Eucalyptus deglupta (PROTA)

From PlantUse English
Jump to: navigation, search
Prota logo orange.gif
Plant Resources of Tropical Africa
Introduction
List of species


General importance Fairytale bookmark gold.svgFairytale bookmark gold.svgFairytale bookmark gold.svgFairytale bookmark gold.svgGood article star.svg
Geographic coverage Africa Fairytale bookmark gold.svgFairytale bookmark gold.svgFairytale bookmark gold.svgFairytale bookmark gold.svgGood article star.svg
Geographic coverage World Fairytale bookmark gold.svgFairytale bookmark gold.svgFairytale bookmark gold.svgFairytale bookmark gold.svgGood article star.svg
Carbohydrate / starch Fairytale bookmark gold.svgGood article star.svgGood article star.svgGood article star.svgGood article star.svg
Timber Fairytale bookmark gold.svgFairytale bookmark gold.svgGood article star.svgGood article star.svgGood article star.svg
Fuel Fairytale bookmark gold.svgFairytale bookmark gold.svgGood article star.svgGood article star.svgGood article star.svg
Ornamental Fairytale bookmark gold.svgFairytale bookmark gold.svgFairytale bookmark gold.svgGood article star.svgGood article star.svg
Auxiliary plant Fairytale bookmark gold.svgFairytale bookmark gold.svgGood article star.svgGood article star.svgGood article star.svg
Fibre Fairytale bookmark gold.svgFairytale bookmark gold.svgFairytale bookmark gold.svgGood article star.svgGood article star.svg
Climate change Fairytale bookmark gold.svgFairytale bookmark gold.svgGood article star.svgGood article star.svgGood article star.svg


Eucalyptus deglupta Blume


Protologue: Mus. Bot. 1(6): 83 (1850).
Family: Myrtaceae
Chromosome number: 2n = 22

Synonyms

  • Eucalyptus multiflora Rich. ex A.Gray (1854),
  • Eucalyptus naudiniana F.Muell. (1886),
  • Eucalyptus schlechteri Diels (1922).

Vernacular names

  • Mindanao gum, deglupta, rainbow eucalyptus, rainbow bark, rainbow gum (En).
  • Eucalyptus arc-en-ciel, gommier arc-en-ciel, gommier de Mindanao (Fr).
  • Goma de Mindanao, goma do arco-íris (Po).

Origin and geographic distribution

Eucalyptus deglupta has a natural distribution from Sulawesi (Indonesia) and Mindanao (Philippines) eastward to New Britain (Papua New Guinea). It is one of the few Eucalyptus species not occurring in Australia. It is widely planted throughout the humid tropics, where it is one of the most important eucalypts.

Uses

Eucalyptus deglupta is a major plantation tree for pulp production; both the wood and bark are good sources of pulp. The wood is valuable timber (trade name: kamarere), suitable for light and heavy construction, flooring, furniture, joinery, moulding, boat building, posts, poles, veneer, plywood, particle board, hardboard and wood-wool board. It is also used as fuelwood and for charcoal making, but is normally considered too valuable for these purposes. Eucalyptus deglupta is widely planted as an ornamental tree because of its attractive bark. The tree is used for land reclamation, reforestation and forest enrichment planting. In Costa Rica it is commonly used as a shade tree in coffee plantations. It is a bee forage.

Production and international trade

In the 1990s the area planted with Eucalyptus deglupta was about 30,000 ha in Indonesia and the Philippines each, and about 10,000 ha in Brazil. Other countries with substantial plantations were Malaysia, Papua New Guinea, Sri Lanka, Fiji, Côte d’Ivoire and Ghana.

Properties

The wood contains 44–51% cellulose, 29–30% lignin, 14–19% pentosan and 0.6–1.2% ash. The ultimate fibres in wood from Côte d’Ivoire are on average 1.0 mm long and 19.5 μm wide, with a lumen width of 12 μm. Pulping with the kraft (sulphate) process gives a strong pulp which can be bleached to a good brightness.

