XVI International Botanical Congess

The mycorrhizae of yellow birch and sugar maple saplings growing in managed forests were analyzed. Saplings of each species were sampled from 2 forests in Quebec from gaps of different sizes and ages. The morphotypes of ectomycorrhizae(ECM) on the roots of the birch and the colonization of maple roots by arbuscules, vesicles, and coils were quantified. Seasonal patterns of colonization in maples collected from 10- and 5-yr old gaps of all sizes were similar. Mycorrhizal colonization and morphotype diversity of yellow birch was unaffected by gap size and age. In recent cuts, colonization increased in maple roots throughout the season. In October there were more arbuscules and coils in saplings from the gaps, vs those from uncut areas. ECM colonization of birches increased with season, but was unaffected by gap size.