This text provides an in-depth analysis of the ecological relationships in the northern part of the world's largest wetland in a near-natural state. It offers a survey of the flora and fauna of the region, which should make it particularly interesting for researchers in biodiversity and the biogeography of the Neotropical Region. It surveys this vast area of seasonally flooded plains of all major taxa of plants and animals, providing data obtained during a study lasting nearly four years and information available in myriad short publications in journals, many of which are hard to obtain. The book should be of interest to researchers in the wet-and-dry climatic zone of the tropics worldwide and to ecologists in South America in particular. It is meant to be a basic sourcebook of tropical ecology and wetland biology.