ELVIRE HORTENSE BIYE1*, CHRISTIAN DJIMARABEYE1, ATHINA ARELA MADELEINE MENYE2
¹ Plant Biology Department, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon
2 Camerounaise de Construction du Barrage de Nachtigal, P.O. Box 6283, Ndokoa, Cameroon
*Corresponding author: elvira.hortense@yahoo.com
Received: 28 Jan 2026, Reviewed: 24 March 2026, Revised: 05 May 2026, Accepted: 07 May 2026, Published: 06 Aug 2026
https://doi.org/10.63342/cjbbs2026.34.04.en
ABSTRACT
The construction of large hydroelectric infrastructure often leads to significant soil degradation, particularly through the disposal of inert waste. At the Nachtigal Dam construction site in Cameroon, two concrete waste disposal sites in zones A and B were identified for ecological rehabilitation. In this study, we assessed the effectiveness of a three-layered soil remediation technique on the growth of 1,046 plants, selected based on both a survey conducted at the local community on products most commonly used and on an ecological assessment of the surrounding area, across a total area of 24,657.72 m², i.e. 8924.72m2 in zone A and 15733m2 in zone B. A mixed planting strategy incorporating 40% species producing non-timber forest products (NTFPs) and 60% woody species has been implemented to promote ecological functionality and socio-economic benefits. Post-planting monitoring through observation and counting revealed an overall survival of approximately 85%, despite localized erosion and varying survival rates within and between species. Thus, the rehabilitated areas exhibit strong regeneration potential, indicating that engineered soil profiles combined with structured planting of mixed species can effectively restore degraded concrete waste areas. This study sheds light on assisted regeneration practices relevant to large infrastructure projects in tropical forest regions.
Keywords: Assisted reforestation, conservation, inert waste, rehabilitation, soil types.
RÉSUMÉ
La construction de grandes infrastructures hydroélectriques entraîne souvent une dégradation importante des sols, notamment par le dépôt de déchets inertes. Sur le site de construction du barrage de Nachtigal au Cameroun, deux zones de dépôt de déchets en béton, A et B, ont été identifiées en vue d’une réhabilitation écologique. Dans cette étude, nous avons évalué l’efficacité d’une technique de remédiation des sols en trois couches sur la croissance de 1 046 plants, sélectionnés à la fois sur la base d’une enquête menée auprès des communautés locales sur les produits les plus couramment utilisés et d’une évaluation écologique de la zone environnante, établis sur une superficie de 24 657,72 m², soit 8 924,72 m² pour la zone A et 15 733 m² pour la zone B. Une stratégie de plantation mixte intégrant 40 % d’espèces produisant des produits forestiers non ligneux (PFNL) et 60 % d’espèces ligneuses a été mise en œuvre afin de favoriser à la fois la fonctionnalité écologique et les bénéfices socio-économiques. Le suivi post-plantation, basé sur l’observation et le comptage, a révélé un taux de survie global d’environ 85 %, malgré une érosion localisée et des variations de survie au sein et entre les espèces. Les zones réhabilitées présentent ainsi un fort potentiel de régénération, indiquant que des profils de sol reconstitués, combinés à une plantation structurée d’espèces mixtes, peuvent restaurer efficacement des zones dégradées par des déchets de béton. Cette étude met en évidence des pratiques de régénération assistée pertinentes pour les grands projets d’infrastructure en milieu forestier tropical.
Mots-clés : reforestation assistée, conservation, déchets inertes, réhabilitation, types de sols.
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