The way in which livestock are grazed on these lands dictates where the pasture falls on the spectrum between healthy soil and sand.
"It has been shown elsewhere that moderate levels of grazing are associated with higher biodiversity (Forsyth 1983, Shi et al. 1991, Belsky 1992, Bian et al. 1994, Agricultural Research Service 1999), and that plant biodiversity is associated positively with plant resistance to and recovery from drought (Tilman and Downing 1994), with grassland productivity (Tilman et al. 1996), and with resistance to invasion (Hobbs and Huenneke 1992, Tilman 1997). At high grazing intensities, however, there usually is a decrease in the abundance of palatable species, a decrease in overall plant productivity, and a decrease in total ground cover (Skarpe 1991, Fuls 1992). Clearly, any level of grazing also will affect the community structure, species composition, and the quality of grassland plants (Mattson 1980, Milchunas et al. 1988, Huntly 1991, Fernandez et al. 1992). In fact, some species are even maintained by sustained grazing (McNaughton 1979, 1985). Thus, as McNaughton (1979) explains, an optimum defoliation level is anticipated (Noy-Meir 1975; Caughley 1976), an optimum reached only when livestock grazing closely mimics the spatial and temporal patterns of wild ungulates. Otherwise, the land usually changes beyond recognition. Grazing systems therefore must have inherent flexibility and mobility to ensure quick responses to fine-scale spatial and temporal heterogeneity in the grassland. In highly variable environments like the Tibetan plateau, only this kind of land management system can be maintained in the long-term (Scott and Kong 1990, Skarpe 1991, Chen 1997)." -- Chapter 2 of Marc Foggin's Ph.D. Dissertation (link at top)
"According to Goldstein and Beall (1990; also see Meiners 1991, Schaller 1998), nomads rotate their livestock to different parts of the pasture over shorter time scales as well. This movement allows the vegetation to regenerate for several days before being subject to further grazing. And over longer periods, a land management system traditionally was used in some parts of the Tibetan world by which pastures were redistributed among pastoral families every three years based on herd sizes and known carrying capacities of the land." -- Chapter 2 of Marc Foggin's Ph.D. Dissertation (link at top)
"Since the early 1950s, the government has introduced many new ideas and methods of �development� into the entire region. Collectivization in the late 1950s and 1960s transferred livestock ownership and decision-making processes from individual households and monastic institutions to state communes and distant centralized authorities. Many traditional systems of rangeland management that prevented overgrazing were abandoned (Clarke 1987, Goldstein et al. 1990)." -- Chapter 2 of Marc Foggin's Ph.D. Dissertation (link at top)
"Intensification of livestock production therefore has progressed concurrently with serious ecosystem degradation (Wang 1980, Hu et al. 1992, Qinghai Census Bureau 1994) that only recently has been acknowledged on a wider scale (He 1997, Han 1999, New reserve 2000)." -- Chapter 2 of Marc Foggin's Ph.D. Dissertation (link at top)
"Finally, small scale, household-focused privatization in China ignores the fact that resource management at larger spatial scales may be the best possible institutional response to large environmental variability of arid and semi-arid lands (Thompson and Wilson 1994)." -- Chapter 2 of Marc Foggin's Ph.D. Dissertation (link at top)