Search Results (303)

Selenium stress can adversely affect plants by inhibiting growth, impairing oxidative stress resistance, and inducing toxicity. In this experiment, we investigated the effect of exogenous 24-epibrassinolide (24-EBL; 2.0 mg/L), a brassinosteroid (BR), on alleviating selenium stress in peach trees by analyzing its impact on biomass, selenium accumulation, and the expression of selenium metabolism-related genes in peach seedlings. The results demonstrated that 24-EBL could effectively mitigate biomass loss in peach seedlings exposed to selenium stress. Compared to the Se treatment alone, the 24-EBL+Se treatment resulted in a significant 16.55% increase in root selenium content and a more pronounced 30.39% increase in selenium content in the aboveground parts. Regarding the subcellular distribution, the cell wall was the primary site of Se deposition, accounting for 42.3% and 49.8% in the root and aboveground parts, respectively, in the Se treatment. 24-EBL further enhanced Se distribution at this site, reaching 42.9% and 63.2% in root and aboveground parts, respectively, in the 24-EBL+Se treatment. The 24-EBL+Se treatment significantly increased the contents of different chemical forms of Se, including ethanol-soluble, water-soluble, and salt-soluble Se. The quantitative real-time PCR (qRT-PCR) results indicated that the Se treatment promoted the expression of organic Se assimilation genes (SATs, OAS-TL B, and OAS-TL C), and 24-EBL application further increased their expression. Meanwhile, the Se-only treatment up-regulated the organic Se metabolism gene CGS1. Consequently, we propose that 24-EBL alleviates Se stress in peach seedlings by enhancing Se uptake and assimilation, and by adjusting subcellular distribution and chemical forms. Full article

Understanding species composition and forest dynamics is essential for predicting biomass productivity and informing conservation in tropical montane ecosystems. We evaluated floristic, demographic, and biomass changes in eighteen 0.1 ha permanent plots in the Colombian Sub-Andean forest, including both primary (ca. 60 y old) and secondary forests (ca. 30 years old). Two censuses of individuals (DBH ≥ 2.5 cm) were conducted over 7–13 years. We recorded 516 species across 202 genera and 89 families. Floristic composition differed significantly between forest types (PERMANOVA, p = 0.001), and black oak (Trigonobalanus excelsa Lozano, Hern. Cam. & Henao) forests formed distinct assemblages. Demographic rates were higher in secondary forests, with mortality (4.17% yr), recruitment (4.51% yr), and relative growth rate (0.02% yr) exceeding those of primary forests. The mean aboveground biomass accumulation and the rate of annual change were higher in primary forests (447.5 Mg ha⁻¹ and 466.8 Mg ha⁻¹ yr⁻¹, respectively) than in secondary forests (217.2 Mg ha⁻¹ and 217.2 Mg ha⁻¹ yr⁻¹, respectively). Notably, black oak forests showed the greatest biomass accumulation and rate of change in biomass. Annual net biomass production was higher in secondary forests (8.72 Mg ha⁻¹ yr⁻¹) than in primary forests (5.66 Mg ha⁻¹ yr⁻¹). These findings highlight the ecological distinctiveness and recovery potential of secondary Sub-Andean forests and underscore the value of multitemporal monitoring to understand forest resilience and assess vulnerability to environmental change. Full article

Grazing affects soil organic carbon (SOC) through plant removal, livestock trampling, and manure deposition. However, the impact of grazing on SOC is also influenced by multiple factors such as climate, soil properties, and management approaches. Despite extensive research, the mechanisms by which grazing intensity influences SOC density in grasslands remain incompletely understood. This study examines the effects of varying grazing intensities on SOC density (0–30 cm) dynamics in temperate grasslands of northern China using field surveys and experimental analyses in a typical steppe ecosystem of Inner Mongolia. Results show that moderate grazing (3.8 sheep units/ha/yr) led to substantial consumption of aboveground plant biomass. Relative to the ungrazed control (0 sheep units/ha/yr), aboveground plant biomass was reduced by 40.5%, 36.2%, and 50.6% in the years 2016, 2019, and 2020, respectively. Compensatory growth failed to fully offset biomass loss, and there were significant reductions in vegetation carbon storage and cover (p < 0.05). Reduced vegetation cover increased bare soil exposure and accelerated topsoil drying and erosion. This degradation promoted the downward migration of SOC from surface layers. Quantitative analysis revealed that moderate grazing significantly reduced surface soil (0–10 cm) organic carbon density by 13.4% compared to the ungrazed control while significantly increasing SOC density in the subsurface layer (10–30 cm). Increased precipitation could mitigate the SOC transfer and enhance overall SOC accumulation. However, it might negatively affect certain labile SOC fractions. Elucidating the mechanisms of SOC variation under different grazing intensities and precipitation regimes in semi-arid grasslands could improve our understanding of carbon dynamics in response to environmental stressors. These insights will aid in predicting how grazing systems influence grassland carbon cycling under global climate change. Full article

