Shortleaf Pine

This tree is very fast growing and is highly valued as a source of timber and wood pulp. It is also a promising species for afforestation.

Although Pinus echinata is highly valued for timber and pulpwood, it is afflicted by root rot. It hybridizes with P . taeda , the pine most commonly associated with it.

Trees to 40 m tall; trunk to 1.2 m d.b.h. in native range, usually with adventitious sprouts; bark red-brown, plates scaly with evident resin pockets; crown rounded-conical; 2nd-year branchlets greenish brown or red-brown, aging red-brown or gray, slender, to 5 mm in diam., roughened and cracking below leafy portion; winter buds red-brown, ovoid or cylindric, resinous. Needles 2 (or 3) per bundle, gray- or yellow-green, straight, slightly twisted, (5-)7-11(-13) cm × ca. 1 mm, stomatal lines present on all surfaces, base with persistent sheath 0.5-1(-1.5) cm. Seed cones solitary or clustered, subsessile or shortly pedunculate (peduncle to 1 cm), red-brown, aging gray, ovoid-conical when open, 4-7 cm, maturing in 2 years. Seed scales lacking contrasting dark border adaxially distally; umbo with an elongated or stout and short, sharp prickle. Seeds gray or nearly black, ellipsoid, ca. 6 mm; wing 1.2-1.6 cm.

Trees to 40m; trunk to 1.2m diam., straight; crown rounded to conic. Bark red-brown, scaly-plated, plates with evident resin pockets. Branches spreading-ascending; 2-year-old branchlets slender (ca. 5mm or less), greenish brown to red-brown, often glaucous, aging red-brown to gray, roughened and cracking below leafy portion. Buds ovoid to cylindric, red-brown, 0.5--0.7(--1)cm, resinous. Leaves 2(--3) per fascicle, spreading-ascending, persistent 3--5 years, (5--)7--11(--13)cm ´ ca. 1mm, straight, slightly twisted, gray- to yellow-green, all surfaces with fine stomatal lines, margins finely serrulate, apex abruptly acute; sheath 0.5--1(--1.5)cm, base persistent. Pollen cones cylindric, 15--20mm, yellow- to pale purple-green. Seed cones maturing in 2 years, semipersistent, solitary or clustered, spreading, symmetric, lanceoloid or narrowly ovoid before opening, ovoid-conic when open, 4--6(--7)cm, red-brown, aging gray, nearly sessile or on stalks to 1cm, scales lacking contrasting dark border on adaxial surfaces distally; umbo central, with elongate to short, stout, sharp prickle. Seeds ellipsoid; body ca. 6mm, gray to nearly black; wing 12--16mm. 2 n =24.

Cultivated. Fujian (Minhou Xian), Jiangsu (Nanjing Shi), Zhejiang (Fuyang Xian) [native to SE United States]

Uplands, dry forests; 200--610m; Ala., Ark., Del., Fla., Ga., Ill., Ky., La., Md., Miss., Mo., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Va., W.Va.

shortleaf pine
shortleaf yellow pine
southern yellow pine
yellow pine
shortstraw pine
Arkansas soft pine
old field pine

The federally endangered red-cockaded woodpecker lives in old-growth
shortleaf pine with decayed heartwood [10].

Shortleaf pine is a medium-sized, native, evergreen conifer with
relatively short needles and thin, flaky, black bark that becomes
reddish brown with age [43]. Shortleaf pine attains a height of 100
feet (30 m) and a d.b.h. of 24 to 36 inches (61-91 cm). Individuals
generally grow straight and have conical crowns. Shortleaf pine is
capable of growing a deep taproot and is resistant to windthrow [24].

Shortleaf pine has the widest geographic range of any pine in the
southeastern United States [24]. It grows in the Atlantic Coast States
from southeastern New York to northern Florida; throughout the Gulf
States; and inland to western Pennsylvania, southern Ohio, southern
Illinois, southern Missouri, eastern Oklahoma, and eastern Texas
[24,25]. Arkansas contains more shortleaf pine than any other state
[37].

More info for the terms: competition, crown fire, fire regime, tree

Shortleaf pine is classified as fire-resistant [4]. It is more tolerant
than loblolly pine [45] and less tolerant than pitch pine [16]. It has
a low susceptibility to crown fire because of its moderately high and
open crown and moderately open stand structure. It is able to endure
some fire defoliation [4] but is not able to survive frequent or severe
fires [28]. Shortleaf pine has medium-thick bark which protects the
tree and the dormant buds within the bole and at the base. Shortleaf
pines up to about 30 years of age will sprout from dormant basal buds if
the crown is top-killed [28,31]. Shortleaf pine regenerates well after
fire since exposed mineral soil and lack of competition facilitate
seedling establishment.

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 terms: forest, hardwood, headfire, litter

Fire is important to shortleaf pine management. Fire effectively
prepares the necessary seedbed for shortleaf pine regeneration and can
be used to control competing hardwoods [42]. Fire may not be
beneficial, however, in areas where competing hardwoods sprout
vigorously after fire. A controlled fire on the Cumberland Plateau in
Kentucky resulted in a greater number of hardwood stems and made
regeneration of shortleaf pine almost impossible [44]. Ferguson [13]
concluded that an ideal fire in which hardwoods are killed and pines are
not killed may be unattainable.

In some areas, fire has been effective in controlling hardwoods. In the
Ouachita Mountains of Arkansas, 3 consecutive years of summer fires
reduced the number of 5.5 inch (14 cm) d.b.h. and smaller hardwood stems
[46]. In upland New Jersey and in the Piedmont, light fires at 5-year
intervals are recommended as soon as the young pines are able to
withstand fire [9,27]. In the Piedmont, however, understory vegetation
and litter are often too moist to carry fire [9]. In eastern Texas, a
headfire during the growing season with a followup fire to control the
hardwood sprouts resulted in at least temporary control of hardwood
stems less than 1.5 inches (4 cm) d.b.h. and negligible mortality of
greater than 4 inch (10 cm) d.b.h. shortleaf pines [13].

