PROTA, Introduction to Timbers
PROTA 7 (1), 2008. Plant resources of tropical Africa. vol. 7 (1). Timbers, volume 1. ed. by D. Louppe, A.A. Oteng-Amoako & M. Brink. Wageningen, PROTA Foundation - Backhuys - CTA. 704 p.
PROTA 7 (2), 2012. Plant resources of tropical Africa. vol. 7 (2). Timbers, volume 2. ed. by R.H.M.J. Lemmens, D. Louppe, & A.A. Oteng-Amoako. Wageningen, PROTA Foundation - CTA. 804 p.
Choice of species of volume 1
PROTA 7(1): ‘Timbers 1’ is the first of 2 volumes describing the wild and cultivated plant species of tropical Africa used for their timber. Some of these are traded on the international timber market, but many are only used locally, for construction purposes or the production of furniture, implements and utensils. Bamboos of which the stems are used for construction are also included in this commodity group. Most species have several other, secondary, uses. PROTA assigns one primary use and, if relevant, one or more secondary uses to all plant species used in Africa. For instance, the primary use of Chrysophyllum lacourtianum De Wild. is as a timber tree, and thus it is treated in PROTA 7, but it has several secondary uses, e.g. the fruits are eaten and the bark is used in traditional medicine. The timber of Chrysophyllum albidum G.Don is also commonly used, but the primary use of this species is as a fruit, and consequently it is described in PROTA 6: ‘Fruits’.
Table 1. Families treated in PROTA 7(1) and the division of species.
In PROTA 7(1), some species are treated which, in addition to the primary use as timber, also have another primary use and consequently are described in 2 PROTA books. These species are Ceiba pentandra (L.) Gaertn. (also in PROTA 16: ‘Fibres’), Eucalyptus camaldulensis Dehnh. (also in PROTA 10: ‘Fuel plants’), Pterocarpus angolensis DC. (also in PROTA 3: ‘Dyes and tannins’) and Pterocarpus soyauxii Taub. (also in PROTA 3: ‘Dyes and tannins’).
In ‘Timbers 1’ all primary-use timber species of 25 important timber-containing families are treated. ‘Timbers 2’ will comprise the timber species of the remaining families. Comprehensive descriptions are given of 113 important timber species. These major timbers comprise mostly wild species, but also several cultivated or partly domesticated species. The accounts are presented in a detailed format and illustrated with a line drawing and a distribution map. In addition, accounts of 167 timbers of minor importance are given. Because information on these species is often scanty, these accounts are in a simplified format and usually do not include a drawing or map. For another 231 species the information was too scarce to justify an individual treatment and they have only been mentioned in the accounts of related species.
Choice of species of volume 2
PROTA 7(2): ‘Timbers 2’ is the second of 2 volumes describing the wild and cultivated plant species of tropical Africa used in the first place for their timber. Some of these are traded on the international timber market, but many are only used locally, for construction purposes or the production of furniture, implements and utensils. Bamboos of which the stems are used for construction are also included in this commodity group (see PROTA 7(1)). Most species have several other, secondary, uses. PROTA assigns one primary use and, if relevant, one or more secondary uses to all plant species used in Africa. For instance, the primary use of Terminalia ivorensis A. Chev. is as a timber tree, and thus it is treated in PROTA 7, but it has several secondary uses, e.g. it is used as a shade tree for crops and as a roadside tree, whereas the bark and leaves are used in traditional medicine. The timber of Terminalia catappa L. is also commonly used, but the primary use of this species is as an ornamental tree, and consequently it is described in PROTA 4: ‘Ornamentals’.
In PROTA 7(2), some species are treated which, in addition to the primary use as timber, also have another primary use and consequently are described in 2 PROTA books. These species are Anogeissus leiocarpa (DC.) Guill. & Perr. (also in PROTA 3: ‘Dyes and tannins’), Erythrophleum ivorense A.Chev., Erythrophleum suaveolens (Guill. & Perr.) Brenan, Sacoglottis gabonensis (Baill.) Urb., Uapaca guineensis Müll.Arg. and Uapaca mole Pax (also in PROTA 11(1): ‘Medicinal plants 1’, the latter under the synonym Uapaca paludosa Aubrév. & Leandri), and Irvingia gabonensis (Aubry-Lecomte ex O’Rorke) Baill., Ongokea gore (Hua) Pierre, Pycnanthus angolensis (Welw.) Warb. and Ricinodendron heudelotii (Baill.) Pierre ex Heckel (also in PROTA 14: ‘Vegetable oils’).
‘Timbers 1’ comprised the timber species of 25 important families. In ‘Timbers 2’ all primary-use timber species of 60 timber-containing families are treated.
Table 2. Families treated in PROTA 7(2) and the division of species.
Comprehensive descriptions are given of 150 important timber species. These major timbers comprise mostly wild species, but also several cultivated or partly domesticated species. The accounts are presented in a detailed format and illustrated with a line drawing and a distribution map. In addition, accounts of 164 timbers of minor importance are given. Because information on these species is often scanty, these accounts are in a simplified format and usually do not include a drawing. For another 379 species the information was too scarce to justify an individual treatment and they have only been mentioned in the accounts of related species.
In this final volume, all 1148 ‘secondary use’ timbers are listed as ‘Timbers with other primary use’ and referred to other Handbook volumes.