Quinoa (Chenopodium quinoa Willd.) has emerged as a climate-resilient, nutrient-dense crop with increasing global popularity because of its adaptability under current environmental variations. To address the limited understanding of quinoa’s genotypic performance under local agro-environmental conditions, this study hypothesized that elite genotypes would exhibit significant variation in agronomic, physiological, and biochemical traits. This study aimed to elucidate genotypic variability among 23 elite quinoa lines under field conditions in Faisalabad, Pakistan, using a multidimensional framework that integrated phenological, physiological, biochemical, root developmental, and yield-related attributes. The results revealed that significant variation was observed across all measured parameters, highlighting the diverse adaptive strategies and functional capacities among the tested genotypes. More specifically, genotypes Q4, Q11, Q15, and Q126 demonstrated superior agronomic potential and canopy-level physiological efficiencies, including high biomass accumulation, low infrared canopy temperatures and sustained NDVI values. Moreover, Q9 and Q52 showed enhanced accumulation of antioxidant compounds such as phenolics and anthocyanins, suggesting potential for functional food applications and breeding program for improving these traits in high-yielding varieties. Furthermore, root trait analysis revealed Q15, Q24, and Q82 with well-developed root systems, suggesting efficient resource acquisition and sufficient support for above-ground plant parts. Moreover, principal component analysis further clarified genotype clustering based on trait synergistic effects. These findings support the use of multidimensional phenotyping to identify ideotypes with high yield potential, physiological efficiency and nutritional value. The study provides a foundational basis for quinoa improvement programs targeting climate adaptability and quality enhancement. Full article

To clarify the ecological mechanisms underlying the succession of artificial grasslands to native alpine meadows and systematically reveal the patterns of ecological restoration in artificial grasslands in the Qinghai–Tibet Plateau, this study provides a theoretical basis for alpine meadow ecological restoration. In this study, artificial grassland and degraded grassland (CK) with different restoration years (20 years, 16 years, 14 years, and 2 years) in the Qinghai–Tibet Plateau were taken as research objects. We focused on the tillering characteristics, patch number, community structure evolution, and soil properties of the dominant species, C. alatauensis, and systematically explored the ecological restoration law by comparing and analyzing ecological indicators in different restoration years. The results showed the following: (1) With the extension of restoration years, the asexual reproduction ability of C. alatauensis was enhanced, the patches became large, and aboveground/underground biomass significantly accumulated. (2) Community structure optimization meant that the coverage and biomass of Cyperaceae plants increased with restoration age, while those of Poaceae plants decreased. The diversity of four species in 20A of restored grasslands showed significant increases (10.71–19.18%) compared to 2A of restored grasslands. (3) Soil improvement effect: The contents of soil organic carbon (SOC), total phosphorus (TP), nitrate nitrogen (NN), and available phosphorus (AP) increased significantly with the restoration years (in 20A, the SOC content in the 0–10 cm soil layer increased by 57.5% compared with CK), and the soil pH gradually approached neutrality. (4) In artificial grasslands with different restoration ages (20A, 16A, and 14A), significant or highly significant correlations existed between C. alatauensis tiller characteristics and community and soil properties. In conclusion, C. alatauensis in artificial grasslands drives population enhancement, community succession, and soil improvement through patch expansion. Full article

