Landscape genomics of the streamside salamander: Implications for species management in the face of environmental change.

Understanding spatial patterns of genetic differentiation and local adaptation is critical in a period of rapid environmental change. Climate change and anthropogenic development have led to population declines and shifting geographic distributions in numerous species. The streamside salamander, , is an endemic amphibian with a small geographic range that predominantly inhabits small, ephemeral streams. As .  is listed as near-threatened by the IUCN, we describe range-wide patterns of genetic differentiation and adaptation to assess the species' potential to respond to environmental change. We use outlier scans and genetic-environment association analyses to identify genomic variation putatively underlying local adaptation across the species' geographic range. We find evidence for adaptation with a polygenic architecture and a set of candidate SNPs that identify genes putatively contributing to local adaptation. Our results build on earlier work that suggests that some populations are locally adapted despite evidence for asymmetric gene flow between the range core and periphery. Taken together, the body of work describing the evolutionary genetics of range limits in suggests that the species may be unlikely to respond naturally to environmental challenges through a range shift or adaptation. We suggest that management efforts such as assisted migration may be necessary in future.