Shorea (red meranti) (PROSEA)

Plant Resources of South-East Asia
Introduction

Shorea Roxb. ex Gaertner f. (red meranti)

Protologue: Fruct. 3: 47 (1805).

Family: Dipterocarpaceae

Chromosome number: x= 7; 2n= 14 for the majority of species, S. ovalis: 2n= 28

Trade groups

Light red meranti: lightweight hardwood, e.g. Shorea leprosula Miq., S. ovalis (Korth.) Blume, S. parvifolia Dyer, S. smithiana Sym.

Dark red meranti: lightweight to medium-heavy hardwood, e.g. S. curtisii Dyer ex King, S. macrantha Brandis, S. ovata Dyer ex Brandis, S. pauciflora King, S. platyclados v. Slooten ex Foxw.

Wood of intermediate colour which cannot be grouped satisfactorily within one of the classes mentioned above is usually given the general name red meranti. Apart from the division into light and dark red meranti, the wood of several species is sometimes traded under a distinct name. The most important ones are:

"alan batu" and "alan bunga" for heavy and lightweight timber, respectively, of S. albida,
"belangeran" for timber of S. balangeran,
"kawang jantong" for timber of S. macrophylla,
"melantai" for timber of S. macroptera and
"meranti bakau" for timber of S. uliginosa.

Heavier grades of some species may be traded as red balau (e.g. S. albida, S. balangeran and S. inaequilateralis); hence, the distinction between the trade groups red meranti and red balau is not sharp.

Vernacular names

Light red meranti:

Brunei: meraka bunga
Indonesia: meranti merah muda, seraya merah, meranti bunga
Malaysia: (light) red seraya (Sabah), lup (Iban, Sarawak)
Philippines: (light) red lauan, almon, mayapis
Thailand: saya, saya-khao.

Dark red meranti:

Brunei: meraka
Indonesia: meranti merah tua, meranti ketuko
Malaysia: (dark) red seraya (Sabah), perawan (Iban, Sarawak), obar suluk (Sabah)
Philippines: (dark) red lauan, tangile, tiaong
Thailand: saya, saya-daeng.

Origin and geographic distribution

Shorea consists of about 194 species, 163 of which occur in Malesia. The genus is distributed from Sri Lanka and India through Indo-China towards Malesia. Within Malesia the species occur eastward to the Moluccas. The genus is absent from the Lesser Sunda Islands but fossil wood has been recorded for Timor.

The 70 species belonging to the red meranti group of Shorea occur from southern Thailand towards Borneo, the Philippines and the Moluccas. The greatest diversity occurs in Borneo (62 species), followed by Sumatra (23 species), Peninsular Malaysia (19 species), the Philippines (5 species) and the Moluccas (1 species). Red meranti is absent from Sulawesi.

Uses

Shorea is economically the most important timber genus in the humid Asian tropics.

Red meranti is the most common general utility timber of western Malesia. Due to its non-siliceous nature it is generally easy to work. However, because the wood is not durable (both fungi and insects attack it rapidly), it should not be used in contact with the ground or in exposed conditions, unless properly treated. The general use of the timber is for light constructional work and especially for plywood and veneer. Because of its relatively short fibre length, no high-quality pulp can be produced from the wood.

Light red meranti, being somewhat less heavy than dark red meranti, is used for light-duty flooring, fittings, panelling, ceiling, shelving, interior partitions, joinery, low-grade decking and boat planking, concrete shuttering, musical instruments (organ pipes), coffins, boxes, toys, turnery and matches. Both hardboard and particle board of satisfactory quality can be obtained. Light red meranti is widely used for plywood, both as face and core veneer.

Dark red meranti is used largely for the same purposes as light red meranti but the heavier grades are suitable for medium or even heavy constructional work. Apart from the purposes mentioned above, dark red meranti is used for door and window frames, beams, joists, rafters, utility flooring, vehicle bodies, weatherboarding and boat building. Selective species can be quite decorative and are used for carving, turnery, cabinets, panelling and flooring.

Several species of red meranti yield an opaque, yellow dammar which is of low grade but often available in large quantities and sold as "damar daging" or "damar batu". It is mainly used locally for torches, sometimes also in plasters, varnishes and lacquers, and as a solution in chloroform or xylene for preserving animal and vegetable specimens for microscopy.

