Effects of selective cuts on the mycorrhizae of regenerating Betula alleghaniensis and Acer saccharum seedlings in two Quebec mixed deciduous forests

The mycorrhizae of younger (2- to 3-year-old) and older (5- to 12-year-old) yellow birch (Betula alleghaniensis Britton) and sugar maple (Acer saccharum Marsh.) seedlings and saplings were recorded from naturally regenerating plants in gaps created by selective cuts and compared with those of plants of comparable age growing in the undisturbed forest. The levels of ectomycorrhizal colonization and the diversity of ectomycorrhizal fungi (based on morphotyping) were recorded for yellow birch and the levels of colonization and the abundance of arbuscules, vesicles, and coils were reported for the vesicular-arbuscular mycorrhizae of sugar maples. Selective cutting had no negative effect on the mycorrhizal community structure of yellow birch and sugar maple. This may be because of the quick regeneration of the mycorrhizal hosts coupled with the minor levels of soil disruption and relatively small gap size at the study sites. Greater colonization levels in the gaps versus uncut areas were observed in the 2- to 3-year-old maples but not in the 2- to 3-year-old birch seedlings. The types of ectomycorrhizal fungi colonizing the roots of birch seedlings from the gaps did not differ from those in the uncut forest areas.