Explains the fundamental causes and effects of acidification in ecosystems and how these can be prevented. Presents evidence on the association of acidification with oxidative processes involving atmospheric oxygen. Describes acidity, pH, and protons, their significance in bioenergetics and the consequent role of autotrophic organisms in acidifying ecosystems. Consolidates information from many diverse sources which it analyzes and reinterprets in relation to the effects on soil, plants and other organisms. Includes a number of case studies for managed and natural ecosystems.