Afforestation des savanes et dynamique écologique du sous-bois : effets contrastés des plantations d’Acacia en République démocratique du Congo

Crispin Ilunga Balo; Roger Lomalisa Katusi; Constatin Ayingweu Lubini; Henry Nkunzi Mbale; Félicien Luyeye Lukoki; Pisco Munkolo Menga

doi:10.59228/rcst.026.v5.i2.278

Afforestation of Savannas and Understory Ecological Dynamics: Contrasting Effects of Acacia Plantations in the Democratic Republic of Congo

Authors

Crispin Ilunga Balo Laboratoire de Biodiversité végétale, Ecologie et Ethnobotanique, Mention Sciences de la vie, Faculté des Sciences et Technologies, Université de Kinshasa, République Démocratique du Congo Author
Roger Lomalisa Katusi Université de Kisangani, Faculté de Sciences, Département d’écologie et gestion des ressources végétales, Province de la Tshopo, B. P. 2012, Université de Kisangani, République Démocratique du Congo Author
Constatin Ayingweu Lubini Laboratoire des systèmes, de la biodiversité, de la conservation de la nature et des savoirs endogènes, Département des sciences de l’environnement, Faculté des sciences, Université de Kinshasa, République démocratique du Congo Author
Henry Nkunzi Mbale Laboratoire de Biodiversité végétale, Ecologie et Ethnobotanique, Mention Sciences de la vie, Faculté des Sciences et Technologies, Université de Kinshasa, République Démocratique du Congo Author
Félicien Luyeye Lukoki 1Laboratoire de Biodiversité végétale, Ecologie et Ethnobotanique, Mention Sciences de la vie, Faculté des Sciences et Technologies, Université de Kinshasa, République Démocratique du Congo Author
Pisco Munkolo Menga Laboratoire de Biodiversité végétale, Ecologie et Ethnobotanique, Mention Sciences de la vie, Faculté des Sciences et Technologies, Université de Kinshasa, République Démocratique du Congo Author

DOI:

https://doi.org/10.59228/rcst.026.v5.i2.278

Keywords:

Acacia plantations, Acacia auriculiformis, Acacia mangium, Savanna afforestation, Understory diversity, Floristic composition

Abstract

Forest plantations play an important role in timber production, carbon sequestration, and tropical landscape restoration, but their effects on plant biodiversity depend strongly on ecological context. This study assessed the impact of Acacia auriculiformis A.Cunn. ex Benth. and Acacia mangium Willd. Plantations on the diversity, composition, and structure of understory plant communities in the Batéké Plateau savannas and the forest ecosystems of the Kisantu Botanical Garden, Democratic Republic of the Congo. Floristic surveys conducted using the Braun-Blanquet method were used to evaluate species richness, diversity indices, and floristic composition. In savanna ecosystems, plantations significantly reduced plant diversity. Mean species richness declined from 41.3 ± 7.8 species per plot in natural savannas to 31.3 ± 3.4 species in A. auriculiformis plantations and 18.0 ± 2.7 species in A. mangium plantations (ANOVA, p < 0.001). At the habitat level, 98 species were recorded in natural savannas, compared with 50 and 35 species in A. auriculiformis and A. mangium plantations, respectively. The proportion of savanna specialist species decreased markedly from 71.4% in natural savannas to 26.0% and 25.7% in the respective plantations, while ruderal species became dominant. In forest ecosystems, A. auriculiformis plantations maintained high species richness (54.5 ± 9.1 species per plot), comparable to that of mature secondary forests (53.8 ± 7.9 species per plot). However, floristic composition indicated communities corresponding to intermediate stages of secondary succession. These findings highlight that plantation effects are context-dependent, potentially simplifying savanna communities while supporting regeneration processes in degraded forest landscapes.

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