Schima (PROSEA)
Introduction |
Schima Reinw. ex Blume
- Protologue: Catalogus: 80 (1823).
- Family: Theaceae
- Chromosome number: x = unknown; S. wallichii: 2n = 36
Vernacular names
- Mang tan, simartolu (trade names). Needle wood, schima (Am, En).
- Brunei: kelinchi padi
- Indonesia: puspa (trade name), madang gatal (Kalimantan), seru (Sumatra, Java)
- Malaysia: medang gatal (trade name), gatal-gatal (Sabah), samak (Peninsular)
- Papua New Guinea: schima (En).
- Burma (Myanmar): laukya
- Laos: boun nak, 'khai1sou2, 'mi
- Thailand: bunnak (south-eastern), champa dong (north-eastern), thalo (northern)
- Vietnam: vối thuốc.
Origin and geographic distribution
Schima is a wide-ranging monotypic genus occurring from north-eastern India through Indo-China, southern China, the Ryukyu Islands and the Bonin Islands to Thailand, Peninsular Malaysia, Sumatra, Java, Borneo and the Philippines (Palawan). The only species, S. wallichii (DC.) Korth. (synonyms: S. bancana Miq., S. crenata Korth., S. noronhae Reinw. ex Blume), is fairly widely grown in South-East Asia and locally naturalized.
Uses
The wood of S. wallichii is used for medium-heavy construction under cover (columns, beams), flooring, interior fitting, panelling, door and window frames, joinery, utility furniture, ship and boat building (ribs, decks), vehicle bodies, agricultural implements, pallets, boxes and crates, poles, toys, turnery and, when treated, for railway sleepers. It has been used for bridge building in mountain areas and young trees have been applied as rafters. A good quality plywood can be manufactured from the wood and it is suitable for the production of wood-wool boards. It also yields good firewood.
S. wallichii is useful for reforestation, also in relation to water conservation in catchment areas, and has been planted along roads. In Indonesia it has been used as a cover crop in plantations of Pinus merkusii Jungh. & de Vriese and Agathis dammara (Lambert) Rich. In India it has been used as a shade tree in coffee plantations. The astringent corollas are used to treat uterine disorders and hysteria, and also as an ointment to treat smallpox. In Indonesia the crude drug is called "buah cangkok", in Peninsular Malaysia "changkoh". The bark contains an alkaloid used for fish poison. In Nepal its leaves are used for fodder.
Production and international trade
"Samak" is the trade name for timber of the genera Schima , Adinandra and Gordonia , all belonging to the Theaceae , but use is mainly on a local scale. Small amounts of Schima timber are exported from Sabah and Sarawak to Japan. In 1996 Papua New Guinea exported about 1655 m3of "schima" logs at an average free-on-board (FOB) price of US$ 99/m3. There is an industrial forest plantation of S. wallichii in South Sumatra.
Properties
S. wallichii yields a medium-weight to heavy hardwood with a density of 450-920 kg/m3at 15% moisture content. Heartwood pink-brown, red-brown or grey-brown, sometimes dark red-brown, not clearly differentiated from the pale grey sapwood; grain straight or interlocked, frequently irregular; texture moderately fine or fine and even. Growth rings distinct to indistinct, when distinct demarcated by layers of darker coloured tissue without vessels; vessels moderately small to medium-sized, oval rather than angular as in most Theaceae , mostly solitary, but overlapping ends of a vertical series frequently appear as diagonal pairs, tyloses rare; parenchyma moderately abundant, apotracheal diffuse and diffuse-in-aggregates, visible with a hand lens; rays very fine to moderately fine; ripple marks absent.
Shrinkage is moderate to very high and the timber seasons fairly rapidly; 13 mm and 38 mm thick boards were observed to take about 2.5 months and 3 months, respectively to air dry in Malaysia. Figures from Indonesia indicate slower air drying, e.g. 7 months for 30 mm thick boards, with slight to severe risk of cupping, bowing, twisting or splitting. The wood is moderately hard and fairly strong. It is easy to work with hand and machine tools and polishes satisfactorily. The wood is durable under cover; in graveyard tests in Peninsular Malaysia it was destroyed in 3.5-4 years, which classifies it as moderately durable. Preservative treatment is easy to difficult, absorption in S. wallichii subsp. noronhae (Reinw. ex Blume) Bloembergen var. noronhae is 69-161 kg/m3with mixtures of creosote and residue oil. The wood is relatively resistant to dry-wood termites.
The energy value of the sapwood is about 19 980 kJ/kg. The leaves of S. wallichii contain tannin, but too little to be used for tanning. The bark contains fine fibres which may cause skin irritation. Seed of S. wallichii from India contains 19% oil.
See also the tables on microscopic wood anatomy and wood properties.
