Background Seed shattering limits the production of Elymus sibiricus L., and application of exogenous brassinosteroid significantly alleviates plant organ abscission.Methods To explore the potential regulatory network of brassinosteroid on seed shattering, the abscission zone of E. sibiricus cv. Lanyu No. 1 treated with 2,4-epibrassinolide (EBR) was analyzed from morphological, physiological, transcriptomic, proteomic, and histological perspectives in this study.Results As the dosage of EBR increased, the values of breaking tensile strength, auxin, gibberellin, and lignin showed a trend of an initial increase and then decrease, whereas abscisic acid levels, cellulase, and polygalacturonase activities showed the opposite trend, with significant correlations among different indicators. Differentially expressed transcripts (3645) and proteins (1124), including hub (75), and bridge (121) proteins, were identified in the abscission zone. The identified biosynthetic and metabolic pathways related to plant cell walls and hormones affect seed shattering. During abscission zone development, abscission zone cells in the control group gradually degraded, while this degradation was not significant under tested EBR doses at the same developmental stage, especially at 0.010 mg L-1 EBR.Conclusions This study provides new insights into the regulation of seed shattering in E. sibiricus by brassinosteroids, and findings will also be applicable to other Triticeae species.
Abstract Background Sunn hemp (Crotalaria juncea L. and Crotalaria ochroleuca G. Don) was evaluated as a warm‐season legume to mitigate the “summer slump” in Maine's forage production caused by heat and moisture deficit stress. Methods This study compared three cultivars: “Crescent Sunn,” “Loei,” and “Red Mini,” at 60 and 90 days after seeding over the 2024 and 2025 growing seasons to measure biomass, nitrogen (N) fixation, and nutritive value. Results Environmental conditions significantly impacted performance; biomass accumulation in 2024 was 4296 kg dry matter (DM) ha−1, whereas the drought‐stressed 2025 season produced 1099 kg DM ha−1. Notably, drought increased the percentage of N derived from the atmosphere (52% in 2025 vs. 33.8% in 2024) and improved forage nutritive value by increasing crude protein and digestibility. Crescent Sunn and Loei consistently outperformed Red Mini; across all cultivars, delaying harvest to 90 days increased total biomass but elevated lignin levels and reduced digestibility. Conclusions Sunn hemp is a resilient forage and N source for northern temperate regions; management should target a 60‐day harvest for high‐quality animal feed or a 90‐day harvest for maximum cover crop biomass.
Background Livestock grazing is a major driver of arthropod community dynamics in drylands; however, its effects across vegetation types and seasons remain poorly understood.Methods We investigated seasonal (spring and summer) grazing effects on ground-dwelling arthropod communities by focusing on herbivore, detritivore, and omnivore abundance in steppe and desert steppe ecosystems of Mongolian grasslands.Results Grazing consistently increased herbivore abundance across all contexts. In the steppe, however, grazing effects on detritivores and omnivores were season-dependent: detritivore abundance declined under grazing only in summer, while omnivore abundance increased only in summer. These patterns likely reflect minimal grazing-induced changes in vegetation height during spring, when vegetation is not fully developed. In the desert steppe, seasonal interactions were weak, likely due to sparse vegetation limiting seasonal variation.Conclusions Grazing effects on arthropod communities vary with seasonal vegetation dynamics and differ between vegetation types. Accounting for seasonal variability is important for conserving arthropod communities in rangelands under climate change.
The United Nations has designated 2026 as the International Year of Rangelands and Pastoralists, drawing attention to the importance of grasslands and the communities that rely on them. Rangelands cover 54% of Earth's land surface, including grasslands, savannas, shrublands, deserts, and tundra; yet, grasslands remain chronically undervalued, leading to degradation and fragmentation. Grasslands are critical ecosystems that complement forests. While forests excel in above-ground carbon storage, grasslands outperform them in soil carbon sequestration, water retention, and drought resilience. Both deserve equal priority in conservation efforts. Global data reveal clear allometric relationships between grassland, forest, and national land areas. Notably, China, despite leading the world in planted forest area, has a critically low planted grassland coverage of just 0.22%, far below the expected level. From these allometric relationships, it is suggested that China would require an additional 93 400 km2 of planted grassland to achieve a target of 3.55% of the total grassland area. In this milestone year, we advocate for the creation of stronger, science-based policies aimed at protecting and restoring global grassland ecosystems. Importantly, for China, this encompasses the scientifically informed expansion of high-quality planted grassland to fulfill aspirations for aesthetic optimization of humanity's living space.
