DOI: 10.5061/dryad.8j65p
title: Data from: Replicated landscape genetic and network analyses reveal wide variation in functional connectivity for American pikas

description: Landscape connectivity is essential for maintaining viable populations,
 particularly for species restricted to fragmented habitats or naturally
 arrayed in metapopulations and facing rapid climate change. The importance
 of assessing both structural connectivity (the physical distribution of
 favorable habitat patches) and functional connectivity (how species move
 among habitat patches) for managing such species is well understood.
 However, the degree to which functional connectivity for a species varies
 among landscapes, and the resulting implications for conservation, have
 rarely been assessed. We used a landscape genetics approach to evaluate
 resistance to gene flow and, thus, to determine how landscape and
 climate-related variables influence gene flow for American pikas (Ochotona
 princeps) in eight federally managed sites in the western United States.
 We used those empirically-derived, individual-based landscape resistance
 models in conjunction with predictive occupancy models to generate
 patch-based network models describing functional landscape connectivity.
 Metareplication across landscapes enabled identification of limiting
 factors for dispersal that would not otherwise have been apparent. Despite
 the cool microclimates characteristic of pika habitat, south-facing
 aspects consistently represented higher resistance to movement, supporting
 the previous hypothesis that exposure to relatively high temperatures may
 limit dispersal in American pikas. We found that other barriers to
 dispersal included areas with a high degree of topographic relief, such as
 cliffs and ravines, as well as streams and distances greater than one to
 four kilometers depending on the site. Using the empirically-derived
 network models of habitat patch connectivity, we identified habitat
 patches that were likely disproportionately important for maintaining
 functional connectivity, areas in which habitat appeared fragmented, and
 locations that could be targeted for management actions to improve
 functional connectivity. We concluded that climate change, besides
 influencing patch occupancy as predicted by other studies, may alter
 landscape resistance for pikas, thereby influencing functional
 connectivity through multiple pathways simultaneously. Spatial
 autocorrelation among genotypes varied across study sites and was largest
 where habitat was most dispersed, suggesting that dispersal distances
 increased with habitat fragmentation, up to a point. This study
 demonstrates how landscape features linked to climate can affect
 functional connectivity for species with naturally fragmented
 distributions, and reinforces the importance of replicating studies across
 landscapes.
description: Genetic Distance
 MatricesOne .csv file per study
 site including the genetic distances among individual pika samples.
 Genetic distances were calculated from individual genotypes as a principal
 conponents distance calculated using the ecodist package in
 R.Castillo_Genetic_Distance_Matrices.zipPika Habitat Patch CentroidsOne .csv file per study site including the xy coordinates (UTM, NAD83) for each pika habitat patch used in network analyses. Patch IDs correspond to Patch IDs in Patch Distance Matrices files. Centroids calculated in ArcGIS10.0.Castillo_Patch_Centroids.zipPika Habitat Patch DistancesOne .csv file per study site as a 3-column matrix including resistance distances and Euclidean distances among pika habitat patches. Resistance distance was calculated from the perimeter of each patch (polygon) using an overlapping tile approach with the program Circuitscape. Patch IDs correspond to Patch IDs in the Habitat Patch Centroid files. Resistance distance was not calculated between habitat patches separated by &gt;10km.Castillo_Patch_Distance_Matrices.zipPika Genetic Sample LocalitiesOne .csv file including the xy coordinates (UTM, NAD83) for each pika genetic sample used in analyses. Data was collected in the field on handheld GPS units.Castillo_Sample_Localities.csvLandscape Resistance Surface Raster FilesFinal landscape resistance surfaces for each study site.Castillo_Ressitance_Rasters.zip