Heat shock transcription factor （HSF）， widely found in eukaryotes， are one of the most crucial transcriptional factors families in the plant resistance to heat stress. HSF has highly conserved DNA-binding domain （DBD）， which is involved in complex stress signal transduction and response networks. HSF， as a terminal component of the signal transduction chain， mediated the expression of target genes under abiotic stress. In response to stress， HSF is phosphorylated and ubiquitinated by upstream protein kinases or binds to heat shock elements （HSEs） through ABA signaling pathway to regulate the expression of downstream genes such as heat shock proteins （HSPs）， thereby improving plant stress resistance. In this study， the discovery， structure， classification， regulatory mechanism of HSF and its role in plant response to abiotic stress （extreme temperature， drought， high salinity， heavy metal， et al.） were reviewed， and the future research direction was expected to provide theoretical basis and gene resources for the genetic improvement of crop and forage stress resistance.

Nutrient enrichment is a key driver of plant diversity loss in grassland ecosystems. However， the specific pathways and mechanisms underlying species diversity reduction under different nutrient additions influence remain insufficiently understood. This study investigated the effects of nitrogen （N）， phosphorus （P）， and combined nitrogen and phosphorus （N+P） additions on alpine meadows located on the eastern edge of the Tibetan Plateau， using the natural community as a control. The main objective was to examine changes in species richness， biomass， and light transmission， and to elucidate the direct and indirect mechanisms contributing to species richness decline under these experimental treatments. The results showed as follows：（1） N was identified as the primary limiting nutrient for aboveground biomass. Both N and N+P additions significantly increased aboveground biomass （P<0.05）， primarily due to an increase in the biomass of grasses； （2） N and N+P additions significantly reduced species richness （P<0.05）， whereas P addition alone had no significant effect； （3） The mechanisms underlying the reduction in species richness under N and N+P treatments were consistent and involved both direct effects of nitrogen and indirect effects via increased aboveground biomass， which in turn reduced light availability.

Shrub encroachment， which significantly alters structure and function of grassland ecosystems， is a critical ecological issue in China. To obtain a comprehensive and quantitative understanding of the research trends on shrub encroachment research in China， this study conducted a bibliometric analysis using CiteSpace and a meta-analysis based on published literatures on shrub encroachment in China since 1970s. Research on shrub encroachment in China had developed rapidly in recent years， with a primary focus on the drivers of shrub encroachment and its impacts on soil， vegetation， and biodiversity. Studies on shrub encroachment in China had been predominantly conducted in drylands and alpine regions. Major drivers of shrub encroachment included grazing management， climate change， habitat characteristics， and fire. Shrub encroachment was found to have a negative impact on soil quality but a positive effect on community composition， as well as the structure of vegetation and microbial communities in China. The primary management techniques for shrub encroachment included grazing exclusion， grazing management， physical removal， and prescribed burning. This study provides scientific insight into the drivers， impact， and future management strategies for shrub encroachment in Chinese grassland. In the future， it is necessary to strengthen large-scale dynamic assessments of shrub encroachment across diverse grassland types， and integrate remote sensing technology to enhance the scientificity and effectiveness of monitoring and management of encroached landscape in China.

In this study， alfalfa （Medicago sativa cv. Zhongmu No.1） was used as experimental material under mixed saline-alkali stress at concentrations of 0， 40， and 80 mmol/L （NaCl， Na2SO4， Na2CO3 and NaHCO3 molar ratios of 1∶1∶1∶1， pH 9.3）. The growth indexes， physiological indexes and the expression levels of key genes of the seedlings were measured， which provided a theoretical basis for revealing the mechanism of response to mixed saline-alkali stress. The results showed that the plant height， photosynthetic rate， effective quantum yield of PSⅡ photochemistry and the maximum quantum efficiency of PSⅡ photochemistry （Fv/Fm） in ‘Zhongmu No.1’ alfalfa seedlings were significantly inhibited with the intensification of mixed saline-alkali stress （P<0.05）. The accumulation of hydrogen peroxide， superoxide anion， and malondialdehyde gradually increased， while the activity of peroxidase， proline， and soluble sugar content all significantly increased （P<0.05）. Under 80 mmol/L mixed saline-alkali stress， the expression levels of Na+ transporter encoding genes MsSOS1， MsNHX1， and MsHKT1 were significantly induced （P<0.05）. In summary， ‘Zhongmu No.1’ alfalfa may mainly respond to mixed saline-alkali stress through the following pathways： （1） high expression of Na+ transporter genes such as MsSOS1， MsNHX1， and MsHKT1， promoting Na+ efflux， vacuolar segregation and transfer， and avoiding ion toxicity to plants caused by excessive accumulation of Na+； （2） enhance antioxidase activity and alleviate oxidative damage caused by high pH value.

Grazing is a primary utilization of grassland ecosystems， where livestock behaviors， specifically feeding， trampling， and excrement deposition， directly or indirectly alter soil physicochemical and biological properties. These alternations， in turn， differentially affect biogeochemical processes within the grassland ecosystem. However， the mechanisms by which these behaviors influence soil greenhouse gas （GHG） emissions remain poorly understood. To address this knowledge gap， this study systematically explored the emission mechanism and key influencing factors of carbon dioxide （CO₂）， methane （CH₄）， and nitrous oxide （N₂O） in grassland soil by analyzing the interactions between major grazing behaviors and soil environmental conditions. The results showed that feeding behavior can alter vegetation biomass and regulate vegetation community structure， thereby modifying exogenous carbon inputs to influencing soil CO₂ emissions. Trampling behavior impacts soil physical structure and microenvironmental conditions， which in turn affect soil aeration and microbial activity， leading to variable effects on soil respiration and associated CH₄ and CO₂ emissions. These effects are closely dependent on grassland type and trampling intensity. In contrast， dung and urine deposition increase nitrogen input to the soil and enhance N₂O emissions， primarily by altering soil chemical properties and microbial dynamics. The characteristics of the excreta， grassland type， and environmental conditions all play important roles in regulating nutrient availability and GHG emission in pastoral systems. These findings elucidate the distinct processes and potential mechanisms through which livestock behaviors affect soil GHG emissions in grassland and provide a theoretical basis for optimizing grazing management to mitigate emissions in pastoral ecosystems.

In order to investigate the root-specific genes regulating root growth of alfalfa （Medicago sativa），transcriptome sequencing was performed to analyze differentially expressed genes （DEGs） and their functions between the aerial parts （stems and leaves） and root system of alfalfa cultivar Zhongmu No. 1. The results showed that compared to aerial parts，a total of 15258 DEGs were identified in root system，including 5095 up-regulated and 10163 down-regulated. The GO functional annotation demonstrated significant enrichment of these DEGs in cellular process，metabolic regulation，and biocatalytic activities. KEGG pathway enrichment analysis showed significant enrichment of these DEGs in pathways related to porphyrins and chlorophyll metabolism，photosynthesis-antenna protein synthesis，and carbon fixation in photosynthetic organisms. Six candidate up-regulated genes exhibiting significant differential expression were selected for real-time quantitative PCR validation. The results indicated high concordance between their expression patterns and transcriptome sequencing data.

