Shagbark Hickory

In an oak-hickory stand in southeastern Missouri, most hickories were
top-killed by a wildlfire [38]. Fire-caused mortality of shagbark
hickory can be predicted using a mathematical model [39].

More info for the term: hardwood

Postfire origin of hickory ingrowth following a late summer fire in a
Connecticut mixed hardwood stand was 105 sprouts and 162 seedlings per
hectare in burned areas, compared to four sprouts and nine seedlings per
hectare in unburned areas. Hickories of sprout origin represented 31
percent of stems of all species on unburned plots and 39 percent on
burned sites [60].

shagbark hickory
shellbark hickory
scalybark hickory

More info for the term: cover

Shagbark hickory presumably provides cover for a variety of birds and
mammals and are probably used as den trees by squirrels [11].

More info for the terms: fruit, monoecious, tree

Shagbark hickory is a medium to large deciduous tree which commonly
grows to 60 or 80 feet (20-25 m) in height and up 20 inches (51 cm) in
diameter [21,29]. On favorable sites, trees may grow to 131 feet (40 m)
or more in height and reach up to 9 feet 8 inches (295 cm) in diameter
[57]. Open-grown plants are characterized by an oblong crown, whereas
those growing in forested areas tend to have a straight, slender
columnar crown [29]. The shaggy gray bark exfoliates in long platelike
strips [2,24,57]. Shagbark hickory has a deep taproot [29].

Shagbark hickory is monoecious [54]. Staminate flowers are borne on
long-stalked catkins at the tip of old wood or in the axils of the
previous season's leaves [23,24,54]. Pistillate flowers occur in short
terminal spikes [23,54]. The fruit is a smooth, globose or subglobose
nut [46]. Nuts are borne singly or in clusters of two or three [24].

Shagbark hickory occurs throughout most of the eastern North America but
is largely absent from the southeastern and Gulf coastal plains and the
lower Mississippi Delta. It is found from southeastern Nebraska and
southeastern Minnesota eastward through southern Ontario and Quebec to
Maine and extends southward to Georgia, Alabama, Mississippi, Louisiana,
and eastern Texas [23]. Disjunct populations have been reported in the
mountains of northeastern Mexico [23,36].

The variety ovata encompasses most of the species' range and grows
westward to southeastern Missouri and eastward to Louisiana. The
variety australis occurs in southeastern North America [36].

More info for the terms: density, fire frequency, fire regime, fire suppression, forest, frequency, root crown, tree

Periodic fires tend to favor oak over over the less fire-resistant
hickory. The slow-growing, thin-barked shagbark hickory is reduced by
short fire intervals [33]. Frequent burning at prairie margins reduces
or eliminates shagbark hickory seedlings [33].

Fire suppression in parts of the Northeast has reduced fire frequency
and converted oak-hickory forests to more mesophytic stands [60].
However, in an oak-hickory forest in Indiana, fire suppression since
1917 has contributed to the recruitment of shagbark hickory, sugar
maple, white ash (Fraxinus americana), and American elm (Ulmus
americana) [45]. Increases in tree density in oak-hickory forests in
Michigan have also been attributed to fire suppression [10]. In the
Great Smoky Mountains, fire suppression since 1940 has allowed hickories
to reach fire-resistant size [28].

Shagbark hickory usually sprouts from the root crown or stembase after
abovegrund foliage is killed by fire. Seedling establishement may also
occur.

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".

Scattered surviving hickories often develop large crowns and exhibit
good nut production after fire. These trees may be particularly
valuable for many wildlife species.

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More info for the term: phanerophyte

Phanerophyte

More info for the term: swamp

Shagbark hickory is most commonly associated with upland slopes in the
North, and with river bottoms and coves in the South [23]. It also
grows on the lower slopes of wooded bluffs, in ravines, valleys, and at
the edges of swamps [21,29]. Shagbark hickory generally occurs as
scattered individuals or in small groups but rarely forms pure stands
[2,51].

Plant associates: Shagbark hickory occurs as a principal dominant in
drier parts of the upper Midwest with oaks (Quercus spp.) and other
hickories. [59]. It also grows as aminor component in bur oak (Q.
macrocarpa), chestnut osk (Q. prinus), white oak (Q. alba)-black
oak-northern red oak, pine (Pinus spp.)-oak-sweetgum (Liquidambar
styraciflua),loblolly pine (Pinus taeda)-hardwood, and swamp chestnut
oak (Quercus prinoides)-cherrybark oak (Q. falcata var. pagodaefolia)
[23]. Many oaks, including white oak, northern red oak, black oak,
northern pin oak (Quercus ellipsoidalis), southern red oak (Q. falcata),
chinkapin oak (Q. muehlenbergii), bur oak, and other hickories are
generally prominent overstory associates [1,23,59]. Red maple (Acer
rubrum), sugar maple (A. saccharum), hophornbeam (Ostrya virginiana),
shortleaf pine (Pinus echinata), American basswood (Tilia americana),
redbud (Cercis canadensis), and sourgum (Nyssa sylvatica) also commonly
occur with shagbark hickory [2,48].

