Altingia (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Altingia Noroña

Protologue: Verh. Batav. Genootsch. Kunsten 5, art. 2: 1 (1790).

Family: Hamamelidaceae

Chromosome number: x= probably 8; 2n= 32

Trade groups

Rasamala: medium-weight hardwood, a single species, Altingia excelsa Noroña, Verh. Batav. Genootsch. Kunsten 5, art. 2: 1 (1790).

Vernacular names

Rasamala

• Indonesia: mala (Java), tulasan (Sumatra), mandung (Minangkabau)
• Burma: nantayok
• Laos: sop
• Thailand: sop, hom (northern), satu (eastern)
• Vietnam: tô hạp lá hình tim.

Origin and geographic distribution

Altingia consists of 8 species and is distributed from southern Tibet, Assam (India) and mainland South-East Asia including southern China towards the Malesian area. Only a single species is represented in Malesia: A. excelsa. This species is distributed from the Himalayas through the moister parts of Burma towards Peninsular Malaysia (where it is extremely rare), Sumatra and West Java. It is planted for reforestation (mainly West and Central Java).

Uses

Rasamala is regarded as the most valuable timber in West Java. Because of its ability to form very long branchless boles, it was favoured for frames of bridges and columns and beams for buildings. The wood is very durable and can be used in direct contact with the ground, for example for power transmission poles, telephone line poles and railway sleepers. However, poles and sleepers are often made of wood from young trees (especially from thinnings); they are not durable then and should be treated with preservatives. Furthermore, the timber is used for heavy construction, vehicle bodies, ship and boat building, heavy flooring and rafters. The wood yields a veneer and plywood of suitable quality and gives good results in the manufacture of wood-wool boards. Pulp for the manufacture of paper can also be obtained from rasamala wood.

The bole yields an aromatic resin, called "getah malai", which is collected and used as an incense. Small bees (Apona spp.) which inhabit hollows in the trunk collect the resin and use it to build their combs. Resin collected from these combs is called "getah kandai". Young leaves (flushes) emit a pleasant aromatic odour when crushed and in Indonesia they are mixed in a salad ("lalab") or cooked and eaten as a vegetable. When masticated, the leaves have also been used to cure coughs and in traditional medicine on Java. The dried bark has been used as tinder.

Production and international trade

No production and trade statistics are available for rasamala. The wood is not exported, and is used only locally.

Properties

Rasamala is a medium-weight hardwood. The heartwood is dark pinkish, red or reddish-brown, gradually merging into the yellowish or reddish-brown sapwood. The density is 610-900 kg/m³at 15% moisture content. The grain is straight to slightly interlocked, texture fine and even.

At 15% moisture content, the modulus of rupture is about 102 N/mm², the modulus of elasticity 9000 N/mm², compression parallel to grain 59 N/mm², shear 5-6 N/mm², cleavage 65 N/mm radial and 90 N/mm tangential, Janka side hardness 6200 N and Janka end hardness 6200 N. See also the table on wood properties.

The rates of shrinkage are high, from green to oven dry 5.6% radial and 11.6% tangential. Rasamala dries slowly and with considerable defects; it is prone to cupping, twisting, and checking at the knots, especially in pieces with interlocked grain. The wood must be dried carefully and stacked properly, especially during kiln drying. The air drying of 2 cm thick boards to 15% moisture content takes over 5 months, and boards of 3 cm thick require almost 7 months to dry. The recommended temperature for kiln drying is 38-60C with a corresponding relative humidity of 86% to 38%.

Rasamala is easy to work and to saw. Tests on the machining properties show very good results for planing, boring, mortising and sanding, whereas turning is rated as good. Veneer of 1.5 mm thick can be made at a peeling angle of 91after boiling for 24 hours; gluing with formaldehyde produces good-quality plywood.

Rasamala is classified as moderately durable to very durable. Graveyard tests under tropical conditions showed an average service life in contact with the ground of 12.7 years. However, graveyards tests of rasamala wood from plantation forest indicate a lesser durability, possibly because of the faster growth and younger age of the trees. Laboratory tests show that the wood is moderately resistant to resistant to dry-wood termites. The wood is moderately resistant to impregnation by the full cell process.

