We have edited this book in honour ofMakoto Numata, the nestor of Japanese plant ecology, who will celebrate his 65th birthday in November 1982 and will be retiring from office in March 1983. As the main concern of his work during the last years was to educate people in ecological understanding - probably the only possibility for mankind to master the 'environmental problems' - the topic chosen for this book seemed the most suitable one to honour the retiree. We hope that this volume will prove to be useful for many in carrying through this important task of modern ecology. We are grateful to the authors and particularly to Mr. Peters and the staff of Dr. W. Junk publishers for their patient cooperation. We are also indebted to Jan Knaapen for making the index. Wien, Utrecht and Chiba, June 1982 The Editors VII Contents Preface.................................................................................................... VII List of contributors....................................................................................... XI A biography of Makoto Numata by I. Ikusima ........................................................ .