Spatio-temporal dynamics and restoration mechanisms of plant-soil-microbe interactions following ecosystem engineering by plateau pikas in alpine meadows

Plant-soil-microbe interactions are essential for driving vegetation recovery, nutrient cycling, and ecosystem stabilization in degraded grasslands. However, the underlying mechanisms of these interactions during successional restoration following disturbance by semi-fossorial herbivores remain unclear. This study investigated bare patches formed by plateau pika ( Ochotona curzoniae ) disturbance, applying a space-for-time substitution to classify five successional stages: newly formed, short-term, long-term bare patches, vegetated patches in the disturbed areas, and vegetated surfaces in the undisturbed areas. The results demonstrated that vegetation recovery was characterized by increasing Cyperaceae, Gramineae, and forb biomass, and a compositional shift from pioneers ( Anaphalis lactea , Saussurea pulchra ) to late-successional perennials ( Elymus nutans , Leymus secalinus , Carex parvula ). Shannon , Simpson , richness, β diversity, and Cody index of plant communities varied significantly with succession, whereas Pielou's evenness remained stable. Microbial composition shifted from early copiotrophic and dung-associated taxa (e.g., Bacteroidota , Sphingomonadaceae , Peziza , Thelebolaceae ) to later-stage taxa (e.g., Reyranellales , Clavariaceae ). Soil saprotrophs and mycorrhizal fungi increased along the succession, while dung saprotrophs markedly declined. Although bacterial and fungal α diversity remained stable across stages, fungal β diversity differed significantly between long-term bare patches and vegetated surfaces, indicating greater sensitivity to successional change. Microbial community assembly was sequentially shaped by nutrient-related variables and pioneer vegetation, plant-mediated biotic filtering (e.g., Gramineae, Cyperaceae), and ultimately by soil physicochemical constraints (e.g., soil C: N ratio, pH). These findings indicate that fungal β diversity is a sensitive indicator of ecosystem recovery and underscore the critical role of plant-soil-microbe feedbacks in regulating successional dynamics. The study provides mechanistic insights to guide ecological restoration in degraded alpine meadows. • Vegetation recovery from pioneers to perennial graminoids and sedges. • Soil nitrogen exhibited the most pronounced changes during succession. • Fungal trophic shifted from dung-associated to soil saprotrophs and mycorrhizal groups. • Fungal β diversity varies across stages, bacterial diversity remains stable. • Microbiome shifts from disturbance-driven to plant- and soil-filtered processes.