Swamp pine ( Pinus palustris )
The Pinus palustris ( Pinus palustris , too) resin pine called, is a plant from the genus of pine trees ( Pinus ) within the family of the Pinaceae (Pinaceae). It occurs in the southeastern US states. It bears the common English names Longleaf Pine, Southern Yellow Pine, Georgia Pine or earlier Pitch Pine, which led to confusion with the pitch pine ( Pinus rigida ) of the same name . It serves as a landmark for the US states of Alabama and North Carolina . It is one of the most conspicuous and economically important tree species in the American southern states.
Description and ecology
The swamp pine grows as a tree that reaches heights of 24 and 37 meters and chest height diameters of 61 to 76 centimeters. The relatively short crown is open and the branches are at right angles from the straight trunk. The strong young shoots are quite flexible. Depending on the weather conditions of the growing season, shoots with one, in extreme cases five to six, intermediate whorls are formed. The terminal shoots only go through one to three growth spurts per summer.
Root system and symbiosis
The marsh pine forms a strong taproot system that can penetrate deep substrates up to 3.7 meters. Solidified substrates will not grow through. The lateral root system focuses on the top 60 centimeters. The species is endangered by wind throws on solidified sites near the surface. After around 7 days, the root of the seedlings has reached a length of around 6 centimeters. An ectomycorrhiza with the common pea litter ( Pisolithus arhizus ) improves the growth of the seedlings and increases their survival rate.
Young trees have deeply cracked, gray bark . Old trees have an uneven, almost orange-brown plate bark separated by shallow furrows with an ivory-colored cork layer . Young shoots are orange-brown in color and covered with scales.
A morphological peculiarity of the species Pinus palustris is the so-called “grass stage” of the seedlings . The seedlings form such a short hypocotyl that the cotyledons are just above the ground. Shortly after the cotyledons, the primary needles appear on a 3 to 7 millimeter long epicotyledon . The first short shoots with secondary needles appear around 2 months later. Due to the late development of the secondary needles, the seedlings look like they are only made of needle. Although growth in height and thickness is limited, during the grass stage the seedlings develop a vigorous terminal bud , an extensive root system, and a greatly dilated root neck. The grass stage ends after around 2 years under favorable conditions, but under unfavorable conditions it can last up to 20 years. Seedlings that have reached a height of 15 to 80 centimeters are already very resistant to fire.
Buds and needles
The large and showy winter buds have silvery white and ciliate bud scales.
The light green needles stand in threes on short shoots and are surrounded by a 1.5 to 3.8 centimeter long needle sheath. In cross-section, the needles are triangular, 20 and 45 centimeters long and have 4 to 7 resin channels . Can be found on all sides of stomata . The edges are imperforated and the needle point is pointed. The needles are usually clustered in clusters at the branch ends. They fall off at the end of the 2nd growing season.
Flowers, cones and seeds
Depending on the location, the flowering period extends from mid-February to early April. The flowers are created in July and August of the previous year. The weather conditions at the time of flowering play a decisive role in the number of flowers formed. While male cones are encouraged by copious rainfall during the growing season, warm spring, early onset of summer, and dry late summer encourage the formation of female cones. Warmth accelerates flower development.
The 3 to 5 centimeters long male cones are colored purple until pollination and are in the lower crown area. The up to 1.8 centimeters long female cones are red until pollination and then turn yellowish green. At the end of the first year, the female cones are around 2.5 centimeters long. The fertilization takes place about 14 months after pollination. The cones are initially green and turn reddish-brown when they ripen in September to November of the 2nd year. The cones are oval-cylindrical and relatively narrow with a length of 20 to 45 centimeters. After the seeds are released, they fall off and a few basal cone scales usually remain on the tree.
The relatively large, light-colored seeds have dark spots, are furrowed and. about 1.2 inches long. The striped wing is about 3.8 centimeters long and has a crooked upper end. The thousand grain weight is around 92.5 grams. It spreads via the wind ( anemochory ).
The number of chromosomes is 2n = 24.
Distribution and location
The natural distribution area extends largely over the plains of the Atlantic and Gulf coast. It ranges from southeast Virginia to eastern Texas . To the south, it extends to the southern part of central Florida . The distribution area extends up to 200 kilometers inland. Exceptions are the Piedmont region and the Appalachian foothills in northern Alabama and Georgia .
The swamp pine colonizes altitudes from 0 to 600 meters. It thrives in warm and humid temperate climates . The extreme temperatures in the distribution area are between 38 ° C and −18 ° C. The annual precipitation is between 1,090 and 1,750 mm and there are often short dry periods. This species is often found on well-drained, flat sands with a low humus content, but also on sands with varying degrees of moisture and sandy clays, which become wet with high rainfall and are correspondingly poor in oxygen. The soil pH is between 3.5 and 6.5.
