Optimal use of ethnobotanical resources by the Mountain Pima of Chihuahua, Mexico.

Abstract

The Mountain Pima of the Sierra Madre Occidental of Chihuahua, Mexico, utilize a variety of domesticated and nondomesticated resources. Part of their agricultural system consists of shifting, or swidden, cultivation on steep hillsides. Wild edible plants contribute significant amounts of vitamins and minerals to the diet on a seasonal basis. The drought of 1988 caused a decrease in the availability of many resources, but an increase in availability of roots of saraviqui (Prionosciadium townsendii). A dynamic, nonlinear optimization study of Mountain Pima diet included requirements for adequate amounts of energy, protein, calcium, and vitamins A and C. Oxalate content of several plant foods and seasonal variation in resource availability were incorporated into the study. Two methods were compared: time minimization and a nutrient indexing method minimizing the product of the absolute value of the natural logarithm of the ratio of recommended intake to actual intake rates. This method allowed simultaneous optimization of several different parameters. The nutrient indexing model matched the actual diet of the Mountain Pima somewhat better than the traditional energy minimization model. It predicted higher use of noncultivated plant species and of animal resources than the time minimization model. Analyses were conducted for years of adequate rainfall and for the drought year. A list of 612 plant species collected in the community of Nabogame is also included.