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

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. Key words: Arbuscular mycorrhiza, ectomycorrhiza, Takamanda forest.