Several Shorea species are important sources of illipe nuts; a name which leads to confusion with the illipe nuts produced by Madhuca spp. (Sapotaceae). The nuts yield a fat similar to cocoa butter which is used in Europe for the manufacture of chocolates and cosmetics and was formerly used in soaps, candles and tallow. Locally the boiled fruits of many species are eaten.

The bark of several species may be peeled off in large slabs to be used for panelling walls of native houses and for the manufacture of baskets and bins. The bark of some species is also used for tanning leather.

Production and international trade

For Indonesia, only export figures for sawn meranti as a whole are available. However, red meranti forms by far the major part of this trade group, the export of which amounted in 1989 to 1.4 million m³, worth US$ 301 million. The production and export of plywood (estimated export value in 1990 3000 million US$), in which red meranti wood contributes the major part, is much more important in Indonesia.

In Peninsular Malaysia the average annual volume of exported sawn red meranti was 802 000 m³ in the period 1981-1991. The export values in 1989 and 1990 were US$ 301 million and US$ 271 million respectively, and in 1992 US$ 210 million. Dark red meranti represented about 75% of these values, light red meranti about 7.5%, the rest being traded under the general trade name "red meranti". In 1992 the price of exported sawn dark red meranti timber was US$ 516/m³, US$ 441/m³ for light red meranti, and US$ 216 for "red meranti". The export of round logs of red meranti from Sabah was 2.6 million m³in 1987, with a value of US$ 282 million; in 1992 the export of logs was 815 000 m³ and of sawn timber 795 000 m³, with a total value of US$ 324 million. Light red meranti represented about 75% of this value.

In the period 1980-1989 the value of exported red meranti, for the major part "red lauan" (S. negrosensis) and "white lauan" (S. contorta), in the Philippines fluctuated from US$ 261 million to US$ 117 million. In 1990 it fell to US$ 11 million because of changes in timber policy. In the course of the 1980s the condition of the export product changed from non-processed to processed wood.

Properties

Red meranti is a light to medium-heavy hardwood. The heartwood varies from pale pinkish or light red-brown to pinkish-red or dark red, or even weathering to dark red-brown; it is distinct from the lighter coloured sapwood. Quarter-sawn surfaces often display an attractive stripe figure. The density varies from 300-860 kg/m³ at 15% moisture content. The grain of the wood is interlocked or wavy, sometimes straight, texture usually coarse but even. The darker and heavier wood (often over 600 kg/m³ at 15% moisture content) is often traded as "dark red meranti", the lighter coloured and lightweight wood (often less than 600 kg/m³) as "light red meranti". However, there is considerable overlap between these groups.

The mechanical and physical properties of this large group of species are widely divergent. At 15% moisture content, the modulus of rupture is 32-92 N/mm², the modulus of elasticity 6550-17 150 N/mm², compression parallel to grain 21-46 N/mm², compression perpendicular to grain 2.5-5 N/mm², shear 2.5-9(-11) N/mm², cleavage 23-61 N/mm radial and 19-75 N/mm tangential, Janka side hardness 510-3960 N and Janka end hardness 1050-4480 N.

The rates of shrinkage are variable, depending on the species, from green to 15% moisture content 1.1-2.6% radial and 3.3-5.4% tangential and from green to oven dry 1.5-4.0% radial and 3.5-8.5% tangential. Red meranti dries usually fairly rapid without drying defects or degrade. Air seasoning of 15 mm and 40 mm thick boards takes 2-2.5 months and 4.5-5 months, respectively. Weighting is recommended to prevent warping. In Malaysia kiln schedule F is used; 25 mm thick boards can be kiln dried from 50% to 10% moisture content in 6-7 days, 50 mm thick boards in about 20 days. At the end of drying, the moisture content of boards may vary considerably, due to different drying properties of wood from different species. This may necessitate modified kiln schedules.

