Three different herbivore grazing assemblages, namely, yak grazing (YG), Tibetan sheep grazing (SG) and yak and Tibetan sheep co-grazing (MG), are practiced in alpine meadows on the Qinghai-Tibetan Plateau (QTP), but the effects of the different herbivore assemblages on soil microbes are relatively unknown. The microbial community plays an important role in the functional stability of alpine grassland ecosystems. Therefore, it is important to understand how the microbial community structure of grassland ecosystems changes under different herbivore grazing assemblages to ensure their sustainable development. To fill this gap, a field study was carried out to investigate the effects of YG, SG, and MG on plant communities, soil physico-chemical properties and microbial communities under moderate grazing intensity in alpine meadows. Grazing increased the β-diversity of the bacteria community and decreased the β-diversity of the fungal community. The herbivore assemblage affected the microbial community diversity, but not the plant community diversity. Total phosphorus, soil bulk density, root biomass, and plant α-diversity were correlated with both the bacterial and fungal community composition, available phosphorus and soil moisture were correlated only with the bacterial community composition, while available potassium and above-ground net primary production (ANPP) were correlated only with the fungal community composition. Soil available nitrogen, soil available phosphorus and soil bulk density were highest in SG, while ANPP was highest in MG. It was concluded that MG can improve ANPP and stabilize the soil microbial community, suggesting that MG is an effective method for sustainable use and conservation of alpine meadows on the QTP.

Chinese traditional herbs are used widely as feed supplements to improve the immune response and antioxidant capacity of livestock. Twenty early-weaned 4-month-old yak calves (72.3 ± 3.65 kg) were divided randomly into four groups (n = 5 per group); three groups were provided with supplementary 80 mL/kg DMI of the root water extracts of either Angelica sinensis, Codonopsis pilosula or Glycyrrhiza uralensis, and one group (control) was not provided with a supplement. Compared to control calves, calves consuming the three herbal extracts increased serum concentrations of albumin (ALB) and glutathione peroxidase (GSH-Px), but decreased serum concentrations of free fatty acids (FFAs) and malondialdehyde (MDA) (p < 0.05). Calves consuming A. sinensis decreased (p < 0.05) serum concentration of total cholesterol (TC), and increased (p < 0.05) serum concentration of total proteins (TP). Serum FFA concentrations increased (p = 0.004) linearly with time in the control group, but not in the groups consuming herbs. Serum metabolomic data demonstrated that A. sinensis and C. pilosula regulate mainly amino acid metabolism, while G. uralensis regulates mainly carbon and amino acid metabolism. It was concluded that the three herbal root extracts, as dietary supplements, improved energy and nitrogen metabolism, and enhanced the antioxidant capacity of yak calves.

Establishing perennial cultivated grasslands on the Qinghai-Tibet Plateau helps address the seasonal imbalance of forage resources and supports the restoration of degraded grasslands. The most common planting patterns—monocropping and mixed cropping—are well-studied in terms of vegetation structure, productivity, and soil nutrients. Despite their significance, the influence of prolonged planting practices on underground soil microbial communities and metabolites has often been neglected. In this study, two characteristic plants, Festuca sinensis ‘Qinghai’ and Poa pratensis ‘Qinghai’, from the area around Qinghai Lake were selected as the experimental subjects by employing 16 S and ITS sequencing methods in conjunction with non-targeted metabolomics analysis. The effects of planting patterns (monocropping and mixed cropping) on rhizosphere soil characteristics, metabolites and microbial community structure were examined. The results showed that compared with monocropping, mixed cropping significantly increased the contents of soil nutrients and key metabolites. In addition, it had a greater impact on fungal diversity than bacterial diversity, particularly in terms of β-diversity. While microbial α-diversity and dominant phyla remained stable, soil fungi were more responsive to changes in soil properties and metabolites. These results show that the new niche differentiation between different species in mixed grassland stimulates the secretion of trehalose and valine, which further affects the fungal community structure and enhances the soil nutrients and ecological functions of degraded grasslands. These findings will guide the restoration of degraded grasslands around Qinghai Lake and the selection of planting strategies to improve local sustainable grassland productivity.

The rhizosphere, as the primary site of plant–soil –microbe interactions, plays an important role in plant productivity. The influence of plant species on rhizosphere soil properties and how this influence shapes the productivity of grassland ecosystems remains poorly understood. Therefore, this study analyzed the changes in bacterial community structure and metabolites in the rhizosphere soil of perennial cultivated grassland. The aim was to elucidate the pathways and underlying mechanisms by which soil physicochemical properties, bacterial community structure, and rhizosphere metabolites influence productivity. Taking perennial monocropping grasslands established with three common grass species from the Qinghai –Tibet Plateau as the research objects, a comprehensive study was conducted using replicated field trials. Rhizosphere soil samples were collected from Elymus breviaristatus, Festuca sinensis, and Poa pratensis. The results indicated significant differences in productivity, soil physicochemical properties, bacterial diversity, and community structure among the monocropping grasslands. Among them, ANPP (589.17 g·m⁻²), root biomass (3601.67 g·m⁻²), moisture (18.15%) and Verrucomicrobiota (3.60%) of Elymus breviaristatus are higher than those of Festuca sinensis and Poa pratensis, while the relative abundance of Firmicutes (0.82%) is lower than that of Festuca sinensis and Poa pratensis. The topological characteristics of soil bacterial networks varied among the different grass species. The abundances of metabolites consisting of phenylalanine, proline, raffinose, maltotriose, uridine, and 2‐methylbenzaldehyde differed among different treatments. Pathway analysis highlighted the upregulation of ABC transporters and pyrimidine metabolism pathways in Elymus breviaristatus compared to Festuca sinensis and Poa pratensis. Moreover, Elymus breviaristatus secreted more uridine, which prevents the recruitment of pathogenic bacteria (such as Firmicutes) and promotes the recruitment of Verrucomicrobiota, thus improving grassland productivity. These findings show that the productivity of perennial monocropping grasslands around Qinghai Lake is the result of the interaction among rhizosphere soil nutrients, metabolites, and microorganisms. From the ecological point of view, Elymus breviaristatus is more conducive to the improvement of forage yield and the restoration of degraded grassland.

Soil ecosystems host diverse microbial communities, which are influenced by various environmental factors, soil properties, vegetation characteristics, and anthropogenic activities, such as livestock grazing. Grazing serves as a critical management practice in the alpine grasslands of the Qinghai‐Tibet Plateau, affecting soil microbial communities and their functions through processes such as forage consumption, trampling, and the deposition of feces and urine. In this study, we utilized the scientific and technological platform “Alpine Grassland‐Livestock Adaptive Management Technology Platform” in Qinghai Province to examine the effects of grazing intensity on soil microbial communities and functions. Experimental treatments included different grazing intensities (light grazing, moderate grazing, and heavy grazing), along with a no‐grazing control. Metagenomic sequencing technology was employed to investigate the impact of these grazing intensities on the microbial community composition and functional attributes in alpine grasslands. The results indicated that: (1) Actinobacteria, Proteobacteria, and Chloroflexi were the dominant bacterial communities in the soil, while Ascomycota, Mucoromycota, and Basidiomycota represented the primary fungal communities. (2) Grazing had a greater impact on soil fungal communities than on bacterial communities, altering the Shannon diversity index and Simpson index of soil fungal communities. (3) Soil pH and soil moisture were important factors influencing changes in soil microbial communities. (4) Functional analysis focusing on the “nitrogen metabolism” pathway indicated that under light grazing conditions, the relative abundance of multiple functional genes, particularly those involved in denitrification, decreased.