Background Improving the nitrogen use efficiency (NUE) of pastures has the benefit of reducing costs of production and reducing nitrogen loss to the environment. Genetic variation has been shown to exist for NUE, and hence NUE is a trait for breeding programs.Methods In this study, we develop genomic selection methods for NUE in perennial ryegrass through developing high-throughput sensor-based phenotyping and genotyping by sequencing (GBS) technologies. NUE of an advanced perennial ryegrass breeding population was screened in a spaced plant field trial which contained 644 genotypes, 3 nitrogen treatment levels (0, 20, and 40 kg ha-1 per application), and 3 replicates. The trial was conducted for 2 years with a total of 6 nitrogen applications. An unmanned aerial system (UAS) equipped with multispectral sensors was deployed weekly over the trial. Approximately 4-5 weeks after nitrogen fertilizer application, 75-675 selected samples were cut for ground truthing. Prediction models for biomass were developed based on spectral and ground truth data and biomass for each plant was computed. Plants were genotyped by GBS transcriptomics.Results NUE, defined as biomass production per unit of N application, varied significantly with N application level, season and among genotypes. Moderate broad-sense heritability (0.61-0.72) for NUE was observed. Genomic prediction accuracies were in the range of 0.3-0.5.Conclusions Our results demonstrated that genomic selection for NUE was possible. The genomic prediction developed in these advanced breeding lines may be tested in other genetic backgrounds. The technologies are ready to be extended into other perennial pasture grass species.
Background Alfalfa is one of the most important forage crops in the world, and its performance is significantly affected by salt stress. Although plant growth promoting rhizobacteria (PGPR) can alleviate salt stress, their colonization in the rhizosphere is often compromised by high salinity. Exopolysaccharides (EPS) not only enhance the stress resilience of PGPR but also directly improve plant salt tolerance. Consequently, a thorough investigation of the synergistic effects between EPS and PGPR is of significant theoretical and practical importance for developing advanced microbial fertilizers.Methods To investigate the underlying mechanisms, we applied salt stress using NaCl and introduced EPS isolated from Erwinia persicina strain Cp2 (Cp2-EPS). The effects of co-inoculation of Cp2-EPS alone and Bacillus DN2 on the growth and salt tolerance of alfalfa were investigated.Results Pot experiments demonstrated that co-inoculation exerted stronger effects than single treatments, with Cp2-EPS showing a more pronounced impact than DN2 alone. The alfalfa seedlings after combined inoculation showed increased photosynthesis and greater accumulation of osmotic substances, such as proline, soluble sugars, and soluble proteins. Increased activity of superoxide dismutase and catalase effectively reduced cell membrane damage, enhanced the ability to scavenge reactive oxygen species, and alleviated oxidative stress symptoms in plant cells. The colonization density of DN2 in the alfalfa rhizosphere from the co-inoculation was significantly higher than that in the single DN2 inoculation.Conclusions Alfalfa salt tolerance and productivity were synergistically enhanced by Cp2-EPS through its promotion of Bacillus DN2 colonization and persistence in the rhizosphere.
