A commons is a social organizational system where all interested parties participate in the collective use and care for common resources with an emphasis on open access, fair usage and long-term sustainability. While commons have received substantial scientific attention, we know little on how commons’ systems emerge and are sustained over time; in other words, the common-ing practices. The thesis investigated how forest are commoned and become the basis for building thriving communities both in rural and urban areas. It followed a case-study approach with two cases in Galicia (Spain), and one in North region of Portugal (North-western Iberian Peninsula). Methods included interviews, participant observation and a Participatory Action Research (PAR) project where people’s meaningful experiences in forests were collected and shared with the broader community to understand the role of affects in driving participation. The thesis offer understanding on why/how humans engage in caring for their places, and why is this relevant for sustainability transformations.