In dry locations, the swamp pine forms mixed stands with the fork oak ( Quercus laevis ), the black oak ( Quercus marilandica ), the Virginia oak ( Quercus virginiana ), with Quercus incana and with Quercus stellata . Mixed stands with the flowering dogwood ( Cornus florida ), the American persimmon ( Diospyros virginiana ), the American sweetgum ( Liquidambar styraciflua ), the black tupelo tree ( Nyssa sylvestris ), the sickle-leaved oak ( Quercus falcata ), with Quercus laurifolia , with Quercus nigra and with the sassafras tree ( Sassafras albidum ) are formed in moist locations. The inkberry holly ( Ilex glabra ), Ilex vomitoria , Myrica cerifera , the winged sumac ( Rhus copallina ) and the saw palmetto ( Serenoa repens ) form the shrub layer in such locations.
The swamp pine is an economically important tree species in the southern states, but is less intensively cultivated and cultivated than other southern pine species. The resin-rich wood is used to make plywood, cellulose and wood pellets. It is used as beams, posts, sleepers and pillars in the construction of bridges, factories and warehouses. It is used as a veneer in interior construction . The resin was used to manufacture paints, varnishes, linoleum , paper and soaps, but is becoming less and less important due to the advent of synthetic materials. The long needles used to be used to make wickerwork, especially baskets and bowls.
Due to the grass stage of the seedlings, the swamp pine was less intensively cultivated than other pines of the North American south. Trees from different origins show differences in height growth, the height of the branches, root morphology, disease resistance and frost hardiness. There are greater differences between individuals than between different origins. Coastal origins grow faster than inland origins.
The almost white to yellowish, occasionally orange-white to light yellow colored sapwood stands out from the yellow to orange to red and light brown heartwood . The formation of the heartwood only begins in 20-year-old trees. Fast-growing, free-standing trees have a small core, while slow-growing and dense trees have a thick core. The annual rings are easy to see due to the dark latewood . Characteristic for the wood of the swamp pine is the intense resin odor, the medium to high impact resistance, the relatively strong shrinkage , but stability after drying and the poor adhesion of paints. It can only be worked on moderately well, is screw and nail proof and is quite durable even in damp locations. The grain is straight but irregular. The abbreviation as commercial timber according to EN 13556 is PNPL.
|Density (r 0 )||0.54||g / cm³|
Diseases and pests
Diseases generally do not pose a major threat to swamp pine. The fungus Mycosphaerella dearnessii extends the grass stage of the seedlings and leads to their needling. Seedlings grown under an umbrella are less susceptible. After the grass stage is over, susceptibility also decreases. The rust fungus Cronartium strobilinum attacks the female flower cones during withering and prevents the development of fertile cones. These pins are often used by Zünslern the genus Dioryctria used to develop that damage then even healthy cones. Fusarium moniliforme penetrates through wounds and releases resin pockets on shoots. Infestation with the root sponge ( Heterobasidion annosum ), various Coleosporium species and with Cronartium quercuum occurs relatively rarely in comparison to the above-mentioned harmful fungi and causes only minor damage.
On fresh hitting surfaces, the rejuvenation can be attacked by the two weevils Hylobius pales and Pachylobius picivorus . The bark beetle Dendroctonus frontalis attacks the middle and upper trunk parts while Dendroctonus terebrans attacks the lower trunk parts and kills bark parts. The whole tree rarely dies. The borer Dioryctria abietella feeds on flowers, buds and shoots and mines the cones so that they cannot form seeds. The curler Cydia ingens is a cone and seed pest and occurs mainly in seed plantations. Various species of the genera Leptoglossus and Tetrya also appear as cone and seed pests .
The first publication of Pinus palustris followed in 1768 by Philip Miller in his work "Gardener's Dictionary", eighth edition, number 14. Synonyms for Pinus palustris Mill. Are Pinus australis Michx. f. and Pinus longifolia Salisb.
Where the range of the swamp pine ( Pinus palustris ) overlaps with that of the frankincense pine ( Pinus taeda ), the naturally occurring hybrid Pinus × sondereggeri H.H.Chapm comes. ex Sudw. in front. This hybrid does not go through a grass stage and can therefore be easily distinguished from the swamp pine in the seedbed. In some areas, this hybrid accounts for up to 30% of the population. Crossing attempts were successful with Pinus echinata and Pinus elliottii .
- Schütt, Weisgerber, Schuck, Lang, Stimm, Roloff: Lexicon of Conifers . Nikol, Hamburg 2004, ISBN 3-933203-80-5 , p. 463-470 .
- Data sheet Pinus palustris at The Gymnosperm Database . (engl.)
- Pinus palustris at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- Pinus palustris at Tropicos.org. Missouri Botanical Garden, St. Louis, Retrieved April 21, 2019.