Relation between genetic diversity and pollution impact in a 1912 experiment with East European Pinus sylvestris provenances

Results are presented of genetic variation and growth decline due to pollution for 11 European populations, 1 Turkish population, and 1 Siberian population of Scots pine (Pinus sylvestris L.) growing in a provenance experiment established in 1912 in Pulawy, southeastern Poland. Since 1966 this area has been subjected to acute pollution from a nitrogen-fertilizer factory emitting high levels of SO2, NOx, NH3, and other toxic compounds. A significant negative correlation was found between genotype polymorphism indices and radial growth decline since 1966 assessed using tree-ring analysis (r = -0.58, P = 0.04). Populations with the highest values for genotype polymorphism index, numbers of alleles per locus, and numbers of genotypes per locus exhibited less of a decline in radial growth than those populations with lower values for these parameters. The results provide experimental support for the hypothesis that genetically richer populations are better adapted to changing conditions and suggest that such populations are less sensitive to air pollution in terms of growth reduction