Nitrogen use efficiency remains the primary bottleneck for sustainable maize production. This study elucidates the functional mechanisms of the amino acid transporter ZmAAP1 in nitrogen absorption and stress resilience. Through systematic evolutionary analysis of 55 maize inbred lines, we discovered that the ZmAAP1 gene family exhibits distinct chromosomal localization (Chr7 and Chr9) and functional domain diversification (e.g., group 10-specific motifs 11/12), indicating species-specific adaptive evolution. Integrative analysis of promoter cis-elements and multi-omics data confirmed the root-preferential expression of ZmAAP1 under drought stress, mediated via the ABA-DRE signaling pathway. To validate its biological role, we generated transgenic maize lines expressing Arabidopsis thaliana AtAAP1 via Agrobacterium-mediated transformation. Three generations of genetic stability screening confirmed the stable genomic integration and root-specific accumulation of the AtAAP1 protein (Southern blot/Western blot). Field trials demonstrated that low-N conditions enhanced the following transgenic traits: the chlorophyll content increased by 13.5%, and the aboveground biomass improved by 7.2%. Under high-N regimes, the gene-pyramided hybrid ZD958 (AAP1 + AAP1) achieved a 12.3% yield advantage over conventional varieties. Our findings reveal ZmAAP1’s dual role in root development and long-distance nitrogen transport, establishing it as a pivotal target for molecular breeding. This study provides actionable genetic resources for enhancing NUE in maize production systems. Full article

Salinity stress is a primary abiotic constraint limiting global crop productivity, with progressive soil salinization inducing growth inhibition and physiological dysfunction in plants. Although melatonin (MT) has been extensively documented to enhance stress adaptation, the underlying mechanisms through which it mediates salt tolerance by integrating physiological processes remain unclear. This study investigated the effects of varying MT concentrations on photosynthetic performance, plant water relations, water-use efficiency, and stress-responsive physiological parameters in tomatoes, aiming to identify the key physiological pathways for MT-mediated salt stress mitigation. The results showed that salt stress significantly reduced the leaf relative water content and root hydraulic conductivity, suppressed the photosynthetic rate, and ultimately caused significant reductions in the aboveground and root biomass. MT spraying effectively improved leaf water status and root water uptake capacity, enhancing the photosynthetic rate and water-use efficiency, thereby providing material and energy support for plant growth. Furthermore, MT spraying increased the total antioxidant capacity in leaves and promoted the synthesis of phenolic and flavonoid compounds, thereby reducing oxidative damage. Simultaneously, it stimulated the accumulation of osmolytes to enhance cellular osmotic adjustment capacity and optimized ion uptake to maintain cellular ion homeostasis. Among the tested concentrations, 100 μM MT showed the most significant alleviative effects. This concentration comprehensively enhanced the salt tolerance and growth performance of tomato plants by synergistically optimizing water use, photosynthetic function, antioxidant defense, and ion balance. In conclusion, these findings provide experimental evidence for elucidating the physiological mechanisms underlying MT-mediated salt tolerance in tomatoes and offer theoretical references for the rational application of MT in crop production under saline conditions. Full article

To investigate the remediation efficiency of different plant species on cadmium (Cd)-contaminated soil, this study conducted a pot experiment with two woody species (Populu adenopoda and Salix babylonica) and two herbaceous species (Artemisia argyi and Amaranthus hypochondriacus). Soils were collected from an abandoned coal mine and adjacent pristine natural areas within the dam-adjacent section of the Three Gorges Reservoir Area to establish three soil treatment groups: unpolluted soil (T1, 0.18 mg·kg⁻¹ Cd), a 1:1 mixture of contaminated and unpolluted soil (T2, 0.35 mg·kg⁻¹ Cd), and contaminated coal mine soil (T3, 0.54 mg·kg⁻¹ Cd). This study aimed to investigate the growth status of plants, Cd accumulation and translocation characteristics, and the relationship between them and soil environmental factors. Woody plants exhibited significant advantages in aboveground biomass accumulation. Under T3 treatment, the Cd extraction amount of S. babylonica (224.93 mg) increased by about 36 times compared to T1, and the extraction efficiency (6.42%) was significantly higher than other species. Among the herbaceous species, A. argyi showed the maximum Cd extraction amount (66.26 mg) and extraction efficiency (3.11%) during T2 treatment. While A. hypochondriacus exhibited a trend of increasing extraction amount but decreasing extraction efficiency with increasing concentration. With the exception of S. babylonica under T1 treatment (BCF = 0.78), the bioconcentration factor was greater than 1 in both woody (BCF = 1.39–6.42) and herbaceous species (BCF = 1.39–3.11). However, herbaceous plants demonstrated significantly higher translocation factors (TF = 1.58–3.43) compared to woody species (TF = 0.31–0.87). There was a significant negative correlation between aboveground phosphorus (P) content and root Cd (p < 0.05), while underground nitrogen (N) content was positively correlated to aboveground Cd content (p < 0.05). Soil total N and available P were significantly positively correlated with plant Cd absorption, whereas total potassium (K) showed a negative correlation. This study demonstrated that woody plants can achieve long-term remediation through biomass advantages, while herbaceous plants, with their high transfer efficiency, are suitable for short-term rotation. In the future, it is suggested to conduct a mixed planting model of woody and herbaceous plants to remediate Cd-contaminated soils in the tailing areas of reservoir areas. This would synergistically leverage the dual advantages of root retention and aboveground removal, enhancing remediation efficiency. Concurrent optimization of soil nutrient management would further improve the Cd remediation efficiency of plants. Full article

