Florida Pine

Pinus palustris is fire successional, with a deep taproot and a definite grass stage. It is a valued species for lumber and pulpwood and was once important for naval stores (e.g., turpentine, pine oil, tar, pitch). It is fast disappearing over much of its natural range, partly through overharvesting but especially because of difficulties in adapting it to current plantation and management techniques.

Longleaf pine ( Pinus palustris ) is the state tree of North Carolina.

Trees to 45 m tall; trunk to 1.2 m d.b.h. in native range; bark orange-brown, with coarse, oblong, scaly plates; crown rounded; branches spreading-descending, upcurved at tips; branchlets orange-brown, aging darker brown, stout, rough; winter buds silvery white, ovoid, 3-4 cm, scales fringed at margin. Needles spreading-recurved, (2 or)3 per bundle, yellow-green, slightly twisted, 20-45 cm × ca. 1.5 mm, stomatal lines present on all surfaces, base with persistent sheath 2-2.5(-3) cm, margin finely serrulate. Seed cones solitary or paired toward branchlets tips, sessile or rarely shortly pedunculate, dark brown, ovoid-cylindric when open, 15-25 cm, maturing in 2 years, then quickly shedding seeds and falling. Apophyses dull, nearly rhombic, slightly thickened and raised, strongly cross keeled; umbo broadly triangular, with a short, stiff, reflexed prickle. Seeds pale brown, mottled darker, truncate-obovoid, ca. 1 cm; wing 3-4 cm.

Trees to 47m; trunk to 1.2m diam., straight; crown rounded. Bark orange-brown, with coarse, rectangular, scaly plates. Branches spreading-descending, upcurved at tips; twigs stout (to 2cm thick), orange-brown, aging darker brown, rough. Buds ovoid, silvery white, 3--4cm; scales narrow, margins fringed. Leaves (2)--3 per fascicle, spreading-recurved, persisting 2 years, 20--45cm ´ ca. 1.5mm, slightly twisted, lustrous yellow-green, all surfaces with fine stomatal lines, margins finely serrulate, apex abruptly acute to acuminate; sheath 2--2.5(--3)cm, base persistent. Pollen cones cylindric, 30--80mm, purplish. Seed cones maturing in 2 years, quickly shedding seeds and falling, solitary or paired toward branchlet tips, symmetric, lanceoloid before opening, ovoid-cylindric when open, 15--25cm, dull brown, sessile (rarely short-stalked); apophyses dull, slightly thickened, slightly raised, nearly rhombic, strongly cross-keeled; umbo central, broadly triangular, with short, stiff, reflexed prickle. Seeds truncate-obovoid; body ca. 10mm, pale brown, mottled darker; wing 30--40mm. 2 n =24.

Cultivated. Fujian, Jiangsu, Jiangxi (Lu Shan), Shandong (Qingdao Shi), Zhejiang [native to SE United States]

Dry sandy uplands, sandhills, and flatwoods; 0--700m; Ala., Fla., Ga., La., Miss., N.C., S.C., Tex., Va.

Pinus australis F. Michaux

Pinus australis F. Michaux; P. longifolia Salisbury.

http://www.longleafalliance.org/


The mission of The Longleaf Alliance is the restoration of the longleaf pine forest ecosystem across its range, emphasizing its economic and ecological values through research, education, and outreach.

More info for the terms: fire use, fuel

The Fire Case Study Imperata cylindrica in a Florida sandhill
longleaf pine community provides information on fuel loads, prescribed
fire use, and postfire response of juvenile longleaf pines on cogon
grass (Imperata cylindrica)-infested sites and uninfested sites.

More info for the term: swamp

longleaf pine

longstraw pine

southern yellow pine

longleaf yellow pine

swamp pine

More info for the term: natural

Only a few old-growth stands of longleaf pine remain in the southeastern
United States [43]. Although longleaf pine is not an endangered
species, many endangered plant and animal species live in longleaf pine
communities. Longleaf pine communities are ranked as threatened by the
Texas Natural Heritage Program [9].

More info for the term: seed

Longleaf pine is a long-lived, native, evergreen conifer with scaly
bark. Needles are 8 to 18 inches (20-46 cm) long; cones are 6 to 8
inches (15-20 cm) long. Mature trees attain a height of 100 to 120 feet
(30.5-36.6 m) and have the potential of living 4 to 5 centuries. The
longleaf pine seed is the largest of all southern pines. On good sites,
longleaf pine grows an 8- to 12-foot-long (2.4-3.7 m) taproot and
extensive lateral roots [7,38,54].

Longleaf pine occurs in the Atlantic and Gulf coastal plains from
southeastern Virginia to central Florida and west to eastern Texas. It
is found in the Piedmont Region and Valley-and-Ridge Province of Georgia
and Alabama [7,31].

More info for the terms: competition, fire interval, fire regime, litter, natural, root collar, seed, surface fire, tree

Longleaf pine is classified as fire-resistant [10,36]. It is ideally
suited to a high-frequency, low-severity surface fire regime. The
natural fire interval is every year to every 5 to 10 years [44]. Most
natural fires are caused by lightning and occur in late spring and
summer [37,44].

Longleaf pine has many adaptations to fire. The grass-stage seedling is
resistant to fire. If top-killed, it sprouts from the root collar.
Once the terminal bud develops, it is protected by a moist, dense tuft
of needles. As the tuft burns towards the bud from the needle tips,
water is vaporized. The steam reflects heat away from the bud and
extinguishes the fire [37,38]. The bud also has scales for protection
and a silvery pubescence that probably reflects heat [29,37].

During the grass-stage, the seedling invests heavily in a taproot and in
root collar size. When height growth is initiated, often the year after
a fire, the seedling uses its stored reserves to quickly grow a straight
stem with no branches. After one growing season, the terminal bud is
usually above the level of the next surface fire [37,38].

The bark becomes thick with age and insulates the cambium from heat.
The scaly bark dissipates heat by flaking off as it burns [37,38].

