IMPACTS OF BEECH BARK DISEASE ON UNDERSTORY COMPOSITION IN

Beech bark disease was discovered in Michigan in 2000 and will likely kill at least 50 % of mature American beech trees. Our study was designed to determine how understory composition will be affected as beech bark disease spreads and intensifies throughout Michigan. We assessed the potential impact in forest stands with varying beech densities (low, moderate, and high) and abundance of Cryptococcus fagisuga (absent, light, and heavy). Variables were measured in 62 stands throughout the Upper and Lower Peninsulas of Michigan in 2002 and 2003. We found no significant difference in density of beech stems among stands. Significantly fewer sugar maple stems occurred in stands with heavy C. fagisuga than in stands with absent or light C. fagisuga. No current evidence suggests dense beech thickets will regenerate in stands impacted by beech bark disease in Michigan