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

In many parts of the world, wild mushrooms constitute important non-timber forest product (NTFP) [1‐4]. They provide diverse substances and services to local communities, especially as a source of food and income [4‐7]. Nutritionally, they are an important source of proteins, vitamins, fats, carbohydrates, amino acids, and minerals [8, 9], i.e., a worthy alternative or substitute for meat and fish [6, 8]. In various cultures, mushrooms are widely used as medicine, but also in a recreational context and for myths and beliefs [10].

Several studies note that local mushroom knowledge varies with people’s cultures and beliefs [10‐13]. Within local communities, the traditional knowledge is passed on from one generation to another. For local communities, it is often the only, albeit fragile but effective, way of safeguarding information concerning useful fungi [11‐13]. Traditional knowledge linked to fungal taxa can be recorded and allows to evaluate its use-value for a specific local community [11, 14]. The analysis of use-value provides information about cultural differences between communities [11, 14].

Scientists recognize that assessing the various uses of wild fungi by local people is the key towards a better valorization of services provided by wild useful fungi [7]. This also enables to better elaborate participative management and conservation plans [15]. Several scientists [15] have reported that pressure caused by mushrooms pickers, either deliberate by fellings or non-deliberate by trampling, induces forest degradation. Forest conservation strategies aiming at a sustainable mushroom harvest largely depend on the targeted fungal ecological group (saprotrophic and/or ectomycorrhizal). While ectomycorrhizal taxa constitute the most important group of useful fungi in miombo woodlands and open forests [16, 17], the saprotrophic taxa seem more important in rain and montane forest types [3, 18, 19]. Cultivation of locally used fungi is considered as a mitigating measure against deliberate fellings for the promotion of some useful saprotrophic taxa. An ethnomycological survey is thereby important before the cultivation starts, to collect and document about the locally used fungal species.

Documentation related to the traditional use of mushrooms is scarce [3, 10, 12, 13]. Within local communities, oral transmission is often the only way to transfer local knowledge [12, 13]. The lack of documentation regarding wild edible fungi and the need to conserve it through oral transmission makes local mycological knowledge fragile [17]. Due to a continuing exodus of younger people to new areas or the bigger cities, local communities gradually lose an important part of their traditional knowledge, particularly about mushrooms [12, 13, 17]. There is a genuine need to record and document local traditional knowledge about wild edible and useful fungi.

The Tshopo province (Democratic Republic of the Congo) is part of the central African Congo basin and its rainforests are host to a wealth of edible and useful fungal species [3]. In this region, more than 80% of the population lives outside the cities [20, 21] and depend for their livelihoods on wild natural resources, including mushrooms. This study aims to fill the gap in ethnomycological knowledge available from the DR Congo by delivering original data obtained from the communities living around the Man-and-Biosphere Reserve of Yangambi and the Yoko Forest Reserve.

In total, 160 informants (72 women, 88 men) were interviewed. The age of the informants ranged from 16 to 72 years. From the entire sample, the Turumbu people were the most dominant tribe with 67 informants (41.9%), while the rest were Topoke (17.5%), Lokele (15%), Ngelema (10%), Bakumu (8.8%), and Ngando (6.9%). The entire pool of informants recognized 73 species of wild fungi as useful (Table 1).

Four categories of usage were reported (Fig. 2): food, medicinal, belief and myth, and recreational.

Among the 73 fungal species reported as useful, 68 are mentioned as edible, only 9 are reported as medicinal, 7 are reported as mythical, and 2 are used in a recreational context. Some edible taxa such as Schizophyllum commune and Pleurotus tuber-regium were used both for food and medicine. Figure 3 shows the distribution of edible fungi within functional groups.

The reported edible species belong to 3 fungal functional groups. The most commonly eaten and appreciated species belong to the saprotrophs (36 species), most of these within the Marasmiaceae. Among ectomycorrhizal fungi, the Cantharellaceae and Russulaceae were the most represented (11 species each).

The study shows that local people from Tshopo, regardless of their age, use wild mushrooms either for food, for medicine, for recreation, or in relation to certain beliefs or myths. This result concurs with many other studies [1, 13, 43]. The study also reports that mushroom knowledge is differently shared within the ethnic groups, as well as age and gender classes. Younger informants know only common edible taxa and a few species useful to make toys with. The older generations, however, handle more species and are skilled with medicinal and mythical uses of fungi. Women are generally more involved in mushroom harvesting and possess very high knowledge on edible taxa as well as their wider cultural significance. This observation is in line with the findings of several other authors [10, 12, 17]. They respectively found that in rural areas in Benin, Zambia, and Tanzania, women and children constitute the most important group of mushroom pickers and sellers. In West Africa, DSRP and PNUD [19, 43] found that basic ethnomycological knowledge crosses gender, age groups, and occupation categories.