In addition to fire resistant adaptations, longleaf pine has a pyrogenic
strategy. Spring and summer fires are beneficial because they reduce
competition and expose the mineral soil necessary for seed germination
in the fall. Long, resin-filled needles have short persistence and form
a highly flammable, well-aerated litter. Resin is also concentrated in
the bole and roots of older trees and snags. These trees act as
lightning receptors. A smoldering tree can ignite the ground several
days or weeks later when the ground litter has dried out. Longleaf
pine communities often have a grass understory that readily ignites.
[28,37,43]. Because of open stands and high and open crowns, crown
fires are rare [43].

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: fuel, hardwood

Prescribed burning in longleaf pine stands is used to control brown-spot
needle blight, stimulate height growth, reduce excess fuel, control
understory hardwoods, improve wildlife habitat, thin stands, and prepare
a mineral seedbed [18,54].

Fire consumes foliage infected by brown-spot needle blight as well as
inoculum in fallen leaves [29,54]. Burning is recommended when
infection levels are greater than 20 percent and grass-stage root
collars are larger than 0.3 inches (0.8 cm) in diameter or height-growth
stage seedlings root collars are greater than 1.5 inches (3.8 cm). If
the infection rate is higher than 20 percent, a high percentage of
affected seedlings will die from the fire [18,35,45].

Annual spring fires are recommended to initiate height growth once
grass-stage seedlings are large enough to withstand fire. In the
spring, the green grass keeps the fire cool, and buds are protected by
long sheaths of needles. However, grass-stage seedlings grown on poor
sites may not tolerate light fire [12]. Once height growth begins, the
stand should not be burned for several years and then burned less
frequently [23].

Late annual spring fires are recommended to gain control of hardwoods.
Summer fires are also effective, but the risk of pine mortality is
increased [8]. Hardwoods are susceptible to fire in the late spring and
summer because root reserves are low. Once hardwood populations are
reduced, winter fire at 5-year intervals maintains longleaf pine stands,
and enables a single fire in the spring or summer before seedfall to
expose the necessary mineral soil seedbed [18,53].

Although longleaf pine regeneration is rarely excessive [2], a stand can
be thinned by fire. In Alabama, a prescribed winter fire thinned a
1-year-old stand from 177,000 seedlings per acre (437,000/ha) to 6,300
per acre (15,600/ha) [33].

Frequent late spring or early summer fires are necessary to recreate the
longleaf pine-grassland savannahs that were common in presettlement
times [44].

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More info for the term: phanerophyte

RAUNKIAER [46] LIFE FORM:



Phanerophyte

Longleaf pine grows in a warm, wet, temperate climate with an annual
precipitation of 43 to 69 inches (109-175 cm). The species occupies a
wide variety of upland and flatwood sites, but is most common on sandy,
infertile, well-drained soils. Soil types include Ultisols, Entisols,
and Spodosols. Elevations range from near sea level to 1,970 feet (600
m), although most longleaf pine grows below 660 feet (200 m) [7].

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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: cover

SAF COVER TYPES [19]:




69 Sand pine

70 Longleaf pine

71 Longleaf pine-scrub oak

75 Shortleaf pine

81 Loblolly pine

82 Loblolly pine-hardwood

83 Longleaf pine-slash pine

84 Slash pine

111 South Florida slash pine

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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):

ECOSYSTEMS [21]:




FRES12 Longleaf-slash pine

FRES13 Loblolly-shortleaf pine

FRES14 Oak-pine

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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

KUCHLER [27] PLANT ASSOCIATIONS:




K111 Oak-hickory-pine

K112 Southern mixed forest

K115 Sand pine scrub

K116 Subtropical pine forest

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This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):

More info for the terms: cover, hardwood

SRM (RANGELAND) COVER TYPES [55]:




808 Sand pine scrub

809 Mixed hardwood and pine

810 Longleaf pine-turkey oak hills

811 South Florida flatwoods

812 North Florida flatwoods

813 Cutthroat seeps

820 Everglades flatwoods

More info for the terms: crown fire, fire tolerant, litter, root collar

Open-grown grass-stage seedlings with root collar diameters smaller than
0.3 inch (0.8 cm) can be killed by light fire [7,29]. Under a pine
overstory, light fire can kill seedlings smaller than 0.5 inch (1.3 cm)
in diameter, because excess pine litter under the canopy makes the fire
hotter [3,18,44]. In a prescribed winter fire in Alabama, 1-year-old
seedlings with exposed root collars were more susceptible to fire than
seedlings with root collars at or near the soil surface [33]. Larger
grass-stage seedlings are highly resistant to fire.

In the height-growth stage, seedlings 1 to 3 feet (0.3-0.9 m) tall are
extremely vulnerable to fire [20,29]. If the terminal bud is destroyed,
the seedling will die [37]. Once a seedling is about 3.3 feet (1 m)
tall, it is likely to survive low-severity ground fires [38]. After the
sapling is 10 feet (3 m) tall, it is very fire tolerant [54]. Trees 10
inches (25 cm) in diameter and larger survive all but the most severe
fires [10]. A high-severity crown fire kills some mature trees and
nearly all trees smaller than 10 inches (25 cm) in diameter [20].

Longleaf pine needles were killed instantly when immersed in water at
147 degrees Fahrenheit (64 deg C) but survived 11 minutes at 126 degrees
Fahrenheit (52 deg C) [14].

More info for the term: seed

Longleaf pine forests provide excellent habitat for bobwhite quail,
white-tailed deer, wild turkey, and fox squirrel. Sixty-eight species
of birds utilize longleaf pine forests [45]. Birds, and mice,
squirrels, and other small mammals eat the large seeds. Ants eat
germinating seeds, and razorback hogs eat the roots of seedlings [7,54].
Old-growth longleaf pine stands provide nesting habitat for the
endangered red-cockaded woodpecker [16].

Nutritional value: Longleaf pine seed is more than 25 percent protein and more than
0.05 percent phosphorus [47].