Background Forage perennial ryegrass (Lolium perenne L.) has been extensively researched regarding vegetative growth and quality, with its seed being relatively unexplored. The declining viability of Epichlo & euml; fungal endophytes in ryegrass seed during storage underscores the need for dedicated biochemical research.Methods We conducted a lipidomic investigation of seeds from five fungal endophyte-perennial ryegrass associations: tetraploid ryegrass cultivars KLp1102, KLp1103 and KLp903 infected with the endophyte strain AR501 and cultivar KLp1102 independently infected with strain AR1 or AR37.Results Storage lipids in perennial ryegrass seeds were predominantly triacylglycerols (TGs) containing C18:2, C18:1, C18:3 and C16:0 fatty acyl chains. Notably, TGs and diacylglycerols (DGs) containing medium-chain fatty acids (C8:0, C12:0 and C14:0) showed differential accumulations among the seeds of the three cultivars infected with AR501, as well as among the seeds of KLp1102 infected with AR1, AR37 and AR501. The distinct responses of typical storage glycerolipids (C18 and C16 fatty acyl chains) and medium-chain glycerolipids (C8, C12 and C14) among KLp1102-AR1, KLp1102-AR37 and KLp1102-AR501 samples highlighted the influence of endophyte strains on host biochemistry. These findings suggest that medium-chain TGs and DGs play critical roles in maintaining effective ryegrass-endophyte associations.Conclusions This study identifies numerous structural and signalling lipid species, providing a foundational understanding of lipid composition in perennial ryegrass seed. The results offer new opportunities to investigate the mechanisms underlying endophyte viability during storage and to elucidate the genetic regulation of differentially accumulated signalling lipids across different ryegrass cultivars.
Background: Developing switchgrass (Panicum virgatum L.) cultivars with reduced nitrogen (N) demand is essential for sustainable biomass production. Conventional breeding under non-limiting N rates has increased yield but left unresolved the relationship between genetic diversity and nitrogen use efficiency (NUE). Methods: This study quantified genetic variation for biomass yield, N concentration, and N removal in two switchgrass populations that were evaluated for 2 years at two locations. A handheld near-infrared reflectance spectrophotometer (NIRS) was used to quantify biomass N content, and several selection criteria, that is, single-trait, ratio, and multi-trait index, were evaluated to model long-term gains. Results: Trait heritabilities were highest for N removal (0.41-0.67) and highly variable among the selection criteria. Biomass yield and N concentration were weakly and negatively correlated, whereas N removal was strongly positively correlated with both traits. Long-term predictions indicated that single-trait selection for yield would increase N demand by >100% over 20 cycles. Index-based selection outperformed single-trait selection with a favorable gain for biomass yield with reasonable increments to N demand. High predictive accuracies (>90%) were obtained with the handheld NIRS. Conclusions: Results demonstrate that multi-trait selection combined with portable NIRS could be effective in breeding switchgrass for improved NUE while maintaining high gains in biomass yield.
Background Freezing resistance is a critical but often overlooked trait that influences growing season-length and constrains plant distribution. A key limitation in its study is the prevalent reliance on excised tissues from cuttings, which bypasses whole-plant physiology. Whether this approach biases results by disrupting leaf-root hormonal signaling has not yet been tested.Methods Here, we used a unique dual-approach design comparing excised cuttings with intact transplanted individuals to directly test how sampling method affects the assessments of autumn freezing resistance in both leaves and roots.Results We detected no significant difference in autumn freezing resistance between the two sampling approaches. Roots, however, were significantly more vulnerable to frost than leaves. Although both tissue water content and carbohydrate levels were associated with freezing resistance, their interactive effect was significantly stronger in leaves, indicating divergent physiological stress-response mechanisms between above- and below-ground tissues.Conclusions Our study demonstrates that roots and leaves use distinct physiological strategies to cope with autumn freezing. This highlights the need to elucidate root-specific mechanisms of freezing resistance, especially given the projected loss of insulating snow cover under climate change.
Background: Nitrogen availability from mineralization of organic matter in managed forage and grazing lands can be substantial, but little is known of how it varies with management within and among farms within a region and across regions. Methods: Soil samples (n = 648) were collected at 0-10-cm depth under grasslands and woodlands across three physiographic regions of North Carolina, United States, which has a warm-humid climate. Potential C and N mineralization and inorganic N were classified by physiographic region, soil texture, and farm management to characterize influences. Results: Potential C and N mineralization were strongly associated across both grasslands and woodlands. Although physiographic region explained 27% +/- 5% of the variation in C and N mineralization, it was individual farm locations varying by management and soil type that contributed the most to this variation (48% +/- 2%), whereas field within a farm (11% +/- 3%) and duplicate sampling within a field (11% +/- 3%) were minor components. Soil-test biological activity was the best predictor of net N mineralization, with some modifications based on pasture age and quantity of hay fed on the farm. Apparent nitrification was inhibited under woodlands and in similar to 20% of samples under grasslands. Conclusions: Pasture age and management were key factors controlling C and N mineralization. Widely varying soil N supply from mineralization suggests that N fertilizer recommendations for pastures should be adjusted for soil texture and management conditions, and use of the soil-test biological activity assay could be a simple indicator of N availability to guide these recommendations.
