Data from: Rangewide landscape genetics of an endemic Pacific northwestern salamander

A species' genetic structure often varies in response to ecological
and landscape processes that differ throughout the species'
geographic range, yet landscape genetics studies are rarely spatially
replicated. The Cope's giant salamander (Dicamptodon copei) is a
neotenic, dispersal-limited amphibian with a restricted geographic range
in the Pacific northwestern USA. We investigated which landscape factors
affect D. copei gene flow in three regions spanning the species'
range, which vary in climate, landcover and degree of anthropogenic
disturbance. Least cost paths and Circuitscape resistance analyses
revealed that gene flow patterns vary across the species' range, with
unique combinations of landscape variables affecting gene flow in
different regions. Populations in the northern coastal portions of the
range had relatively high gene flow, largely facilitated by stream and
river networks. Near the southeastern edge of the species' range,
gene flow was more restricted overall, with relatively less facilitation
by streams and more limitation by heat load index and fragmented forest
cover. These results suggested that the landscape is more difficult for
individuals to disperse through at the southeastern edge of the
species' range, with terrestrial habitat desiccation factors becoming
more limiting to gene flow. We suggest that caution be used when
attempting to extrapolate landscape genetic models and conservation
measures from one portion of a species' range to another.