More info for the terms: codominant, forest, mesic, shrubs, swamp, xeric

Associated hardwoods on mesic coastal plain sites include southern red
oak (Quercus falcata), blackjack oak (Q. marilandica), water oak (Q.
nigra), flowering dogwood (Cornus florida), blackgum (Nyssa sylvatica),
sweetgum (Liquidambar styraciflua), persimmon (Diospyros virginiana) and
sassafras (Sassafras albidum). Associated hardwoods on xeric sandhill
sites include turkey oak (Q. laevis), bluejack oak (Q. incana), sand
post oak (Q. stellata var. margaretta), and live oak (Q. virginiana) [7].

Associated shrubs include gallberry (Ilex glabra), yaupon (I.
vomitoria), large gallberry (I. coriacea), wax-myrtle (Myrica
cerifera), shining sumac (Rhus copallina), blueberry (Vaccinium spp.),
huckleberry (Gaylussacia spp.), blackberry (Rubus spp.), saw palmetto
(Serena repens), sweetbay (Magnolia virginiana), swamp cyrilla (Cyrilla
racemiflora), and buckwheat-tree (Cliftonia monophylla) [7].

In longleaf pine's western range, groundcover includes bluestem
(Andropogon spp.) and panicum (Panicum spp.). In its eastern range,
pineland threeawn or wiregrass (Aristida stricta) is the primary
groundcover [7].

The published classifications listing longleaf pine as a dominant or
codominant species in community types (cts) are presented below:

Area                         Classification                 Authority



e TX, LA, MS          general veg. cts              Bridges & Orzell 1989

AL                            forest cts                       Golden 1979

SC                            veg. cts                         Nelson 1986

se US; Gulf Coast      general forest cts           Pessin 1933

se US                        general forest cts           Waggoner 1975

NC                            veg. cts                         Wells 1928

More info for the term: tree

Tree

More info for the terms: basal area, cone, density, forest, natural, seed, selection, tree

Longleaf pine communities are estimated to have once covered 59 to 87
million acres (24-35 million ha); now only 5 to 10 million acres (2-4
million ha) remain. Of that remaining, most is second growth and
in poor condition [40,41]. Because of its timber value and because longleaf
pine communities house many endangered plant and animal species, forest
managers are attempting to regenerate more longleaf pine communities.

Natural regeneration of longleaf pine is difficult because of poor seed
production, heavy seed predation by animals, poor seedling survival, and
slow seedling growth. Longleaf pine is best managed with even-aged
silviculture using a three-cut shelterwood system [2,5,18,25]. The
preparatory cut, 10 years before expected seed crop, should leave a
basal area of 60 to 70 square feet per acre (13.8-16.1 sq m/ha). The
remaining trees will develop larger crowns and increase seed production.
The seed cut, 5 years before the expected seed crop, should leave a
basal area of 30 square feet per acre (6.9 sq m/ha). The seedbed should
be prepared, usually with fire, when a good seed crop is evident from
large numbers of conelets. Seed trees should be removed 1 to 2 years
after seedlings are established and before height growth has been
initiated [5,25].

The group selection method can be used to naturally regenerate
uneven-aged stands. Up to 2 acres (0.8 ha) of trees should be cut so
discernible openings are created [2].

Methods for artificial regeneration of longleaf pine are detailed in
Rounsaville 1989 [45].

Disease and insects: Longleaf pine is highly resistant to most diseases
and insects that infect other southern pines. The main disease of
longleaf pine is brown-spot needle blight (Scirrhia acicola).
Defoliation suppresses and eventually kills grass-stage seedlings [7].
Infection of seedlings is less severe under a pine overstory than in the
open [4]. About 20 percent of seedlings are resistant to brown-spot
needle blight [17]. (See Fire Management).

Other diseases include pitch canker (Fusarium moniliforme var.
subglutinans), annosus root rot (Heterobasidion annosum), and cone rust
(Cronartium strobilinum). Insects that attack longleaf pine include
black turpentine beetle (Dendroctonus terebrans), bark beetles (Ips
spp.), and seed bugs (Tetyra bipunctata and Leptoglossus corculus),
which can decimate a seed crop [7].

Predation: Despite fall germination, which minimizes the time seed lies
on the forest floor, predation by birds and small mammals can decimate a
seed crop [18].

Weather: Because of the fall germination, low winter temperatures can
damage cotyledons. March frosts can destroy flowers. Hurricanes,
tornadoes, and lightning cause local damage [7,18].

Other considerations: Moderate cattle grazing has no effect on longleaf
survival, but heavy grazing reduces young tree density by 20 percent
[54]. Hogs significantly reduce longleaf pine establishment and can
cause crop failure [30].

Longleaf pine's needles are used for mulch. Resin is used in the
naval stores industry for gum turpentine and rosin production [7].

Wood Products:
Longleaf pine, a valued timber species, has clear, straight wood with
few defects [18]. It was used extensively in the past for timber and
ship building. Most virgin stands have now been harvested. Because
longleaf pine is not as easy to regenerate as other southern pine timber
species, it is not used as extensively as it once was. Longleaf pine's
highly desirable wood, however, has stimulated efforts to regenerate it
[7,18].

More info on this topic.

More info for the term: seed

Longleaf pine seed develops in a 3-year process. Strobili are initiated
during midsummer. Conelets emerge in late winter. Catkins emerge in
November, then remain dormant until late winter. Pollination occurs
from late February in the South to early April in the North.
Fertilization does not occur until the following spring. Cones reach
maturity in mid-September to mid-October after their second season of
growth. Seed is dispersed from late October to November and the
majority of seed falls in 2 to 3 weeks. Seed germinates 1 to 2 weeks
later. Primary needles appear soon after germination and secondary
needles about 2 months later [7,18].

More info for the terms: basal area, competition, seed

Fire can stimulate height-growth initiation of grass-stage seedlings.
After three annual spring fires in Louisiana, most grass-stage seedlings
had initiated height growth. It is thought that height growth is
initiated because fire reduces competition and brown-spot needle blight
infection. Late spring or summer fires are more effective at promoting
height growth than winter fires [12,13,23]. However, annual fires begun
only 1 year after germination stunt height growth [20].

Once a seedling has entered the height-growth stage, fire damage can
decrease growth. Annual fires have reduced basal area growth of young
longleaf pine by 22 to 44 percent [54]. In Alabama, prescribed biennial
fires begun in 14-year-old stands averaging 22 feet (6.7 m) in height
and 3.2 inches (8.1 cm) in diameter reduced growth, even though no crown
scorch was observed. The impact on growth of biennial fires worsened
with time. The season of fire had no effect [6].

Older longleaf pine shows no growth loss if there is little or no needle
scorch [29]. Seed production of mature trees is not affected by
frequent fire.

Seed will germinate on mineral soil exposed by fire [7].

Trees in regularly burned stands develop a buttressed trunk which
results in stump taper [1].

More info for the term: seed

POSTFIRE REGENERATION STRATEGY [56]:




Crown-stored residual colonizer; short-viability seed in on-site cones

Off-site colonizer; seed carried by wind; postfire years one and two

More info for the terms: competition, cone, epigeal, litter, monoecious, root collar, seed, tree

Seed production and dissemination: Longleaf pine is monoecious. It
begins producing cones when it reaches about 30 years of age or 10
inches (25 cm) in diameter [18,38]. The best cone producers are
15-inch-diameter (38 cm) open-grown trees. Cones contain, on average,
35 seeds [7]. Longleaf pine masts every 7 to 10 years, but healthy
trees will produce a fair to good seed crop every 3 to 4 years
[2,37,38]. The winged seeds are dispersed a short distance by wind with
71 percent of the seeds falling within 66 feet (20 m) of the base of the
parent tree [7].

Germination and seedling development: Seeds germinate 1 to 2 weeks
after seedfall. Germination is epigeal and requires mineral soil. The
seed's large size and persistent wing prevent it from penetrating
through the litter. Seedlings are stemless after one growing season and
this "grass-stage" lasts from 2 to many years [7,18,38]. It may last as
long as 20 years if brown-spot needle blight or competition is severe
[18,45]. During the grass-stage, the seedling develops an extensive
root system, and the root collar increases in diameter. When the root
collar diameter approaches 1 inch (2.5 cm) in diameter, height growth
begins. An open-grown seedling grows 10 feet (3 m) in 3 years once
height growth is initiated [7,37,54]. Branch production is delayed
until the seedling reaches 10 to 16 feet (3-5 m) in height [43].

Vegetative reproduction: If grass-stage seedlings are top-killed, they
can sprout from the root collar. Once height growth begins, sprouting
ability decreases rapidly [7].

(key to state/province abbreviations)




AL      FL      GA      HI      LA      MS      NC      SC      TX      VA

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More info for the term: competition

Longleaf pine is intolerant of shade and competition. With frequent
fire, uneven-aged pure stands of longleaf pine form parklike savannahs
[7,20,37]. Because longleaf pine regenerates in openings created by the
death of mature trees, small clusters of trees of the same age are
dispersed throughout the stand [43]. In the absence of frequent fire,
longleaf pine is replaced by hardwoods and other southern pines [7,54].
Loblolly pine and shortleaf pine will invade and soon dominate a site of
grass-stage longleaf pine [11]. Recruitment of longleaf pine ceases 15
years after fire. Invasion by hardwoods accelerates the decline of
mature longleaf pine [24].

Longleaf pine is classified as a fire subclimax [18,19,20,45].
Lightning, which historically ignited the frequent fires, is a component
of a long-term climatic pattern. As long as there is lightning,
longleaf pine can perpetuate itself indefinitely on a site.

Pinus australis Michx.

More info for the term: natural

The currently accepted scientific name of longleaf pine is Pinus
palustris Mill. [7,31]. There are no recognized varieties or subspecies.
Longleaf pine forms natural hybrids with loblolly pine (P. taeda) and
slash pine (P. elliottii), although the latter are rare [7,26].

Longleaf pine is recommended for reforestation of dry, infertile, deep
sands in the southeastern United States. Most of these sites were
formerly longleaf pine forests but were invaded by scrub oaks (Quercus
spp.) after timber harvesting [48]. Longleaf pine is of limited use for
rehabilitation of mine spoils in Alabama [50].

The principal longleaf cover types are Longleaf Pine (Society of American Foresters Type 70), Longleaf Pine-Scrub Oak (Type 71), and Longleaf Pine-Slash Pine (Type 83) (12). Longleaf pine is also a minor component of other forest types within its range: Sand Pine (Type 69), Shortleaf Pine (Type 75), Loblolly Pine (Type 81), Loblolly Pine-Hardwoods (Type 82), Slash Pine (Type 84), and South Florida Slash Pine (Type 111).

Longleaf pine develops in close association with periodic surface fires. The vegetation associated with longleaf pine reflects the frequency and severity of burning. In the past, frequent fires resulted in open, parklike stands of longleaf with few other woody plants and a ground cover dominated by grasses. Ground cover in longleaf pine in the Coastal Plains can be separated into two general regions, with the division in the central part of south Alabama and northwest Florida. To the west, bluestem (Andropogon spp.) and panicum (Panicum spp.) grasses predominate; to the east, wiregrass (pineland threeawn, Aristida stricta) is most common.

With a reduction in fire occurrence, hardwoods and other pines encroach on the longleaf forest. Within the range of slash pine (Pinus elliottii), this species becomes increasingly important, leading to the cover type Longleaf Pine-Slash Pine. Elsewhere loblolly and shortleaf pines (P. taeda and P. echinata) as well as hardwoods gradually replace the longleaf, eventually resulting in Loblolly Pine-Hardwood (Type 82) or occasionally Loblolly Pine-Shortleaf Pine (Type 80). On poor, dry sandhills and mountain ridges, scrub hardwoods invade the understory creating forest cover type Longleaf Pine-Scrub Oak and finally Southern Scrub Oak (Type 72) as the pine disappears (12).

