White pine

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White pine
Specimens of the Weymouth Pine (Pinus strobus) in the Sherburne National Wildlife Refuge, Minnesota

Specimens of the Weymouth Pine ( Pinus strobus ) in the Sherburne National Wildlife Refuge , Minnesota

Systematics
Class : Coniferopsida
Order : Conifers (Coniferales)
Family : Pine family (Pinaceae)
Subfamily : Pinoideae
Genre : Pine ( Pinus )
Type : White pine
Scientific name
Pinus strobus
L.

The strobe ( Pinus strobus ), also Weymouth pine , white pine , or white pine called, is a plant from the genus of pine trees ( Pinus ) within the family of the Pinaceae (Pinaceae). It is the largest conifer in eastern North America , with specimens up to 500 years old. It is the official state tree of the US - states of Maine and Michigan .

The eponym does not refer to the English explorer and writer George Weymouth , who brought it to Europe in 1605 , but to Thomas Thynne, 1st Viscount Weymouth , who finally established it as a forest tree in England in the 18th century .

description

illustration
Strobes on Katherine Lake, Ottawa National Forest , Michigan
Stands of older trees in the Five Ponds Wilderness Area in New York , USA

Appearance

The Weymouth pine is an evergreen tree with heights between 25 and 35 meters, but which can also reach a height of 67 meters. The chest height diameter reaches values ​​of 1 to 3 meters. It can live up to 450 years. The columnar trunks grow straight and have strong branches. The branches, usually in groups of five in irregular whorls , are wide and extend almost at right angles from the trunk. At the ends they often straighten up and are needled in tufts. Young branches are very thin. Free-standing trees form a symmetrical, conical crown , while trees in the stand have a narrow crown and a long, knot-free trunk. Old trees that grow in the stand have a broad and irregular crown.

Root system

The main root system consists of a tap root and usually three to five far-reaching side roots, which penetrate to medium depths. The tap roots of old trees are usually badly damaged, which is why they are often thrown by the wind. On shallow and poorly drained soils, the Weymouth pine is a shallow root , while sinker roots grow downward from the side roots on deep soils. Small lateral roots are formed directly on the root neck.

The Weymouth pine forms ectomycorrhizae . Among the most common Mykorrhizapartnern include the fly agaric ( Amanita muscaria ), the chanterelle ( Cantharellus cibarius ), Russula lepida , Scleroderma vulgare , the Suillus Placidus ( Suillus placidus ) and the Crimson xerocomus ( Xerocomus rubellus ) and various types of Hohlfußröhrlinge ( Boletinus ), the clitocybe ( Clitocybe ) and the Milchlinge ( Lactarius ).

bark

Young trees have a thin and smooth bark that is dark green and often a little reddish tint. Old trees have cracked bark that is 2.5 to 5 centimeters thick. This is gray-brown in color and divided into wide scales, which are separated by shallow cracks. The young twigs have a green and downy hairy bark , which later becomes bare and orange in color. The bark of older twigs has a rough surface due to the permanent short shoot scars.

Wood

The cream-colored to straw-yellow heartwood is surrounded by an almost white sapwood . There are smooth transitions between early and late wood . Especially in the late wood, the resin canals are clearly visible, which stand individually or in groups of two or three. With a kiln density of 0.38 g / cm³, the soft straw wood is relatively light, but strong. It is screw-tight, easy to work on, impregnate and dry, but is not very durable. Even the heartwood has to be impregnated when it is installed in areas at risk of rot. The abbreviation as commercial timber according to EN 13556 is PNST.

Buds and needles

The sharply pointed, ovoid-cylindrical winter buds are between 0.4 and 1 centimeter long and have thin, reddish-brown colored bud scales that are somewhat resinified.

The blue to dark green needles are between 6 and 12 centimeters long and 0.7 to 1 millimeter wide. They stand in groups of five on the short shoots in 1 to 1.5 centimeters long, light orange-brown needle sheaths that fall off in August of the first year. The needles are straight, slightly twisted, soft and flexible. They are triangular in cross-section and their edges are finely sawn. Only the adaxial sides have narrow, white stomata bands . Usually two, more rarely one or three resin channels are formed. The needles stay on the tree for two to three years before they turn brown and fall off in autumn.

