Natural ¹³C and ¹⁵N abundance of field‐collected fungi and their ecological implications

Abstract

The natural abundance of 13 C and 15 N was measured in basidiocarps of at least 115 species in 88 genera of ectomycorrhizal, wood‐decomposing and litter‐decomposing fungi from Japan and Malaysia. The natural abundance of 13 C and 15 N was also measured in leaves, litter, soil and wood from three different sites. 15 N and 13 C were enriched in ectomycorrhizal and wood‐decomposing fungi, respectively, relative to their substrates. Ectomycorrhizal and wood‐decomposing fungi could be distinguished on the basis of their δ 13 C and δ 15 N signatures. Although there was high variability in the isotopic composition of fungi, the following isotope‐ enrichment factors (ε, mean±SD) of the fungi relative to substrates were observed: ε ectomycorrhizal fungi/litter = 6.1±0.4‰ 15 N ε ectomycorrhizal fungi/wood = 1.4±0.8‰ 13 C ε wood‐decomposing fungi/wood = −0.6±0.7‰ 15 N ε wood‐decomposing fungi/wood = 3.5±0.9‰ 13 C The basis of isotope fractionation in C metabolism from wood to wood‐decomposing fungus is discussed.