Abstract :
This paper presents an ecosystem-based approach to risk assessment in freshwater wetlands. The key concept in this approach is that the primary biotic and abiotic components that determine the structural and functional characteristics of wetlands are inseparable. Each component should be identified and its contribution to ecosystem functions or human values determined when deciding whether a stressor poses an unreasonable risk to the sustainability of a particular wetland. Understanding the major external and internal factors that regulate the operational conditions of wetlands is critical to risk characterization. Determining the linkages between these factors, and how they influence the way stressors affect wetlands, is the basis for an ecosystem approach. Adequate consideration of wetland ecology, hydrology, geomorphology, and soils can greatly reduce the level of uncertainty associated with risk assessment and lead to more effective risk management. In order to formulate effective solutions, wetland problems must be considered at watershed, landscape, and ecosystem scales.