Amid global environmental change, the intensification of nitrogen (N) deposition exerts critical impacts on the growth of forest vegetation and the structure and function of ecosystems in subtropical China. However, the physiological and growth response mechanisms of subtropical tree species remain poorly understood. This study explored adaptive mechanisms of typical subtropical tree species to N deposition, analyzing biomass accumulation, root plasticity, and nutrient/photosynthate allocation strategies. One-year-old potted seedlings of Phyllostachys edulis (moso bamboo) and Cunninghamia lanceolata (Chinese fir) were subjected to four N-addition treatments (N0: 0, N1: 6 g·m⁻²·a⁻¹, N2: 12 g·m⁻²·a⁻¹, N3: 18 g·m⁻²·a⁻¹) for one year. In July and December, measurements were conducted on seedling organ biomass, root morphological and architectural traits, as well as nutrient elements (N and phosphorus(P)) and non-structural carbohydrate (soluble sugars and starch) contents in roots, stems, and leaves. Our results demonstrate that the Chinese fir exhibits stronger tolerance to N deposition and greater root morphological plasticity than moso bamboo. It adapts to N deposition by developing root systems with a higher finer root (diameter ≤ 0.2 mm) ratio, lower construction cost, greater branching intensity and angle, and architecture approaching dichotomous branching. Although N deposition promotes short-term biomass and N accumulation in both species, it reduces P and soluble sugars contents, leading to N/P imbalance and adverse effects on long-term growth. Under conditions of P and photosynthate scarcity, the Chinese fir preferentially allocates soluble sugars to leaves, while moso bamboo prioritizes P and soluble sugars to roots. In the first half of the growing season, moso bamboo allocates more biomass and N to aboveground parts, whereas in the second half, it allocates more biomass and P to roots to adapt to N deposition. This study reveals that Chinese fir enhances its tolerance to N deposition through the plasticity of root morphology and architecture, while moso bamboo exhibits dynamic resource allocation strategies. The research identifies highly adaptive root morphological and architectural patterns, demonstrating that optimizing the allocation of elements and photosynthates and avoiding elemental balance risks represent critical survival mechanisms for subtropical tree species under intensified N deposition. Full article

Accurate estimation of forest aboveground biomass (AGB) and understanding its ecological drivers are vital for carbon monitoring and sustainable forest management. However, AGB estimation using remote sensing is hindered by signal saturation in high-biomass areas and insufficient attention to ecological structural factors. Focusing on Guangdong Province, this study proposes a novel approach that spatially extrapolates airborne LiDAR-derived Forest structural parameters and integrates them with Sentinel-1/2 data to construct an AGB prediction model. Results show that incorporating structural parameters significantly reduces saturation effects, improving prediction accuracy and AGB maximum range in high-AGB regions (R² from 0.724 to 0.811; RMSE = 10.64 Mg/ha; max AGB > 180 Mg/ha). Using multi-scale geographically weighted regression (MGWR), we further examined the spatial influence of forest type, age structure, and species mixture. Forest age showed a strong positive correlation with AGB in over 95% of the area, particularly in mountainous and hilly regions (coefficients up to 1.23). Species mixture had positive effects in 87.7% of the region, especially in the north and parts of the south. Natural forests consistently exhibited higher AGB than plantations, with differences amplifying at later successional stages. Highly mixed natural forests showed faster biomass accumulation and higher steady-state AGB, highlighting the regulatory role of structural complexity and successional maturity. This study not only mitigates remote sensing saturation issues but also deepens understanding of spatial and ecological drivers of AGB, offering theoretical and technical support for targeted carbon stock assessment and forest management strategies. Full article

