Search for a command to run...
Abstract In temperate European forests, soil fungal communities, dominated by saprotrophic and ectomycorrhizal (ECM) species, represent almost 25% of soil organic carbon (C) in the soil. However, the decomposition dynamics of fungal necromass, the bioavailability of its associated elements and its role in soil C stabilisation remain poorly understood. We investigated how intrinsic chemical properties—particularly melanin content, nitrogen (N) and phosphorus (P) levels—influence the microbial decomposition of fungal necromass in a temperate oak forest. We compared two types of fungal necromass: Laccaria bicolor (low melanin content) and Fomitiporia robusta (high melanin content). We monitored mass loss, stoichiometric ratios and microbial enzymatic activity over a six‐month period in soil. Additionally, we analysed bacterial and fungal community structures via DNA metabarcoding, and estimated microbial biomass using qPCR during the decomposition process. The highly melanised necromass showed limited mass loss and reduced enzymatic activity, indicating greater recalcitrance. Contrasting C:P and C:N ratio profiles during the decomposition of the two types of substrate suggest that melanin plays a key role in the decomposition dynamics of the fungal necromass, while P and N do not appear to be determining factors in this process. Copiotrophic bacteria and saprotrophic fungi dominated the early stages of decomposition, while in later stages, oligotrophic bacteria and certain ECM genera became dominant. Our findings confirm that fungal necromass decomposition is strongly influenced by its intrinsic chemical properties, and particularly by its melanin content. This substrate constitutes a unique ecological niche, shaping the succession of specialised microbial guilds (i.e. the fungal necrobiome). Finally, our results highlight the significant abundance of certain fungal guilds, such as ECM fungi, raising questions about the potential role of these symbiotic fungi in the decomposition of fungal necromass or their passive, but massive, colonisation of this soil micro‐niche. Read the free Plain Language Summary for this article on the Journal blog.