Graminees du Cameroun

A.P.M. van der Zon

    Research output: Thesisexternal PhD, WU

    Abstract

    <p>The grasses are one of the most important plant families of Cameroon. The dry savanas of the North and the mountainous areas of central and western Cameroon are extensive grass areas which are of utmost importance for cattle and fauna in general.<p>Several of the importantant traditional agricultural crops such as sorghum, maize and rice are members of the grass family.<p>For botanical education and research of plant communities and grasslands the knowledge of grasses is of great importance. At the Cameroonian universities and the Garoua wildlife school there was a great need of a practical grass flora of Cameroon in the french language.<p>The first part of the grasses of Cameroon deals with the geology, topography, soils and climate. Next is a discussion of the phytogeography of the grasses and thereafter an overview is given of the prairies and their use by cattle and wildlife.<p>Three more or less clear defined plant geographical vegetation zones are distinguished, each of them can be further subdivided: the Soudanian zone (North, and the lower part of the uplands), the Afro-Montaneous zone (the mountains above 2000 m) and the Congo-Guinean zone (forest zone), each with its typical species and genera. The northern slope of the Adamaoua plateau is a clear boundary within the Soudanian zone. The uplands are the richest in species diversity of grasses.<p>The open vegetations of Cameroun are often dominated by the grasses, and specimens of these areas are well represented in plant collections. The presence of the Garoua wildlife school has stimulated the knowledge of the vegetation of northern Cameroon. Also around Bamenda (research station Bambui) and on Mt Cameroon many grasses have been collected.<p>In the rain forest area of Cameroon the grasses are poorly represented in the collections because of the little importance forest botanists attach to grasses. They generally look upwards instead of downwards and think of grasses as secondary species. However, next to the typical shade-species there are quite a few species typical for the open patches in the forest, in particular along the streams and rivers.<p>Of the flora the Andropogoneae are the most striking savana-group and often very dominating. More to the North the Eragrostideae and Aristideae become more important. The Paniceae occur everywhere but are less dominating. A number of smaller bamboo-like groups are shade-tolerant and occur in the rain forest.<p>The bend to the south of the vegetation zones as is so obvious in the western Sahel, hardly find expression in Cameroon. <em>Andropogon gayanus</em> is a very clear indicator species in this respect. Although the extreme north of Cameroon has suffered seriously from the drought and the vegetation is very degradated, compared with a few decennia ago no obvious modification of the location of the vegetation zones is visible.<p>Grasses are well adapted to fire. Frequent burning causes grasses to dominate. This annual burning is of importance for the cattle as fresh grass becomes available each year. When fires are prevented, the vegetation gets more and more dominated by woody species.<p>The wildlife has a more mixed and broader utilisation of the vegetation. More emphasis should be given to a better and sustainable exploitation of this wildlife.<p>In the appendix a fist of species is given with notes on the distribution in Cameroon, in Africa and worldwide, and of the most important vegetation types they occur in.<p>The second volume of the flore (the Flora) treats the 19 tribes of the grasses, occurring in Cameroon. The lay-out follows the model of the Flore du Cameroun.<p>The grass flora of Cameroon is very rich. There are 433 species of grasses, in 125 genera and 19 tribes. Two species new to science are described in the appendix and two new combinations are given.<p>Two identification keys are presented, one leading to the tribes and the other to the genera. For each of the tribes and genera keys are provided, leading to the species. For each species there is a description of the general habit, with leaf shape, details on the inflorescences and the spikelets. After the type-indication particulars are given about the habitat, the vernacular names and the uses. There are 120 plates with drawings of 244 species. The microfiches in the back present the herbarium specimens examined. Details include geographic locality and indication where the specimens are lodged with the usual herbarium acronyms (K, L, P, WAG, etc.).
    Original languageFrench
    QualificationDoctor of Philosophy
    Awarding Institution
    Supervisors/Advisors
    • van der Maesen, L.J.G., Promotor
    • Veldkamp, J.F., Promotor, External person
    Award date5 Jun 1992
    Place of PublicationS.l.
    Publisher
    Publication statusPublished - 1992

    Keywords

    • grasses
    • poaceae
    • plants
    • identification
    • flora
    • cameroon
    • fodder grasses

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