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Liquid‐phase exfoliation, a technique for enhancing the properties of biochar, has been recognized as effective, circumventing the limitations of other methods such as high expenses, scalability, and complexity. This study explored the synergistic effect achieved by combining chicken feathers with elephant grass to create a composite feedstock for biochar production. The biochar was subjected to liquid‐phase exfoliation using acid and acetone. Elemental analysis indicated that the co‐carbonization of the combined biomass produced an enriched hybrid biochar. The oxygen content in both exfoliation routes (acid and acetone) increased, with an increase and decrease in carbon content in acetone and acid exfoliation, respectively. Textural analysis revealed significant enhancement, with surface areas of the acid‐exfoliated biochar more than twice the size of the hybrid biochar. The pore volume of both exfoliated samples was double that of the hybrid biochar. Microscopic surface examination revealed rougher, porous structures in the exfoliated biochars in comparison with the smooth, cohesive surface in hybrid biochar. Functional group analysis showed the presence of aromatic rings, a carbocyclic group, and an alkene, suggesting potential applications in adsorption. This study provides an efficient method for using liquid‐phase exfoliation to enhance biochar properties, benefiting industries reliant on biochar production and biomass utilization by improving product quality, sustainability, and environmental impact. [ABSTRACT FROM AUTHOR]

In semi-arid regions, production of good quality fodder is a challenge; cereal-legume intercropping can be a better alternative in improving forage yield and quality. The present study was conducted to assess the performance of feather Pennisetum (FP) in groundnut (GN) intercropping and for determining a sustainable forage cropping system. Therefore, an experiment was conducted with groundnut and feather Pennisetum as a monocrop and intercrop (2GN:1FP and 3GN:1FP), where FP was harvested at 60, 75, 90, and 120 days after sowing. The land equivalent ratio of intercropping was 15–29% higher indicating yield advantages and economic benefits over sole stands. Crude protein and fiber content was increased by 10 and 8% in intercropping, lignin content was reduced by 15% and neutral detergent fiber by 5% indicating the better quality of FP due to intercropping with GN. Intercropping of GN and FP increased the content of non-fibrous carbohydrate (13%), gas production (6.5%) and volatile fatty acids (6%) indicating better fodder digestibility. Furthermore, intercropping of GN and FP also increased the mineral content by 8-20% than sole stands. Apart from productivity, intercropping of FP and GN, improved water use efficiency over sole stand of both component crops. Considering, forage yield, quality and profitability, 3GN:1FP intercropping was superior and can be recommended as an alternative to monoculture. Our study concluded that in semi-arid regions double dual cropping of food and fodder can be achieved by intercropping which can provide opportunities to produce food and fodder simultaneously for livelihood, animal rearing and long-term sustainability. [ABSTRACT FROM AUTHOR]

Functional traits reflect plants' adaptability to their environment, and environmental gradients influence their distribution. But few studies have investigated the link between these traits and species substitution patterns or the relevant ecological factors. We measured the aboveground (leaf) and belowground (root) functional traits of Stipa species in 17 plots across natural grasslands in Ningxia in Northern China. Redundancy analysis was used to explore the relationships between Stipa's functional traits and its species substitution distribution. Then, on the species substitution gradient, principal component analysis (PCA) was used to verify and quantify the leaf economic spectrum (LES), root economic spectrum (RES), and whole‐plant economic spectrum (WPES), with the relation between these spectra investigated by fitting standardized major axis regressions. The effects of aboveground, belowground, and whole‐plant ecological factors were quantified and ranked by variance decomposition and hierarchical partitioning. Our results showed that functional traits drive the substitution distribution of Stipa species, in being variously coupled with its desert, typical, and meadow steppe habitat types. The leaf, root, and whole‐plant economic spectra of Stipa species in desert steppe exhibit a "quick investment‐acquisition" strategy. In typical steppe, the leaf and whole‐plant economic spectra of Stipa species correspond to a "fast investment‐acquisition" strategy, whereas the root economic spectrum adopts a "slow investment‐acquisition" strategy. On meadow steppe, the leaf, root, and whole‐plant economic spectra of Stipa species similarly adopt a "slow investment‐acquisition" strategy. Finally, when considering the environmental factors involved, we find that the substitution distribution of Stipa spp. is chiefly a response to shifting soil patterns, these mainly driven by soil total nitrogen and nitrogen/phosphorus ratio. Collectively, these findings provide an important reference for the ecological restoration and reconstruction of grassland ecosystems, to better understand the relationship between plant functional traits and ecological niche attributes, and thus guide the reasonable restoration of grassland vegetation. [ABSTRACT FROM AUTHOR]

