Relationships between people and trees are continually unfolding in the contexts of situated social-ecological systems, in which properties of the system emerge from localized interactions among complex fabrics of biological, social, and cultural actors. In current studies on social-ecological systems linked with trees, we commonly find two approaches: the first focuses on biological entities, examining the ecological dynamics of tree species and associated biodiversity. The second approach focuses on people, analyzing human agency along with historical and contemporary political or other forces shaping human-tree relationships. In this chapter, we explore social-ecological systems associated with the Pewen (Araucaria araucana), one of the most iconic and sacred trees from the southern Andes. We first describe some of our own research findings on Pewen for both of these approaches. We then develop a third perspective, which highlights social-ecological relations and has the potential to overcome both the ecological/social and the biological entity/human agency spheres. Our relational approach allows a closer enquiry on how actors (trees and their seeds, wildlife, and people) interact in complex and sympoietic social-ecological fabrics. This approach also allows us to identify the social-ecological memory of the system that emerges as an on-going complex of relations that are never stable, that must be enacted and performed on a daily basis within this specific context of South America. Furthermore, it stresses that people-Pewen fabrics are continuously built and rebuilt, putting an emphasis on the openness and future of social-ecological systems subjected to historical and contemporary drivers of change.