Cambial and internal electrical resistance of red spruce trees in eight diverse stands in the northeastern United States
Rating systems are being developed to determine the degree to which forests are at risk from pests, pathogens, and anthropogenic disturbances. Measurements of electrical resistance of living trees have been shown to be correlated with cambial growth and alterations of wood function in a wide range of species. A comparison was made of patterns of cambial electrical resistance and of stem internal electrical resistance for eight red spruce (Picearubens Sarg.) stands in the northeastern United States. Stands were compared by a new procedure using cambial electrical resistance profiles. The resulting groupings provided a refinement of vigor categories over other comparative methods, and the technique should prove useful for guiding management decisions. No direct relationship was found between the internal tree condition and the cambial electrical resistance, and implications of this with regard to monitoring forest stand health are discussed.