El objetivo del trabajo es contribuir al conocimiento de la arquitectura del pastoreo en los Andes. El foco regional del estudio es Huancar en el Departamento Susques (Jujuy, Argentina). En primer lugar se describen los sistemas de asentamientos vinculados con las actividades pastoriles de Huancar y luego se presentan los esquemas del uso del espacio por parte de los pastores. Finalmente, se analizan los significados que el espacio tiene para los pastores

Overview of the rangelands of the Jianshe region of China which discusses the environmental and social issues associated with the pastoralist land use in the area.

Since the early 1970s, the position of pastoralists in West Africa's Sahel zone has become ever more precarious. Their plight is evidenced by rural-urban migration movements as well as the results of field surveys. The last major drought of 1983-1985 delivered a major blow to communities which derive most of their food and revenues from herding. In many rangeland areas there is civil unrest - even building to armed conflict in places - owing to mounting tensions between various pastoral groups.

For over a hundred years the zone of Kisha Beiga, in Burkina Faso, was plagued by ethnic conflicts, revolution and political anarchy. Local rivalries and administrative chaos put paid to any efforts to manage natural resources efficiently. Then, in 1991, the Burkinabe Sahel Programme (PSB) set out to quell factional rivalry and establish sustainable resource-management in the area. A fragile consensus has been achieved, but it has not been easy. Leadership conflicts, land tenure issues and administrative anomalies have threatened to derail the project.

Arid shrub-lands in Syria and elsewhere in West Asia and North Africa are widely thought degraded. Characteristic of these areas is a preponderance of unpalatable shrubs or a lack of overall ground cover with a rise in the associated risks of soil erosion. Migrating pastoralists have been the scapegoats for this condition of the range. State steppe interventions of the last forty years have reflected this with programs to supplant customary systems with structures and institutions promoting western grazing systems and technologies.

Potential vegetation environments (e.g., habitat types, range sites, ecological sites) are important to land managers because they provide a conceptual basis for the description of resource potentials and ecological integrity. Efficient use of potential vegetation classifications in regional or subregional scale assessments of ecosystem health has been limited to date, however, because traditional ecological unit mapping procedures often treat such classifications as ancillary information in the map unit description.

The objectives of this Colorado study were to assess primary reasons ranchers choose to stay or sell the ranch, compare the motivations for ranching between a traditional agriculturally based county and a rapidly developing county, and assess whether factors such as length of tenure, fiscal dependency on ranching, and dependency on public lands play roles in decisions to sell. Personal interviews were conducted with 37 ranchers. While land use conversion occurs for a wide variety of reasons, lack of heirs and detrimental public policy were important reasons given for selling ranches.

In Utah during the early 1990s it was theorized that substantive change was under way in the management of private grazing land. Change was thought to be spearheaded by grazing permittees who feared losing access to public forage and thus wanted to increase carrying capacity of private grazing land as a hedging tactic. We synthesized results from socioeconomic surveys conducted among a target population of 5,067 grazing livestock producers during 1993, 1996, and 1997.

Aims: The aim is to determine the risk of transmission of BSE to humans and cattle through the application of sewage sludge to agricultural land. Methods and Results: A quantitative risk assessment based on the Source-Pathway-Receptor approach is developed. Central to the model is the estimation of the arithmetic mean concentration of BSE agent in sewage sludge.