Red meranti timber is easy to resaw, to cross cut, to plane, to bore and to turn. The planed and turned surface is smooth, the bored surface may, however, be rough in some species (e.g. S. hemsleyana and S. parvifolia). The presence of interlocked grain may give rise to "picking up" of grain in quarter-sawn material. Occasionally, resin deposits may cause difficulties during sawing. The nailing properties are usually rated as good, but some species have poor resistance to splitting (e.g. S. hemsleyana). The wood sands to a smooth surface and receives stains and polishes well.

Red meranti is highly preferred and widely used for plywood production. It is easy to peel, although defects such as brittle heart, hollow core, worm holes and end splits may reduce the yield. Veneers dry without defects, and the gluability is good. The wood can be made into hardboard of good quality, both by wet and dry processes. When defibred at 170ÔÇ∞C, the wood can be made into hardboard of good quality without chemical treatment and into superhardboard by oil tempering. Experimental particle boards made with 8% resin and 1% wax and of density above 630 kg/m³ showed properties exceeding those stipulated in the British standard.

Light red meranti is classified as non-durable. Graveyard tests conducted in Malaysia indicated that the average service life in contact with the ground is less than 2 years. Dark red meranti can be moderately durable with an average service life ranging from 2.0 years (e.g. S. singkawang) to 4.2 years (e.g. S. platyclados and S. uliginosa). The sapwood is susceptible to dry-wood termite attack; the termites may subsequently affect the heartwood. The wood is usually resistant to fungal and powder-post beetle attack, and it is susceptible to attack by marine borers (particularly light red meranti), but sometimes fairly resistant (e.g. S. curtisii). The wood is generally resistant to preservative impregnation. Using the open tank treatment and an equal mixture of creosote and diesel fuel, an absorption of 24-60 kg/m³ can be obtained and 57-192 kg/m³ when using the full-cell pressure treatment. However, some species absorb preservatives more easily (e.g. S. parvifolia with an average absorption of 312 kg/m³ using the full-cell pressure treatment).

Red meranti wood consists of 50-56% cellulose, 31-37% lignin, 8-24% pentosan, up to 0.9% ash (S. smithiana), and up to 0.3% silica (S. leprosula). The solubility is 0.6-5.4% in alcohol-benzene and 2.3% in hot water.

The dammar consists of volatile oil, resins and bitter substances. It is yellowish-white, semi-transparent, and has varying degrees of hardness. It is insoluble in water, but soluble in alcohol, chloroform and ether.

Description

Medium-sized to very large trees up to 60(-70) m tall; bole straight, cylindrical, free of branches for 10-30(-42) m and with a diameter of 70-180(-255) cm; buttresses usually prominent, up to 3(-5) m tall; bark surface smooth, prominently V-section fissured or becoming flaky, sometimes scaly, grey or brown; outer bark rather thick, brown, inner bark rather thick, reddish, pink or orange, exuding an olive brown to reddish resin which becomes opaque yellow after exposure; mature crown hemispherical or dome-shaped, sympodial.
Leaves alternate, simple, entire, glabrous, pinnately veined with scalariform tertiary venation, often glaucous on the lower surface; stipules and bracts usually large, persistent or fugaceous.
Inflorescences terminal or axillary, paniculate.
Flowers secund or distichous, usually rather crowded, bisexual, 5-merous, actinomorphic, scented; calyx lobes free, hirsute; petals connate at base, lanceolate, cream suffused with pink, the outer surface hirsute; stamens usually 15, sometimes up to 50(-70), the anthers with 4 pollen sacs, linear-oblong to subglobose, with short to long but glabrous appendages; ovary with or without a stylopodium, style usually longer than the ovary.
Fruit usually shortly stalked, with the outer 3 calyx lobes usually much elongated, these thickened and saccate at base; nut 1-seeded, free from the calyx, subglobose to ovate, sharply pointed.
Seedling with epigeal germination; pericarp splitting irregularly; cotyledons usually green; first two leaves opposite, subsequent leaves arranged spirally, often larger than those of mature trees.

