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In Maine, northern hardwood stands long affected by beech bark disease often contain large numbers of American beech trees severely damaged by the disease. Methods are needed to improve stand quality by reducing the proportion of susceptible trees, and increasing the number of resistant trees. A 6-year study was conducted in north-central Maine to determine the effects of commonly used harvesting systems on the incidence and growth of beech root sprouts and seedlings. Stands were clearcut or thinned in 1991 in winter or summer. Seedlings and root sprouts in 15-ft-radius plots (174) around trees or stumps of resistant or susceptible trees were counted annually from 1992 to 1994, and the annual growth of more than 3,100 sprouts or seedlings in these plots was monitored. Initially, the most sprouts developed in the summer clearcuts, but differences attributable to harvest treatment disappeared after 4 years. By 1994, there were significantly more sprouts around resistant trees than around severely diseased trees. Interactions occurred between the amount of root disturbance (leading to root sprouts) and the amount of light available for growth. Thus, more sprouts developed after clearcuts than after thinnings, and sprout growth was best around resistant trees left standing and poorest around susceptible trees that were cut. Summer clearcuts drastically reduced the number of existing beech seedlings and prevented new “recruits.” Seedling growth was related primarily to the amount of light received as a consequence of the harvests or disease-caused crown thinning. Because of the high initial proportions of beech in these stands, it is likely that only the clearcuts will materially affect stand composition. The regeneration changes observed support other studies that reported that clearcuts (and group-selection cuts) encourage shade-intolerant and intermediate species. However, the presence of advance regeneration or significant sprout reproduction of tolerant species will ensure that those species regain their former importance. Manuscript received for publication 20 February 2001

Effect of harvesting regime on beech root sprouts and seedlings in a north-central Maine forest long affected by beech bark disease