Summary
The timing of periodic life-cycle events in plants is an important factor determining how species and populations will react to climate change. Station scientists evaluated annual patterns of basal-area and height growth of coast Douglas-fir seedlings from four seed sources that were planted in four diverse environments as part of the Douglas-fir Seed-Source Movement Trial. Variations in the height- and basal-area growth metrics were correlated with different aspects of the seed-source environments: precipitation, for height growth, and minimum temperature, for basal-area growth. Our results indicate that multiple aspects of growth phenology should be considered along with other traits when evaluating adaptation of populations to future climates. Genetic variation in growth phenology is a potentially important resource for mitigating some of the effects of climate change. Phenological traits can be considered with other factors in determining whether a genotype is well adapted to a particular environment. Distinction should be made between different aspects of growth phenology. Variation in diameter-growth phenology appears to be an adaptation to a different set of environmental factors than budburst or height-growth phenology.