Perennial ornamental grasses are often recommended for rain gardens, but few data support their use. We conducted two experiments to evaluate the ability of ornamental grass cultivars to grow while subjected to cyclical flooding, submergence, and drought typical of rain gardens. Our objectives were to determine the effects of cyclical flood and drought (Expt. 1) and submergence depth and duration (Expt. 2) on grass growth and survival. Seven cultivars were evaluated during greenhouse trials, including Pixie Fountain tufted hairgrass [Deschampsia cespitosa (L.) P. Beauv.], Northwind switchgrass (Panicum virgatum L.), Red October big bluestem (Andropogon gerardii Vitman), Purpurascens Chinese silvergrass (Miscanthus sinensis Andersson), Blue HeavenVR little bluestem [Schizachyrium scoparium (Michx.) Nash], Blonde Ambition blue grama grass [Bouteloua gracilis (Kunth) Lag. ex Griffiths], and Karl Foerster feather reed grass [Calamagrostis ×acutiflora (Schrad.) DC]. During Expt. 1, grasses underwent four cycles of flooding duration (2 days or 7 days) followed by drought (drying to volumetric soil water contents of 0.14 or 0.07 cm³·cm-3). During Expt. 2, grasses were cyclically submerged at 15 or 30 cm above the soil surface for 2, 4, or 7 days, followed by floodwater removal and drainage for 2 days before being resubmerged. Cyclical submergence continued until the 7-day submergence treatments completed four cycles. Both experiments were replicated in a full factorial randomized complete block design. Controls were included in both experiments. Plants were measured to determine plant height, shoot count, visual damage rating, shoot dry weight, and root dry weight. Floodwater chemistry and soil reducing conditions were measured during Expt. 2. Chinese silvergrass and switchgrass survived cyclical soil flooding/drought and submergence for 7 days at a depth of 30 cm while maintaining acceptable foliar damage. All grasses survived cyclical flood and drought when the soil volumetric water content was maintained at 14%, suggesting they can withstand periodic soil flooding as long as the water is not too deep. As water depth and duration increased from 4 days to 7 days, little bluestem, blue grama grass, and feather reed grass experienced significant foliar damage. Tufted hair grass and big bluestem experienced significant foliar damage when submerged for 2 days. Our results showed that perennial ornamental grasses can tolerate cyclical flood and drought and periodic submergence, but that plant conditions and survival vary, which can inform strategic plant placement within rain gardens, bioretention basins, and other stormwater management systems. [ABSTRACT FROM AUTHOR]

To precision calculate the speech transmission index (STI), it is necessary to know the level and spectrum of the interfering noise. Simplified design methods used in public address systems are limited to obtaining an appropriate signal-to-noise ratio based on A weighted sound levels. For this reason, among others, guidelines for designers usually contain information on typical interfering noise levels and do not provide information on the noise spectrum. As shown in the paper, the effect of the noise spectrum on STI can be very high, and when such spectrum cannot be obtained by measurement or computation, standardised spectra appropriate for a given type of noise can be used for STI calculations.

Knowledge of interfering noise is necessary for the correct design of a public address system. Noise sound levels can be obtained, for example, from BS 5389-1. It is more difficult to acquire knowledge of the interfering noise spectra, and the spectrum is also important for calculating speech intelligibility. As shown in the paper, for crowd noise, it is possible to determine the spectrum by pairing the level of noise to the speech spectrum for appropriate vocal effort. The error in determining the speech transmission index for public address systems for such selected noise spectra, relative to values for measurement-acquired noise spectra, is acceptable.

Stipa breviflora is a dominant species in the desert steppe of Northern China. Grazing is the main land use pattern of grassland, which could cause a variety of adaptive evolutionary mechanisms in plant community composition as well as individual plant growth and morphological characteristics. However, very little is known about the morphological structure and transcriptional regulation response to different grazing intensities in S. breviflora. In this study, transcriptome and anatomical analyses of S. breviflora under different grazing intensities, including no grazing, moderate grazing, and heavy grazing, were performed. The anatomical analysis results showed that epidermis cells and xylems significantly thicken with grazing intensity, suggesting that grazing results in increasing lignification. Furthermore, the components of cell walls such as lignin, cellulose, hemicellulose, and pectin were all increased dramatically and significantly under both moderate and heavy grazing. Transcriptome analysis showed that the differentially expressed genes related to different grazing intensities were also engaged in plant cell wall formation and in photosynthesis and respiration. In addition, the activities of ATP synthase and Rubisco-activating enzyme increased significantly with enhanced grazing intensity and differed significantly between moderate and heavy grazing intensities. The trends in transcriptome and plant phenotype changes are consistent. Taken together, these results indicated that S. breviflora has evolved a grazing tolerance strategy under long-term grazing conditions, influencing photosynthesis and respiration in terms of its own structure and enzyme activities in the body, to maintain normal life activities under different grazing conditions. [ABSTRACT FROM AUTHOR]

Predicting the future impact of climate change on Stipa tenacissima steppes is of paramount importance to prevent desertification. From this perspective, we selected seven populations, covering a rainfall range from 100 to 600 mm/year at the sites of seed collection, and we grew the seedlings at the same site. Gas exchange measurements of CO2, light response curves, chlorophyll content and isotopic analysis were investigated. Thala and Valencia populations displayed a contrasted gas exchange response. Both populations were subjected to A-Ci curve analysis. No significant difference was detected between these two different populations in the maximum rate of carboxylation (Vcmax) and the maximum rate of electron transport (Jmax). Stipa tenacissima exhibited a variable response in relation to different light intensities. Photosynthesis and chlorophyll fluorescence parameters proved to be significantly different among populations in response to light intensities. All populations exhibited similar chlorophyll content. The isotopic analysis highlighted a different carbon and nitrogen isotopic composition (δ13C and δ15N) and carbon content © among populations. Mesic populations presented a higher gas exchange activity and light response. The xeric populations performed a photosynthesis adjustment along with minimizing chlorophyll content. Under climate change, S. tenacissima limits productivity, which may lead to desertification. [ABSTRACT FROM AUTHOR]

