Geographic variation, nursery effects, and early selection in lodgepole pine

Journal Article

Transfer Guideline: Recommendation

Thirty provenances of lodgepole pine (Pinus contorta Dougl.) test shock raised at two nurseries, Cowichan Lake (coastal British Columbia) and RE Rock (interior British Columbia), were assessed in two 15-year field trials. Analyses indicated three broad geographic regions of genetic differentiation in British Columbia: coast, coast-interior transition, and central and southern interior. Provenance elevation was found to have a strong influence on growth. The results suggest that the present seed transfer guidelines for lodgepole pine in the interior region of this province are conservative enough to prevent the use of maladapted seed sources. Nursery effect declined over a period of 15 years, while provenance differences increased with the age of the trials. Interactions between proveances and sites also increased after age 9. This suggests that the effect due to seedling culture and environment in the nursery is short-term relative to the influence of the genetic component. Nursery grwoth was generally not a good predictor of provenance field performance.