The focus of this study was on young populations of Kandelia obovata within a constructed coastal wetland in Haicang Bay, Xiamen, Southeast China. The objective was to systematically examine their allometric growth characteristics and carbon sequestration potential over an 8-year monitoring period (2016–2024). Allometric equations were developed to estimate biomass, and the spatiotemporal variation in both plant and soil carbon stocks was estimated. There was a significant increase in total biomass per tree, from 120 ± 17 g at initial planting to 4.37 ± 0.59 kg after 8 years (p < 0.001), with aboveground biomass accounting for the largest part (72.2% ± 7.3%). The power law equation with D²H as an independent variable yielded the highest predictive accuracy for total biomass (R² = 0.957). Vegetation carbon storage exhibited an annual growth rate of 4.2 ± 0.8 Mg C·ha⁻¹·yr⁻¹. In contrast, sediment carbon stocks did not show a significant increase throughout the experimental period, although long-term accumulation was observed. The restoration of mangroves in urban coastal constructed wetlands is an effective measure to sequester carbon, achieving a carbon accumulation rate of 21.8 Mg CO₂eq·ha⁻¹·yr⁻¹. This rate surpasses that of traditional restoration methods, underscoring the pivotal role of interventions in augmenting blue carbon sinks. This study provides essential parameters for allometric modeling and carbon accounting in urban mangrove afforestation strategies, facilitating optimized restoration management and low-carbon strategies. Full article

Salinity has significant impacts on crops, a problem that is exacerbated under climate change conditions. For this reason, research is focused on possible ways to mitigate the impacts by adapting cultivation methods such as administering appropriate materials or formulations to plants. Therefore, this study investigated the effects of calcium (Ca²⁺) supplementation on the growth, physiology, and chemical composition of pomegranate plants (Punica granatum L. cv. ‘Wonderful’) grown under salinity stress. Young self-rooted plants were cultivated in pots containing a sand/perlite (1:1) mixture and irrigated with Hoagland’s nutrient solution amended with NaCl (0, 60, or 120 mM) and CaCl₂·2H₂O (0 or 10 mM). Salinity significantly reduced the fresh and dry weight of aboveground tissues; photosynthetic performance; chlorophyll content; and potassium (K), calcium (Ca), and magnesium (Mg) concentrations, particularly under high NaCl levels. Sodium (Na) accumulation increased in all plant parts, while nitrogen (N), manganese (Mn), and zinc (Zn) concentrations were elevated in basal leaves. Calcium supplementation mitigated several of these adverse effects, especially under moderate salinity. It helped maintain leaf biomass, supported K⁺ retention in roots, partially improved chlorophyll concentration, and limited Na⁺ accumulation in certain tissues. However, Ca²⁺ application did not consistently reverse the negative impacts of severe salinity (120 mM NaCl), and in some cases, interactions between Ca²⁺ and other nutrients such as Mg²⁺ were antagonistic. These findings confirm the inherent salt tolerance of pomegranate and demonstrate that calcium plays a partially protective role under salinity, particularly at moderate stress levels. Further research is needed to optimize Ca²⁺ use in saline agriculture and enhance sustainable cultivation of pomegranate in salt-affected soils. Full article