Wood anatomy

Macroscopic characters

Heartwood light red (varying to almost white), light pinkish-brown (light red meranti), dark pinkish-brown or dark red and weathering to dark red-brown (dark red meranti), usually distinctly demarcated from the lighter sapwood (often with a grey tinge).
Grain usually interlocked and wavy.
Texture rather coarse but even; planed radial surface often with a prominent stripe figure (especially dark red meranti), quarter-sawn surface sometimes with attractive speckles (light red meranti), planed surface fairly lustrous.
Growth rings usually indistinct or absent (sometimes moderately distinct in light red meranti).
Vessels mostly solitary, less often in oblique or radial pairs or multiples (up to 4 vessels in a series), tyloses generally present but not abundant, vessels visible to the naked eye.
Parenchyma sparse to moderately abundant, distinct or indistinct with a lens.
Rays usually distinct to the naked eye on cross-section, conspicuous (light red meranti) or fairly conspicuous (dark red meranti) on the radial surface.
Ripple marks usually absent or indefinite, but occasionally distinct.
Resin canals generally smaller than vessels, barely distinct to the naked eye, in long concentric lines, filled with white or yellowish-white resin.

Microscopic characters

Growth rings usually absent or indistinct.
Vessels diffuse, 3-10/mm², mostly solitary but also in oblique or radial multiples of 2-4 (15-20%), sometimes with a tendency to form diagonal lines, round to oval, with a tangential diameter of 160-330 μm; perforations simple; intervessel pits alternate, vestured, with an average diameter of 8μm; vessel-ray pits simple, large and round to gash-like; helical thickenings absent.
Fibres 900-1600μm long, 16-25 μm in diameter, usually non-septate but occasionally septate (e.g. S. acuminata, S. beccariana, S. ovata, S. rugosa, S. singkawang), walls 3-6 μm thick (but c. 8μm in S. balangeran and S. inaequilateralis), pits indistinctly or minutely bordered, lumen sometimes filled with colourless, solid substances (e.g. in S. pinanga, S. selanica).
Parenchyma variable in amount (scarce to abundant, depending on the species), of two types, paratracheal and apotracheal; paratracheal parenchyma restricted to narrow, often incomplete sheaths to the vessels (narrowly vasicentric), sometimes distinctly aliform or locally confluent; apotracheal parenchyma diffuse and diffuse-in-aggregates or appearing as discontinuous, narrow, irregular tangential bands enclosing resin canals, sometimes as discontinuous lines of 1 to a few cells wide; parenchyma strands irregularly storied in some specimens.
Rays 4-5(-12)/mm, usually multiseriate, mostly 3-4 cells wide (average width 60μm), up to 40 cells high, composed of procumbent central cells and 2-4 rows of upright and square marginal cells (Kribs type heterogeneous II) or with a single row of square marginal cells (Kribs type heterogeneous III). Prismatic crystals scarce to moderately frequent in normal parenchymatic cells and/or in enlarged idioblasts, sometimes crystals absent (e.g. S. argentifolia, S. curtisii, S. dasyphylla, S. palosapis, S. negrosensis).
Resin canals in tangential rows and in elongated groups embedded in parenchyma, their number varying greatly between the species, average diameter 40-80 μm, but sometimes up to 200 μm (e.g. S. ovata, S. teysmanniana), filled with white resin; radial canals occasionally present in S. leprosula.

Species studied: S. acuminata, S. argentifolia, S. balangeran, S. beccariana, S. curtisii, S. dasyphylla, S. ferruginea, S. hemsleyana, S. inaequilateralis, S. johorensis, S. lepidota, S. leprosula, S. macrantha, S. macroptera, S. negrosensis, S. ovalis, S. ovata, S. pachyphylla, S. palembanica, S. palosapis, S. parvifolia, S. pauciflora, S. pinanga, S. platycarpa, S. platyclados, S. rugosa, S. scaberrima, S. scabrida, S. selanica, S. singkawang, S. teysmanniana.

Red meranti differs from red balau by its lower density and usually less numerous rays. This distinction is, however, not sharp. White and yellow meranti differ from red meranti by their colour (whitish-brown and yellowish-brown), generally more numerous vessels, and more contrasting, yellowish parenchyma and rays.

Growth and development

Red meranti seedlings often grow faster on sunny than on shaded sites, but many seedlings suffer severe damage from prolonged exposure to full sunlight. Full sunlight usually causes the soil temperature near the seedlings to rise, and this inactivates their mycorrhizae. Seedlings usually survive best in intermittent sunlight. Survival and growth in heavy shade varies between species; S. curtisii is reported to be shade-tolerant, but S. macroptera less so.