Hardwoods most closely associated with longleaf pine on mesic Coastal Plain sites include southern red, blackjack, and water oaks (Quercus falcata, Q. marilandica, and Q. nigra); flowering dogwood (Cornus florida); blackgum (Nyssa sylvatica); sweetgum (Liquidambar styraciflua); persimmon (Diospyros virginiana); and sassafras (Sassafras albidum). The more common shrubs include gallberry (Ilex glabra), yaupon (I. vomitoria), southern bayberry (Myrica cerifera), shining sumac (Rhus copallina), blueberry (Vaccinium spp.), huckleberry (Gaylussacia spp.), and blackberry (Rubus spp.). On xeric sandhill sites, the most common associates are turkey, bluejack, blackjack, sand post, and dwarf live oaks Quercus laevis, Q. incana, Q. marilandica, Q. stellata var. margaretta, and Q. minima). On the dry clay hills and mountains of Alabama, blackjack, post (Q. stellata) and southern red oaks, and mockernut hickory (Carya tomentosa) are found with longleaf pine. On low, wet flatwood sites near the coast, the most conspicuous understory plants are gallberry and saw-palmetto (Serenoa repens). Other common understory plants in low, wet Longleaf Pine or Longleaf Pine-Slash Pine types are sweetbay (Magnolia virginiana), swamp cyrilla (Cyrilla racemiflora), large gallberry (Ilex coriacea), buckwheat-tree (Cliftonia monophylla), blueberries, and blackberries.

Longleaf pine grows in warm, wet temperate climates characterized by hot summers and mild winters. Annual mean temperatures range from 16° to 23° C (60° to 74° F) and annual precipitation from 1090 to 1750 mm (43 to 69 in), the least being 1090 to 1270 mm (43 to 50 in) in the Carolinas and Texas and the greatest along the Gulf Coast of Alabama, Mississippi, and extreme west Florida. A distinct summer rainfall peak occurs along the Atlantic Coast, being most pronounced in Florida. A secondary rainfall peak in March becomes pronounced along the Gulf Coast. Fall is the driest season of the year, although droughts during the growing season are not unusual.

Longleaf pine is less susceptible to most damaging agents than the other southern pines and is a relatively low risk species to manage. It is strongly resistant to fire, except as a small seedling of less than 0.8 cm (0.3 in) root collar diameter and in early height growth. It is also resistant to most pathogenic agents. The major disease is the brown-spot needle blight. This disease causes serious damage only to grass-stage seedlings. Continued severe defoliation by brown-spot suppresses and eventually destroys seedlings. Once rapid height growth begins, seedlings are no longer seriously afflicted. Seedlings growing in the open are most vulnerable, particularly if the groundcover is sparse; the disease usually does not seriously affect seedlings growing under a pine overstory. Other diseases occasionally of economic importance in local areas are pitch canker (Fusarium moniliforme var. subglutinans), annosus root rot (Heterobasidion annosum) in thinned plantations, cone rust (Cronartium strobilinum) near the coast, and also the condition known as dry face of turpentined trees. Fusiform rust (Cronartium quercuum f. sp. fusiforme) is rarely a problem for longleaf pine (20).

Many species of birds, mice, and squirrels feed on longleaf pine seeds, the latter often taking them from unripe cones. Several species of ants feed on germinating seeds and cotyledon seedlings. Cottontails as well as other predators can destroy newly established seedlings. Grass-stage seedlings are vulnerable to destruction by hogs, pales weevil (Hylobius pales), and heavy livestock grazing. Pocket gophers cut seedlings off just below the ground surface.

Most seedling losses occur during the first year after establishment, untimely drought being the greatest single hazard. Logging of the overstory can destroy close to 50 percent of a seedling stand, although actual damage depends on type and season of logging, volume removed, and seedling size. Fire takes its toll of small, weak, or diseased seedlings.

Longleaf pine can be damaged by ice storms but is less susceptible to ice damage than slash pine (19).

The southern pine beetle (Dendroctonus frontalis) does not seem to afflict the species severely. The black turpentine beetle (Dendroctonus terebrans) can be a problem, especially on trees injured by turpentining, logging, or fire. Perhaps the greatest single cause of mortality in longleaf stands of pole and sawlog size is lightning, which is often followed by infestation by bark beetles (Ips spp.). Windthrow from hurricanes or tornados can cause heavy losses locally. Long term observations throughout the longleaf region have shown an average annual mortality of 1 tree per hectare (0.4/acre) in mature longleaf pine stands (4).

Like all species in the pine family, longleaf pine is monoecious. The strobili of longleaf pine, both male (catkins) and female (conelets), are initiated during the growing season before buds emerge. Catkins may begin forming in July, while conelets are formed during a relatively short period of time in August. The number of flowers produced is apparently related to weather conditions during the year of initiation. A wet spring and early summer followed by a dry period in late summer promotes conelet production (27). Catkin production, however, is favored by abundant rainfall throughout the growing season. Female strobili are borne most frequently in the upper crown, and male strobili predominate in the lower crown (26). Late summer rainfall depresses conelet initiation, probably because vigorous exposed shoots in the middle and upper crown continue to grow. In the lower crown, where most catkins are home, shoots stop growing earlier than they do in the upper crown.

Since rainfall patterns associated with catkin initiation differ from those favoring conelets, large crops of male and female flowers do not necessarily coincide. Ten years of observation did not show any correlation between size of conelet and pollen crops in longleaf pine.

Variable but usually heavy annual losses of longleaf pine conelets can be expected; observed losses have ranged from 65 to 100 percent (2,24,30). Several agents, alone or in combination, may be responsible. The more important appear to be insects, bad weather, and insufficient pollen. Over 15 years at one location, cone production was related to pollen density, to the point of a sufficiency of pollen (2). Further increases in pollen density had little effect. In some cases, nearly all the losses have been attributed to insects (24), while in others the more common causes of conelet losses were not responsible (30). Most conelet losses seem to occur in the spring, at about the time of pollination, although substantial losses may also occur in the summer (24). Most of the spontaneous conelet abortions in longleaf pine may result from excess ethylene production by foliage and shoots. A foliar spray with anti-ethylene compounds soon after anthesis has reduced conelet abortion by half, doubling seed yields (18).

