The impacts of both climate change and socioeconomic processes are driving the degradation of mountains and the ecological services they provide worldwide. In the tropical Andes, compounding glacier retreat, altered hydrological and precipitation regimes (eg off-season alternation of extreme dry and wet periods), and expansion of mining and other land uses are modifying hydrological services. Although initiatives to restore ecosystems and their services are increasing, conceptual models emerging from experiences on the ground are scarce. Based upon the experience of Peru's National Institute for Research on Glaciers and Mountain Ecosystems (INAIGEM) in the Piuray Ccorimarca microbasin (Cusco) in combining participatory action research and experiments at the plot scale, this article elaborates a conceptual model for the rehabilitation of hydrological services on the social–ecological sy...