Browsing by Author "Bongo, Gédéon Ngiala"

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    Identification of invasive alien species and assessment of ecological factors in the pool Malebo in Kinshasa, Democratic Republic of the Congo
    (Видавництво Львівської політехніки, 2023-02-28) Mukendi, Michael Tshibangu; Mbale, Henri Kunzi; Menga, Pisco Munkolo; Bongo, Gédéon Ngiala; Lukoki, Félicien Luyeye; University of Kinshasa
    The aim of this study was to identify invasive aquatic species and assess ecological factors in 5 islands, namely Mipongo, Japon, Kabongo, Kingabwa and Molondo.of the Pool Malebo. A floristic inventory was conducted around these sites and physico-chemical characteristics were measured in each island between 8:00am and 3:00pm using an appropriate electronic probe. The floristic affinity between sites was determined by cluster analysis using MVSP software version 4.03, after highlighting the Jaccard's coefficient based on the presence/absence of species in the different collection sites. The comparison between the sites was carried out using the ANOVA test with SPSS 25 software for physico-chemical parameters. The findings show that 24 species were identified as invasive out of which, six were dominant, namely Eichhornia crassipes, Echinocloa pyramidalis, Pistia stratiotes, Leersia hexandra, Ludwigia abissinega, and Ludwigia sp. No significant differences were observed for the temperature (F=0.42 and p=0.66), conductivity (F=1.55 and p=0.25) and turbidity (F=2.28 and p=0.14) for the three sites. While the pH (F=4.98; p=0.026; LSD=0.361), dissolved oxygen (F=12; p=0.001; LSD=3.65) and salinity (F=4.06; p= 0.04; LSD= 1.69) showed significant variation in the three sites. The formation of vegetation groups around these islands in the Pool Malebo would also be justified by the influence of these parameters. The spread of invasive alien species on the surface of the river needs to draw more attention to scientists, policy makers and government in order to find a way to a good management of these species.
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    Impact of physico-chemical characteristics on aquatic biodiversity of five prospected wetlands from Kipushi mining site in Haut-Katanga province in the Democratic Republic of the Congo
    (Видавництво Львівської політехніки, 2023-02-28) Mbale, Henri Kunzi; Mwamba, Marc wa Tshakapeta; Bongo, Gédéon Ngiala; University of Kinshasa; Environmental Assessment, Building capacity and Consulting, Kinshasa; Centre Mbale Kunzi of Ecology and Biodiversity Monitoring in the Congo Basin
    The development of mining industrialization is one of the factors that have favored the pollution of aquatic ecosystems. The main purpose of this study was to assess the influence of physico-chemical parameters of surface waters on the abundance of hydrophytes in 5 wetlands in Kipushi city, Haut-Katanga Province in DRC. Samples were collected from four rivers, of which: Kanyameshi, Kafubu, Kipushi, Kamarenge and Lake Kamarenge. The study used the presses for the preparation of herbariums as well as multifunction probe for physico-chemical analyses in situ and a spectrophotometer (415 nm) for some parameters. For environmental observations, the analysis of sediments allows to assess the pollution level by metallic trace elements, which breaks the ecological balance of this aquatic ecosystem. The abundance indices of plant species in each waterbody were subjected to a Factorial Component Analysis in order to identify the distribution of the elements of the dominant plant associations. Data analysis was performed using PAST software. The findings showed 29 species distributed in 26 genera, 13 families and 11 orders. The Confirmatory Factor Analysis showed the distribution of plant groupings following a gradient of mineralization of the zones as well as that of abundance-dominance. Physico-chemical parameters influence the distribution of hydrophytes in wetlands. They constitute indicators of toxicity having an adverse consequence on the aquatic ecosystem for these metallic elements are not biodegradable. The more there is accumulation of dissolved metals in water, the more they create an environmental hazard.