Abstract for: Resource dependency as the foundation of sustainability and resilience theory

Although the related concepts of sustainability and resilience are widely cited, there is a lack of clarity about their meaning and relationship in systems terms. This article summarises the historical roots of the concepts with particular reference to the resilience literature which has its origins in the study of ecological systems, and has since been expanded to encompass socio-ecological systems. The twin concepts are explored through a review of system modelling studies, in particular predator-prey models, and a simple hierarchical system dynamics model of a four level food chain founded on abiotic flows is presented. The model produces a small number of behaviours that replicate the observed real world behaviour of ecosystems but does not produce the less plausible outcomes produced in many predator-prey models. The simulations explore system response to various types of ‘shock’ and the outcomes are used to reflect on the various definitions of sustainability and resilience. The results reinforce the notion that shocks to the abiotic system flows at the foundation of all ecosystems present the greatest threat as they affect all trophic levels. It is proposed that a sustainable system is one in a stable equilibrium that is resilient to specific disturbances.