Elevated CO2 impacts ectomycorrhiza-mediated forest soil carbon flow: fungal biomass production, respiration and exudation

Large quantities of carbon are exchanged between terrestrial ecosystems and the atmosphere, and extensive research efforts are made to understand carbon cycling and the impact of elevated atmospheric CO2 levels. The response of soils to increased carbon availability is largely driven by root associated ectomycorrhizal fungi in forest ecosystems, since they partition host derived carbon belowground. In this review I examine how CO2 enrichment affects ectomycorrhizal fungal biomass production, exudation, respiration, soil carbon fluxes, and other soil microbes, and the importance of the fungal species in these responses. I briefly discuss the significance of CO2 alterations in the mycorrhizal symbiosis in the context of consequences for carbon sequestration, and present research priorities.