Abstract Native grasses possess extensive ecological adaptability, such as cold, drought, and salt tolerance, and tolerance to poor soil conditions. They play a crucial role in ensuring food security and ecological security. However, their development and utilization are still limited by lack of information on agronomic cultivation methods, low seed production, and difficulty in commercial production. This review summarizes the core requirements for native grass breeding and practical solutions. A “six‐step” strategy for native grass breeding is proposed: (1) establish a basic agronomic cultivation system; (2) develop economically feasible seed production technologies to ensure farmers’ access to seeds; (3) systematically collect and evaluate germplasm resources in the target environment; (4) promote superior germplasm lines and achieve large‐scale seed production; (5) initiate selection/breeding plans for key traits such as seed yield, seedling vitality, and multi‐trait productivity; and (6) on this basis, strategically integrate advanced technologies such as genetic markers, gene editing, and omics analysis to accelerate the process of precision breeding. This progressive strategy emphasizes laying a solid foundation for breeding before applying newly emerging technologies to cultivate native grass varieties with commercial value.
Background The plant-microbe interaction between tall fescue and its endophyte Epichlo & euml; coenophiala can affect ecosystem responses to changing rainfall patterns and increasing temperatures. Endophyte-infected (E+) stands often exhibit improved stress tolerance and differing soil greenhouse gas (GHG) emissions compared to endophyte-free (E-) stands. However, it is unknown if mammalian nontoxic endophyte (NTE) strains introduced into some tall fescue cultivars confer differing stress tolerances or reduce soil GHG emissions.Methods We quantified the impact of fescue-NTE symbioses in Jesup and Texoma on biomass and GHG emissions in response to increased temperature (+3 degrees C) and altered precipitation (50% lengthened interval between events) using a factorial design in the United States southeastern transition zone over 2 consecutive years (2016-2017).Results Endophyte infection increased aboveground biomass 24% across years, whereas heat decreased aboveground biomass 17% across tall fescue cultivars and years. Endophyte infection reduced CO2 emissions under both ambient (for Jesup) and heated conditions (for Texoma), but endophyte infection also increased NH3 volatilization for Texoma (no effect for Jesup), especially under the hottest and driest treatment.Conclusions Fescue-NTE symbioses may improve pasture resiliency with projected climate change for the study region.
Background Shrub encroachment (SE) drives rangeland degradation, threatening biodiversity and forage productivity. The reversal of the catastrophic effects of SE depends on the efficacy of restoration efforts. We evaluated the potential of manual removal of the shrub Pteronia incana (Burm.f.) DC. with or without reseeding mixtures of grasses (Panicum maximum Jacq. and Eragrostis curvula [Schrad.] Nees) on rangeland restoration at Peddie, Eastern Cape Province, South Africa.Methods The treatments were (1) uprooting and reseeding (UPR), (2) uprooting only (UPO), (3) cutting and reseeding (CR), (4) cutting only (CO) and (5) untreated control (CTL), each replicated three times in North and South aspects.Results Graminoid cover was higher in all treatments than in CTL, with CR showing relatively higher cover in North and South slopes. Restoration treatments increased plant density, richness and diversity compared to CTL. Slope aspect, treatment and seeded species interacted significantly on biomass production. CO in the North aspect attained two-fold higher biomass production of nonreseeded grasses than other treatments. Responses of reseeded species varied by aspect, with P. maximum attaining two-fold higher BP in CR and UPR in the North than the South slope, whereas E. curvula had higher biomass production in CR in the South than the North slope.Conclusions Shrub clearing facilitated restoration of diversity and plant densities regardless of the restoration method. However, biomass production and vegetation cover depended on the interaction of the shrub clearing method, reseeding and slope aspect. Thus, the decision on restoration of herbaceous vegetation should be informed by the vegetation attribute of restoration priority.
