Natural regeneration of Norway spruce [Picea abies (L.) Karst.] within and around plantations in central New York.

摘要

Twenty Norway spruce [Picea abies (L.) Karst.] plantations in central New York were studied to better understand the factors affecting natural regeneration inside and outside plantations. Regeneration was compared to the following independent variables: percent canopy cover, percent understory cover, stand basal area, Norway spruce basal area, relative stand density, plantation area, species composition, soil drainage, depth to mineral soil, bordering stand community type, forest floor composition class, and harvest intensity. Within plantations, regeneration was associated with canopy cover (negative relationship) and understory cover (curvilinear relationship, maximum regeneration 30--39%). Outside plantations, regeneration was associated with 20--29% understory cover. Much of the observed variability in regeneration was not explained by the variables measured. Regeneration density declined geometrically from 27.4 m within plantations to 64.0 m outside plantations. Regeneration outside plantations was taller and older than within plantations. Combined regeneration data demonstrated higher regeneration in sites harvested three or more times since plantation maturation.