Ectomycorrhizal fungal communities from soils and small mammal scats are equally diverse but differ in composition across urban reserves and native forest

Ectomycorrhizal fungi (EMF) are essential for forest health. In urban reserves, environmental stressors can affect both their plant hosts and the small mammals that disperse their propagules. We aimed to assess the response of EMF to urbanisation by comparing the diversity (i.e., Shannon diversity and richness) and composition of EMF communities in small mammal scats and soils from urban reserves to those in native forest sites in Sydney, Australia. We also tested the effects of season and small mammal species on EMF community diversity and composition in small mammal scats. Using ITS1 barcoding, we found that soils supported more diverse and distinct EMF communities than scats. EMF diversity was similar in urban reserves and native forest sites in both soils and scats, but community composition differed between the habitat types. In scats, EMF Shannon diversity was higher in autumn than in spring, while richness did not differ between seasons. Our comparison of the two most frequently captured mammals, Brown antechinus ( Antechinus stuartii ) and the Australian bush rat ( Rattus fuscipes ), revealed that antechinus scats had higher EMF Shannon diversity, but similar richness, than those of bush rats. EMF community composition was also different between these two small mammal species. Overall, our results indicate that urban reserves can act as important refugia for EMF, and that small mammals in these reserves may disperse a diverse pool of EMF.