The Changing Mile Revisited

Abstract : The book explores the respective parts played by man and climate in altering the face of the arid regions of southern Arizona and northwestern Mexico. The major portion of the volume is comprised of plates in which landscape photographs taken in the 19th and early 20th centuries are compared with modern photographs exposed, as nearly as possible, from the same aspects. A review is given of the salient features of the desert habitat; and the influences of man (Indians, Spaniards, Mexicans, and Anglo-Americans) on this ecosystem are discussed in detail. Individual attention is given to the repeat- photography analysis of each of the important vegetative provinces: oak woodland, desert grassland, and desert. General patterns of change are discussed, and some hypotheses concerning vegetation change are offered.