Analysis of the temporal and spatial evolution of the grass-animal balance in Winsor County from 2000 to 2022

Accurate assessment of the grass-animal balance in grassland ecosystems is key to maintaining their sustainability and scientifically managing livestock production and activities. Therefore, in this study, we constructed a multifactorial grassland grass production model based on random forest to analyze the spatial and temporal changes of seasonal pasture grass production and theoretical livestock carrying capacity in Wensu County from 2000 to 2022. Moreover, we discussed the grass-animal balance status in the county. The accuracy parameters of the grass production inversion model were R² = 0.46, RMSE = 389.94 kg·hm⁻², and MAE = 297.89 kg·hm⁻². Grass production per unit area showed a decreasing distribution from the central and southwestern part of the county to the two ends of the county, whereas the theoretical livestock carrying capacity showed a high distribution in the north and a low distribution in the south. The grass production per unit area, theoretical livestock carrying capacity, and carrying capacity of summer pastures were all high, and the total grass production of the four-season pastures was high. In 2000, the county’s grass production and theoretical livestock capacity reached the highest at 522.17 × 10³ t and 36.18 ten thousand SU, with an overall decreasing trend during the 23-year period. In contrast, the actual livestock carrying capacity was a maximum of 127.79 ten thousand SU in 2022. Overall, the average grass-animal balance index value for the 23 years was 195.27%, indicating an overloading phenomenon. Therefore, this study provides a theoretical foundation and basis for ecological protection and management in Wensu County.