Pinus virginiana
| Pinus virginiana | ||||||||||||
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Pinus virginiana |
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| Pinus virginiana | ||||||||||||
| Mill. |
Pinus virginiana is a plant from the genus of pine trees ( Pinus ) within the family of the Pinaceae (Pinaceae). The natural range is in the eastern United States. It is often used as a Christmas tree .
description
Appearance
Pinus virginiana grows as an evergreen tree that usually reaches heights of 15 to 18 meters, rarely up to 25 meters. The trunk is straight, twisted or forked and reaches diameters of up to 50 centimeters at chest height . Or it grows like a bush. The trunk bark is thin and scaly, irregularly furrowed and gray-brown in the lower area of thick trunks, and reddish in higher areas of the trunk. The numerous branches are irregularly horizontal or erect and often form a dense, rounded or flat crown. The needled branches are thin and the leaf sheaths that have fallen off from pulvini are rough. Young shoots are glabrous, reddish brown, often overlaid with bluish tones ( glauk ) and later turn reddish brown to gray.
Buds and needles
The winter buds are relatively short and thick, with a length of 5 to 10 millimeters, ovate with a short pointed end and resinous or not resinous. The bud scales are red-brown and have a whitish edge.
The needles stand horizontally in twos in a permanent, basal, 4 to 10 millimeter long needle sheath and stay on the tree for three to four years. The light, dark or yellowish green needles are inelastic and often strongly twisted, 3 to 8 centimeters long and 1 to 1.5 millimeters wide, with a broad triangular cross-section. The edge of the needle is finely sawn, the end narrowly pointed. There are inconspicuous stomata lines on all needle sides . Two resin channels running in the middle are formed for each needle .
Cones and seeds
The pollen cones are ellipsoidal-cylindrical, 10 to 15 millimeters long, red-brown and yellow during flowering . The seed cones are single or in pairs. They are almost sitting or grow on a stalk that is up to 1 centimeter long. They are 3.5 to 7 inches long, slightly oblique to symmetrical, closed conical and open ovoid. The seed scales are elongated, woody and inelastic, matt red-brown with a distinct purple-red edge. The apophysis is significantly raised or somewhat thickened, keeled transversely and light brown. The umbo is pyramidal and reinforced with a solid, thin, 5 millimeter long, straight or bent back stinger . The seeds are obovate, 4 to 6 sometimes to 7 millimeters long, slightly flattened with an oblique tip, pale brown with dark spots. The seed wing is narrow and 16 to 20 millimeters long.
Chromosome number
The number of chromosomes is 2n = 24.
Growth and development
Pinus virginiana does not reproduce vegetatively in a natural way . The pollination is carried out depending on the temperatures from mid-March to late May as with all pine trees by the wind, fertilization occurs about 13 months later when the pins have reached their full size. The cones ripen from late September to early November. The seeds are released a short time later. The cones can then stay on the tree for up to 15 years. Some cones ripen every year, fattening years with a particularly large number of cones occur about every three years. The seedlings need direct sunlight and are drought-resistant compared to other pine species. Under favorable conditions, they can reach a height of 10 to 20 centimeters in the first year, after 10 years they can reach a height of 5 meters and after about 60 years they are fully grown. Cones begin to form after about 5 to 50 years.
Spread and endangerment
The natural range of Pinus virginiana is in the eastern United States and includes the states of New Jersey , Ohio , Pennsylvania , West Virginia , southern Indiana , Alabama , Delaware , Georgia , Kentucky , Maryland , North Carolina , South Carolina , Tennessee, and Virginia . There it grows in the Piedmont and on lower slopes of the Appalachian Mountains , from the coast in the north to higher altitudes of 650 meters inland in the south of the distribution area. It was naturalized in the Canadian provinces of Alberta , British Columbia and Ontario , and is used for forestry in the Chinese provinces of Jiangsu and Jiangxi .
In the Red List of the IUCN is Pinus virginiana risk than low ( "Lower Risk / near threatened") classified. However, it should be noted that a reassessment is pending.
ecology
climate
The climate in the natural range is mostly cool and humid with extensive snowfalls, especially in the north of the range. The mean annual amount of precipitation is between 890 and 1400 millimeters and is quite evenly distributed over the whole year. The greatest amount of precipitation falls in the southwest of the range. The mean summer temperature is between 21 and 24 ° C, the mean winter temperatures range from −4 to 4 ° C. The mean number of frost-free days is 225 days in the south and east and drops to 160 days in mountainous locations in the west and north of the distribution area. The distribution area is assigned to winter hardiness zone 6 with mean annual minimum temperatures between −23.2 and −17.8 ° C (−10 to 0 Fahrenheit ).
Soil condition
Pinus virginiana grows on a variety of different, mostly nutrient-poor soils that have formed from sediments, crystalline rock, sandstone, slate and, to a lesser extent, lime. The species grows best on clays, loams or sandy loams, it develops poorly on flat soils on slate and on very sandy soils. It only grows on well-drained to well-drained subsoil from acidic to neutral soils with pH values of 4.6 to 7.9.
