The appearance of Volume 4 of British Plant Communities brings us near the end of the publication of the results of the National Vegetation Classification. Sustaining commitment and interest through the years has been vital to the continuance of the work and, as coordinator of the NVC and editor of these volumes, I would like to record again my personal gratitude to Donald Pigott and Derek Ratcliffe, the co-chairman of our research team, to John Birks, Andrew Malloch, Michael Proctor and David Shimwell, the research supervisors and to Jacqui Huntley, Elaine Radford, Martin Wigginton and Paul Wilkins for their many and various contributions along the way. More widely, on their behalf, I wish to thank all those others who have assisted in preparing the descriptions of the aquatic, swamp and tell-herb fen vegetation that is included here.

Among the NVC team, it was David Shimwell and Elaine Radford who had particular repsonsibility for producing preliminary accounts of the swamp and fen communities and I was greatly helped by their hard work and experience. For aquatic vegetation, we also benefited from the brief secondment to the research team of Dr Michael Lock who, as well as carrying out some underwater sampling by diving, collated our own data on aquatics and helped with the early characterisation of communities.

We were fortunate, too, while working on these vegetation types to have Mrs Margaret Palmer as the Nominated Officer for the project within the Joint Nature Conservation Committee. She was already playing an important role in developing other methods for the survey of standing waters in Britain and, as well as being given access to the data which a range of projects had produced, we were much informed by her wide experience and through her comments on our work.

Among others involved in those projects, we are especially grateful to Dr Kevin Charman and Messrs Martin Alcock and Clive Doarks. Drs Terry Rowell and Nigel Holmes also made valuable comments on the manuscript at various stages and we had informative discussions, too, with Mr John Ratcliffe and Ms Ros Hattey of the then Welsh Lowland Peatland Survey, Dr John Harvey of the National Trust, the Reverend Gordon Graham of the Durham Flora Project and the late Professor David Spence, whose enthusiastic understanding of aquatic vegetation is greatly missed by all of us.