
water. These species are best suited to establish in bottomlands that
have already been stabilized by pioneer species, and occur in
abundance on undisturbed sites or on sites that are in the later
stages of recovery from channelization [17].

American hornbeam was present in the understory of a mixed hardwood
bottomland forest dominated by water oak (Q. nigra), sweetgum,
cherrybark oak (Q. falcata var. pagodifolia), and loblolly pine (Pinus
taeda). American hornbeam seedlings and saplings dominated the
reproduction layers in this forest [18].

In Florida, American hornbeam tends to capture gaps early, but is
replaced by slower-growing and longer-lived evergreen species such as
American holly and common sweetleaf (Symplocos tinctoria) [30].

The currently accepted scientific name for American hornbeam is Carpinus
caroliniana Walt. (Betulaceae) [3,11,13,22]. Infrataxa are [11]:


Carpinus caroliniana ssp. caroliniana
Carpinus caroliniana ssp. virginiana (Marshall) Furlow

American hornbeam wood is very hard, heavy, and close-grained. It is
very difficult to work and is used only for tool handles, mallets, and
golf club heads [4,6,7].