Phytolith-occluded organic carbon （PhytOC）， which is a part of the organic carbon encapsulated during the silicification process in grassland plants， constitutes an important component of the grassland carbon sink. The sequestration of PhytOC is important for maintaining the dynamic balance of the carbon cycle within grassland ecosystems. However， the sequestration of PhytOC in grassland ecosystems has not received enough attention and remains insufficiently studied. In this study， we reviewed the current research progress on terrestrial ecosystem PhytOC， analyzed the formation and sequestration of plant PhytOC， the accumulation and stability of soil PhytOC， and the distribution and storage of PhytOC across different grassland types. We also discussed the impacts of human activities and global climate change on grassland PhytOC. Furthermore， the future research directions for PhytOC in grassland ecosystems were also proposed. An in-depth study of PhytOC in grassland ecosystems can provide a theoretical basis for accurately estimating the carbon sequestration potential of phytolith under the background of global climate change， and this could further enhance the carbon cycle model of ecosystems.

Salt stress leads to the accumulation of reactive oxygen species （ROS） in plants， causing damage to plant cells. However， the enzymatic antioxidant system is responsible for scavenging ROS in plant cells and protecting cells from ROS damage. At present， there are few functional analyses of genes related to ROS-scavenging enzymes in alfalfa （Medicago sativa） in response to salt stress. Based on the transcriptome data of roots and leaves of salt-tolerant alfalfa cultivar （GIB） and salt-sensitive cultivar （LS） under salt stress， this study identified 28 differentially expressed genes related to ROS-scavenging. Twenty-eight genes are distributed on 19 chromosomes， belonging to five gene families： MsGST， MsPOD， MsAOX， MsGRX and MsPrdx， among which MsGST （12） and MsPOD （11） families account for the largest proportion. The physicochemical properties of ROS scavenging enzyme proteins were different among the members of each gene family. There were highly similar conserved motifs in the members of the gene family. Phylogenetic analysis showed that MsGSTUs and MsPODs were located in the branches defined by Tau and AtPERs in Arabidopsis thaliana， respectively， suggesting that they had similar evolutionary processes and similar functions.Real-time fluorescence quantitative PCR analysis showed that the expression levels of MsGSTU26， MsPOD2 and MsPOD4 genes in GIB leaves under salt stress were significantly higher than those in LS， and the promoter regions of the three genes had elements （G-box and CGTCA-motif） related to adverse stress. It indicated that the MsGSTU26， MsPOD2 and MsPOD4 genes may be involved in the regulation of the adaptability of GIB and LS to salt stress.

Leymus chinensis is an important native forage grass species in China， yet its low seed setting rate greatly constrains large-scale production and utilization. To identify the key traits influencing seed setting and to evaluate their relative contributions， this study examined 100 Leymus chinensis germplasms collected from different geographic origins. Fifteen traits closely related to seed setting were measured， including seed number， spike weight， seed weight， floret number， spikelet number， spike length， number of spike knots， vegetative plant height， reproductive plant height， leaf length， leaf width， seed setting percentage， thousand seed weight， and the number of vegetative and reproductive branches. The results showed that there was substantial genetic variation among the germplasms， with coefficients of variation for the 15 traits ranging from 10.88% to 56.05%. Correlation analysis showed that spike weight， seed number， seed weight， and thousand seed weight were significantly and positively correlated with seed setting rate， indicating their central roles in reproductive success. Multiple regression and hierarchical partitioning analyses demonstrated that seed number had the greatest contribution to seed setting rate， accounting for 31.57% of variation. Principal component analysis indicated that the first five principal components collectively explained 78.126% of the total variance. Based on a comprehensive evaluation of these traits， ten germplasms （77， 23， 24， 37， 35， 20， 57， 10， 22， 7） were identified as superior germplasms with high reproductive potential and stable performance across multiple traits.

Grassland restoration is a critical pathway toward achieving sustainable utilization and high-quality development goals for degraded ecosystems. While scientific evaluation of restoration outcomes provides essential evidence for optimizing rehabilitation strategies， current methodologies predominantly focus on pre- and post-restoration changes in individual or limited indicators （e.g.， biomass， vegetation coverage）， with insufficient attention to comprehensive multi-indicator assessments. To address this issue， this study used factor analysis to comprehensively evaluate eight restoration approaches and nine ecological restoration effect assessment indicators for degraded grasslands in Chen Barag Banner， Inner Mongolia， aiming to identify representative community assessment indicators and suitable restoration approaches. The findings demonstrated that： （1） Three critical indicators-vegetation coverage， aboveground biomass， and community species richness-were identified as representative metrics for restoration evaluation. （2） The integrated approach combining fencing with root pruning， fertilization， and sustained management practices demonstrated superior restoration effectiveness. Our comprehensive quantitative assessment methodology exhibited both scientific rigor and practical applicability. These findings provide an evidence-based framework for evaluating and managing grassland restoration initiatives in Inner Mongolia's degraded steppes and comparable ecoregions.

Heat shock transcription factors （HSFs） play crucial roles in plant growth and development， as well as in responses to biotic and abiotic stresses. In this study， we identified the MruHSF gene family in Medicago ruthenica using genomic data and conducted bioinformatic analyses. The expression patterns of MruHSF gene under drought stress were comprehensively analyzed through transcriptomic data and quantitative real-time PCR （qRT-PCR）， preliminarily exploring their potential roles in drought stress responses. The results showed that 27 MruHSF family members， with encoded proteins ranging from 97 to 505 amino acids （aa）， isoelectric points （pI） between 4.64 and 8.72， and molecular weights of 10 998.3 to 55 296.45 Da. Except for three unassigned gene， the remaining MruHSF genes were distributed across eight chromosomes. Phylogenetic analysis classified them into three evolutionary clades. Conserved motif analysis revealed that all MruHSF proteins except MruHSF02， MruHSF03， and MruHSF27 contained Motifs 1， 2， and 4， which were highly conserved in M. ruthenica HSF protein. Additionally， multiple cis-acting elements related to hormone response， light response， and abiotic stress were identified in the promoter regions of MruHSF genes. Expression analysis shows that MruHSF01， MruHSF08， MruHSF13， MruHSF16， and MruHSF22 exhibited significant differential expression under drought stress， suggesting their potential roles in the drought response mechanism of M. ruthenica.