Catkin buds normally emerge in November, then remain dormant for about a month before growth resumes. Conelet buds emerge in January or February. The rate of development of both conelets and catkins thereafter is almost entirely dependent on ambient temperature. Catkins are purple from the time they emerge from the buds until they shed their pollen. Upon emerging from the bud, conelets are red until they are pollinated, after which they gradually fade to a yellowish green. Most mature catkins range from 3 to 5 cm (1.2 to 2.0 in) in length.

The average date of peak pollen shed and conelet receptivity may range from late February in the southern part of longleaf pines' range to early April toward the northern limits. Most locations may experience flowering dates close to these extremes. The date of peak pollen shed and conelet receptivity coincides on individual longleaf pine trees but can vary considerably among trees in a stand. Some trees are consistently early and others late in time of flowering, although the differences vary from year to year, depending on air temperatures before and during the flowering period (5). Over 22 years of observation, the time required for shedding 80 percent of all pollen in a longleaf pine stand ranged from 5 to 21 days and averaged 13 (5).

Pollination takes place in the late winter or spring, but fertilization does not occur until the following spring. At this time conelets are growing rapidly, increasing in length from about 2.5 cm (1 in) in February to about 18 cm (7 in) by May or June (16). Mature cones range in length from 10 to 25 cm (4 to 10 in). Cones reach maturity between mid-September and mid-October of their second year. Cones, as they become ripe, change color from green to dull brown, although cones may be ripe before the color change (26). The specific gravity of ripe cones ranges from 0.80 to 0.89. Ripeness can be tested by flotation in SAE 20 motor oil; ripe cones will float but those not yet ripe will sink (26).

Population Differences Longleaf pine is a highly variable species, and a considerable proportion of this variation is genetic. Considering the economically important traits, longleaf pines have as much or more genetic variation than other southern pines.

Variation among individual trees is greater than that among stands or among geographically diverse seed sources (23,28). Nevertheless, the diversity of environments throughout the longleaf range has promoted the development of genetic variation among populations. According to rangewide provenance tests, trees from coastal areas usually outgrow those from inland areas at all but the coldest locations. Trees originating from the central Gulf Coast should be more productive than trees from other sources on most coastal plain longleaf sites from Georgia and north Florida west to east central Louisiana (28). Elsewhere, local seed sources may be safest to use until more information is available.

Hybrids The major southern pines, as well as some minor species, are closely related and have overlapping ranges. Natural hybridization has contributed to genetic diversity among trees and populations. Natural hybridization is common between longleaf and loblolly pine, producing the Sonderegger pine (P. x sondereggeri H. H. Chapm.). This is the only named southern pine hybrid. Throughout much of the longleaf pine range, the flowering of longleaf and loblolly pines overlaps in most years so there is no phenological barrier to natural crossing. Natural hybridization between longleaf and slash pine is unlikely, based on differences between the species in dormancy and heat requirements for flowering (5).

Artificial crosses between longleaf pine and both loblolly and slash pines can be achieved easily. Crosses between longleaf and shortleaf pine have not been found in nature but have been produced artificially. There are no reported successful crosses of longleaf pine with any other pine species (28).

Longleaf pine is a high quality timber tree, well suited to a whole range of products-poles, piling, posts, sawlogs, plywood, pulpwood, and naval stores. Longleaf naturally prunes itself well. Most stems are well formed, straight, and largely free of branches. The species almost always has higher stemwood specific gravities and produces more dry wood per unit volume than either loblolly or slash pine (28). Intense exploitation since colonial days, plus lack of planned regeneration, contributed to the decline of longleaf pine forests that continues to this day. Once height growth has begun, the species can grow as well as the other major southern pines on many sites originally occupied by longleaf, and often exceeds them in growth.

The critical element in the growth of longleaf pine stands is the duration of the grass stage. About 70 percent of the variation among plantations in the form of height-over-age curves was related to the condition of the planting site: early height growth on unprepared cutover sites was much slower than on old fields and mechanically prepared cutover sites (6).

Reduction of competing ground cover in grass stage seedling stands can have a large impact on growth and future volume yields. One study (25) observed the effects of a single aerial application of 2,4,5-T to stands of 1-year-old longleaf seedlings. Twenty years later, treated stands had significantly greater tree diameter (10 percent), height (17 percent), and total volume per unit area (32 percent) than adjacent untreated stands, although there was no difference in the number of trees per unit area. Treated stands averaged 83.5 m³/ha (1,193 ft³/acre) total inside-bark (i.b.) volume, compared to 63.2 m³/ha (904 ft³/acre) for untreated stands.

Longleaf pine growth and yield predictions have been published for periodically thinned even-aged natural stands (15) and also for unthinned plantations in the west Gulf region (22). Predicted total volume (i.b.) yields for two common site index classes are given in table 1. The merchantable proportion of total volume ranges from 78 to 86 percent at age 20, to 97 to 98 percent at age 40. The peak in periodic annual increment is reached between ages 20 and 30.

Table 1- Predicted total volume yields inside bark for even-aged natural stands of longleaf pine Site index at base age 50 years Stand in age in years¹
Basal area
21.3 m or 70 ft
24.4 m or 80 ft m²/ha m³/ha m³/ha 20 13.8   61   71 25 20.0 110 128 30 25.5 160 187 35 29.6 207 241 40 33.1 248 289 ft²/acre ft³/acre ft³/acre 20   60    874 1,019 25   87 1,572 1,832 30 111 2,287 2,666 35 129 2,954 3,443 40 144 3,549 4,137 ¹Determined from ring counts taken at 1.2 m (4 ft), plus 7 years. The optimum stand density to maintain by periodic thinning varies by site and management goals. A rather broad range of stand densities, above a basal area of about 13.8 m²/ha (60 ft²/acre), produces near maximum periodic volume growth (13). Lower densities concentrate growth on fewer trees. Longleaf responds well to release provided by thinning if the released trees have crowns equal to at least one-third to one-half of total tree height. Small-crowned intermediate or suppressed trees do not respond promptly to release. Thinning should be from below to release well-formed dominant and codominant trees.

