Ectomycorrhizal (ECM) fungi are widespread plant root symbionts in boreal forests, but
information is lacking on the fine scale distribution of roots and fungi in substrate patches of
different quality, including coarse woody debris (CWD).• Wood and soil cores were taken
systematically both horizontally and vertically through decayed logs and underlying soil
layers in a mixed forest. Root tips were counted and ECM fungi identified by morphotyping
and sequencing.• The abundance of root tips and ECM fungi was highly variable on a 5‐cm …

Numerous species of ectomycorrhizal (ECM) fungi coexist under the forest floor. To explore
the mechanisms of coexistence, we investigated the fine-scale distribution of ECM fungal
species colonizing root tips in the root system of Tsuga diversifolia seedlings in a subalpine
forest. ECM root tips of three seedlings growing on the flat top surface of rocks were sampled
after recording their positions in the root system. After the root tips were grouped by terminal-
restriction fragment length polymorphism (T-RFLP) analysis of ITS rDNA, the fungal species …