Scots pine

''Pinus sylvestris'', the Scots pine (UK), Scotch pine (US) or Baltic pine, is a species of tree in the pine family Pinaceae that is native to Eurasia. It can readily be identified by its combination of fairly short, blue-green leaves and orange-red bark.

Description

''Pinus sylvestris'' is an evergreen coniferous tree growing up to in height and in trunk diameter when mature, exceptionally over tall and in trunk diameter on very productive sites. The tallest on record is a tree over 210 years old tree growing in Estonia which stands at . The lifespan is normally 150–300 years, with the oldest recorded specimens in Lapland, Northern Finland over 760 years.

The bark is thick, flaky and orange-red when young to scaly and gray-brown in maturity, sometimes retaining the former on the upper portion.Trees for Life
Species profile: Scots pine
/ref> 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.Farjon, A. (2005). ''Pines Drawings and Descriptions of the Genus Pinus'' 2nd ed. Brill .Steven, H. M., & Carlisle, A. (1959, facsimile reprint 1996). ''The Native Pinewoods of Scotland''. Castlepoint Press.

The shoots are light brown, with a spirally arranged scale-like pattern. On mature trees the leaves ('needles') are a glaucous blue-green, often darker green to dark yellow-green in winter, long and broad, produced in fascicles of two with a persistent gray 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), long, flattened, with a serrated margin.

The seed cones are red at pollination, then pale brown, globose and 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, long. The cone scales have a flat to pyramidal apophysis (the external part of the cone scale), with a small prickle on the umbo (central boss or protuberance). The seeds are blackish, in length with a pale brown wing and are released when the cones open in spring 22–24 months after pollination. The pollen cones are yellow, occasionally pink, long; pollen release is in mid to late spring.

Varieties

Over 100 ''Pinus sylvestris'' varieties have been described in the botanical literature, but only three or four are now accepted. They differ only minimally in morphology, but with more pronounced differences in genetic analysis and resin 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 are clinal and it is not genetically distinct.Mirov, N. T. (1967). ''The Genus Pinus''. Ronald Press.Pravdin, L. F. (1969). ''Scots Pine. Variation, intraspecific Taxonomy and Selection''. Israel Program for Scientific Translations (originally published 1964 in Russian).

Names

Before the 18th century, the species was more often known as Scots fir or Scotch fir. Another, less common name is European redwood.

The timber from it is also called red deal or yellow deal, the name "deal" being adopted from an archaic unit of volume used to measure wood.

Distribution and habitat

''Pinus sylvestris'' is the only pine native to northern Europe, ranging from Western Europe to Eastern Siberia, south to the Caucasus Mountains and Anatolia, and north to well inside the Arctic Circle in Fennoscandia. In the north of its range, it occurs from sea level to , while in the south of its range it is a mountain tree, growing at altitude.

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, usually spruce or broad-leaved trees.

Britain and Ireland

The tree spread across Britain and Ireland after the Last 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.

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. Pine expanded into Scotland between 8,000 and 8,500 years ago either from an independent refuge, from Scandinavia (via Doggerland) or from Ireland. As the climate warmed it became extinct from most of the Britain and Ireland around 5,500 years ago except in Scotland, Kielder in England and The Burren in County Clare, Ireland.

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 in England are not clear, but it may have been influenced by human activities.

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 to over-exploitation and grazing; it has been re-introduced in these countries. Similar historical extinction and re-introduction applies to Ireland, Denmark and the Netherlands.Carlisle, A., & Brown, A. H. F. (1968). Biological Flora of the British Isles: Pinus sylvestris L. ''J. Ecol''. 56: 269–307. 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.Edlin, H. L. (1970). ''Trees, Woods and Man'', 3rd ed. Collins: New Naturalist. Shakespeare (in ''Richard II'') was familiar with the species in the 1590s, as was Evelyn 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.

The pine formed much of the Caledonian Forest, which once covered much of the Scottish Highlands. Overcutting for timber 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, only just over 1% of the estimated original of this ancient forest remain, the main surviving remnants being at Abernethy Forest, Glen Affric, Rothiemurchus Forest, and the Black Wood of Rannoch. Plans are currently in progress to restore at least some areas and work has started at key sites.

Ecology

It forms either pure fo