Afzelia bipindensis (PROTA)

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Plant Resources of Tropical Africa
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Geographic coverage Africa Fairytale bookmark gold.svgFairytale bookmark gold.svgGood article star.svgGood article star.svgGood article star.svg
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distribution in Africa (wild)
1, base of bole; 2, flowering twig; 3, flower; 4, dehisced fruit. Redrawn and adapted by Iskak Syamsudin
flowering branch
flowering branch
flowers
flowers
wood in transverse section
wood in tangential section
wood in radial section

Afzelia bipindensis Harms


Protologue: Bot. Jahrb. Syst. 49: 426 (1913).
Family: Caesalpiniaceae (Leguminosae - Caesalpinioideae)
Chromosome number: 2n = 24

Vernacular names

  • Afzelia (En).
  • Doussié, doussié rouge (Fr).

Origin and geographic distribution

Afzelia bipindensis occurs from southern Nigeria east to western Uganda, and south to DR Congo, northern Zambia and northern Angola.

Uses

Like other Afzelia spp., the wood of Afzelia bipindensis is characterized by an excellent stability with little susceptibility to variations in humidity, small shrinkage rates during drying and a good natural durability. The wood is durable and treatment with preservatives is unnecessary, even for usage in permanent humid conditions or in localities where wood-attacking insects are abundant. This makes it an excellent wood for use in pleasure-crafts, especially for keels, stems and panels, for bridges, as well as interior fittings. For such uses it is sometimes as much in demand as teak. The wood is also valued for joinery and panelling, both interior and exterior, parquet floors, doors, frames, stairs, vehicle bodies, furniture, sporting goods, mine props, musical instruments, railway sleepers, agricultural implements, utensils, tool handles, turnery, fibre board and particle board. It is suitable for decorative sliced veneer. Because of its good resistance to many chemical products and great dimensional stability, it is often preferred to materials like metals and synthetics for vats and precision equipment in industrial applications. The neutral pH of the wood makes it suitable for applications in contact with vulnerable objects such as antiques and old books in libraries. However, it should not be used in contact with textiles under more humid conditions because of the presence of colorants. The wood is also used as firewood and for charcoal production.

In Cameroon the bark exudate is taken to treat stomach-ache. The seed aril is applied to chapped lips.

Production and international trade

The wood of Afzelia bipindensis is commonly traded as ‘doussié’ on the international timber market, although it is often mixed with that of other species such as Afzelia pachyloba Harms. Cameroon is the main exporting country. In 2003 it exported 9900 m³ of sawn doussié wood and 47,750 m³ in 2005. In 2008 the export from Cameroon was 23,300 m³, in which Afzelia bipindensis contributed about 6100 m³. The export of Afzelia bipindensis timber from Congo in 2008 was 1750 m³ of logs and 400 m³ of sawn wood. Gabon exported in the period 1991–1999 on average 6500 m³/year of doussié timber and in 2000–2005 on average 8600 m³/year, in which Afzelia bipindensis had a considerable contribution. In the Central African Republic Afzelia bipindensis is also considered a high-value timber species; in 2004 the export of Afzelia timber (doussié) was 6500 m³.

Properties

The heartwood is pale red-brown to orange-brown or golden brown, becoming red-brown upon long exposure, and distinctly demarcated from the pale yellow, up to 5 cm wide sapwood. The grain is straight to interlocked, texture medium to coarse but even. The wood is slightly glossy and dried wood has a leather-like smell upon planing.

The wood is heavy, with a density of (750–)840–950 kg/m³ at 12% moisture content. Drying usually does not cause problems, without deformation and splitting, but the wood dries slowly. For thick boards (more than 7.5 cm), preliminary air drying under cover is recommended before kiln drying. The shrinkage rates are low, from green to oven dry 2.3–3.9% radial and 3.5–5.4% tangential. Once dry, the wood is very stable in service.

At 12% moisture content, the modulus of rupture is 150–230 N/mm², modulus of elasticity 12,150–17,050 N/mm², compression parallel to grain 67–95 N/mm², shear 7–11 N/mm², cleavage 12–22 N/mm and Chalais-Meudon side hardness 7.9–11.5.