The heartwood is reddish brown, not always distinctly demarcated from the whitish to pink sapwood. The grain is interlocked, texture moderately coarse. The wood has a ribbon-like aspect on quarter-sawn faces, and is lustrous. The density of the wood is 390–810 kg/m³ at 15% moisture content, but young wood is lighter than older wood, and wood from plantations is lighter than that from natural forest. Plantation wood is easy to dry, with little degrade, but forest wood may collapse. The rates of shrinkage from green to 12% moisture content are 1.8–2.4% radial and 3.4–7.0% tangential. At 12% moisture content, the modulus of rupture is 67–106 N/mm², modulus of elasticity 8000–14,075 N/mm², compression parallel to grain 39–70 N/mm² and shear 7–11 N/mm². The wood works well with hand and machine tools, but it has a slight tendency to tear out in machining and boring and to slight chipping of sharp edges in turning. It finishes well. The wood is not durable; it is liable to termite and Lyctus attack (particularly sapwood), and also to marine borers. Plantation grown wood is significantly easier to impregnate than wood from natural forest. The energy value of the wood is 18,500–21,100 kJ/kg.

Fresh leaves from Nigeria yielded 0.2% essential oil. The major compounds were nerolidol (34.8%), α-pinene (24.7%), β-caryophyllene (5.9%), limonene (4.1%), α-terpineol (4.1%) and p-cymene (3.1%). Fresh leaves from DR Congo yielded 0.15% essential oil, with as main compounds 1,8-cineole (35.7%), cryptone (25.4%), myrtenol (7.4%), β-terpineol (6.3%) and globulol (3.1%). The essential oil has shown activity against a range of bacteria and fungi. The oil content is too low for commercial exploitation.

Description

Evergreen, very large tree up to 60(–80) m tall; bole generally of good form, 50–75% of the tree height, up to 200(–300) cm in diameter, sometimes with buttresses 3–4 m high; bark smooth, yellow, brown and purple, but green after flaking; crown conical in young trees, spreading in older ones; twigs 4-sided, often with 4 longitudinal wings. Leaves opposite, subopposite or alternate, simple and entire, held almost horizontal on branches; stipules absent; petiole 1–1.5 cm long; blade ovate to ovate-lanceolate, 7–15(–20) cm × 4–7.5(–10) cm, apex rounded to acute or slightly acuminate, glabrous, lower surface paler than upper surface, pinnately veined. Inflorescence an axial or terminal, condensed and reduced, umbel-like dichasium (‘conflorescence’), umbels 3–7-flowered; peduncle up to 12 mm long, angular. Flowers bisexual, regular; pedicel c. 5 mm long; flower buds globular to nearly club-shaped, 2–4 mm × 2–5 mm, apiculate, divided into a conical hypanthium (lower part) 2–2.5 mm long, and a hemispherical or conical operculum (upper part) shed at anthesis; stamens numerous; ovary inferior. Fruit a thin-walled, ovoid to club-shaped or globose capsule 3–5 mm × 3–5 mm, enclosed in a woody hypanthium, opening with 3–4 small, exserted valves, many-seeded. Seeds minute, brown, flattened, with a small terminal wing. Seedling with epigeal germination.

Other botanical information

Eucalyptus comprises about 800 species, endemic to Australia, except for about 10 species in the eastern part of South-East Asia. Many Eucalyptus species are cultivated outside their natural distribution area, in tropical, subtropical and temperate regions, because of their rapid growth and adaptation to a wide range of ecological conditions. Eucalyptus is divided into several subgenera (7–10, depending on the author), which are subdivided into many sections and series. The results of phylogenetic studies within Eucalyptus suggest that the genus is polyphyletic, hence not of a single evolutionary origin, and consequently it has been proposed to divide the genus into several distinct genera. This has not yet been done, mainly because of the nomenclatural whirlpool this would bring about. Eucalyptus species hybridize easily, which adds to the taxonomic complexity.

Growth and development

Eucalyptus deglupta grows very fast, being capable of annual growth rates of 2–3 m in height and 2–3 cm in diameter during the first 10 years. In Congo, for instance, trees 8.5 years old were on average 20 m tall, with a diameter of 13.5 cm. Shoot growth of young Eucalyptus deglupta appears to be continuous, provided soil moisture is adequate. Young trees have a conical crown with a definite leader and almost horizontal branches. As the tree ages, branches curve up at the ends and the leader becomes less dominant. In time the tree acquires a spreading, flat topped crown.

