Leaf trait variability between and within subalpine grassland species differs depending on site conditions and herbivory

Plant traits are commonly used to predict ecosystem-level processes, but the validity of such predictions is dependent on the assumption that trait variability between species is greater than trait variability within a speciesthe robustness assumption. Here, we compare leaf trait intraspecific and interspecific variability depending on: geographical differences between sites, and five years of experimental herbivore exclusion in two vegetation types of subalpine grasslands in Switzerland. Four-leaf traits were measured from eight herbaceous species common to all 18 sites. Intraspecific trait variability differed significantly depending on site and herbivory. However, the amount and structure of variability depended on the trait measured and whether considering leaf traits separately or multiple leaf traits simultaneously. Leaf phosphorus (P) concentration showed the highest intraspecific variability, while specific leaf area (SLA) showed the highest interspecific variability and displa...