Assessing populations responses to climate in Pinus sylvestris and Larix spp. of Eurasia with climate-transfer models

Journal Article

Transfer Guideline: Recommendation

Weibull regression models were used to relate height and survival of Eurasian populations of Scots pine (Pinus sylvestris L.) at age 13 and three species of larch (L. sukaczewii Dylis, L. sibirica Ledeb., and L. gmelinii (Rupr.) Rupr.) at age 12 to the difference in climate between their provenance and a planting site. Univariate models using five climate variables as predictors all were statistically significant (p < 0.01), and all but the pine survival functions received strong verification with independent data. The models showed that the growth and survival of most populations of the pine and each species of larch are enhanced when populations are transferred from their provenance to warmer climates. The results are consistent with the view that most populations occur in climates that are suboptimal, the degree of which is directly related to the severity of the climate. Because of this, projected responses to a climate-change scenario of the Hadley Centre were highly variable geographically. Short-term plastic responses tended to be strongly negative for the least severe climates and strongly positive for the most severe. Long-term evolutionary responses primarily reflected extirpation and immigration for the species of larch but showed additionally for the pine that the accommodation of global warming will require a redistribution of genotypes throughout the species'range.