Ecosystem protection and restoration in the U.S.: Using air pollution thresholds to communicate public policy choices

Background/Question/Methods

Understanding where thresholds lie can be invaluable to good stewardship of natural resources and ecosystems, because when approaching problems are recognized there may be an opportunity for preventing undesirable ecosystem changes. Once a species or ecosystem has passed a tipping point, it may not be possible to return it to its pre-existing state, and resiliency to respond to other stressors may also be lost. Ecosystems impacted by air pollution represent an ideal vantage point to explore the topic of ecosystem thresholds, as the effects of air pollutants on ecosystems are relatively well studied and deposition critical loads of air pollutants are gradually gaining acceptance in the U.S. Air pollution thresholds can be based on scientific research (ecological thresholds) or on a balance of other considerations spanning law, economics, ecological effects, human health and risk assessment (policy thresholds). The development and use of air pollution thresholds for ecosystem protection and management are increasing in the United States yet threshold approaches remain underutilized.

Results/Conclusions

This poster will present some of the tools (conceptual diagrams, summary tables, illustrations) we are using to communicate the value of thresholds approaches to non-technical audiences and to encourage use of ecological thresholds in policy and land management planning efforts. These tools include a framework for linking ecosystem services to thresholds of air pollution; a conceptual diagram using pictures to illustrate variability in community responses to air pollution levels; and national-scale critical loads maps.