Flowers, cones and seeds

The strobe is single-sexed ( monoecious ) and becomes manable at the age of 5 to 10 , whereby male cones are not formed before the 9th year. The flowering period extends from May to June. The light brown to brown male cones are oval and are 0.8 to 1 centimeter long. You can find them standing upright on this year's shoots in the lower crown area. The up to 1.2 centimeters long female cones are pink to purple in color. They grow in groups of two to four mostly in the upper crown area at the tip of older shoots. In contrast to the female cones, the male ones are not produced every year. Pollination takes place in mid-June. Occasionally, self-fertilization occurs.

The cones are colored green after pollination and ripen in the second year. When ripe they are colored brown, rarely only 5, usually 8 to 20 and sometimes up to 25 centimeters long with a diameter of around 2.5 centimeters when closed and 4 to 8 centimeters when open. They are cylindrical in shape, narrow, and slightly curved. They can be found hanging on stems up to 2 centimeters long, individually or in groups on two-year-old twigs in the upper crown area. Younger cones are often resinified. The 40 to 100 relatively large cone scales are thin, woody, egg-shaped and flexible. The apophysis is dull and pale brown to gray-brown and more or less rhombic in outline on central scales and merges into a blunt, terminal umbo . Two seeds develop per cone scale. The ripe seeds are released at the beginning of August of the second year, the empty cones fall from the tree in winter.

The flattened, broadly obovate to almost triangular, rarely from 5, mostly 7 to 8 and sometimes up to 9 millimeters long seeds are reddish-brown to gray and black spotted and have a 20 to 28 millimeter long, pale brown wing, which is only with itself holds two small, lateral appendages on the seed body. The thousand grain weight is between 8.6 and 22.7 grams.

Most of the spread is caused by the wind ( anemochory ). The Weymouth pine mainly reproduces generatively, but it is also able to form subsidence .

Chromosome number

The number of chromosomes is 2n = 24.

Distribution and location

Distribution areas of Pinus strobus var. Strobus ( green ) and Pinus strobus var. Chiapensis ( red )

The natural range extends from Canada and the United States to southern Mexico and Guatemala, with a gap of 2,400 kilometers between the populations in North America and those in Central America, which includes the two varieties Pinus strobus var. Strobus and Pinus strobus var. chiapensis from each other.

In the northern part of the range, the species is mostly found on low hills and in the Appalachian Mountains up to an altitude of 1200 meters. Humid river plains, moors, dry and sandy plains, steep and rocky slopes and rocky knolls are populated. Fresh sand and loam as well as gravel that are well drained are ideal. Clays and waterlogged soils are less common. It grows there in societies of the Pinetea strobi class. As a pioneer, the Weymouth pine colonized burned areas, abandoned fields, meadows and windthrow areas, but is often displaced by deciduous trees in locations of medium quality. However, due to its unpretentious nature, it proves to be superior on low-quality locations. The pH of the populated soils is between 4.7 and 7.0. The annual rainfall is 510 to 2030 mm depending on the location, about half of which falls between April and September. Winters are cold and rich in snow.

The distribution area of ​​the variety chiapensis is in humid mountain areas with frequent fog at altitudes of 800 to 2000 meters. The amount of precipitation can reach values ​​of up to 3000 millimeters. Frost does not occur. Both varieties grow in mixed forests together with other coniferous or deciduous tree species, with several deciduous tree species, for example the American sweetgum tree ( Liquidambar styraciflua ) or the late blooming bird cherry ( Prunus serotina ), with similarly wide distribution areas in the Appalachian Mountains as well as in Mexico and Guatemala occurrence.

In 1999 the strobe grew to 0.26% of the Bavarian forest area and is the third most common foreign tree after Douglas fir and Japanese larch. Most of the trees were planted around 1900; After 1925 this hardly happened anymore because of the spread of the blister rust ( Cronartium ribicola ).
The strobe produces a higher yield than the pine and the wood fetch slightly higher prices. It has low nutrient requirements, is superior to pine on red sandstone and chalk and colonizes extreme locations such as sand, gravel, block and bog soils. It is frost and late frost hardy and little susceptible to wet snow. The best growing conditions are given on fresh, moist and semi-moist soils.

Hazard and protection

In the Red List of the IUCN is Pinus strobus classified as endangered ( "Least Concern"). The species has a very large distribution area in North America and the strobus variety spreads strongly in many areas. The large stocks, which were heavily used by the European settlers, were exhausted by the end of the 19th century. Fully grown trees are rare, but the species is not endangered by the strong growth. There are also many stocks in protected areas. Pinus strobus var. Chiapensis , however, is listed as endangered. The variety also has a large distribution area ("extent of occurrence"), but the populations are mostly small (5 to 20 hectares) and isolated. The largest stands are in Chiapas and Oaxaca, the largest of them at El Rincon in Oaxaca with around 50,000 mature trees in an area of ​​1,500 hectares. The actual overgrown area ("area of ​​occupancy") is estimated to be around 400 square kilometers, and the population continues to decline. In the past, the stocks were overexploited because the wood was used for shipping. Although the quality of the wood is good and the trees are used locally for logging, the main threats are deforestation for maize or coffee growing or the establishment of pastures for cattle. Another danger is the intrusion of alien species such as the horsetail casuarina ( Casuarina equisetifolia ) or the Mexican cypress ( Cupressus lusitanica ).

