My goal has been to write a text that introduces students to ecology and provides a rigorous assessment of some key environmental issues. The first half of the text provides a strong introduction to basic ecological concepts and theories without overwhelming the student with mathematics. Building on that secure scientific foundation, the second half of the book provides a critical evaluation of the cause and ecological effect of well-publicized environmental issues, such as global climate change, acid deposition, loss of biodiversity, and genetically modified foods. Each topic is investigated from a scientific rather than an activist viewpoint and is written to stand alone. Although most ecological concepts are presented early in the book, some more advanced ideas such as island biogeographic theory and metapopulation dynamics are woven into later chapters. Throughout the book natural selection, ecosystem change, and scientific method are emphasized. I have used this text with non-majors with no previous background in biology, and with sophomore biology majors. In both cases the students liked the book because they found it concise but readable. The third edition has been reorganized to provide discrete sections on population ecology and community ecology. The various concepts introduced in these chapters are brought together in synthetic chapters such as Chapter 11 on Fisheries and Chapter 18 on habitat fragmentation. An author has a natural urge to include more examples, thereby producing a larger and larger text. While introducing many new ideas to the text I have consciously tried to keep the text compact. Although this edition features one new chapter on biodiversity, two chapters on tropical ecology have been deleted. Many of the chapters contain new case studies, and the chapter on global climate change has been completely rewritten. The recommended readings at the end of each chapter have been updated and slightly expanded. This list of literature is not meant to be exhaustive, but contains a mix of classic papers, conflicting viewpoints, and accessible summaries of related ideas. The text is supported by a variety of on-line resources. The accompanying Web-site is organized around the chapters in the book. You will find self-grading quizzes and a set of hotlinks to Web pages that I have found useful and accurate. The hotlinks access the Web sites of select governments, universities, and reputable organizations. If you find more that should be included (or ones that no longer exist), please let me know firstname.lastname@example.org. Please remember that these sites are not refereed and should not be given the same credence as the primary literature. Teachers will also have access to all line drawings from the text as downloadable graphics files that could be plugged into powerpoint presentations or could be printed direct onto transparencies. I have learned much as I researched these chapters, frequently heading from the keyboard into the classroom to try out a new line of thinking on my students. I hope that some of my enthusiasm shines through in the text. A textbook is no substitute for an effective teacher, but it should be a valuable ally to teacher and student alike, providing a common baseline of knowledge. I believe that a textbook should be topical, relevant, and interesting to read. Although scientists must learn facts, I have tried to emphasize the concepts and examples of ecology, and why it is relevant to our everyday lives, rather than produce an encyclopedia of indigestible statistics.Bush, Mark B. is the author of 'Ecology of a Changing Planet', published 2002 under ISBN 9780130662576 and ISBN 0130662577.