The Amazon -that name was given to the biggest river on earth and is often used for the whole area of its basin too. This geographical region is currently referred to as Amazonia, thus emphasizing the peculiar character of its aquatic and terrestrial reaches. The Amazon embodied the dream of many a naturalist to explore what for a long time was a terra incognita. In recent years, however, Amazonia has emerged as a main centre for 'development' by some of the countries in which it lies and by foreign industrialized nations. The development projects and enterprises have aroused woridwide interest and have given rise to discussions on their aims and their consequences to the Amazonian nature. Limnological and ecological investigations in Amazonia started only about 40 years ago. The editor had the good fortune to partake in them from the very beginning. He spent his decisive years in Amazonia, and dedicated his life's work to that research and to that country and the Amazonian people. Nearing the end of his scicntific activities, hc is gratcful to bc ablc to summarizc in this book most of the knowledge we possess at present of Amazonian limnology and landscape ecology.