Flowering may occur within the first year but more often it takes place after 2 years and annually thereafter. Flowering can occur in all months of the year depending on locality. Fruiting may start as early as 1.5 years after planting, but more commonly after 3–4 years. Fruits ripen in 4–6 month, after which seeds are released rapidly over a few days. Seed production is often profuse. Dispersal is mainly by water. Eucalyptus deglupta does not regenerate from lignotubers. This means that mature trees are sensitive to intense fires, and that coppice harvests are usually not possible after the first harvest.

Ecology

Eucalyptus deglupta is the only Eucalyptus species adapted to lowland and lower montane rain-forest habitats. It grows from sea-level up to 2500 m altitude in areas with a mean annual temperature of 20–32°C, a mean maximum temperature of the warmest month of 24–33°C, and a mean minimum temperature of the coldest month of 16–26°C, an evenly distributed average annual rainfall of (1200–)2000–5000 mm, and a dry season of 0–1 months. Eucalyptus deglupta may grow in cooler environments but does not tolerate frost. It requires full overhead light for development and dense stands are commonly found along rivers where it has colonized newly formed sand banks. Eucalyptus deglupta is also found on sites that have been cleared or disturbed in some way, e.g. by landslides, volcanic eruptions, or shifting cultivation. It is a rapid colonizer of such sites. In time, however, other species colonize and form a dense understorey which prevents subsequent regeneration of Eucalyptus deglupta. Eucalyptus deglupta prefers non-stagnant river flats with adequate soil moisture and grows best on deep, moderately fertile sandy loams but also on volcanic ash, pumice and gravel soils. In Congo it is recorded to grow better on heavy clay soils than on sandy soils. The species does not withstand prolonged flooding, however. It is highly sensitive to fire, due to its very thin bark.

Propagation and planting

Eucalyptus deglupta is easily propagated from seed. The 1000-seed weight is 0.1–0.5 g. Seed can be obtained by collecting the fruits when they are greenish brown and drying them in the sun for 2–3 days. Seed can be stored 1–2 years under cool, dry and airtight conditions. The optimum temperature for germination is 32–35°C, and no pre-treatment is necessary. The seeds have a germination rate of 50–60% and one gram of dry seeds produces 1000–2000 seedlings. Germination takes 4–20 days and seedlings in nurseries can be planted out when they are 3–4 months old and 25–30 cm tall. In Gabon seedlings are planted at spacings of 4 m × 3 m on clay soils, and 4 m × 4 m on sandy soils. In pulpwood plantations in Congo a spacing of 2.8 m × 2.8 m is used.

Vegetative propagation with branch cuttings is easier than with other Eucalyptus species, and even cuttings from crowns of old trees can be used. The cuttings will root when their base is immersed in water alone. Plants 25–30 cm tall normally develop from cuttings within 6 weeks in tropical environments. Methods of in-vitro propagation have also been developed.

Management

After seedlings have been planted out in Gabon, weed control measures are needed until the plants are about 2 years old and the crowns have closed. Plantations for sawlogs require thinning. Eucalyptus deglupta does not coppice well after cutting and must be replanted.

Diseases and pests

Seedlings in nurseries are susceptible to damping-off caused by Rhizoctonia solani, which can be controlled by sterilization of the germination medium or application of fungicides. Eucalyptus deglupta is hardly attacked by leaf spot diseases, making it very suitable for the lowland tropics. Heart rot is sometimes found in older trees but is unlikely to be a problem in trees grown on a short (e.g. 10 years) rotation. Field observations suggest that heart rot is more common in trees growing on less well drained sites. Both in natural stands and in plantations termites are the most serious pest.

Harvesting

Trees in pulpwood plantations are usually harvested 5–7(–12) years after planting, while plantations for sawlogs are harvested when they are 16–25 years old. Buttresses are frequent on trees growing on river alluviums and non stable soils in the natural area of distribution of the species; to harvest the logs, scaffolding has to be built so the stem can be sawn through above the buttresses.

Yield

Eucalyptus deglupta is one of the fastest growing hardwood trees in the world. In pulpwood plantations yields of 200–300 m³/ha at 10–12 years of age are commonly achieved. In plantations in Gabon the target bole diameter of 30 cm is attained when the trees are 8–10 years old, with a standing volume of 300–350 m³/ha.

