GEOGRAPHIC VARIABILITY OF PINUS-FLEXILIS XYLEM MONOTERPENES

Wood from 237 trees of Limber pine (Pinus flexilis) was collected in 24 localities throughout the species range and analysed by gas chromatography for monoterpenes and volatile alkanes: alpha-pinene, beta-pinene, 3-carene and limonene were the main constituents. Fourteen other monoterpenes plus n-undecane were also found. The southwestern populations from California and adjoining areas of Nevada separated from the rest on the basis of increased amounts of alpha-pinene and smaller amounts of myrcene, 3-carene, limonene and beta-phellandrene. This differentiation was rationalized by the separation of the two population groups by deserts during the Quaternary.