20 autochthonous populations of Norway spruce (Picea abies (L.) Karst.) were studied which are located in mountainous and subalpine vegetation zones in Switzerland. For each of 2000 trees, multilocus genotypes were identified at 18 enzyme coding gene loci. Genetic inventories revealed large genetic variation within populations and relatively small interpopulational variation. Compared to results from inventories in lower elevated regions northward and southward of the Alps, intrapopulational variation is not smaller in high elevated populations. Generally, frequency distributions of genetic types tend to deviate substantially from evenness. The geographic variation of allele frequencies supports the hypothesis of postglacial re- immigration extra to the commonly accepted east-west routes. Results serve as criteria for gene conservation in situ. Preservation of genetic variability is required particularly under changing environmental conditions which challenge Alpine forest ecosystems.
