On reclaimed mined sites recovery of fungal communities, especially ectomycorrhizal fungi (ECMF), and soil development can be slowed due to limited propagules of appropriate fungal species. Forestry and wildfire are intermediate disturbance types in which fungal propagules may be more readily present to recolonize soils and tree roots. In a 2013-2014 survey, we examined soil fungal communities in jack pine, white spruce and larch stands planted in 1983-1990 at the Gateway Hill mine reclamation site and in jack pine stands at a forestry site, which had been undisturbed, harvested, or lightly, partially or severely burned in a 2011 wildfire. We sampled forest floor and mineral soils from each stand and examined the relative abundance and diversity of fungi by Roche DNA pyrosequencing. We focused in 2014, on jack pine at two reclaimed stands and adjacent partially or severely burned forestry stands to examine fungal communities in mineral soil and roots and sporocarps on replicate samples along 50m transects.
Results/Conclusions
For the 2013-14 survey, tree species and physical space were major predictors of fungal composition and function in soils. Reclamation status still significantly described the distribution of fungal taxa when variance due to tree species and distance was removed. In the 2014 jack pine sampling, DNA analysis detected a total of 292 fungal taxa, 272 in soil and 257 in root samples, with richness and diversity greater in the reclamation vs. forestry site. In soil, 111 saprotroph taxa were detected, 21 preferentially in reclamation and 28 in forestry sites. In roots, 62 ECMF taxa were detected, 11 preferentially in reclamation and 17 in forestry sites. ECMF and saprophytic sporocarp richness was lowest in burnt jack pine, while greatest sporocarp abundance was in reclaimed jack pine. Sporocarp richness and abundance was higher in partially burnt vs. burnt jack pine stands.