Plant interaction traits determine the biomass of arbuscular mycorrhizal fungi and bacteria in soil

Abstract

Plant-arbuscular mycorrhizal fungal (AMF) mutualisms play key roles in the biodiversity and productivity of ecosystems. Yet we have limited understanding of the functional roles of plants as AMF generalists or specialists, and the consequences of these plant interaction traits for soil ecosystems are virtually unknown. We grew eight pasture plant species under two experimental conditions and determined their root AMF communities by sequencing. We determined plant species interaction traits with AMF using a set of numeric and phylogenetic -, {beta}- and {gamma}-diversities and characterized plant species relative interaction generalism for AMF. We used lipid analysis of rhizosphere soils and Bayesian modelling to explore how host interaction traits affected carbon allocation to AMF and bacteria. Plant interaction traits for AMF appear to be stable despite large variation in edaphic conditions and AMF pools. We show that host interaction generalism was associated with opposite patterns of bacterial and AMF biomass; the phylogenetic diversity of host interactions was positively associated with AMF biomass whereas the richness of host interactions was negatively associated with bacterial biomass in rhizosphere soils. Explicit consideration of plant interaction niches may enhance understanding of how changes in biodiversity affect ecosystem carbon cycling. Open research statementThis publication does not use novel code, and the bioinformatic and statistic pipelines for this manuscript will be made available at https://github.com/NLewe/Bayes-interaction-niche. Raw data will be made available at NCBI as BioProject: PRJNA997080