The wood contains 46% cellulose, 30% lignin, 17% pentosan, 1.4% ash and up to 0.7% silica. The solubility is 1.5% in alcohol-benzene, 2.4% in cold water, 2.8% in hot water and 14.4% in a 1% NaOH solution. The energy value of the wood is 20 220 kJ/kg.

Description

• A monoecious, evergreen, large and lofty tree of up to 50(-60) m tall; bole branchless for 20-35 m, 80-150(-185) cm in diameter, often slightly twisted or fluted at base; bark surface almost smooth, with narrow, longitudinal fissures and finally irregularly flaky with long, thin, light grey to yellowish or brownish-grey flakes; crown irregularly globular, that of juvenile specimens conical and acute; branches generally steeply ascending.
• Leaves arranged spirally, simple, elliptical to oblong or ovate to ovate-lanceolate, 6-12(-16) cm × 2.5-5.5(-6.5) cm, rounded to slightly cordate at base, acute to acuminate or sometimes caudate at the apex, pinnately veined; margin glandular crenate-serrate; upper surface glabrous, lower surface glabrous to puberulous; petiole usually with sessile or shortly stalked glandular appendages at the apex; stipules very small, caducous.
• Inflorescence consisting of peduncled male or female heads, initially enveloped by 4 bracts.
• Male heads 6-14 per inflorescence, in 1-2 cm long racemes, consisting of masses of short stamens, perianth, disk and ovary absent, anthers with 4 pollen sacs, dehiscing with longitudinal slits.
• Female head solitary, globose to subglobose, 6-9 mm × 5-8 mm, puberulous, 4-18-flowered, stamens rudimentary or absent, flowers without perianth but with disk consisting of a variable number of minute lobes, ovary³/4-inferior, 2-celled, with numerous ovules in each cell, styles 2, divergent and often strongly recurved, with decurrent, papillose stigmas.
• Fruit head 1.2-2.5 cm × 1.2-2 cm, woody, on a 2-3.5 cm long peduncle; fruit 4-valved, surrounded by a ring of enlarged, hardened disk lobes, light brown puberulous at the apex.
• Fertile seeds 0-1(-2) in each cell, dorso-ventrally flattened, obovate, surrouded by a narrow wing, sweet scented; sterile seeds up to 35 in each cell.
• Seedling with epigeal germination; cotyledons foliaceous, on a hairy petiole; leaves arranged spirally.

Wood anatomy

Macroscopic characters

Heartwood pink to dull reddish-brown, indistinctly demarcated from the somewhat lighter sapwood. Grain straight, irregular to somewhat interlocked. Texture fine and even. Wood usually dull but with some lustre on radial surfaces. Growth rings wide and prominent macroscopically (1-2/cm); vessels, parenchyma and rays not visible without a hand lens.

Microscopic characters

• Growth rings tending to be distinct, marked by a narrow band of thicker-walled fibres with fewer vessels.
• Vessels diffuse, 26-48/mm², predominantly solitary but long overlapping vessel segment tips produce pairs in transverse section, evenly distributed throughout the growth ring but reduced in the latewood, tending to be larger in the middle of the ring but generally exhibiting little variation throughout the growth ring, rounded or angular, 60-110μm in diameter; perforation plates scalariform, with 15-30 thin bars; intervessel pits scalariform, up to 50μm in horizontal diameter, with prominent borders; vessel-ray pits half-bordered with reduced borders to almost simple, mostly confined to upright cells, oblique to horizontally scalariform, up to 35μm.
• Fibres 1100-2700μm long, non-septate, moderately thick- to thick-walled; fibre pits in radial and tangential walls distinctly bordered with maximum diameter up to 10μm; gummy deposits occasionally present.
• Parenchyma apotracheal, scarce to fairly abundant, diffuse and tending to diffuse-in-aggregates with 2 to several cells spanning the rays, cells tending to be flattened tangentially, strand length 2-6 cells, gummy deposits relatively plentiful. Rays 8-11/mm, conspicuous on radial surfaces because of gummy deposits, up to 1(-2.2) mm high, heterocellular with up to 3 upright marginal cells, 1-4(-5) cells wide and up to 40 cells high, sometimes linking axially; few low rays mainly uniseriate, 2-15 cells high and consisting of upright cells.
• Enlarged prismatic crystals often present in upright ray cells.
• Silica usually absent.
• Traumatic gum ducts occasionally present in narrow tangential bands.

