Geographic variation in the leaf essential oil of Juniperus turbinata from throughout its range in the Mediterranean

The volatile leaf oils from sixteen populations of Juniperus turbinata (= J. phoenicea subsp. turbinata) were analyzed. The variation in the major components, α-pinene (17.7 - 67.9%) and β- phellandrene (0.5 - 31.5%), was extremely large. Overall, the oils are quite variable as one might expect from the great variation in habitats ranging from coastal (8 - 15 m) to high mountains (Algeria, 1451 m, Morocco, 940 m) and from desert (Sinai) to Mediterranen. Considerable geographical variation was found in the oils dividing the populations into five groups: Portugal - Spain; Mediterranean Basin - Madeira; Canary Islands; High Atlas mountains and Sinai. There appears to be more of a mosiac than continuous geographical pattern among the populations. The utilization of oil from 12 year old herbarium specimens was examined by comparing with fresh leaves from Crotone, Italy. It appears likely that both oxidation and free radical reactions have occurred in the 12 year old herbarium leaves. In this study, it was not possible to utilize oils from herbarium specimens