The wood saws easily when good equipment is used; it contains little silica (less than 0.01%) and stellite-tipped saw teeth are not needed for sawing fresh wood. Some logs have gum pockets, which may cause problems in sawing by blunting saw teeth. Tungsten-carbide-tipped cutting tools are recommended in planing and moulding operations. It is advisable to reduce the cutting angle to 15° to avoid rough surfaces when interlocked grain is present. The use of a filler is recommended to obtain smooth surfaces. The nailing and screwing properties are satisfactory, but pre-boring is recommended to avoid splitting. Gluing may be difficult. The wood paints and varnishes well, but wood zones close to the centre of the log may contain anti-oxidant substances that slow down drying of varnish and may cause problems in painting. The steam bending properties are satisfactory, but the presence of gum may cause problems. Sliced veneer of good quality can be produced, but the wood is not used for peeling. The wood has a good reputation for its resistance to acids and alkalines.

The heartwood is durable, with an excellent resistance to fungal, termite and borer attacks, and moderate resistance to marine borers. The sapwood is susceptible to Lyctus attack. The natural durability of the wood is partly due to the presence of certain protective compounds; after extraction with a series of solvents the wood lost much of its resistance to fungal attack. The heartwood is resistant to impregnation with preservatives. Saw dust may cause allergic reactions, irritation of mucous membranes and asthma in wood workers.

Logs may have crevices filled with a yellowish powdery substance originating from the wood vessels; the substance consists of kaempferol and derivatives. Kaempferol and its glycosides have antibacterial, antifungal and anti-inflammatory activities. The wood contains 30–35% cellulose, 25–28% lignin and 14.5–16% pentosan. The solubility is 17–22% in alcohol-benzene, 1–4% in hot water and 17–22% in a 1% NaOH solution. An average oil content of 26% has been recorded for the seeds.

Adulterations and substitutes

The wood of three other Afzelia species is similar to that of Afzelia bipindensis and also traded as ‘doussié’: Afzelia africana Sm. ex Pers. and Afzelia bella Harms, both mainly exported from West Africa, and Afzelia pachyloba Harms, mainly exported from Central Africa. The excellent properties of Afzelia bipindensis wood concerning dimensional stability and high natural durability are comparable to some well-known timbers such as merbau (Intsia spp.) and teak (Tectona grandis L.f.), and to the African makore (Tieghemella heckelii (A.Chev.) Roberty) and douka (Tieghemella africana Pierre).

Description

  • Evergreen or short-deciduous medium-sized to fairly large tree up to 40 m tall; bole branchless for up to 25 m, straight and cylindrical, up to 140(–180) cm in diameter, fluted at base or with small buttresses up to 1.5 m high; bark surface yellowish brown to reddish brown, irregularly scaly and with sinuous ridges, inner bark granular, yellowish brown, with whitish streaks, aromatic; crown elongate to rounded or flattened depending on age and growing conditions, with tortuous, more or less upright branches; twigs glabrous.
  • Leaves alternate, paripinnately compound with (4–)5–7(–8) pairs of leaflets; stipules with basal parts fused and persistent, upper parts free, linear and caducous; petiole and rachis together 9–32 cm long; petiolules 3–7 mm long, often slightly twisted; leaflets opposite, oblong to elliptical, 5–13(–20) cm × 2.5–6(–7) cm, obtuse to short-acuminate at apex, glabrous, pinnately veined with 9–13 pairs of lateral veins.
  • Inflorescence a terminal or axillary panicle up to 18 cm long, short-hairy.
  • Flowers bisexual, zygomorphic, sweet-scented; pedicel 0.5–1 cm long; bracteoles 0.5–1 cm × 0.5 cm, caducous; hypanthium 1.5–4.5 cm long; sepals 4, unequal, 1–2 cm long, densely short-hairy; petal 1, 3–6 cm long, with long claw, 2-lobed, white to pink with red marking in the centre; fertile stamens 7, and 3–4 cm long, rudimentary stamens 2, and c. 1.5 cm long; ovary superior, c. 1 cm long, with short stipe, slightly hairy, style c. 4 cm long.
  • Fruit a kidney-shaped, flattened pod (8–)11–19.5 cm × 5.5–8 cm, dark brown to black, dehiscing with 2 woody valves, up to 15-seeded.
  • Seeds ovoid-ellipsoid, 2.5–3.5(–4.5) cm long, black, with 2-lobed, orange to red aril, with largest lobe covering the seed for c. 3/4.
  • Seedling with epigeal germination; hypocotyl 6–16 cm long, epicotyl 9–20 cm long, glabrous; cotyledons fleshy, oblong, erect; first 2 leaves opposite, with 2–3 pairs of leaflets, subsequent leaves alternate.