To clarify the impact of wind turbines on biodiversity and soil properties of grasslands， this study took a wind power area with wind turbines installed and operated for 15 years in the temperate meadow steppe of Inner Mongolia as the research area， and selected a grassland without wind turbines as the control area. The plant community， insect community， soil microorganisms， and soil physical and chemical properties in the area were investigated， and the relationships among these factors were analyzed. The results showed that compared with the grassland in the control area， the vegetation coverage， aboveground biomass， and community diversity of the grassland in the wind power area decreased significantly （P<0.05）. The number of insects in the wind power area increased significantly （P<0.05）， but the diversity of the insect community decreased significantly （P<0.05）. The number of soil fungi and community diversity in the wind power area were all significantly reduced （P<0.05）.Soil moisture content， bulk density， total nitrogen， ammonium nitrogen， alkali-hydrolyzable nitrogen， total phosphorus， and total potassium in the wind power area were all significantly reduced （P<0.05）. Correlation analysis found that there was a significant relationship between soil physicochemical properties and soil microbial communities. Overall， during the operation period of wind power stations， it will cause the degradation of grassland plant communities， the loss of soil nutrients and reduce plant diversity， and lead to a homogenization of the insect community structure.

The desert steppe is increasingly affected by severe degradation， and enclosure has been recognized as an effective method for restoring degraded grasslands. Therefore， understanding the effects of enclosure on plant species diversity and aboveground biomass in desert steppes is essential for grassland conservation. This study investigated the effects of different enclosure durations （3 years， 13 years， 18 years， and 20 years） on plant communitiy characteristics， species diversity， and aboveground biomass in the Siziwang Banner and Zhurihe grasslands. The results showed that aboveground biomass exhibited an increasing trend with extended enclosure duration. The important values of perennial grasses， such as Cleistogenes songorica and Stipa breviflora， gradually increased， whereas those of degradation indicator species， including Salsola collina， Convolvulus ammannii， and Neopallasia pectinata， progressively declined， or even disappeared. Vegetation height and canopy coverage increased as enclosure duration extended. In plots enclosed for 13 years， the response ratios of the dominance index， diversity index， richness index， and evenness index reached their peak values. Meanwhile， in plots enclosed for 18 years， aboveground biomass attained its maximum value. A positive correlation was observed between aboveground biomass and the response ratio of the diversity index. This study provides scientific evidence for the restoration of desert steppe ecosystems， demonstrating that enclosure measures effectively promote ecosystem recovery and enhance vegetation community structure.

To investigate salt tolerance in alfalfa （Medicago sativa） germplasm， 30 alfalfa accessions of diverse origins were subjected to salt stress （200 mmol/L NaCl） for 15 days. Responses were evaluated through changes in seedling morphology， photosynthetic parameters， and physiological indices compared to control plants （CK， irrigated with Hoagland nutrient solution）. The results demonstrated that NaCl treatment decreased plant height， leaf area， leaf relative water content， root activity， shoot dry weight， chlorophyll a， chlorophyll b， transpiration rate， stomatal conductance， net photosynthetic rate， intercellular CO₂ concentration， water use efficiency， catalase （CAT） activity， and potassium （K⁺） content relative to CK. Conversely， root dry weight， root-to-shoot ratio， stomatal limitation value， proline content， malondialdehyde （MDA） content， peroxidase （POD） activity， superoxide dismutase （SOD）， sodium （Na⁺） content， and the Na⁺/K⁺ ratio exhibited increases. Regression analysis identified stomatal conductance， root activity， root-to-shoot ratio， and Na⁺ content as critical indicators for salt tolerance evaluation. The clustering analysis based on the comprehensive evaluation value of the membership function shows that the 30 alfalfa accessions were classified into four distinct tolerance categories： high salt-tolerant， moderately salt-tolerant， low salt-tolerant， and salt-sensitive. Accessions 7254 and 7657 exhibited high salt tolerance.

Warming and nitrogen deposition can affect the functions and structures of alpine meadow ecosystems on the Qinghai-Xizang Plateau. Ecological stoichiometry provides a framework to understand the biogeochemical cycling of nutrients between plant and soil. This study conducted a field experiment in an alpine meadow of Qinghai Province， to investigate the effects of different levels of warming and nitrogen deposition. The warming treatment included four levels： W0 （no warming）， W1 （air temperature increases 0.47 °C， soil temperature increases 0.61 °C）， W2 （air temperature increases 0.92 °C， soil temperature increases 1.09 °C）， W3 （air temperature increases 1.44 °C， soil temperature increases 1.95 °C）. Nitrogen application treatments included： N0 （no nitrogen application）， 16 kg N/（hm²·a）， and 32 kg N/（hm²·a）. The experiment assessed changes in carbon， nitrogen， and phosphorus contents in plant and soil， soil enzyme activity， and their stoichiometric ratios， as well as the relationship among these components. The results showed as follows： Warming significantly increased total nitrogen in the aboveground plant tissues， soil total nitrogen， soil organic carbon， the soil nitrogen phosphorus ratio， and the enzyme nitrogen phosphorus ratio. Simultaneously， it significantly decreased the carbon nitrogen ratio in aboveground plant biomass， and the carbon nitrogen and carbon phosphorus ratios of soil enzymes. Nitrogen deposition significantly increased total nitrogen in both aboveground and root tissues， soil organic carbon， soil total nitrogen， and the enzyme carbon nitrogen ratio. It significantly decreased the root carbon nitrogen ratio and enzyme nitrogen phosphorus ratio. The interaction between nitrogen deposition and warming significantly affected soil organic carbon content and the carbon nitrogen， carbon phosphorus， and nitrogen phosphorus ratios of soil enzymes. Analysis of stoichiometric homeostasis in plant tissues in responses to soil elements and enzyme activities revealed strict stoichiometric homeostasis in plant tissues under both warming and nitrogen deposition. Soil total nitrogen， soil carbon nitrogen ratio， and soil β-1， 4-xylosidase activity significantly influenced plant nutrient content and stoichiometry. In summary， short-term warming and nitrogen deposition significantly alter the stoichiometry of soil and enzyme systems in alpine meadows， which in turn influences the nutrient acquisition strategies of plants on the Qinghai-Xizang Plateau.

Nitrogen deposition represents a critical driver of nitrous oxide （N₂O） emissions in global terrestrial ecosystems， with profound implications for climate change prediction. Although numerous studies have investigated soil N₂O emissions patterns in response to nitrogen addition， controversies persist regarding the regulatory mechanisms and driving factors. Through a meta-analysis intergrading the 87 global studies， we demonstrate that nitrogen addition significantly enhances soil N₂O emissions. This effect is particularly pronounced under high nitrogen application rate （>200 kg/hm² year）， in low-precipitation regions （≤400 mm annual rainfall）， and with short-term and moderate-term nitrogen application （≤3 years）. Our analysis identified nitrogen input level， mean annual precipitation， and ecosystem type as the dominant factors controlling global N₂O emissions， providing a scientific foundation for developing targeted emission mitigation strategies.

