American Elm

American elm
white elm
water elm
soft elm
Florida elm

More info for the term: cover

American elm trees provide thermal cover and nesting sites for a variety
of primary and secondary cavity nesters [26,30].

More info for the terms: forest, fruit, perfect, tree

American elm is a deciduous, fast-growing, long-lived tree which may
reach 175 to 200 years old with some as old as 300 years [5,27,53]. In
dense forest stands, American elm may reach 100 to 200 feet (30-36 m) in
height and 48 to 60 inches (122-152 cm) in d.b.h. Heights of 80 feet
(24 m) are common on medium sites but on very wet or very dry soils, the
species is often 40 to 60 feet (12-18 m) tall at maturity [5,44,54]. In
the forest American elm often develops a clear bole 50 to 60 feet (15-18
m) in length. Open-grown trees fork 10 to 20 feet (3-6 m) from the
ground with several erect limbs forming a wide, arching crown [29,56].
The alternate, double-toothed leaves are 2 to 5 inches (5-10 cm) long
and 1 to 3 inches (2.5-7.5 cm) wide. The dark gray bark is deeply
furrowed (9,15). The perfect flowers are borne in dense clusters of
three or four fascicles. The fruit is a samara consisting of a
compressed nutlet surrounded by a membranous wing [7,29].

The root system of American elm varies according to soil moisture and
texture. In heavy, wet soils the root system is widespreading, with
most of the roots within 3 to 4 feet (1.0 - 1.2 m) of the surface. On
drier soils, American elm develops a deep taproot [29].

The typical variety of American elm (var. americana) is found throughout
eastern North America [5]. Its range extends from southern Newfoundland
westward through southern Quebec and Ontario, northwest through Manitoba
into eastern Saskatchewan, then south on the upper floodplains and
protected slopes of the Dakotas. It is found in the canyons and
floodplains of northern and eastern Kansas and in eastern Oklahoma and
central Texas. American elm is common along the Gulf Coast and east
into central Florida [9,7,29,43].

More info for the terms: fire regime, seed

Fire rarely occurs in the moist areas where American elm typically
grows. When fire does occur and conditions are dry, American elm
greatly decreases following fire [12]. Wind- and water-dispersed seed
are important in the survival of American elm following fire [28].
After being top-killed, young American elm will sprout from the base
following fire [5].

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".

More info for the term: top-kill

Fire is usually not a major management consideration for American elm in
the North, but in the southern bottomlands, fall and early spring fires
are extremely damaging. Most fires will top-kill seedlings and saplings
and wound larger trees, providing an entry point for heart-rot fungi
[20,40].

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Phanerphyte

More info for the terms: cover, swamp

American elm is common on wet flats and bottomlands but is not
restricted to these sites. In the southern bottomland regions, it
commonly occurs on terraces and flats but not in deep swamps. At higher
elevations in the Appalachians it is often limited to the vicinity of
larger streams and rarely occurs at elevations above 2,000 feet (610 m).
In the Lake States and Central States, it is found on plains and moraine
hills as well as the bottomlands and swamp margins. Along the
northeastern edge of its range, it is usually restricted to valleys
along waterways except where it has been planted on the uplands
[29,42,50].

American elm grows best on rich, well-drained loams. Growth is poor on
dry sands and where the summer water table is constantly high. In
Michigan, on loam and clay soils, growth is good when the summer water
table drops 8 to 10 feet (2.4-3.0 m) below the surface. In the South,
American elm is common on clay and silty-clay loams on bottomlands and
terraces. Growth is medium on wetter sites and good on well-drained
sites. In the arid western end of its range, American elm is restricted
to silt or clay loams in river bottoms and terraces. American elm most
commonly grows on soils of the orders Alfisols, Inceptisols, Mollisols,
and Ultisols [5,29,41].

