Dcopei_landscape_distances

These 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.