title: Quantitative assessment of the differential impacts of arbuscular and ectomycorrhiza on soil carbon cycling.
abstract: A significant fraction of carbon stored in the Earth's soil moves through arbuscular mycorrhiza (AM) and ectomycorrhiza (EM). The impacts of AM and EM on the soil carbon budget are poorly understood. We propose a method to quantify the mycorrhizal contribution to carbon cycling, explicitly accounting for the abundance of plant-associated and extraradical mycorrhizal mycelium. We discuss the need to acquire additional data to use our method, and present our new global database holding information on plant species-by-site intensity of root colonization by mycorrhizas. We demonstrate that the degree of mycorrhizal fungal colonization has globally consistent patterns across plant species. This suggests that the level of plant species-specific root colonization can be used as a plant trait. To exemplify our method, we assessed the differential impacts of AM : EM ratio and EM shrub encroachment on carbon stocks in sub-arctic tundra. AM and EM affect tundra carbon stocks at different magnitudes, and via partly distinct dominant pathways: via extraradical mycelium (both EM and AM) and via mycorrhizal impacts on above- and belowground biomass carbon (mostly AM). Our method provides a powerful tool for the quantitative assessment of mycorrhizal impact on local and global carbon cycling processes, paving the way towards an improved understanding of the role of mycorrhizas in the Earth's carbon cycle.
authors.affiliation: Systems Ecology, Department of Ecological Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands.|Environmental Biology, Institute of Environmental Sciences, Leiden University, Einsteinweg 2, 2333CC, Leiden, the Netherlands.|Louis Bolk Instituut, Hoofdstraat 24, 3972, LA Driebergen, the Netherlands.
authors.forename: Nadejda A
authors.initials: NA
authors.lastname: Soudzilovskaia
authors.affiliation: Plant-Soil Interactions, Institute for Sustainability Sciences, Agroscope, 8046, Zürich, Switzerland.|Institute of Evolutionary Biology and Environmental Studies, University of Zürich, 8057, Zürich, Switzerland.|Plant-Microbe Interactions, Institute of Environmental Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, the Netherlands.
authors.forename: Marcel G A
authors.initials: MG
authors.lastname: van der Heijden
authors.affiliation: Systems Ecology, Department of Ecological Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands.
authors.forename: Johannes H C
authors.initials: JH
authors.lastname: Cornelissen
authors.affiliation: Soil Science Department, Moscow State University, 119991, Moscow, Russia.
authors.forename: Mikhail I
authors.initials: MI
authors.lastname: Makarov
authors.affiliation: Department of Geobotany, Moscow State University, 119991, Moscow, Russia.
authors.forename: Vladimir G
authors.initials: VG
authors.lastname: Onipchenko
authors.affiliation: Soil Science Department, Moscow State University, 119991, Moscow, Russia.
authors.forename: Mikhail N
authors.initials: MN
authors.lastname: Maslov
authors.affiliation: Teberda State Biosphere Reserve, 369210, Teberda, Russia.
authors.forename: Asem A
authors.initials: AA
authors.lastname: Akhmetzhanova
authors.affiliation: Environmental Biology, Institute of Environmental Sciences, Leiden University, Einsteinweg 2, 2333CC, Leiden, the Netherlands.
authors.forename: Peter M
authors.initials: PM
authors.lastname: van Bodegom
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D057486:Carbon Cycle; D025282:Mycelium; D038821:Mycorrhizae / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology; D010944:Plants / Q000378:metabolism / Q000382:microbiology; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D013559:Symbiosis
chemical_list: D012987:Soil; D002244:Carbon
keywords: arbuscular mycorrhizal (AM) fungi; ectomycorrhizal (EM) fungi; extraradical mycelium; intraradical mycelium; plant trait; root length colonization; root tips; sub-arctic ecosystems