Genetic diversity and geographic differentiation in quantitative traits, and seed transfer guidelines for whitebark pine

Conference Paper

Transfer Guideline: Recommendation

Whitebark pine (Pinus albicaulis Englem.) has declined dramatically throughout its range due to white pine blister rust (caused by the fungus Cronartium ribicola J.C. Fisch.), successional replacement resulting from fire suppression, and attack by mountain pine beetle (Hopkins). Restoration is needed to halt or reverse this decline; however, no information regarding genetic diversity and local adaptation of quantitative traits is available to guide these efforts. A seedling common garden experiment was employed to assess genetic diversity and geographic differentiation of quantitative traits (QST) of whitebark pine and to determine the climatic variables driving local adaptation. Seedlings from 48 provenances from a near range-wide seed collection were grown in raised beds in Vancouver, B.C. for two years in two soil temperature treatments (ambient and cold). Seedlings were measured for second year height increment, total biomass, root:shoot ratio, date of needle flush, fall and spring cold injury, and survival. Significant differences were found between soil temperature treatments for height growth and survival, with seedlings in the cold treatment performing better. The environment where the test was grown (Vancouver, B.C.) is considerably warmer than the natural habitat of whitebark pine. While most temperate forest trees would likely benefit from the warmer soil temperatures, it appears that this is a stressor for a species adapted to cold, harsh environments.