Examples used to illustrate basic concepts in limnology are drawn from all over the world - North, South and Central America, Africa, New Zealand, Japan, Europe, Antarctica and the Arctic. This wide array of examples allows the authors to point out marked differences in size, basin shape, climate and biota and yet illustrate a unity of principles in this science. The second edition is extensively updated to reflect the changes that have occurred over the last decade. There are two new chapters on wetlands and another on large rivers, as a response to the emerging trend for limnologists to broaden their horizons beyond lakes and streams. The chapters on light and phosphorus were completely rewritten and the chapters on phytoplankton, zooplankton and food chains have been extensively revised.