Congo 125Forest Classification White's memoir and map, published by Unesco, was the result of some 1 5 years of cooperation between Unesco and the Association pour I'Etude Taxonomique de la Flore de I'Afrique Tropicale (AETFAT). AETFAT's Vegetation Map Committee, whose members compiled the materials from which White worked, included many distinguished autliorities. Building upon earlier works such as the well-known Yangambi classification of tropical Africa (Trochain, 1957) and Keay's (1959) vegetation map of Africa, White's classification has withstood scrutiny for almost a decade, and looks set to do so for several more. The greatest threat to its boundaries, predictably, is the rapid expansion of anthropic landscapes at the expense of natural vegetation.White's classification identifies 1 6 major vegetation types or formations, all based on structure and physiognomy without recourse to climatic or other environmental considerations (Table 1.1). There is a wide diversity of woody vegetation types, including forest, thicket, shrubland, Afroalpine vegetation, scrubland, mangrove and bamboo; woodland being the most widespread (White, 1983, p. 47). Africa differs from tropical Asia in the occurrence of 4 This adas is concerned with tropical forests, therefore the montane forests of temperate southern Africa, which are shown here for completeness, are not considered within it. Lowlond forest Montone forest Swamp Mon grove see Toble 1 .2 (or a fuil explonotion of itie forest types included 14 Halophytic vegetation (saline and brackish swamp). Formation of Distinct Physiognomy but Restricted Distribution 15 Bamboo Umiatural Vegetation 16 Anthropic landscapes (Source: White, 1983) Categories used to define various rain forest formations in this Atlas Lowland dryland Wetland inland Aiontane Wetland coastal rainforest (swamp) forest rainforest (mangrove) forest Notes 1forest, i.e. 'those which cover with their various storeys and undergrowth a high proponion of the ground and do not have a continuous dense grass layer allowing grazing and spreading of fires. They are often, but not always, multistoreyed. They may be evergreen, semi-deciduous, deciduous, wet, moist or dry' (FAOAJNEP, 1981). In other words, this definition includes the mangrove, swamp, montane and lowland forests for which the Atlas maps give separate figures but also includes areas of forest along river banks in dry country and dry forests, neither of which is considered here. Forest product information (see Table 1.3) is compiled from the 1991 FAO Yearbook (FAO, 1991).Country chapters use a standard format as far as is practicable, with a preliminary overview followed by an introduction to the