Mycorrhizae are essential for optimal growth. For instance, nursery-grown seedlings of S. stenoptera showed a considerable increase in growth after inoculation with mycorrhiza of Scleroderma sp. and the best results for S. pinanga were obtained by inoculation with Russula sp. Mycorrhizal infection of seedlings in a selectively logged-over forest in Peninsular Malaysia was high: 78% for S. leprosula and 86% for S. curtisii.

Growth rates differ between species. In 40 years red meranti trees may reach a diameter of 48 cm (S. curtisii), but sometimes up to 80 cm (S. scaberrima, S. leprosula) or exceptionally even up to 105 cm (S. parvifolia). Fast-growing species are selected for multiplication in nurseries and for planting, but fast-growing trees may develop brittle heart. In plantations in West Java mean annual height increment of S. leprosula is 1-1.3 m, and mean annual diameter increment 1.9-2.0 cm. S. johorensis grows more slowly; at 3 years seedlings reach an average height of 5 m when grown under Calliandra ; plantation trees of S. johorensis increase about 1 m/year in length and about 1 cm/year in diameter. In some species initial seedling growth is slow (e.g. seedlings of S. curtisii reach an average height of only 15 cm after 1 year.)

Flowering generally starts when the tree crown reaches the canopy storey, which may be as soon as 10-15 years after germination for solitary specimens of fast-growing species. Trees of S. pinanga planted in Malaysia flowered and fruited after only 6 years when growth was stimulated by the use of fertilizers. Most dipterocarp species flower gregariously at intervals of 2-5 years. Closely related species may differ in flowering periodicity. In Peninsular Malaysia S. leprosula flowers on average every 2 years, S. parvifolia once in 3 years in plantations but every 5 years in nature. For the hill species S. curtisii and S. platyclados the flowering interval is also about 5 years. For several red meranti-producing species it was found that up to 50% of the stands flowered in years of gregarious flowering. The pollinators include thrips, psyllid bugs and honey bees (Apis spp.). Research during gregarious flowering of red meranti showed that there is only a slight overlap in the peak blooming period of different species, but that fruits ripen simultaneously. Fruit production in the forest may be abundant in so-called "mast years". S. contorta trees in the Philippines produce up to 185 000 fruits per fruiting season. Almost 90% of the fruits fall within 20 m of the mother tree. Under normal wind conditions and in a closed forest the dispersal of viable fruits is within 30 m. This may explain the clustering of trees in the forest. Clustered trees of S. leprosula in Malaysia were found to produce more fruits than isolated trees.

Cross-fertilization may occur between certain species, but is generally rare. Natural hybridization is reported to occur between S. splendida and S. stenoptera. Most dipterocarps have been found to be predominantly outbreeders, with high within-population variability. S. ovalis, however, is pseudogamous and self-compatible. Apomixis is found in several species, e.g. in S. ovalis, S. macroptera and S. parvifolia, where multiple seedlings occur.

Other botanical information

At infrageneric level the species may be classified by anatomical features of the wood and bark. The division of the genus Shorea into 4 major timber groups (red meranti, white meranti, yellow meranti and balau) coincides in broad outline with the division of the genus into botanical sections. Timber trees of the red meranti group belong to the sections Brachypterae Heim, Mutica Brandis, Ovalis P. Ashton, Pachycarpae Heim and Rubella P. Ashton. The distinction between red meranti and red balau is not sharp. Several species may yield both types of timber depending on the denisty (e.g. S. albida, S. balangeran, S. inaequilateralis, S. kunstleri). Their classification in either one of the groups, as presented here, is debatable. All these species are treated as red meranti, except for S. kunstleri.

S. contorta belongs to the section Pentacme (A.DC.) P. Ashton but is classified either as a light red meranti or as a white meranti, or even as a white lauan, the latter being the timber name for species of the genus Parashorea. The red meranti group is the most heterogeneous timber group within the genus. Species yielding light or dark red meranti are somewhat evenly distributed amongst the sections mentioned above.

