[01] Nicole Ngutulu Toke, Department of Basic Sciences, Faculty of Agronomy, University of Gbado-Lite, Gbado-Lite, Democratic Republic of Congo. [02] Hippolyte Seya Wa Malale Nshimba, Department of Biology, Faculty of Science, University of Kisangani, Kisangani, Democratic Republic of Congo. [03] Da-Musa Yung Masens, Department of Biology, Faculty of Science, University of Kinshasa, Kinshasa, Democratic Republic of Congo. [04] Ruphin Djoza Djolu, Department of Environment, Faculty of Science, University of Gbado-Lite, Gbado-Lite, Democratic Republic of Cong. [05] Colette Masengo Ashande, Department of Environment, Faculty of Science, University of Gbado-Lite, Gbado-Lite, Democratic Republic of Cong. [06] Benjamin Zoawe Gbolo, Department of Environment, Faculty of Science, University of Gbado-Lite, Gbado-Lite, Democratic Republic of Cong. [07] Menga Munkolo Pisco, Department of Biology, Faculty of Science, University of Kinshasa, Kinshasa, Democratic Republic of Congo. [08] Koto-Te-Nyiwa Ngbolua, Department of Basic Sciences, Faculty of Agronomy, University of Gbado-Lite, Gbado-Lite, Democratic Republic of Congo; Department of Biology, Faculty of Science, University of Kinshasa, Kinshasa, Democratic Republic of Congo; Department of Environment, Faculty of Science, University of Gbado-Lite, Gbado-Lite, Democratic Republic of Cong.

The forests of the Democratic Republic of Congo (DRC) constitute one of the most complex terrestrial ecosystems in the world and are confronted with the erosion of the diversity they contain, with the concomitant loss of secondary metabolites with as yet unknown pharmaco-biological properties. Understanding their typology in order to facilitate their sustainable management is becoming a priority. The objective of the present study was to determine the structure and diversity of a heterogeneous forest stand in a few hydro-morphic sites of the Uma community forest (Tshopo, DRC). 281 individuals (representing 94 species) were recorded and grouped into 72 genus and 28 families. Plots 1 and 4 have more typical species (16 species and 13 species respectively). In all the plots inventoried, the species Petersianthus macrocarpus has a relative density of 6.4%, followed respectively by the species Dichostemma glaucescens (5.7%), Heisteria parvifolia and Peudospondias microcarpa (4.6% each), Cola griseiflora (4.3%) and Guarea cedrata and Pancovia harmisiana (3.2% each). The Euphorbiaceae family has a relative density of about 15.3%; followed by Fabaceae (13.97%); Meliaceae and Anacardiaceae (6.98%); Lecythidaceae and Myristicaceae (5.99% vs 6.65%. The species Piptadeniastrum africanum has a higher relative dominance (8.4%) than the species Petersianthus macrocarpus (6.9%); followed respectively by Peudospondias microcarpa (6.1%); Alstonia boonei (5.9%); Pachyelasma tessmannii (5.3%) and Ricinodendron heudellotii (5.1%) The Fabaceae family presents a relative dominance clearly superior to that of other families (36.7%). It is followed respectively by Euphorbiaceae (12.8%); Meliaceae (9.3%); Lecythidaceae (6.2%); Anacardiaceae (5.8%). Specific diversity was high in all the plots sampled: Simpson index (0.95-0.96); Shannon-w (3.35-3.42); equitability (0.91-0.96). The total basal area of this mixed forest formation is 26.7 m²/ha. The size distribution shows an inverted "J" pattern that gives an indication of a dynamic equilibrium situation, with dominance in the plot of individuals of the 10 cm dbh class that constitutes almost double those of the 20 cm class. The study showed that the populations are scattered over the hydromorphic soils in the mixed forest (t=6, 9364, dof=3, P-Value=0.006144<0.05%) making it difficult to rank them.

Floristic Survey, Diametric Structure, Biodiversity, Terrestrial Ecosystem, Democratic Republic of Congo

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