基于meta分析的放牧压力对内蒙古高原草地生态系统的影响

放牧是最主要的草地利用模式，直接或间接地影响草地物质循环和能量流动，放牧强度对草地的健康状况和演替方向起决定作用。本文基于40篇内蒙古草原放牧相关文献数据，通过meta分析探讨温带草原对放牧强度的响应特征。结果表明，与未放牧草地相比，轻度放牧草地对群落植物地上、地下生物量和土壤全氮和全磷含量无显著影响，而土壤有机碳、微生物生物量碳、细菌和真菌数量分别显著上升3.60%、7.80%、11.40%和10.83%（P<0.05）；中度放牧下群落植物地下生物量和土壤微生物数量无显著变化，而地上生物量和土壤有机碳、全氮、全磷和微生物生物量氮含量分别显著降低21.62%、4.44%、2.15%、8.35%和6.76%（P<0.05）；重度放牧下群落植物地上和地下生物量，土壤有机碳、全氮、全磷、微生物生物量碳含量，细菌和放线菌数量分别显著下降39.72%、16.30%、7.62%、6.46%、8.03%、8.76%、12.92%和18.27%（P<0.05）。以上结果表明轻度放牧有利于土壤肥力和草地生产力的保持和提升，而当放牧干扰超出一定的限度时，草地各项功能均显著下降而发生退化。本研究可为内蒙古温带草原的合理利用和适应性管理提供理论基础。

Effects of grazing on temperate grassland ecosystem based on a meta-analysis

The temperate semi-arid grassland in Inner Mongolia is primarily used for grazing, which directly and indirectly affects material circulation and energy flow. Grazing intensity plays a decisive role in the health status and direction of grassland succession. Data from 40 studies about Inner Mongolia grassland grazing intensity were analyzed via a meta-analysis. The results showed that compared to the non-grazing grassland, light grazing did not affect the above- and below-ground biomass, soil total nitrogen, and total phosphorus, but significantly increased (P<0.05) the soil organic carbon (3.60%), microbial carbon (7.80%), bacteria (11.40%), and fungi (10.83%). Moderate grazing did not affect the below-ground biomass and the number of microorganisms, but significantly reduced (P<0.05) the above-ground biomass (21.62%), soil organic carbon (4.44%), total nitrogen (2.15%), total phosphorus (8.35%), and microbial biomass nitrogen (6.76%). Heavy grazing significantly decreased (P<0.05) the above- and below-ground biomass (39.72% and 16.30%, respectively), soil organic carbon (7.62%), total nitrogen (6.46%), total phosphorus (8.03%), microbial biomass carbon (8.76%), bacteria (12.92%), and actinomyces (18.27%). These findings suggest that light grazing benefits soil fertility and grassland productivity; however, the grassland ecosystem''s functional capacity weakens once the grazing intensity exceeds a certain threshold. This information is useful for adapting management strategies to prevent grassland degradation.