This publication serves as a guide to activities and strategies in environmental education. Lesson plans include objectives and suggested procedures in dealing with the following environmental concepts: (1) The earth is a vast but limited natural system; (2) The total environment is in constant change; (3) A living thing is the product of its heredity and environment; and (4) All living things, including man, are interdependent with one another and with their environment. The activities vary in complexity and amount of student activity. (Author/RH)