Very High Resolution Digital Elevation Models: Are Multi- Scale Derived Variables Ecologically Relevant? Very High Resolution Digital Elevation Models: Are Multi-scale Derived Variables Ecologically Relevant? 3 Short Running Title: Ecological Relevance of Vhr Dem-derived Variables 4

• Digital Elevation Models (DEMs) are often used in landscape ecology to retrieve elevation or first derivative terrain attributes such as slope or aspect in the context of species distribution modelling. However, DEMderived variables are scale-dependent and, given the increasing availability of very high resolution (VHR) DEMs, their ecological relevance must be assessed for different spatial resolutions. • In a study area located in the Swiss Western Alps, we computed VHR DEMs-derived variables related to morphometry, hydrology and solar radiation. Based on an original spatial resolution of 0.5 meters, we generated DEM-derived variables at 1m, 2m and 4m spatial resolutions, applying a Gaussian Pyramid. Their associations with local climatic factors, measured by sensors (direct and ambient air temperature, air humidity and soil moisture) as well as ecological indicators derived from species composition, were assessed with multivariate Generalized Linear Models (GLM) and Mixed Models (GLMM). • Specific VHR DEM-derived variables showed significant associations with climatic factors. In addition to slope, aspect and curvature, the underused wetness and ruggedness indices modeled measured ambient humidity and soil moisture, respectively. Remarkably, spatial resolution of VHR DEMderived variables had a significant influence on models’ strength, with coefficients of determination decreasing with coarser resolutions or showing a local optimum with a 2m resolution, depending on the variable considered. • These results support the relevance of using multi-scale DEM variables to Methods in Ecology and Evolution