Ecology

Shorea species are confined to tropical climates with a mean annual rainfall exceeding 1600 mm and with a dry season of less than 6 months. Most species occur below 1000 m altitude. Species and individuals are most numerous on deep, well-drained yellow or red soils in the lowland. Most species are restricted to a single vegetation type or substratum. Some are common to gregarious in a certain habitat. A few species are confined to certain edaphic habitats such as heath forest (e.g. S. coriacea, S. venulosa), on sandy soils (e.g. S. curtisii, S. flemmichii, S. rugosa, S. scaberrima), and in peat swamps (e.g. S. albida, S. balangeran, S. inaequilateralis, S. macrantha, S. pachyphylla, S. platycarpa, S. teysmanniana, S. uliginosa).

Propagation and planting

Until recently Shorea species were never planted. The only method for propagation was by seed, but without infection by suitable ectomycorrhizal fungi, attempts to grow seedlings failed. The wildling collection method for dipterocarp seedlings has been improved and naturally infected seedlings have been collected and planted under a vegetation producing light shade.

Red meranti is still propagated by seed. It is recommended to start seed collecting as soon as the fruit-wings begin to turn brown. The best time to harvest S. pinanga seeds is 5 months after anthesis. The seeds soon lose viability and can be stored for comparatively short periods only. Seeds of S. almon stored at 40% moisture content in ventilated containers at 16 °C declined in viability to 20% within 14 days; storage at 21 °C gave a similar result. The maximum storage period for seeds of S. parvifolia is also 2 weeks. However, seeds of S. platyclados can be stored for 50-60 days. In general, the optimum temperature for storage of seeds is 22-28 °C. Viability can be prolonged by storing in sealed wooden boxes or by coating the seeds with wax. Seeds of S. pinanga stored in this way showed a viability of 46-63% after 4 weeks, whereas seeds in open containers lost their viability completely. The germination medium recommended for red lauan (S. negrosensis) in the Philippines is sand or an equal mixture of sand and ordinary garden soil.

Application of fertilizers may improve growth of seedlings. In the Philippines, seedlings of S. palosapis responded best in growth after 2 consecutive applications of 1 g and 2 g NPK fertilizer per seedling; for S. contorta seedlings fertilizing with 2 g NPK per plant is recommended.

Nowadays, methods of vegetative propagation are fairly commonly practised. Stem cuttings can be used, but with varying rates of success. Single-node cuttings from seedlings of S. macrophylla 8-15- month-old root easily under continuous mist, with or without application of auxins, but only up to 6% of stem cuttings of S. acuminata, treated with growth regulators, rooted in experiments in Malaysia. For S. leprosula the results of propagation by cuttings diverge widely. Good results were obtained by using stem cuttings comprising 1 node and 10 cm of internode below the bud and taken from 1-year-old seedlings; 65% of the stem cuttings rooted without the use of growth regulators. In other experiments only 6% of stem cuttings of S. leprosula rooted, and growth regulators did not improve the result. However, treating the roots of red meranti seedlings with growth regulators may increase survival and height growth.

In the Philippines, S. contorta has been propagated successfully by air layering and grafting, but the success rate was low (20% and 5%, respectively). Experiments with in vitro culture showed that leaf explants of young S. curtisii plants formed callus when they contained a part of the midrib and when they were taken from the lower half of a leaf; a full strength Murashige and Skoog medium was used. Terminal and axillary buds grow best on a half-strength medium.

For enrichment planting with 4-month-old red meranti seedlings, strips 1 m wide and with a planting distance of 3 m are recommended. For plantations, the best planting distance is probably 4 m × 4 m.

Silviculture and management

Natural regeneration and growth of planted seedlings in logged-over or planted forest is generally satisfactory, but canopy manipulation is often needed for optimal growth of seedlings and saplings. It is advisable to remove overhead shade within 3-6 months after planting S. parvifolia seedlings in a forest. Sometimes, weeding is necessary. Regeneration of S. curtisii in Peninsular Malaysia is often hampered by forest undergrowth of bertam (Eugeissona tristis Griffith), and may be increased considerably by control of this stemless palm. In plantations, overstorey light should be increased by thinning after the crowns have developed sufficiently (more than 50% closure). For moderately fast growing species like S. johorensis, this can begin in plantations about 30-year-old.

