In the past, research into succession has concentrated on the widespread communities of grassland, herbfield and forest. However, the initial stages of a community are associated with algae, lichens and mosses, and despite their importance as primary colonizers, little attempt has been made to include the microbial community and its effects within the framework of primary succession. Accepting that it is at the microscopic level that any consideration of primary succession must start, this volume draws together microbiologists, ecologists, botanists and zoologists into a more coherent discussion of the early stages of community development. New techniques allow observation and experimentation at the microbial level, and the ecological opportunities offered by the Mount St Helens eruption have been exploited to shed more light on the processes of primary succession.