DOI: 10.5061/dryad.s4sh6
title: Data from: Rangewide landscape genetics of an endemic Pacific northwestern salamander

description: 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.
description: Dicamptodon copei
 microsatellite genotype dataDicamptodon copei tissue
 samples were collected from the field in 2006-2008. DNA was extracted
 using DNeasy tissue kits (Qiagen) according to the manufacturer’s
 protocols. Eleven microsatellite loci were amplified using PCR with
 fluorescently labeled primers, using PCR conditions from Steele et al.
 (2008) (Table S1, Supporting Information). Microsatellite products were
 run on an ABI 3730XL automated sequencer (Applied Biosystems) at the
 Washington State University LBB1 core facility and genotyped using ABI
 GENEMAPPER 3.7 software. The data include microsatellite fragment lengths
 for each study site (rows) and (diploid) locus
 (columns).Dcopei_microsatdata_10242012.csvDcopei_landscape_distancesThese data are landscape distances between study sites calculated using least cost path (LCP) analysis (columns B-JJ) and Circuitscape resistance analysis (columns JL-KB). LCP data represent the weighted averages of all landscape layers along a particular LCP (indicated in the row below the region name), and all LCPs were corrected for topography. Landscape cost surfaces were developed using the following GIS datasets downloaded from online databases (including abbreviations and source of data citations from Trumbo et al. 2012): stream networks (USGS 2001) (str10 = 10:1 cost of movement outside streams, str100 = 100:1 cost of movement outside streams), canopy cover (cc) (Homer et al. 2004), frost-free periods (ffp) (Rehfeldt 2006), growing season precipitation (gsp) (Rehfeldt 2006), landcover (lc) (Homer et al. 2004), and heat load index (hli) (McCune and Keon 2002). For streams, a "no" following abbreviation means that large rivers were excluded from the stream network. For all continuous variables, a "1" following the abbreviation means an exponentially increasing non-linear response, such that the transformed surface T1 = 100^ (original cost surface). A "2" following the abbreviation means an exponentially decreasing non-linear response such that the transformed surface T2 = 100 - 100^(1- original cost surface). The "strghtline" data are null models of isolation by Euclidean distance alone.