If fire occurs 5 years after establishment, shortleaf pine will have an
edge over loblolly pine because of shortleaf pine's ability to sprout.
Loblolly will overtake shortleaf, however, if fire intervals are 10
years or more [45]. Shortleaf pine sprouts that start from seedlings or
saplings have good form and can produce commercial timber [28]. In a
mixed hardwood-pine forest, fire more frequent than every 10 years can
eliminate or decrease shortleaf pine [14].

Fire-damaged trees are more susceptible to insect infestation [24].
Southern pine beetle attack on shortleaf pine is aided or induced by
fire [4]. Fire should not be prescribed in shortleaf pine stands that
are habitat for the federally endangered red-cockaded woodpecker if
southern pine beetles are present. A stand infected with littleleaf
disease should not be burned because fire will destroy the organic
material necessary for soil build-up [42].

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More info for the term: phanerophyte

Phanerophyte (mesophanerophyte)

More info for the terms: cover, herbaceous, shrubs, vines

Shortleaf pine is common in the Atlantic and Gulf coastal plains, the
upper and lower Piedmont, and on floodplains. It ranges in elevation
from 10 to 3,000 feet (3-910 m), and usually grows on south- or
west-facing slopes. Shortleaf pine commonly grows on old agricultural
fields [24,42].

Shortleaf pine has great adaptability, but grows best on moist,
well-drained, deep, sandy or silty loam. Soils are typically Ultisols.
Shortleaf pine does not grow well in soils with high pH, high calcium
content, excessive internal drainage, or high organic content [24].
While shortleaf pine generally occurs with loblolly pine, shortleaf pine
prevails on the drier, coarser, less acidic, and infertile sites [5,45].

Common overstory associates include scarlet oak (Quercus coccinea),
southern red oak (Q. falcata), water oak (Q. nigra), willow oak (Q.
Phellos), blackgum (Nyssa sylvatica), sweetgum (Liquidambar
styraciflua), Table Mountain pine (Pinus pungens), mockernut and pignut
hickories (Carya tomentosa and C. glabra), winged elm (Ulmus alata),
sourwood (Oxydendrum arboreum), red maple (Acer rubrum), American beech
(Fagus grandifolia), and Carolina ash (Fraxinus caroliniana) [24,40].
(Also see SAF cover types).

Common understory woody species include mountain laurel (Kalmia
latifolia), flowering dogwood (Cornus florida), redbud (Cercis
canadensis), and persimmon (Diospyros virginiana). Because of shortleaf
pine's wide distribution, associated understory shrubs, vines, and
herbaceous species are numerous [24].

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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 term: hardwood

21 Eastern white pine
40 Post oak - blackjack oak
43 Bear oak
44 Chestnut oak
45 Pitch pine
46 Eastern redcedar
51 White pine - chestnut oak
52 White oak - black oak - northern red oak
57 Yellow-poplar
70 Longleaf pine
75 Shortleaf pine
76 Shortleaf pine - oak
78 Virginia pine - oak
79 Virginia pine
80 Loblolly pine - shortleaf pine
81 Loblolly pine
82 Loblolly pine - hardwood
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):

FRES10 White - red - jack pine
FRES12 Longleaf - slash pine
FRES13 Loblolly - shortleaf pine
FRES14 Oak - pine
FRES15 Oak - hickory

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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

K100 Oak - hickory forest
K104 Appalachian oak forest
K110 Northeastern oak - pine forest
K111 Oak - hickory - pine forest
K112 Southern mixed forest

More info for the term: duff

Mature shortleaf pine is killed by high-severity crown fires, but
withstands low- to moderate-severity surface fires [9,23]. Shortleaf
pine is most susceptible to fire in the first 6 to 10 years after
establishment [1]. Seedlings up to 5 feet (1.5 m) tall are usually
top-killed, and saplings often suffer bark char, needle scorch, or
needle consumption [23]. Seeds in the duff will be killed by fire [42].

Shortleaf pine mortality from fire is dependent on the degree of crown
scorch, basal damage, and season of fire. After a summer fire, there
was 60 percent mortality of shortleaf pines of any size that had
complete crown scorch combined with extensive basal damage. After a
winter fire, less than 50 percent died from similar injuries. If basal
damage was not extensive but crown scorch complete, there was 30 percent
mortality from the summer fire [12]. Trees greater than 5 feet (1.5 m)
tall seldom die if less than 70 percent of the crown is scorched [42].

Because of thick bark, basal injury is not common. In areas with
frequent fire, only 11 percent of shortleaf pine showed basal injury
[14].

More info for the term: cover

Shortleaf pine seeds are an important food source for birds and small
mammals [24]. Deer browse on seedlings. Stands of seedlings and
saplings provide cover for bobwhite quail and wild turkey [24,42].
Old-growth shortleaf pine provides habitat for cavity dwellers [10].

More info for the term: forest

Shortleaf pine is dominant in several seral communities. The
published classifications listing shortleaf pine as a dominant species
in community types (cts) are presented below:

Area Classification Authority

se US gen. forest cts Waggoner 1975

se US gen. forest cts Sheffield and
others 1989

More info for the term: tree

Tree

More info for the terms: basal area, codominant, competition, hardwood, herbaceous, litter, natural, presence, seed, seed tree, tree

Shortleaf pine is usually managed in even-aged stands with clearcutting
followed by artificial regeneration. Natural regeneration can be used,
but seedbed preparation is recommended. Seed tree silviculture requires
11 square feet basal area per acre (2.5 m sq/ha) of shortleaf pine seed
trees. A shelterwood system requires 20 to 30 square feet of basal area
per acre (4.6-6.9 m sq/ha) of shortleaf pine [1]. Seedbed preparation
should be done early to benefit from the high viability of early
released seeds [42].

Uneven-aged management requires frequent harvest of single trees and
seedling establishment once every 10 years [1,24]. Shortleaf pine
seedlings will establish if overstory is reduced to 45 to 60 square feet
basal area per acre (10.3-13.8 m sq/ha) [1].

