Socio-material governance tensions in nature-based solution experiments: lessons from Turin

Urban experiments are widely acknowledged as key vehicles for testing and implementing greener alternatives in real-life urban settings. Less studied, however, are the everyday governance practices through which actors involved in experiments attempt to co-materialize change. Mobilizing the concept of socio-material governance tensions, this paper sheds light on how actors engage with barriers but also with opportunities stemming from the social and material realities in which experiments navigate. Through the empirical analysis of Urban Living Laboratories (ULLs) fostering Nature-based Solutions in Turin (Italy), tensions are analysed starting from the strategic choice of intervention sites, moving to the incremental practices of embedding experiments within the social and spatial fabric of the city, then addressing the challenge of leaving a socio-material legacy that goes beyond short-term initiatives. Learning from the empirical analysis, this paper highlights key governance tactics used to navigate tensions; these can inform greening experiments across many contexts. Tactics relate to proactive leadership and conflict management, intermediation, collaboration and facilitation of maintenance practices, improvisational governance, and engagement in the politics of experimentation.