The purpose of this experiment was to explore the monthly dynamic changes of yield and nutrient components of temperate desert-steppe type rangeland and temperate steppe-desert type rangeland on the northern slope of Tianshan Mountains in Xinjiang, and the effects of grazing on the weight changes of multiple Suffolk ewes and weaned lambs under the conditions of two grassland types. Suffolk postpartum ewes with a similar weight of two years old and 120 lambs after weaning were randomly divided into two groups. Each group had three repetitions, and each repetition had 20 sheep. Group A lambs and Group C ewes were grazed in temperate desert-steppe type rangeland experimental area (type I grass group, namely Festucasulcata, feather grass and Seriphidium kaschgaricum), while Group B lambs and Group D ewes were grazed in temperate steppe-desert type rangeland experimental area (type II grass group, namely Seriphidium borotalense Ling et Y. R. Ling, Kochia prostrata and Carex turkestanica). The trial period was 120 days. The results showed that in June and September, the fresh grass yield of type I grass group was significantly higher than that of type II grass group (P<0.05). In September, the hay yield of type I grass group was significantly higher than that of type II grass group (P<0.05). In June, the dry-fresh ratio of type I grass group was significantly lower than that of type II grass group (P<0.05). In June and September, the crude ash content of type I grass group was significantly lower than that of type II grass group ( P<0.05). In July, the crude protein content of type I grass group was significantly higher than that of type II grass group (P<0.05), and in September, the crude protein content of type I grass group was significantly lower than that of type II grass group (P<0.05). The content of nitrogen-free extracts of type I grass group in June was significantly higher than that in September (P<0.05). In June, July and September, the phosphorus content of type II grass group was significantly higher than that of type I grass group (P<0.05). There was no significant difference in total weight gain, average daily weight gain, and relative weight gain between the two grazing grassland types (P>0.05). The weaned lamb weight increased continuously, and the litter size, litter weight, and weaned weight of ewes in the following year had no significant difference (P>0.05). The results showed that with the increase of temperature and the decrease of precipitation, the forage yield of the two grazing grassland types decreased first and then increased, and the forage nutrition level decreased. The grazing adaptability and stress resistance of multiple Suffolk sheep were better under extreme environmental conditions. [ABSTRACT FROM AUTHOR]

Homogeneous esterification of cellulose isolated from Stipatenacissima plant located in the eastern region of Morocco, using anhydride and acid chloride compounds has been performed in ionic liquids (ILs) prepared in our laboratory as reaction mediums. ILs were chosen as solvents due to their green character and ability to disperse native cellulose compared to other solvents. [C4mim]OAc showed the highest solubility percentage of cellulose (15 wt%). Other principles of green chemistry were applied herein such as the uses of biomass, catalysts, and green solvents. The formed cellulosic esters were analyzed for structural, surface, and thermal properties by various analytical techniques: FTIR-ATR, NMR, XRD, TGA, and DSC. The esterificating agents were varied in this study to obtain different cellulose derivatives. Notably, high degrees of substitution (DS) were achieved for cellulose propionate (2.91) and cellulose butyrate (2.76). However, cellulose phthalate and cellulose laureate were obtained with low DS values, which affect their solubility in different solvents depending on their DS values. The effect of esterification on cellulose properties, on one hand, decreases the crystallinity index (CIr) and crystallite size, however, on the other hand, increased the surface area and pore volume. The contact angle measurements revealed an enhancement in the hydrophobicity of the cellulose esters. Particularly, cellulose propionate with high DS exhibited a significantly elevated contact angle, reaching 142.5°. This emphasizes that the hydrophobic nature of the modified cellulose can be improved by raising the DS, rather than solely relying on the length of the carbonyl chain. [ABSTRACT FROM AUTHOR]

The subject of this study was to understand how grazing and precipitation affect the carbon cycle of grassland ecosystem. The experiment was carried out in a desert steppe of Siziwang Banner, Inner Mongolia, China, and measured CO2 flux and abiotic factors twice a month during the growing season (July to October in 2016, May to October in 2017). The experiment used a completely randomized block design, involving four different stocking rate treatments [CK, no grazing, (0 sheep unit hm –2 half year–1), light stocking rate (LG, 0.93 sheep unit hm–2 half year–1), moderate stocking rate (MG, 1.82 sheep unit hm–2 half year–1) and heavy stocking rate (HG, 2.71 sheep unit hm–2 half year–1)] with three replicates, and four precipitation treatments [50% reduced precipitation (P1), natural precipitation (P2), 50% increased precipitation (P3) and 100% increased precipitation (P4)] were set up in each stocking rate treatment plot. Results indicated that increased precipitation treatments significantly increased soil water content (SWC) and soil respiration (Rs), and significantly reduced soil temperature (Ts), grazing treatments significantly reduced Ts, the interaction between precipitation and stocking rate had no significant impact on the above indicators; Rs increased with increasing precipitation in the order: P4 > P3 > P2 > P1, Rs exhibited the following order under different stocking rates: CK > LG > MG > HG. There was a strong positive correlation between Rs and SWC, and a negative relationship between Rs and Ts. Our results demonstrate that SWC is the dominant factor affecting Rs, as SWC explained 87.12% of the variation in Rs. [ABSTRACT FROM AUTHOR]

Styrene–butadiene rubber (SBR) composites reinforced with two different local Libyan grasses; Stipa tenacissima (locally known as Halfa) and Stipagrostis pungens (locally known as Esbat); were prepared. The effect of filler type and content (10, 20, 30 and 40 wt%) on the mechanical properties of the composites including stress at break, elongation at break, impact strength and microhardness were evaluated. The results illustrated that the stress at break of SBR increased with the addition of 20% and 30% of Halfa or Esbat. In addition, the results revealed that the highest values of stress at break were obtained by composites with 20% filler content. Composites made with Halfa showed higher stress at break than composites made with Esbat. The incorporation of Halfa and Esbat into SBR caused a significant decrease in the elongation at break. The elongation at break of the composites made with Halfa was slightly higher than that of composites made with Esbat. In both types of composites, the impact strength was increased with increasing the filler content up to 30%, and then decreased. Composites made with Esbat showed marginally better impact strength than did composites made with Halfa. The incorporation of Halfa and Esbat caused an increase in the hardness properties in comparison to pure SBR. In the all composite compositions, Halfa composites had higher hardness values than Esbat composites. The optical microscope results of SBR composites were in good agreement with the mechanical properties results. The formation of filler aggregation was observed in SBR composites with 10% and 40% Halfa and Esbat. On the other hand, no filler aggregation was observed in the optical images of SBR composites with 20% and 30% Halfa and Esbat. In brief, these grasses can be used as effective filler for reinforcing polymers to develop low density composites with improved properties. [ABSTRACT FROM AUTHOR]

