Desertification Emerges through Cross-scale Interaction

摘要

Desertification, which causes irreversible loss of productivity in drylands, is one of the most urgent global environmental threats. Desertification emerges through a complex process at the local scale, and prevails at a large scale. Complexity and largeness are difficult to understand simultaneously; therefore previous desertification studies have been separated according to scale. This study demonstrates the cross-scale nature of desertification by showing the current state of desertification at the large scale through remote sensing and examining the spatial arrangement of herders' camps and level of desertification through modeling. These two results can describe the cross-scale nature of desertification in Mongolia, i.e., a political regime change has caused herders to concentrate in specific locations, thus modifying piosphere dynamics. Such modification has caused desertification to progress, resulting in a belt-like desertification at the large scale. By understanding the cross-scale nature of this phenomenon, rangeland management plans at the national level can specifically include instructions on how the herders' day-to-day land use should be organized to prevent desertification at the large scale. This study suggests that an explicit linkage between the current activities of herders' groups and the current belt-like desertification can improve rangeland management planning in Mongolia.