3. Mongolian Nomadism and the Relationship Between Livestock Grazing, Pasture Vegetation, and Soil Alkalization

Grassland covers approximately 75 % of Mongolia, which is characterized by a dry, cold climate, and most of this grassland is used as pasture. Although they are vulnerable, people have lived in the grasslands as nomadic herders for thousands of years, suggesting that the relationship between livestock grazing and pasture vegetation has historically been sustainable. Since the twentieth century, however, the social system and the nomadic circumstances of herders have changed dramatically through a rapid shift to socialism and democracy. In recent decades, the number of livestock (particularly goats) raised to produce cashmere for export has increased rapidly, and herders have concentrated in areas surrounding the capital city and along main roads leading to the capital. These changes, which reflect a shift from nomadic traditions to unsustainable practices, have resulted in the degradation of pasture vegetation. Large herbivores, including livestock, have significant direct and indirect effects on ecosystem structure and function. However, livestock products are an essential part of the Mongolian economy and the livelihood of large numbers of people. It is therefore important to assess the direct and indirect effects of livestock grazing on pasture ecosystems to promote both conservation of natural ecosystems and sustainability of residents and their livelihoods. To obtain a better understanding of the direct effects of livestock grazing, I have used the fecal accumulation rate technique to estimate livestock density on a small scale, and to estimate livestock grazing rates. The data obtained in this study suggest that grazing rate is generally constant, but that it can vary depending on total production of pasture plants. To understand better the indirect effects of grazing, relationships between soil alkalization, livestock grazing pressure, and pasture vegetation were examined. I conclude that overgrazing can cause soil alkalization, and that soil alkalization may delay the recovery of degraded pasture vegetation. Thus, it is important to consider the variability of the grazing rate and to manage grazing intensity and prevent soil alkalization to achieve sustainable use of pasture.