Abstract Functional traits reflect plants' adaptability to their environment, and environmental gradients influence their distribution. But few studies have investigated the link between these traits and species substitution patterns or the relevant ecological factors. We measured the aboveground (leaf) and belowground (root) functional traits of Stipa species in 17 plots across natural grasslands in Ningxia in Northern China. Redundancy analysis was used to explore the relationships between Stipa's functional traits and its species substitution distribution. Then, on the species substitution gradient, principal component analysis (PCA) was used to verify and quantify the leaf economic spectrum (LES), root economic spectrum (RES), and whole‐plant economic spectrum (WPES), with the relation between these spectra investigated by fitting standardized major axis regressions. The effects of aboveground, belowground, and whole‐plant ecological factors were quantified and ranked by variance decomposition and hierarchical partitioning. Our results showed that functional traits drive the substitution distribution of Stipa species, in being variously coupled with its desert, typical, and meadow steppe habitat types. The leaf, root, and whole‐plant economic spectra of Stipa species in desert steppe exhibit a “quick investment‐acquisition” strategy. In typical steppe, the leaf and whole‐plant economic spectra of Stipa species correspond to a “fast investment‐acquisition” strategy, whereas the root economic spectrum adopts a “slow investment‐acquisition” strategy. On meadow steppe, the leaf, root, and whole‐plant economic spectra of Stipa species similarly adopt a “slow investment‐acquisition” strategy. Finally, when considering the environmental factors involved, we find that the substitution distribution of Stipa spp. is chiefly a response to shifting soil patterns, these mainly driven by soil total nitrogen and nitrogen/phosphorus ratio. Collectively, these findings provide an important reference for the ecological restoration and reconstruction of grassland ecosystems, to better understand the relationship between plant functional traits and ecological niche attributes, and thus guide the reasonable restoration of grassland vegetation.

This study used alfa grass fibres as a natural low-cost adsorbent to remove lead, copper, and zinc ions from aqueous solutions. The adsorbent was characterized by FTIR, SEM, BET surface area, ATG, and XRD techniques. The effects of pH, contact time, initial metal concentration, and adsorbent dosage on the adsorption efficiency were evaluated in batch experiments. The results showed that the adsorption of all metals was fast, and optimal removal efficiency was achieved within 25 min of contact time using 5000 mg/L of Alfa fibres at pH 6.3. The adsorption selectivity order was Pb2+ > Cu2+ > Zn2+ with Pb2+ removal efficiencies up to 97.6%. The adsorption kinetics were best explained by a pseudo-second-order kinetic model. The experimental adsorption data fitted very well with the Langmuir isotherm model, and less well with the Freundlich and Temkin isotherm models. The maximum adsorption capacities were respectively 14.492, 11.904, and 8.695 mg/g for Pb2+, Cu2+, and Zn2+. The results of this study indicated that Alfa fibres could be used as effective adsorbent for the removal of Pb2+, Cu2+, and Zn2+ from aqueous solutions. [ABSTRACT FROM AUTHOR]

In grassland ecosystems, the decomposition of litter serves as a vital conduit for nutrient transfer between plants and soil. The aim of this study was to depict the dynamic process of grass litter decomposition and explore its major driver. Three typical grasses [Stipa bungeana Trin (St. B), Artemisia sacrorun Ledeb (Ar. S), and Thymus mongolicus Ronniger (Th. M)] were selected for long-term litter decomposition. Experiments were conducted using three single litters, namely, St. B, Ar. S, and Th. M, and four different compositions of mixed litter: ML1 (55% St. B and 45% Th. M), ML2 (55% St. B and 45% Ar. S), ML3 (75% St. B and 25% Th. M), and ML4 (75% St. B and 25% Ar. S). The dynamic patterns of mass and microelements (Ca, Mg, Fe, Mn, Cu, and Zn) within different litter groups were analyzed. Our findings indicated that, after 1035 days of decomposition, the proportion of residual mass for the single litters was as follows: Th. M (60.6%) > St. B (47.3%) > Ar. S (44.3%), and for the mixed groups it was ML1 (48.0%) > ML3 (41.6%) > ML2 (40.9) > ML4 (38.4%). Mixed cultivation of the different litter groups accelerated the decomposition process, indicating that the mixture of litters had a synergistic effect on litter decomposition. The microelements of the litter exhibited an initial short-term increase followed by long-term decay. After 1035 days of decomposition, the microelements released from the litter were, in descending order, Mg > Ca > Fe > Cu > Mn > Zn. Compared to the separately decomposed St. B litter, mixing led to an inhibition of the release of Ca (antagonistic effect), while it promoted the release of Mg, Cu, and Zn (synergistic effect). For the single litter, the stepwise regression analysis showed that Ca was the dominant factor determining early litter decomposition. Mg, Mn, and Cu were the dominant factors regulating later litter decomposition. For the mixed litter groups, Ca, Mn, and Mg were the dominant factors closely related to early decomposition, and TN emerged as a key factor regulating the mass loss of mixtures during later decomposition. In summary, nitrogen and microelements co-drive the decomposition of typical grass litter. Our study underscores that, in the succession process of grassland, the presence of multiple co-existing species led to a faster loss of plant-derived materials (litter mass and internal elements), which was primarily modulated by species identity and uniformity. [ABSTRACT FROM AUTHOR]

