The ecology of Armillaria sinapina in mixedwood forests of north-western Alberta, Canada

The purpose of this study was to examine the ecology of Armillaria sinapina in boreal mixedwood forests in north-western Alberta. Nine 40 x 40 m plots were established in stands that ranged from 7.2% to 92% broadleaf trees, snags, and stumps. Using logistic regression, I determined which variables best predicted the presence of A. sinapina in trees, snags, stumps, downed woody material, forest floor cores, and trap-logs. Second, I described the spatial point pattern of the fungus infecting trees, snags, and stumps. The main results were that A. sinapina preferred broadleaf substrates over coniferous substrates. Dead coniferous trees were more likely to be infected by A. sinapina . This result suggests that A. sinapina may be playing a role in the death of coniferous trees. The spatial point pattern of infected trees, snags, and stumps reflected the underlying spatial point pattern of the host trees.