New edition of an introductory text in liminology. Wetzel, who has published extensively on the subject, argues that apart from the structure of water and a few physical properties, aquatic ecosystem structure, energy flow, and productivity are regulated by biogeochemical cycling. Also, he presents data supporting conceptual relationships among biota and the environment, and maintains that regulatory generality prevails across the individual species and diversity of processes, especially concerning regulation of metabolic rates among different communities. The 26 chapters combine lacustrine, reservoir, and running water limnolgy. Illustrated with b&w diagrams and charts. Annotation c. Book News, Inc., Portland, OR (booknews.com)