Click on these thumbnail images to see full size image. The effect of acid rain on terrestrial and aquatic environments is determined by the acidity of the precipitation and by the geology of the soils and rocks of the area. Different types of soils and rocks have different abilities to neutralize or buffer the acid. Certain types of soils and their associated water ecosystems are particularly sensitive to acid rain because of their low buffering abilities. In general volcanic rocks, and thin topsoils have poor buffering abilities.
Acidity is measured on the pH scale.
A pH value of 7.0 is neutral, and anything less than 7.0 is acidic. The pH scale is logarithmic, which means that the difference between a pH of 6 and a pH of 5 is a ten-fold difference. The ecosystem of a lake is severely affected when the pH falls below 5.0. At this level, fish, invertebrates, and plankton die. Click on these thumbnail images to see full size image.