Co-design approaches in land use related sustainability science-A systematic review

"Co-design" has become a widely used approach in land use science to address complex sustainability challenges. However, the term "co-design" is applied in quite different contexts, often implying different meanings and practices to implementation which leads to terminological fuzziness. Since an overview and synthesis of these different approaches is still missing, this systematic review aims at shedding light on the different meanings of "co-design," systematizing the body of literature on land use sciences, and exploring how scientists and experts implement co-design processes in practice. Applying a quantitative meta-analysis of 88 SCOPUS-listed publi-cations, we identified two main objectives and types for conducting co-design research: Seventy-six studies aim at jointly developing problem-solving interventions for sustainable transformations ("intervention type"), whereas 12 studies seek to collaboratively develop research questions or agendas (type: "co-created research designs"). Using a qualitative in-depth analysis, we further divide the "intervention type" corpus into four subtypes: (a) "researcher-led and model-based" and (b) "social science-driven intervention" studies applying a rigorous pre-defined study design where scientists are the dominant actors. Subtype (c) includes studies that develop "design-led and practice-oriented interventions" and rather focus on practical outcomes than on sci-entific knowledge production. The subtype (d) "transformative transdisciplinary interventions and living labs" shows the strongest ties to transdisciplinary research philosophy, theory, methodology, and practice. Co-citation -network analyses reveal that these subtypes have partly evolved independently from each other by using different theoretical and methodological references. Generally, "co-design" is applied in various ways, but without an agreement on what exactly "co-design" entails. It is often used intuitively across the subtypes, without carefully reflecting the existing theoretical and methodological foundations. Finally, we provide suggestions for supporting an integration of "co-design" into future research projects in a more conscious and sound way.