How plants will respond to climate change is among the most pressing questions in ecology and evolution. To answer this question evolutionary ecologists usually focus on morphological traits and fitness, ecophysiologists focus on physiological processes, while geneticists focus on genes. Moreover, they usually work on different model systems, which does not promote the achievement of a complete picture. Here we will bring together the disparate fields of ecophysiology, evolutionary ecology and genetics to study phenotypic plasticity and micro-evolution of the long-lived alpine plant Salix herbacea in order to understand potential responses to climate change. In a common field survey along three altitudinal transects, we will collaboratively assess how variation in phenological, ecophysiological, morphological and fitness-related traits, as well as in molecular markers and candidate genes is associated with altitude and micro-habitats (ridges and snow beds). Evolutionary responses in different micro-habitats will be predicted using quantitative genetic parameters. This study will generate hypotheses on adaptive traits and ecologically relevant genetic variation that will be tested in a common reciprocal transplant experiment. In this experiment, we will transplant replicated clonal fragments of S. herbacea between low and high altitude sites and between micro-habitats within these sites, and measure the same set of traits as in the common survey. We will also test for phenotypic plasticity in and selection on these traits. To get an even more comprehensive picture of potential direct and indirect consequences of climate change on S. herbacea, we will in additional experiments test the importance of competitive and facilitative effects of neighboring species on growth of S. herbacea, the importance of soil micro-organisms for germination and seedling establishment, and study whether molecular marker and candidate gene alleles are associated with germination and early establishment. This will be the first comprehensive project on determinants of the current distribution of a dominant, long-lived, clonal, alpine shrub, and potential plastic and evolutionary responses of the study species to ongoing and future climate change. By collaborative collection and sharing of data, we will be able to address questions that could not be addressed by each researcher separately.