Describes the major vegetation types of North America and their ecological basis, emphasizing such environmental factors as climate, soil, topography, and fire. Part 1 outlines the basics of vegetation science (such as composition, structure, function); Part II considers each type of vegetation in terms of the background material in Part I. Examines major plant communities and dominant species, emphasizing species adaption to show the interrelationship between vegetation and environment. Each vegetation chapter concludes with a section on human impact. Includes suggested readings and over 125 illustrations.