To accelerate the breeding of salt-alkali-tolerant alfalfa （Medicago sativa L.） varieties， in this study 19 alfalfa germplasms were used to establish a seedling-stage screening system for identifying salt-alkali-tolerant materials. By combining generation breeding， salt-alkali-tolerant alfalfa germplasms were rapidly propagated to obtain the first generation hybrid （F1）， which were subsequently evaluated for salt-alkali tolerance. The results showed that two-week-old alfalfa seedlings treated with 0.1 mol·L^-1 Na⁺ （NaCl∶NaHCO₃=1∶1， pH=8.5） for 72 h could be effectively used to screen salt-alkali-tolerant individuals. Evaluation of 19 alfalfa germplasms at the seedling stage revealed that cultivars ‘WL-168HQ’ ‘Galaxie Max’ and ‘Bara416’ exhibited significantly higher salt-alkali tolerance than the others. By adjusting the light quality ratio， the FCL5 light condition （450-465 nm （white light） 66.67%， 450-480 nm （blue light） 6.67%， 615-650 nm （red light） 26.66%） was identified as optimal， which supported healthy growth and high induction efficiency. Under FCL5 condition， 110 elite salt-alkali-tolerant plants were subjected to flowering induction and open pollination to produce F1 half-sib family seeds. Evaluation of six F1 half-sib families demonstrated that the proportions of salt-alkali-tolerant plants in ‘Octane’‘Bara416’ and ‘ZN-CT25’ families were significantly higher than those of unselected commercial cultivars. This study provides technical support and valuable germplasm resources for the breeding of new salt-alkali-tolerant alfalfa varieties.

This study aimed to assess the sustainability of alfalfa-grain maize rotations in central-northern Shanxi Province， China， and to screeen the optimal management strategies. The Agricultural Production System Simulator （APSIM） model was calibrated using multi-site experimental data and employed to simulate long-term historical （1985—2014） and future climate scenarios （2021—2050； 2051—2080）. Three rotation systems were compared： 6A （6-year continuous alfalfa）， 5A1C （5-year alfalfa+1-year grain maize）， and 4A2C （4-year alfalfa+2-year grain maize）. The results indicated that the model performed well in simulating yield and biomass （Normalized Root Mean Squared Error， NRMSE<20%）. Under future climate scenarios， the equivalent yield of 6A was significantly higher than that of 5A1C and 4A2C （P<0.05）， which were increased by 9.45% and 23.02% compared to 5A1C in the 2020s and 2050s， respectively and increased by 23.02% and 28.49% compared to 4A2C. Furthermore， 6A achieved the highest single-cycle equivalent yield （59.98 t/hm²） under the historical scenarios. Regarding precipitation matching， values exceeded 0.6 for maize and were >0.8 for alfalfa during May–August. However， the matching degree was lower in April， September， and October， indicating substantial irrigation requirements. The precipitation matching were significantly improved by future scenarios （P<0.05）， though the values of 6A remained lower than 4A2C during April and May. In conclusion， 6A maximized land productivity under future climates with enhanced irrigation in spring conversely. 4A2C offers a more balanced combination of productivity and water use efficiency. Our results could support the strategies of optimized forage and adaptive rotation strategy in Shanxi.

Saline-alkali land is widely distributed worldwide， and it is of great significance to screen for germplasm resources of saline-alkali resistant Bromus inermis for improving saline-alkali land In this study 100 Bromus inermis germplasm resources were selected as the reseat objects. During the seedling stage， 200 mmol·L^-1 NaHCO₃ solution was used for stress treatment， and 14 traits including plant height， root length， seedling fresh weight/dry weight， root fresh weight/dry weight were measured. Multiple statistical methods such as correlation analysis， principal component analysis， membership function analysis， and cluster analysis were used to comprehensively evaluate the alkali tolerance of different smooth brome germplasm resources. The results showed that there were varying degrees of variation in the alkali tolerance coefficients of 14 personality traits， ranging from 39.52% to 74.83%. Relative conductivity was negatively correlated with 13 indicators including plant height， root length， and seedling fresh weight. Using principal component analysis， 14 traits were classified into 3 components， with a cumulative contribution rate of 73.719%. Plant height， stem thickness， fresh weight of aboveground parts， dry weight of aboveground parts， survival rate， root surface area， root volume， and relative conductivity can be used as the main evaluation indicators for alkali tolerance at the seedling stage of smooth brome. Cluster analysis grouped 100 rootless barley seeds into three categories， including 16 alkali tolerant materials， 63 medium resistant materials， and 22 alkali sensitive materials. The results provide excellent germplasm materials for the screening of alkali tolerance indicators and the breeding of new varieties of smooth brome.

