Genetic variation in lodgepole pine and white spruce in Alberta: Adaptation to climate and implications for assisted migration to address climate change
This research is part of the Genome Canada “AdapTree” project, aimed at assessing the adaptive portfolio of reforestation stocks for future climates. We pursue empirical, experimental, and modeling approaches to guide assisted migration efforts for climate change in Alberta for both natural populations and improved breeding stock, synthesizing data from 1) field trials for long-term growth traits, 2) growth chamber common gardens for adaptive traits, and 3) single nucleotide polymorphisms that are either linked to adaptive traits or climatic gradients. We ask how natural populations are adapted to climate, and apply the results to modify current provincial seed transfer guidelines, which may no longer be valid given the warming trends and changes in precipitation patterns observed over the last several decades in western North America.
The analysis of growth chamber data revealed broadly defined groups of locally adapted populations that closely model Alberta’s current species-specific breeding regions. Analyses of long-term growth traits found that seed performance appears to be closely linked to temperature and precipitation. Seed originating in mild and wet Rocky Mountain Foothills ecosystems are poor performers in drier boreal ecosystems relative to local sources. Within the boreal region, lateral transfers west from drier ecosystems outperform local sources in historically wetter environments. Anticipated future decrease in precipitation will likely have a negative effect on tree performance without human intervention through assisted migration of suitably adapted genotypes. To facilitate optimal selection of seed for planting in assisted migration efforts, we provide performance estimates for individual seed collection as part of a species-specific database tool.