| I assessed the impact of various harvesting practices (including those designed to emulate natural disturbances) on ectomycorrhizae associated with white spruce in northwestern Alberta, Canada. Treatments sampled included clear-cut, partial cut (with 20,50 and 75% live residual remaining), unharvested control and a burned stand. The percentage of active root tips, ectomycorrhizal richness and ectomycorrhizal diversity, observed in soil cores collected throughout the study site, all decreased with increasing harvesting intensity. Reductions in ECM biodiversity could be attributed to the sensitivity of late-stage ectomycorrhizae (e.g. Cortinarius spp., Lactarius spp., and Russula spp.). Harvesting practices that retained a percentage of permanent residual trees, either dispersed throughout the cutting unit (e.g. partial cutting) or in aggregated patches, were an effective means of maintaining ectomycorrhizal biodiversity. Mechanical site preparation, which is commonly used to improve the early performance of outplanted seedlings, significantly reduced the ectomycorrhizal status of planted white spruce seedlings. |