Several other studies [1, 12, 13] have shown that people lose part of their mycological knowledge when moving to a new area. However, the Ngando people who came from the former province of Equateur still provide a lot of information about mushrooms, including cultural significance. The high cultural significance of Ngando people on mushroom uses may be explained by the fact that Ngando people are a nearly autarkic community, i.e., living remotely in forest areas and mainly using natural resources for their subsistence. This comment is supported by numerous scientists [44] who reported that Ngando people use mainly wild useful plants for subsistence because of their localization far inside forests. Because of taboos, e.g., not eating any Auricularia and Russula species (“Sengwa” = inedible fungi), the Kumu people use far less mushrooms. Taboos on mushrooms consolidate mycophobia and negatively affect the people’s interest in mushroom consumption.

Wood-decomposing fungi such as Schizophyllum commune, Auricularia spp., Marasmius buzungolo, and Lentinus squarrosulus are the most eaten taxa in the Tshopo province. Several scientists [3, 6, 19, 43] have mentioned a higher consumption interest for saprotrophic species in rainforests. In central African rainforests for example, the saprotrophic fungi constitute the most consumed group [3]. According to several other ethnomycological studies [7, 9, 16, 17, 19, 45], people from miombo forests and savannah woodlands eat significantly more ectomycorrhizal fungi than saprotrophic ones. The main reason for this is that these forests are prone to bushfires that significantly reduce the amount of substrate available for saprotrophs to develop.

Concerning the medicinal use, we report nine species (Auricularia delicata, Cookeina speciosa, Daldinia eschscholtzii, Cotylidia aurantiaca, Ganoderma sp., Pleurotus tuber-regium, Lentinus velutinus, Pycnoporus sanguineus, and Schizophyllum commune) possibly providing medicinal contents. Several studies [1, 46] reported that Ganoderma species are the most valuable medicinal fungi worldwide. Even in modern medicine, these taxa are considered genuinely interesting [46]. The reported medicinal use of Pycnoporus sanguineus, i.e., to treat ear inflammation, corresponds with the findings of numerous scientists [47] who found that P. sanguineus is used to treat sores in Malaysia. Moreover, several other scientists [47‐49] have reported the medicinal property of Pleurotus tuber-regium. According to this study, Pleurotus tuber-regium is also used to stop children from bed watering while in Malaysia local people use Xylaria polymorpha for this purpose [47].

In addition, the findings report several mythical and belief uses of mushrooms from Tshopo. Pleurotus tuber-regium is used to drive away destructive birds from rice fields. Phallus indusiatus is used to induce discord between people while Cantharellus densifolius and Lentinus squarrosulus bring luck. The mythical use of wild fungi or plants has been reported by several studies [40, 43, 49, 50]. From Yoruba people in western Nigeria, Pleurotus tuber-regium is considered as the crops of divine gods and used to overpower evil spirits [49]. In Madagascar, the species is used against strong wind, and used by women to get in funerary room without fear of death [49]. These reports of mythical uses might confirm the hallucinogenic effects of some mushrooms mentioned by several previous studies [43, 49, 50].

Pleurotus tuber-regium is reported the most useful and important fungus as it plays a key role in social life and culture of people from Tshopo in the Democratic Republic of Congo. It is used as food, as medicine, for recreational aspect, and for myth and belief. The mythical and religious purposes might confirm the hallucinogenic effects of fungi on people. However, it makes belief that spiritual interaction may exist between wild fungi and people. Saprotrophic fungi, including many wood-decaying taxa, are the most consumed and appreciated because of their taste. Some mushroom pickers deliberately cut down host trees to promote mushroom development, eventually promoting or boosting forest degradation. For sustainable use of natural forests and to mitigate the harvest-related pressure on natural habitats, the cultivation of the most useful and appreciated saprotrophic fungi (value MCSI above 1) such as Auricularia cornea, Marasmius buzungolo, Pleurotus tuber-regium, Lentinus squarrosulus, and Schizophyllym commune is proposed. However, the latter species should be worth discarded from culturing as it is known to cause the severe “Schizophyllum disease” in both healthy and immunodeficient people [51, 52].