Understory associates are numerous and varied throughout the species'
range. Raspberries and blackberries (Rubus spp.), blueberries and
huckleberries (Vaccinium spp.), rhododendron (Rhododendron spp.),
serviceberry (Amelanchier spp.), gooseberries (Ribes spp.), hawthorn
(Crataegus spp.), hazel (Corylus cornuta), muscadine grape (Vitis
rotundifolia), common greenbrier (Smilax rotundifolia), western
snowberry (Symphoricarpos occidentalis), common witch-hazel (Hamamelis
virginiana), wild ginger (Asarum caudatum), nettle (Urtica spp.), and
Canada beadruby (Maianthemum canadense) are important understory
components in many areas [2,3,9].

Climate: Shagbark hickory grows across a wide range of climatic
conditions but grows best in a humid climate. It can survive
temperature extremes of -40 degrees F (-40 deg C) and 115 degrees F (46
deg C). Growing season length varies from 140 days in the North to 260
days in the South [23].

Soils: Shagbark hickory reaches greatest abundance on deep, rich, moist
soils [29,42]. It occurs on soils derived from a variety of sedimentary
and metamorphic parent materials and grows across a wide range of soil
fertility conditions [23]. It appears to be tolerant of soils with high
concentrations of lead and zinc [6]. In Arkansas, it is common on
clayey soils derived from Mississippian and Pennsylvanian shales [23].

Elevation: Shagbark hickory generally occurs at high elevations in much
of the North [42]. It typically occurs below 3,000 feet (910 m) in the
foothills of West Virginia [15]. In the Blue Ridge Mountains of North
and South Carolina, it occurs up to 3,000 feet (910 m) and in northern
Arkansas at elevtions below 2,000 feet (610 m) [23].

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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

21 Eastern white pine
42 Bur oak
43 Bear oak
44 Chestnut oak
45 Pitch pine
51 White pine - chestnut oak
52 White oak - black oak - norther red oak
53 White oak
57 Yellow poplar
59 Yellow poplar - white oak - northern red oak
60 Beech - sugar maple
64 Sassafras - persimmon
65 Pin oak - sweet gum
75 Shortleaf pine
76 Shortleaf pine - oak
78 Virginia pine - oak
80 Loblolly pine - shortleaf pine
81 Loblolly pine
82 Loblolly pine - hardwood
87 Sweet gum - yellow poplar
91 Swamp chestnut oak - cherrybark 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):

FRES10 White - red - jack pine
FRES13 Loblolly - shortleaf pine
FRES14 Oak - pine
FRES15 Oak - hickory
FRES16 Oak - gum - cypress
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

K081 Oak savanna
K089 Black Belt
K100 Oak - hickory forest
K102 Beech - maple forest
K103 Mixed mesophytic forest
K111 Oak - hickory pine forest

More info for the terms: fire intensity, top-kill, tree

All sizes of shagbark hickory are susceptible to damage by fire [20].
However, trees less than 10 inches [25 cm] in d.b.h. tend to be more
susecptible to damage or mortality than trees larger than 10 inches
d.b.h. [53,60]

The effect of fire on hickories varies with topography, slope, aspect,
season of burn, and fire intensity [37]. Light fires commonly top-kill
sprouts and seedlings but leave underground portions undamaged [23].
Hot fires often kill or damage even large trees [23]. Trees are
generally less severely damaged if burned while dormant [37].

The tight, solid bark of hickories is more susceptible to fire-scarring
than is the rough or corky bark of other species [31]. Fire-scarred
hickories are susceptible to rot [23,42], which can ultimately kill the
tree.

More info for the term: mast

Browse: Shagbark hickory is seldom browsed by deer unless preferred
foods are limited or unavailable [23]. It is browsed by livestock only
when other food is scarce.

Nuts: Shagbark hickory nuts are readily eaten by a wide variety of
birds and mammals. The black bear, red fox, gray fox, white-footed
mouse, eastern chipmunk, and rabbits eagerly feed on the nuts [23].
They are a preferred food of the fox squirrel during August, September,
October, February, and March [52], and in some areas, hickory nuts
comprise 5 to 10 percent of the eastern chipmunk's diet [23]. Black
bears consume large quantities of hickory nuts during the fall in parts
of New England. The abundance of mast crops such as acorns and hickory
nuts can affect black bear reproductive success during the following
year [18].

Many birds, including the mallard, wood duck, northern bobwhite, and
wild turkey, feed on shagbark hickory nuts [23]. The ring-necked
pheasant, common crow, bluejay, white-breasted nuthatch, red-bellied
woodpecker, and yellow-bellied sapsucker also consume hickory nuts [41].