Other botanical information

Afzelia comprises about 11 species, 7 of which occur in tropical Africa and 4 in South-East Asia. It is closely related toIntsia.

Afzelia bipindensis is close to Afzelia bella Harms, which is usually a shrub or small tree in Central Africa. However, in Côte d’Ivoire and Ghana (where Afzelia bipindensis does not occur) Afzelia bella can also reach large dimensions.

Anatomy

Wood-anatomical description (IAWA hardwood codes):

  • Growth rings: 1: growth ring boundaries distinct.
  • Vessels: 5: wood diffuse-porous; 13: simple perforation plates; 22: intervessel pits alternate; 23: shape of alternate pits polygonal; 25: intervessel pits small (4–7 μm); 26: intervessel pits medium (7–10 μm); 29: vestured pits; 30: vessel-ray pits with distinct borders; similar to intervessel pits in size and shape throughout the ray cell; 42: mean tangential diameter of vessel lumina 100–200 μm; 43: mean tangential diameter of vessel lumina 200 μm; 46: 5 vessels per square millimetre; (47: 5–20 vessels per square millimetre); 58: gums and other deposits in heartwood vessels.
  • Tracheids and fibres: 61: fibres with simple to minutely bordered pits; 66: non-septate fibres present; 69: fibres thin- to thick-walled.
  • Axial parenchyma: 80: axial parenchyma aliform; 81: axial parenchyma lozenge-aliform; 82: axial parenchyma winged-aliform; 83: axial parenchyma confluent; 89: axial parenchyma in marginal or in seemingly marginal bands; (91: two cells per parenchyma strand); 92: four (3–4) cells per parenchyma strand; (93: eight (5–8) cells per parenchyma strand).
  • Rays: 97: ray width 1–3 cells; 104: all ray cells procumbent; 115: 4–12 rays per mm.
  • Mineral inclusions: 136: prismatic crystals present; 142: prismatic crystals in chambered axial parenchyma cells.
(N.P. Mollel, P. Baas & H. Beeckman)

Growth and development

On cleared sites in Gabon, the survival rate of 1-year-old planted seedlings was 85%, and 91% in the undergrowth of opened-up forest. After 6 years the survival rate was 54% on cleared sites and 44% in the forest; on open sites the average height of trees was then 8.3 m with a mean bole diameter of 7.1 cm, and in the forest 5.4 m and 5.1 cm, respectively. After 11 years the average height was 13 m on open sites and 8 m in the shade. Afzelia bipindensis seems to prefer much light for optimal early growth. In Gabon flowering trees have been recorded almost throughout the year. The roots are associated with ectomycorrhizal fungi, but often also with arbuscular myrorrhizae.

Ecology

Afzelia bipindensis occurs in evergreen and semi-deciduous forest up to 900 m altitude, usually on well-drained localities, in primary as well as secondary forest.

Propagation and planting

There are 300–350 seeds per kg. A germination rate of 95% has been recorded from tests in Congo for seed sown one week after collection of fruits below the tree. Seeds buried for slightly more than 1 cm with the aril facing upward showed the best results. Germination starts 6–16 days after sowing. In the nursery mortality of seedlings was very low.

Management

Afzelia bipindensis usually occurs scattered and in low densities in the forest. In Cameroon the average density of trees with a bole diameter of more than 60 cm varies between 0.02 and 0.2 per ha, with an average wood volume of 0.3–1.8 m³/ha. In Gabon Afzelia bipindensis appears to occur in even lower densities.

