Pinus sylvestris, theScots pine (UK),Scotch pine (US),Baltic pine,[2] orEuropean red pine[3] is aspecies oftree in the pine familyPinaceae that isnative toEurasia. It can readily be identified by its combination of fairly short, blue-green leaves and orange-red bark.
Pinus sylvestris is anevergreenconiferous tree growing up to 35 metres (115 feet) in height[4] and 1 m (3 ft 3 in) in trunk diameter when mature,[5] exceptionally over 45 m (148 ft) tall and 1.7 m (5+1⁄2 ft) in trunk diameter on very productive sites. The tallest on record is a tree over 210 years old growing inEstonia which stands at 46.6 m (153 ft).[6] The lifespan is normally 150–300 years, with the oldest recorded specimens inLapland, NorthernFinland over 760 years.[7][8][9][10]
Thebark is thick, flaky and orange-red when young to scaly and gray-brown in maturity, sometimes retaining the former on the upper portion.[5][9][8] The habit of the mature tree is distinctive due to its long, bare and straight trunk topped by a rounded or flat-topped mass of foliage.[7][8][9][10]
The shoots are light brown, with a spirally arranged scale-like pattern. On mature trees theleaves ('needles') are a glaucous blue-green, often darker green to dark yellow-green in winter, 2.5–5 centimetres (1–2 inches) long and1–2 millimetres (1⁄32–3⁄32 in) broad, produced infascicles of two with a persistent gray5–10 mm (1⁄4–3⁄8 in) basal sheath. On vigorous young trees the leaves can be twice as long, and occasionally occur in fascicles of three or four on the tips of strong shoots. Leaf persistence varies from two to four years in warmer climates, and up to nine years in subarctic regions. Seedlings up to one year old bear juvenile leaves; these are single (not in pairs),2–3 cm (3⁄4–1+1⁄4 in) long, flattened, with a serrated margin.[7][9][10]
Mature open cones and seedsRoots of an old pine inYstad, Sweden
Theseed cones are red at pollination, then pale brown, globose and4–8 mm (5⁄32–5⁄16 in) in diameter in their first year, expanding to full size in their second year, pointed ovoid-conic, green, then gray-green to yellow-brown at maturity,3–7.5 cm (1+1⁄8–3 in) long. The cone scales have a flat to pyramidalapophysis (the external part of the cone scale), with a small prickle on theumbo (central boss or protuberance). Theseeds are blackish,3–5 mm (1⁄8–3⁄16 in) in length with a pale brown12–20 mm (1⁄2–13⁄16 in) wing and are released when the cones open in spring 22–24 months after pollination. The pollen cones are yellow, occasionally pink,8–12 mm (5⁄16–15⁄32 in) long;pollen release is in mid to late spring.[7][9]
Over 100Pinus sylvestrisvarieties have been described in thebotanical literature, but only three or four are now accepted.[11] They differ only minimally in morphology, but with more pronounced differences in genetic analysis andresin composition. Populations in westernmost Scotland are genetically distinct from those in the rest of Scotland and northern Europe, but not sufficiently to have been distinguished as separate botanical varieties. Trees in the far north of the range were formerly sometimes treated as var.lapponica, but the differences areclinal and it is not genetically distinct.[7][8][12][13][14][15][16][17][18][19][excessive citations]
Image
Varieties
Description
Distribution
Pinus sylvestris var.sylvestris L., 1753
Described above.
The bulk of the range, from Scotland and Spain to central Siberia.
Pinus sylvestris var.hamataSteven
Foliage more consistently glaucous all year, not becoming duller in winter; cones more frequently with a pyramidal apophysis.
The Balkans, northern Turkey, Crimea, and the Caucasus.
Pinus sylvestris var.mongolicaLitv.
Foliage duller green, shoots gray-green; leaves occasionally up to 12 cm long.
Mongolia and adjoining parts of southern Siberia and northwestern China.
Pinus sylvestris var.nevadensisD.H.Christ.
(not considered distinct from var.sylvestris by all authors) Kalenicz. Ex Kom. Cones often with thicker scales, but doubtfully distinguishable on morphology.
The Sierra Nevada in southern Spain and possibly other Spanish populations
Pinus sylvestris var.cretaceaKalenicz. ex Kom.
From border regions between Russia and Ukraine.[20]
Pinus sylvestris is the only pine native to northern Europe,[22][23] ranging fromWestern Europe to EasternSiberia, south to theCaucasus Mountains andAnatolia, and north to well inside theArctic Circle inFennoscandia. In the north of its range, it occurs from sea level to 1,000 m (3,300 ft), while in the south of its range it is a mountain tree, growing at 1,200–2,600 m (3,900–8,500 ft) altitude.[7][8][9][12] Its distribution intersects withT. piniperda's habitat, making the beetle a primary pest of the tree.
