PS 39-85 - Does the biogeographic barrier account for the separation of seven Hynobius species in South Korea?

Abstract: There are a total of 10 species of salamanders in Korea, of which seven belong to the genus Hynobius. Hynobius leechii, Hynobius unisacculus, Hynobius notialis, Hynobius perplicatus, Hynobius quelpaertensis, Hynobius yangi, and Hynobius geojeensis. Compared to other countries, it is rare for a peninsula with a relatively small area to have as many species belonging to the same genus, and three of the seven species - geojeensis, notialis, and perplicatus - were only recently recognized as species in 2020, so not much information about them has been studied. The distribution of these seven species shows that their habitats are closer together in the south. However, among these species, the yangi is classified as the second class of endangered wildlife in Korea, so for the protection and conservation of the species, advanced research on seven species that share similar ecological status is necessary. Therefore, the purpose of this study is to investigate whether the presence of environmental barriers between seven clades of salamanders of the genus Hynobius affects species divergence through modeling. There are two thesis questions. Do hynobius species in South Korea have separate niches? If so, are they separated by ecologically significant barriers between each species? To check whether the species have separate niches, we conducted SDM using MAXENT, R STUDIO, and ARC MAP, and to check the existence of barriers between species, we finally completed environmental niche modeling and linkage mapper with ARC GIS's CIRCUITSCAPE. As a result, in the SDM conducted to identify the niche of the first species, a total of 6 climate variables and 14 environmental variables were found to have significant contributions, and for the remaining 6 species except leechii, the results of each species did not deviate significantly from the current boundaries. But still leechii do not deviate much from their current boundaries. Nicheoverlap is measured as the percentage of the overlap between pairs of species with adjacent habitat boundaries using codes in r studio, and the percentage was significantly higher in some species, confirming the existence of barriers. In conclusion, this study is expected to complete the linkage mapper between Hynobius species in Korea, identify their micro habitat and past evolutionary processes, and fill gaps in research on these species.