Status of Natural Regeneration of Guibourtia demeusei (J. Léonard) in the Congolese Tropical Forest
Alain Shona Omokoko *
Department of Water and Forests, Laboratory of Eco-Agriculture and Tropical Agroforestry, IFA-Yangambi, Democratic Republic of the Congo.
Felly Kombozi Bamanga
Department of Water and Forests, Faculty of Renewable Natural Resource Management, University of Kisangani, Democratic Republic of the Congo.
Louison Osako Omelonga
Department of Biotechnology, Faculty of Natural Sciences and Biotechnology, University of Kisangani, Democratic Republic of the Congo.
Hippolyte Nshimba Seya Wa Malale
Department of Ecology and Plant Resource Management, Faculty of Natural Sciences and Biotechnology, University of Kisangani, Democratic Republic of the Congo.
Dimanche Yenga Bombeku
Department of Water and Forests, Laboratory of Eco-Agriculture and Tropical Agroforestry, IFA-Yangambi, Democratic Republic of the Congo.
*Author to whom correspondence should be addressed.
Abstract
Natural regeneration plays a crucial role in maintaining tropical forest ecosystems and ensuring the sustainable management of valuable timber species in the Congo Basin. This study focuses on the status of the natural regeneration of Guibourtia demeusei in the tropical forest of Yangambi.Was conducted in the forest areas of the Central Basin, within the Yangambi Biosphere Reserve, located in the Isangi district, Democratic Republic of Congo. The objective was to assess the dynamics of natural regeneration of Guibourtia demeusei in the natural forests of Yangambi by quantifying the abundance of seedlings originating from selected seed trees and by analyzing the relationship between the dendrometric characteristics of these trees and regeneration success under forest cover. A total of six one-hectare plots were established in Yangambi, within which seedlings of different height classes were measured and their x and y coordinates recorded. Each of the six plots contained one seed tree, except plots 3, 5, and 6. In total, 916 seedlings were recorded in Yangambi, corresponding to a density of 152.6 stems/ha. The S1 height class had the highest number of individuals (491 stems across the six hectares, i.e., 81.8 stems/ha) compared to the other classes, and their number decreased as individual size increased. A strong positive correlation (r ≈ 0.95) was observed between the number of seed trees and seedling density. Likewise, a moderate negative correlation (r ≈ -0.58) was found between diameter at breast height (DBH) and seedling density. A moderate negative correlation was also observed between the number of seed trees and DBH (r = -0.66), although it was not statistically significant. In conclusion, the natural regeneration of Guibourtia demeusei remains fragile in the study area. Further research is therefore recommended to deepen the understanding of dispersal and regeneration mechanisms, with the aim of improving sustainable management practices in Congolese tropical forests.
Keywords: Congo Basin, forest stands, Guibourtia demeusei, regeneration, Yangambi