The species is mainly found on poorer, sandy soils, rocky outcrops, peat bogs or close to the forest limit. On fertile sites, the pine is out-competed by other tree species, usuallyspruce orbroad-leaved trees.[24]
Scattered survivors (two recently dead) of extensive deforestation at Glen Quoich, Scotland
The tree spread across Britain and Ireland after theLast Glacial Maximum. Pollen records show that pine was present locally in southern England by 9,000 years ago having entered from northeast France and that it had spread as far north as the Lake District and North Pennines 500 years later.[citation needed]
It was present in Ireland over 8,800 years ago but absent from Wales at that time which suggests that the pine in Ireland had a separate Iberian origin or contained surviving populations, although evidence towards its survival is lacking.[15] Pine expanded into Scotland between 8,000 and 8,500 years ago either from an independent refuge, from Scandinavia (viaDoggerland) or from Ireland. As the climate warmed it became extinct from most of Britain and Ireland around 5,500 years ago except in Scotland,Kielder in England andThe Burren inCounty Clare, Ireland.[citation needed]
The Irish and western Scottish populations went through a massive decline around 4,000 years ago which ultimately led to the practical extinction of the Irish population between 2,000 and 1,000 years ago. It was replaced by large areas of blanket bog in western Scotland and Ireland though the reasons for its decline and extinction inEngland are not clear, but it may have been influenced by human activities.[25]
In Britain it now occurs naturally only in Scotland. Historical and archaeological records indicate that it also occurred in Wales and England until about 300–400 years ago, becoming extinct there due toover-exploitation and grazing; it has been re-introduced in these countries. Similar historical extinction and re-introduction applies to Ireland, Denmark and the Netherlands.[9][12][10][26] Whether it truly became extinct in England is unknown. It has been speculated that it may have survived wild long enough for trees used in cultivation in England to derive from native (rather than imported) sources.[27]Shakespeare (inRichard II) was familiar with the species in the 1590s, as wasEvelyn in the early 1660s (Sylva), both around the time when the pine was thought to become extinct in England, but when landowners were also beginning ornamental and forestry planting.[27]
The pine formed much of theCaledonian Forest, which once covered much of theScottish Highlands. Overcutting fortimber demand, fire, overgrazing by sheep and deer, and even deliberate clearance to deter wolves have all been factors in the decline of this once great pine and birch forest. Only comparatively small areas – 17,000 hectares (42,000 acres), only just over 1% of the estimated original 1,500,000 ha (3,700,000 acres)[28] – of this ancient forest remain, the main surviving remnants being atAbernethy Forest,Glen Affric,Rothiemurchus Forest, and the Black Wood ofRannoch. Plans are currently in progress to restore at least some areas and work has started at key sites.[9][10]
In 2020, black spot needle blight was found on hundreds ofPinus sylvestris var.mongolica trees in four forest farms in northeastern China. It first appeared on the upper part of the needles, and then the needles became withered and gradually showed light black spots, although they still remained green. As the fungal disease progressed, the needles eventually died and turned gray with many dark black spots. The fungus was identified asHeterotruncatella spartii (within the familySporocadaceae) based on morphology and molecular methods.[29]
Pinus sylvestris is an important tree inforestry. The wood is used forpulp and sawntimber products. A seedling stand can be created by planting, sowing, or natural regeneration. Commercialplantation rotations vary between 50 and 120 years, with longer rotations in northeastern areas where growth is slower.[citation needed]
In Scandinavian countries, the pine was used for makingtar in the preindustrial age. Some active tar producers still exist, but that industry has almost ceased.[10][13] The pine has also been used as a source ofrosin andturpentine.[citation needed]
Thewood is pale brown to red-brown, and used for general construction work. It has a drydensity around 470 kg/m3 (varying with growth conditions), anopen porosity of 60%, afibre saturation point of 0.25 kg/kg, and a saturationmoisture content of 1.60 kg/kg.[13] The pine fibres are used to make the textile known asvegetable flannel,[30] which has ahemp-like appearance, but with a tighter, softer texture.[31]
