A description and discussion of herder communities, grassland ecology, livestock systems and animal production in Mongolia and Inner Mongolia are provided. The description includes reference to specific grazing trials. An overview of the modelling designed to capture some of the complexities of these systems is provided. The bioeconomic sustainable grazing model used to estimate environmental benefits of changed production systems under alternative policy settings model, and referred to in Chapter 7 and elsewhere in the book, is introduced. Income and livelihood impacts of changing production systems under different market and environmental conditions are reported.