When asked by the General Editor to prepare a book-length treatment concerning the nature of the Canary Islands, our aims were rather ambitious. A general monograph was to be written, embracing all the disciplines of natural history applicable to these islands, and over twenty scientists were approached for contributions. However scientists are 'time machines' ; our proposed list of contents has changed a good many times. Cooporation of other authors was gained and, finally, a fairly rounded project appeared revealing different and lesser known aspects of Canary Island Nature. Since Centuries the Canary Islands have attracted the attention of travellers. Earliest reports may be traced back some two thousand years but real scientific investigation began about 1800, the time of Alexander von Humboldt and his visit to the islands; older reports are scarce, sometimes rather confusing because of geographic inaccuracies. But the 19th Century will remain as the century of fundamental explorations, connected with names such as Leopold von Buch, F. C. MacGregor, Sabin Berthelot, Philip Barker Webb, J. Viera y Clavijo, F. von Fritsch, C. Bolle, D. H. Christ, O. Simony, G. Hartung, H. Mayer etc. , all familiar and intimately connected with our knowledge of the natural history of the archipelago. Even the much criticised Ernst Haeckel has provided us with lively descriptions of his visit to one of the 'Fortunate Islands'. The 20th Century brought new interest, new fields to be explored, and new expeditions to the islands.

This book was composed in honour of Dr. Ir. W. G. Beeftink to commemorate his retirement as a plant ecologist at the Delta Institute for H ydrobiological Research, Yerseke, The Netherlands. The editors' main aim has been to collect scientific papers of Wim Beeftink's friends and colleagues. The title of the book: 'Vegetation between land and sea. Structure and processes' was originally proposed by Prof. Dr. W. H. O. Ernst. It was amended by Prof. Dr. J. J. Barkman. In our judgement it reflects the best attempt to cover the numerous and divergent contributions under one heading. Not all papers however fit the "field" covered by the title, and we use this word both literally and metaphorically. We are glad and proud that so many authors went through the strain of the production of a paper, ill' most cases not scheduled, with eagerness. Due to the fact that Wim Beeftink has so many close friends in the field of plant ecology, this fiber amicorum covers a wide range of disciplines covered, in turn, by a great variety of people. The papers range from taxonomy to experimental physiology, from fungi to seed plants, from autecology to synsystematics. Environmental pollution and management studies are also included. The contents of the papers depict Wim's personal evolution as a botanist. Retired professors as well as students are amongst the authors, heads of departments as well as technicians. It proves Wim's ability to be of one mind with all ranks.

The volcanic and oceanic nature of the Canary Islands, its rich plant biodiversity and high rate of endemism, as well as the relict character of some of its plant communities make it a territory of great biological interest. The main geographic, climatic, bioclimatic, biogeographic and floristic features of the Islands are shown and related to the distributional pattern of potential communities along an altitudinal gradient. Current vegetation units and their ecology are described and illustrated with numerous pictures. Potential vegetation units are summarized and comprehensive maps of the potential natural vegetation for each island are given. Human impact on the natural landscape, the occurrence of invasive plants, and the probable impact of climate change on the flora and vegetation are discussed. The conservation status of flora and vegetation are assessed. Four appendixes include a syntaxonomical scheme, a brief history of botanical studies and explorations in the Islands, ethnobotanical notes, and a list of selected literature.