Fungal mycelium is increasingly recognized as a central component of soil biogeochemical cycling, yet our current understanding of the ecological controls on fungal necromass decomposition is limited to single sites and vegetation types. By deploying common fungal necromass substrates in a temperate oak savanna and hardwood forest in the midwestern USA, we assessed the generality of the rate at which high- and low-quality fungal necromass decomposes; further, we investigated how the decomposer ‘necrobiome’ varies both across and within sites under vegetation types dominated by either arbuscular or ectomycorrhizal plants. The effects of necromass quality on decay rate were robust to site and vegetation type differences, with high-quality fungal necromass decomposing, on average, 2.5 times faster during the initial stages of decay. Across vegetation types, bacterial and fungal communities present on decaying necromass differed from bulk soil microbial communities and were influenced by necromass quality. Moulds, yeasts and copiotrophic bacteria consistently dominated the necrobiome of high-quality fungal substrates. Synthesis. We show that regardless of differences in decay environments, high-quality fungal substrates decompose faster and support different types of decomposer micro-organisms when compared with low-quality fungal tissues. These findings help to refine our theoretical understanding of the dominant factors affecting fast cycling components of soil organic matter and the microbial communities associated with rapid decay.
Bibliographical noteFunding Information:
We thank Christopher Fernandez and Craig See for their input during project conceptualization. We would also like to thank Jeff White for providing lab space to perform DNA extractions, Megan Midgley for establishing the plots at Moores Creek, Amanda Certano for preparing the HTS library, and Katie Scheiner for assistance with necromass chemical characterization. We are grateful to the members of the Kennedy and Phillips labs for their feedback as well as the constructive suggestions of two anonymous reviewers for earlier drafts of this manuscript. Funding for this work was provided by the U.S. Department of Energy Office of Biological and Environmental Research, Terrestrial Ecosystem Science Program (Award# DE‐SC0016188) to R.P.P. and University of Minnesota Undergraduate Research Opportunity Program grant to E.A.
© 2020 British Ecological Society
- fungal hyphae
- fungal mycelium
- mycorrhizal type
- oak savanna
- temperate forest