The relationship between biodiversity and ecosystem functioning has become a central issue in the fields of climate change and biodiversity conservation. The Qinghai-Tibet Plateau represents a globally typical ecologically fragile region， and with the intensification of global climate change， the structure and functioning of alpine meadow ecosystems are undergoing significant alterations. In this study， open-top chamber warming experiments were conducted to comprehensively assess plant species diversity and multiple ecosystem functions. Ecosystem multifunctionality was quantified using the averaging method to explore the relationships among simulated warming， species diversity， ecosystem functions， and multifunctionality. The results showed that warming suppressed the accumulation of aboveground and belowground biomass， while Margalef index， Simpson index， and Shannon-Weiner index decreased significantly （P<0.05）. Redundancy analysis indicated that ecosystem multifunctionality was significantly positively correlated with Margalef index， Shannon-Weiner index， and Simpson index （P<0.05）， with improvements in these indices accompanying enhancements in ecosystem functioning. Among these， species richness appeared to be a more critical influencing factor compared with species evenness and dominance. This study provides an important theoretical reference for understanding the responses and adaptive mechanisms of alpine meadow ecosystems under global climate change on the Qinghai-Tibet Plateau.

To clarify the molecular characteristics of the WRKY gene family in highly cold-resistant Pennisetum alopecuroides and their functions in cold stress response， in this study we conducted systematic identification， phylogenetic analysis and cold stress-related expression pattern analysis of the WRKY gene family via combined genome-wide and transcriptome analyses. The results showed that a total of 104 PaWRKY genes with complete WRKY domains were identified， which were unevenly distributed on nine chromosomes. All the encoded proteins were hydrophilic， and most of them had poor in vitro stability and were susceptible to degradation. Based on phylogenetic analysis， the taxa were divided into seven subtribes， and Subtribe IIc comprises the most members， and ten core conserved motifs were predicted in total. Extensive homologous collinearity was found between this gene family and Oryza sativa subsp. japonica. The promoter regions of PaWRKY genes were enriched with numerous cis-acting elements responsive to abiotic stresses and phytohormones. Transcriptome data revealed that eight PaWRKY genes were differentially expressed under cold stress， including four upregulated and four downregulated genes， all of which harbored MeJA-responsive elements. This study clarified the molecular and evolutionary characteristics of the WRKY gene family in Pennisetum alopecuroides and screened out key cold stress-responsive genes， which laid a theoretical foundation for cold-tolerant molecular breeding of Pennisetum alopecuroides and evolutionary research of the WRKY gene family in Panicoideae.

This study aimed to evaluate the effect of Lactobacillus plantarum （LP） addition on the silage quality of forage oat （Avena sativa） varieties grown in different regions， thereby providing a theoretical basis for the promotion of new forage oat varieties and the optimization of silage processing techniques. Three oat varieties， ‘Zhongxuyan No.1’ （a new strain）， ‘Qinghai Sweet Oat’， and ‘Qingyin No.2’， were grown in Qinghai and Ningxia. After harvesting at the milk stage， the oats were ensiled under identical conditions with either distilled water （control） or LP treatment for 60 days， after which the silage samples were subjected to sensory evaluation as well as nutritional and fermentation quality analyses. The results showed that LP addition significantly improved the sensory scores and V-Score grades. Nutritional analysis revealed that the crude protein （CP） and ether extract （EE） contents of ‘Zhongxuyan No.1’ silage were significantly higher than those of the other varieties （P<0.01）. Fermentation analysis demonstrated that region significantly affected pH （potential of hydrogen）， lactic acid （LA）， butyric acid （BA）， and the NH₃-N∶TN （ammonia nitrogen∶total nitrogen） ratio in oat silage （P<0.01）， and the pH and BA contents of ‘Zhongxuyan No.1’ were significantly lower than those of the other varieties （P<0.01）. A comprehensive comparison of treatments indicated that LP addition was more beneficial for improving silage fermentation quality. Among the three varieties tested， ‘Zhongxuyan No.1’ performed well in both regions and was identified as the most suitable variety for silage.

