3050

11: Auxiliary plants

Trema orientalis (L.) Blume

Mus. bot. Lugd.-Bat. 2: 62 (1856).

ULMACEAE

2n = 20, 36, 40

Celtis orientalis L. (1753), Sponia orientalis (L.) Decne (1834), Trema guineensis (Schumach. & Thonn.) Ficalho (1884).

Charcoal tree, Indian charcoal tree (En). Indonesia: anggerung (Javanese), kuray (Sundanese), lenggung (Bali). Malaysia: menarong, mengkirai (Peninsular Malaysia), randagong (Sabah). Philippines: anabiong (Tagalog), pitidan (Igorot), anadgong (Bisaya). Cambodia: srô:l. Laos: po: hu:. Thailand: po-haek (northern), takhai (central), pa-dang (Karen). Vietnam: hu dai, hu l[as] nh[or].

Trema orientalis most probably originated in tropical Asia. It is widely distributed in tropical Africa and from the western Himalayas to the Pacific extending into China and southern Japan, and into Queensland. It is found throughout South-East Asia, though it is rare in the Lesser Sunda Islands (Bali and Nusa Tenggara), the Moluccas, and New Guinea.

The wood is widely used as firewood and provides excellent charcoal which is even suitable for making gunpowder and fireworks. Trema orientalis is often planted as a shade tree in coffee and cocoa plantations and also in other crops in Asia and Africa. Being a pioneer species, it is suitable for planting on poor soils to reforest denuded or disturbed areas. It is common as a fallow species in shifting cultivation. In South Africa it is planted to reforest riverine areas, thereby functioning as the first species in a succession of trees. In the Philippines, Trema orientalis silage is fed to cattle, buffaloes and goats while the bark is used for making ropes and as a source of tannin. The use of leaf meal in feeds is usually limited by the high fibre content and toxins. However, these limitations can be overcome by extracting protein from the leaves. In Malaysia, Indonesia and India, the wood is used in manufacturing panel products such as medium density fibre board (MDF) and particle boards, and also for making paper.

The wood of Trema orientalis has a fairly low density (415—465 kg/m³) and a relatively low energy value (18 900 kJ/kg). However, it is an attractive fuel because of its high heating value and negligible ash content. Silage made from its foliage has a high crude protein content (18.9 g/100 g dry matter) which is comparable to the amount found in common concentrates.
The wood is soft and light, its texture is even, but moderately coarse, with straight or interlocked grain. The sapwood is not distinct from the buff heartwood. Sawing and planing are moderately easy although the surface produced is rough. The wood seasons fairly rapidly, shrinkage is average, but it suffers severe cupping, twist, staining and bowing. It is not durable under exposed conditions. The average length of wood fibres from 7-year-old trees is over 1.6 mm, which compares favourably with that of poplars (Populus spp.) commonly used in the United States for paper manufacture. Fibres are longer in taller trees than in smaller ones and length increases from the pith towards the bark and from the butt to the top of the tree. Paper made of Trema orientalis has good tensile strength and folding endurance.

Deciduous, usually monoecious shrub to large tree, up to 36 m tall, with open crown and spreading branches. Bole up to 90 cm in diameter, sometimes with buttresses up to 1.2 m high; bark smooth to finely fissured, lenticellate, greyish. Branchlets, stipules, petioles, and inflorescences densely set with appressed and matted or erect 1-celled, silvery to glaucous hairs and short, multicellular glandular hairs completely covering the epidermis. Leaves alternate; stipules linear-lanceolate to ovate-acute, 3—4 mm x 1—2 mm; petiole 1—1.5 cm long, often pinkish-purplish; blade ovate to lanceolate, (6—)10—15(—20) cm x (1.5—)2.5—6(—10) cm, often slightly asymmetrical, thinly or thickly leathery, often rigid and brittle, dark green above and glaucous beneath, base cordate, rounded, or sometimes truncate, often contracted, margin serrate to denticulate, apex acute to acuminate-caudate, upper surface scabrid and sparsely set with bulbous-based hairs, lower surface densely covered with matted star-shaped and simple erect hairs; primary and secondary veins sunken above and prominent beneath. Inflorescence a much branched panicle or thyrse, either male or female, borne on separate vegetative branches, at anthesis lax or condensed; axes 1—2 mm thick; bracts ovate-acute, 2—3 mm x 1 mm; flowers 5-merous, tiny, greenish-cream; male inflorescence 2.5(—5) cm long, 20—100-flowered, male flower 1.5—2 mm in diameter, perianth lobes ciliate, 1.5—2 mm x 1 mm, filaments 1—1.5 mm long, anthers about 1 mm x 0.5 mm, pistillode obovoid-conical, compressed; female inflorescence 5—15 flowered, 1.5—2.5 cm long, female flower 2—3 mm x 1—2 mm, perianth lobes ovate, acute, 1.5 mm x 0.5 mm, ciliate and densely short-pubescent, glabrescent, staminodes absent, ovary ovoid-conical, about 2 mm x 1 mm, with 2 slender spreading stigmatic arms. Fruit an ovoid drupe, 5—8 mm x 4—5 mm, glabrous, green turning red, then black, tipped by 2 short styles, seated on the persistent but not enlarged calyx, generally in clusters. Seedling with epigeal germination.

