This poster outlines molecular analyses of soil fungi within the Bonanza Creek LTER over the last six years. We examined community structure in three studies in mixed upland, black spruce, and white spruce forests. While fungal diversity is extremely high, and we were unable to saturate diversity in one quarter gram of soil with 5000 clone sequences, we were nevertheless able to saturate diversity across the 12 black spruce sites after combing over 2000 soil cores and 30,000 clone sequences. We find that soil horizon is the factor by which fungal communities are most strongly structured, and that predictable turnover in upland fungal species occurred through succession. Communities from consecutive summers were not significantly different, suggesting considerable inter-annual stability, yet the community at a seasonal study site underwent significant changes within a year. In each study, mycorrhizal fungi dominated the community. Overall, our results point to considerable inter-annual resilience juxtaposed with narrow niche-partitioning and the capacity of individual taxa in these hyper-diverse communities to respond strongly to resource inputs and changes in other abiotic environmental parameters such as temperature. Our data double the cumulative total of fungal sequences in GenBank and together achieve a better picture of fungal communities here than any other ecosystem on earth at this time.