To elucidate the physiological basis underlying provenance-dependent variation in seed germination of Acanthopanax senticosus， seeds collected from four locations in Heilongjiang Province， China-Acheng District （AC）， Mulan County （ML）， Gaoleng Town of Fangzheng County （GL）， and Tongbei County （TB）-were examined for phenotypic traits and germination performance， together with endogenous hormone dynamics during sand stratification and metabolomic profiles. The results showed that seeds from GL exhibited significantly higher germination rates and greater hundred-seed weight than those from the other provenances. In terms of hormonal regulation， GL seeds displayed the highest brassinosteroid （BR） content and the lowest abscisic acid （ABA） content at the late stage of stratification. Metabolomic analysis further indicated that prior to stratification， GL seeds were characterized by an accumulation of carbohydrates accompanied by reduced levels of stress-associated metabolites， whereas after stratification they preferentially enriched metabolites related to energy supply and biosynthetic processes. Weighted gene co-expression network analysis （WGCNA） revealed that the MEturquoise and MEred modules were positively associated with hundred-seed weight before stratification， while the MEyellow module was correlated positively with germination rate after stratification， highlighting key metabolite regulators. Collectively， these findings suggested that the superior germination potential of GL seeds was attributable to favorable seed traits， a more balanced hormonal status， and metabolically efficient reprogramming. This study provides a theoretical foundation for optimizing sand stratification practices and improving artificial propagation efficiency.

In order to overcome the bottleneck of low seed yield during its propagation process， this study investigated the effects of foliar application of phosphorus （P）， potassium （K）， and zinc （Zn） on the seed yield of Kengyilia thoroldiana. Four gradient levels of potassium dihydrogen phosphate （KH₂PO₄）， including 30 kg·hm^-2 （A₁）， 60 kg·hm^-2 （A₂）， 90 kg·hm^-2 （A₃）， and 120 kg·hm^-2 （A₄）， were combined with a fixed amount of zinc sulfate （ZnSO₄） （6.25 kg·hm^-2） for foliar co-application. Key agronomic traits， photosynthetic characteristics， seed yield， and nutritional quality were systematically evaluated. A membership function analysis was employed to conduct a comprehensive assessment of all treatments， enabling the identification of the optimal fertilization combination. Results showed that compared with control （CK）， the A₃ treatment significantly increased the grass height， reproductive stem height， and flag leaf area of Kengyilia thoroldiana by 44.45%， 45.85%， and 45.15%， respectively. In terms of photosynthetic characteristics， the net photosynthetic rate and SPAD value of the flag leaf under the A₃ treatment were 30.72% and 54.10% higher than those under CK， respectively. Regarding seed yield， the A₃ treatment produced the highest yield， 593.23 kg·hm^-2， which was 40.68% greater than CK. Principal component analysis （PCA） and membership function analysis revealed that the A₃ treatment had the highest comprehensive evaluation D value （0.93）， followed by the A₂ treatment. The CK treatment exhibited the poorest performance in all evaluated parameters. In conclusion， foliar applications of KH₂PO₄ and ZnSO₄ enhanced the growth and development of Kengyilia thoroldiana， improved photosynthetic performance， and increased seed yield. The combined foliar application of 90 kg·hm^-2 KH₂PO₄+6.25 kg·hm^-2 ZnSO₄ demonstrated the most effective outcome， providing a scientific basis for optimizing seed production in Kengyilia thoroldiana.

This study aimed to elucidate the effects of varying grazing intensities on soil active organic carbon fractions and their environmental driving mechanisms in the typical steppe of Xilingol League， which could provide empirical support for carbon management strategies in grassland ecosystems. Three grazing treatments—no grazing （CK）， moderate grazing （MG）， and heavy grazing （HG）—were established in the experimental area using a completely randomized block design with five replicates per treatment. Soil physicochemical properties， soil organic carbon （SOC）， and its active fractions were quantified and analyzed. Compared to CK， MG significantly decreased the contents of particulate organic carbon （POC） and microbial biomass carbon （MBC）， but significantly increased the easily oxidizable organic carbon （EOC） content. The HG treatment significantly reduced the contents of POC and dissolved organic carbon （DOC）. Furthermore， POC and MBC contents under MG were significantly higher than those under HG. SOC exhibited a highly significant positive correlation with all its active fractions （P<0.05）. Soil water content （SWC） and total nitrogen （TN） were identified as the key factors influencing SOC and its fractions. Overall， grazing reduced the contents of SOC and its active fractions in the typical steppe. Therefore， avoiding heavy grazing is recommended. Incorporating soil moisture regulation and moderate nitrogen supplementation during pasture utilization can enhance soil carbon sequestration， thereby maintaining soil quality and carbon pool functionality.

