Spatial patterns of alpine phytomass, primary productivity, and related calorific resources

Abstract

Abstract There is an obvious need for a better understanding of the drivers of local spatial heterogeneity in alpine phytomass. Facing challenges in scaling relations with data available either at biome‐scale or at plot‐scale we wanted to disentangle the driving forces behind spatial patterns of phytomass, productivity, and energy content in alpine reindeer pastures. Our hypothesis was that we would find a set of environmental variables that explain the patterns of fodder resources, thereafter facilitating a spatial upscaling of plot‐based data to the broad‐scale range of the reindeer pastures. Based on a nested stratified random design, we used univariate and multivariate statistical analyses to relate fodder resources to environmental data along fine‐scaled micro‐topographical gradients which were embedded in broad‐scaled gradients of grazing intensities and climatic conditions throughout Norway. We found that the spatial heterogeneity of resources was not sufficiently explained by our comprehensive set of commonly available environmental variables. This reveals that micro‐spatial patterns of energetic fodder resources for reindeer in alpine landscapes are miscalculated by common approaches and that the functionalities behind these micro‐spatial patterns are not yet fully understood. Hence, our results suggest that broad‐scale models cannot account for the functionality in alpine environments, highlighting that resolution, scale, and the functional context are crucial aspects in understanding broad‐scale resource patterns of reindeer pastures.

Keywords

• arctic and alpine research
• cold regions
• landscape ecology
• linear mixed effects models
• mountains
• normalized difference vegetation index