Genetic resources

Provenance trials in Papua New Guinea using seed collected across the whole natural distribution range of Eucalyptus deglupta show variability in morphology, growth, and susceptibility to pests. Mindanao, Sulawesi and New Britain provenances appear to be better than the mainland Papua New Guinea ones. The trials included most of the mainland Papua New Guinea provenances of Eucalyptus deglupta but not many from Indonesia or the Philippines. In view of the variability already evident, it is highly desirable that the remaining provenances be tested as soon as possible, especially as some may be threatened by clearing for agriculture. The viability of seed material stored at –15°C is recorded to fall sharply after 7 years.

Breeding

The variability within Eucalyptus deglupta offers potential for selection. Breeding work is in progress e.g. in Costa Rica and Indonesia.

Prospects

Eucalyptus deglupta shows great promise for reforestation and afforestation in wet tropical lowland areas without a pronounced dry period. It has particularly high potential for industrial pulp production because of its easy vegetative propagation, rapid growth and excellent wood properties. Disadvantages of the species are its susceptibility to fire and the fact that it does not coppice well. Where heart rot and insect pests have been reported they appear to be only locally significant. Further, because of the genetic variability of Eucalyptus deglupta and the short delay till its reproductive period, there are good prospects for tree improvement.

Major references

  • Chudnoff, M., 1980. Tropical timbers of the world. USDA Forest Service, Agricultural Handbook No 607, Washington D.C., United States. 826 pp.
  • Eldridge, K., Davidson, J., Harwood, C. & van Wijk, G., 1993. Eucalypt domestication and breeding. Clarendon Press, Oxford, United Kingdom. xix + 288 pp.
  • Jacobs, M.R., 1981. Eucalypts for planting. 2nd Edition. FAO Forestry Series No 11. Food and Agriculture Organization of the United Nations, Rome, Italy. 677 pp.
  • Lamb, D., Johns, R.J., Keating, W.G., Ilic, J. & Jongkind, C.C.H., 1993. Eucalyptus L’Hér. In: Soerianegara, I. & Lemmens, R.H.M.J. (Editors). Plant Resources of South-East Asia No 5(1). Timber trees: Major commercial timbers. Pudoc Scientific Publishers, Wageningen, Netherlands. pp. 200–211.
  • Lamprecht, H., 1989. Silviculture in the tropics: tropical forest ecosystems and their tree species, possibilities and methods for their long-term utilization. Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH, Eschborn, Germany. 296 pp.
  • Orwa, C., Mutua, A., Kindt, R., Jamnadass, R. & Simons, A., 2009. Agroforestree database: a tree reference and selection guide. Version 4.0. [Internet] World Agroforestry Centre (ICRAF), Nairobi, Kenya. http://www.worldagroforestry.org/ resources/databases/ agroforestree. April 2011.
  • Scott, A.J., 1993. Myrtacées. In: Bosser, J., Cadet, T., Guého, J. & Marais, W. (Editors). Flore des Mascareignes. Familles 90–106. The Sugar Industry Research Institute, Mauritius, l’Institut Français de Recherche Scientifique pour le Développement en Coopération (ORSTOM), Paris, France & Royal Botanic Gardens, Kew, Richmond, United Kingdom. 70 pp.
  • Webb, D.B., Wood, P.J., Smith, J.P. & Henman, G.S., 1984. A guide to species selection for tropical and sub-tropical plantations. 2nd Edition. Tropical Forestry Papers No 15. Commonwealth Forestry Institute, University of Oxford, United Kingdom. 256 pp.