Revealing the water use pattern of plants influenced by coal-mining-caused land subsidence is crucial to understand plant–water interactions and guide ecological restoration. However, available information on herbaceous plants, the dominant species in most arid and semi-arid regions with abundant coal resources, remains inadequate. We investigated the water use patterns of Stipa bungeana Trin. by measuring soil water content, root distribution, and stable isotopes of hydrogen (δ2H) and oxygen (δ18O) of soil water and plant stem water both before and after a rainfall event. The results revealed that prior to rainfall, both areas exhibited a low soil water content with no discernible difference in soil drought. However, the soil waters δ2H and δ18O were found to be more enriched at varying depths within the subsidence area, indicating a heightened level of soil evaporation. Both soil water content and soil water isotopic composition responded sensitively to rainfall, with rainfall primarily replenishing the shallow layer (0–20 cm), thereby reflecting an infiltration mode dominated by piston flow. More water seeped into deeper soil layers in the subsidence area compared to the non-subsidence area, with more preferential flow. Before rainfall, the sources of plant water uptake were consistent both at shallow and deep soil layers, implying that the proportion of water uptake gradually decreased with increasing depth. After rainfall, the sources of plant water uptake differed slightly between the two soil layers. The plants in non-subsidence and subsidence areas dominantly extracted soil water at depths greater than 10 cm and 20 cm, respectively. The root system in the subsidence area was more developed than that in the non-subsidence area. Plant water uptake was primarily influenced by the spatial distribution of roots, as well as the post-rainfall water distribution, regardless of whether they were in the subsidence area or not. Although land subsidence affected soil water transport, the water uptake pattern of Stipa bungeana Trin. was similar before and after rainfall, indicating the adaptive growth of plants through their roots in the subsidence area. The high adaptability of herbs such as Stipa bungeana Trin. makes them a viable option for vegetation restoration in subsidence areas. This study has significant implications for evaluating plant–water relationships in subsidence areas due to coal mining, thereby providing a fundamental basis and valuable reference for ecological restoration and management strategies within such affected regions. [ABSTRACT FROM AUTHOR]

Background: Long‐term overgrazing has led to severe degradation of grasslands, posing a significant threat to the sustainable use of grassland resources. Methods: Based on the investigation of changes in functional traits and photosynthetic physiology of Stipa breviflora under no grazing, moderate grazing, and heavy grazing treatments, the changes in expression patterns of genes and proteins associated with different grazing intensities were assessed through integrative transcriptomic and proteomic analyses. Results: Differentially expressed genes and proteins were identified under different grazing intensities. They were mainly related to RNA processing, carbon metabolism, and secondary metabolite biosynthesis. These findings suggest that long‐term grazing leads to molecular phenotypic plasticity, affecting various biological processes and metabolic pathways in S. breviflora. Correlation analysis revealed low correlation between the transcriptome and the proteome, indicating a large‐scale regulation of gene expression at the posttranscriptional and translational levels during the response of S. breviflora to grazing. The expression profiles of key genes and proteins involved in photosynthesis and phenylpropanoid metabolism pathways suggested their synergistic response to grazing in S. breviflora. Conclusions: Our study provides insight into the adaptation mechanisms of S. breviflora to grazing and provides a scientific basis for the development of more efficient grassland protection and utilization practices. [ABSTRACT FROM AUTHOR]

Stipa is a genus comprising ca. 150 species found in warm temperate regions of the Old World and around 30% of its representatives are of hybrid origin. In this study, using integrative taxonomy approach, we tested the hypothesis that hybridization and introgression are the explanations of the morphological intermediacy in species belonging to Stipa sect. Smirnovia, one of the species-rich sections in the mountains of Central Asia. Two novel nothospecies, S. magnifica × S. caucasica subsp. nikolai and S. lingua × S. caucasica subsp. nikolai, were identified based on a combination of morphological characters and SNPs markers. SNPs marker revealed that all S. lingua × S. caucasica samples were F1 hybrids, whereas most of S. magnifica × S. caucasica samples were backcross hybrids. Furthermore, the above mentioned hybrids exhibit transgressive morphological characters to each of their parental species. These findings have implications for understanding the process of hybridization in the genus Stipa, particularly in the sect. Smirnovia. As a taxonomic conclusion, we describe the two new nothospecies S. × muksuensis (from Tajikistan) and S. × ochyrae (from Kyrgyzstan) and present an identification key to species morphologically similar to the taxa mentioned above. [ABSTRACT FROM AUTHOR]

Elevated atmospheric CO2 concentration and precipitation change affect plants' survival and thriving. Phenotypic plasticity can show plants adaptability to varying environment. Physiological plasticity reflects plants capacity to open areas, and morphological plasticity reflects capacity to survive and grow. In this study, we simulated combined effects of elevated CO2 and precipitation change on the phenotypic plasticity of two Stipa species: Stipa grandis and Stipa breviflora. Our results indicated that plasticity of physiology was higher than plasticity of morphology under either ambient or elevated CO2 concentration in both Stipa species. S. breviflora showed higher plasticity index of physiological (PIp) and plasticity index of morphological (PIm) than S. grandis under elevated CO2 concentration. Therefore, we speculate that S. breviflora is more adaptable than S. grandis under high CO2 concentration in the future. Elevated atmospheric CO2 concentration and simultaneous precipitation change is advantageous to S. breviflora distribution expansion, nonetheless, the changing environments also favor the competitive ability of S. grandis. [ABSTRACT FROM AUTHOR]