Saline–alkali land is a critical factor limiting agricultural production and ecological restoration. Utilizing salt-tolerant plants for bioremediation represents an environmentally friendly and sustainable approach to soil management. This study employed the highly salt-tolerant crop Portulaca oleracea L. cv. “Su Ma Chi Xian 3” as the test material. A plot experiment was established in coastal saline soils with planting P. a- oleracea (P) and no planting (CK) under three blocks with the different salt levels (S1: 2.16 g/kg; S2: 4.08 g/kg; S3: 5.43 g/kg) to systematically evaluate its salt accumulation capacity and effects on soil physicochemical properties. The results demonstrated that P. oleracea exhibited adaptability across all three salinity levels, with aboveground biomass following the trend PS2 > PS3 > PS1. The ash salt contents removed through harvesting were 1.29, 2.03, and 1.74 t/ha, respectively, in PS1, PS2, and PS3. Compared to no planting, a significant reduction in bulk density was observed in the 0–10 and 10–20 cm soil layers (p < 0.05). A significant increase in porosity by 9.72%, 16.29%, and 12.61% was found under PS1, PS2, and PS3, respectively, in the 0–10 cm soil layer. Soil salinity decreased by 34.20%, 50.23%, and 48.26%, in the 0–10 cm soil layer and by 14.43%, 32.30%, and 26.42% in the 10–20 cm soil layer under PS1, PS2, and PS3, respectively. The pH exhibited a significant reduction under the planting treatment in the 0–10 cm layer. A significant increase in organic matter content by 13.70%, 12.44%, and 13.55%, under PS1, PS2, and PS3, respectively, was observed in the 0–10 cm soil layer. The activities of invertase and urease were significantly enhanced in the 0–10 and 10–20 cm soil layers, and the activity of alkaline phosphatase also exhibited a significant increase in the 0–10 cm layer under the planting treatment. This study indicated that cultivating P. oleracea could effectively facilitate the improvement of coastal saline soils by optimizing soil structure, reducing salinity, increasing organic matter, and activating the soil enzyme system, thereby providing theoretical and technical foundations for ecological restoration and sustainable agricultural utilization of saline–alkali lands. Full article

The association between soil properties and zinc (Zn) availability, as well as how soil properties affect the Zn translocation from coastal soil to wheat grain, was not well understood. A pot study and field trial were conducted to examine the effects of soil properties and Zn application on grain yield and grain Zn concentration (Zn-conc) in wheat grown under coastal soils. Soil DTPA-Zn content positively correlated with concentrations of total Zn, total P, Olsen-P, and ammonia-N in soil. Zn-conc in aboveground plants negatively correlated with soil pH and Olsen-P. Total Zn accumulation (Zn-acc) in aboveground plants varied greatly among different soil treatments. Zn-acc positively correlated with soil DTPA-Zn content, Zn-conc in aboveground plants, aboveground biomass, and root weight. PLS-PM model analysis suggested that soil Zn supply and plant growth had direct effects on Zn utilization in wheat, while soil properties, soil nutrients, and soil available nutrients had indirect effects on Zn utilization in wheat by affecting soil Zn supply and/or plant growth. Grain yield and grain Zn-conc were increased by Zn application under low soil salinity, while Zn application under higher soil salinity did not increase grain Zn-conc. Soil Zn application increased both grain yield and grain Zn-conc of 20 wheat genotypes, while foliar Zn application further increased the average grain Zn-conc without an increase in grain yield. Adjusting the Zn supply tailored to suitable genotypes according to soil properties is promising to reach the Zn biofortification target and a satisfactory wheat grain yield under coastal saline soils. Full article

The Qinghai–Tibet Plateau, a critical ecological barrier and major livestock region, faces deteriorating grasslands and rising forage demand under its harsh alpine climate. Oat (Avena sativa L.), valued for its cold tolerance, rapid biomass accumulation, and ability to thrive in nutrient-poor soils, can expand winter feed reserves and partly alleviate grazing pressure on native rangelands. However, genetic improvement alone has not been sufficient to address the environmental challenges. This issue is particularly severe in the Qaidam Basin, where soil salinization, characterized by high pH, poor soil structure, and low nutrient availability, significantly limits crop performance. Rhizosphere growth-promoting bacteria (PGPR) are environmentally friendly biofertilizers known to enhance crop growth, yield, and soil quality, but their application in the saline soil of the Qaidam Basin remains limited. We evaluated two PGPR application rates (B1 = 75 kg hm⁻² and B2 = 150 kg hm⁻²) on ‘Qingtian No. 1’ oat, assessing plant growth, soil physicochemical properties, and rhizosphere microbial communities. The results indicated that both treatments significantly increased oat productivity, raised the comprehensive growth index, augmented soil organic matter, and lowered soil pH; B1 chiefly enhanced above-ground biomass and fungal community stability, whereas B2 more strongly promoted root development and bacterial community stability. Structural equation modeling showed that PGPR exerted direct effects on the comprehensive growth index and indirect effects through soil and microbial pathways, with soil properties contributing slightly more than microbial factors. Notably, rhizosphere organic matter, fungal β-diversity, and overall microbial community stability emerged as positive key drivers of the comprehensive growth index. These findings provide a theoretical basis for optimizing PGPR dosage in alpine forage systems and support the sustainable deployment of microbial fertilizers under saline soil conditions in the Qaidam Basin. Full article