The Dynamics and Future Scenarios of the Animal Husbandry System in Khutag-Undur from 2015 to 2050

Under the conditions of climate warming, grassland degradation, frequent sandstorms, and fast increases in livestock numbers, coordinating animal husbandry and ecological protection is an important issue facing Mongolia. Using Khutag-Undur as an example, this study explores the dynamic process, future scenarios, and optimization strategies of the animal husbandry system in a typical Soum of Mongolia from 2015 to 2050 under three future climate socioeconomic scenarios of CMIP 6: SSP1-RCP2.6, SSP2-RCP4.5, and SSP5-RCP8.5. First, the animal husbandry system was deconstructed into three subsystems: grassland primary production, livestock secondary production, and herder consumption. Based on the negative feedback mechanism of forage-livestock balance, a system dynamics model for the Khutag-Undur Soum animal husbandry system was developed. This model integrates spatial data such as land cover and NPP, as well as statistical data on livestock, herder income and expenditures, sample plot surveys, and herder questionnaires. The model was used to simulate the historical changes (2015–2022) in forage production and carrying capacity, livestock stock, and livestock output of Khutag-Undur, and then to forecast the future scenarios of those variables for 2022–2050. Second, the most suitable future scenario for the Soum was identified by comparing the three future scenarios using a pastural system sustainability evaluation method. Finally, based on three indicators of livestock numbers, a two-step livestock reduction strategy was proposed. The main conclusions are that the rapid growth of livestock numbers in Khutag-Undur places considerable pressure on the grassland, and the SSP1-RCP2.6 scenario is the most suitable future scenario for the Soum. However, even in this suitable scenario, grassland overloading remains evident. The continuous implementation of a livestock reduction strategy is recommended to maintain the sustainable development of animal husbandry and grassland conservation.