60 Network Structure Changes in Food Webs: Implications to Ecological Risk Assessment (PSAM-0062)

The objective of this paper is to provide a new Ecological Risk Assessment (ERA) method that simulates the structure and dynamics of complex ecological networks in a holistic manner and is appropriate for long-term temporal scales. In this study, the introduction of invasive or non-indigenous species (NIS) into an ecological system (food web) is chosen as an environmental Stressor based on continued scientific interest regarding biological invasion. Here, we propose a novel in silico complement to ERAs that estimates the invasive ability of NIS and predicts which habitats and keystone species in the habitats are at risk. Major outputs from simulations include not only population dynamics, but also species and web structure properties. The simulations show that the properties of the invader are more important determinants of invasion success than the properties of the food web being invaded. This result suggests that management strategies that target invaders may be more successful than those that focus on the characteristics of the invaded habitat. The information will be very valuable for decision makers to estimate and predict ecological risks associated with environmental Stressors.