A rangewide comparison of outlying and central lodgepole pine populations based on oleoresin monoterpene analysis

Monoterpene composition of the shoot cortical oleoresin from a number of centrally-located natural stands of Lodgepole pine was compared with that from populations derived from a variety of more peripheral parts of the natural range. The chemical diversity in interior populations was high; over much of the periphery it was much lower but locally in extreme north and north-eastern areas it became very high, a feature associated with possible glacial refugia and with recent introgressive influences from Jack pine. There is evidence for a more generally pervasive and probably more ancient interaction between, or progenitor of, the two species over a large part of the range, particularly in south-central British Columbia. The chemotypic distributional data are discusssd in relation to the recent history of the species.