라오스 수종정보1 머르쿠시파인 (Merkusii Pine)

앞으로 몇 번의 포스팅을 통해 라오스의 현지 자생수종중 경제적으로 중요한 몇가지 수종을 소개할 예정이다.

첫 수종은 우리나라 시장에서는 흔히 수마트라파인, 혹은 라오스파인이라고 불려왔던 머르쿠시 파인(Pinus Merkusii)이다. 주로 열대지방의 고산지대에 자생하는 수종으로, 침엽수임에도 불구하고 목질이 강해 건축재나 선박건조재등으로 용도가 많은 수종이다. 또한 가지가 밑에서 부터 총생하여 바람이 많은 지역의 농장등을 보  

Species identity

Taxonomy

Current name: Pinus merkusii

Authority: Junghuhn & de Vriese

Family: Pinaceae

Synonym(s)

Pinus merkusiana Cooling & Gaussen

Pinus sumatrana Junghuhn

Common names

(Filipino) : Mindoro pine, tapulau (Sambali, Tagalog)
(Indonesian) : damar bunga
(Thai) : son-haang-maa (central)
(Vietnamese) : th[oo]ng hai l[as]

Botanic description
A large tree up to 50(-70) m tall with a straight and cylindrical bole free of branches for 15-25 m and an average diameter of 55 cm, but occasionally up to 140 cm, thick bark which forms plates and is grey-brown underneath, but scaly and more reddish tinged upwards, and heavy horizontal or ascending branches. Needles in pairs, slender but rigid, 16-25 cm long, with persistent basal sheaths. 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 small with a deciduous wing of c. 2.5 cm long. The normal architecture of pines is Rauh's model. The trunk is monopodial and grows rhythmically, and develops tiers of branches; the formation of cones does not affect shoot construction. Sometimes ""foxtails"" occur, plants without branching and without growth rings in the wood. Merkus pines of the Asian mainland and the Philippines differ slightly from those of Sumatra: the seedlings have a ""grass stage"", the needles are slightly longer, the cones are less cylindrical, and the seeds nearly twice as heavy. 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 moth Milionia basalis.

Ecology and distribution

History of cultivation
Eastern Burma, Indo-China, southern China, northern Thailand, the Philippines (Mindoro, western Luzon), Sumatra (Aceh, Tapanuli, Kerintji mountain); commonly planted in South-East Asia.
Natural Habitat
It is the southernmost occurring pine of all pines, and the only one whose natural distribution extends into the southern hemishpere. 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 are increasing 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.
Eastern Burma, Indo-China, southern China, northern Thailand, the Philippines (Mindoro, western Luzon), Sumatra (Aceh, Tapanuli, Kerintji mountain); commonly planted in South-East Asia.

Biophysical limits
Altitude: Up to 2000 m; Mean annual rainfall: 1000-2800(-3500) mm; Mean annual temperature: 21-28 deg.C; Mean maximum temperature of the hottest month: 24-32 deg. C; Mean minimum temperature the coldest month: 18-24 deg. C.

Reproductive Biology
In plantations, trees of P. merkusii reach sexual maturity when about 20 years old. They bear cones every year, although seed production varies. In Sumatra ripe seeds are produced most abundantly between July and November, but viable seeds are produced throughout the year.

Propagation and management

Propagation methods
Successful natural regeneration is only possible where a relatively large amount of sunlight reaches the ground. In Sumatra ripe seeds are produced most abundantly between July and November, but viable seeds are produced throughout the year. Only cones that have just changed their colour from green to brown should be collected and air dried. Seeds germinate in 8-12(-21) days, and need no pretreatment. However, they are often soaked in cold water overnight before sowing. A germination rate of P. merkusii seeds of 40-60% may be expected. After about 8 months the seedlings of P. merkusii in nursery beds are 20-25 cm tall and ready for planting into the field. Propagation by tissue culture is possible. Suspensor, root tissue and hypocotyl segments of 2-week-old seedlings of P. merkusii have been used, and they all readily yield callus when cultured on a Murashige and Skoog mineral formulation supplemented with naphthalene acetic acid (0.25-0.65 ppm) and benzylamino purine (1.0-2.0 ppm).

Tree Management
Husbandry: In plantations of P. merkusii the first thinning is usually carried out in the 9th or 10th year, and about every 5 years thereafter. Rotation cycles of 30 years are needed for optimal timber production and have been stipulated by the Indonesian forestry administration. For the production of pulpwood, a cutting cycle of 15 years is usually practised. Mycorrhizae are required for successful growth and allow seedlings to survive in more adverse sites. P. merkusii and P. kesiya require more weeding than P. caribaea and P. oocarpa. The prolonged ""grass stage"" often present in young trees of P. merkusii means increased weeding requirements when compared to P. caribaea, P. oocarpa and P. kesiya.

Germplasm Management
The seeds can be stored for several years, provided they are kept dry, cold and in an airtight container. However, seeds of P. merkusii are reported to have a rather short viability; seeds from Sumatra can be stored dry for only 1-2 years, and those from continental Asia during even shorter periods. The weight of 1000 seeds of Sumatran P. merkusii about 17 g, and of continental provenances of P. merkusii 25-33 g.

Functional uses

Products
Gum or resin: Good quality oleoresin is collected from this species, often on plantation scale. Timber: Merkus pine is a general-purpose timber; it can also be used for construction work, flooring and boat building as it is fairly durable and heavy.

Services
Intercropping: In Indonesia P. merkusii has been successfully intercropped with Irish potatoes. Shade or shelter: The tree is used to shade out alang-alang grass with fairly good results.

