Short‐Term Management Interventions Alter the Correlation Between Rhizosphere Microbial Communities and Ecosystem Multifunctionality in Alpine Cultivated Grasslands

ABSTRACT

Management interventions restore degraded alpine ecosystems; however, their short‐term effects on ecosystem multifunctionality (EMF) and rhizosphere microbiomes remain elusive. Here, we examined how organic fertilisation, plant growth‐promoting rhizobacteria, and arbuscular mycorrhizal fungal (AMF) inoculation (collectively, management interventions) affect EMF and multi‐kingdom microbiomes in a Qinghai‐Tibetan Plateau cultivated grassland. The three management interventions significantly increased plant‐related functions; however, organic fertiliser use reduced nitrogen‐related functioning, leaving carbon and phosphorus functions unchanged, indicating an asynchronous functional response. Rhizosphere bacterial composition remained stable, whereas fungal alpha diversity declined and both fungal and AMF community compositions shifted significantly. Furthermore, management interventions altered co‐occurrence network topology, creating a less hub‐dependent architecture and reducing negative cross‐kingdom associations. Importantly, total EMF correlated negatively with AMF richness and negative bacteria‐fungi links, reflecting a transition towards functional specialisation and reduced inter‐kingdom metabolic friction. Our findings suggest that short‐term performance gains in cultivated grasslands are primarily mediated by microbial network restructuring and trait‐based filtering rather than generalised diversity accumulation, highlighting the importance of monitoring microbial network integrity alongside macro‐biomass yields to ensure the long‐term sustainability of alpine cultivated grasslands.