== Major species and synonyms ==
* ''Pinus kesiya'' Royle ex Gordon, Loudon, Gard. Mag. 16: 8 (1840), synonyms: *''P. insularis'' Endl. (1847), *''P. khasya'' Royle ex Hook.f. (1888).
* ''Pinus merkusii'' Jungh. & de Vriese, Pl. Nov. Ind. Bat. Or.: 5, t. 2 (1845), synonyms: *''P. sumatrana'' Jungh. (1846), *''P. merkusiana'' Cooling & Gaussen (1970).
== Vernacular names ==
* ''P. kesiya'' : *Benguet pine, Khasya pine (En). *Pin à trois feuilles (Fr)*Philippines: saleng (general), tapulao (Zambales), bariat (Bontoc). *Burma (Myanmar): tinyu
*Laos: khoua, mai hing
*Thailand: son-sambai (central), chuang, kai-plueak-daeng (northern)
*Vietnam: thông ba lá, xà nu.
* ''P. merkusii'' : *merkus pine, Mindoro pine, Sumatran pine (En)
*Indonesia: tusam (general), damar batu, damar bunga (Aceh, Sumatra)
*Philippines: tapulau (Sambali, Tagalog)
''Pinus'' comprises slightly more than 100 species. Its evolutionary origin has been located in the early Jurassic or late Triassic period. The earliest fossil records are all from eastern Siberia. The present-day centres of diversity are located in Mexico, the eastern United States, and the mainland of eastern Asia. Only 2 species occur naturally in the Malesian region: ''P. kesiya'' (eastern India, Burma (Myanmar), Indo-China, southern China, northern Thailand and the Philippines (northern Luzon)); and ''P. merkusii'' (eastern Burma (Myanmar), Indo-China, southern China, northern Thailand, the Philippines (Mindoro, western Luzon), Sumatra (Aceh, Tapanuli region, Kerinci mountain)). Thus ''P. merkusii'' is the only ''Pinus'' occurring south of the Equator. ''P. kesiya'' is planted throughout the tropics, in South-East Asia in Thailand, the Philippines, Malaysia and Papua New Guinea whereas ''P. merkusii'' is mainly planted in South-East Asia.
== Uses ==
Pines are tapped worldwide for the resin the sapwood exudes when only the cambium or both cambium and sapwood are injured. "Gum rosin" and "gum turpentine" are produced from this so-called "crude resin" by steam distillation. Rosin and turpentine can also be obtained as a by-product of the sulphate or Kraft process in pulping pine wood ("tall oil rosin" and "sulphate turpentine") and by extracting from the stumps of pines long after they have been felled, which yields "wood rosin" and "wood turpentine". Rosin, a brittle, transparent, glossy, faintly aromatic solid, has a wide range of applications, such as in the manufacture of adhesives, paper-sizing agents, printing inks, solders and fluxes, various surface coatings, insulating materials for the electronic industry, synthetic rubber, chewing gums, soaps and detergents. Whereas the use of rosin for paper size is decreasing, it is increasing for the manufacture of printing inks. Turpentine, a clear liquid with a pungent odour and bitter taste, is used either as a solvent for paints and varnishes, or as a raw material for fractionation and value-added derivative manufacture of fragrances, flavours, vitamins, polyterpene resins and adhesives. Its use as a solvent has now largely been replaced by "white spirit" derived from petroleum. The biggest single turpentine derivative, synthetic "pine oil", is used in disinfectants, cleaning agents and other products with a "pine" odour. Other derivatives including isobornyl acetate, camphor, linalool, citral, citronellol, citronellal, and menthol are used either on their own or in the elaboration of other fragrance and flavour compounds. The resin of ''P. merkusii'' , known as "gondorukem" is one of the ingredients in the wax used for the manufacture of batik fabric.
Pine is a good general-purpose timber, although in woodworking and finishing aspects its resinous nature requires special attention. It is an excellent construction material. In the mining area of ''P. kesiya'' in northern Luzon, the Philippines, it is used as mine props. It is also used as piles, posts, Christmas trees, and as raw material for pulp and paper. Pine trees also make good fuel, both for cooking and heating. The wood of ''Pinus'' grown in Malesia is moderately hard to hard, but the heartwood is not very durable.
