Summary
Quantitative data of habitat and vegetation from 70 relevés of the Akagera park were submitted to different ordination and classification methods. Sampling problems have been treated as objectively as possible.
The habitat factors which have an important effect upon vegetation are:
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the characteristics of adsorbant complex of soil,
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the characteristics of the tree layer,
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the texture of soil.
The different ordination and numerical classification methods applied to the same set of data lead to consistent results. The numerical classification is preferred to Braun-Blanquet's method.
The results are compared with the previous findings in the same region and the future developments of quantitative methods are discussed.
Résumé
Des données quantitatives sur le milieu et la végétation de 70 relevés du parc de l'Akagera ont été soumises à différentes méthodes d'ordination et de classification. Les problèmes d'échantillonnage ont été traités de façon aussi objective que possible.
Les facteurs du milieu qui ont une action importante sur la végétation sont:
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les caractéristiques du complexe adsorbant du sol,
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les caractéristiques de la strate ligneuse,
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la texture du sol.
Les différentes méthodes d'ordination et de classification numérique appliquées au même ensemble de données conduisent à des résultats compatibles. La classification numérique est préférée à la méthode de Braun-Blanquet.
Les résultats sont comparés aux conclusions obtenues précédemment dans la même région et les développements futurs des méthodes quantitatives sont discutés.
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Plant nomenclature conforms to the recent publications on the African Flora, i.e.: Flore d'Afrique Centrale (Zaïre, Rwanda-Burundi), Flora of Tropical East Africa, Flora of West Tropical Africa, Flora Zambesiaca and A.E.T.F.A.T. Bulletin.
All data presented in this work have been collected during my stage in the National Institute of Scientific Research of Rwanda, during the years 1970 and 1971. Most of the computations have been carried out on the Nijmegen University's IBM 370/155; I am happy to thank Dr E. van der Maarel and Dr J. G. M. Janssen for their welcome and assistance.
This paper is part of a thesis presented at the Liège University on 7th November 1973; during the writing, I had many interesting discussions with Professor Lambinon and I thank him for his remarks and purposes.
I could take much advantage of Professor Dagnelie's great experience in biometry.
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Bouxin, G. Ordination and classification in the savanna vegetation of the akagera park (Rwanda, Central Africa). Plant Ecol 29, 155–167 (1975). https://doi.org/10.1007/BF02390007
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DOI: https://doi.org/10.1007/BF02390007