In order to explore the response of sagebrush deserts grassland community structure and biomass component allocation pattern of Seriphidium borotalense to degradation under different degradation degrees， the plant community characteristics， plant community diversity index， species diversity characteristics， and modular biomass allocation patterns of S. borotalense desert grassland in undegraded （UD）， lightly degraded （LD）， moderately degraded （MD）， and highly degraded （HD） areas were measured and analyzed. It was found that with the increase of degradation degree， the community height， coverage and aboveground biomass decreased significantly， and the density increased significantly （P<0.05）. The Patrick index did not change， and the other diversity indexes decreased significantly. The height， coverage and aboveground biomass of S. borotalense decreased significantly （P<0.05）， and the density reached the maximum at LD， but no S. borotalense was found at HD. The distribution of stem and leaf components such as plant height， stem length and leaf weight decreased significantly （P<0.05）， and the distribution of root components such as root weight， root diameter and root weight ratio reached the maximum at LD. Redundancy analysis showed that community coverage was the most critical environmental factor driving the component allocation pattern of S. borotalensei. To sum up， S. borotalense responded to grassland degradation by optimizing the component allocation pattern， and the optimization threshold was between LD and MD.

No-tillage reseeding is one of the important measures for improving degraded grasslands. This study focused on three types of temperate grasslands in the Ili River Basin of Xinjiang， setting up no-tillage reseeding and free grazing treatments. The aim was to investigate the effects of short-term reseeding treatment on plant communities， soil physicochemical properties， and plant-soil ecological stoichiometric characteristics， as well as to reveal the ecosystem’s internal stability response mechanisms. The results showed that no-tillage reseeding significantly increased aboveground biomass and community coverage， with community diversity significantly enhanced only in the temperate meadow steppe. The effects of no-tillage reseeding on soil physical properties varied across the grassland types. Plant carbon content significantly increased across all three grassland types， while nitrogen content significantly decreased， and the nitrogen-to-phosphorus ratio of vegetation significantly decreased. Soil organic carbon and total nitrogen both significantly increased， while total phosphorus showed no significant change. The soil carbon-to-phosphorus ratio in the temperate desert steppe and temperate grassland significantly increased， and nitrogen-to-phosphrous ratio increased significantly only in temperate desert steppe. Plant communities of all three grassland types exhibited “absolutely steady state” characteristics. In conclusion， no-tillage reseeding significantly enhanced grassland productivity by promoting community restoration and regulating soil nutrients. The responses of different grassland types to no-tillage reseeding vary， providing scientific evidence and theoretical support for the “differentiated zoning management” of grassland ecological restoration in arid and semi-arid regions.

To elucidate the initial effects of nitrogen deposition on soil organic carbon （SOC） and its stability in alpine meadows， we conducted a field nitrogen addition experiment in the eastern Qilian Mountains. Aboveground biomass， soil physicochemical properties， enzyme activities， and SOC fractions were measured， and their key drivers were identified using variance partitioning. Nitrogen addition significantly increased aboveground biomass but reduced cellulase and β-glucosidase activities （P<0.05）. Particulate organic carbon （POC） content and proportion decreased markedly， whereas easily oxidizable organic carbon （EOC） and mineral-associated organic carbon （MAOC） increased significantly （P<0.05）. POC dynamics were mainly regulated by total phosphorus and carbon-acquiring enzymes， MAOC was closely associated with aboveground biomass， pH， and β-glucosidase， while EOC was primarily driven by available phosphorus and cellulase. Overall， microbial biomass carbon （17%） and dissolved organic carbon （14.1%） primarily explained short-term SOC variations. In summary， nitrogen addition enhanced soil carbon pool stability by promoting plant carbon inputs， modulating enzyme activities， and reshaping the distribution of SOC fractions. These findings reveal the pathways through which nitrogen deposition stabilizes SOC in alpine meadows， providing critical insights into carbon cycling processes and the carbon sequestration potential of fragile ecosystems under nitrogen enrichment.

This study conducted a preliminary investigation on the rhizosphere fungi diversity of Kobresia humilis in the source region of the Yellow River， aiming to screen plant growth-promoting strains and provide basic materials for the future development of microbial fertilizers. Rhizosphere soil samples of K. humilis were collected from five different altitude sites in the source region of the Yellow River. Fungal strains were isolated and purified， then identified based on morphological and molecular biological methods. The plant growth-promoting activities of the dominant species Trichoderma paraviridescens were evaluated. A total of 207 fungal strains belonging to 18 genera were isolated. Among them， Fusarium and Trichoderma were the dominant genera， with 67 and 55 strains isolated， respectively， corresponding to isolation frequencies of 32% and 27%. Diversity index analysis revealed that the fungal diversity was the highest in Gonghe County （3208 m； H'=0.9381） and lowest in Maduo County （4512 m； H'=0.3378）. The overall fungal diversity in the study area was relatively low （H'=2.0809）. Both the diversity index and evenness index of rhizosphere fungi showed a trend of initial decrease followed by an increase with rising altitude. Analysis of the plant growth-promoting activities of the 55 T. paraviridescens strains indicated that 53 strains had the ability to produce cellulase， 51 strains possessed ability to produce protease， 32 strains had the ability to dissolve phosphorous， 6 strains had the ability to produce siderophores， and 4 strains had the ability to release potassium. These findings provide a theoretical basis and microbial resources for the exploitation of rhizosphere fungal resources of K. humilis and the development of microbial fertilizers in the source region of the Yellow River.