The Federal Agency for Nature Conservation estimates Pinus strobus as invasive species, and it has the management list of invasive species blacklist set because they can displace native species.

Systematics

The Weymouth pine is assigned to the subgenus Strobus , the section Quinquefoliae and the subsection Strobus within the genus of the pines ( Pinus ) . The first description as Pinus strobus , which is valid today, was made in 1753 by the Swedish naturalist Carl von Linné . There are two varieties:

  • Pinus strobus var. Strobus (Syn .: Pinus nivea Booth ex Carrière , Pinus strobus subsp. Cumberlandensis Silba ): The needles are on average 8 centimeters long. The seed cones reach a length of rarely 8, mostly 10 to 18 and sometimes up to 20 centimeters, the stem is up to 3 centimeters long. An average of 70 seed scales are formed, the sterile scales at the base are bent back. The range of the variety is in the east of North America. The strobus variety can be found in the forest areas around the Great Lakes and the St. Lawrence River . The northern limit of distribution extends from the boreal coniferous forests of Newfoundland over the Lake Superior to southeastern Manitoba . The western border runs through Wisconsin , southeast Minnesota , northeast Iowa, and Illinois . From these states the southern border runs back to the Atlantic coast of New England , but extends along the Appalachian Mountains to the deciduous forest regions of north-west South Carolina and north Georgia .
  • Pinus strobus var. Chiapensis Martínez (Syn .: Pinus chiapensis (Martínez) Andresen , Pinus strobus subsp. Chiapensis (Martínez) AEMurray ): The needles are on average 10 centimeters long. The cones have a very variable length between 6 and 25 centimeters, the stem is up to 4.5 centimeters long. An average of 90 seed scales are formed, the scales near the base are not bent back. The variety was first described in 1940 by Maximino Martínez as a variety of Pinus strobus . John William Andresen named the taxon as a separate species Pinus chiapensis (Martínez) Andresen , which is supported by morphometric studies. However, most authors consider the differences too small and stick with the classification as a variety. The distribution area of ​​the variety chiapensis is in Mexico in Guerrero , in the east of Puebla , in Veracruz , in Oaxaca and Chiapas and in Guatemala in the Departamento Quiché and in the Departamento Huehuetenango . The two populations were probably still connected during the Ice Age, when many tree species were displaced south by the advance of the glaciers.

Hybrids

The Weymouth pine forms hybrids with most of the other members of the Strobus subsection , exceptions are the sugar pine ( Pinus lambertiana ) and Armand's pine ( Pinus armandii ). The species forms luxuriant hybrids with the western Weymouth pine ( Pinus monticola ) and with the teardrop pine Pinus wallichiana . The cross with the lacrimal jaw is called Pinus × Schwerinii Fitschen .

use

Weymouth pine wood

Weymouth pine used to be the most important timber supplier in eastern North America. During the colonial period, the British government forbade the colonists from felling larger representatives of the species because they wanted the trees to be used exclusively for the British Navy as masts for ships. Due to the intensive use, there are hardly any old stocks today. Many farms, factories, and towns in the eastern and midwestern United States were built from the wood . It can be used in a variety of ways, both indoors and outdoors. Today, the majority of the wood is processed into sawn timber and plywood and used to make furniture, paper and toys. Other possible uses exist in the art joinery and as construction wood. The resilient and, after impregnation, durable wood is easy to nail, has straight fibers, does not warp very much and dries easily. Due to its homogeneous structure, it looks attractive and accepts colors well and was also used in shipbuilding in the past. (→ Main article: pine wood )

The Weymouth pine is widely planted, not only for logging, but also in urban areas and for reforestation of areas affected by coal mining. Americans and Canadians also often use representatives of the species as Christmas trees because they are easy to shape. Several cultivars are used in horticulture , among them especially dwarfed forms.

Cultivar 'Tortuosa' in the
Warsaw Botanical Garden
White pine with straw rust ( Cronartium ribicola )

Weymouth pines brought into the Black Forest are used in the craft of wood sculptors because of the wood to build cuckoo clocks .

