Rapid incorporation of carbon from ectomycorrhizal mycelial necromass into soil fungal communities

► First application of DNA-SIP to trace carbon from decomposing mycorrhizal mycelium. ► Carbon from ectomycorrhizal necromass is incorporated into fungal DNA within 7 days. ► 13C NMR analyses suggests dead mycelium is rapidly turned over. ► DNA-SIP revealed a dynamic community of functionally active soil fungi. ► Dead mycelium is an important source of labile carbon for soil microorganisms.