Root-associated fungal diversity in Central Africa’s most logged timber species (Aucoumea klaineana Pierre) suggests monodominance is independent of mycorrhizal associations

Aucoumea klaineana is the most important timber species in Central Africa, forming monodominant stands. While soil fungi are crucial for plant growth, their role in promoting monodominance and supporting suppressed, light-demanding trees remains underexplored. This study, the first to analyze the root mycobiota of A. klaineana , investigates fungal communities in monodominant stands and old-growth mixed forests in Gabon, and plantations in the DRC using ITS2 rDNA and SSU rRNA high-throughput sequencing. We identified high fungal diversity in both regions but found no "core mycobiota" across stand types or tree social status. Fungal communities varied significantly between stand types, emphasizing a context-dependent nature. Monodominance was not linked to ectomycorrhizal fungi (EcM), as no EcM OTUs were found in monodominant stands. While arbuscular mycorrhizal (AM) fungi exhibited high richness, their abundance was low, possibly due to the scarcity of arbuscules. No distinct fungal communities were found in suppressed trees. These findings challenge the assumed link between EcM associations and monodominance in A. klaineana , suggesting alternative mechanisms, such as root grafting, may influence stand dynamics. This study provides a foundation for future research on the belowground strategies that contribute to the persistence and sustainable management of A. klaineana .