Keep sustainable livestock production without Grassland degradation: Future cultivated pasture development simulation based on agent-based model

Abstract

Overgrazing on grasslands has caused grassland degradation in China during past decades, which could impair the production of livestock products, so it must be limited to maintain the supply ability of grasslands for human well-beings. Establishing cultivated pastures, which has been popularized and proved effective to increase forage yields and restore degraded grasslands in many developed countries, could also provide more powerful support for livestock production with a healthy livestock-grassland relationship in China where there are only few cultivated pastures now. To explore whether cultivated pasture construction is a promising approach for mitigating ecological pressure while satisfying herdsmen livelihood demands, we developed an Agent-Based Model based on herdsmen behaviors and grassland conditions. In this model, the cultivated pastures in future 30 years will be established by herdsmen in accordance with their livestock production plan, natural pasture supply and suitability of establishing cultivated pastures, and the suitable areas for establishing cultivated pastures was selected based on natural and social limitations. Focusing on Xilin Gol Grassland, one of the typical pastoral areas in China, the characters of herdsmen livelihood behaviors and willingness for cultivated pasture construction were investigated by household survey, and the spatio-temporal variations of cultivated pastures and relevant economic-ecological consequences in future 30 years were simulated using the Agent-Based Model. The results showed that most suitable areas are distributed in the south of Xilin Gol Grassland near the agro-pastoral ecotone, where cultivated pastures are few now but should be newly established later. The number of cultivated pastures will gradually increase while the increasing speed will gradually descend in each county. With the expanding cultivated pastures, herdsmen's income will rise quickly in the first ten years then keep stable at 70000∼80000RMB nearly twice the original income, while the ecological pressure of grasslands will descend fast from >3 to 1 in the first eight years, then slowly from 1 to 0.5 and stay <0.5 after 2035. Such results proved that establishing cultivated pastures will really bring economic-ecological coordination on grasslands, which provided evidences for popularizing cultivated pastures to keep sustainable production and supply of livestock products and realize modern animal husbandry development.