Intensive tropical land use changes correlate with massive shifts in soil fungal communities

Conversion of species rich rain forests to species poor monoculture plantations is regarded as the primary driver of species and ecosystem service loss in the tropics. Only little is known about impacts of logging on soil fungi, although they represent important key players as decomposers, mutualists and pathogens. Here, we investigated soil fungal community compositions in rain forests, jungle rubber agroforests and intensively managed oil palm and rubber plantations in two landscapes in Sumatra, Indonesia, using pyrosequencing. We hypothesized that the replacement of the hyperdiverse forest flora by non-endemic cash crops resulted in drastic diversity loss of soil fungal taxa. Instead, we found that rain forest conversion was associated with massive shifts in soil fungal community composition. Fungal community structures clustered according to land use type and loss of plant species. Network analysis revealed characteristic fungal genera significantly associated with different land use systems. Shifts in soil fungal community structure were particularly distinct among trophic groups with massive decreases in symbiotrophic and increases in saprotrophic and pathotrophic fungi in oil palm and rubber plantations in comparison with rain forests. In conclusion, conversion of rain forests and current plantation management restructures soil fungal communities towards enhanced pathogen pressure and thus, threatens ecosystem health functions.