Mycorrhizal status of some indigenous tree species in the Takamanda rainforest, South West Region, Cameroon

Abstract

A survey was carried out to determine the type of mycorrhizal association formed by trees within the different habitat types of the disturbed and undisturbed sites of the Takamanda rainforest. Forty-eight tree species of commercial and cultural importance were selected from the two sites for this study. Root samples were collected from a total of 327 individual trees belonging to the 48 species; they were cleared, stained and examined microscopically for mycorrhizal colonization and type. All the forty-eight species examined harbored one or more mycorrhizal structures, which ranged from arbuscules, intercellular hyphae, intracellular hyphae, vesicles, and Hartig net. Thirty-nine species formed exclusively arbuscular mycorrhiza (81.25%), two species; Uapaca guineensis and Angylocalyx oligophyllus formed ectomycorrhiza only (4.17%), while seven species Afzelia bipindensis, Baphia nitida, Anglylocalyx pynaertii, Cieba pentandra, Cylicodiscus gabunensis, Pterocarpus soyauxii and Terminalia ivorensis formed both ecto-and arbuscular mycorrhiza (14.58%). In both forest sites and habitat types, arbuscular mycorrhiza was the most represented among the tree species. In the undisturbed site and in the plain 68% of tree species sampled formed arbuscular mycorrhiza, 12% formed ectomycorrhiza, 16% formed dual mycorrhiza and 4% were non-mycorrhiza. On ridge top, 81.8% of the tree species formed arbuscular mycorrhiza, 13.6% formed ectomycorrhiza with 4.6% being dual mycorrhiza. On hilly slopes, 82.8% of the tree species formed arbuscular mycorrhiza, 13.8% formed ectomycorrhiza and 3.5% were dual mycorrhiza. In the disturbed site, 100% of the tree species sampled on the plain, formed arbuscular mycorrhiza. On the ridge top, 73.3% of the tree species sampled formed arbuscular mycorrhiza, 13.3% formed ectomycorrhiza and 13.3% were non mycorrhizal. On hilly slopes, 83.3% formed arbuscular mycorrhiza, 8.3% formed ectomycorrhiza and 8.3% were non-mycorrhizal. Mycorrhizas are important factors in Takamanda and must be taken into consideration, when designing management strategies for this forest.

Arbuscular mycorrhizal fungal diversity and association networks in African tropical rainforest trees

“…We detected a total of 194 AM fungal OTUs associated with the studied host tree species. While some of the tree species have been microscopically examined before for the presence of mycorrhizal structures (Onguene and Kuyper 2001; Bechem et al 2018), to our knowledge, this was the first time that their AM fungal communities were determined using molecular methods. The most abundant AM fungus genus was Glomus , aligning with previous studies on AM fungal composition in forest communities across the globe (Chen et al 2017; Sheldrake et al 2017, 2018; Boeraeve et al 2019a; Ji et al 2020; Touré et al 2020; Suárez et al 2023).…”

“…We detected a total of 194 AM fungal OTUs associated with the studied host tree species. While some of the tree species have been microscopically examined before for the presence of mycorrhizal structures (Onguene and Kuyper 2001;Bechem et al 2018), to our knowledge, this was the first time that their AM fungal communities were determined using molecular methods.…”