Other references

  • Bachir, O. & Abdellah, B., 2006. Chromosome numbers of the 59 species of Eucalyptus l’Herit (Myrtaceae). Caryologia 59(3): 207–212.
  • Bégué, L., 1963. Les Eucalyptus au sud du Sahara. Bois et Forêts des Tropiques 91: 11–22.
  • Cimanga, K., Apers, S., De Bruyne, T., Van Miert, S., Hermans, N., Totté, J., Pieters, L. & Vlietinck, A.J., 2002. Chemical composition and antifungal activity of essential oils of some aromatic medicinal plants growing in the Democratic Republic of Congo. Journal of Essential Oil Research 14: 382–387.
  • Cimanga, K., Kambu, K., Tona, L., Aspers, S., De Bruyne, T., Hermans, N., Totté, J., Pieters, L. & Vlietinck, A.J., 2002. Correlation between chemical composition and antibacterial activity of essential oils of some aromatic medicinal plants growing in the Democratic Republic of Congo. Journal of Ethnopharmacology 79: 213–220.
  • Coppen, J.J.W., 2002. Eucalyptus: the genus Eucalyptus. Medicinal and aromatic plants - industrial profiles, vol. 22. Taylor & Francis, London, United Kingdom. 450 pp.
  • Doat, J. & Valette, J.C., 1980. L’inflammabilité de quelques bois tropicaux. Bois et Forêts des Tropiques 194: 43–55.
  • FAO, 1974. Tree planting practices in African savannas. FAO Forestry Development Paper No 19. FAO, Rome, Italy. 185 pp.
  • Goudet, J.P., 1975. Plantations expérimentales d’espèces papetières en Côte d’Ivoire. Bois et Forêts des Tropiques 159: 3–27.
  • Goudet, J.P., 1980. Plantations expérimentales d’espèces ligneuses a croissance rapide en République Gabonaise. Bois et Forêts des Tropiques 192: 35–60.
  • Leakey, R.R.B., Mesén, J.F., Tchoundjeu, Z., Longman, K.A., Dick, J.M., Newton, A., Matin, A., Grace, J., Munro, R.C. & Muthoka, P.N., 1990. Low-technology techniques for the vegetative propagation of tropical trees. Commonwealth Forestry Review 69(3): 247–257.
  • Nicolle, D., 2006. A classification and census of regenerative strategies in the eucalypts (Angophora, Corymbia and Eucalyptus – Myrtaceae), with special reference to the obligate seeders. Australian Journal of Botany 54(4): 391–407.
  • Oyedeji, A.O., Ekundayo, O., Olawore, O.N., Adeniyi, B.A. & Koenig, W.A., 1999. Antimicrobial activity of the essential oils of five Eucalyptus species growing in Nigeria. Fitoterapia 70(5): 526–528.
  • Oyedeji, A.O., Olawore, O.N., Ekundayo, O. & Koenig, W.A., 1999. Volatile leaf oil constituents of three Eucalyptus species from Nigeria. Flavour and Fragrance Journal 14(4): 241–244.
  • Raoufou, R., Kouami, K. & Koffi, A., 2011. Woody plant species used in urban forestry in West Africa: case study in Lomé, capital town of Togo. Journal of Horticulture and Forestry 3(1): 21–31.
  • Schaller, M., Schroth, G., Beer, J. & Jiménez, F., 2003. Species and site characteristics that permit the association of fast-growing trees with crops: the case of Eucalyptus deglupta as coffee shade in Costa Rica. Forest Ecology and Management 175(1–3): 205–215.
  • van Oijen, M., Dauzat, J., Harmand, J.-M., Lawson, G. & Vaast, P., 2010. Coffee agroforestry systems in Central America. I. A review of quantitative information on physiological and ecological processes. Agroforestry Systems 80(3): 341–359.
  • Williams, J.E. & Woinarski, J. (Editors), 1997. Eucalypt ecology: individuals to ecosystems. Cambridge University Press, Cambridge, United Kingdom. 430 pp.
  • Zech, W. & Drechsel, P., 1992. Multiple mineral deficiencies in forest plantations in Liberia. Forest Ecology and Management 48(1–2): 121–143.

Sources of illustration

  • Lamb, D., Johns, R.J., Keating, W.G., Ilic, J. & Jongkind, C.C.H., 1993. Eucalyptus L’Hér. In: Soerianegara, I. & Lemmens, R.H.M.J. (Editors). Plant Resources of South-East Asia No 5(1). Timber trees: Major commercial timbers. Pudoc Scientific Publishers, Wageningen, Netherlands. pp. 200–211.

Author(s)

  • M. Brink, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Brink, M., 2011. Eucalyptus deglupta Blume. [Internet] Record from PROTA4U. Brink, M. & Achigan-Dako, E.G. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. <http://www.prota4u.org/search.asp>.

Accessed 3 March 2020.