Control of competing understory is generally considered necessary for
maintenance of shortleaf pine stands [17,37]. Hardwoods suppress
shade-intolerant seedlings and saplings, and a thick litter discourages
seedling establishment. However, hardwoods also prevent soil moisture
loss and discourage competing herbaceous vegetation. Cain [8] suggests
that the coexistence of hardwoods with shortleaf pine may be an
antagonistic symbiosis. Yocum and Lawson [47] found that intensive
hardwood control on southern exposures actually decreased the rate of
establishment of shortleaf pine seedlings.

Control of dense understory can increase the growth rate of shortleaf
pine [17,29]. Lloyd and others [29] reported a 17 percent increase in
2-year shortleaf pine diameter growth after a spring felling of
competing hardwoods and a 22 percent increase in diameter growth after a
winter felling followed by an herbicide treatment. Cain [7] reported
that control of herbaceous vegetation resulted in increases in pine
growth, while control of hardwoods had little effect. After 5 years,
pines on herbaceous control plots averaged more than 4 feet taller than
pines on untreated plots or woody control plots. However, even on the
untreated plots, pines exceeded the herbaceous and woody competitors by
6 feet. Cain [7] concluded that control of hardwood competition is not
necessary if pines, hardwoods, and herbaceous species establish on a
site at the same time. The relatively fast-growing shortleaf pine
seedlings dominate over hardwoods in 5 to 7 years [8].

Loblolly pine outperforms shortleaf pine in loblolly's natural range
because it grows faster as a juvenile. If planted together, however,
shortleaf pine can survive and attain a codominant crown position in
mature even-aged stands [6].

Littleleaf disease, the most serious disease afflicting shortleaf pine,
affects 30 to 50 year-old trees and causes needles to turn yellow and
fall off. Littleleaf disease is a recent phenomenon and occurs only
where shortleaf pine has colonized severely eroded agricultural land.
The disease is caused by a combination of factors: low soil nutrients,
poor internal drainage, and the presence of Phytophthora cinnamomi, a
soil fungus. The poor drainage allows the fungus, which attacks the
feeder roots, to sporulate abundantly. Hardwoods should not be
controlled where littleleaf disease is present because the soil needs to
build up. Afflicted trees respond positively to large doses of nitrogen
[33,42]. Mueller-Dombois and others [33] claim it is not a disease, but
a dieback or decline phenomenon.

Other common diseases are root rot and red heart rot. Seedlings are
subject to damping off [24].

Nantucket pine tip moth (Rhyacionia frustrana) larvae bore into the
shortleaf pine buds of young trees and kill the tips. Southern pine
beetle (Dendroctonus frontalis) attacks the bark of shortleaf pine and
individuals usually die in less than 1 year [24,42]. Redheaded pine
sawfly (Neodiprion lecontei), loblolly pine sawfly (N. taedae linearis),
pine engraver beetle (Ips spp.), and black turpentine beetle
(Dendroctonus terebrans) attack and damage shortleaf pine.

The decline of old growth shortleaf pines has resulted in a decline in
population of the federally endangered red-cockaded woodpecker. Death
of old growth shortleaf pine is primarily from southern pine beetle. In
order to minimize cavity tree mortality, site disturbances should be
limited when southern pine beetle populations are elevated [10].

Acid rain is suspected of causing an abnormal decrease in growth of
shortleaf pine in the past 25 years [19]. Ozone concentrations two and
a half times the ambient ozone concentration cause decreased growth in
shortleaf pine [36].

AL AR DE FL GA HI IL KY LA MD
MS MO NJ NY NC OH OK PA SC TN
TX VA WV

Shortleaf pine is used as an ornamental [24].

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More info for the term: seed

Shortleaf pine flowers in late March in the South and in late April in
the North. Cones mature in the late summer or early fall of the second
growing season [21,24]. Seed dispersal begins in late October or early
November, and generally coincides with a cold front bringing low
temperatures, low humidity, and high winds [42]. Seventy percent of the
seeds fall in 1 month and 90 percent within 2 months [24].

More info for the terms: competition, hardwood, herbaceous, prescribed fire, root collar, tree

Sprouting: Seedlings and saplings top-killed by fire will sprout from
dormant buds at the root collar. Sprouting is not as consistent in
trees larger than 8 feet (2.4 m) tall [14]. There are usually 4 to 8
new sprouts per tree, but as many as 70 sprouts where fires are frequent
[42]. The sprouts grow 1 to 2 feet (30-61 cm) in the first year.
Multiple sprouts act as a firebreak for the central leader. When the
leaders are 3 to 4 feet (1-1.2 m) tall they can survive defoliation by
fire as long as the terminal leaders are not charred. Many of the
sprouts die back when the leader is no longer affected by fire [20].

A well-developed basal stem crook protects dormant buds in seedlings.
In a study in which 100 shade-grown 1-year-old shortleaf pine seedlings
were subject to a prescribed fire, 33 percent with no basal crook
sprouted, 39 percent with a slight basal crook sprouted, 81 percent with
a well-developed basal crook sprouted, and 93 percent with a very
well-developed basal crook sprouted [28]. Garren [14] found 56 percent
of shortleaf seedlings survive by sprouting.

Growth: Crown scorch usually results in growth losses in young trees.
Diameter growth rate of shortleaf pine decreased as much as 75 percent
after one fire [14]. In older trees, there is no growth loss if there
is little or no needle scorch [23]. Trees 4 to 10 inches (10-25 cm)
d.b.h. continue to grow at normal rates after severe groundfire, even
if the crowns are scorched [20]. Yocum [46] found light to moderate
summer fires had no effect on the growth of 60-year-old shortleaf pines
in Arkansas. If trees are not damaged and hardwood and herbaceous
competition is eliminated, pine growth will inrcease.

Reproduction: Seeds released from on- and off-site sources will
germinate in the soil exposed by fire.