Young stands of Afzelia bipindensis are often invaded by faster growing trees and lianas, slowing down growth of Afzelia bipindensis or even causing death. Continuous weeding is necessary for good growth.

Diseases and pests

Forest elephants often remove the bark of trees and may cause serious damage.

Harvesting

The minimum bole diameter for harvesting is 80 cm in Cameroon and 60 cm in the Central African Republic. The recommended minimum bole diameter for harvesting in Gabon is 70 cm.

Handling after harvest

Prolonged stocking of logs after harvesting does not cause problems except occasional black holes in the sapwood caused by borer attacks. Logs of Afzelia bipindensis are too heavy to be transported by river.

Genetic resources

Although Afzelia bipindensis is quite widespread though occurring scattered, it is included in the IUCN Red List of threatened species as vulnerable because of intensive exploitation. In some regions it has been reported that few older trees producing seeds remained after exploitation of the forest.

Prospects

Afzelia bipindensis is a valuable timber tree that should be tried in plantations because of its slow growth in natural forest. The high value of its wood makes it economically interesting. More research is needed on its growth rate, propagation and appropriate methods of management to reduce the existing pressure on natural stands.

Major references

  • ATIBT (Association Technique Internationale des Bois Tropicaux), 1986. Tropical timber atlas: Part 1 – Africa. ATIBT, Paris, France. 208 pp.
  • Bolza, E. & Keating, W.G., 1972. African timbers: the properties, uses and characteristics of 700 species. Division of Building Research, CSIRO, Melbourne, Australia. 710 pp.
  • CTFT (Centre Technique Forestier Tropical), 1963. Résultats des observations et des essais effectués au Centre Technique Forestier Tropical sur le doussié: Afzelia spp., A. bipindensis, A. pachyloba, A. africana. Information techinique No 184, CTFT, Nogent-sur-Marne, France. 9 pp.
  • CTFT (Centre Technique Forestier Tropical), 1980. Doussié. Bois et Forêts des Tropiques 189: 37–54.
  • de Saint-Aubin, G., 1963. La forêt du Gabon. Publication No 21 du Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 208 pp.
  • Gérard, J., Edi Kouassi, A., Daigremont, C., Détienne, P., Fouquet, D. & Vernay, M., 1998. Synthèse sur les caractéristiques technologiques des principaux bois commerciaux africains. Document Forafri 11. Cirad, Montpellier, France. 185 pp.
  • Koumba Zaou, P., Mapaga, D., Nze Nguema, S. & Deleporte, P., 1998. Croissance de 13 essences de bois d’oeuvre plantées en forêt Gabonaise. Bois et Forêts des Tropiques 256(2): 21–32.
  • Sallenave, P., 1964. Propriétés physiques et mécaniques des bois tropicaux. Premier supplément. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 79 pp.
  • Sallenave, P., 1971. Propriétés physiques et mecaniques des bois tropicaux. Deuxième supplément. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 128 pp.
  • Vivien, J. & Faure, J.J., 1985. Arbres des forêts denses d’Afrique Centrale. Agence de Coopération Culturelle et Technique, Paris, France. 565 pp.

