Presents an overview of some of the advances in ecosystems analysis which occurred during the involvement of the United States in the International Biological Program. (PB)

Discusses environmental and biological aspects of arctic and alpine vegetations in the New World between the equator and the Arctic Ocean, considering their similarities, differences, and susceptibility to disturbance by man. (JR)

Discusses the effects of radioactive wastes on marine communities, with particular reference to the fitness of populations and the need for field and laboratory studies to provide evidence of ecological change. (JR)

Offers a contemporary analysis of the interaction of man and the rest of the biota. Suggests that the dependence of man on nature is, more than the crisis of energy and world economics, the emergent scientific and political issue of the next years. (JR)

Examines aspects of competitive exclusion, which develops when two species jointly utilize a vital resource that is in short supply. When this occurs, one of the species will eventually eliminate the other from the habitat where their distributions overlap, unless one or both species evolve differences that reduce competition. (JR)

Recounts some of the progress that has been made in the field of population biology. Presents some of the important advances made in the field, along with some of their applications to societal problems. Calls for more cooperation between population scientists and social scientists, and more environmental education for the public. (TW)