This study investigated the effects of varying soil salinity levels on the growth and salt transport capacity of Suaeda salsa （L.） Pall. S. salsa was selected as the test species， and a barrel planting experiment was conducted with six salinity treatments： 10.21 g/kg （S1）， 20.92 g/kg （S2）， 30.29 g/kg （S3）， 40.55 g/kg （S4）， 50.36 g/kg （S5）， and a control treatment （CK） with 6.20 g/kg soil salt content. Plant growth parameters and salt transport capacity were assessed at four growth stages to identify optimal salinity conditions for S. salsa cultivation and ecological restoration in saline soils. The results showed that across all growth stages， the treatment with 20.92 g/kg soil salinity （S2） resulted in the most favorable growth performance for S. salsa， as evidenced by significantly higher plant height， stem diameter， fresh weight， and dry weight compared to other treatments. Specifically， at maturity stage， these parameters increased by 29.87%， 47.75%， 33.54%， and 19.45%， respectively， in the S2 treatment compared to CK. Increased soil salinity generally promoted stem and leaf succulence throughout the adult plant， flowering， and mature stages. Across treatments， a trend of decreasing succulence was observed from the seedling stage to the mature stage. Leaf tissue exhibited the highest salt transfer amount across all treatments， followed by stem and seed. As plants progressed through the growth stages， the ash content in all treatments decreased， likely due to dilution by increasing biomass. However， salt transfer amount continuously increased， reaching a peak at the mature stage. The S2 treatment displayed the greatest salt transfer amount （4250.41 kg/hm²）. These findings suggest that a soil salinity level of 20.92 g/kg promotes optimal plant growth status and salt transfer ability in S. salsa.

Fertilization is a key strategy for restoring degraded grasslands. To identify suitable nitrogen （N） and phosphorus （P） fertilization gradients for enhancing the productivity and soil characteristics of degraded alpine meadows， a lightly degraded alpine meadow in Dangxiong County， Xizang Autonomous Region， was selected for study. A two-factor randomized block design was employed， with four nitrogen levels （N0：0 kg N/hm²， N1：60 kg N/hm²， N2：90 kg N/hm²， N3：120 kg N/hm²） and four phosphorus levels （P0：0 kg P₂O₅/hm²， P1：30 kg P₂O₅/hm²， P2：60 kg P₂O₅/hm²， P3：90 kg P₂O₅/hm²）， resulting in 16 N-P treatments combinations， with N0P0 treatment serving as the control （CK）. Grassland productivity and soil characteristics were evaluated to determine the optimal N-P combinations. The results showed that the combined application of nitrogen and phosphorus fertilizers significantly enhanced aboveground biomass compared with the control， with the N2P2 and N2P3 treatments increasing biomass by 136.9% and 111.9%， respectively （P<0.05）. The combined application also improved soil organic carbon content， particularly in the 0-10 cm soil layer， where the N2P1 and N2P3 treatments reached 15.67 g/kg and 15.26 g/kg， respectively. Available phosphorus content was highest under N2P3 treatment in both 0-10 cm and 10-20 cm soil layers， while total nitrogen content was greatest under N3P1 treatment. Grey correlation analysis of aboveground biomass and soil characteristics （0-10 cm） indicated that N2P3 treatment provided the most favorable comprehensive improvement in productivity and soil nutrient status， followed by N3P3 treatment. Therefore， the combination of 90-120 kg/hm² nitrogen fertilizer with 90 kg/hm² phosphorus fertilizer is recommended as the optimal strategy for the restoration of degraded alpine meadows in Dangxiong County， Xizang Autonomous Region.

Salt stress is one of the most critical abiotic factors limiting plant growth and development. An in-depth understanding of the molecular mechanisms underlying salt tolerance in forage grasses is essential for the improvement of saline-alkali soils and the breeding of salt-resistant varieties. In this study， Festuca rubra L. was subjected to a series of salt concentration gradients to determine the concentration most sensitive to root response， which was identified as 100 mmol/L NaCl. Based on this， F. rubra roots exposed to 100 mmol/L NaCl were analyzed using RNA-Seq technology to elucidate transcriptomic changes under salt stress. A total of 43 091 differentially expressed genes （DEGs） were identified compared with the control group， including 16 486 significantly upregulated and 26 605 significantly downregulated genes. Gene Ontology （GO） enrichment analysis revealed that these DEGs were primarily enriched in intracellular signal transduction， protein transport， cytosol and GTPase activity. KEGG enrichment analysis showed that the DEGs were mainly involved in metabolic pathways such as the mitogen-activated protein kinase （MAPK） signaling pathway， endoplasmic reticulum protein processing， and the tricarboxylic acid （TCA） cycle. Within the MAPK signaling pathway， genes encoding MAPKs related to salt stress resistance were upregulated in F. rubra roots. Moreover， several transcription factor families， including C2H2， bHLH， NAC， MYB， WRKY， and bZIP， exhibited differential expression under salt stress， with members of the C2H2 family showing particularly strong responses. In conclusion， under 100 mmol/L NaCl stress， F. rubra roots primarily respond by upregulating MAPK gene expression， activating the MAPK signaling pathway， and regulating the activity of key transcription factors to enhance osmotic adjustment and salt tolerance.

Sandy land ecosystems play a critical role in the global carbon cycle， with their internal carbon cycling mechanisms being key to maintaining the global carbon balance. Soil organic carbon （SOC）， as the core component of this system， not only influences the cycling and turnover rates of soil organic matter but is linked to changes in the functional state of sandy ecosystems. It serves as a key indicator for assessing the health and stability to these systems. To gain a deeper understanding of SOC and its stability characteristics in sandy lands， relevant literature from 1998 and 2024 was compiled from the Web of Science （WOS） and China National Knowledge Infrastructure （CNKI） databases for analysis. The results showed that： （1） From 1998 to 2024， the number of publications on SOC in sandy lands showed an increasing trend. Domestic research hotspots focused on "soil nutrients" and "desertification"， while international hotspots were "nitrogen"，"carbon"， and "land use". （2） SOC content， storage， and its composition in sandy lands are influenced by various factors such as land use patterns， microbial activity， vegetation types， and human activities.（3） The stability of SOC in sandy lands results from the combined effects of physical， chemical， and biological protection. Physical protection （e.g.， aggregates） provides a microenvironment for chemical protection （e.g.， mineral adsorption）， while biological protection （e.g.， microbial activity） promotes aggregate various modern technological approaches to achieve long-term， spatially networked observation. In the future， multiple modern technological means should be integrated to achieve intelligent， networked， multi-scale and three-dimensional long-term positioning observations.It is also essential to develop and apply soil carbon sequestration techniques tailored to local conditions. This will help fully reveal the influencing factors and stabilization mechanisms of SOC in sandy lands， laying the foundation for achieving sustainable carbon sequestration goals in these environments.