Present indications are that longleaf pine plantations should produce volume growth similar to natural stands if other factors are equal. To the extent that plantations have had better competition control, with consequent acceleration of early growth, a particular volume yield should be reached at an earlier age in plantations than in natural stands.

Longleaf pine is intolerant of competition, whether for light or for moisture and nutrients. The species will grow best in the complete absence of all competition, including that from other members of the species. Fortunately, as noted earlier, young even-age longleaf pine stands break up rapidly into a broad range of size classes, due to variability in duration of the grass stage. Stagnation is almost never a problem. However, even suppressed trees in a stand will slow the growth of dominant neighbors. Optimum stand density for development of crop trees needs to be maintained by periodic thinning. Given release from neighboring trees, dominant and codominant trees in an over-dense stand will respond promptly with increased diameter growth, as will some intermediate trees that retain crown ratios of 30 percent or more. Suppressed trees, while they may continue to live, rarely respond to release with improved growth.

Longleaf pine develop massive taproots that, in mature trees, may extend to a depth of 2.4 to 3.7 m (8 to 12 ft) or more. A hardpan can arrest downward growth of the taproot. If the hardpan is close to the surface, windfirmness of the tree is reduced. Longleaf pines develop extensive lateral root systems. Most lateral roots are within 0.3 m (1 ft), and nearly all within 0.6 m (2 ft), of the surface (29).

Tree size, crown class, stand density, site quality, and, most important, genetic predisposition, all affect cone production by an individual tree. The best cone producers are dominant, open grown trees with large crowns, 38 cm. (15 in) or more in d.b.h., with a past record of good cone production (11). Trees 38 to 48 cm (15 to 19 in) in d.b.h. have produced an average of 65 cones annually compared to 15 cones by trees from 25 to 33 cm (10 to 13 in) in d.b.h. The number of sound seeds per cone varies widely and is related to size of seed crop in a particular year. In good seed years there may be about 50 seeds per cone, in average years 35, and in poor years 15 (10).

Seed production per hectare reaches a peak at stand densities between 6.9 and 9.2 m²/ha (30 to 40 ft²/acre) of basal area, assuming that the stand is comprised of dominant-codominant trees of cone bearing size (3). A shelterwood stand with a basal area of 6.9 m²/ha (30 ft²/acre) produces three times as many cones per unit area as a stand of scattered seed trees averaging 2.3 m²/ha (10 ft²/acre) in good seed years (11).

Throughout its range, longleaf pine in shelterwood stands produces seed crops adequate for natural regeneration, about 2,500 cones per hectare (1,000/acre), on the average of once every 4 to 5 years (11). However, everything else being equal, good cone crops are more frequent in some parts of the longleaf pine range than in others, so the general average may be meaningless at a given location. The production of female strobili is much less variable from place-to-place than is the production of mature cones, indicating that geographic differences in cone production are due more to conelet and cone losses than failure to produce conelets in the first place (7).

When a shelterwood stand is created by cutting back a stand of substantially higher density, increased cone production resulting from release does not occur until the end of the third growing season after cutting (9). Release that occurs after conelet initiation has no effect on that crop, other than promoting better conelet survival through reduced stress in dry periods.

Seeds are dispersed by the wind. Seed dispersal begins in late October and continues through November, with the majority falling within a period of 2 to 3 weeks. The time and duration of seed dispersal vary depending on weather conditions. Dispersal range is limited, with 71 percent of sound seeds falling within a distance of 20 m (66 ft) of the base of parent trees (11).

Longleaf seeds are the largest of the southern pines. The number of cleaned seeds ranges from 6,600 to 15,400/kg (3,000 to 7,000/lb), averaging 10,800/kg (4,900/lb) (26).

Longleaf pine differs from other southern pines in that seeds germinate soon after they are dispersed. Given optimum conditions, seeds germinate in less than a week after they reach the ground. Prompt germination reduces the period of exposure to seed predators, but newly germinated seedlings are susceptible to damage or loss from animals, diseases, and weather uncertainties, which may include high fall temperatures, drought, or extreme cold with a risk of frost heaving in heavy soils (11).

Seeds require contact with mineral soil for satisfactory germination and establishment. Longleaf seeds, with their large wings, cannot easily reach mineral soil through a heavy cover of grass and litter. The accumulated material must be removed before seedfall, either mechanically or by burning. Burning within a year of seedfall normally provides an adequate seedbed. Lack of seedbed preparation can result in a regeneration failure.

Germination of longleaf pine seed is epigeal (26). Newly germinated seedlings have virtually no above-ground hypocotyl, and the cotyledons are close to the ground line. The primary needles appear after germination and the secondary needles about 2 months later. The epicotyl, or stem above the cotyledons, does not elongate rapidly as in most other pines. Even in the nursery, seedlings are virtually stemless after one growing season (16). This stemless condition is one of the unique characteristics of longleaf pine. It is referred to as a grass stage and may last 2 to many years, depending on growth conditions. During this time, longleaf is most susceptible to its major disease, the brown-spot needle blight, Scirrhia acicola (11).

While in the grass stage, seedlings develop extensive root systems. Growth can be followed by observing the increase in root-collar diameter. When it approaches 2.5 cm (1 in), active height growth is imminent. Grass-stage seedlings, once they reach 0.8 cm (0.3 in) in root-collar diameter, are highly resistant to fire, even during the growing season. Seedlings in early height growth, up to a height of about 0.6 to 0.9 m (2 to 3 ft), become susceptible to damage by fire. Once beyond this stage, longleaf pines are again fire resistant.

