The French Alps long-term socio-ecological research platform (LTSER Alps) focuses on the coupled dynamics of alpine ecosystems, their uses and climate. The creation of the platform has provided a unique opportunity to initiate or strengthen collaborative transdisciplinary research involving a range of natural and social scientists (ecologists, agronomists, climatologists, sociologists) and key regional stakeholders from the production, tourism and nature conservation sectors. The main research questions were built on long-term research at two sites. They include climate change effects on biodiversity and ecosystem functioning, and coupled dynamics of grassland management, biodiversity and ecosystem functioning through ecosystem services, using not only observations of natural and human systems, but also manipulative experiments of climate, management and plant and soil diversity to feed models. The LTSER platform has fostered three important types of advances: (1) Long-term data consolidation and sharing. (2) Invigorating interdisciplinary projects that had remained for many years in the state of drafts (e.g. coupled transformations of economic functioning of farm holdings and mountain summer pastures dynamics; mutations of alpine tourism in the face of climate change). (3) New transdisciplinary projects including climate change adaptation of mountain territories , integrated carbon cycle modelling in response to historical land use change and climate; a sociological study of the process of construction of the LTSER platform.