The D27 （DWARF27） gene encodes an iron-containing β-carotene isomerase essential for strigolactone biosynthesis. In this study， the TpD27 gene was cloned from Trifolium pratense ‘Minshan’ using RT-PCR. Bioinformatics analysis revealed that the full-length coding sequence of TpD27 was 792 bp， encoding a 264-amino acid protein with a predicted molecular weight of 29.71 kDa， an isoelectric point of 8.76， and an instability index of 51.30， indicating that it was an unstable protein. Subcellular localization prediction suggested that TpD27 may be localized in the chloroplasts. The secondary structure of TpD27 was mainly composed of α-helix （33.71%） and random coil （55.68%）， consistent with its predicted tertiary structure. Phylogenetic analysis showed that TpD27 clusters closely with MtD27 from Medicago truncatula， indicating a close evolutionary relationship between the two species. Spatiotemporal expression profiling revealed tissue-specific expression of TpD27， with the highest transcript levels in flowers and the lowest in roots. Under abiotic stress conditions， TpD27 expression was significantly downregulated in response to cadmium， salt， and drought treatments. Under low-temperature stress， its expression followed a dynamic pattern： initial downregulation， subsequent upregulation， and eventual decline. The recombinant expression vector pCAMBIA2300-TpD27 was successfully introduced into wild-type Arabidopsis thaliana via Agrobacterium-mediated floral-dip transformation. Phenotypic analysis demonstrated that the transgenic Arabidopsis thaliana exhibited a significantly reduced number of branches compared to the wild-type plants.

This study employed multivariate statistical methods， including analysis of variance （ANOVA）， principal component analysis （PCA）， correlation analysis， hierarchical cluster analysis， and membership function evaluation， to comprehensively analyze and evaluate five seed morphological traits of 329 wildrye （Agropyron cristatum） accessions conserved in the National Crop GeneBank. The objective was to establish a theoretical framework for the evaluation and innovative utilization of A. cristatum （L.） Gaertn germplasm resources. The results showed that among the five phenotypic traits examined， thousand-seed weight exhibited the highest genetic variation， with a genetic diversity index of 1.880 and a coefficient of variation of 24.56%. The average genetic diversity index for all five traits was 1.752， and the average coefficient of variation of 14.06%. PCA extracted three principal components， explaining 98.750% of the trait variation， with the first three main components contributing 65.555%， 26.162%， and 7.034% respectively， effectively preserving the core genetic information of seed traits. Correlation analysis demonstrated extremely significant positive correlations between seed length with the other four phenotypic traits （P<0.01）. Additionally， significant positive correlations were observed between seed width and both thousand-seed weight and single-seed area （P<0.01）， between thousand-seed weight and seed length-width ratio， as well as between seed length-width ratio and single-seed area. Hierarchical cluster analysis categorized the accessions into four groups： Group Ⅰ （284 accessions， moderate）， Group Ⅱ （41 accessions， small-grained）， and Groups Ⅲ and Ⅳ （two high-quality unique accessions each）. Comprehensive evaluation using the membership function identified B-288， B-243， B-233， and B-250 accessions with excellent performance in seed length， seed width， single-seed area， and thousand-seed weight. In contrast， B-152， B-143， B-128， B-149， B-141， and B-153 accessions exhibited relatively weak performance across multiple traits. In conclusion， seed length， single-seed area and thousand-seed weight were identified as the key morphological indicators contributing to the genetic diversity of A. cristatum germplasm.

Overgrazing will destroy grassland， aggravate vegetation degradation， and induce soil wind erosion. In this study， wind erosion monitoring was conducted on Stipabreviflora desert steppe under different grazing intensity （CK: control， LG: light grazing， MG: moderate grazing， HG: heavy grazing）. Plant community coverage was also measured to explore the patterns of aeolian sediment flux at sand collection height of 0-120 cm aboveground and its relationship with vegetation under different grazing intensities. The results showed that during the growing season of Stipa breviflora desert steppe： (1) Under different grazing intensities， the plant community coverage from May to October demonstrated the pattern of CK>LG>MG>HG. Under the same grazing intensity， it initially increased then decreased. (2) With the increase of grazing intensity， the total aeolian sediment flux rose gradually， with the value under LG， MG and HG reaching 1.40， 1.82， and 1.95 times of that under CK， respectively. (3) There was a significant negative correlation between plant community coverage and total aeolian sediment flux across all grazing intensities （P<0.05）. (4) The functional relationship among grazing intensity （G）， plant community coverage （C）， and total aeolian sediment flux （Q） was constructed： Q=（0.003 5G²－0.020 2G－0.032 7） C+（-0.251 2G²+1.478G+2.463 6）. The goodness of fit （R²） of plant community coverage and total aeolian sediment flux in CK， LG and MG was greater than 0.9， indicating high goodness-of-fit， while R² of HG was only 0.54， which offers a more integrated solution by striking a viable balance between aeolian sediment flux reduction and herder livelihood needs.Despite ideal windbreak and sand fixation performance of the CK and LG treatments， the MG treatment integrated the requirement of grassland ecosystem multifunctional role on aeolian sediment flux bloking and livelihood needs of herdsmen. This finding provides a scientific basis for exploring ecological protection and resource utilization in desert steppe， and has important practical value for establishing a sustainable and coordinated human-land grassland management framework.

This study focused on the moderately degraded alpine meadow in the eastern part of Qilian Mountains. A gradient of microbial fertilizer application rate was applied， namely CK （no microbial fertilizer）， BIM （7.5 g/m²）， BIIM （15 g/m²）， and BIIIM （22.5 g/m²）. The effects of different microbial fertilizer application rates on soil nutrient content， microbial community structure， and diversity of degraded alpine meadow were investigated. The results show that： In 0-10 cm soil layer， the soil nutrient content with microbial fertilizer application was significantly increased （P<0.05） compared with CK， with BIIM treatment showing the greatest effect. The contents of organic matter， available phosphorus， alkali hydrolyzable nitrogen， and available potassium were increased by 6.6%， 30.52%， 18.79% and 12.02%， respectively compared with CK； With the increase of soil depth， the effect of microbial fertilizer on soil nutrient content gradually declined； At the 20-30 cm depth， except for available potassium， no significant differences were observed among the treatments for any nutrients. The analysis of soil microbial community composition and diversity indicated that the effect of any bacterial fertilizer treatment on the diversity of fungal community was not significant， whereas the species richness of the bacterial community was significantly reduced by the BIIM treatment （P<0.05）. From the compositional perspective， the functional composition of microbial community was positively influenced by increasing the relative abundance of beneficial bacteria such as Penicillium， Mortierella， Bacillus， and Ferribacterium. Correlation analysis showed that the relative abundance of most beneficial bacteria was positively correlated with soil nutrient content. The results demonstrated that the application rate of 15 g/m² for the microbial fertilizer enriched with Bacillus subtilis， Bacillus mojavensis and Pseudomonas synxantha was effective. It significantly increased the content of key nutrients in soil and improved the soil microbial community structure， which could be applied in the restoration of regional degraded alpine meadow.

