Dealing with uncertainty in ecosystem model scenarios: Application of the single-model ensemble approach

Complex ecosystem models are often used as a tool for resource managers in the application of ecosystem based management. The uncertainty associated with these models is a major stumbling block in their acceptance as a management tool. Yet, conducting a rigorous uncertainty analysis of complex models is often not feasible. We present an alternative approach to assessing the impact of parameter uncertainty on the outcome of management scenarios on a lake ecosystem. We applied the single-model ensemble approach to the ecosystem model DYRESM-CAEDYM and Lake Kinneret, Israel. We introduced uncertainty to parameters and conducted an ensemble of simulations for three scenarios. Despite the large degree of uncertainty in parameter values the trends in ecosystem response were consistent with those observed based on calibrated parameter values. The variation in results allowed us to estimate the consequences of parameter uncertainty on lake resource management without the need for a comprehensive uncertainty analysis.