More info for the terms: root crown, seed

crown-stored residual colonizer; short-viability seed in on-site cones
off-site colonizer; seed carried by wind; postfire years one and two
survivor species; on-site surviving root crown or caudex

More info for the terms: competition, cone, cotyledon, epigeal, monoecious, root crown, seed, tree

Seed production and dissemination: Shortleaf pine is monoecious. It
begins producing seeds at 20 years of age. The cone yields 25 to 38
seeds. A good cone crop, 80,000 seeds per acre (200,000/ha), occurs
every 3 to 10 years in the North and every 3 to 6 years in the South.
Seeds are equipped with wings and are dispersed as far as 200 to 300
feet (61-91 m), although most fall close to the source tree [1,24].

Seedling development: Seeds on the ground are naturally stratified
during the winter and epigeal germination takes place in the early
spring [24]. The viability of seeds decreases as the period of seed
fall progresses [42]. Exposed mineral soil aids seedling establishment
[20,24]. The seedling stem grows slowly the first 2 years while the
root system develops. One to three-year-old open-grown seedlings and 3
to 9-year-old shade-grown seedlings fall over and remain semiprostrate
for 1 to 2 years before resuming erect positions. A permanent crook
develops at the cotyledon. The crook, at ground level, is later
obscured by the thickening stem after a tree reaches 8 to 10 feet
(2.4-3.0 m) in height [28,32,42]. If suppressed by competition,
seedlings will have poorly developed crooks [28].

Vegetative reproduction: If the crown is damaged or killed, shortleaf
pine up to 6-8 inches (15-20 cm) in d.b.h. sprouts vigorously from
dormant axillary buds at the root crown and dormant buds at nodes in the
bole [24,28,32,42].

Rooting habits: Shortleaf pine grows a large, massive taproot in deep
soil with adequate drainage, but often does not in shallow soil where
the subsoil is hard or clayey [18,24,42]. Roots have a low tolerance
for poor soil aeration and high water table conditions [24,32]. Lateral
roots grow near the surface with 56 to 64 percent of the roots in the
top 6 inches (15 cm) of soil and 17 to 25 percent from 6 to 12 inches
(15-30 cm) [2]. Seedlings grown in place are more likely to have a
downward-oriented root system than planted seedlings [18].

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More info for the terms: competition, fire frequency, frequency, hardwood, relict

Shortleaf pine is shade intolerant and is suppressed by hardwood
competition. It commonly grows in even-aged stands [24]. Shortleaf
pine, a pioneer species, invades old agricultural fields. Many
shortleaf pine stands became established after the Civil War when fields
were abandoned [40]. Shortleaf pine invasion of oldfields begins within
5 years of abandonment, and a closed-canopy stand is formed after 10 to
15 years. A 40-year-old shortleaf pine stand may have a considerable
hardwood understory. In the absence of fire, hardwoods attain dominance
[2,3,5,14,42]. After 150 to 200 years, only a few relict pines may
remain [3].

In the New Jersey Pine Barrens, where fire frequency is less than 10
years, pitch pine and scrub oaks (Quercus spp.) supplant shortleaf pine
[26]. In Alabama, shortleaf pine will succeed longleaf pine (Pinus
palustris) in the absence of fire [41].

The currently accepted scientific name of shortleaf pine is Pinus
echinata Mill. [24]. There are no recognized varieties or subspecies.
Shortleaf pine hybridizes with loblolly pine (P. taeda), pitch pine (P.
rigida), pond pine (P. serotina), and spruce pine (P. glabra) [24,25].

Because of its adaptability, shortleaf pine has potential for
rehabilitating eroded areas and mine sites [24]. For best success, mine
sites should have a pH between 4.5 and 6.5 and be below 2,500 feet (762
m). Shortleaf pine does best on mine sites when planted as a pure stand
or mixed with other pines. It also grows well with European alder
(Alnus glutinosa) [39].

More info for the term: softwood

Shortleaf pine, an important commercial species, ranks second to
loblolly pine in total softwood volume harvested in the southeastern
United States [6,37]. After 36 years, an even-aged stand yields 5,000
to 6,000 total merchantable cubic feet per acre (350-415 cubic m/ha)
[1]. The strong wood is used for lumber, plywood, structural material,
and pulpwood [24].

Shortleaf pine is now considered a major component of three forest cover types (Society of American Foresters, 16), Shortleaf Pine (Type 75), Shortleaf Pine-Oak (Type 76), and Loblolly Pine-Shortleaf Pine (Type 80). Although shortleaf pine grows very well on good sites, it is generally only temporary and gives way to more competitive species, particularly hardwoods. It is more competitive on drier sites with thin, rocky, and nutrient deficient soils. With the species' ability to grow on the medium and poor sites, it is not surprising that shortleaf pine is a minor component of at least 15 other forest cover types.

21 Eastern White Pine
40 Post Oak-Blackjack Oak
43 Bear Oak
44 Chestnut Oak
45 Pitch Pine
46 Eastern Redcedar
51 White Pine-Chestnut Oak
52 White Oak-Black Oak-Northern Red Oak
57 Yellow-Popular
70 Longleaf Pine
78 Virginia Pine-Oak
79 Virginia Pine
81 Loblolly Pine
82 Loblolly Pine--Hardwood
110 Black Oak

In addition to species in the cover types, other common associates include scarlet oak (Quercus coccinea), southern red oak (Q. falcata), blackgum (Nyssa sylvatica), sweetgum (Liquidambar styraciflua), Table Mountain pine (Pinus pungens), mockernut and pignut hickories (Carya tomentosa and C. glabra), winged elm (Ulmus alata), sourwood (Oxydendrum arboreum), red maple (Acer rubrum), water oak (Quercus nigra), willow oak (Q. phellos), American beech (Fagus grandifolia), and Carolina ash (Fraxinus caroliniana). Common understory woody plants include mountainlaurel (Kalmia latifolia), flowering dogwood (Cornus florida), redbud (Cercis canadensis), persimmon (Diospyros virginiana), and eastern redcedar (Juniperus virginiana).

