Chapter 11. Resilience Measures in Ecosystems and Socioeconomic Networks

Background and Significance of the topic: This chapter contributes to the documentation of novel network-based resilience concepts to socio-ecological systems. Although the resilience concept has been studied in depth in ecological systems, it surely has relevance outside this area and in recent years has been a main domain of study for socioeconomic systems. This chapter provides an overview of the application of resilience concepts in ecology, with a particular focus on the application of two methods developed using ecological network analysis. Methodology: The first method uses information-theory based network analysis to ascertain the trade-off between efficiency and redundancy in networks (in terms of the structure and flows). The second method uses an energy-flow based method to assess keystoneness and the direct and indirect relations in the networks. Application/Relevance to systems analysis: Earlier work using information-theory based network analysis has shown that ecological systems display a robust balance between efficiency and redundancy in networks (in terms of the structure and flows) thereby bestowing them with robust and resilient features. Results indicate that a dam ecosystem in southwest China falls just short of the optimum but suffers substantial loss of robustness when the phytoplankton community is perturbed. Application to a virtual water network shows the system is not near the robustness peak. Using the energy-flow based method, a South African estuary showed alteration of the keystone species depending on the seasonality; a land use change model of Beijing showed a decrease in mutualism due to urban expansion. Policy and/or practice implications: The case studies presented illustrate the application of ecological network analysis. Positive and negative relations between sectors of ecosystems or economic systems highlight the influence of various species and economies on one another, resulting in a comprehensive picture of relations, impacts and therefore management options to achieve balance between sectors. Discussion and conclusion: Overall, networks provided a useful model to illustrate system resilience measures, and other system analysis methods of direct and indirect impacts of system components on each other