9Wetzel's Limnology: Lake and River Ecosystems, Fourth Edition, presents a fully updated revision of the classic textbook Limnology: Lake and River Ecosystems - last published in 2001. The coverage has been thoroughly updated with recent research and theoretical developments. Each chapter of this edited volume has been written by an expert, or team of experts, providing a comprehensive and global perspective, with the editors working closely with the authors to maintain continuity within and between the chapters. This is not only an essential textbook for undergraduate and graduate students in limnology but also a standard reference book for seasoned limnologists and other scientists.