Family: Apart from the classic family name, the family name in accordance with the Angiosperm Phylogeny Group (APG) classification is also given where it differs from the classic name.
Synonyms: Only the most commonly used synonyms and those that may cause confusion are mentioned.
Vernacular names: Only names in official languages of regional importance in Africa are included: English, French, Portuguese and Swahili. It is beyond the scope of PROTA to give an extensive account of the names of a species in all languages spoken in its area of distribution. Checking names would require extensive fieldwork by specialists. Although regional forms of Arabic are spoken in several countries in Africa, the number of African plant species that have a name in written, classical Arabic is limited. Arabic names are therefore omitted. Names of plant products are mentioned under the heading ‘Uses’.
Origin and geographic distribution
To avoid long lists of countries in the text, a distribution map is added for major species. The map indicates in which countries a species has been recorded, either wild or planted. It should be realized that for many species these maps are incomplete because they are prepared on the basis of published information, the quantity and quality of which varies greatly from species to species. This is especially the case for wild species which are not or incompletely covered by the regional African floras, and for cultivated species which are only planted on a small scale (e.g. in home gardens). For some countries (e.g. Central African Republic, Chad, Sudan, Angola) there is comparatively little information in the literature. Sometimes they are not covered by recent regional or national floras and although species may be present there, this cannot be demonstrated or confirmed. For some major species, a distribution map has been omitted because there is too little information on distribution.
Wood appearance (i.e. colour, grain, texture), physical properties (density, drying properties, shrinkage rates, movement in service) and mechanical properties (strength, elasticity, hardness) of the wood are given on the basis of literature and as much as possible in quantitative terms and in a standardized order. This is followed by a description of the working properties and the durability of the wood.
A morphological characterization of the species is given. The description is in ‘telegram’ style and uses botanical terms. Providing a description for the general public is difficult as more generally understood terms often lack the accuracy required in a botanical description. A line drawing is added for all major and some lesser-known species to complement and visualize the description.
A wood-anatomical description has been prepared for each major timber species. The descriptions of the hardwood species are based on the IAWA (International Association of Wood Anatomists) list for hardwood identification (Wheeler, Baas & Gasson, 1989), those of the softwood species on the IAWA list for softwood identification (Richter, Grosser, Heinz & Gasson, 2004). All descriptions have been compiled in the PROTA Wood Anatomy Workshop (16−25 May, 2007, Montpellier, France) as part of a training of African wood anatomists under expert guidance. The compilers of each description are mentioned at the end of the paragraph ‘Anatomy’.
For many descriptions the InsideWood database (http://insidewood.lib.ncsu.edu) has been used as a basis, but for all descriptions microscopic sections of wood from the slide collections of CIRAD (Montpellier, France), the Royal Museum for Central Africa (Tervuren, Belgium), the Royal Botanic Gardens (Kew, UK) , and the National Herbarium of the Netherlands (Leiden, Netherlands) have been investigated during the wood anatomy workshop. The final descriptions have been included in the InsideWood database.
The character codes given in parentheses () indicate characters which are variable or rarely occur in the material studied. In character code 23 a question mark (?) is sometimes added, indicating the presence of small pits but difficulties to see the pit outline.
Descriptions of husbandry methods including fertilizer application, irrigation, and pest and disease control measures are given under ‘Management’ and under ‘Diseases and pests’. These reflect actual practices or generalized recommendations, opting for a broad overview but without detailed recommendations adapted to the widely varying local conditions encountered by farmers. Recommendations on chemical control of pests and diseases are merely indicative and local regulations should be given precedence. PROTA will participate in the preparation of derived materials for extension and education, for which the texts in this volume provide a basis, but to which specific local information will be added.
The genetic diversity of many plant species in Africa is being eroded, sometimes at an alarming rate, as a consequence of habitat destruction and overexploitation. The replacement of landraces of cultivated species by modern cultivars marketed by seed companies is another cause of genetic erosion. Reviews are given of possible threats for plant species and of the diversity within species, and reference is made to the IUCN Red list of threatened species where relevant. Information on ex-situ germplasm collections is mostly extracted from publications of Bioversity International (formerly the International Plant Genetic Resources Institute – IPGRI).
The main objective of the list of references given is to guide readers to additional information; it is not intended to be complete or exhaustive. Authors and editors have selected two categories of references; ‘major references’ are limited to 10 references (5 for minor species), the number of ‘other references’ is limited to 20 (10 for minor species). The references listed include those used in writing the account. Where the internet was used, the website and date are cited.
Editors of volume 1
- D. Louppe, CIRAD, Département Environnements et Sociétés, Cirad es-dir, Campus international de Baillarguet, TA C-DIR / B (Bât. C, Bur. 113), 34398 Montpellier Cedex 5, France
- A.A. Oteng-Amoako, Forestry Research Institute of Ghana (FORIG), University P.O. Box 63, KNUST, Kumasi, Ghana
- M. Brink, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
Editors of volume 1
Editors: R.H.M.J. Lemmens D. Louppe A.A. Oteng-Amoako
Associate editors: E.A. Obeng J.R. Cobbinah
- R.H.M.J. Lemmens, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
- L.P.A. Oyen, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
- J.R. Cobbinah, Forestry Research Institute of Ghana (FORIG), University P.O. Box 63, KNUST, Kumasi, Ghana
- E. Boer, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands