Abstract: Societies have organized their relationship with nature in different ways, but have always been dependent on a material exchange with it. This social metabolism links society and nature and encompasses both socio-cultural and natural processes. An interdisciplinary approach is required to analyze these complex relationships. It therefore seems sensible to examine societal relationships with nature using a bridging concept that combines different disciplinary perspectives. In order to reduce the multitude of parameters, we have focused on a specific socio-natural site that already exhibited a close interweaving of socio-cultural and natural factors at an early stage: alluvial landscapes. These show a specific fluvio-social metabolism, which significantly shaped the “fluvial anthroposphere” and continues to have an effect today through path dependencies. The essay is divided into three parts: First, fluvio-social metabolism is located as a suitable bridging concept within the environmental sciences. Second, we discuss the possibilities and limitations of its analysis, illustrating specific resource complexes using a hypothetical example of a mill for tannery. In the third part, we discuss the concept's epistemological potential for the identification of “fluvial anthropospheres”. The bridging concept of fluvio-social metabolism combines disciplines such as archaeology, history and geography. The concept is used to investigate how human-influenced material flows and cycles changed the shape and development of floodplains and their social structures over time. It takes into account the exchange of material resources (such as raw materials and energy) and immaterial aspects (such as cultural techniques and institutions) between nature and society. Both intended interventions and unintended consequences (e.g. environmental changes) as well as the intrinsic dynamics of materials are taken into account. These material flows run along resource complexes that comprise specific combinations of materials, technologies, practices and social structures and shape the dynamics of riverine landscapes. The concept of fluvio-social metabolism can be integrated into existing models such as the human ecosystem or the socio-natural site and captures the changes in river landscapes and social structures over time as a transformative process. Keywords: fluvio-social metabolism; fluvial anthroposphere; environmental history; regional history; archaeology; geography; resource complexes; social ecology; socio-natural site; floodplain landscapes Schlagwörter: Fluvio-Sozialer Metabolismus; Fluviale Anthroposphäre; Umweltgeschichte; Landesgeschichte; Archäologie; Geografie; Ressourcenkomplexe; Sozialökologie; Sozio-naturaler Schauplatz; Auenlandschaften