title: Top-down control of soil fungal community composition by a globally distributed keystone consumer.
abstract: The relative contribution of top-down and bottom-up processes regulating primary decomposers can influence the strength of the link between the soil animal community and ecosystem functioning. Although soil bacterial communities are regulated by bottom-up and top-down processes, the latter are considered to be less important in structuring the diversity and functioning of fungal-dominated ecosystems. Despite the huge diversity of mycophagous (fungal-feeding) soil fauna, and their potential to reverse the outcomes of competitive fungal interactions, top-down grazing effects have never been found to translate to community-level changes. We constructed soil mesocosms to investigate the potential of isopods grazing on cord-forming basidiomycete fungi to influence the community composition and functioning of a complex woodland soil microbial community. Using metagenomic sequencing we provide conclusive evidence of direct top-down control at the community scale in fungal-dominated woodland soil. By suppressing the dominant cord-forming basidiomycete fungi, isopods prevented the competitive exclusion of surrounding litter fungi, increasing diversity in a community containing several hundred fungal species. This isopod-induced modification of community composition drove a shift in the soil enzyme profile, and led to a restructuring of the wider mycophagous invertebrate community. We highlight characteristics of different soil ecosystems that will give rise to such top-down control. Given the ubiquity of isopods and basidiomycete fungi in temperate and boreal woodland ecosystems, such top-down community control could be of widespread significance for global carbon and nutrient cycling.
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Cardiff CF10 AX, United Kingdom. thomas.crowther@yale.edu
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Crowther
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Cardiff CF10 AX, United Kingdom.
authors.forename: David W G
authors.initials: DW
authors.lastname: Stanton
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Cardiff CF10 AX, United Kingdom.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Thomas
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Cardiff CF10 AX, United Kingdom.
authors.forename: A Donald
authors.initials: AD
authors.lastname: A'Bear
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Cardiff CF10 AX, United Kingdom.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hiscox
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Cardiff CF10 AX, United Kingdom.
authors.forename: T Hefin
authors.initials: TH
authors.lastname: Jones
authors.affiliation: Laboratory of Environmental Microbiology, Institute of Microbiology of the ASCR, v.v.i., Videnská 1083, 14220 Praha 4, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Vorísková
authors.affiliation: Laboratory of Environmental Microbiology, Institute of Microbiology of the ASCR, v.v.i., Videnská 1083, 14220 Praha 4, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Baldrian
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Cardiff CF10 AX, United Kingdom.
authors.forename: Lynne
authors.initials: L
authors.lastname: Boddy
mesh_terms: D000818:Animals; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005658:Fungi / Q000145:classification / Q000201:enzymology* / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D033321:Isopoda / Q000502:physiology*; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D005656:Fungal Proteins; D012987:Soil