Savolainen O, Bokma F, Garcia-Gil R, Komulainen P, Repo T
Genetic variation in cessation of growth and frost hardiness and consequences for adaptation of Pinus sylvestris to climatic changes
Forest Ecology and Management: 2004 197:79-89
Responses to climate change will include changes in species composition, but adaptation through genetic change may also be possible. The response to selection depends on the availability of additive genetic variation and the strength of selection. We found that Finnish populations of Scots pine have much genetic variation within the populations with respect to two traits related to climatic adaptation. Heritabilities (standard deviations) were 0.67 (0.16) and 0.33 (0.17) for the timing of bud set of 1-year-old seedlings and for frost hardiness 0.36 (0.14) and 0.20 (0.13) (not significantly different from zero) in the northern and southern populations, respectively. The additive genetic correlation between the traits was 0.57 (0.07). The proportion of additive genetic variation between the populations (Q(ST)) was 0.86 (0.11). Assuming that the new phenotypic optimum can be deduced based on the current match of temperature sums and phenotypic means, we test whether Scots pine in northern Finland can change to the new predicted optimum through migration and local selection during the next 100 years. The simulation model was based on monitoring 10 populations of 100 individuals. Five independent loci with two alleles were used to model the phenotypic trait of growth period. The results showed that genetic change will be slow and lag behind the moving optimum. Part of the slowness was due to the survival of current trees, which makes establishment of new trees with more suitable genotypes slower. Adaptation in species with fragmented populations and little migration could be even slower. Artificial regeneration with suitable seed sources can increase the proportion of adapted genotypes in cultivated species. (C) 2004 Published by Elsevier B.V.
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