LAUSR

Social-ecological systems (SES) are nested, multilevel systems in which ecological and social elements interoperate through regular bidirectional interactions and feedback loops (Gunderson and Holling 2002; Holling 2001; Folke 2006). They are characterised by complex and dynamic interdependencies, between social and ecological sub-systems (Liu et al. 2015), which remain poorly understood. However, understanding the dynamics of complex SES interactions is essential for supporting both human well-being and the sustainable management of resources (Gain et al. 2019a). Failure to recognise such complex interdependencies and dynamics has led to severe environmental problems (Gain et al. 2019b) and developmental challenges, such as climate change impacts, biodiversity loss, resource scarcity, and resource degradation. The interconnectedness of complex problems cannot be assessed with traditional disciplinary approaches alone. Instead, interand trans-disciplinary approaches are required to deal with such sustainability challenges. Within the last decade, significant progress has been made with respect to analysing SES. Specifically, SES have recently emerged as a prominent analytical framing to investigate pressing sustainability issues in the Anthropocene (de Vos et al. 2019; Rockström et al. 2009). A number of frameworks have been developed to study SES, including the socialecological system framework (SESF) (Ostrom 2007, 2009; McGinnis and Ostrom 2014), the vulnerability framework (Turner et al. 2003) and the driver-pressure-state-impactresponse (DPSIR) framework (Gari et al. 2015; EC 1999; Lewison et al. 2016). To foster a better understanding of the dynamics and complexity of social-ecological interactions, a variety of assessment methods including both quantitative and qualitative approaches (e.g., system dynamics modelling, network analysis, agent-based modelling, multi-criteria analysis/ indicator-based aggregation, and integrated assessment/ decision support systems/coupled model frameworks) are now available (An 2012; Filatova et al. 2013; Lippe et al. 2019; Belton and Stewart 2002). Despite this progress, the operationalization of the conceptual frameworks through applying innovative methods and tools to allow for the sustainable development of SES is still an active field of investigation. The goal of this Topical Collection is to analyse the sustainability of SES at different scales by using recently available innovative methods, tools and approaches. The Topical Collection emerges from a 2-day workshop in Kiel, Germany (26–27 September 2018), involving key interdisciplinary researchers in the field of SES. This Topical Collection comprises papers spanning areas from theories to quantitative methods that contribute to analysing multiple sustainability challenges of complex SES at different regional contexts.