Additional Information

Development
Young trees of mainland provenances of P. merkusii pass from 3-5 years through a so-called ""grass stage"" characterized by densely clustered needles and short shoots and minimal height growth. However, Sumatran provenances of the same species have no ""grass stage"" and they grow quickly upwards. This improves their chances in the competition with weeds which grow vigorously in the moist climate.

Properties
Timber (paragraph 1): The density of heartwood of P. merkusii from Sumatra is 565-750 kg/m cubic at 15% moisture content. The density of timber of the same species grown in Burma and Indo-China is normally less: 480-530 kg/m cubic. Test in Indonesia at green condition showed the following mechanical properties: modulus of rupture is 53 N/mm cubic, modulus of elasticity 10 290 N/mm cubic, compression parallel to grain 26 N/mm�, compression shear 6-7 N/mm cubic, cleavage radial 39 N/mm, cleavage tangential 38 N/mm, janka side hardness 2450 N and janka end hardness 2705 N. At 15% moisture content, modulus of rupture is 83 N/mm�, modulus of elasticity 12 445 N/mm cubic, compression parallel to grain 44 N/mm cubic, compression shear 8-9 N/mm cubic, cleavage radial 42 N/mm, cleavage tangential 55 N/mm, janka side hardness 3800 N and janka end hardness 4790 N. Test in Malaysia at 159% moisture content showed the following mechanical properties: modulus of rupture is 32 N/mm cubic, modulus of elasticity 4600 N/mm cubic, compression parallel to grain 15 N/mm cubic, compression shear 7 N/mm cubic, cleavage radial 35 N/mm, cleavage tangential 36 N/mm and janka side hardness 2310 N. At 15% moisture content, modulus of rupture is 41 N/mm cubic, modulus of elasticity 4600 N/mm cubic, compression parallel to grain 24 N/mm cubic, compression shear 10 N/mm cubic, cleavage radial 38 N/mm, cleavage tangential 46 N/mm and janka side hardness 3200 N. The rates of shrinkage from green to oven dry 4.9% radial and 8.3% tangential. Timber (paragraph 2): Seasoning properties of P. merkusii timber are good and no serious difficulties are encountered, provided stock is converted soon after felling and protected during drying. Kiln-drying properties are rated as good, but resin and staining may cause problems. High-temperature drying (at 115 deg. C) takes 24 hours for boards 2.5 cm thick and 48 hours for boards 5 cm thick; no serious defects develop. For wood of P. merkusii in Indonesia, a drying temperature of 54-82 deg. C and a corresponding relative humidity of 76% to 30% is recommended. Timber (paragraph 3): Pine timber is only moderately durable, and often prone to termite attack. It is also susceptible to blue stain, ambrosia beetles and dry-wood borers. Graveyeard tests on P. merkusii in Indonesia showed a service life in contact with the ground of 1-4.5 years. Heartwood of P. merkusii can be impregnated with CCA preservative quite well; it is classified as ""permeable"". Timber (paragraph 4): Wood of P. merkusii contains 55% cellulose, 24% lignin, 14% pentosan, 1.1% ash and 0.2% silica. The solubility is 6.3% in alcohol-benzene, 0.4% in cold water, 3.2% in hot water and 11.1% in a 1% NaOH solution. Timber (paragraph 5): Distinguishing characteristics: P. merkusii is typically a hard pine anatomically; the wood is more dense, the transition from earlywood to latewood more abrupt and vertical resin ducts are larger than in P. kesiya. Fuel: The energy value of the wood is 20 300-23 200 kJ/kg. Medicine: Ethyl alcohol extracts of P. merkusii showed anti-cancer activity in tests in the Philippines.

Yields
Harvesting: Several methods of harvesting the resin are practised. The resin is found in the intercellular canals in the wood (especially sapwood) and products are often termed ""naval stores"" because of their historic use for ship caulking. Living pine trees are tapped (wounded), the first cut of about 1.3 cm wide and 30 cm long being made 30-40 cm from the ground, followed by a series of chippings until breast height. A sulphuric acid solution (usually 40-60%) is applied immediately after chipping. This process yields the ""gum naval stores"", still the major source of the worlds supply of rosin and turpentine. ""Wood naval stores"" can be obtained by solvent extraction of stumps of old trees; the resin obtained in this manner is less pure. Turpentine and wood resin can also be obtained as by-products from the kraft (sulphate) pulping of pines. Turpentine is removed from the chip digester during the initial steaming and condensed from the relief gases. This method gives ""kraft naval stores"". Yield: For an average site quality (4) the mean annual increment of P. merkusii is 22.4 m�/ha in a 25-year rotation, but it may reach 30 m�/ha for better site quality (6) in a 20-year rotation. In Sumatra 30-year-old stands of P. merkusii trees (with an average diameter of 58.5 cm) may have a standing volume of 397 m�/ha with a total yield of 814 m�/ha. The yield of resin from P. merkusii is 420-750 kg/ha.

Genetic
Genetic resources and breeding: The standard seed source areas for P. merkusii are Sumatra and Thailand. Seedlings raised from Sumatran seeds often miss the ""grass stage"" and are thus better suited for plantations. The sources of genetically superior P. merkusii seed in Sumatra should be protected. The natural areas of distribution of this species in Malesia are comparatively small, and for this reason, protection of natural stands should be guaranteed. 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 Commonwealth Forestry Institute of Oxford (UK). In Thailand, trials of provenance hybrids of P. merkusii showed that hybrids of Thailand and Papua New Guinea provenances had better survival and length-growth than local provenances. P. merkusii seed orchards have been established in Indonesia.

Prospects

Pines are much planted trees because of their fast growth, ability to grow on comparatively poor soils and at high altitudes, and because of the detailed information available on their silviculture. The quality of the wood is, however, often very poor. The production of better quality wood from pine plantations should be a research priority.