Geographic Variation in Leaf and Twig Monoterpenes of Balsam Fir

Gas chromatography of leaf and twig extracts from a provenance test revealed seven principal monoterpenes. Tissues differed in relative quantity for six monoterpenes; provenances differed for six monoterpenes from leaves, and all monoterpenes from twigs. All of the six compounds except 3-carene were present in all samples. Cluster analysis subdivided the species range into eastern and western clusters bordering at about 80 °W Long. Within-cluster variation was greater in the eastern grouping. Four monoterpenes from leaves and all monoterpenes from twigs followed the east–west pattern. The illustrated pattern of geographic variation complemented results of other studies.