Crude resin obtained by tapping living pine trees is a thick, sticky, but usually still fluid material. It is opaque (due to the presence of occluded moisture) and milk-grey. Typically, crude resin comprises 70-75% rosin, 15-20% turpentine and 10% foreign matter (pine needles, insects, etc.) and rainwater. Rosin is the brittle solid remaining as the involatile residue after crude resin has been steam distilled to obtain turpentine. It is insoluble in water but soluble in many organic solvents and consists primarily of a mixture of acids of abietic and pimaric type, with smaller amounts of neutral compounds. Since rosin is an acidic material and the manufacturer of downstream derivatives depends on its acid functionality, a high acid number (and saponification number) is also an indication of good quality. The better quality rosins usually have an acid number in the range 160-170. Rosin derived from ''P. merkusii'' has a higher acid number (190 or more) due to the presence of merkusic acid, a rather rare resin acid with two carboxylic acid groups. Rosin from ''P. merkusii'' in Indonesia is pale brown, has a softening point of 75-78°C, an acid number of 160-200 and a saponification number of 170-210. Anything above about 10% unsaponifiable matter would be considered a poorer quality rosin. The resin acid composition of rosin from ''P. merkusii'' is as follows: 10% sandaracopimaric acid, 15% isopimaric acid, 38% palustric acid, 16% abietic acid, 3% neoabietic acid, 8% dehydroabietic acid and 10% merkusic acid. Rosin from ''P. kesiya'' is dark red-brown; its acid number is 166-168.
Turpentine is a clear, flammable liquid, with a pungent odour and bitter taste. It is immiscible with water and has a boiling point over 150°C and consists of a mixture of organic compounds, mainly terpenes, and its composition can vary considerably (more so than rosin), depending on the species of pine it came from.
Theα-pinene andβ-pinene constituents of turpentine, in particular, are the starting material for synthesis of a wide range of fragrances, flavours, vitamins and polyterpene resin;β-pinene is favoured overαover α-pinene.Δ3-carene is a constituent of turpentine which is not preferred as it is difficult to manipulate. Turpentine from ''P. merkusii'' provenances from Tapanuli (North Sumatra) consists of almost pureα-pinene, various Aceh provenances contain moreΔ3more Δ3-carene, whereas samples from some provenances from Indo-China have a more complex composition with large amounts ofαof α-pinene andΔ3and Δ3-carene and significant amounts of limonene,β-pinene, myrcene and longifolene. Turpentine obtained from ''P. kesiya'' from Aceh (Sumatra) contains 90%α-pinene. The averageαaverage α-pinene content,Δ3-carene content and the turpentine yield for 11 Thai provenances of ''P. merkusii'' were found to be 43-90%, 1-36% and 28-37% respectively. For 5 Philippine provenances theαthe α-pinene andΔ3and Δ3-carene content were 95-96% and 0-1.3% respectively. Provenances from Assam (India) of ''P. kesiya'' have a highβhigh β-pinene content (26-43% of the turpentine) whereas other provenances usually only contain 1-2%β-pinene and more. In Orissa, the composition of turpentine from ''P. kesiya'' is 44%α-pinene and 45%β-pinene.
"Sulphate naval stores" are the by-products recovered during the conversion of pine wood chips to pulp by the sulphate (kraft) pulping process. "Sulphate turpentine" is retrieved by condensation of the alkaline liquors. "Crude tall oil" is fractionated into various products including "tall oil rosin" and "tall oil fatty acids".
== Description ==
*Usually medium-sized, monoecious evergreen trees of 15-45(-70) m tall, usually with a straight bole and a diameter of up to 100(-140) cm; bole without buttresses but distinctly broadened at base in solitary trees; bark usually thick; branches in regular whorls, branchlets glabrous, with a leafless base. *Leaves in mature trees of two kinds: scale leaves which are triangular-lanceolate, early deciduous, bearing the short shoots in their axils, and needle-like leaves, in clusters of 2-4(-5), the latter persistent for two or more years, either semicircular or triangular in cross-section and the margin often minutely toothed. *Male strobili cylindrical, produced in clusters around the base of the young shoot, yellow or reddish, consisting of numerous scales, arranged spirally, each with 2 inverted pollen sacs. *Female cones usually terminal or subterminal, very variable in outline, consisting of scales arranged spirally which are thickened at the apex (called the apophysis), and bearing a stout prickle, mucro or hook (the umbo); each scale bearing 2 ovules. *Seed often egg-shaped with a coat of varying hardness, usually having a large papery wing. *Seedling with hypogeal germination; cotyledons plumose; the primary leaves (scale leaves) appearing within a few weeks and secondary leaves (needle-like leaves) usually appearing during the second year; root system consisting of a taproot with fine roots near the soil surface and near the root tip.