More info for the terms: association, codominant

In certain floodplain communities, shagbark hickory grows as a
codominant with black oak (Quercus velutinus), green ash (Fraxinus
pennsylvanica), and northern red oak (Quercus rubra). Shagbark hickory
is included as a codominant or indicator in the following community type
(cts) and plant association (pas) classifications:

Area Classification Authority

IL general veg., cts Thomson and Anderson 1976
NE general veg., cts Aikman 1926
NE, KS general veg., cts Weaver 1960
NE, KS general veg., cts Weaver and Albertson 1945
OH general veg., cts Hamilton and Limbird 1982
sw OH general veg., pas Braun 1936

More info for the term: tree

Tree

More info for the term: mast

Insects/diseases: Shagbark hickory is susceptible to numerous insects
and diseases [23]. Damage can be serious, particularly during drought
years.

Mechanical treatment: Hickories (Carya spp.) commonly produce epicormic
branches or water sprouts after pruning [12].

Wildlife considerations: In New England, black bears are most likely to
damage crops in poor mast (acorn and hickory nut) years [18].

Silviculture: Shagbark hickory is long-lived and slow-growing.
Consequently, it does not respond well to even-aged management systems
if rotations are less than 100 years. It does respond well to release
and is reportedly favored by management for long rotations (200 years or
more) [23].

Following timber harvest, most hickory stems develop from advance
regeneration. Some advance regeneration may be damaged during logging
operations, but plants typically sprout and many quickly overtop older
residual stems [49]. New sprouts are characterized by a straight bole
and rapid growth and are considered the most desirable hickory
regeneration in new stands. Derivation of hickory regeneration
following various types of timber harvest was documented as follows in
an Indiana oak-hickory stand [49]:

clearcut shelterwood med. partial
(percent of total reproduction)

new seedlings 2 2 2
adv. regeneration 30 77 73
new sprouts 56 21 24
stump sprouts 12 0 1

Browse: The nutrient content of shagbark hickory browse varies
seasonally. Loomis [39] reported an average fall ash content of 8.1
percent and a spring ash content of 9.6 percent.

Nuts: Shagbark hickory nuts are high in protein, fats, and
carbohydrates [58]. Caloric content is as follows [52]:

plant cal./g dry wt. cal./nut

kernel 6,570 6,700
shell 4,240 8,600
husk 4,150 16,100

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

More info for the term: tree

Shagbark hickory nuts are sweet and edible [54]. They were once a
staple food of some Native American peoples [34] and today are the
important hickory nut of commerce [57]. Shagbark hickory was first
cultivated in 1911 [7], and many cultivars are now available [57]. At
least one ornamental cultivar has been developed, but it has not been
widely planted. Shagbark hickory is an important shade tree in some
residential areas and is well suited for planting as a specimen tree in
landscaping [23].

Shagbark nuts are highly palatable to many birds and mammals. Hickory
nuts are rated as having fair value for upland game birds and songbirds
and good value for fur and game mammals [13]. Hickory browse appears to
be low of low palatability to most big game species and to all classes
of domestic livestock [23].

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More info for the terms: fruit, seed, vines

Shagbark hickory flowers in late March at the southwestern edge of its
range and as late as early June in the North and Northeast [23].
Flowers open when the leaves are nearly full grown [23]. Fruit ripens
in September and October and splits into four pieces [34]. Seed is
dispersed from September thrugh December. Generalized flowering and
fruiting dates by geographic location are:

Location Flowering Fruiting Authority

New England May 29-June 28 ---- Seymour 1985
n-c Plains April-May Sept.-Oct. Stephens 1973
Great Plains April-May ---- Great Plains
Flora Assoc. 1986
se U.S. May ---- Duncan & Duncan 1988
sw U.S. March-June Sept.-Cot. Vines 1960
NC, SC May October Radford & others 1968

More info for the terms: density, root collar, root crown

Mature hickories often sprout from the root crown when top-killed by
fire [38]; top-killed seedlings sometimes sprout from dormant buds
located on the root collar or lower portions of the stem [49]. Some
seedling establishment may also occur.

Postfire increases in stem density have been reported, but recovery is
often relatively slow. Fifty-five years after a late summer fire in
Connecticut, hickories exhibited greater "relative and absolute levels"
than on adjacent unburned sites [60].

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

More info for the terms: caudex, root crown, seed

survivor species; on-site surviving root crown or caudex
off-site colonizer; seed carried by animals or water; postfire yr 1&2

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

Shagbark hickory regenrates through seed and by vegettaive means.

