Trees to 50 m tall; trunk to 1 m d.b.h.; bark gray-brown or gray, fissured longitudinally into irregularly oblong plates, inner bark red-brown; branchlets densely red-brown, occasionally yellow pubescent; winter buds reddish brown, oblong-ovoid, slightly resinous. Needles 5 per bundle, dark green, straight, almost triangular in cross section, 6-12 cm, stomatal lines 6-8 along each abaxial surface, blue-gray, vascular bundle 1, resin canals 3, median, base with sheath shed, margin serrulate. Seed cones solitary or several clustered near apex of 1st-year branchlets, erect, pedunculate (peduncle 1-1.5 cm), conical-ovoid or ovoid-oblong, 9-14 × 6-8 cm, indehiscent or slightly dehiscent at maturity, with seeds exposed but not shed. Seed scales reflexed at apex. Seeds triangular-obovoid, 1.2-1.6 cm, wingless.
The tree species Pinus koraiensis is commonly called Korean pine. It is native to eastern Asia: Korea, Manchuria, Mongolia, the Temperate rainforests of the Russian Far East, and central Japan. In the north of its range, it grows at moderate altitudes, typically 600 metres (2,000 ft) to 900 metres (3,000 ft), whereas further south, it is a mountain tree, growing at 2,000 metres (6,600 ft) to 2,600 metres (8,500 ft) altitude in Japan. It is a large tree, reaching a mature size of 40 metres (130 ft) to 50 metres (160 ft) height, and 1.5 metres (4.9 ft) to 2 metres (6.6 ft) trunk diameter.
It is a member of the white pine group, Pinus subgenus Strobus, and like all members of that group, the leaves ('needles') are in fascicles (bundles) of five, with a deciduous sheath. They are 7 centimetres (2.8 in) to 13 centimetres (5.1 in) long. Korean pine cones are 8 centimetres (3.1 in) to 17 centimetres (6.7 in) long, green or purple before maturity, ripening brown about 18 months after pollination. The 14 millimetres (0.55 in) to 18 millimetres (0.71 in) long seeds have only a vestigial wing and are dispersed by Spotted Nutcrackers.
Korean pine nuts
Korean pine differs from the closely related Siberian pine in having larger cones with reflexed scale tips, and longer needles.
The seeds are extensively harvested and sold as pine nuts, particularly in northeastern China; it is the most widely traded pine nut in international commerce. The nut oil contains 11.5% of the unusual fatty acid pinolenic acid (cis–5–cis–9–cis–12 octadecatrienoic acid).
Korean pine is a popular ornamental tree in parks and large gardens where the climate is cold, such as eastern Canada and the northeastern states of the USA, giving steady though not fast growth on a wide range of sites. It is tolerant of severe winter cold, hardy down to at about −50 °C (−58 °F).
Das, A. K. Studies on the growth pattern, primary productivity and nutrient dynamics of Khasi pine (Pinus kesiya Royal ex Gordan). Diss. Ph. D. thesis, North Eastern Hill University, Shillong, India, 1980.
In the Russian Far East this pine grows from 200 m to 600 m a.s.l., 500 m to 1,300 m a.s.l. in China, and in Japan it occurs to an altitude of 2,500 m. The climate has a summer monsoon character within proximity of the coast, but with a strong continental influence further inland. Temperature extremes range from +37 C to -45 C within its natural range. Pinus koraiensis grows in dry places on podzols among deciduous broad-leaved trees like oaks, poplars and birches, but on the Russian coast of the Sea of Japan it is codominant with Abies holophylla, forming groves of conifers in a more varied deciduous broad-leaved forest. In Japan it also occurs together with other pines. In Korea and NE China ('Manchuria') this pine has been heavily exploited, resulting in the disappearance of many magnificent pine forests.
Pinus koraiensis has a wide distribution in the Russian Far East, northeast China and North Korea. Smaller subpopulations also occur in South Korea and Japan. In the Russian Far East legal and illegal exploitation for its timber has resulted in a decline in its area of occupancy of up to 50% (CITES 2010). In China over-exploitation for its edible nuts and to a lesser extent, its timber is leading to forest degradation in some areas (Tang 2010). There is little species specific information about its status in North Korea although generalized reports into the state of the environment (UNEP 2003, Hayes 2009) and satellite based studies on deforestation in and around areas such as Changbaishan/ Baekdu-san Biosphere Reserves (Tang 2010) indicate that some decline is likely. In South Korea and Japan the small subpopulations are thought to be stable. Despite the continuing exploitation, this species' large distribution and (still) large overall population size means that it does not yet meet the requirements for any of the threatened categories or those for Near Threatened. This situation may change within the next decade should current trends continue.