Among the more common understory shrubs vines, and herbaceous vegetation are blueberries (Vaccinium spp.), huckleberries (Gaylussacia spp.), deerberry (Vaccinium stamineum), Japanese honeysuckle (Lonicera japonica), greenbriers (Smilax spp.), Virginia creeper (Parthenocissus quinquefolia), poison ivy (Toxicodendron radicans), grape (Vitis spp.), asters (Aster spp., tick-trefoil (Desmodium spp.), tickseed (Coreopsis spp.), bushclover (Lespedeza spp.), St. Andrews cross (Ascyrum hypericoides var. multicaule), birdfoot violet (Viola pedata), sensitive brier (Schrankia spp.), early azalea (Rhododendron roseum), pussytoes (Antennaria spp.), butterfly-pea (Clitoria mariana), senna (Cassia spp.), bugbanes (Cimicifuga spp.), longleaf uniola (Uniola longifolia), panicums (Panicum spp.), sedges (Carex spp.), and bluestems (Andropogon spp.).

Shortleaf pine grows in a fairly humid region but is the least exacting of the southern pines as to temperature and moisture (18). Annual precipitation averages between 1020 mm (40 in) on the western edge of its range and 1520 mm (60 in) at the southern tip of its range (59). Snowfall averages less than 41 cm (16 in) over most of the shortleaf pine range but may be twice that amount in some of the higher elevations of the Appalachians northward into Pennsylvania. The region of best development for the species is in Arkansas, northern Louisiana, and the southern Piedmont, where precipitation ranges from 1140 to 1400 mm (45 to 55 in) and averages 1270 mm (50 in). The 10° C (50° F) average annual temperature isoline closely parallels the northern limit of shortleaf pine. Over its range, average annual temperatures vary from 9° C (48° F) in New Jersey to 21° C (70° F) in southeast Texas.

Littleleaf disease is the most serious pathological threat to shortleaf pine, occurring on poorly drained soils from Virginia to Mississippi and south to the Gulf Coast (61). The disease results from combination of certain factors, including root destruction by Phytophthora cinnamomi, periodic excessive soil moisture deficits, poor aeration, low fertility, damage from nematodes, and perhaps toxic levels of manganese. These forces combine to impede mineral absorption, particularly nitrogen (18,27). Symptoms of the disease usually appear when the stands are 30 to 50 years old, but seldom in stands less than 20 years old. Growth rates of infected trees may be greatly reduced, and mortality may be very high. Fertilization with nitrogen at 224 kg(ha (200 lb/acre) can relieve some of the symptoms in its early stages. No practical control measures for littleleaf disease in forest stands have been developed. It is suggested that proper site selection, species selection, and maintenance of stand vigor are the best defenses against this disease (18,52).

Shortleaf saplings and older trees are moderately susceptible to attack by Heterobasidion annosum, a root rot. Losses in thinned plantations and occasionally in natural stands have occurred, but they have not been in general. Red heart, caused by Phellinus pini, may occur in older trees but is rare in stands under 80 years old. Several other relatively unimportant diseases occur in shortleaf pine (27).

Shortleaf pine seedlings are subject to damping off and root rot caused by several fungi, usually when soils have a pH above 6 and weather conditions are wet. Foliage of shortleaf pine normally does not develop serious diseases, but at least eight needle rusts are known to attack the species (27). Brown spot from Scirrhia acicola may be aggressive. The rust, Cronartium comandrae, has occasionally damaged shortleaf seedlings.

Young shortleaf pines are attacked by Nantucket pine tip moth (Rhyacionia frustrana). This insect has become a major pest in the eastern United States and may have greater impacts on growth than previously believed. Chemical control of this pest is difficult in forest situations, although early results of spray applications have shown promise. The redheaded pine sawfly (Neodiprion lecontei) is our most destructive sawfly, and shortleaf is one of its preferred species. Loblolly pine sawfly (N. taedae linearis), attacks shortleaf pine in at least eight States. Reproduction weevils are the most serious insect pests of pine seedlings, reportedly killing 20 to 30 percent of seedlings planted in cutover pine lands. Pales weevil (Hylobius pales), and pitch-eating weevil, (Pachylobius picivorus), are most destructive species over the eastern and southern United States (1,17).

The southern pine beetle (Dendroctonus frontalis), occasionally causes great losses. Other important insects are the pine engraver beetles (Ips spp.), especially during severe droughts, and the black turpentine beetle (Dendroctonus terebrans).

Shortleaf pine is generally fire resistant, but wildfires in young plantations are very damaging. The crowns are usually killed, but shortleaf pine will sprout from the base and form new stems. Larger trees may be killed by very hot fires, particularly if fuels near the tree bases are heavy. Fire damaged trees are also more susceptible to insect damage (1).

Shortleaf pine is generally considered to be windfirm over most of its range, although trees may be uprooted by wind where root systems are shallow (18). Shortleaf pines may also be damaged by severe ice storms. A single ice storm resulted in loss of almost one-third of the volume in a very heavily stocked shortleaf pine stand in north Arkansas (37). Thinned, pole-size stands are especially susceptible to damage, which often includes main stem breakage.

Acid rain may reduce growth of shortleaf pine (28). It may also result in aluminum toxicity to the roots of young trees, but could improve growth through increased availability of mineral nutrients (49). Extreme drought can result in or contribute to mortality of shortleaf pine (70).

Shortleaf pine is monoecious (29). Male and female strobili emerge from late March in the southwestern part of its range to late April in the northeastern sections. Open-grown trees may produce strobili 2 weeks earlier (18). Male strobili are more common on the basal part of new shoots, mostly on older lateral branches in the lower crown. The male strobili are arranged in indistinct spirals in clusters 1.3 to 5.1 cm (0.5 to 2.0 in) long. They may be green or yellow to reddish purple before ripening but become brown to light brown at the time of pollen shed. Female strobili

emerge from the winter bud soon after the male strobili and are green or red to purple. They are nearly erect at the time of pollination, and 1.0 to 3.8 cm (0.4 to 1.5 in) long. After pollination, scales of the female strobili close and slow development begins. By the end of the first growing season they are about one-eighth to one-fifth the length of mature cones. Cones develop rapidly after fertilization takes place in early spring or summer of the second growing season. They mature by late summer or early fall and are green to light or dull brown when ripe (29).