Arbuscular mycorrhizal fungi （AMF） are key symbiotic microorganisms that support nutrient acquisition by grassland plants and contribute to soil structure maintenance. This review synthesizes current progress on how different forms of carbon input， nitrogen addition， and their interactions influence AMF in grassland ecosystems， focusing on colonization， hyphal growth， community composition， and symbiotic network structure. Elevated atmospheric CO₂ mainly promotes AMF hyphal growth and biomass accumulation by increasing belowground carbon allocation in plants. Biochar application and organic fertilizer addition improve soil physical properties and nutrient retention， thereby facilitating AMF colonization and community recovery. In contrast， the effects of soluble organic carbon inputs are moderated by plant functional group identity and nitrogen-phosphorus availability. Long‑term or high‑intensity nitrogen addition generally suppresses AMF， a response closely associated with soil acidification， reduced carbon allocation to mycorrhizae， and reorganization of AMF communities. The interactive effects of carbon inputs and nitrogen addition are constrained by carbon source characteristics， nitrogen legacy effects， and the availability of soil nutrients. Future research should increase the comparability of carbon input studies， clarify the combined regulatory roles of carbon source， nitrogen addition intensity and duration on AMF responses， and provide theoretical support for soil nutrient management and degraded grassland restoration.

Phytochrome A （phyA） is a key receptor that enables plants to perceive far-red light signals and regulates their growth， development， and stress responses. To investigate the function of the MsphyA gene and its molecular mechanism in response to abiotic stress in alfalfa （Medicago sativa L.）， this study conducted a bioinformatic analysis of the cloned MsphyA gene and detected its expression patterns under various abiotic stresses using qRT-PCR. Bioinformatic analysis revealed that the MsphyA gene has a CDS length of 3375 bp， encoding 1124 amino acids， and possesses typical PAS， GAF， and PHY motifs characteristic of the PHY family. Protein analysis indicated that MsphyA has a relative molecular mass of 124.3 kDa and a theoretical isoelectric point of 6.1. It is classified as an unstable， hydrophilic， non-secretory protein without a signal peptide and lacks transmembrane domains. Subcellular localization prediction suggested that MsphyA is localized to the nucleus. Phylogenetic analysis showed that MsphyA is most closely related to MtphyA from M. truncatula. qRT-PCR results demonstrated that salt， drought， acid， high-temperature， and low-temperature stresses all induced MsphyA expression. These findings indicate that MsphyA is widely involved in the abiotic stress responses in alfalfa. This study provides a foundation for further exploration of the MsphyA gene’s function.

To investigate the salt tolerance of wild Annual bluegrass （Poa annua L.） germplasm resources in Northwest China， ten wild populations collected from Lanzhou （LZ）， Jiuquan （JQ）， Maiji （MJ）， Zhangye （ZY）， Huangzhong （HZ）， Wuwei （WW）， Baiyin （BY）， Jinchang （JC）， Xihe （XH）， and Zhouqu （ZQ） were used as experimental materials. A pot experiment was conducted to investigate the effects of different soil salinity levels （0.2%， 0.5%， 0.8%， and 1.1%） on plant growth， cell membrane system， and osmotic adjustment system of P. annua， and to comprehensively evaluate their salt tolerance. The results showed that with increasing salt stress， plant height， leaf length， leaf width， and potassium and calcium ion contents of the ten germplasms decreased gradually， whereas relative electrical conductivity， malondialdehyde content， free proline content， soluble sugar content， and sodium ion content increased. The overall salt tolerance of the germplasms was ranked as LZ>JQ>BY>JC>ZY>WW>HZ>ZQ>XH>MJ. At a soil salinity level of 0.8%， theLZ and JQ exhibited lower salt injury than the others， indicating stronger salt tolerance， and suggesting their potential for cultivation in saline soils of Northwest China.

Ethylene response factors （ERFs） are key regulatory proteins involved in plant responses to abiotic stresses. In this study， based on the genome data of Pennisetum purpureum， 53 members of the PpERF gene family were identified. The encoded proteins ranged from 191 to 1145 amino acids in length， with predicted isoelectric points ranging from 4.75 to 11.79 and molecular weights ranging from 20 536.11 to 124 866.3 Da. Among these genes， three were not mapped to the chromosomes， whereas the remaining genes were unevenly distributed across eight chromosomes. Phylogenetic analysis classified the PpERF genes into three evolutionary clades. Most PpERF proteins contained highly conserved Motifs 1， 2， and 4， and multiple stress-responsive cis-acting elements were identified in their promoter regions. Expression analysis showed that 11 PpERF genes exhibited spatiotemporal expression specificity under low-temperature stress， among which PpERF17， PpERF21， and PpERF32 were significantly upregulated after 24 h of cold treatment. Transient overexpression assays in tobacco further demonstrated that these three genes significantly enhanced plant tolerance to low-temperature stress. This study provides a theoretical basis for elucidating the molecular mechanisms underlying low-temperature responses in Pennisetum purpureum and offers potential candidate genes for the breeding of cold-tolerant forage grasses.