## Results and Analysis
### Perceptions of the Grassland Ecological Changes of LGMs
#### 4.1.2 Perceptions of the LGMs on the Grass-Animal Interface  
According to the doughnut chart of the LGMs perception (Figure 5a), 31.25% of the LGMs believe that the grassland quality of Yanchi County has increased slightly after the GPP. After a further period without grazing, the grassland carrying capacity further improved. An increased number of LGMs perceived these changes of grassland quality as \"a little increase\" (68.75%) in the intermediate stage of GPP to \"greatly improved\" (62.5%) in the current stage (Figure 5a). Simultaneously, the LGMs perceived the selectivity of grassland yield as a \"significant improvement\" and increased from 37.5% in the early GPP to 43.75% in the mid-term and 56.25% in the current stage (Figure 5b). As a mandatory means, the GPP effectively inhibited herdsmen's over-grazing behavior, and slowed down the grassland desertification caused by the contradiction between forage yield and livestock demand for grass [8]. Thus, grassland ecology and vegetation were restored, and the carrying capacity was improved. It cannot be ignored that the grassland quality and forage yield declined in the current stage. The option selectivity of \"a little reduction\" of above index were 31.25% and 6.25%, respectively (Figure 5a,b). These conclusions were basically the same with the change rule of the grass-ground interface.  
According to the doughnut chart of the livestock amount (Figure 5c), 35.71% of the LGMs believe that the number of sheep of Yanchi County had increased significantly after the GPP. In the absence of awareness and expectation for the GPP, herdsmen as rational brokers have generally increased the number of sheep under the incentives of government that encouraged pen feeding and gave a subsidy for sheds. According to the [PERSON] et al. survey, the total amount of a sheep forage after 10 years of GPP increased by 60.7 kg compared with the early GPP period [19]. Due to the increase of the pen feeding cost, the herdsmen generally used night trespass grazing and obtained a semi-legalized status in the intermediate stage of GPP [20]. The health of herdsmen was greatly affected by the long-term night grazing, because this work was very intensive and risky. With the development of the county economy and the diversification of herdsmen livelihoods, 47.67% of the herdsmen adopted the shrinkage strategy of reducing the number of livestock [21]. About 50% of the retail breeding families cut back the livestock number [19], and the illegal grazing behavior decreased. According to the LGMs questionnaire, the selectivity of the regular ratio was 44%, occasionally 48%, and rarely 8% for the question \"In current stage of GPP, the occurrence frequency of trespass grazing of herdsmen\". The perception of the increase in the number of livestock dropped from 78.57% at the early stage, to 71.42% in the current stage of GPP.  
Figure 4: The local government managers (LGMs) perceptions on grass-ground interface in different grazing prohibition policy (GPP) periods. (**a**) indicate that the LGMs perception on grassland ecological. (**b**) indicate that the LGMs perception on grassland coverage. (**c**) indicate that the LGMs perception on species richness.