Shortleaf pine generally does not bear seeds until about 20 years of age, but both male and female flowers have been reported on 5-year-old trees. Viable seeds have been produced on 9-year-old trees, although this is exceptional. Trees usually produce seeds abundantly when they reach a diameter of about 30 cm (12 in) (18).

Because of shortleaf pine's wide distribution and the range in elevation at which it grows, considerable racial variation has developed. The Southwide Pine Seed Source Study indicated important racial differences in height, volume growth, survival, and degree of early cone production (63,65). Seed collection and planting zones have been drawn for shortleaf pine on the basis of these results (62,64). The zones are primarily a function of latitude, with much wider movement of seed being acceptable in an east-west direction than north-south. There is some indication that the shortleaf pine population west of the Mississippi River has an inherently faster growth rate than the eastern population (64).

Other studies have revealed differences in height growth, volume growth, wood specific gravity, chemical content, and foliage color (14). Shortleaf pine from some locations grew faster than loblolly pine, but loblolly was generally the faster growing species. In Georgia, South Carolina, and Virginia, shortleaf pine planted on sites where littleleaf disease was likely to occur revealed that trees were healthier from locations west to east, and those from upland locations were healthier than those from coastal plain areas. Specific gravity of shortleaf pine has been shown to increase slightly from the north to the south (19), and monoterpene chemical composition of wood oleoresin as found to vary in a clinal pattern, with a-pinene increasing from east to west while b-pinene decreased (12).

Natural hybridization of shortleaf pine and loblolly pine west of the Mississippi River is considered to be extensive and is probably a cause of many inherent variations in the species (24). Such hybridization would contribute to variation among trees through creation of intermediate types and introgression towards one or both parent species. The natural variations of shortleaf pine have been the basis for selecting trees having superior qualities. These qualities include growth rate, stem and crown form, resistance to littleleaf and other diseases, wood specific gravity, tracheid length, extractives, oleoresin content, and seed production (14). Many of these traits have been the basis for selecting individual trees for seed orchards, which are rapidly becoming the primary source of seeds for planting programs. In 1974, there were 190.6 ha (471 acres) of shortleaf seed orchards in the United States, with 158.2 ha (391 acres) in Federal management (56); more than half of the total acreage is in Arkansas.

Several artificial hybrids have been produced with shortleaf pine. They are of special interest because they offer the opportunity to combine specific qualities of individual species. For example, shortleaf pine can be crossed with slash pine (Pinus elliottii) to yield progeny that are resistant to fusiform rust, a disease to which slash pine is highly susceptible. Shortleaf pine has been successfully crossed with slash, loblolly, longleaf, and Sonderegger pines (P. elliottii, P. taeda, P. palustris, and P. x sondereggeri) (50,55). Some of the hybrids have also been backcrossed. Shortleaf pine x loblolly pine hybrids have also shown resistance to fusiform rust, have grown as well as or better than one or both parents, and have shown increased resistance to cold and ice damage (30). Characteristics of most shortleaf hybrids, as well as other pine hybrids, are intermediate between the parent species. Fusiform rust resistance of shortleaf x slash hybrids, however, is closer to shortleaf pine than slash pine (66). The longleaf x shortleaf pine hybrid is difficult to produce and crosses have yielded only a few seedlings. These have shown intermediate characteristics, but seedling height growth was not delayed as it is characteristically for longleaf pine. Shortleaf x pitch pine (P. echinata x P. rigida) and Table Mountain x shortleaf pine (P. pungens x P. echinata) hybrids have also been produced and generally have intermediate characteristics (14).

Shortleaf pines on good sites attain a height of 30 m (100 ft) or more and diameters (d.b.h.) of 61 to 91 cm (24 to 36 in). Heights of nearly 40 m (130 ft) and d.b.h. of 122 cm (48 in) have been recorded (18), but the practice of growing trees to over 70 years of age is not commonly followed in managed stands because net growth rates decline rapidly. One of the biggest shortleaf pines grows in Mississippi. It measures 105 cm (41.5 in) in d.b.h. and 42 m (138 ft) tall and attests to the large size these trees may attain.

Considering the importance of shortleaf pine, the information available on growth and yield is limited (40). The first variable-density yield information for a variety of sites and ages in natural stands was developed from forest survey data (39,41). The model provides volume and basal area predictions for natural, even-aged, shortleaf pine stands in the West Gulf region. For example, a 60-year-old stand with a basal area of 16.1 m²/ha (70 ft²/acre) and a site index of 21.3 m (70 ft) would have a sawtimber volume of 119.8 m³/ha (1,712 ft³/acre) for trees 23 cm (9 in) d.b.h. and larger (39). For trees 13 cm (5 in) d.b.h. and larger, the volume would be 129.6 m³/ha (1,851 ft³/acre)(41). These yields are for a broad range of stand conditions, including unmanaged stands and those with a significant hardwood component. Managed stands should provide greater yields. Data from uneven-aged shortleaf pine stands in the Interior Highlands of Arkansas were used to construct a similar model (42). After the cyclic harvest levels have stabilized, the periodic annual growth (based on International 1/4-inch rule) for these stands is 5.3 m³/ha (381 fbm/acre), with a residual after cut volume of 89.3 m³/ha (6,378 fbm/acre).

