Patterns of monoterpene variation within individual trees in ponderosa pine

We surveyed variation in both the concentration and composition of monoterp enes in six tissues within individuals of ponderosa pine to determine (1) w hether variation exists between different tissues; (2) whether variation oc curs between samples from the north and south sides of the tree within a ti ssue, and (3) whether composition of one tissue is correlated with that of others. Wood, roots, and resin exuded from the trunk have similar monoterpe ne compositions within trees. Phloem and cones contain a higher proportion of alpha-pinene with less carene than resin, while needles are distinguishe d by high proportions of beta-pinene. Samples of the same tissue taken from the north and south sides of the tree differed little and were strongly co rrelated. Correlations were moderate across tissues within the groups shari ng similar monoterpene compositions (e.g., phloem vs, cones), but correlati ons between tissues in different groups were weak (e.g., phloem vs. needles ).