Background: Soil health describes critical soil functions influenced by land management. Although some key soil characteristics are inherent (such as texture, mineralogy, and landscape position), there are other soil properties and processes that are altered by land management (such as soil organic matter, nutrient concentrations, and the capacity to infiltrate and store water) to form the basis of soil health evaluation. Methods: This perspective overview of soil health in humid grazing lands focused on key soil health attributes that should be considered to evaluate the sustainability of forage and grazing lands. Soil compaction, nutrient concentrations, and organic matter, along with their biological fractions, were emphasized. Results: Soil bulk density is commonly measured to assess soil compaction. Density often increases with stocking rate, but it can be moderated by the accumulation of surface-soil organic C and N. Many soil nutrients are concentrated near the soil surface, but soil type and management can influence these distributions. Soil-test biological activity increases with time in forage management systems and is often greater with grazing than haying due to livestock excretal return to soil. Root-zone enrichment of soil organic C was enhanced under grasslands compared with croplands but lower than under woodlands. However, root-zone enrichment of total soil N was greater under grasslands than under other land uses, suggesting that the quality of organic matter under grasslands was greater than under woodlands, an essential feature that supports agricultural production Conclusions: This perspective overview of soil health in humid grazing lands illustrated the positive soil health benefits achievable with balanced agroecological farming approaches using forages.
Abstract The Qinghai–Xizang Plateau is a critical grassland region for China's ecological security and sustainable pastoral development. Its grassland animal husbandry currently confronts systemic challenges: extreme seasonal nutritional imbalance in forage, multi‑type consumer co‑grazing competition involving livestock, wild ungulates, rodents, and phytophagous insects, escalating ecology–production–livelihood tensions, and ongoing climate change. To address these challenges, this perspective proposes a framework for achieving high‐quality development of ecological conservation‐oriented grassland animal husbandry. The core objective is to shift from the singular pursuit of production efficiency to the integrated enhancement of both production and ecological functions. The main innovations of this work lie in (1) a multidimensional carrying capacity framework that integrates grass–livestock balance, protein balance, multi‑type consumer dynamics, and fodder supplement capacity; (2) a high‑yield, high‑quality cultivated grassland technology system to overcome seasonal nutrient deficits; and (3) three regional transformation models: the Hainan Prefecture Model focusing on synergy between ecological restoration and clean energy, the Biodiversity Conservation+ Model combining technology and multi‑stakeholder governance, and the Three‑Grassland‑Type Coupling Model for spatial optimization of nature reserve, livestock grazing, and cultivated grasslands. The resulting systematic pathway supports a sustainable development paradigm that harmonizes ecological security, resource efficiency, and socioeconomic benefits for the Plateau and similar alpine pastoral regions worldwide.
Abstract Heitutan, a term referring to extremely degraded alpine grassland on the Qinghai–Xizang Plateau, epitomizes a critical challenge in global ecological restoration. Likened to a “cancer cell,” Heitutan can gradually encroach on healthy grassland. Its widespread occurrence on the Qinghai–Xizang Plateau originates from the deep‐rooted paradox between natural and socio‐economic systems in alpine pastoral areas, which results in the structural and functional collapse of the ecosystem. Consequently, the ecological restoration of Heitutan involves the reconstruction of an integrated social–ecological system. From this perspective, this review synthesizes current understanding of Heitutan's formation mechanisms, restoration approaches, post‐restoration management models, and pertinent ecological ethics. We highlight that enhancing the scalability of in situ‐based restoration technologies, along with strengthening socio‐economic tolerance for trial‐and‐error and adaptive capacity within restoration zones, is vital for successful restoration. For the realistic requirement of long‐term restoration in the cold and high‐altitude region, we propose establishing a “Heitutan‐restoration grassland” system through reseeding with perennial native plants as a sustainable and practical framework. This system provides a viable pathway to combat grassland degradation. It enables government investment to effectively integrate the ecological construction with pastoral development within the Heitutan restoration engineering on the Qinghai–Xizang Plateau.
