Microsatellite data for Cryptopygus antarcticus travei

Biodiversity patterns are shaped by the interplay between geodiversity and organis-mal characteristics. Superimposing genetic structure onto landscape heterogeneity(i.e., landscape genetics) can help to disentangle their interactions and better under-stand population dynamics. Previous studies on the sub-Antarctic Prince EdwardIslands (located midway between Antarctica and Africa) have highlighted the im-portance of landscape and climatic barriers in shaping spatial genetic patterns andhave drawn attention to the value of these islands as natural laboratories for study-ing fundamental concepts in biology. Here, we assessed the fine-scale spatial geneticstructure of the springtail, Cryptopygus antarcticus travei, which is endemic to MarionIsland, in tandem with high-resolution geological data. Using a species-specific suiteof microsatellite markers, a fine-scale sampling design incorporating landscape com-plexity and generalised linear models (GLMs), we examined genetic patterns overlaidonto high-resolution digital surface models and surface geology data across two 1-kmsampling transects. The GLMs revealed that genetic patterns across the landscapeclosely track landscape resistance data in concert with landscape discontinuities andbarriers to gene flow identified at a scale of a few metres. These results show thatthe island's geodiversity plays an important role in shaping biodiversity patterns andintraspecific genetic diversity. This study illustrates that fine-scale genetic patternsin soil arthropods are markedly more structured than anticipated, given that previ-ous studies have reported high levels of genetic diversity and evidence of geneticstructing linked to landscape changes for springtail species and considering the ho-mogeneity of the vegetation complexes characteristic of the island at the scale oftens to hundreds of metres. By incorporating fine-scale and high-resolution landscapefeatures into our study, we were able to explain much of the observed spatial geneticpatterns. Our study highlights geodiversity as a driver of spatial complexity. Morewidely, it holds important implications for the conservation and management of thesub-Antarctic islands.