American Scientist

Changing Fortunes: Biodiversity and Peasant Livelihood in the Peruvian Andes. Karl S. Zimmerer. 308 pp. University of California Press, 1996. $45.

For some time, discussions of foodcrop biodiversity have focused on the forested humid tropics, particularly those of Asia. With the publication of Changing Fortunes, cultural geographer Karl Zimmerer has succeeded in establishing the Andes mountains of South America as a major hearth of rich biodiversity. This detailed historical and contemporary study explains how farmers of the Paucartambo valley, on the eastern edge of the Andes, manage a huge variety of landraces (indigenous varieties) of the key subsistence crops of potatoes, maize, ulluco and quinoa. For hundreds of years Paucartambo farmers have selected seed to diversify ripening times in this mountainous environment that is notable for both short growing seasons and marked diversity.

Over time the forces of colonization, urbanization and the market have worked against farmers' attempts to maintain landrace diversity. The Incan state forced peasants to take land and labor from subsistence production to cultivate crops for ceremonial ends. Even as the Spanish Conquest ended Inca hegemony and the demands of ceremonial production, Spaniards introduced their prized crops of 16th-century Castile: wheat, barley, broad beans and peas. In the 20th century, expanding large landholdings, haciendas, and a growing regional capital, Cuzco, brought Paucartambo into the orbit of the market.

The net result of these forces has been the successive loss of biological diversity. Zimmerer's explanation of the process is much more subtle and nuanced than the facile generalizations of unilinear loss that are so common today. For example, he shows that from 1969 to 1990 genetic erosion rarely occurred because an individual crop was replaced or an improved variety added to a field sown with landraces, but rather because landrace-rich fields were abandoned or transformed for the market-oriented production of specialized varieties of early potatoes and barley.

Another, somewhat more controversial theme presented in Changing Fortunes is an association between landrace diversification and economic stratification. Zimmerer sees this taking place because of agrarian class formation and differential access to the means of production. Wealthy farmers and, to a much lesser extent, poor farmers, are more likely to seed the diverse crops. In contrast, middle holders, who are highly constrained in their use of their labor, land and capital, are the least apt to seed diverse crops. This rather surprising and provocative hypothesis merits further research and testing with historic and ethnographic materials.

In Paucartambo Zimmerer also finds evidence of the clustering of production in a distinctive irregular mosaic of farm spaces. The flexible land use of Paucartambo farmers contrasts with a well-known pattern in the central and western Andes, and in other regions of tropical high mountains, of non-overlapping, elevation-conforming production tiers. A more sophisticated understanding of montane agroecology is now emerging from Zimmerer's research and that of others. On the one hand, extremely varied and complex montane settings display a patchy—that is discontinuous—distribution of microenvironments with adequate moisture, productive soils and frost-resistance necessary for agriculture. The knowledge necessary to manage land, labor, water, crops and landraces in these field clusters is highly localized. The ethnographic literature for the Andes, Bali, the Himalayas and other regions of tropical high mountains is replete with references to communal and lower-level group decision-making. The inclusion of the discussion of social structure and cultural configurations gives more depth to Zimmerer's analysis of crop and landrace management. If he could also bring information on the social organization into the picture, there would be further payoffs.

On the other hand, geoecological research has shown that altitude, climate and soil fertility interact to set upper limits on pastoralism and agriculture and, within the latter, upper limits on the types of crops. The resulting concept of vertical lifezones can lead to an excessively deterministic and static view of natural-resource management. For this reason, the incorporation of "patchy" agroecology in discussions of tropical high mountains as hearths of biodiversity is a welcome development.

Changing Fortunes is a well-researched and much-needed analysis. Overall, the picture is not heartening. Although many sound practices, such as mixed subsistence production, land and crop rotation, natural fertilization and mixed agro-pastoralism remain, their hold is tenuous. Andean farmers are finding good stewardship increasingly difficult to maintain in the face of the pressures and attractions of commercial farming.—David Guillet, Anthropology, Catholic University of America