ABSTRACT Background The Qinghai–Tibet Plateau has significant grassland degradation. The plateau pika (Ochotona curzoniae Hodgson), a small burrowing mammal, traditionally viewed as a pest, may strongly shape vegetation, yet its fine‐scale spatial ecology remains unclear. Methods Using custom‐made wildlife trackers and high‐resolution multispectral unmanned aerial vehicle (UAV) mapping to quantify fine‐scaled movements, habitat utilization, and activity patterns of 10 plateau pikas in a summer pasture. Results Plateau pikas demonstrated scale‐nested habitat preferences: preferred fragmented vegetation at a 5‐m scale, while favoring larger vegetation patches at a 1‐m scale. Mean home range was 1633 m² (range 494–7443 m²), larger and more variable than prior reports. Activity patterns showed a distinct diurnal pattern, with aboveground activity from sunrise to sunset, and only belowground activity at night. Conclusions Integrating high‐resolution tracking with UAV yields novel, fine‐scale insights into plateau pika spatial ecology. Pikas in a summer pasture had larger, variable home ranges and were strictly diurnal. They employed a scale‐nested strategy, depending on a mosaic of vegetation and bare soil to provide foraging opportunities, safety from predators, and burrowing sites. These findings suggest that preventing the formation of optimal pika habitat through precise grazing management is an effective strategy to limit pika habitat use and abundance.
Abstract Background Grasslands provide key ecosystem services (ES), and yet, the cultural value linked to flower colour remains poorly quantified. This study presents a literature‐based approach to estimate human appreciation of flower colours in grassland as a cultural ES. Methods We introduce a flower colour appreciation value (FCAp value) that combines a flower colour appreciation index (FCAp index) with species abundances and flower colour area (FCAr). Four supramontane grasslands in Monti Sibillini (central Italy)—Bromopsis erecta Huds., Carex macrolepis DC., Sesleria nitida Ten. and Sesleria juncifolia Suffren—were selected, representing continuous and discontinuous grassland types. Results FCAp values peaked between May and July. Continuous B. erecta grasslands showed the highest values, while discontinuous S. juncifolia showed the lowest values. Green provided the largest contribution to total appreciation, whereas secondary colours (pink, yellow, purple and white) varied among grasslands. Blue, despite a high FCAp index, had limited influence due to low abundance and reduced FCAr. Conclusions Inherent limitations related to the colour appreciation scale and phenological uncertainty leave room for refinement: this rapid and standardised method provides a valid alternative to resource‐intensive field campaigns, particularly in remote or rugged study areas. It complements remote‐sensing and valuation approaches, enhances assessment of cultural ES and supports integration of landscape aesthetic values into grassland management and ES bundles.
Background. Himalayan grasslands are biodiversity hotspots vital for soil stabilization, carbon cycling and herbivore sustenance, and yet, studies on seasonal plant-soil-microbe dynamics remain limited in the Western Himalayas. Methods. We examined seasonal variations in vegetation, soil properties and microbial diversity in subalpine (SAL, Pir Chinasi) and alpine (AL, Ratti Gali) grasslands. Results. Vegetation communities shifted seasonally, with summer being dominated by Sibbaldia cuneata Hornem. ex Kuntze in SAL and Bistorta affinis (D. Don) Greene in AL, while winter shifted to Poa alpina in SAL. Biodiversity indices were greater (p < 0.05) in summer for SAL, while only richness differed seasonally in AL. Soil moisture correlated with soil organic carbon in winter (r = 0.642, p < 0.01) and in summer (r = 0.756, p < 0.001). Microbial alpha diversity peaked in summer, with communities dominated by Actinomycetota and Pseudomonadota. Microbial composition correlated with different soil properties seasonally with pH and micronutrients in summer and total potassium and phosphorus in winter. Beta diversity differed between grasslands (p = 0.001), while functional profiles remained stable seasonally, indicating metabolic resilience. Conclusions. Seasonal shifts and grassland type drive the structure of Himalayan ecosystems. Although plant and microbial communities were seasonally dynamic, their core metabolic functions were stable, indicating functional resilience essential for stability of the vulnerable high-altitude ecosystems.
