Understanding the roles of core bacterial taxa in forage production is crucial for developing sustainable fertilization practices that enhance the soil bacteria and forage yield. This study aims to investigate the impact of different fertilization regimes on soil bacterial community structure and function, with a particular focus on the role of core bacterial taxa in contributing to soil nutrient content and enhancing forage yield. Field experiments and high-throughput sequencing techniques were used to analyze the soil bacterial community structure and function under various fertilization regimes, including six treatments, control with no amendment (CK), double the standard rate of organic manure (T01), the standard rate of organic manure with nitrogen input equal to T04 (T02), half the standard rate of inorganic fertilizer plus half the standard rate of organic manure (T03), the standard rate of inorganic fertilizer reflecting local practice (T04), and double the standard rate of inorganic fertilizer (T05). The results demonstrated that organic manure treatments, particularly T01, significantly increased the forage yield and the diversity of core bacterial taxa. Core taxa from the Actinomycetota, Alphaproteobacteria, and Gammaproteobacteria classes were crucial in enhancing the soil nutrient content, directly correlating with forage yield. Fertilization significantly influenced functions relating to carbon and nitrogen cycling, with core taxa playing central roles. The diversity of core microbiota and soil nutrient levels were key determinants of forage yield variations across treatments. These findings underscore the critical role of core bacterial taxa in agroecosystem productivity and advocate for their consideration in fertilization strategies to optimize forage yield, supporting the shift towards sustainable agricultural practices.

Alpine grasslands are a critical component of the Qinghai–Tibet Plateau ecosystem, but their soil seed bank (SSB) patterns and driving mechanisms remain unclear under the influence of climate change and human activities. This study analyzed grazing exclusion (via fencing) and grazing effects using 12 sites in the alpine steppe (AS) and alpine desert steppe (AD) in northern Tibet to analyze the effects of fencing and grazing management, as well as hydrothermal and soil factors, on the SSB density and diversity. Linear regression models were applied to explore the relationships between the SSB density and environmental factors, while comparisons of the management modes revealed the potential impacts of fencing. The results show that fencing significantly increased the SSB density and diversity, especially in the AS, while grazing negatively impacted the SSB density and the Pielou evenness index. Hydrothermal factors strongly influenced the SSB in the AS, with the density positively correlated with precipitation and negatively with temperature, while responses in the AD were weak. Soil factors, such as the available phosphorus (SAP) and available potassium (SAK), were key to SSB formation in the AD, whereas ammonium nitrogen (NH4_N) and the pH were critical in the AS. Fencing optimized the hydrothermal conditions and nutrient availability, promoting SSB recovery, though its effects varied between the grassland types. This study provides scientific insights for alpine grassland restoration and sustainable management.

Background and Aims The degradation of alpine grasslands on the Qinghai-Tibet Plateau has been alleviated in some regions, while varying degrees of degradation persist in others. Soil seed banks (SSBs), reflecting the past, present, and future potential of plant communities, are critical for restoration. This study assessed fencing, a nature-based solution (NbS), addressing regional biases and limited cross-regional synthesis in prior research. Methods Paired plots of free grazing and fenced grazing were established through field sampling. Community and SSB characteristics were compared between fenced and grazed areas using vegetation and seed bank surveys, seed germination experiments, and statistical analyses. Structural equation modeling (SEM) was employed to identify regulatory pathways influencing seed density under both management regimes. Results Fencing increased seed density (346–20,961 seeds/m²) compared to grazed areas (346–14,378 seeds/m², p<0.05). The Sørensen similarity index indicated altered community structure and retrogressive succession (fenced: 0.803; grazed: 0.766). Fencing raised the importance value (IV) of Poaceae by 8.70% but reduced non-grass species richness and IV by 8.13%. SEM explained 95.04% (fenced) and 97.30% (grazed) of seed density variation, with fencing weakening seed density response to precipitation. Conclusions Fencing significantly affects SSBs by altering seed density, community structure, composition, and diversity. These changes reduce the sensitivity of SSBs to precipitation and may contribute to retrogressive succession in alpine grasslands. This study provides theoretical support for utilizing SSBs as a target for NbS to restore degraded alpine grasslands on the Qinghai-Tibet Plateau.