* ''P. kesiya'' : *A large tree up to 45 m tall and up to 100 cm in diameter, bark thick, reticulately and deeply fissured, branchlets often pruinose with a waxy bloom; needles .*Needles in bundles of (2-)3(-4), very slender and flexible, (10-)12-21(-25) cm long, bright grass green; mature .*Mature cones up to 3 together, pendulous, ovoid to ovoid-conical, (4-)5-8(-10) cm long, subsessile or on a short stalk up to 10 mm long; apophysis beaked or flattened with a short, blunt, deciduous umbo; seed .*Seed small with a short wing 1.5-2.5 cm long.
* ''P. merkusii'' : *A large tree up to 50(-70) m tall and up to 55(-140) cm in diameter, bark thick forming plates and grey-brown underneath, but scaly and more reddish tinged upwards, branches heavy, horizontal or ascending; needles .*Needles in pairs, slender but rigid, 16-25 cm long, with persistent basal sheaths; cones .*Cones solitary or in pairs, almost sessile, cylindrical, 5-11 cm long, after opening twice as thick and ovoid, generally falling off soon; apophysis broadly tetragonal with a smooth, almost depressed umbo; seed .*Seed small with a deciduous wing of about 2.5 cm long.
== Growth and development ==
== Other botanical information ==
On a world scale, 10 pine species are tapped commercially. ''P. massoniana'' Lamb. is the most important one yielding the majority of crude resin produced in China. The union of ''P. khasya'' and ''P. insularis'' into ''P. kesiya'' has been argued, because of their different field characteristics and products, and some authors contend that ''P. kesiya'' has not been properly described. In Sumatra three different strains of ''P. merkusii'' have been recognized (the Aceh, Tapanuli and Kerinci strains) which differ markedly in e.g. stem form, branching, bark, resin content and susceptibility to attack by the caterpillars of the moth ''Milionia basalis'' .
== Ecology ==
The naturally occurring pines of South-East Asia ( ''P. kesiya'' and ''P. merkusii'' ) inhabit a wide range of forest and savanna habitats. They are pioneers and their natural range is extended by colonization following disturbances such as fire. They grow, for instance, scattered in fire-prone grassland and woodland. The trees increase in number in recently disturbed areas. They are strongly light-demanding and habitually grow in pure stands. Pines grow naturally in South-East Asia only in strongly seasonal environments.
''P. kesiya'' grows in areas with a mean annual rainfall of 700-1800 mm and a pronounced dry season. Mean annual temperature in the area of distribution is 17-22°C, mean maximum temperature of the hottest month 26-30°C, mean minimum temperature of the coldest month 10-18°C. It generally grows naturally above 1000 m altitude. It is locally common in northern Luzon, often occurring in open pure stands on steep slopes at elevations of 300-2700 m. The best stands are found in moist well-drained localities at high altitudes where the soil is rich enough for hardwoods but because of the elevation the commercial hardwood species cannot thrive.
Vegetative propagation of pines has had only minimal success. Marcotting of ''P. kesiya'' has been found possible with ''Sphagnum'' moss, pine sawdust and pine topsoil as marcotting medium. Marcotting should be done in May-June when pine trees are in a dormant growth stage. Branches in the middle of the crown with a diameter of 2-3 cm are best for marcotting. During dry periods the marcots should be watered.
Seedlings need ectomycorrhiza for optimal growth. Natural infection may occur locally, but a reliable method of inducing seedlings to form mycorrhizal associations is to expose them to saplings of 30-80 cm tall which are already infected. The "mother trees" are planted in the nursery beds a year before sowing, at a spacing of 1 m × 1 m. Another method of obtaining mycorrhiza is to mix ordinary topsoil from pine forests with potting medium (in a ratio of 1 : 4-10), or to inoculate with vegetative mycelia, spores, mycorrhizal capsules or tablets. The latter methods will probably gain importance in the near future. The fungi used for inoculation of pines in South-East Asia include ''Pisolithus tinctorius'' , ''Scleroderma'' sp., ''Thelephora terrestris, Cenoccoccum graniforme'' and ''Rhizopogon'' sp. Root pruning is done when the seedling height is 10-15 cm to reduce shoot growth and to boost root development. After about 8 months the seedlings of ''P. merkusii'' in nursery beds are 20-25 cm tall and ready for planting out in the field. Seedlings of ''P. kesiya'' may already be suitable for transplanting after 4-6 months. Planting out in the field is carried out at the onset of the rainy season at spacings of 4 m × 4 m (for resin production) or 3 m × 1-2 m (for timber production).
