Enclosure Enhances Grassland Plant Diversity and Community Stability More Effectively Than Grazing and Mowing by Strengthening Species Turnover Regulation and Soil Process Driving

Shi Mengyuan¹Tianqi Yu¹Chen Sisi¹Zhang Chu¹Xiaoping XIN¹He Senya¹Liu Fanglin^1,2Ji Li¹Li Ying¹Gao Xiaotian¹Yan Ruirui^1*

• ¹Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
• ²Xinjiang Agricultural University, Urumqi, China

Grassland ecosystems are profoundly influenced by land management practices, yet the long-term mechanisms linking plant diversity and community stability remain unclear. In this study, we conducted three-year observational study to assess how enclosure, grazing, and mowing affect plant community dynamics through species turnover, niche overlap, and environmental drivers in the Hulunbuir temperate meadow steppe of Inner Mongolia. Using 198 permanent quadrats monitored over three consecutive growing seasons, we quantified α-, β-, and γ-diversity and assessed stability via biomass variability. Enclosure was associated with higher species richness and lower biomass variability, suggesting enhanced community stability under reduced disturbance, whereas grazing was associated with lower species richness and greater temporal and spatial variability in community structure, potentially linked to intensified species turnover and soil compaction. Mowing generally showed intermediate patterns, reflecting moderate alteration of competitive dynamics and community composition. Our analyses further revealed that soil physical properties and nutrient availability—particularly soil bulk density(SBD), total nitrogen (TN), and organic carbon (OC)—were key environmental factors associated with variation in plant diversity and stability across management regimes. Structural equation modelling based on observational data indicated that these environmental factors may influence diversity and stability both directly and indirectly, with pathways differing among management types. Our findings indicate that grassland management practices modulate diversity–stability relationships in a management-dependent manner, likely through their effects on species turnover, niche structure, and soil–plant feedbacks. These results highlight the importance of context-specific management strategies for sustaining grassland stability under ongoing environmental change.