To comprehensively evaluate the differences in cadmium tolerance of different alfalfa （Medicago sativa L.） germplasms during seed germination， the indicators related to seed germination and seedling growth of 40 cultivars were measured under two conditions of control （distilled water） and cadmium stress （50 μmol·L^-1 CdCl₂） in this study. Based on the comprehensive indicator weight， membership function analysis and comprehensive evaluation value （D value）， the cadmium tolerance of the tested alfalfa germplasms was comprehensively analyzed. The results indicated that 50 μmol·L^-1 cadmium solution had inhibitory effects on nine indicators including seed vigor index， root length， and seedling vigor index of the tested alfalfa cultivars， with root length being the most inhibited. Based on the comprehensive evaluation of cadmium tolerance D value and systematic clustering analysis， the cadmium tolerance of 40 tested alfalfa germplasms was divided into three categories， namely strong cadmium tolerance （D≥0.691）， medium cadmium tolerance （0.691>D≥0.468） and weak cadmium tolerance （0.468>D）. The cultivars with the strongest and weakest cadmium tolerance were selected as ‘Bara520YQ’ and ‘WL298HQ’， respectively. This study provides a theoretical reference for screening and utilization of new germplasms of alfalfa with cadmium tolerance， the mining of cadmium tolerance genes， and the exploration of molecular regulatory mechanisms.

The Enhanced Vegetation Index （EVI） is a key indicator for characterizing vegetation activity and understanding the processes of the terrestrial ecosystem carbon cycle. Investigating its response to climate change helps deepen the understanding of vegetation-climate interaction mechanisms. This study focused on the Yin Mountain region of Inner Mongolia. Utilizing MODIS EVI datasets and meteorological data from 2001 to 2021， and employing methods such as trend analysis， partial correlation analysis， multiple linear regression， and partial least squares structural equation modeling （PLS-SEM）， we analyzed the spatiotemporal patterns of vegetation EVI and climatic factors in the region， and revealed the influence mechanisms of wind speed， precipitation， temperature， and solar radiation on EVI changes. The results indicated that from 2001 onwards， the annual mean EVI in the study area showed a fluctuating yet significantly increasing trend， with a slope of 0.002 74 per year （P<0.01）. The EVI increased from 0.172 in 2001 to 0.256 in 2021， representing a growth rate of 48.8%. Spatially， EVI increased gradually from northwest to southeast， with most areas showing a significant increasing trend， and the highest slope （>0.012） was observed in the south. Regarding the influencing mechanisms， EVI in the western and southern parts was primarily driven by wind speed and in the east by radiation， while in the north， it was jointly influenced by precipitation， radiation， and temperature. This research provides valuable insights for formulating regional ecological restoration policies.

The purpose of this study was to investigate the effects of different additives on the fermentation characteristics and microbial community of mulberry leaf silage. In this experiment， fresh mulberry leaves were served as raw materials， and six treatment groups were established， including control group （CK）， Pediococcus pentosaceus group （SSW）， Lactobacillus plantarum group （SSZ）， cellulase group （SSX）， Pediococcus pentosaceus+cellulase group （SSWX）， and Lactobacillus plantarum+cellulase group （SSZX）. Nutritional indicators， fermentation quality， and microbial diversity were assessed during a 45-day silage process at room temperature. The results revealed that the SSZX group exhibited the highest crude protein content （18.81% DM） and significantly reduced levels of neutral detergent fiber （NDF） and acid detergent fiber （ADF） （26.00% DM and 22.00% DM， respectively） （P<0.05）. Regarding fermentation characteristics， the additives markedly enhanced fermentation quality. The SSZX group recorded the lowest pH value （4.29）， the highest lactic acid content （39.90 g·kg^-1）， and the lowest ammonia nitrogen （AN） content （4.97 g·kg^-1）， without being detected butyric acid. In terms of microbial composition， the CK group was predominantly composed of Enterobacter （40.00%） and Fusarium （20.00%）， indicating a risk of spoilage. In contrast， Lactobacillus plantarum was the dominant bacterium in the SSZ and SSZX groups， comprising 75.00% to 84.00% of the microbial population. The abundance of Lactobacillus plantarum was significantly negatively correlated with both pH and NDF， thereby confirming its inhibitory effect on harmful microorganisms. In conclusion， the addition of Lactobacillus plantarum and cellulase to mulberry leaf silage had the highest quality.