Socialization
It is a pioneer species that is currently repopulating large areas of abandoned farmland (as of 2010). Under these conditions or in disturbed environmental conditions, Pinus virginiana usually grows in a bush shape, but can also form larger trees in undisturbed forest surroundings. In such forests it is of secondary importance and grows together with various oak species ( Quercus spp.) And sometimes other pine species such as Pinus echinata , the pitch pine ( Pinus rigida ) and the frankincense pine ( Pinus taeda ). In addition, depending on the location, other conifers such as the Canadian hemlock ( Tsuga canadensis ) and the occidental tree of life ( Thuja occidentalis ) can also be found. In the northeast of the distribution area, in the so-called Pine Barrens , various lichens , for example representatives of the genera Cladina and Cladonia and the bush oak ( Quercus ilicifolia ), form the only undergrowth.
Importance to the animal world
The seeds are an important food source for a large number of small mammals and birds, and in some areas it is also an important food source for white-tailed deer ( Odocoileus virginianus ). Older trees with stem rot are good nesting opportunities for woodpeckers.
Damage and influence of fire
Many factors can lead to the death of trees, common causes are fire, wind breakage, stem rot caused by the pine fire sponge ( Phellinus pini ) and tree cancer caused by Fusarium moniliforme . Insects such as the bark beetle Dendroctonus frontalis and members of the genus Neodiprion from the family of the bushhorn sawfly (Diprionidae) pose additional dangers . The weevil Hylobius pales attacks seedlings. Pinus virginiana is sensitive to air pollutants such as ozone , sulfur oxides and nitrogen oxides .
Although forest fires can destroy many specimens, the presence of the species (like all other Pinus species in the ecosystem) is dependent on forest fires, which create open, low-competition spaces. If there are no forest fires, the pines will be displaced by deciduous tree species over time. Fires, which also affect the soil's humus layer, are an important factor in establishing the building. Germination occurs mainly on exposed mineral soil.
Systematics and research history
The first publication of Pinus virginiana was in 1768 by Philip Miller in Gardeners Dictionary , Edition 8, number 9. The specific epithet virginiana is reminiscent of the English colony of Virginia , which extended over a large part of the eastern United States. Synonyms for Pinus virginiana Mill. Are Pinus inops Aiton , Pinus ruthenica Carrière and Pinus turbinata Bosc .
The species Pinus virginiana belongs to the sub-section Contortae from the section Trifoliae in the sub-genus Pinus within the genus Pinus . The sub-section Contortae consists of four closely related, two-needle, North American species, but attempts at crossing were only successful with the sand pine ( Pinus clausa ).
use
In forestry , Pinus virginiana is considered to be too bushy, but it can grow into a moderately large tree, especially if it is planted on abandoned farmland or coal mining. The wood from these areas, especially from the southeast of the distribution area, is used as timber or processed into pulp . Pinus virginiana is also an important Christmas tree that is grown and sold in large numbers. It is rarely used as an ornamental tree , but cultivated dwarf forms are planted in rock gardens .
The Cherokee used various parts of the Pinus virginiana plant for medicinal purposes, for example the bark was chewed to treat diarrhea , the needles were taken for fever. There were uses for colds, rheumatism , tuberculosis and hemorrhoids .
swell
literature
- Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 90-04-17718-3 , pp. 778-779 .
- Robert F. Powers, William W. Oliver: Virginia Pine In: Russell H. Burns: Silvics of North America . Volume 1 Conifers . United States Government Printing, 1991, ISBN 0-16-027145-2 ( online ).
- Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico . Volume 2: Pteridophytes and Gymnosperms . Oxford University Press, New York / Oxford a. a. 1993, ISBN 0-19-508242-7 (English).
- Wu Zheng-yi, Peter H. Raven (Ed.): Flora of China . Volume 4: Cycadaceae through Fagaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 1999, ISBN 0-915279-70-3 , pp. 21 (English).
- Helmut Genaust: Etymological dictionary of botanical plant names. 3rd, completely revised and expanded edition. Nikol, Hamburg 2005, ISBN 3-937872-16-7 , p. 487 (reprint from 1996).
Individual evidence
- ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 2, pp. 778-779.
- ↑ a b c d e f g h Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 779
- ↑ a b c Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinus virginiana , in Flora of China , Volume 4, p. 21.
- ^ A b Robert Kral: Pinus virginiana in Flora of North America , Volume 2.
- ↑ Pinus virginiana at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- ↑ a b c d e f g Christopher J. Earle: Pinus virginiana. In: The Gymnosperm Database. www.conifers.org, November 28, 2012, accessed April 10, 2013 (English).
- ^ A b Pinus virginiana in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved April 7, 2013.
- ↑ Pinus virginiana in the endangered Red List species the IUCN 2012. Posted by: Conifer Specialist Group, 1998. Accessed April 7, 2013.
- ^ A b Powers, Oliver: Virginia Pine In: Silvics of North America .
- ↑ Lawrence S. Barden, Frank W. Woods (1976): Effects of fire on Pine and Pine-harwood forests in the Southern Appalachians. Forest Science vol.22 no.4: 399-403.
- ↑ James M. Vose, Wayne T. Swank, Barton D. Clinton, Ronald L. Hendrick, Amy E. Major (1995): Using Fire to Restore Pine / Hardwood Ecosystems in the Southern Appalachians of North Carolina. In: Proceedings: First Conference on Fire Effects on Rare and Endangered Species and Habitats, Nov. 13-16, 1995: 149-154.
- ↑ a b Pinus virginiana at Tropicos.org. Missouri Botanical Garden, St. Louis, Retrieved April 18, 2019.
- ^ A b Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 778
Web links
- Pinus virginiana at Plants For A Future . Retrieved April 7, 2013.