In addition to those species mentioned in SAF Cover Types, common
associates of American elm include balsam fir (Abies balsamea), silver
maple (Acer saccharinum), sycamore (Platanus occidentalis), pin oak
(Quercus palustris), black tupelo (Nyssa sylvatica), white ash (Fraxinus
americana), sweetgum (Liquidambar styraciflua), hackberry (Celtis
occidentalis), boxelder (Acer negundo), birch (Betula spp.), and hickory
(Carya spp.) [4,19,43,50].

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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

16 Aspen
24 Hemlock - yellow birch
25 Sugar maple - beech - yellow birch
26 Sugar maple - basswood
28 Black cherry - maple
39 Black ash - American elm - red maple
42 Bur oak
46 Eastern redcedar
52 White oak - black oak - northern red oak
53 White oak
55 Northern red oak
60 Beech - sugar maple
62 Silver maple - American elm
63 Cottonwood
85 Slash pine - hardwood
91 Swamp chestnut oak - cherrybark oak
92 Sweetgum - willow oak
93 Sugarberry - American elm - green ash
94 Sycamore - sweetgum - American elm
95 Black willow
96 Overcup oak - water hickory
101 Baldcypress
102 Baldcypress - tupelo
103 Water tupelo - swamp tupelo

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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):

FRES10 White - red - jack pine
FRES11 Spruce - fir
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

K093 Great Lakes spruce - fir forest
K095 Great Lakes pine forest
K096 Northeastern spruce - fir forest
K100 Oak - hickory forest
K101 Elm - ash forest
K111 Oak - hickory - pine forest
K112 Southern mixed forest

More info for the terms: severity, top-kill

American elm is easily damaged by fire [11]. Low- and moderate-severity
fires top-kill trees up to sapling size and will wound larger trees
[29]. In a study of the fire effects on 2- to 8-year old American elm
trees in the Missouri prairie, two spring fires of unreported severity
in March and April caused dieback of 40 and 90 percent, respectively
[33].

American elm suffered complete tissue death when the cambium was exposed
to a temperature of 140 degrees Fahrenheit (60 deg C) for 20 minutes
[31].

More info for the term: fruit

Although American elm is not considered a preferred browse, deer,
rabbits, and hares will occasionally browse the leaves and twigs
[24,49]. The seeds are eaten by a number of small birds. The
flowerbud, flower, and fruit are eaten by mice, squirrels, oppossum,
ruffed grouse, northern bobwhite, and Hungarian partridge [5].

More info for the term: tree

Tree

More info for the terms: natural, tree

American elm has suffered greatly since the introduction of Dutch elm
disease from Europe around 1930. Since then the disease has spread over
much of the United States [46,48]. The disease is caused by the fungus
Ceratocystis ulmi. Spores of this fungus are carried by American
(Hylurgopinus rufipes) and European bark beetles (Scolytus multistria)
from diseased trees to healthy trees. The beetles breed only in dead,
dying, or recently cut elm wood and winter as larvae under the bark. In
the spring, adults emerge and fly a short distance (usually less than
500 feet [150 m]) to feed in the twig crothes or small branches in the
upper parts of the living trees. As the beetles feed, the spores are
introduced into the tree and the tree becomes diseased. After the
spores have been introduced into the tree's vascular system, the xylem
becomes plugged and a toxin is produced. The trees wilt on the small
branches and eventually on the whole limbs [16,39,47]. A program for
controlling Dutch elm disease has been described [47].

Most of the genetic research of elm has been concerned with the
resistance of various species, varieties, races, and hybrids to Dutch
elm disease or phloem necrosis. Natural hybridization in American elm
is uncommon, although controlled crosses have been made with Siberian
elm (Ulmus pumila). However, the success of these controlled crosses
has been quite poor [2,29]. American elm is a tetraploid, having 28
chromosomes, while most other elms have 14 chromosomes, making it
difficult to cross with other elms [35].

AL AR CT DE FL GA HI IL IN KS
KY LA ME MD MA MI MN MS MO NE
NH NJ NY NC ND OH OK PA RI SC
SD TN TX VT VA WV WI MB NB NF
ON PQ SK

Before the advent of Dutch elm disease, American elm was prized as a
street ornamental in many cities in North America [55]. The inner bark
of American elm was used in various decoctions by the Native Americans
in the southeastern United States [17].

