Genetic variation of silver fir (Abies alba Mill.) in the Palatinate Forest

Silver fir in the southern Palatinate Forest grows naturally on dry sandy sites in one of the areas of Germany with the lowest precipitation. This region represents the northwestern edge of its natural range. In the present study, six EST-SSRs were used to genetically characterize a representative old-growth stand and its regeneration. Due to the pilot nature of the study, the results refer only to the silver fir stand examined and therefore cannot provide generally valid statements about the entire population. Compared to studies using similar methods, the stand shows an average genetic variation for Central European silver firs. The average number of alleles (Na) is 6.5 alleles locus⁻¹, while the average number of effective alleles (Ne) is 3.79 alleles locus⁻¹. Relatively high observed and expected heterozygosity values were measured. At 61.8 %, the current heterozygosity is very similar to the expected heterozygosity of 61.2 %. No significant differences in genetic variation were observed between generations. The genetic information was passed on to the next generation without the loss of allelic variants. The fact that more private alleles were found in the natural regeneration indicates a high external pollen input. There was no evidence of isolation, genetic drift, or inbreeding. No family structures were recognizable on the basis of the investigation of the fine-scale spatial genetic structure. Based on the results, the population is not currently classified as endangered, which is why in situ conservation is considered appropriate.