The Pennsylvania Department of Environmental Protection – Bureau of Air Quality

Click here to visit the Pennsylvania Department of Environmental Protection's Bureau of Air Quality website.

The United States Department of Agriculture – Forest Service

Click here to visit the USDA Forest Service website.

PA Department of Conservation and Natural Resources - Bureau of Forestry

Click here to visit PA Department of Conservation and Natural Resources website.

Department of Forest Pest Management

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Switzerland

Click here to visit the Ozone Air Pollution and Effects on Native Plants in Switzerland project website.

Click here to visit the Swiss Federal Institute for Forest, Snow and Landscape Research homepage.

Spain

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Italy

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