Wetlands are among the wildest places on Earth. Used throughout the years as a valuable means of transportation and communication and as a source of food, wetlands are found in a wide range of geological settings in almost all parts of the world, and they occupy about six percent of the world's surface. ""Wetlands, Revised Edition"" provides broad, up-to-date coverage of this unique ecosystem - including information on the global cycling of water, which will become an increasingly scarce resource in coming decades, and on the relationship between the water cycle, rock weathering, and wetland formation.This accessible book examines the diversity of wetlands in the past, present, and future, how they work, and how they can be conserved. This revised edition features information on the development of wetlands and the techniques used in their study, such as radiocarbon dating and pollen analysis. The section dealing with the future of wetlands in a world of rapid environmental change has been brought up to date, and accounts of how individual species cope with life in the wet have been expanded. All-new full-color photographs, illustrations, and sidebars help readers gain a valuable understanding of this important topic.