Other references

  • African Regional Workshop (Conservation & Sustainable Management of Trees, Zimbabwe), 1998. Afzelia bipindensis. In: IUCN. 2010 IUCN Red list of threatened species. Version 2010.4. [Internet] http://www.iucnredlist.org. January 2011.
  • Aubréville, A., 1968. Légumineuses - Caesalpinioidées (Leguminosae - Caesalpinioideae). Flore du Gabon. Volume 15. Muséum National d’Histoire Naturelle, Paris, France. 362 pp.
  • Aubréville, A., 1970. Légumineuses - Césalpinioidées (Leguminosae - Caesalpinioideae). Flore du Cameroun. Volume 9. Muséum National d’Histoire Naturelle, Paris, France. 339 pp.
  • Burkill, H.M., 1995. The useful plants of West Tropical Africa. 2nd Edition. Volume 3, Families J–L. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 857 pp.
  • Christy, P., Jaffré, R., Ntougou, O. & Wilks, C., 2003. La forêt et la filière bois au Gabon. Projet Aménagement Forestier et Environnement, Libreville, Gabon. 389 pp.
  • Chudnoff, M., 1980. Tropical timbers of the world. USDA Forest Service, Agricultural Handbook No 607, Washington D.C., United States. 826 pp.
  • CIRAD Forestry Department, 2009. Doussie. [Internet] Tropix 6.0. http://tropix.cirad.fr/ africa/ doussie.pdf. January 2011.
  • Fouarge, J., Quoilin, J. & Roosen, P., 1970. Essais physiques, mécaniques et de durabilité de bois de la République Democratique du Congo. Série technique No 76. Institut National pour l’Etude Agronomique du Congo (INEAC), Brussels, Belgium. 40 pp.
  • Hausen, B.M., 1981. Woods injurious to human health: a manual. Walter de Gruyter & Co., Berlin, Germany. 189 pp.
  • Koch, G., Richter, H.G. & Schmitt, U., 2006. Topochemical investigation on phenolic deposits in the vessels of afzelia (Afzelia spp.) and merbau (Intsia spp.) heartwood. Holzforschung 60: 583–588.
  • Louppe, D., Deleporte, P., Vigneron, P. & Béhaghel, I., 1999. Projet OIBT PD 10/95 REV. 2 (F). Evaluation des essences indigènes de bois d’œuvre en vue du développement des plantations forestières au Gabon. Rapport final Assistance technique du CIRAD-Forêt, Libreville – Montpellier. 201 pp.
  • Ng, N.Q., Lapido, D.O., Kang, B.T. & Atta-Krah, A.N., 1993. Multipurpose tree and shrub germplasm evaluation and conservation at IITA. In: Proceedings of the International Consultation on the Development of the ICRAF MTP-Germplasm Resource Centre, Nairobi, 2–5 June 1992. ICRAF, Nairobi, Kenya.
  • Normand, D. & Paquis, J., 1976. Manuel d’identification des bois commerciaux. Tome 2. Afrique guinéo-congolaise. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 335 pp.
  • Raponda-Walker, A. & Sillans, R., 1961. Les plantes utiles du Gabon. Paul Lechevalier, Paris, France. 614 pp.
  • Takahashi, A., 1978. Compilation of data on the mechanical properties of foreign woods (part 3) Africa. Shimane University, Matsue, Japan. 248 pp.
  • Wilczek, R., Léonard, J., Hauman, L., Hoyle, A.C., Steyaert, R., Gilbert, G. & Boutique, R., 1952. Caesalpiniaceae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 3. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. pp. 234–554.
  • Wilks, C. & Issembé, Y., 2000. Les arbres de la Guinée Equatoriale: Guide pratique d’identification: région continentale. Projet CUREF, Bata, Guinée Equatoriale. 546 pp.

Sources of illustration

  • Aubréville, A., 1970. Légumineuses - Césalpinioidées (Leguminosae - Caesalpinioideae). Flore du Cameroun. Volume 9. Muséum National d’Histoire Naturelle, Paris, France. 339 pp.
  • Wilczek, R., Léonard, J., Hauman, L., Hoyle, A.C., Steyaert, R., Gilbert, G. & Boutique, R., 1952. Caesalpiniaceae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 3. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. pp. 234–554.
  • Wilks, C. & Issembé, Y., 2000. Les arbres de la Guinée Equatoriale: Guide pratique d’identification: région continentale. Projet CUREF, Bata, Guinée Equatoriale. 546 pp.

Author(s)

  • J. Gérard, UPR Production et valorisation des bois tropicaux et méditerranéens, 73 rue Jean-François Breton, TA B-40 / 16 (Bât. 16, Bur. 123), 34398 Montpellier Cédex 5, France
  • D. Louppe, CIRAD, Département Environnements et Sociétés, Cirad es-dir, Campus international de Baillarguet, TA C 105 / D (Bât. C, Bur. 113), 34398 Montpellier Cédex 5, France

Correct citation of this article

Gérard, J. & Louppe, D., 2011. Afzelia bipindensis Harms. In: Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 7 February 2019.