Botany
An evergreen, medium-sized to large tree up to 47 m tall; bole cylindrical, branchless for up to 25 m, up to 125(-250) cm in diameter, rarely with up to 1.8 m high steep buttresses; bark surface ruggedly cracked into small thick angular pieces, red-brown to dark grey, inner bark with irritating fibres, bright red. Leaves arranged spirally, simple, entire to coarsely toothed, exstipulate. Flowers solitary in axils at the apices of twigs, with 2 bracteoles, 5-merous; sepals subequal, persistent in fruit; petals connate at base; stamens many, adnate to the corolla base, anthers versatile; ovary superior, 5-locular with 2-6 ovules in each cell, style simple. Fruit a woody, subglobose capsule. Seed winged all around. Seedling with epigeal germination; cotyledons emergent, leafy; hypocotyl elongated; all leaves arranged spirally, involute to almost conduplicate.
Growth is according to Rauh's architectural tree model, characterized by a monopodial trunk with rhythmic growth and tiers of branches that are themselves morphogenetically identical with the trunk, flowers having no effect on the growth of the shoot system. Early growth is comparatively slow, accelerating later. A 28-year-old plantation of S. wallichii subsp. noronhae var. noronhae in West Java had an average diameter of 24 cm and an average height of 22 m. Trees may flower and fruit already after four years. Flowering and fruiting occurs throughout the year, but flowers are usually most abundant around the seasonal changes. In India trees bear flowers in April-June whereas the first fruits are observed from the end of May to July. The seeds are shed in January to March of the next year. In Indonesia fruiting is reported to be most abundant in August to November. Seeds are dispersed by wind.
S. wallichii is highly variable and was formerly thought to comprise many distinct species. At present it is subdivided into 9 subspecies mainly differing in leaf characteristics; some of these are further split up into varieties. The correctness of these subdivisions is sometimes questioned.
Ecology
S. wallichii is a common tree that can grow in a wide range of climates, habitats and soils. It is found in perhumid to seasonal climates. It often occurs gregariously in primary lowland to montane forest, up to 2400(-3900) m altitude, but is particularly common in disturbed and secondary forests, scrub and grassland and even in areas inundated by brackish water. It usually prefers well-drained soils, but has been observed in swamps and along rivers, and is not choosy about soil texture and fertility.
Silviculture
S. wallichii can be raised from seed; the use of cuttings has not been successful. The woody capsules should be collected before dehiscing and seeds can be extracted after drying when the capsules open. There are 196 000-267 000 dry seeds/kg. Dried fruits or seeds can be stored for up to three months, although one record from Nepal shows that they can be stored for a long time without problems. It has been stated that the seed needs "after-ripening" of about 2 weeks. Germination rates vary considerably: seeds of S. wallichii gave about 90% germination in 10-12 days, but in another seedlot the germination rate was only 15% in 23-85 days. In general, germination attains 25-55%. Wildlings have been collected from natural regeneration in plantations. Seeds are sown under shade and only lightly covered with soil. Seedling mortality in the nursery is usually about 50%. After 2-3 months seedlings are 5-8 cm tall and can be transplanted from the seedbed to containers; at 6-8 months, when they are about 20 cm tall, they can be planted out in the field, although stumps may be made of older seedlings. Survival of planted-out seedlings is almost 100%. In Peninsular Malaysia they are planted at 1.8 m × 1.2 m or 3.6 m × 1.8 m spacing resulting in almost double diameter increment in the wider spacing. Silviculturally, S. wallichii is also variable and different subspecies have quite different characteristics, e.g. pioneer characteristics and capacity of natural pruning. It is usually considered a moderate light demander and regenerates abundantly where sufficient light is admitted for the development of the seedlings, but it is also stated to be a shade-bearing species which hardly regenerates even in small gaps ( S. wallichii subsp. noronhae var. noronhae from the mountains of Java). For Peninsular Malaysia it is stated that its strong forking and persistent branching, even when densely planted, is a serious drawback; this probably refers to the naturally occurring S. wallichii subsp. oblata (Roxb.) Bloembergen. It is stated that the trees of subsp. noronhae var. noronhae and subsp. bancana (Miq.) Bloembergen have a long clear bole and that natural pruning is good. S. wallichii coppices easily and is fairly resistant to fire from the age of five and then reproduces by coppice shoots. The borer Trachylophus approximator has been observed tunnelling in stem bases in Java, enhancing secondary diseases and pests.
Genetic resources and breeding
The variability in wood characteristics and silvicultural behaviour between subspecies of S. wallichii is striking and offers scope for future selection and breeding. Meanwhile, some subspecies have a very small area of distribution and their use may impair their genetic conservation.
Prospects
S. wallichii has good potential for plantations in South-East Asia due to its ease of handling in the nursery, its easy establishment and satisfactory growth rate.
Literature
40, 57, 70, 75, 80, 101, 118, 130, 161, 162, 163, 198, 209, 240, 259, 260, 267, 308, 328, 387, 388, 405, 436, 479, 518, 526, 536, 546, 632, 634, 635, 677, 678, 701, 757, 829, 831, 922, 933, 947, 1039, 1104, 1169, 1177, 1199, 1221, 1234, 1239, 1242.
E. Boer & M.S.M. Sosef