Competition and brown-spot needle blight have great impact on the rate of seedling development and together largely determine the duration of the grass stage. Longleaf seedlings can be easily established and usually survive for years under an overstory of parent pines. Growth, however, is very slow. Seedlings respond promptly with an increased rate of growth when released from overstory competition.

Growth rate varies widely among individuals in a natural seedling stand, and vigorous fast-growing seedlings express dominance early. The rapid breakup of a seedling stand into a wide range of size classes reduces the risk of stand stagnation. About 10 percent of a natural seedling stand shows resistance to the brown-spot disease, and this gives them a growth advantage that persists for many years. At age 24, trees that had little or no brown-spot infection averaged 2.4 in (8 ft) taller than trees that had 30 percent or more of their foliage destroyed by the disease as seedlings (1).

A low level of competition permits early initiation of height growth. One longleaf pine plantation on a prepared site had nearly 60 percent of the trees in active height growth by the end of the second growing season, and over 90 percent by the end of the third. Early initiation of height growth circumvented a brown-spot problem as the disease did not have time to build up to serious proportions.

Longleaf pine is native to a wide variety of sites ranging from wet, poorly drained flatwoods to dry, rocky mountain ridges. Elevations range from barely above sea level near the beaches on the lower Coastal Plain up to about 600 m (1,970 ft) in the mountains of Alabama. Most of the longleaf pine forests are found on the Atlantic and Gulf Coastal plains at elevations below 200 m (660 ft). Here the soils are largely derived from marine sediments and range from deep, coarse, excessively drained sands to poorly drained clays. For the most part, surface soils are sandy, acid, low in organic matter, and relatively infertile. In the Mountain Province, soils are derived largely from granite, quartzite, schist, phyllite, and slate, while in the Ridge and Valley Province, soils are derived mostly from sandstone, shale, limestone, and dolomite (21).

Within the natural range of longleaf pine, three soil orders are of major importance. Ultisols are the dominant order and cover most of the southeastern United States outside of peninsular Florida. Ultisols most commonly associated with longleaf pine are the Typic Paleudults and Plinthic Paleudults. The other two soil orders are Entisols and Spodosols. Deep, sandy Entisols, primarily Quartzipsamments, range from about 3 m (10 ft) above sea level in Florida up to about 185 m (600 ft) in Georgia and the Carolinas. Entisols have not developed diagnostic horizons. They make up the Sandhills of the Carolinas, Georgia, and northwest Florida and the sand ridges in the central Highlands of peninsular Florida. Spodosols, particularly Aquods, are typical of the flatwoods of the lower Coastal Plain in Florida. They are wet, sandy soils with a fluctuating water table that is at or near the surface during rainy seasons (8).

Longleaf pine is used for a broad range of forest products. Even old lightered stumps (those having resin-soaked heartwood characteristic of old trees) are pulled out and the stumpwood destructively distilled for chemicals. Longleaf "pine straw" is in demand for use as a mulch, so fresh needle litter is sometimes collected, baled, and sold. The longleaf pine forest, if regularly burned, has a parklike appearance with an understory dominated by grasses and forbs; an excellent habitat for game, especially quail, and quail hunting has long been associated with this timber type. The understory produces a substantial amount of high quality forage for both cattle and deer (17,31). Mature longleaf stands also provide the most desirable habitat for the red-cockaded woodpecker.

Longleaf pine seedlings, if top killed, can sprout from the root collar. Sprouting ability decreases sharply when seedlings begin height growth. In one study, almost 40 percent of seedlings cut off at the ground line during grass stage had living sprouts a year later. Only 14 percent of seedlings up to 1.37 m (4.5 ft) in height so treated developed sprouts, however, and those larger than this did not sprout at all (14). Longleaf is not as easy to reproduce asexually as some of the other southern pines. Cuttings can be rooted but the process is difficult. Air-layering has met with limited success. Grafting has proven to be a reliable technique, and this is now the most common method of establishing seed orchards (28).

Pinaceae -- Pine family

W. D. Boyer

Longleaf pine (Pinus palustris), whose species name means "of the marsh," has been locally referred to as longstraw, yellow, southern yellow, swamp, hard or heart, pitch, and Georgia pine. In presettlement times, this premier timber and naval stores tree grew in extensive pure stands throughout the Atlantic and Gulf Coastal Plains. At one time the longleaf pine forest may have occupied as much as 24 million ha (60 million acres), although by 1985 less than 1.6 million ha (4 million acres) remained.

The natural range of longleaf pine includes most of the Atlantic and Gulf Coastal Plains from southeastern Virginia to eastern Texas and south through the northern two-thirds of peninsular Florida. The species also grows in the Piedmont, Ridge and Valley, and Mountain Provinces of Alabama and northwest Georgia.


- The native range of longleaf pine.

Tree, Evergreen, Monoecious, Habit erect, Trees without or rarely having knees, Tree with bark rough or scaly, Young shoots 3-dimensional, Buds not 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 not blue-green, Leaves white-striped, Needle-like leaves triangular, Needle-like leaves twisted, Needle-like leaf habit drooping, Needle-like leaves per fascicle mostly 3, 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, Seed cones bearing a scarlike umbo, Umbo with obvious prickle, Bracts of seed cone included, Seeds brown, Seeds winged, Seeds unequally winged, Seed wings prominent, Seed wings equal to or broader than body.

The longleaf pine (Pinus palustris) is a pine species native to the Southeastern United States, found along the coastal plain from East Texas to southern Virginia, extending into northern and central Florida. In this area it is also known as "yellow pine" or "long leaf yellow pine", although it is properly just one out of a number of species termed yellow pine. It reaches a height of 30–35 m (98–115 ft) and a diameter of 0.7 m (28 in). In the past, before extensive logging, they reportedly grew to 47 m (154 ft) with a diameter of 1.2 m (47 in). The tree is a cultural symbol of the Southern United States, being the official state tree of Alabama. Contrary to popular belief, this particular species of pine is not officially the state tree of North Carolina.