Virtually all crude resin production in Indonesia is based on extensive areas of ''P. merkusii'' plantations in Java. In 1991 the production came from about 100 000 ha, but the total area planted to this species in Java is about 400 000 ha and pine plantations are increasing on Sumatra, Kalimantan and Sulawesi. In the Philippines, ''P. kesiya'' is planted at 3 m × 3 m as a shade tree for coffee plantations.
'''== Management''' == Plantation establishment is generally easy, as pines are pioneer species and can be planted in the open. Weeding is done 2-4 times during the first year after planting, the frequency decreasing with increasing size of the trees.
For plantations in Aceh a tapping and thinning schedule has been worked out in which the trees to be thinned are heavily tapped 2-4 years prior to being felled. Between 7 and 19 years 4 thinnings take place, in which 75 trees for the first 2 thinnings and 50 trees per ha in the second 2 thinnings are tapped and removed.
== Diseases and pests ==
Generally, damping-off in pines caused by different fungi in the nursery can be controlled by proper nursery techniques, especially by avoiding over-watering. Stain disease, possibly caused by ''Trichoderma koningii'' , has been observed in 80% of the 21-38-year-old trees in a ''P. kesiya'' plantation in Bukidnon (the Philippines). In the Philippines, bark beetles ( ''Ips calligraphus'' ), pine shoot moths ( ''Dioryctria rubella'' ) and pine tip moths ( ''Petrova cristata'' ) cause problems in plantations of ''P. kesiya'' and ''P. merkusii'' . Pine shoot moths have infested almost all young pine plantations. Their larvae tunnel and feed inside the shoots, thus reducing the quality of the timber. Moreover, they also attack the young cones of ''P. kesiya'' , thus reducing seed production. Pine shoot moths can be effectively controlled by using the insecticides fenitrothion (0.1%) and fenvalerate (0.2%), or by ''Bacillus thuringiensis'' when applied before the larvae bore into the shoots, although their effectiveness to control is also reported to be not significant. The main pests in northern Sumatra are members of the Psychid and Geometrid families (e.g. ''Milionia basalis'' ), shoot- and stem-boring Pyralids, and local squirrels.
== Harvesting ==
== Yield ==
The most important and obvious factor affecting resin yield of pines is the diameter of the trees tapped. There is a linear relationship between tree basal area and resin yield. Moreover, the bigger the proportion of the live crown, the greater the resin yield. The average annual yield of ''P. merkusii'' is 1.4-2.7 kg/tree, for plantations in Java it is 3 kg/tree for ''P. merkusii'' and 1.5 kg/tree for ''P. kesiya'' . The annual yield of ''P. kesiya'' trees with an average diameter of 50 cm in the Philippines is 1.6 kg without the application of a stimulant, and up to 4.1 kg when 60% sulphuric acid is used as a stimulant. The annual resin yield of young ''P. merkusii'' plantations (7-19 years) in Aceh by tapping the trees to be thinned is 340-520 kg per ha, the increase corresponding with the age of the trees. The production of 520 kg of resin is obtained from 50 trees. The minimum acceptable yield is around 2 kg/tree, as lower yields make the operation economically unviable.
Per t wood processed by sulphate pulping 15-20 kg of crude tall oil, i.e. 5-10 kg of tall rosin and 3-5 l sulphate turpentine are obtained.
The genetic variation has been studied in natural populations of ''P. kesiya'' and ''P. merkusii'' in Thailand and Vietnam. In ''P. kesiya'' considerable variability was found between individuals within a population, but only weak variability between populations. Remarkably, the opposite was true for ''P. merkusii'' , with very low variability between individuals of a population but high variability between populations.
International provenance trials of ''P. kesiya'' and ''P. merkusii'' have been established throughout South-East Asia and also in northern Australia; they are coordinated by the Oxford Forestry Institute (Oxford, United Kingdom). ''P. merkusii'' seed orchards have been established in Indonesia.
== Literature ==
* Coppen, J.J.W. & Hone, G.A., 1995. Gum naval stores: turpentine and rosin from pine resin. Non-wood forest products 2. Natural Resources Institute, Chatham, United Kingdom & Food and Agriculture Organization of the United Nations, Rome, Italy. 62 pp.