As a text for college courses in the conservation of natural resources, this book employs a biological (ecological) approach to the environment and environmental problems. Objectives of the material are to bring out: (1) the value of natural resources; (2) the gravity of the environmental crisis; (3) the principles of ecology which underlie natural resource management; (4) the techniques and policies by which resources can be managed effectively; and (5) to instill a sense of the urgency of our conservation crisis, and the extent to which the public can participate in solving it. Current coverage of recent national developments is given together with the responsibilities and programs of the various federal agencies concerned with conservation. Case studies are used to illustrate conservation principles and both sides of controversial questions are presented. Numerous photographs, diagrams, and charts visually supplement the narrative material and bibliographic references follow each of the 16 chapters. (BL)