The pine has also been widely planted in New Zealand and much of the colder regions of North America; it was one of the first trees introduced to North America, in about 1600.[32] It is listed as aninvasive species in some areas there, includingOntario,[33]Michigan.[34] It has been widely used in the United States for theChristmas tree trade, and was one of the most popular Christmas trees from the 1950s through the 1980s. It remains popular for that usage, though it has been eclipsed in popularity, by such species asFraser fir,Douglas-fir, and others. Despite its invasiveness in parts of eastern North America, the pine does not often grow well there, partly due to climate and soil differences between its native habitat and that of North America, and partly due to damage by pests and diseases; the tree often grows in a twisted, haphazard manner if not tended to (as they are in the Christmas tree trade).[8][22] The pines may be killed by thepine wood nematode, which causes pinewilt disease. The nematode most often attacks trees that are at least ten years old and often kills trees it infects within a few weeks.[35]
Previously, the pine was grown in and used extensively by the coal mining regions of Flanders, Belgium. It was used to fortify tunnels, primarily because it would make a cracking sound when in need of replacement. Large patches of forest, mostly containing the species, are still scattered over the countryside.[citation needed]
Genes of Scots Pine that are expressed in thehaploid stage of the life cycle appear to be subject to strongerpurifying selection than genes expressed only in the diploid stage.[44] The concept that those genes of an organism that are expressed in the haploid stage are subject to more efficient natural selection than those genes expressed exclusively in the diploid stage is referred to as the "masking theory".[44] This theory implies that purifying selection is more efficient in the haploid stage of the life cycle where fitness effects are more evidently expressed than in the diploid stage of the life cycle.[citation needed]
^Oidermaa, J.-J., ed. (9 February 2016)."Eesti kõrgeim mänd osutus hiiglaseks ka ülejäänud maailmas" [Estonia's tallest pine turned out to be a giant in the rest of the world as well].ERR Novaator (in Estonian). Tallinn: Eesti Rahvusringhääling. Retrieved9 February 2016.
^abcMirov, N. T. (1967).The Genus Pinus. New York: Ronald Press Company.OCLC712344.
^abcPravdin, L. F. (1969) [1964].Scots Pine: Variation, Intraspecific Taxonomy, and Selection. Jerusalem: Israel Program for Scientific Translations.OCLC121486.
^Szmidt, A. E.; Wang, X.-R. (1993). "Molecular systematics and genetic differentiation ofPinus sylvestris (L.) andP. densiflora (Sieb. et Zucc.)".Theoretical and Applied Genetics.86 (2–3):159–165.doi:10.1007/BF00222074.PMID24193455.S2CID10888339.
^Prus-Glowacki, W.; Stephan, B. R. (1994). "Genetic variation ofPinus sylvestris from Spain in Relation to Other European Populations".Silvae Genetica.43 (1):7–14.
^Goncharenko, G. G.; Silin, A. E.; Padutov, V. E. (1995). "Intra- and interspecific genetic differentiation in closely related pines fromPinus subsectionSylvestres (Pinaceae) in the former Soviet Union".Plant Systematics and Evolution.194 (1/2):39–54.Bibcode:1995PSyEv.194...39G.doi:10.1007/BF00983215.JSTOR23642988.S2CID12560701.
^abSullivan, J. (1993)."Pinus sylvestris".Fire Effects Information System. Fire Sciences Laboratory, Rocky Mountain Research Station, United States Department of Agriculture. Retrieved20 May 2023.
^Mátyás, C.; Ackzell, L.; Samuel, C. J. A. (2004).Scots pine –Pinus sylvestris(PDF). EUFORGEN Technical Guidelines for Genetic Conservation and Use. Rome: International Plant Genetic Resources Institute. p. 6.ISBN978-92-9043-661-4. Archived fromthe original(PDF) on 19 January 2017. Retrieved20 May 2023.
^Carlisle, A.; Brown, A. H. F. (1968). "Biological Flora of the British Isles: Pinus sylvestris L.".Journal of Ecology.56 (1):269–307.doi:10.2307/2258078.JSTOR2258078.
^Gleason, M.; Linit, M.; Zriba, N.; Donald, P.; Tisserat, N.; Giesler, L. (2000). Edwards, E. (ed.).Pine Wilt: A Fatal Disease of Exotic Pines in the Midwest(PDF). Sustainable Urban Landscapes. Iowa State University. SUL 9. Archived from the original on 15 May 2012. Retrieved20 May 2023.{{cite book}}: CS1 maint: bot: original URL status unknown (link)
^Rick Steves Scotland (second edition) By Rick Steves
^ The Pliocene flora of Frankfurt am Main, Germany: taxonomy, palaeoenvironments and biogeographic affinities by Zlatko Kvaček, Vasilis Teodoridis & Thomas Denk – Palaeobiodiversity and Palaeoenvironments, pages 647–703 (2020) – Springer Link –https://doi.org/10.1007/s12549-019-00391-6
^Oberpliocän-Flora aus den Baugruben des Klärbeckens bei Niederrad und Schleuse bei Höchst a M. T. Geyler F. Kinkelin. (Frankfort, 1887).
