ISSN 2375-1134
African Journal of Agriculture ISSN 2375-1134 Vol. 7 (7), pp. 001-016, July, 2020. © International Scholars Journals
Full Length Research Paper
Ecological behaviour and biogeography of endemic species of the genus Piper L. in Africa: A case of the Guineo-Congolean region
Valery Noiha Noumi1*, Louis Zapfack1 and Bonaventure Sonke2
1Laboratory of Plant Systematic and Ecology, Department of Plant Biology, Faculty of Science, University of Yaounde I, P. O. Box 812 Yaounde-Cameroon.
2Department of Biological Sciences, Higher Teacher Training School, University of Yaoundé I, P. O. Box 047, Yaoundé, Cameroon.
Accepted 13 May, 2020
Abstract
The aim of this study was to establish the ecology and the distribution patterns of the endemics Piper L. in the Guineo-Congolean region including the Lower Guinea, the Higher Guinea, the Congo Basin and the Mosaic of Lake Victoria. The distribution stretches from Senegal to Tanzania. Piper capensis and Piper guineense are both represented in Lower Guinea and Congo Basin; these phytochoria are eco-regions of endemism in Africa. P. guineense, hemi-epiphyte liana, appears mostly in fragmented vegetations. Its distribution is extended up to 1,500 m. P. capensis is mostly abundant between 1,000 to 2,500 m where homogeneous populations are often made in the gaps. Members of P. capensis are dwarves at the level of the understory and rarely attain 1 m in height; however, those from gaps are often between 2 to 3 m. The variation in the height of individuals is closely related to light; a phytosociological study has shown an abundance of herbs within the population of P. capensis. The dwarfism of the individuals in the understory is assigned to an adaptation character of the species. This dwarfism is a consequence of its plagiotropic branches that is beneficial for photosynthesis. The “ late turning green” of leaves save the individuals of the understory from leaf predators; in the gap where the sunlight boosts the process of photosynthesis, certain individuals establish “opportunist” symbiosis with ants. The flowering is related to the humid periods of the year. Fruits are mostly abundant during the dry season.
Key words: Adaptation, distribution, Guineo-Congolean region, Piper, symbiosis.