As a typical inland arid region， Xinjiang faces widespread soil challenges including desertification， salinization-alkalization， and fertility depletion， all of which significantly constrain high-quality forage production. To explore suitable strip planting patterns for high-quality forage in this region， this research was conducted during 2023-2024 on moderately saline-alkaline soil in Southern Xinjiang using drip irrigation under plastic mulch with precision seeding above mulch. With sorghum-sudangrass （Sorghum bicolor×Sorghum sudanense） monoculture （MS） and sesbania （Sesbania cannabina （Retz.） Pers.） monoculture （MC） as controls， four strip cropping patterns with different row ratios were established： 2∶2 （S₂C₂）， 4∶2 （S₄C₂）， 4∶4 （S₄C₄）， and 6∶4 （S₆C₄）. Fresh forage yield， quality， and agronomic traits of sorghum-sudangrass were determined using conventional methods. The results showed that the optimal row ratio configuration significantly enhanced the agronomic traits of sorghum-sudangrass， while both forage yield and quality in intercropping were improved. Under the S₄C₂ ratio， plant height of sorghum-sudangrass was the highest. The mixed fresh forage yield was also the highest， whose yield was 17.03% （P<0.05） higher compared with MS， with a two-year average of 127.16 t/hm². Crude protein content， neutral detergent fiber and acid detergent fiber content under S₄C₂ were higher compared with MS， whereas the pH was the lowest. Total volatile fatty acid content was relatively higher， with a two-year average of 147.76 mmol/L. Dry matter disappearance rate of S₄C₂ was significantly higher compared with other treatments （P<0.05）， with a 53.65 g/kg of two-year average. Maximum land equivalent ratio reached 1.22. Comprehensive evaluation revealed that the 4∶2 sorghum-sudangrass to sesbania strip intercropping ratio was the optimal recommended for application in arid desert oasis regions such as Southern Xinjiang.

Dof （DNA-binding with one finger） transcription factors are plant-specific regulators playing critical roles in plant response to environmental stresses. This study comprehensively identified MrDof gene family based on the genome-wide of Medicago ruthenica. We performed analyses including collinearity assessment， phylogenetic analysis， and chromosomal localization on the Dof family members. Furthermore， by integrating transcriptome data of M. ruthenica under drought stress and qRT-PCR validation， we explored the potential functions of these genes in drought stress responses. The results showed that a total of 33 MrDof genes were identified in M. ruthenica， and the number of amino acids encoded by these genes ranged from 157 to 492 aa. According to the evolutionary relationships among M. ruthenica， Medicago truncatula and Arabidopsis thaliana， these genes were classified into eight distinct groups （Group A， B1， B2， C1， C2.1， C2.2， C3， D1 and D2）. The 33 genes were unevenly distributed across nine chromosomes. Expression pattern analysis demonstrated that five genes （MrDof11， MrDof13， MrDof22， MrDof27， and MrDof30） were significantly induced by drought stress.

This study focused on cool-season turfgrass tall fescue （Festuca arundinacea） and perennial ryegrass （Lolium perenne）. The growth status， leaf water content， chlorophyll and malondialdehyde content， antioxidant enzyme activity， and other growth and physiological indicators of each turfgrass variety under shade stress were analyzed. A comprehensive evaluation was conducted by the membership function method. The results showed that shade stress inhibited all turfgrass varieties， resulting in a decrease in chlorophyll content， an increase in Malondialdehyde content， and activity enhancements of superoxide dismutase， peroxidase， and catalase， with differences among varieties. Comprehensive evaluation indicated that the shade tolerance of varieties ranked from strongest to weakest： ‘Lichuan’>‘Lightning’>‘Rebel Ⅳ’>‘War’>‘Tailv’>‘Rebel Ⅴ’>‘Essence’>‘Lvtuo’. In conclusion， perennial ryegrass ‘Lichuan’ and ‘Lightning’， and tall fescue ‘Rebel Ⅳ’ are identified as shade-tolerant turfgrass varieties.

To develop new soybean varieties with high feed value， Yuexia 106 and Aishengnidou， along with their F₂ population， were used as the mapping population. A total of 660 SSR markers， covering the entire soybean genome， were employed to map quantitative trait locus （QTLs） for eight key feeding traits of soybean， such as plant height， biological yield， acid detergent lignin （ADL）， relative feeding value （RFV）， and so on. The results showed that significant phenotypic correlations （P<0.05） were observed among biological yield， branch number on the main stem， number of nodes per main stem， plant height， neutral detergent fiber （NDF）， acid detergent fiber （ADF）， ADL， and RFV. A total of 18 QTLs were detected across six linkage groups （A1， B2， C1， C2， J， and L）. These included 2 QTLs for plant height， 1 for nodes per main stem， 3 for branch number on the main stem， 2 for biological yield， 3 for NDF content， 1 for ADF content， 3 for lignin content， and 3 for RFV. The phenotypic variance explained by individual QTL ranged from 2.11% to 59.77%， with qADF-l， qADL-a1， qADL-c2， qBY-j， qNBMS-l， qNDF-j， and qNNMS-l having phenotypic contributions greater than 15%.

Plant rhizosheath is the sheath-like structure tightly adhering to the root surface. The unique physical， chemical， and microbiological characteristics of the rhizosheath contribute to vital environmental and biochemical functions including rhizosphere soil aggregation， formation of soil aggregates， enhanced water and nutrient uptake， promotion of microbial colonization， and drought stress resistance. This review provides comprehensive understanding for the research status about rhizosheath in formation and the function and objectively demonstrates current research hot spot. CiteSpace software and bibliometric methods were conducted to retrieve a total of 2812 publications related to rhizosheath from January 1， 2008， to April 30， 2023 in Web of Science （WOS） Core Collection and China National Knowledge Infrastructure （CNKI） database with key words “Rhizosheath”， “Root hair”，“Root exudate”，‘Root sheath’， ‘Root secretion’， and ‘Root hair’. This review illustrates biological， chemical， and physical interactions determining rhizosheath development and plant absorption of water and nutrient from perspectives of plant rhizosheath formation and function. The review aims to provide guidance for further research on molecular genetic mechanisms of rhizosheath development and the application on crop breeding.

Annual pioneer plants play an important role in the revegetation of grassland open-pit coal mine dump， which can not only quickly form vegetation cover to prevent soil erosion， but also improve the soil ecological conditions for the establishment and stability of perennial plants. In order to explore the adaptability and the effect of soil improvement of annual pioneer plants in the coal mine dump， six annual forage soybean varieties （abbreviated as S001， S002， S003， S004， S005 and S006， respectively） were used as the pioneer plant materials in the dump of Xilin Gol open-pit coal mine in Inner Mongolia， to analyze the effects of different varieties of forage soybeans on soil nutrients and soil enzyme activities. The results showed that planting six forage soybean varieties improved the soil nutrient content and soil enzyme activity in the dump， but different varieties had different adaptability and the improvement effect was different. The soil of the dump field was infertile， and the planting improvement effect was not obvious in the first year. However， after two consecutive years of planting， the soil nutrient content and soil enzyme activity in the dump were significantly improved. TOPSIS comprehensive analysis showed that the score was S003>S005>S004>S002>S001>S006， and S003 was suitable to be the pioneer plant for revegetation in dump.