The degradation and desertification of grassland ecosystems have garnered significant attention both domestically and internationally. Grassland restoration techniques are widely considered a principal measure to promote the sustainable utilization of grasslands, with soil nutrient content being a core indicator for assessing the effectiveness of restoration in degraded grasslands. This study aims to explore the differential impacts of various grassland restoration methods on soil nutrient distribution in degraded Stipa grandis grasslands. Three major restoration methods, i.e., root cutting, enclosure, and fertilization, were applied in the study area. The soil nutrient content was measured and analyzed under the different restoration methods and at varying depths. The results revealed that under all three restoration methods and at different soil depths (0–10 cm, 10–20 cm, 20–30 cm), the organic matter, total nitrogen, total phosphorus, alkali-hydrolyzable nitrogen, alkali-hydrolyzable phosphorus, and available potassium contents were significantly higher than those in the control group (p < 0.05). Furthermore, as soil depth increased, the contents of organic matter and all nutrients gradually decreased. Specifically, regarding the contents of different nutrients, the order of organic matter, total nitrogen, total phosphorus, alkali-hydrolyzable nitrogen, and available phosphorus was as follows: fertilization > enclosure > root cutting > control, while the contents of total potassium and available potassium followed the sequence: fertilization > enclosure > control > root cutting. Additionally, based on the canonical correlation analysis (R2 = 0.88), the total phosphorus content in soil had the greatest impact on soil nutrients, while vegetation cover and plant height contributed the most to vegetation characteristics. In grassland restoration, the increase in soil total phosphorus led to higher vegetation cover and height, mildly influenced plant diversity and density, and simultaneously promoted biomass accumulation. These research findings provide a solid theoretical foundation for the application of grassland restoration techniques, contributing to the sustainable development of grassland ecosystems. [ABSTRACT FROM AUTHOR]

Estimation of the cytogenetic effects in the populations of dwarf feather grass was carried out at 63 points of the site "4A" of the Semipalatinsk Test Site (Kazakhstan) that do not differ in soil characteristics and contamination with heavy metals, but contrast in the level of radioactive contamination. In the years 1953–1957, military radioactive substances were tested at the site "4A." The dose loads on dwarf feather grass plants at this site vary in the range of 0.00036–11 Gy/growing season, and internal radiation from 90Sr makes the main contribution to the dose absorbed by plants. It was demonstrated that the dependence of the frequency of cytogenetic effects on the dose logarithm is divided into two sections. In the range of 0.36–162 mGy, the frequency of aberrant cells does not differ statistically significantly from the control level. An increase in the dose above this limit leads to a statistically significant increase in the frequency of aberrant cells. The inflection points were also estimated for other cytogenetic parameters (120 mGy for single fragments and bridges, 141 mGy for double fragments and bridges, and 174 mGy for mitotic abnormalities). Double bridges make the main contribution to the formation of cytogenetic effects, which is additional evidence of the radiation nature of changes observed in dwarf feather grass populations. [ABSTRACT FROM AUTHOR]

Nassella neesiana (Chilean needle grass), an invasive 'sleeper weed' established in sheep and beef pastures in three of New Zealand's sixteen local government regions, has a potential geographic range amounting to 3.96 million hectares spanning all regions except the West Coast. It impacts the productivity, market value and welfare of livestock through its sharp penetrating that cause blindness and the downgrading of wool, hides, and carcasses. In this study we estimate the benefit of preventing its spread as the present value (PV) of local (regional) and national productivity losses that would accrue over 200 years under a 'do nothing' spread scenario. Using a 3% discount rate and two assumed spread rates, 201 and 100 years to 90% occupation of its potential range, we calculate national PV losses of NZ$ 192 million and NZ$ 1,160 million respectively. In a breakeven analysis, these losses, which equate to the national benefits of preventing the spread, justify annual expenditures of NZ$ 5.3 million and NZ$ 34 million respectively. Restricting the analyses to the regions with known infestations (Hawke's Bay, Marlborough, Canterbury) provided much lower estimates of the benefits (ranging from NZ$ 16.8 million to NZ$ 158 million) because spillover benefits from preventing spread to the other susceptible regions are not accounted for. These analyses support a nationally coordinated approach to managing N. neesiana in New Zealand involving surveillance and control measures respectively in the susceptible and infested regions. [ABSTRACT FROM AUTHOR]

Labor consumption of phytomass measurements on sample plots hinders the extrapolation of point data to areas comparable to commercial lands or landscape units. Vegetation indices calculated from satellite images are usually considered indicators of green phytomass; they are used for its areal estimates. The task of this study is to establish the informativity of the normalized differential vegetation index (NDVI) depending on the fractional structure of living and dead aboveground phytomass, seasonal dynamics of the biological cycle, hydrothermal conditions, and landscape position. The results of monthly measurements of aboveground phytomass fractions on 13 sites in phytocenoses of forest feather grass and feather grass formations in the Burtinskaya steppe (Orenburg Nature Reserve) from May to September 2015–2020 were used. The NDVI values were calculated for each period from Landsat satellite images at all sites. Hypotheses about geobotanical, hydrothermal, phonological, and landscape factors of NDVI informativity were tested by calculating the Spearman correlation coefficients using the dispersion and multiregression analysis. The discrepancy between the seasonal peaks of the NDVI and green phytomass is not consistent with the common concept of a direct indicator value of the NDVI. The total live biomass correlates more clearly with the index in June and July; the correlation is lower in the end of the season. The NDVI index turned out to be sensitive not so much to the reserves of green phytomass, but more to the mass and proportion of forbs and the ratio of live and dead phytomass. In late spring and early summer, the NDVI is most closely associated with forbs and, in July, with cereals. The hypothesis about the possibility of screening green mass with standing dead biomass was confirmed, which leads to a decrease in the NDVI despite the preservation or growth of green phytomass. The NDVI may underestimate the real green phytomass if there is a sharp increase in the mass of standing dead biomass, usually in the second half of summer and early autumn. The NDVI more adequately reflects the state of the aboveground phytomass of steppe communities that have not been exposed to fires for a long time when compared with burned communities and fallows. [ABSTRACT FROM AUTHOR]

