Currently, 50% of spruce and 75% of the Scots pine plants used in reforestation in Sweden are supplied by seed orchards, a value that will continue to rise in coming decades. Seed orchards are established with genotypes intensively selected for timber production gain. To stimulate seed production, orchards for northern climates have been established 2-4 latitudinal degrees south of the target utilization areas. This unavoidably introduces pollen from trees adapted to more southerly conditions into the selected northern gene pool. The fusion of southern genes is perceived as a negative factor as it decreases both the hardiness of the orchard crops and the expected breeding gain in production. Alternatively, could this breeding practice even have a positive effect on the long term adaptability and production of the northern forests under climate change scenarios? Could it be viewed as a means to assist gene flow for more rapid response to climate change?
This project aims to conduct parallel analyses on adaptive trait and genetic variation in natural stands, breeding population and seed orchard crops of Scots pine and Norway spruce for northern climate. We will perform whole genome scan for allele frequency changes in different groups of populations and to establish genetic-environment and genetic-phenotype associations. These investigations will provide important insights into the genetic basis of climate adaptation, and the long-term consequences of assisted gene flow to boreal forests.