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More info for the terms: fruit, seed

The time of flowering, seed ripening, and seed fall varies by about 100
days between the Gulf Coast and Canada. The flower buds swell early in
February in the South and as late as May in Canada. The trees are in
flower 2 to 3 weeks before the leaves unfold. The fruit ripens as the
leaves unfold or soon afterward. The seed is dispersed as it ripens and
seed fall is usually complete by the middle of March in the South and by
the middle of June in the North [3,7,29].

Young American elm will sprout from the base following fire [1,25].

The Research Paper by Bowles and others 2007 provides information on
postfire responses of several plant species, including American elm,
that was not available when this species review was originally written.

More info for the terms: secondary colonizer, seed

Tree with adventitious-bud root crown/root sucker
Secondary colonizer - on-site seed
Secondary colonizer - off-site seed

More info for the terms: epigeal, seed, stratification, tree

Seed production and dissemination: American elm seed production may
begin as early as age 15 but is seldom abundant before age 40. When
mature, American elm is a prolific seed producer. Trees as old as 300
years have been reported to bear seed [5]. In closed stands, seed
production is greatest in the exposed tops of trees. The winged seeds
are light and readily disseminated by the wind. Although most seeds
fall within 300 feet (90 m) of the parent tree, some may be carried 0.25
mile (0.4 km) or more. In riverbottom stands, the seeds may be carried
by the water for miles. Cleaned, unwinged seeds average 70,900 per
pound (156,000/kg) [28,46,53].

Seedling development: Germination in American elm is epigeal. Seeds
usually germinate soon after they fall, although some seeds remain
dormant until the following spring. Germination is usually 6 to 12 days
but may extend over a period of 60 days. Dormancy may be overcome by
stratification in sand for 60 days at 41 degrees Fahrenheit (5 deg C).
The seeds germinate best with night temperatures of 68 degrees
Fahrenheit (20 deg C) and day temperatures of 86 degrees Fahrenheit (30
deg C). The germination capacity averages about 65 percent
[7,10,29,46].

Vegetative reproduction: American elm will reproduce fairly vigorously
by stump sprouts from small trees. Large trees 150 to 250 years old
seldom sprout after cutting [29]. Observations in undisturbed
bottomlands of Minnesota suggest that replacement of American elm may be
by root suckering [5].

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This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

16 Upper Missouri Basin and Broken Lands

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More info for the terms: climax, hardwood

Faculative Seral Species.

American elm is classed as intermediate in tolerance among eastern
hardwoods [50]. It usually responds well to release. Once it becomes
dominant in a mixed hardwood stand, it is seldom overtaken by the other
species. It can persist for years as an intermediate but will be
replaced by tolerant hardwoods such as sugar maple (Acer saccharum) or
beech (Fagus grandifolia) if suppressed. Although American elm is not
listed as a key species in the climax types on moist sites, it is
usually one of the associated species [29,32].

The currently accepted scientific name for American elm is Ulmus
americana L. [36]. Recognized varieties include U. americana var.
americana and U. americana var. floridana, which is restricted to the
coastal plains from eastern North Carolina to central Florida [15,27].

American elm can be planted for erosion protection and as a windbreak
[21,38]. Its shallow and widespreading roots make it fairly windfirm
[8,56]. American elm can be propagated by cuttings, but the results
have been variable. Doran [14] reports that cuttings taken in June were
rooted with 94 percent success after treatment with indolebutyric acid
but rooted poorly with no treatment. The propagation of root cuttings
was ineffective for American elm in Ohio [6]. Leafbud cuttings are
superior to soft-wood cuttings for propagating American elm [23].

More info for the term: fuel

The wood of American elm is coarse-grained, heavy, and strong. It lacks
durability, warps, and splits badly in seasoning [44]. The wood is
used in the manufacture of boxes, baskets, crates, barrels, furniture,
agricultural implements, and caskets. Elm veneer is used for furniture
and decorative panels [9,51]. American elm is also used for fuel wood
[13].