Seed: Shagbark hickory begins producing seed at approximately 40 years
of age. Optimum seed production occurs between 60 and 200 years of age;
maximum age of seed production is approximately 300 years [57]. Good
crops occur at 1- to 3-year intervals, with little or no seed production
in intervening years [23]. During favorable years, some trees can
produce 1.5 to 2 bushels (53-70 L) of nuts [7]. Tree (stem) diameter
and crown size apparently serve as the best indicators of seed
production [23]. Seed is dispersed by gravity and by birds and mammals
[23,61]. Squirrels and chipmunks are typically much more important as
dispersal agents than birds are. The now-extinct passenger pigeon
dispersed seeds of many species of hickory [61]. During poor seed
years, seed predation by birds, mammals, and insects can eliminate most
of the seed crop [23].

Hickory seeds exhibit embryo dormancy that can be broken by
stratification at 37 degrees F (3 deg C) for 90 to 120 days [23].
Germination of fresh seed ranges from 50 to 75 percent.

Vegetative regeneration: Shagbark hickory typically sprouts
prolifically after plants are cut or damaged by fire [23]. Trees with
diameters up to 8 to 10 inches (20-24 cm) typically sprout from the
stump. As diameter increases stump-sprouting declines, but
"root-suckering" increases. Young sprouts generally compete well in
newly regenerated stands, but after 10 to 20 years, the rate of sprout
growth declines and shagbark hickory may be outcompeted by faster
growing associates [23].

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More info for the terms: climax, forest

Shagbark hickory is slow growing and intermediate in shade tolerance.
Saplings can persist for many years beneath a forest canopy and respond
rapidly when released. It grows as a climax species in most oak-hickory
forests [23]. It is a prominenent late seral or climax species in
old-growth oak stands in Indiana where it replaces early to mid seral
species such as honey locust (Gleditsia triacanthos), black walnut
(Juglans nigra), and oak [45]. It replaces bur oak, black cherry
(Prunus serotina), and white oak in bur oak-chinkapin oak-black oak
forests of Wisconsin and northeastern Kansas [1,16]. It may ultimately
be replaced by more shade-toleant species such as sugar maple, American
basswood, and hophornbeam [1,16].

At the western edge of its range, shagbark hickory has invaded the
prairie [32], but heavy-seeded species such as shagbark hickory are
generally slow to invade new areas [22]. Shagbark hickory has invaded
oldfield communities, but seedlings are rarely observed more than 100
feet (30 m) from the forest margin [11]. In parts of east-central
Indiana and elsewhere, it often establishes in gaps created by dead elms
(Ulmus spp.) [44].

Hicoria ovata (P. Mill.) Britt.

The currently accepted scientific name of shagbark hickory is Carya
ovata (P. Mill.) K. Koch [30]. It is a member of the walnut family,
Juglandaceae [23]. Two varieties are commonly recognized [30]:

Carya ovata var. ovata (Miller) K. Koch
Carya ovata var. australis (Ashe) Little

At least five other varieties, including C. o. var. fraxinifilia Sarg.,
C. o. var. nuttallii Sarg., and C. o. var. pubescens, were formerly
recognized by many authorities [23,50,57]. However, although
occasionally encountered in the literature, they are no longer
recognized by most taxonomists.

Shagbark hickory hybridizes naturally with butternut hickory (C.
cordiformis), pecan (C. illinoensis), and shellbark hickory (C.
laciniosa) [24,36]. Common hybrid products and their derivatives follow
[57]:

Dunbar hickory C. X dunbarii (C. laciniosa x C. ovata)
Laney hickory C. X laneyi Sarg. (C. cordiformis x C. ovata)

Horticultural hybrids between shagbark hickory and butternut hickory,
pecan, shellbark hickory, and mockernut hickory (C. tomentosa) have
also been reported [57].

More info for the term: seed

Shagbark hickory may have potential for use on many types of disturbed
sites. It naturally recolonizes strip mines in Maryland and West
Virginia [25], and lead pit mines with high levels of lead and zinc in
the soil [6]. Strains obtained from floodplain habitats are
particularly well adapted to streambank plantings [14].

Shagbark hickory can be readily propagated from seed. Cleaned seed
averages 100 per pound (221/kg) [57]. Seed may be planted during the
fall, or stratified and planted in the spring [7]. Mulching generally
improves the results of fall plantings.

The wood of shagbark hickory is tough, heavy, hard, and resilient
[23,54]. It is well suited to uses which require a wood capable of
resisting impact and stress [23]. The close-grained heartwood is
reddish brown and the sapwood nearly white [29,57]. Wood was formerly
used to make wheels and spokes for wagons, carriages, carts, and early
automobiles [29]. Shagbark hickory wood is currently used to make
furniture, flooring, tool handles, dowels, ladders, and sporting goods
[29,43].

Shagbark hickory is an excellent fuelwood. It has high heat value and
burns evenly with a long-lasting steady heat. The wood imparts a
hickory-smoked flavor to foods and is often used to make charcoal [23].