Vegetation dynamics is an important subject. A knowledge and under­ standing of it is central to the science of vegetation management-in grassland, range and nature reserve management, and in aspects of wildlife management, forestry and agricultural crop production. It is also a large and diffuse subject. In a small book such as this I had to be highly selective, and could not do equal justice to all aspects. I have had therefore to condense many examples, and more regrettably, many arguments. While I have tried to present a broad selection of topics and examples, the content inevitably reflects my own special interests and experience. The study of vegetation and its dynamics does not lend itselfto neat and tidy divisions, and the way of allotting material into different chapters here is arbitrary. I have used Chapter I to introduce a number of ideas, beginning with the nature of vegetation in space, then passing to an introduction to the nature of changes in vegetation with time, in particular those generally known as successions. The book also contains a number of asides to the text's central arguments; I hope the reader finds these interesting rather than disconcerting.