In the mid 1970s two events led me to get to know the Yorkshire Dales better than I had previously. Since 1964 I had been to the Malham Tarn Field Centre with groups of students, first from the University of Edinburgh and then from the University of York, and my family very much enjoyed the summer days we spent amid this magnificent hill scenery. In 1976, the British Ecological Society and the National Trust jointly worked on a survey of the biological interest of the National Trust properties of the Kent, East Anglian and Yorkshire Regions. Malham Tarn itself, and the surrounding farms, formed one of the twenty properties of the Yorkshire Region. I spent the bank holiday, that commemorated the Queen's Silver Jubilee, at Malham, looking fairly closely at the National Trust's landholding there. Miss Sarah Priest, who also looked at the National Trust properties, and I produced a report in late 1977, attempting both to describe and to evaluate the nature resources of the National Trust in Yorkshire. In the following year, 1978, the Nature Conservancy Council wanted to survey the whole of the upland area that was known as the Malhaml Arncliffe SSSI (Site of Special Scientific Interest). A contract to look at such an exciting area, considering where boundaries should go, and looking to see if there were important areas of habitat that should be brought within the SSSI, was a superb practical antidote to an office in the University.

Succession-nothing in plant, community, or ecosystem ecology has been so elaborated by terminology, so much reviewed, and yet so much the center of controversy. In a general sense, every ecologist uses the concept in teaching and research, but no two ecologists seem to have a unified concept of the details of succession. The word was used by Thoreau to describe, from a naturalist's point of view, the general changes observed during the transition of an old field to a forest. As data accumulated, a lengthy taxonomy of succession developed around early twentieth century ecologists such as Cooper, Clements, and Gleason. Now, nearer the end of the century, and after much discussion concerning the nature of vegetation communities, where do ecologists stand with respect to knowledge of ecological succession? The intent of this book is not to rehash classic philosophies of succession that have emerged through the past several decades of study, but to provide a forum for ecologists to present their current research and present-day interpretation of data. To this end, we brought together a group of scientists currently studying terrestrial plant succession, who represent research experience in a broad spectrum of different ecosystem types. The results of that meeting led to this book, which presents to the reader a unique summary of contemporary research on forest succession.