Abstract
Smallholder farming systems in the Global South largely rely on crop diversity for their livelihood. Access to crop seeds is based on complex social networks involving a range of stakeholders – primarily farmers themselves, but also seed sellers on local markets, rural development organizations, or private actors. Social network analysis (SNA) provides a conceptual framework and tools that have been adapted to analyze the complexity of these seed circulation networks. In conjunction with qualitative approaches, the use of SNA has made a major contribution to our understanding of the social processes that shape the circulation of seeds. This chapter aims to provide an overview of research applying SNA to analyze the processes shaping seed circulation networks and how their characteristics impact crop diversity patterns and dynamics. It presents the different approaches and current challenges for not only collecting and analyzing seed circulation data but also for measuring crop diversity and improving our understanding of human decisions and actions.