Growth and development

The growth of seedlings is slow for the first few years, but is rapid later. Seedlings tolerate shade. Trees attain an average height of 14 m and an average diameter of 12.5 cm in 10 years, 22 m height and 23 cm diameter in 20 years, 34.5 m height and 39.5 cm diameter in 40 years, and 47 m height and 61.5 cm diameter in 80 years. The growth rates strongly depend on elevation; growth is fastest at 600-700 m altitude.

Rasamala occurs in more or less pure stands. There are indications that inbreeding is common because of the presence of "family clumps" in the forest.

Flowers appear together with new flushes. Although rasamala flowers every year, in certain years the tree blossoms more abundantly. In Java, rasamala flowers particularly in April - May. The best seeds are obtained from fruits produced in August - October. The seeds have a sweetish scent, and are dispersed by ants. Monkeys and birds may contribute to the dispersal as well, by eating the seeds.

Other botanical information

Altingia belongs to the more primitive genera of the Hamamelidaceae. Together with the Asiatic genus Semiliquidambar and the more or less pantropical genus Liquidambar it is grouped in the subfamily Altingioideae. This subfamily has a rather isolated position, deviating from the rest in various ways, including features of wood anatomy, the unisexual flowers, pollen type and cytology. It has been suggested that this subfamily be promoted to a family level (Altingiaceae). The genus Altingia is divided into 2 sections: section Altingia and section Oligocarpa H.-T. Chang on the basis of their fruiting heads. The records for Thailand of A. excelsa probably all refer to the closely related A. siamensis Craib.

Ecology

Rasamala is a characteristic element of humid mixed hill and montane forest. It often occurs gregariously and forms the backbone of the forest at altitudes between 550 and 1700 m where precipitation is at least 100 mm during the driest month. When planted outside its natural distribution area, it will tolerate less rainfall. Rasamala occurs on rich, well-drained volcanic soils or sometimes on the better soils overlying sedimentary rock. In primary forest 10-35 specimens may be encountered per ha containing (50-)75-85% of the total timber volume. Its principal associates are Podocarpus and Quercus species and further a number of elements of this type of montane forest such as Schima, Castanopsis, Eugenia, Sloanea, Dysoxylum, Engelhardtia, Magnolia, Michelia, and Elaeocarpus species.

Propagation and planting

Rasamala was first planted in the mid-19th Century. Originally, seedlings from natural regeneration in the forest were used (natural regeneration is usually plentiful, even in plantations), but later the seeds were sown on seed-beds. Fruits contain up to 35 seeds, but usually only one of these is fully developed and viable. The best way to obtain viable seeds is to pick nearly ripe fruits and dry them in the sun. The weight of 1000 seeds is about 6 g.

Seeds are viable for a short period and should be sown rapidly. They start to germinate after about 10 days; the germination rate of fresh seed is reported to be 40%. It is not recommended to use stumps for plantation establishment as this often results in multiple leaders. The usual planting distance is 1 m × 3 m, but on steep slopes 1 m × 2.5 m is used.

Silviculture and management

Leucaena leucocephala (Lamk) de Wit is often interplanted in young plantations to suppress weeds. Interplanting with other timber trees is not recommended. Young rasamala trees tend to form double leaders when much light is available, and therefore close planting in pure stands is preferable. Thinning is needed about every 5 years. The rotation is at least 60 years, but preferably 80 years.

Diseases and pests

The fungus Rhizoctonia sp. may cause damping-off of seedlings in nurseries. Root and bark borers such as Endoclita sericeus may cause damage in young plantations, as well as caterpillars like Eutelia inextricata and Cricula trifenestrata which feed on the leaves. Exopholis hypoleuca and Leucopholis rorida are pests of young plantations but can be controlled by using insecticides.

Harvesting

Selective cutting of rasamala trees started several centuries ago. Rasamala timber was in great demand for building purposes. Nowadays it is still selectively harvested in Indonesia under the selective felling system, with a diameter limit of 60 cm and leaving 25 healthy trees/ha as core trees for future harvest. Harvesting is often not easy in the hills and mountains where rasamala occurs naturally. Yarding can be done by cable. It is difficult to transport the logs in mountainous terrain, especially because of their large size and the high density of the wood.

Yield

The average annual production of timber in plantations is 9-13 m³/ha. On sites of reasonable quality, a pure rasamala plantation of 60 years old may have a timber volume of 450 m³/ha. Natural stands may yield 100-150 m³/ha.

Genetic resources

Rasamala forests, natural and planted, are threatened in many areas by harvesting of firewood, conversion into rice fields and tea plantations, and cattle grazing. However, at present comparatively large stands of rasamala still thrive in many different areas and therefore genetic resources seem still to be sufficient. In Java, mountain people distinguish 3 types of trees based on the colour of the wood: "mala beureum" for light red or flesh-coloured wood, "mala gadok" for dark red wood and "mala taribih" for very dark red wood. When looking for genetic variability in A. excelsa, the variation in wood colour could be taken into consideration.

Prospects

The prospects for rasamala as a producer of construction timber in areas at higher altitude (500-1000 m) are promising. The wood has good properties and it is available in large sizes. The quality of plantation-grown wood should, however, be further investigated.

To avoid the depletion of resources, regeneration should be promoted by enrichment planting. Large-scale planting in pure stands is profitable. Seed-orchards of rasamala must be designated and managed appropriately, as good-quality seed for establishing plantations is often not available. Research should be done on the optimal methods of vegetative propagation.

Literature

• Beekman, H.A.J.M., 1949. Houtteelt in Indonesië [Silviculture in Indonesia]. Publicatie No 33, Fonds Landbouw Exportbureau 1916-1918. H. Veenman & Zonen, Wageningen. pp. 246-268.
• Ferguson, D.K., 1989. A survey of the Liquidambaroideae (Hamamelidaceae) with a view to elucidating its fossil record. In: Crane, P.R. & Blackmore, S. (Editors): Evolution, systematics, and fossil history of the Hamamelidae. Vol. 1. Introduction and "lower" Hamamelidae. Systematics Association Special Volume No 40A. Clarendon Press, Oxford. pp. 249-272.
• Ferguson, J.H.A., 1937. Rasamala - Altingia excelsa Noronha as a cultivated tree. Tectona 30: 235-280.
• Jafarsidik, Y., 1986. Hardwood forest tree plantations in Sumatra. Indonesian Agricultural Research and Development Journal 8: 7-11.
• Martawijaya, A., Kartasujana, I., Mandang, Y.I, Prawira, S.A. & Kadir, K., 1989. Atlas kayu Indonesia [Indonesian wood atlas]. Vol. 2. Forest Products Research and Development Centre, Bogor. pp. 112-117.
• Ruhandi, A.E.P., 1980. Pengusahaan hutan rasamala di KPH Bandung Selatan [Management of rasamala forest in the South Bandung Forest District]. Duta Rimba 37(6): 3-7.
• Sakai, K.I., Endo, T., Tyama, S., Miyazak, Y., Hayashi, S., Shimamoto, Y., Gadrinab, L.U. & Juniarti, U., 1987. Studies on the breeding structure of tree species in the tropical rain forest. I: Family clumps and intrapopulation differentiation. Biotropica 1: 1-25.
• Sakai, K.I., Rumbino, A., Iyama, S. & Gadrinab, L.U., 1987. Studies on the interference among trees in a plantation of Altingia excelsa. Biotropica 1: 26-40.
• Vink, W., 1957. Hamamelidaceae. In: van Steenis, C.G.G.J. (Editor): Flora Malesiana. Ser. I, Vol. 5. Noordhoff-Kolff N.V., Djakarta. pp. 363-379.
• Whitmore, T.C., 1983. Hamamelidaceae. In: Whitmore, T.C. (Editor): Tree flora of Malaya. 2nd edition. Vol. 2. Longman Malaysia SDN Berhad, Kuala Lumpur. pp. 237-243.

Other selected sources

102, 192, 277, 318, 350, 458, 460, 551, 668, 684, 762.

Authors

• I. Soerianegara (general part),

• M.A. Rifai (general part),

• A. Martawijaya (properties),

• J. Ilic (wood anatomy)