Diseases and pests

Fusarium fungi may kill seedlings (e.g. of S. leprosula and S. pinanga). Seeds and seedlings (e.g. of S. pinanga) are occasionally attacked by another fungus, Cylindrocarpon destructans. Weevils like Alcidodes dipterocarpi and Nanophyes shoreae are major pests of seeds, locally damaging up to 85% of the seeds. Other seed-attacking insects include Microlepidoptera (small moths) of the families Pyralidae and Totricidae, and beetles of the family Scolytidae. Terrestrial vertebrates, particularly boars and squirrels feed on fallen seeds and are the major cause of seed mortality. Ants and termites also feed on fallen seed. Some caterpillars eat seedlings, although seedling predation is generally low.

Harvesting

Red meranti logs float in water and can be transported by river. This is commonly practised in Borneo.

Yield

In forest in Kalimantan the standing volume of trees over 60 cm in diameter is usually 60-90 m³/ha, and 110 m³/ha is not exceptional. Three-quarters of these trees belong to meranti (of which red meranti is dominant). The average yield of red meranti wood is 10-12 m³/tree.

Genetic resources

A timber trade group including a large number of species blurs information on individual species threatened with extinction and such species may therefore receive insufficient protection. This is surely the case with red meranti. Some species are widespread and gregarious (e.g. S. parvifolia) and are not seriously threatened by logging, but others are much less common or occur only locally (e.g. S. mecistopteryx) and may easily become endangered. Locally, stands of species have already been considerably depleted because of logging and destruction of habitats, e.g. the peat-swamp forest species S. teysmanniana and S. uliginosa in Peninsular Malaysia. Ex situ conservation is important for endangered and rare species. Large collections of Shorea trees are present in several botanical gardens, e.g. in Bogor (Indonesia) and Kepong (Forest Research Institute Malaysia). These collections can be important sources of seed, although there is growing evidence that such seed may be inferior because of inbreeding depression.

Breeding

No breeding has been done so far. However, improved methods of vegetative propagation have opened new opportunities for the near future. Fast-growing species which propagate comparatively easy may be domesticated for timber production by propagation of superior clones, e.g. S. macrophylla which yields illipe nuts in addition to timber.

Prospects

Species producing red meranti are very promising for the establishment of large-scale plantations. Several species grow fast and yield a good-quality timber. In the past, the absence of successful propagation methods was a major constraint, but since the 1980s much research has been conducted on the propagation and planting of merantis and the results are useful for establishing plantations. When, in addition, appropriate systems of sustainable management of production forest are established and employed, the future of the market for processed red meranti will be promising. However, a reduction of yield and export, and rising prices seem to be unavoidable. Besides, complete preservation of large tracts of lowland forest in different ecological habitats is needed, to ensure the survival of the many less common species and to conserve the genetic variability of others as this is lost in vegetatively propagated stands.

Literature

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Choo, K.T. & Lim. S.C., 1982. Malaysian timbers - dark red meranti. Malaysian Forest Service Trade Leaflet No 69. Malaysian Timber Industry Board, Kuala Lumpur. 14 pp.
Choo, K.T. & Lim, S.C., 1983. Malaysian timbers - light red meranti. Malaysian Forest Service Trade Leaflet No 75. Malaysian Timber Industry Board, Kuala Lumpur. 11 pp.
Durand, P.Y., 1985. Commercial nomenclature of Shorea and Parashorea. Revue Bois et For√™ts des Tropiques 210: 59-66.
Lo, Y.N., 1985. Root initiation of Shorea macrophylla cuttings: effects of node position, growth regulators and misting regime. Forest Ecology and Management 12: 43-52.
Martawijaya, A., Kartasujana, I., Kadir, K. & Prawira, S.A., 1986. Indonesian wood atlas. Vol. 1. Forest Products Research and Development Centre, Bogor. pp. 81-87.
Santoso, E., 1989. The effect of mycorrhiza on the stem diameter and dry weight of dipterocarp seedlings. Buletin Penelitian Hutan 504: 11-22.
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Selection of species

Authors

K.M. Kochummen (general part),
W.C. Wong (properties),
J.M. Fundter (wood anatomy) &
M.S.M. Sosef (selection of species)