Soil organic carbon （SOC）， with its critical ecological functions， is a key indicator for assessing the effectiveness of ecological restoration in grassland surface mining areas. This review focused on the effects of ecological restoration on SOC， considering vegetation， soil， and soil microbial restoration. Plant， soil， and soil microorganism all influenced SOC dynamics in grassland surface mine， with soil microorganisms likely playing the most significant role in SOC changes. Additionally， this review identified existing challenges and proposed potential strategies to address issues related to plant， soil， and microbial restoration in these areas. The review also emphasized the importance of investigating the interactive effects between plant， soil， and soil microorganisms on SOC. This review provides theoretical insights to guide the rational implementation of ecological restoration practices and support further research development， technical advancement， and application on this field.

This research aims to investigate the effects of variations in precipitation on the ecological stoichiometry of soil organic carbon （SOC）， total nitrogen （TN）， and total phosphorus （TP） in desert steppes and to reveal the response of C， N， and P and their ecological stoichiometry to precipitation gradients in desert steppe ecosystems. The experiment was conducted in temperate desert steppe on the southern edge of Mu Us Desert， Yanchi County， Ningxia Hui Autonomous Region. Five precipitation levels， 33%， 66%， 100%， 133%， and 166% of natural precipitation （G1， G2， G3， G4， G5）， were simulated by rainout shelters and manual water replenishment. Variation patterns of SOC， TN， TP contents across soil layers （0-10 cm，10-20 cm， and 20-30 cm） were analyzed under different precipitation levels. The results indicate that： （1） When precipitation increased （G4）， the SOC， TN， and TP contents， and soil C∶P and N∶P ratios in 10-20 cm and 20-30 cm soils were significantly lower than in 0-10 cm soils （P<0.05）. However， the TP content did not respond significantly to precipitation changes. （2） With the increasing of soil layer depth， the correlation between the contents and ratios of SOC， TN， and TP within soil followed the order of 20-30 cm>10-20 cm>0-10 cm； （3） The variation in the SOC， TN， and TP contents was the highest in the 20-30 cm layer， followed by the 10-20 cm， and was the lowest in 0-10 cm. The variation of soil TP content was the least for all the three soil layers. In conclusion， precipitation changes have a significant impact on the ecological stoichiometry of soil carbon， nitrogen， and phosphorus， and the variation of carbon， nitrogen， and phosphorus in deep soil is greater. Deep soil （20-30 cm） is more responsive to precipitation changes than surface soil （0-20 cm）， indicating that the ecological stoichiometry of desert steppe soils is more sensitive to precipitation in deeper layers.

Grazing can alter the structure and function of grassland ecosystems. Currently， research on the impact of grazing on soil bacterial communities primarily focuses on the effect of grazing intensity on surface soil. However， the effects of grazing intensity on bacterial community structure in different soil layers remain unexplored. This study aimed to provide a theoretical basis for the protection and sustainable use of desert steppe ecosystems by examining the impact of grazing intensity on soil bacterial communities at various soil depths. High-throughput sequencing was used to examine the diversity and composition of soil bacterial communities at different depths under five grazing intensities： no grazing （CK）， light grazing （LG）， moderate grazing （MG）， heavy grazing （HG）， and extremely heavy grazing （OG） in the desert steppe of Inner Mongolia. The results showed as follows： （1） Compared to CK， the LG treatment significantly increased the diversity of the soil bacterial community in the 0-20 cm soil layer. （2） At the phylum and genus levels， compared to CK， the relative abundance of Actinobacteriota and Rubrobacter significantly decreased in the 0-20 cm soil layer under all grazing intensities. Under LG treatment， the relative abundance of Proteobacteria significantly increased. In the 20-40 cm soil layer， the relative abundance of Acidobacteriota and the RB41 significantly increased under MG treatment， while the relative abundance of Rubrobacter significantly decreased under OG treatment. （3） Redundancy analysis （RDA） revealed that dissolved organic carbon， total nitrogen， water content， ammonium nitrogen， nitrate nitrogen， and pH were the main environmental factors influencing changes in soil bacterial α-diversity. Correlation analysis between soil physical and chemical properties and the relative abundance of soil bacteria indicated that bacteria abundance in different groups was most strongly associated with ammonium nitrogen， nitrate nitrogen， water content， and organic matter. This study highlighted the effect of grazing on the composition of soil bacterial communities in the Inner Mongolia desert steppe by altering soil physical and chemical properties. The findings have significant implications for the sustainable management of desert steppe ecosystems in Inner Mongolia.

While the beneficial effects of silicon addition on Poaceae species have been widely reported， its mitigating effects and mechanisms of phosphorus deficiency in legumes remain unclear. In this study， a pot experiment was designed to investigate the effects of silicon application on alfalfa （Medicago sativa L.） under phosphorus limitation. Two nutrient conditions （nutrient balance and phosphorus limitation） and three concentrations of potassium silicate （0， 1， and 2 mmol/L） were applied to determine the effects of silicon addition on the growth characteristics， photosynthetic parameters， and nitrogen and phosphorus stoichiometric traits of the alfalfa under phosphorus limitation. The results showed that alfalfa biomass， plant height， photosynthetic rate， stomatal conductance， transpiration rate， photosynthetic water use efficiency， and shoot phosphorus content were significantly reduced by phosphorus limitation， whereas the shoot N∶P ratio increased particularly when no silicon was added. Silicon addition significantly increased biomass， plant height， photosynthetic rate， stomatal conductance， transpiration rate， and shoot phosphorus content of alfalfa under phosphorus limitation， while the addition under nutrient-balanced condition reduced stomatal conductance without affecting other parameters. Correlation analysis further revealed that under phosphorus-limited conditions， shoot silicon content was positively correlated with shoot phosphorus content and negatively correlated with the N∶P ratio. However， these correlations were not observed under nutrient-balanced conditions. Therefore， phosphorus limitation of alfalfa can be mitigated by silicon addition. Results demonstrated the associated mechanisms driving internal nutrient homeostasis from a stoichiometric perspective， and provided guidance and theoretical basis for the utilization of silicon in alfalfa cultivation under phosphorus deficiency.

The objective of this study is to investigate the effects of different sowing rates and nitrogen application levels on the growth and feeding quality of Suaeda salsa under drip irrigation. A two-factor full-combination field experiment was conducted with sowing rates of 10， 20， and 30 kg/hm² of Suaeda salsa and nitrogen application rates of 100， 200， and 300 kg/hm². The results showed that sowing rate and nitrogen application level， as well as their interaction， significantly affected the growth， biomass， salt uptake， and water use efficiency of Suaeda salsa. Under the same nitrogen application level， forage quality， biomass， salt uptake， and water use efficiency first increased and then decreased with increasing sowing rate. In contrast， the partial fertilizer productivity significantly decreases， while the net profit first increased and then decreased. Improvement of the coordinated overall benefits of sowing rate and nitrogen application rate was revealed. Based on the multi-objective optimization of the spatial analysis method， net profit and salt uptake simultaneously reached over 98% of their maximum values when the seeding rate was 20.20~21.44 kg/hm² and the nitrogen application rate was 222.45~250.87 kg/hm². The results of this study can provide a reference for the ecological development and utilization of saline-alkali land in arid areas.

