Variation in functional connectivity between metapopulations in urbanized and forested areas in an endangered salamander

In the face of rapid urbanization, species confront various challenges, and the consequences of limited gene flow become evident. One such illustration is the Endangered salamander Hynobius yangi inhabiting a restricted region in South Korea under a mounting urbanization pressure. The species’ metapopulation dynamics is consequently characterized by lack of sufficient gene flow. We compared the landscape genetic results between the two H. yangi metapopulations, one divided by an urbanized area or the other included within a forested area, using previously developed 14 species-specific genetic markers. We hypothesized that the population in the urbanized area will show signs of impact by the urbanization, while the population in the forested area will not. We analyzed the genetic diversity, population genetic structure, contemporary gene flow rate, and estimated the resistance values of land cover classes to assess landscape connectivity of each metapopulation. The urbanized area showed subdivided population structure, with higher inbreeding level, which was clearly distinguished from that of the forested area. The gene flow rates were consistently lower in the urbanized area. The estimated resistance values were generally higher, and the highest connectivity was confined to the peripheries in the urbanized area, in contrast to the forested area. We found the population in the urbanized area has been clearly impacted by urbanization with two times higher resistance than the forest counterpart. We recommend to establish management plans based on our result. This study will be a valuable addition to urban landscape genetic studies, especially for underrepresented taxon and region.