In this research report we develop the cross-disciplinary theory and practice of NbSas co-evolutionary technology. Following established terminological conventions, weuse the term ‘cross-disciplinary’ as referring to collaboration among and conceptualand methodological integration across several established scientific disciplines, in ourcase mainly• the sciences (biology, ecology),• the social sciences (mainly sociology and economics) and• the humanities (mainly anthropology, semiotics, and philosophy). This report is divided into three main chapters. In chapter 2 we develop basic conceptsof understanding NbS as more-than-human co-evolutionary technology in the contextof Earth system sciences and introduce various meanings of co-evolution in relationto concepts such as co-creation. We further specify these meanings in suggesting athreefold conceptual framework of niche, infrastructure and landscape, in which weapproach the co-evolutionary technology of NbS as multi-species niche construction.Chapter 3 elaborates on the theoretical foundations of these three key concepts tobuild the ground for perspectives on NbS practice which is the topic of chapter 4. Inthis chapter, we approach NbS multi-species niche construction as more-than-humaninfrastructural landscaping and introduce key aspects of this peculiar human activity.