Ectomycorrhizal fungal (EMF) communities vary among microhabitats, supporting a dominant role for deterministic processes in EMF community assemblage. EMF communities also differ between forest and clearcut environments, responding to this disturbance in a directional manner over time by returning to the species composition of the original forest. Accordingly, we examined EMF community composition on roots of spruce seedlings planted in three different microhabitats in forest and clearcut plots: decayed wood, mineral soil adjacent to downed wood, or control mineral soil, to determine the effect of retained downed wood on EMF communities over the medium and long term. If downed and decayed wood provide refuge habitat distinct from that of mineral soil, we would expect EMF communities on seedlings in woody habitats in clearcuts to be similar to those on seedlings planted in the adjacent forest. As expected, we found EMF species richness to be higher in forests than clearcuts (P ≤ 0.01), even though soil nutrient status did not differ greatly between the two plot types (P ≥ 0.05). Communities on forest seedlings were dominated by Tylospora spp., whereas those in clearcuts were dominated by Amphinema byssoides and Thelephora terrestris. Surprisingly, while substrate conditions varied among microsites (P ≤ 0.03), especially between decayed wood and mineral soil, EMF communities were not distinctly different among microhabitats. Our data suggest that niche partitioning by substrate does not occur among EMF species on very young seedlings in high elevation spruce-fir forests. Further, dispersal limitations shape EMF community assembly in clearcuts in these forests.
Funding for this project was provided by a Discovery Grant from the Natural Sciences and Engineering Research Council, and by the Forest Science Program of the British Columbia Forest Investment Account to M.J. J.W. acknowledges support from UBC Okanagan and the Province of BC for scholarships. We thank Alan Vyse for safe access to the field site, MaryAnn Olson and
Fawn Ross for extensive fieldwork, and Valerie Ward for unsurpassed assistance in the field and laboratory. This manuscript was greatly improved with the help of constructive comments from two anonymous reviewers.
Conflict of interest The authors declare that no financial conflict of
- DNA, Fungal
- Microbial Consortia
- Plant Roots
- Soil Microbiology