Stand structure and yield data for shortleaf pine plantations in the Tennessee, Alabama, and Georgia Highlands show that with a site index of 18.3 m (60 ft) at base age 25 years, mean annual increment of total volume culminates near age 20 (54), at about 15.8 m³/ha (225 ft³/acre). Total volume yield (outside bark) of all trees at age 40, where the site index is 9.1 m (30 ft) and density is 3,090 stems per hectare (1,250/acre), is about 180 m³/ha (2,570 ft³/acre). For the same age and planting density, the volume where site index is 18.3 m (60 ft) is about 451 m³/ha (6,446 ft³/acre). Basal areas for these two stand conditions are 31 and 39 m²/ha (135 and 171 ft²/acre), respectively. The actual numbers of trees are 1,870 and 875/ha (757 and 354/acre). Thinnings in such stands will likely provide greater volume production through capture of mortality and will increase average diameter (68).

Natural shortleaf pine stands in Missouri showed significantly higher net volume yields when thinned to about 21 m²/ha (90 ft²/acre) or above, at age 51. The presence of hardwoods reduced growth and yield of the stands by 8 to 12 percent (48). In south Arkansas, annual growth of uneven-aged shortleaf-loblolly pine stands averaged 5.9 m³/ha (84 ft³/acre) during a 24-year measurement period (44). Annual sawtimber growth of these stands averaged 6.0 m³/ha (432 fbm/acre).

Shortleaf pine is a shade-intolerant species and does not survive or grow well when suppressed (16). Young shortleaf pines are generally slower growing and slower to dominate a site than loblolly pine or many hardwood competitors, but they usually will endure competition longer than its common associate, loblolly pine. Shortleaf pine can maintain dominance on most sites after it overtops competing vegetation, but in general hardwoods cannot be eliminated from pine sites (7,9,10). On very good sites, however, it may not outgrow competing species such as sweetgum and red maple. Control of both woody and non-woody competition usually results in economic gains (15,35).

In young, well-stocked shortleaf pine stands, trees begin to compete with each other within a few years after establishment, and diameter growth rates decline (69). Even though growth rates decline, shortleaf pine persists in very dense stands. Natural pruning occurs as the canopies close, but it is slower than on loblolly pine (Pinus taeda) or longleaf pine (P. palustris). Shortleaf pine usually responds well to release, even when the trees are mature (18,72). Removal of understory competition may also increase growth rates (5).

Because of its intolerance to shade and other environmental factors, shortleaf pine commonly grows in even-aged stands (22,32). Natural and artificial regeneration methods are used to establish such stands (4). Uneven-aged management is feasible, however, and may be an attractive alternative for small tracts of land (44,45,67).

Shortleaf pine seedlings can develop a taproot at an early age, which may become quite massive if allowed to grow uninhibited (38). If the taproot is damaged, the seedling can grow a new one (34). In much of the region where shortleaf pine grows, however, taproots do not develop because of shallow, rocky soils and in some cases hardpans. Lateral roots tend to grow near the soil surface; they are generally concentrated in the upper 46 cm (18 in) of the soil and rarely occur below a depth of 102 cm (40 in).

Tree growth response tends to be related to root development. The cross-sectional area of roots at groundline and the composite root area or sum of the areas of the first-order lateral roots plus the area of the taproot of 3- to 9-year-old shortleaf pines from Arkansas, Oklahoma, and Texas were found to be highly correlated. This suggests that basal stem diameter growth is directly related to root development (11). Root systems of trees originating from natural or artificial seeding are more likely to have a single taproot than planted trees. Trees with root systems oriented downward have better height growth than trees with surface-oriented root systems (26).

Seedfall usually begins in late October or early November when cones reach a specific gravity of about 0.88 or when they will float in SAE 20 motor oil (60). As the cones dry, the bracts open, allowing the winged seeds to fall out. Most seeds fall fairly close to the tree from which they originate, but in varying patterns. In an Arkansas study, half of the shortleaf pine seeds fell into a forest clearing within 20 m (66 ft) of forest walls 21 m (70 ft) high, and 85 percent fell within 50 m (165 ft) of the forest walls (71). Wall height and orientation and prevailing wind direction had little effect on the dispersal pattern, probably because of topographic features and frontal winds. In other observations, however, where prevailing winds were from one direction during seedfall, seeds were dispersed in a v-shaped pattern with the apex at the base of the tree. Under such conditions, several times as many seeds were caught in traps at a distance of 40 m (132 ft) from the tree on the leeward side as were caught at a distance of 20 m (66 ft) on the windward side (18).

About 70 percent of the seeds fall within a month after maturity and 90 percent within 2 months. Some seeds continue to fall into April, and cones persist on the tree long after they are empty (18,71).

Shortleaf pine cones yield about 25 to 38 full seeds each (18,72) or about 0.9 to 1.4 kg (2 to 3 lb) of seeds per 45 kg (100 lb) of cones. The number of cleaned seeds per kilogram ranges from 70,800 to 160,700 (32,100 to 72,900 per pound) and averages 102,100 (46,300) (29). The number of seeds produced per tree and number of seeds per cone can be significantly increased by releasing seed trees from competition (71), although the number of seeds per cone may not always increase (43). The average number of cones per tree for unreleased trees was 498 compared with 1,069 for those released from competition (72). Releasing seed trees by removing hardwoods and thinning from below to densities at least as low as 11.5 m²/ha (50 ft²/acre) greatly increases seed production in shortleaf pine stands (43).

Good to excellent cone crops occur every 3 to 10 years in the Northeast and 3 to 6 years in the South (18). In the Georgia Piedmont, seed crops were most frequent in the northern portions (6). Shortleaf pine seed production was studied in natural stands in Oklahoma, Arkansas, and Missouri during a 10-year period from 1965 through 1974 (57). The lowest production was 4,900 sound seeds per hectare (2,000/acre) and the highest was 1,845,800/ha (747,000/acre). Seed yields of at least 66,700/ha (27,000/acre) occurred in 7 of the 10 years, and no consecutive 2-year periods had less than 79,100/ha (32,000/acre). In another study (72), the lowest seed production from 25 trees per hectare (10/acre) for three consecutive 3-year periods was 761,100/ha (308,000/acre).

#NAME?