Seed requires a high light intensity for germination. Trema orientalis is very fast growing, attaining harvestable size for pulpwood when 3—4 years old. It coppices well and its extensive root system enables it to withstand dry periods. Flowering and fruiting occurs year-round. Trema orientalis regenerates quickly in forest clearings and may become dominant. After selective logging of Araucaria forest in Papua New Guinea it may thus delay the reestablishment of Araucaria forest by 30—100 years. The fleshy drupes are dispersed by birds.
Several species of the closely related genus Parasponia Miq. form root nodules after Rhizobium infection and can fix atmospheric nitrogen. Early reports of nitrogen fixing nodules being found in Trema orientalis have not been confirmed.

Trema orientalis is very variable in leaf thickness, leaf form, leaf hairiness and fruit size. It is closely related to the similarly distributed Trema tomentosa (Roxb.) Hara, the latter sometimes being included in Trema orientalis as subsp. tomentosa (Roxb.) Murata. Trema tomentosa can be distinguished by its much less densely hairy leaf undersides and concolorous leaves, a larger male inflorescence (up to 5 cm long) and compressed ovoid fruits. It is sometimes assumed that Trema tomentosa is a juvenile form of Trema orientalis.

Trema orientalis is found in the lowland humid tropics (especially in eastern Malesia), extending up to about 2000 m altitude (in western Malesia), even reaching 2500 m (in the Himalayas). It requires 1000—2000 mm annual rainfall and an average annual temperature of 20—27°C. It grows on a wide range of soils from heavy clay to light sand; it tolerates moderate alkalinity and salinity, but does not withstand waterlogging. It is intolerant of fire. Trema orientalis is amongst the first trees to establish in clearings, flood-damaged river-banks and also colonizes denuded, poor soils. In the Philippines, the early tree vegetation in forest clearings left fallow is often composed largely if not entirely of Trema orientalis.

Trema orientalis is propagated by seed or by stump cuttings. To break dormancy, seed has to be steeped in gibberellic acid dissolved in agar at 500 ppm, or stored at 2°C for 3—4 months. In the Philippines, stumps of 2—3-year-old trees, 10—14 cm in diameter at a height of 1.3 m and cut at a height of 30 cm, yield an optimum number of cuttings. Older trees produce fewer sprouts.

Little information is available on the management of Trema orientalis, as wood and fodder are mostly collected from natural stands.

No serious diseases and pests are known. Larvae of Sahyadrassus malabaricus, a sapling borer of Trema orientalis, causes some damage in India, but can be controlled completely with insecticides. Caution is advised if Trema orientalis is to be introduced outside its natural habitat as it may spread insect pests to other plants of economic importance. Ants and rodents favour the fruits.

When harvested for firewood and charcoal, sustained periodic harvests are possible from the same area. Cutting is done every 3—4 years at 20—30 cm above the ground. The cut should be slanting, to prevent the stumps from rotting.

Bark for tanning purposes is often harvested from trees of 40—50 cm stem diameter. The bark yield of such trees is on average 7.8 kg/m² (green weight) and 2.8 kg/m² (air-dried weight).

No germplasm collections or breeding programmes are known to exist.

Because of its easy establishment, fast growth, high heating value, and good palatability and feeding value, Trema orientalis is a potential multipurpose tree. As trees 3—4 years old attain a size suitable for fuelwood and pulpwood, the feasibility of establishing Trema orientalis plantations warrants further research. The leaves have potential as a protein source for non-ruminants in the form of leaf meals, but the nutrient availability and toxicity should be studied further. Trema orientalis is a promising raw material for paper and wall board industries.

Calip, J.E., 1958. The possibility of coppice method propagation of anabiong (Trema orientalis (Linn.) Blume). Philippine Journal of Forestry 14: 183-189.
Lasmarias, V.B., Semana, J.A. & Ballon, C.H., 1981. Effects of wood and pulp properties of wet-formed hardwoods. NSDB (National Science and Development Board) Technology Journal 6: 42-51.
Lin, K.C., 1980. Study on biomass and nutrient content of Trema orientalis (L.) Bl. Quarterly Journal of Chinese Forestry 13: 2, 77-85.
Lopez, M.P., 1953. Study of some factors controlling germination of anabiong (Trema orientalis (Linn.) Blume) seeds. Philippine Journal of Forestry 9: 79-105.
National Academy of Sciences, 1980. Firewood crops: shrub and tree species for energy production. Vol. 1. National Academy Press, Washington, D.C., United States. pp. 68-69.
Philippine Council for Agriculture and Resources Research and Development, 1982. Fuelwood and charcoal utilization. Vol. 4, No 8. PCARRD, Manila, the Philippines. 93 pp.
Razali, A.-K. & Paridah, M.T., 1992. Conversion of high-value panel products from less-used wood species. In: Faridah Hanum, I. et al. (Editors): Indigenous species for forest plantations. Proceedings of a seminar in Malaysia, 23-24 April, 1992. Faculty of Forestry, Universiti Pertanian Malaysia, Serdang, Malaysia. pp. 99-107.
Soepadmo, E., 1978. Ulmaceae. In: van Steenis, C.G.G.J. & de Wilde, W.J.J.O. (Editors): Flora Malesiana. Series 1, Vol. 8. Wolters-Noordhoff, Groningen, the Netherlands. pp. 47-55.

I. Faridah Hanum

Hanum, I.F., 1997. Trema orientalis (L.) Blume. In: Faridah Hanum, I & van der Maesen, L.J.G. (Editors): Plant Resources of South-East Asia No 11: Auxiliary plants. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea