From Archive to Map to Pastoral Landscape: A Spatial Perspective on the Livestock Ecology of Sixteenth-Century New Spain

Abstract

The European invasion of the Americas rejoined two ecosystems that had been diverging since the Pangean supercontinent fragmented some 200 million years ago. On a hemispheric scale, exotic pathogens exploded through native populations, Old World biologies and institutions filled empty niches to bursting, and capitalists commodified landscapes, accumulating space and extinguishing species. On a regional scale, much still remains unclear, especially the initial ecological effects and processes of what Alfred W. Crosby labeled the Columbian Exchange.' Because Spain established the first substantial European presence in the New World using livestock integral to frontier expansion, the ecological effects of cattle and sheep in sixteenth-century New Spain remain as central to environmental history as a comprehensive evaluation of those effects remains elusive and controversial. For New Spain, now central Mexico, some scholars have claimed a leading role for livestock in the ecological upheaval; others have just as persistently denied it. In the former view, a metaphorical plague of sheep and cows pervasively degraded the environment. An exponential increase in livestock densities resulted in extreme overgrazing, a decrease in vegetation cover, more frequent and greater floods, and dramatic soil erosion. In the latter view, the introduction of livestock coincided with environmental recovery. By the time the Spaniards arrived in 1519, high population densities were already testing environmental thresholds, with native agriculture periodically disrupting vegetation cover and causing the erosion of soil from hillside fields. As native populations declined in a series of sixteenth-century