Identification of invasive alien species and assessment of ecological factors in the pool Malebo in Kinshasa, Democratic Republic of the Congo

Abstract

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.