In order to screen out the optimal oat mixed-sowing combinations and planting ratio in the Horqin Area， this study used mixture of oat （Avena sativa L.） with forage peas （Pisum sativum L.）， crimson clover （Trifolium incarnatum L.）， and common vetch （Vicia sativa L.） to explore the effects of different oat-legume combinations and different seeding ratios on forage growth performance， yield， and nutritional quality. The results showed that： the combinations of oat-crimson clover and oat-common vetch achieved the highest hay yield at a 5∶5 seeding ratio. In contrast， oat-forage pea at 8∶2 ratio produced the highest hay yield， with a significantly greater system productivity compared with the other mixtures. The nutritional quality of the forage mixture improved with increasing legume proportion in the seeding ratio， whereas the oat-crimson clover mixture had lower nutritional quality compared with the other two mixtures. In the grass-legume interspecific relationships， oats were the dominant species which made the largest contribution to the total forage yield. In conclusion， the combinations of oats + forage peas， oats + crimson clover， and oats + common vetch achieved relatively high hay yields at seeding ratios of 8∶2， 5∶5， and 5∶5， respectively， which were suitable for widespread planting in Horqin Region.

This research was conducted in the Stipa breviflora desert steppe of Siziwang Banner， Inner Mongolia. We established four stocking-rate treatments 0， 0.91， 1.82， and 2.71 sheep/（hm²·a） and plant community was categorized into five plant functional groups-perennial rhizomatous grasses， perennial forbs， perennial bunchgrasses， annual–biennial herbs， and shrubs/sub-shrubs. Quadrat sampling was used to measure plant height， cover， density， above-ground biomass， and species composition in August 2022. We calculated importance values and applied principal component analysis （PCA） to evaluate productivity-diversity coupling. Results showed that：（1） Species richness exhibited a hump-shaped response to stocking rate （22， 24， 22， and 21 species， respectively）， while morphological traits and productivity of the plant functional groups generally declined with increasing grazing pressure. （2） Importance-value analysis showed that the relative importance of perennial bunchgrasses increased from 40% to 68%， while their contribution to community productivity rose from 60% to 95%. PCA further indicated that productivity and diversity together accounted for 66.12% of the variance， which was primarily driven by this functional group.（3） A positive linear relationship was observed between species richness and productivity in the perennial forb group under no grazing， light grazing， and moderate grazing， whereas this relationship under heavy grazing was found in shrubs/sub-shrubs group. No other functional groups exhibited significant correlations. These results demonstrate that while stocking rate significantly alters plant functional group composition， species diversity alone is not a direct determinant of productivity， indicating complex interactions among disturbance， diversity， and productivity. Since perennial bunchgrasses play a crucial role in supporting productivity at higher stocking rates， grazing management strategies should prioritize the conservation and regulation of this functional group to ensure sustainable use and the ecological stability of the desert steppe.

Mowing is a common management and utilization method in grasslands. Understanding the ecological adaptive strategies of plant to mowing disturbance is the prerequisite for scientific implementation of mowing management. This study was conducted using a pot controlled experiment to investigate the effects of three mowing intensities on the functional traits and compensatory growth of Cynodon dactylon and Lolium perenne. The results showed that with the increase of mowing intensity， plant height， leaf area， root length， and root surface area of both C. dactylon and L. perenne decreased significantly. After 15 days of mowing， the tiller number of C. dactylon significantly increased under moderate and high mowing intensities， while mowing significantly increased the growth rate of both species. The aboveground biomass of both C. dactylon and L. perenne reached the peak under light mowing intensity， which was significantly higher compared with that of the control. The specific root length of C. dactylon， and the specific leaf area and specific root length of L. perenne were significantly decreased with the rising mowing intensities. The compensation index of C. dactylon was the highest under light mowing， whereas L. perenne had the highest compensation index under moderate mowing. Both species demonstrated compensatory growth in plant height under their respective mowing intensities， reaching overcompensation levels. Based on the integrated responses of traits including tiller number， growth rate， biomass and its allocation， post-mowing response of C. dactylon primarily is characterized by increases in tiller number and growth rate， whereas under light to moderate mowing， L. perenne exhibited increased aboveground biomass， a reduced root：shoot ratio， and higher growth rates during late growth. This suggests that the two species may achieve compensatory growth through different trait adjustments.

This study focused on root tips from four forage species in the Poaceae （Gramineous） family， including three accessions of Leymus chinensis （No. 16， No. 22 and No. 45）， one of Elytrigia repens （L2）， two of Leymus secalinus （Q16 and D51）， and three of Psathyrostachys juncea （X8， X19 and P24）， with three individual plants examined per accession. The effects of sampling time， pretreatment reagents， and pretreatment time on chromosome preparation were investigated by the conventional root tip squashing method. Additionally， karyotype analysis and phylogenetic analysis were conducted. The results showed that： （1） The optimal sampling time was 9：00 to 11：00， with the highest frequency of both division cells and metaphase cells. A 36-hour pretreatment with ice-water mixture treatment significantly increased the proportion of metaphase cells and demonstrated wider applicability. High-quality chromosome preparation with better dispersion were obtained from root tips subjected to hydrolysis in 1 mol hydrochloric acid （HCl） for 20 min， soften in 45 % acetic acid for 60 min， and hypotonic in distilled water for 30 min. （2） The karyotype formulas of Leymus chinensis accessions 16， 22 and 45 were 2n = 4x = 28 = 22m （1SAT） + 6sm， 2n = 4x = 28 = 20m （2SAT） + 8sm and 2n = 4x = 28 = 22m （4SAT） + 6sm， respectively. Those of Elytrigia repens L2 and Leymus secalinus accessions Q16 and D51 were 2n = 4x = 28 = 22m （2SAT） + 6sm， 2n = 4x = 28 = 24m （4SAT） + 4sm （2SAT） and 2n = 4x = 28 = 24m + 4sm， respectively. Psathyrostachys junceav accessions P24 is 2n = 2x = 14 = 12m + 2sm and X8 is 2n = 2x = 14 = 10m + 4sm， and that of Psathyrostachys juncea X19 is 2n = 2x = 14 = 10m + 4sm. （3） All accessions exhibited a 2A karyotype. Psathyrostachys juncea X19， with the largest average arm ratio and karyotype asymmetry coefficient， was identified as the most highly evolved. In contrast， Elytrigia repens L2 was the least evolved. Accessions No.16 and No.45 of Leymus chinensis， and accessions No.Q16 and No.D51 of Leymus secalinus， showed closer genetic relationships within their respective speices.