Drivers of fungal succession during leaf litter decomposition in restored and secondary forests in tropical Andean forest

Assessing the diversity of organisms related to ecosystem, processes such as litter decomposition, and the factors influencing such diversity are useful indicators of the success of initiatives undertaken to restore ecosystems to a stable, functional state or their initial conditions. In this study, we evaluated the succession of decomposing fungal communities and their drivers at active restoration and native regeneration in a tropical Andean forest. We designed a litter decomposition experiment in which we manipulated the leaf litter quality using two plant species, Alnus acuminata (Betulaceae) and Hedyosmum bonplandianum (Chloranthaceae), which differ in the C:N ratio, and the soil fauna using two mesh sizes. Our results showed that the fungal communities were dominated by the phylum Ascomycota. Additionally, forest recovery strategies affected the fungal succession during the litter decomposition, with higher fungal richness and density recorded under active restorations. Further, the effect of litter quality and soil fauna on fungal community differed according to forest recovery strategies. The density of mycelial fungi propagules was only affected by soil fauna under active restoration. Species turnover was the main cause for the beta diversity of the fungal species under both forest recovery strategies. Our findings provide information on how the forest recovery strategies determine the richness, density, and composition of fungi associated with litter decomposition and how they mediate the effects of litter quality and soil fauna on the fungal community involved in the decomposition process.