Biodiversité ligneuse en milieux urbains : cas de la ville de Bunia, province de l’Ituri en République démocratique du Congo (RDC)

The floristic and structural study of plant biodiversity remains an essential tool for implementing strategies for biodiversity conservation and ecosystem management. In urban environments, the study of woody biodiversity still presents a challenge for assessing species richness. Although sparse, this biodiversity plays an important ecosystem role and contributes to the sequestration of atmospheric CO2 by releasing oxygen useful for other living things. The objective of this study is to analyze the floristic composition of woody biodiversity in an urban environment, specifically the city of Bunia. More specifically, it aims to assess the floristic and structural variability of trees within the three communes (Mbunya, Nyakasanza, and Shari) that make up the city. The results obtained after inventories of trees with a DBH (Diameter at Breast Height) ≥10 cm indicate floristic and structural variability among the communes. Out of a total of 2,311 trees inventoried, the total average density in the city of Bunia is 110.05 trees/ha. The commune of Nyakasanza shows a high average density of (128.29±23.47) trees/ha, compared to a low average of (100.57±28.96) trees/ha obtained in the commune of Shari. Density varies significantly according to the plots (ANOVA 2: F=5.989; p-value=9.31×10−16) but statistically it does not vary according to the communes (F=1.492; p-value=0.225). The inventoried trees located in the 10−20 cm and 20−30 cm diametric classes are numerous, which demonstrates that the woody biodiversity of the city of Bunia consists of small-sized trees and is dynamic. Several ecologically important species were identified in the city of Bunia, such as Eucalyptus globulus (IVI=38.20), Mangifera indica (IVI=12.81), Persea americana (IVI=16.95), and Grevillea robusta (IVI=10.11). However, the family Myrtaceae is largely present in all communes. We note that there is a significant difference in the floristic composition between the communes (F=5.279, p-value=0.05574).