Exploration type of ectomycorrhizas assigned by identity of amplicon sequence variant

We traced roots from boles and confirmed their identity to be aspen by taste-testing. Sampled roots were put on ice after collection and transported to the University of Alberta the same day and stored at -20 °C prior to processing.

Aspen roots were thawed and washed free of adhering soil. Fine roots (< 1 mm in diameter) were retained, cut into 1 cm fragments, mixed thoroughly in a dish of water, and subsampled for DNA sequencing. Those sequences identified as ectomycorrhizal were then assigned to exploration types based on Agerer (2006).