Shortleaf pine's adaptability to a great variety of site and soil conditions partly accounts for its wide distribution. The best growth rate is on South Atlantic and Gulf Coastal Plain soils. However, most of the soils that shortleaf pine occupies are classed in the order Ultisols and suborder Udults. Soils in this suborder are usually moist and relatively low in organic matter in subsurface horizons. They are formed in humid climates that have short or few dry periods during the year. Two great soil groups, Paleudults and Hapludults, include the primary soils occupied by shortleaf pine. Paleudults have a thick horizon of clay accumulation without appreciable weatherable materials. Hapludults may have either relatively thin clay subsurface horizons or a subsurface horizon with appreciable weatherable materials, or both. Shortleaf pine may occupy soils in other orders, but they do not constitute a significant part of its range (58).

Shortleaf pine grows best on deep, well-drained soils having fine sandy loam or silty loam textures. These soils are found primarily on flood plains. Site indices for shortleaf pine on these sites may exceed 30 m (100 ft). Very shallow, rocky soils on upland sites in the lower rainfall sections of the species' range have very low site indices, sometimes as low as 10 m (33 ft) (21). In the upland areas of its range, site indices at base age 50 years for natural stands average between 15 m (50 ft) and 23 m (75 ft) (20,25). In north Mississippi, site indices of sample plots ranged from 6 m (20 ft) to 30 m (97 ft) for shortleaf pine plantations varying in age from 17 to 29 years (69).

Shortleaf pine does not grow well on soils with a high calcium content, high pH, or excessive internal drainage. It is also reported to be more abundant than loblolly pine on the drier, better drained, and less fertile soils in the Piedmont. The difference is partly attributable to shortleaf pine's larger root system, lower tolerance to poor soil aeration, and lower demand for nutrients (18).

Shortleaf pine grows at elevations as low as 3 m (10 ft) in southern New Jersey and up to 910 m (3,000 ft) in the Appalachian Mountains. It grows up to 300 m (1,000 ft) in Pennsylvania. Its best development is attained at elevations of 180 m (600 ft) to 460 m (1,500 ft) in the Piedmont and 45 m (150 ft) to 350 m (1,150 ft) in Louisiana and Arkansas, although it grows at elevations up to 610 m (2,000 ft) in Arkansas, Missouri, and Oklahoma (16,18).

Shortleaf pine is primarily used for lumber, plywood, other structural materials, and pulpwood. Even the taproots are used for pulpwood. The species was commonly planted on eroded lands in Mississippi (68) but does not produce as much litter as loblolly pine and therefore may be less desirable for some reclamation uses. Shortleaf pine is sometimes planted as an evergreen ornamental and as a screen in urban areas.

The seeds of shortleaf pine are eaten by birds and small mammals. Squirrels may cut the cones and eat the seeds before the cones open naturally (23). The canopies of shortleaf pine provide protection from the wind and cold for many animals. Stands of shortleaf pine scattered through hardwood forests are especially beneficial to wildlife. Older shortleaf pines with red heart rot (Phellinus pini) are primary nesting trees for the red-cockaded woodpecker (51).

Shortleaf pine can be vegetatively propagated by either rooting or grafting of scions, but techniques for production of new plants from parts such as pollen grains are lacking. Grafting of scions or twigs from special trees to trees of the same species is the most commonly used method of propagating southern pines. It is possible, but difficult, to root needle bundles and cuttings of twigs. Shortleaf pine can also be air-layered (14).

Young shortleaf pines sprout vigorously at the root collar if the crown is killed or badly damaged, a feature which probably contributes much to the species' survival where other species decline. The ability to sprout profusely is generally confined to trees up to 15 to 20 cm (6 to 8 in) in diameter. Most sprouts eventually die, leaving from one to three stems to develop. Shoots also arise from buds developing in needle fascicles below the point of injury (18).

Pinaceae -- Pine family

Edwin R. Lawson

Shortleaf pine (Pinus echinata) is one of the four most important commercial conifers in the southeastern United States. Depending upon locale, the species is also called shortleaf yellow, southern yellow, oldfield, shortstraw, or Arkansas soft pine. Shortleaf pine tolerates a wide range of soil and site conditions and maintains its growth rate for a relatively long period. However, the species tends to grow slower during the early years after establishment than other southern pines. Shortleaf pine is the most common species regenerated in the northern and western parts of its range.

Shortleaf pine has the widest range of any pine in the southeastern United States. It grows in 22 States over more than 1 139 600 km² (440,000 mi²), from southeastern New York and New Jersey west to Pennsylvania, southern Ohio, Kentucky, southwestern Illinois, and southern Missouri; south to eastern Oklahoma and eastern Texas; and east to northern Florida and northeast through the Atlantic Coast States to Delaware (33). In 1915, shortleaf pine was reported to grow in 24 States. Fossil pollen found in Michigan suggests that it may have once grown there (18).


- The native range of shortleaf pine.

Tree, Evergreen, Monoecious, Habit erect, Trees without or rarely having knees, Tree with bark rough or scaly, Young shoots 3-dimensional, Buds resinous, Leaves needle-like, Leaves alternate, Needle-like leaf margins finely serrulate (use magnification or slide your finger along the leaf), Leaf apex acute, Leaves > 5 cm long, Leaves < 10 cm long, Leaves yellow-green above, Leaves yellow-green below, Leaves grey-green, Leaves not blue-green, Needle-like leaves somewhat rounded, Needle-like leaves twisted, Needle-like leaf habit erect, Needle-like leaves per fascicle mostly 2, Needle-like leaf sheath persistent, Twigs glabrous, Twigs viscid, Twigs not viscid, Twigs without peg-like projections or large fascicles after needles fall, Berry-like cones orange, Woody seed cones < 5 cm long, Woody seed cones > 5 cm long, Seed cones bearing a scarlike umbo, Umbo with obvious prickle, Bracts of seed cone included, Seeds green, Seeds black, Seeds gray, Seeds winged, Seeds unequally winged, Seed wings prominent, Seed wings equal to or broader than body.

Pinus echinata, the shortleaf pine, is a species of pine native to the southeastern United States.