Ozone levels are injuring trees and other plants. Thirty species of plants showed leaf damage after being exposed to controlled ozone levels identical to those that occur in the park. To further quantify ozone injury to plants, permanent monitoring plots were set up in the park. In general, researchers have found that ozone exposure and damage to plants are worse at the higher elevations. They have also documented that up to 90% of black cherry trees and milkweed plants in numerous park locations show symptoms of ozone damage. Some of the other plants that show ozone damage symptoms include tuliptree, sassafras, winged sumac, blackberry, and cutleaf coneflower.
Acid Rain, Acid Clouds, and Nitrogen Overload
Plants and animals in
Research shows that certain high elevation soils in the park are receiving so much airborne nitrogen that they are suffering from advanced nitrogen saturation. This condition limits the availability of forest nutrients, especially calcium, to plants and causes the release of toxic aluminum that can hurt vegetation and streamlife. Mountain streams and forest soils are being acidified to the point that the health of the park’s high elevation ecosystems is in jeopardy. Nitrate levels in some streams are approaching the public health standard for drinking water.