Diseases and pests

In its natural range, the Weymouth pine is threatened by many fungal and animal pests, some of which were introduced. The risk of harmful fungi only increased when the species was cultivated for forestry in unsuitable locations. The entrained from Europe Strobenrost ( Cronartium ribicola ) is the most dangerous and most widespread fungus of White Pine. Both young and old trees are attacked, especially in regions with high humidity and on the edge of the Great Lakes. An infestation on the trunk can lead to the death of young trees. An infestation on the branches lowers the ornamental value and is especially dangerous for Christmas tree cultures. Stem rot is caused by the violet cartilage layer fungus ( Chondrostereum purpureum ) and the pine fire sponge ( Phellinus pini ). The Dark honey fungus ( Armillaria ostoyae ), the root sponge ( Heterobasidion annosum ) and the phaeolus schweinitzii ( Phaeolus schweinitzii ) call root rot out, addressed to but only minor damage.

The common pine weevil ( Pissodes pini ) has the greatest economic importance of the 277 pest insects found on the Weymouth pine. It causes trunk curvatures and loss of growth in the trees because it kills the top shoots and the tree erects the upper lateral shoots. Young trees can die in the event of an infestation. Serious damage is mainly caused in two to three-year stands and in Christmas tree cultures. The caterpillars of the pine shoot moth ( Rhyacionia buoliana ) hollow out the top shoots . The infected trees develop deformations but do not die. The weevil Hylobius pales feeds on the bark of trees that are up to five years old. There are frequent departures. Conophthorus coniperda occurs in the entire distribution area of ​​the Weymouth pine. It mainly attacks annual cones and is able to destroy the cone harvest for a whole year.

The Weymouth pine is sensitive to late frosts. Ice curtains and wet snow can break branches and break the trunk. The species is considered to be the most sensitive tree of all North American tree species. It is particularly sensitive to hydrogen fluoride . However, some authors classify it as only moderately susceptible to ozone and sulfur dioxide .

Forest fires often turn out to be a threat to the population, as they can still be lost after several years. Young trees in particular are particularly at risk of forest fires due to their thin bark.

symbolism

As a widespread species in eastern North America, the Weymouth pine was selected as the official symbol of the US states of Maine and Michigan , as well as the Canadian province of Ontario . Since September 2017 it has also been depicted as a symbol of the five tribes of the Iroquois Confederation in the coat of arms and in the flag of Montreal .

swell

literature

  • Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden / Boston 2010, ISBN 978-90-04-17718-5 , pp. 609, 762-764 .
  • James E. Eckenwalder: Conifers of the World. The Complete Reference . Timber Press, Portland, OR / London 2009, ISBN 978-0-88192-974-4 , pp. 476, 479-480 .
  • Peter Schütt, Horst Weisgerber, Hans J. Schuck, Ulla Lang, Bernd Stimm, Andreas Roloff: Lexicon of Conifers. Distribution - Description - Ecology - Use; the great encyclopedia . Nikol, Hamburg 2004, ISBN 3-933203-80-5 , p. 491-505 .
  • Robert Kral: Pinus. In: 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 , Pinus strobus , p. 379-380 (English, online ).
  • Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinus. In: 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 , Pinus strobus , p. 25 (English, online ).
  • Russell H. Burns: Silvics of North America . Volume 1: Conifers . In: Agriculture Handbook . United States Government Printing, Oxford 1991, ISBN 0-16-027145-2 ( online ).

