Fifty-year impacts of the beech bark disease in the Bartlett Experimental Forest, New Hampshire.

摘要

Records from the early 1950s on the Bartlett Experimental Forest in New Hampshire, USA showed that the percentage of American beech (Fagus grandifolia) trees infected with heavy beech scale (Cryptococcus fagisuga) and Nectria coccinea var. faginata ranged from 80 to 90%. An inventory of beech bark disease conditions in three stands in 2004 showed that an older, uneven-aged stand managed by individual tree selection for 50 years had over 70% of the basal area in clean- (or disease-free) and rough-barked trees - trees that showed resistance or partial resistance to the disease; 15% of the basal area was clean. In contrast, an adjacent essentially unmanaged stand had well over 60% of the basal area in Nectria-damaged trees - those with sunken bark because of cambial mortality. A young unmanaged stand had a little over 60% of the basal area in mostly rough-barked trees. Records indicated that the amount of beech was not reduced by the disease in any of the inventoried stands. Apparently, single-tree selection over a 50-year period has substantially improved the disease resistance and merchantable potential of the stand..