Alpine regions sensu lato (i.e. including the Arctic) represent ecological limits for life, either altitudinal or latitudinal. They give birth to organisms with a high level of adaptation and ecosystems sustained by complex and fragile interactions among these organisms. As the main structuring biotic component of these ecosystems, plants provide a large panel of ecosystem services such as water regulation, erosion control, biomass production for livestock, carbon sequestration, or the availability of recreational areas. A growing body of evidence demonstrates that alpine plants are heavily impacted by global warming, seeking mostly refuges at higher elevation/latitude or in their neighborhood, and more rarely at lower elevation/latitude due to competition release. These effects superimpose with the effects of land use to make alpine plant communities increasingly sensitive to global change. Among land use effects, herbivory is a strong driver of species range shifts and is distributed in all alpine systems, worldwide. Alpine plants also influence the effects of global change. Positive interactions among plants are expected to buffer the effects of warming and overgrazing on ecosystems, having for example a positive feedback on the biomass available for herbivores and proposing biotic refuges for other plants. They may reduce the mismatch between plants and pollinators indebted to climate change. Characterizing with more precision the bidirectional interaction between plant communities and global change is a topical challenge to be held. To what extent are these interactions generalizable to all alpine regions? Are they driven by latitude, which has a strong impact on the functioning of alpine ecosystems by influencing pivotal drivers of plant community organization such as snow cover, phenology, elevation, precipitation and temperature cycles? Do flat, wide-ranging alpine ecosystems like the Andean Altiplano behave differently than ecosystems located in fragmented alpine peaks? The aim of the session is to present a worldwide panel of recent ecological studies along an extensive gradient from the sub-Arctic to the equatorial alpine regions to develop a conceptual framework on the bidirectional relationships between plant communities and global change. Speakers will compare approaches (different scales, experimental vs. observation, taxonomic vs. functional, snapshot vs. permanent plot, aboveground vs. belowground) and will identify geographical/methodological research gaps at a time when global changes have reached an unprecedented rate.