Ecological risk assessment on the system scale: A review of state-of-the-art models and future perspectives

This paper reviews state-of-the-art models developed for ecological risk assessment and presents a system-oriented perspective for holistic risk evaluation and management. Ecological risk assessment (ERA), which is aimed at appraising a wide range of undesirable impacts on ecosystems exposed to a possible eco-environmental hazard, has been highly recommended for environmental decision-making. The existing system-based eco-risk models at different levels of hierarchical organization are reviewed, including food web-based models, ecosystem-based models and socio-ecological models are reviewed. Based on this inspection, an integrated framework characterizing problem formulation, risk characterization and risk assessment is depicted to illumine future ecological risk assessments. The possibility of integrating the various ERA modeling systems is addressed through examining the interconnections between models shown within the context of our diagrams. Furthermore, some refinements of the current system-level techniques are proposed to meet the requirements of risk evaluation in a holistic and regulatory context. We conclude that assessing ecological risk by using system-based models at different levels of organization in a combined way is an evolutionary step for the application of risk evaluation in environmental management.