Plant functional group drives the community structure of saprophytic fungi in a grassland biodiversity experiment

Davide Francioli,Sophie Q Van Rijssel,T E Anne Cotton,Aad J Termorshuizen,Liesje Mommer,Alexandra Weigelt,Jos M Raaijmakers,Alex J Dumbrell,Jasper Van Ruijven

doi:10.1007/s11104-020-04454-y

Abstract

AimsSaprophytic fungi are important agents of soil mineralization and carbon cycling. Their community structure is known to be affected by soil conditions such as organic matter and pH. However, the effect of plant species, whose roots provide the litter input into the soil, on the saprophytic fungal community is largely unknown.MethodsWe examined the saprophytic fungi in a grassland biodiversity experiment with eight plant species belonging to two functional groups (grasses and forbs), combining DNA extraction from plant roots, next-generation sequencing and literature research.ResultsWe found that saprophyte richness increased with plant species richness, but plant functional group richness was the best predictor. Plant functional group was also the main factor driving fungal saprophytic community structure. This effect was correlated with differences in root lignin content and C:N ratio between grasses and forbs. In monocultures, root traits and plant functional group type explained 16% of the variation in community structure. The saprophyte taxa detected in mixed plant communities were to a large extent subsets of those found in monocultures.ConclusionsOur work shows that the richness and community structure of the root-associated saprophytic fungi can largely be predicted by plant functional groups and their associated root traits. This means that the effects of plant diversity on ecosystem functions such as litter decomposition may also be predictable using information on plant functional groups in grasslands.

Highlights

Decomposition of plant tissue in terrestrial ecosystems regulates the transfer of carbon and nutrients to the soil (Chapin et al 2011)
Our work shows that the richness and community structure of the root-associated saprophytic fungi can largely be predicted by plant functional groups and their associated root traits
This means that the effects of plant diversity on ecosystem functions such as litter decomposition may be predictable using information on plant functional groups in grasslands

Summary

Introduction

Decomposition of plant tissue in terrestrial ecosystems regulates the transfer of carbon and nutrients to the soil (Chapin et al 2011). The saprophytic community is driven by the quantity of dying and decaying roots, which constitute more than half of the plant biomass (Berg and McClaugherty 2014b; Jackson et al 1996; Poorter et al 2012) and are a major organic matter input in soils (Lehmann and Kleber 2015; Silver and Miya 2001) It is well known from biodiversity studies in grasslands that root biomass (Cong et al 2015; Fargione et al 2007; Mueller et al 2013; Oram et al 2018; Ravenek et al 2014) and soil organic matter content (Cong et al 2014; Fornara and Tilman 2008; Lange et al 2015) increase with plant species richness. This increased quantity of substrate may affect the saprophytic fungal community

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Discussion

Conclusion