Cambial electrical resistance does not assess vitality of individual sweetgum trees
Journal of Arboriculture
International Society of Arboriculture
Cambial electrical resistance (CER) was assessed over a year-long period, using the Shigometer, for 109 sweetgum trees (Liquidambarstyraciflua) planted along streets in Seattle, Washington. CER decreased through the spring, reached a minimum in summer, increased through the fall and was maximal in mid-winter. The seasonal maximum was 200-600% greater than the summer minimum. CER measurements could not be related to growth parameters such as seasonal shoot increment and diameter growth.
Clark, J. R., R. Kjelgren, J. Hushagen, and J. Fiore. 1992. Cambial electrical resistance does not assess vitality of individual sweetgum trees. J. Arboricult. 18:1-5.