Ecological Archives A022-047-A1

Stephen F. Spear, Charles M. Crisafulli, and Andrew Storfer. 2012. Genetic structure among coastal tailed frog populations at Mount St. Helens is moderated by post-disturbance management. Ecological Applications 22:856–869.

Appendix A (Table A1). Variables used in least-cost (LC) path development and/or as independent variables in regression models.

Variable Units LC path Data Source(s) Resolution Calculation
along LC paths
Topographic distance m Yes Digital Elevation Model (DEM) 30 × 30 m Sum
Forest/Stream none Yes
(1000:1 cost)
National Land Cover Dataset (1)
Gifford Pinchot National Forest (2)
30 × 30 m not included
Distance through
non-forest
m No NLCD 2001 (1) 30 × 30 m Sum
Canopy Cover percent No NLCD 2001 (1) 30 × 30 m Weighted avg.
Heat Load Index (hli) none No DEM (3) 30 × 30 m Weighted avg.
Slope degrees No DEM 30 × 30 m Weighted avg.
Frost-free period (ffp) days No spline-based model (4) 1 × 1 km Weighted avg.
Growing season (Apr–Sep)
precipitation (gsp)
mm No spline-based model (4) 1 × 1 km Weighted avg.

Literature Cited

1. Homer, C., C. Huang, L. Yang, B. Wylie, and M. Coan. 2004. Development of a 2001 national landcover database for the United States. Photogrammatic Engineering and Remote Sensing 70:829–840.

2. Gifford Pinchot National Forest. 1998. Stream. USDA Forest Service, Gifford Pinchot National Forest.

3. McCune, B., and D. Keon 2002. Equations for potential annual direct incident radiation and heat load. Journal of Vegetation Science 13:603–606.

4. Rehfeldt, G. E. 2006. A Spline Model of Climate for the Western United States, General Technical Report RMRS-GTR-165. Department of Agriculture, Forest Service, Rocky Mountain Research Station. Fort Collins, CO US.


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