Phylogenetic analysis provides crucial insights into the evolutionary relationships and diversification patterns within specific taxonomic groups. In this study, we aimed to identify the phylogenetic relationships and explore the evolutionary history of Stipa using transcriptomic data. Samples of 12 Stipa species were collected from the Qinghai-Tibet Plateau and Mongolian Plateau, where they are widely distributed, and transcriptome sequencing was performed using their fresh spikelet tissues. Using bidirectional best BLAST analysis, we identified two sets of one-to-one orthologous genes shared between Brachypodium distachyon and the 12 Stipa species (9397 and 2300 sequences, respectively), as well as 62 single-copy orthologous genes. Concatenation methods were used to construct a robust phylogenetic tree for Stipa, and molecular dating was used to estimate divergence times. Our results indicated that Stipa originated during the Pliocene. In approximately 0.8 million years, it diverged into two major clades each consisting of native species from the Mongolian Plateau and the QinghaiTibet Plateau, respectively. The evolution of Stipa was closely associated with the development of northern grassland landscapes. Important external factors such as global cooling during the Pleistocene, changes in monsoonal circulation, and tectonic movements contributed to the diversification of Stipa. This study provided a highly supported phylogenetic framework for understanding the evolution of the Stipa genus in China and insights into its diversification patterns. [ABSTRACT FROM AUTHOR]

The intensification of pasture degradation in the southern part of European Russia, which is caused by unfavorable hydrothermal conditions and unregulated livestock numbers, requires the development of approaches to assess the capacity of forage lands using Earth remote sensing methods. The spectral reflectance properties of vegetation are determined by its taxonomic, structural, phenological, biophysical, and biochemical characteristics. However, the patterns of how these parameters affect the spectral response are region-specific and heavily influenced by soil cover. Therefore, it is essential to expand the regional scope of studies on the spectral reflectance properties of various vegetation types. This research is devoted to determining the spectral reflectance properties of natural zonal pastures in southern European Russia, based on geobotanical investigations and field spectrometry using the PSR-1100f instrument within the 320–1100 nm range. Groundwork was carried out in May (the period of maximum green mass of vegetation) 2020–2022 in the territories of natural zonal pastures in Astrakhan and Volgograd oblasts, Stavropol krai, and the Republics of Dagestan and Kalmykia. Significant differences were found between feather grasses, semishrubs, and annuals in the visible and near-ultraviolet spectral regions. Changes in the projective cover, under other equal conditions, have the most significant impact on spectral properties in the 660–670 nm range, which is consistent with the results of other researchers. Vegetation indices were identified that are best suited for determining projective cover and above-ground biomass of pastures with various dominant species. Further research will enable transitioning from point measurements of spectral reflectance and structural vegetation characteristics to satellite data with different spatial resolutions. [ABSTRACT FROM AUTHOR]

Cryopreservation is one way to preserve rare, endangered species. However, during the cryopreservation process, plant cells undergo considerable stress, which may lead to cell death. In our work, orthodox Stipa seeds of six rare species were cryopreserved: S. sareptana, S. ucrainica, S. tirsa, S. dasyphylla, S. adoxa, and S. pulcherríma. Short-term cryopreservation (14 days) stimulated germination of all Stipa species studied. Prolonged cryopreservation (70 days and more) decreased the germination of all Stipa seeds except S. sareptana. The decrease in germination progressed over time as a result of the cumulative stress of cryopreservation rather than the initial stress. To stimulate germination, seeds were stratified and treated with GA3, KNO3, NaOH, and H2O2. After four years of seed cryopreservation, it was possible to obtain seedlings of all the Stipa species studied with 30 days of stratification and 180 days of germination. After five years of cryopreservation and seed treatment with 30% NaOH for one hour, the best germination was obtained in S. adoxa and S. pulcherrima. After treatment with 5% H2O2 for 20 min, the best germination was obtained in S. sareptana, S. ucrainica, and S. dasyphylla. S. sareptana seeds germinated in all the aforementioned experiments. S. sareptana has a non-deep physiological dormancy and is the most widespread and drought-tolerant Stipa species studied. The best habitat adaptation and stress tolerance correlated with this species'cryotolerance. S. sareptana was recommended for further cryopreservation, while storage protocols for the other Stipa species studied need further improvements. [ABSTRACT FROM AUTHOR]

Due to climate change and global warming, the frequency of sandstorms in northern China is increasing. Stipa breviflora, a dominant species in Eurasian grasslands, can help prevent desertification from becoming more serious. Studies on S. breviflora cover a wide range of fields. To the best of our knowledge, the present study is the first to sequence, assemble, and annotate the S. breviflora genome. In total, 2,781,544 contigs were assembled, and 2,600,873 scaffolds were obtained, resulting in a total length of 649,849,683 bp. The number of scaffolds greater than 1 kb was 70,770. We annotated the assembled genome (>121 kb), conducted a selective sweep analysis, and ultimately succeeded in assembling the Matk gene of S. breviflora. More importantly, our research identified 26 scaffolds that may be responsible for the drought tolerance of S. breviflora Griseb. In summary, the data obtained regarding S. breviflora will be of great significance for future research. [ABSTRACT FROM AUTHOR]

