Unique and Under Pressure: Conservation Genetics of an Isolated Alpine Salamander Population

The Alpine salamander (Salamandra atra) is a cold-adapted amphibian with low dispersal capacity, endemic to the Alps and Dinarides. Isolated populations at the range's margins are especially vulnerable to habitat fragmentation and genetic erosion. We investigated the population genetic structure of S. atra in the Koralpe, a biogeographically important mountain range in southeastern Austria. Using mitochondrial DNA, we found that the Koralpe population harbors unique genetic variants not shared with other known populations. Strong genetic differentiation and low connectivity among Koralpe subpopulations, inferred from microsatellites, indicate long-term isolation, likely caused by unsuitable intervening habitats and the species' limited dispersal capacity. Although the estimated effective population size (Ne = 245) is moderate and no severe genetic bottlenecks were detected, subpopulation sizes are likely small. These findings highlight the conservation value of this peripheral population and support its recognition as a distinct management unit. In situ protection, improved landscape connectivity, and continued (genetic) monitoring are essential for the population's long-term survival. Given its unique genetic signature and pronounced structuring, targeted conservation measures are critical-especially under increasing pressure from climate change and habitat degradation. Preserving this isolated lineage will contribute to local biodiversity and help safeguard the evolutionary potential of S. atra as a whole.