ALBERT

Description: The leaf terpene composition of 645 individual lodgepole pine trees and 79 bulked samples from 111 different sites or provenances and from one putative and three western jack pine populations (10 trees each) were analyzed by gas chromatography. Numerical analysis by a centroid cluster analysis of the mean squared Euclidean distances was carried out, and percentile distributions of the individual terpenes were plotted. The data obtained confirmed the previous subdivision into the major terpene pattern types A, B, and C (or H) and five subgroups (based on the high modes in bimodal distributions); four additional subgroups were added. Except for typical coastal populations, inter- and intra-populational terpene pattern variation was high. Centroid clustering and assignment of terpene types and subgroups lead to some distinct geographical groupings. Coastal populations (ssp. contorta) were found to be rather unifornm and only a minor difference appears to exist between northern and southern populations. Those near Haines, Alaska, the Skeena Valley, southeastern Vancouver Island, and the Puget Sound showed intermediacy with interior (ssp. latifolia) stands. The Fort Bragg (ssp. bolanderi) and Samoa populations from northern coastal California contained many trees with unique terpene patterns. The interior populations (ssp. latifolia) were highly variable and inverse frequencies of the type A (high near the coast) and type B (high in and near the Rocky Mountains) were recorded in several west-east transects. Introgression with jack pine, as measured by the frequency of type C/H patterns, was extensive in northeastern Alberta and the Peace River area of British Columbia. However, some difficulty in describing recent introgression was encountered. A unique (possibly archaic) population was encountered at Petitot River. The ssp. murrayana from the southern Cascades of Oregon and northern California could not be distinguished from ssp. latifolia further north by the terpenoid data.

Description: The leaf oil terpene composition of mountain hemlock (sugamertensiana (Bong) Carr.) from eight central–coastal, three interior, and three southern populations was determined. High intra- but low inter-population variation was found. No significant elevational differences were recorded. Most trees from the southern populations had lower car-3-ene and higher α-pinene and β-phellandrene percentages than those from northern locations. Interior populations did not differ extensively from coastal populations. Owing to the high tree-to-tree variability, putative hybridization of mountain hemlock with western hemlock would be difficult to detect by leaf oil terpene analysis.

Description: The leaf oil terpene composition of lodgepole pine stands from contrasting moisture regimes (400–1200 mm precipitation) within upland and bog sites in the Prince George area of central British Columbia was investigated. In addition to the terpene patterns recorded previously, a new one with relatively high percentages (5–28%) of the terpinene group was found. This pattern was encountered mainly in old trees with very low yields (less than 0.1%) of volatile oil, especially in trees from shaded stands. The absence of resin canals in the leaves of such trees may be the reason for the low yields, but the reason for the link with relatively high terpinene group percentages is obscure. Young trees growing in the vicinity of such stands had mainly the normal patterns. No differences between upland and bog sites or dry and wet sites were found in young trees. Hence, old trees from bogs or wet sites east of Prince George provided progeny with the normal terpene patterns, even though many of the old trees have the new terpene pattern. Samples from two 12- to 13-year-old provenance trials originating from west and east of Prince George had terpene patterns similar to those of the young trees from the natural stands.