Individual evidence

  1. ^ Manfred A. Fischer, Karl Oswald, Wolfgang Adler: Excursion flora for Austria, Liechtenstein and South Tyrol . 3rd, improved edition. Province of Upper Austria, Biology Center of the Upper Austrian State Museums, Linz 2008, ISBN 978-3-85474-187-9 , p. 252 .
  2. Eckehart J. Jäger, Klaus Werner (Ed.): Exkursionsflora von Deutschland . Founded by Werner Rothmaler. 10th edited edition. tape 4 : Vascular Plants: Critical Volume . Elsevier, Spektrum Akademischer Verlag, Munich / Heidelberg 2005, ISBN 3-8274-1496-2 .
  3. Schütt among others: Lexicon of the conifers. 2004, p. 499.
  4. ^ A b Robert Kral: Pinus strobus in Flora of North America , Volume 2
  5. Schütt among others: Lexicon of the conifers. 2004, p. 492.
  6. ^ Illustration by Aylmer Bourke Lambert (1761–1842) from A Description of the Genus Pinus. DOI: 10.5962 / bhl.title.44704 .
  7. a b c d e f Aljos Farjon: A Handbook of the World's Conifers. Volume 2, 2010, p. 762.
  8. a b c d Schütt among others: Lexicon of the conifers. 2004, p. 493.
  9. a b c Christopher J. Earle: Pinus strobus. In: The Gymnosperm Database. www.conifers.org, November 28, 2012, accessed on November 23, 2013 .
  10. Schütt among others: Lexicon of the conifers. 2004, p. 497.
  11. a b c Schütt among others: Lexicon of the conifers. 2004, p. 496.
  12. a b James E. Eckenwalder: Conifers of the World. 2009, p. 479.
  13. a b Burns: Pinus strobus. In: Silvics of North America. Retrieved November 23, 2013 .
  14. a b c Schütt among others: Lexicon of the conifers. 2004, p. 495.
  15. ^ Tropicos. [1]
  16. a b c Aljos Farjon: A Handbook of the World's Conifers. Volume 2, 2010, pp. 762-763.
  17. ^ Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . With the collaboration of Angelika Schwabe and Theo Müller. 8th, heavily revised and expanded edition. Eugen Ulmer, Stuttgart (Hohenheim) 2001, ISBN 3-8001-3131-5 , pp. 95 .
  18. Schütt among others: Lexicon of the conifers. 2004, pp. 498-499.
  19. a b c d e f Aljos Farjon: A Handbook of the World's Conifers. Volume 2, 2010, p. 763.
  20. a b c d e James E. Eckenwalder: Conifers of the World. 2009, p. 480.
  21. Foreign tree species: (Un) popular permanent guests. In: LWF-aktuell. Volume 20, 1999, pp. 6, 8, 12, 19 and 20 ( PDF file ).
  22. Pinus strobus in the endangered Red List species the IUCN 2013. Posted by: A. Farjon, 2011. Accessed November 23, 2013.
  23. Pinus strobus var. Chiapensis in the Red List of Threatened Species of the IUCN 2013. Posted by: P. Thomas, A. Farjon, 2011. Accessed November 23, 2013.
  24. Birgit Seitz, Stefan Nehring: Pinus strobus - Weymouth pine. In: Stefan Nehring, Ingo Kowarik, Wolfgang Rabitsch, Franz Essl (eds.): Nature conservation invasiveness assessments for alien vascular plants living in the wild in Germany (= BfN scripts. Volume 352). Federal Agency for Nature Conservation, Bonn-Bad Godesberg 2013, ISBN 978-3-89624-087-3 , pp. 150–151 (PDF file).
  25. Carl von Linné : Species Plantarum . tape 2 . Lars Salvius, Stockholm 1753, p. 1001 ( online ).
  26. a b Rafaël Govaerts (Ed.): Pinus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 26, 2019.
  27. Schütt among others: Lexicon of the conifers. 2004, pp. 492-493.
  28. Pinus strobus var. Chiapensis. In: The International Plant Name Index. Retrieved November 23, 2013 .
  29. Pinus chiapensis. In: The International Plant Name Index. Retrieved November 23, 2013 .
  30. ^ John Syring, Rafael F. del Castillo, Richard Cronn, Aaron Liston: Multiple Nuclear Loci Reveal the Distinctiveness of the Threatened, Neotropical Pinus Chiapensis . In: Systematic Botany . tape 32 , no. 4 , 2007, p. 703-717 ( online, pdf ). doi : 10.1043 / 06-64.1 (currently not available)
  31. ^ Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinus strobus. In: Flora of China. Volume 4, p. 25.
  32. ^ Aljos Farjon: A Handbook of the World's Conifers. Volume 2, 2010, p. 764.
  33. Schütt among others: Lexicon of the conifers. 2004, pp. 497-498.
  34. James E. Eckenwalder: Conifers of the World. 2009, p. 476.
  35. Schütt among others: Lexicon of the conifers. 2004, p. 502.
  36. Jochen Loebbert: Craftsmanship! How to build a cuckoo clock , SWR Fernsehen - Landesschau Baden-Württemberg from August 24, 2018 (YouTube from November 26, 2018)
  37. a b c Schütt among others: Lexicon of the conifers. 2004, pp. 500-501.
  38. Montreal adds Iroquois symbol to flag, strips British general of street name. CBC, September 13, 2017, accessed September 13, 2017 .

Web links

Commons : Weymouth pine ( Pinus strobus )  - Collection of images, videos and audio files