Freshwater diatoms in the Democratic Republic of the Congo: a historical overview of the research and publications

Volume: 136Start Page: 107-12

Uses and importance of wild fungi: traditional knowledge from the Tshopo province in the Democratic Republic of the Congo

Abstract Background Wild mushrooms constitute an important non-timber forest product that provides diverse substances and services, especially food and income for local communities from many parts of the world. This study presents original ethnomycological documentation from the dense rainforests of the Democratic Republic of the Congo. Methods Ethnomycological surveys were made within local communities near the biosphere reserve of Yangambi and the Yoko forest reserve. The interviews involved 160 informants from six different ethnic communities (Bakumu, Turumbu, Topoke, Lokele, Ngelema, and Ngando). Specific reported use (RU), the relative importance (RI), and the cultural significance (CS) of wild edible fungi were calculated using quantitative data from enquiries. Results The people from Tshopo use 73 species of wild mushrooms either for food (68 species), as medicine (9 species), in a recreational context (2 species), or related to myths and beliefs (7 species). Women are more involved in harvesting and are the main holders of cultural aspects related to fungi. The results show that knowledge of useful mushrooms differs between ethnic groups. The Ngando people have the highest ethnomycological expertise, which is expressed in their extensive cultural and practical use of fungi. Pleurotus tuber-regium is the most important species (MCSI = 1.9 and p value < 2.2e−16) as it is being used for food, as a medicine, and more. Daldinia eschscholtzii is the most important (MUI = 0.86 and p value < 2.2e−16) for medicinal applications, while Schizophyllum commune, Auricularia cornea, A. delicata, Marasmius buzungolo, and Lentinus squarrosulus are mostly appreciated for food. The latter five species are all wood-decaying saprotrophs. Conclusion Despite the presence of edible ectomycorrhizal taxa in the dense rainforests of Tshopo, local people only seem to have an interest in saprotrophic taxa. Some mushroom pickers deliberately cut down host trees to promote the development of saprotrophic taxa. Inducing forest degradation is considered beneficial as it promotes the development of saprotrophic taxa. The domestication of locally appreciated saprotrophic lignicolous fungi is proposed as a mitigating measure against fellings

Leaf traits of understory woody species in the Congo Basin forests changed over a 60-year period

Background and aims – While tropical forests play an important role in carbon sequestration, they are assumed to be sensitive to rising temperatures and prolonged drought. Plant functional traits are useful for understanding and predicting the effects of such changes in plant communities. Here, we analyse the variation of leaf traits of understory woody species of the Congo Basin rainforests over a 60-year period using herbaria as tools and we verify if this variation is potentially related to recent climate change. Material and methods – Leaves of five shrub species were collected in 2019–2022 in Congolese old-growth forests (Yangambi Biosphere Reserve, DR Congo) from different positions on the shrub. These leaves were compared with herbarium specimens collected in the same area before 1960. For both periods, we assessed leaf size, specific leaf area, stomatal size, and stomatal density for all species. Key results – The variability of the functional traits of the understory woody species are independent of the position of the leaves in the crown. This allows for the use of historic herbarium collections for trait analyses on tropical understory shrubs. The traits of the recently collected leaves were notably different from the traits of herbarium leaves collected in pre-1960: recent leaves were significantly larger, had a higher Specific Leaf Area, a smaller stomata pore length, and, apart from Coffea canephora, showed a lower stomatal density. Conclusion – The difference in traits over time is probably related to the increase in temperature and to atmospheric CO2 concentration, as the average temperature at Yangambi over the past 60 years has shown an upward trend consistent with global increasing CO2 levels, while the average annual rainfall has remained unchanged. Our results provide a first insight into the response of forest species to climate change in the Congo Basin forests, and on how the understory species and the ecosystem will react in the long term, when the temperature further increases

Estimation de la biomasse aérienne par utilisation des grands arbres dans la réserve forestière de Yoko

Depuis l’avènement du mécanisme REDD+, l’estimation précise de la biomasse ligneuse aérienne est au centre des enjeux environnementaux actuels. La majorité des équations allométriques disponibles ont été établies au moyen de variables dendrométriques issues de méthodes destructives et incluant, hormis la hauteur et la densité de bois, un spectre limité de diamètre à hauteur de poitrine. Cette étude a pour objectif de tester une méthode non destructive de mesure de variables dendrométriques en vue d’estimer la biomasse aérienne en forêt tropicale dense humide, à partir des équations allométriques les plus adaptées pour une forêt dense humide sur terre ferme au nord-est de la République démocratique du Congo. Les résultats indiquent que les arbres émergents stockent à eux seuls 41 % de la biomasse aérienne de l’ensemble de la placette. Ce pourcentage augmente jusqu’à 67 % lorsqu’on regroupe les espèces dominantes et émergentes. Cette étude montre aussi qu’il est possible d’estimer le diamètre à partir de la couronne de l’arbre mesurée sur des images satellites à très haute résolution spatiale pour des espèces émergentes et dominantes. De très fortes corrélations entre le diamètre mesuré sur le terrain et le diamètre de la couronne mesurée par satellite ont été obtenues pour les espèces Prioria oxyphylla (Harms) Breteler et Pericopsis elata (Harms) Van Meeuwen, tandis que cette corrélation était très satisfaisante pour les espèces Entandrophragma spp., Piptadeniastrum africanum (Hook.f.) Brenan et Albizia gummifera (J.F. Gmel.) C.A. Sm