Quantitative Analysis of Terrain Ruggedness in Reindeer Winter Grounds

We report a distinct terrain structure in high-use portions of reindeer (Rangifer tarandus tarandus) winter grounds for two regions within Norway. A new index of terrain ruggedness based on topographic maps was used for analyzing terrain structure within historic high- and low-use portions of wintering areas. Terrain ruggedness was found to be significantly higher in high-use areas. Indices of terrain ruggedness reflecting fine-scale features (10-20 m) corresponded well with the availability of potential feeding sites (<40 cm snow depth), while contour densities alone did not. Terrain structure should be considered an important habitat attribute for management planning on reindeer winter habitats. The index provides a simple method for quantifying differences in fine-scale ruggedness between habitats.