The potential research outputs of a European-wide survey of mycorrhizal fungi in biomonitoring plots. Rectangles represent a research effort, ovals indicate a research output and diamonds indicate an instance when data gathered from ICP Forest plots would enhance research efforts. Phase 1: Whilst the primary research achievement would be European-wide distributional data for mycorrhizal fungi, a number of immediate secondary research outputs would also be generated. Combining the mycorrhizal fungal survey data with environmental data would be critical to the development of Phase 2, which focuses on ecologically-relevant and hypothesis-driven research at smaller scales. Combining these data with tree health and environmental data can pinpoint key links between shifts in mycorrhizal fungal community composition and forest ecosystem health. ICP: The International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests.