Data from: Environment and host as large-scale controls of ectomycorrhizal fungi

Explaining the large-scale diversity of soil organisms that drive
biogeochemical processes—and their responses to environmental change—is
critical. However, identifying consistent drivers of belowground diversity
and abundance for some soil organisms at large spatial scales remains
problematic. Here we investigate a major guild, the ectomycorrhizal fungi,
across European forests at a spatial scale and resolution that is—to our
knowledge—unprecedented, to explore key biotic and abiotic predictors of
ectomycorrhizal diversity and to identify dominant responses and
thresholds for change across complex environmental gradients. We show the
effect of 38 host, environment, climate and geographical variables on
ectomycorrhizal diversity, and define thresholds of community change for
key variables. We quantify host specificity and reveal plasticity in
functional traits involved in soil foraging across gradients. We conclude
that environmental and host factors explain most of the variation in
ectomycorrhizal diversity, that the environmental thresholds used as major
ecosystem assessment tools need adjustment and that the importance of
belowground specificity and plasticity has previously been
underappreciated.