Humans instigate and respond to rapid changes in natural environmental conditions in a complex set of ways. The process of soil degradation, for example, traditionally has been studied largely in natural and physical terms, with emphasis placed on the loss of soil material, declining fertility, and changing vegetative sustainability. Complete understanding of the process of soil degradation also involves the study of human activity, however, because much of the loss and deterioration of soils results directly from human activity. Furthermore, as soils degrade, agriculture and other human endeavors must change. This project examines not only those direct links among human, natural, and physical systems; it also looks interactions one step removed on order to determine how human and environmental forces relate to each other. The project will consist of a comparative study of soil degradation in three districts of eastern Bolivia. Soil erosion will be estimated using direct measurements in sample plots and through analysis of aerial photographs. These photographs and field observations also will be used to measure changes in land use, which will be analyzed in conjunction with the soils data in order to evaluate associations between land-use change and soil erosion. Complementary analyses will integrate socio-economic data for the last few decades and information gathered from interviews and oral histories to assess social causes of practices that have promoted soil degradation and the degree to which soil degradation has become an important political issue within Bolivia and in terms of its dealings with other nations. The results of this project will be valuable at a number of levels. Specific information gathered in the study area will increase understandings of human-environmental interaction in this politically volatile region. The broader conceptual base within which this study is set is global in nature, however, and the Bolivian conclusions will complement results from related studies conducted elsewhere, thereby enhance our broader knowledge of the human dimensions of global environmental change.