Epichloë endophytes not only affect the growth and resistance of their host plants but also confer nutrient benefits to parasitized hosts. In this study, we used Pedicularis kansuensis to parasitize Stipa purpurea, both with and without endophytic fungi, and to establish a parasitic system. In this study, endophytic fungal infection was found to increase the dry weight of the leaf, stem, and leaf sheath, as well as the plant height, root length, tiller number, aboveground biomass, and underground biomass of S. purpurea under root hemiparasitic stress. Meanwhile, the 13C allocation of the leaf sheaths and roots of S. purpurea increased as the density of P. kansuensis increased, while the 13C allocation of the leaf sheaths and roots of E+ S. purpurea was lower than that of E− S. purpurea. The 13C allocation of the stem, leaf sheath, and root of E+ S. purpurea was higher than that of its E− counterpart. Furthermore, the content of photosynthetic 13C and the 13C partition rate of the stems, leaves, roots, and entire plant of S. purpurea and P. kansuensis transferred from S. purpurea increased as the density of P. kansuensis increased. These results will generate new insights into the potential role of symbiotic microorganisms in regulating the interaction between root hemiparasites and their hosts. [ABSTRACT FROM AUTHOR]

Background: Clonal plants can successfully adapt to various ecosystems. A trade-off between sexual and clonal reproduction is generally assumed in clonal plants, which may be influenced both by the characteristics of the plant itself and environmental conditions. Currently, it is unclear how climate change, and specifically warming and increased precipitation, might affect sexual and clonal reproduction in clonal plants. Therefore, this study aimed to investigate both the sexual and clonal reproduction responses of Stipa breviflora to warming and increased precipitation. A controlled experiment was conducted by inducing increases in precipitation (ambient condition, 25% and 50% increases) and warming (ambient temperature, 1.5 °C and 3.0 °C increases). Results: Warming significantly influenced both the ratio of reproductive ramet shoot biomass to total shoot biomass, and the ratio of reproductive ramet number to total ramet number. Additionally, the ratio of reproductive ramet shoot biomass to total shoot biomass was also significantly affected by increased precipitation. Increased precipitation benefited sexual reproduction, while effects of warming on reproductive and/or vegetative ramets varied from negative to positive depending on precipitation conditions. There was no relationship between the number or shoot biomass of reproductive ramets and vegetative ramets. Reproductive ramets displayed greater sensitivity to climate change than vegetative ramets. Conclusions: The findings of our study suggest that there was no trade-off between sexual and clonal reproduction in S. breviflora. The combined impact of warming and increased precipitation promoted sexual reproduction but did not inhibit clonal reproduction. Clonal plants with the capacity for both sexual and clonal reproduction, may cope with climate change well via clonal reproduction, ensuring their survival. [ABSTRACT FROM AUTHOR]

Cleistogenes songorica, as a clustered grass, is the main grassland flora of the Stipa breviflora desert grassland. Some studies have shown that the constructive species of S. breviflora (sparse cluster type) is prone to cluster fragmentation; however, research on C. songorica is relatively rare. Then will the C. songorica plant population (dense cluster type) also have cluster fragmentation under the influence of intense grazing? To answer this question, we used variance analysis and geo‐statistical methods. The spatial distribution of C. songorica in S. breviflora desert steppe in Inner Mongolia was measured under four grazing intensities (no grazing, CK, 0 sheep·ha−1·half year−1; light grazing, LG, 0.93 sheep·ha−1·half year−1; moderate grazing, MG, 1.82 sheep·ha−1·half year−1; and heavy grazing, HG, 2.71 sheep·ha−1·half year−1) and four scales (10 cm × 10 cm, 20 cm × 20 cm, 25 cm × 25 cm, 50 cm × 50 cm). We then analyzed C. songorica whether fragmentation was present. The results showed that increased grazing intensity is associated with increased density and decreased height, coverage, and standing crop of C. songorica. The spatial distribution of C. songorica was affected by structural factors, and spatial heterogeneity decreased with increased spatial scale. With increased grazing intensity and spatial scale, the patch area of C. songorica gradually increased and tended toward band distribution. In summary, increased grazing intensity and spatial scale led to weakened heterogeneity of C. songorica spatial distribution and increased consistency. [ABSTRACT FROM AUTHOR]

Dominant species play a principal role in controlling and maintaining ecosystem stability. Stipa breviflora is the dominant species in desert steppe. Changes in the stability of a plant population will further affect the stability of the broader habitat, such as the desert steppe. In the desert steppe ecosystem, it is not clear what level of grazing intensity is best for improving the grazing tolerance and stability of the vegetation. And, the study of this question should involve a multi-dimensional, comprehensive analysis. This study will utilize variance analysis, plant population stability, and trade-off index to study S. breviflora, the dominant species in the desert steppe in Inner Mongolia, and its performance under four grazing intensities (control, CK, 0 sheep·ha−1·half year−1; light grazing, LG, 0.93 sheep·ha−1·half year−1; moderate grazing, MG, 1.82 sheep·ha−1·half year−1; and heavy grazing, HG, 2.71 sheep·ha−1·half year−1) over six scales (5 cm × 5 cm; 10 cm × 10 cm; 20 cm × 20 cm; 25 cm × 25 cm; 50 cm × 50 cm; and 100 cm × 100 cm). The characteristics of the population stability of S. breviflora were explored. The results showed that the response of S. breviflora's stability to heavy grazing was multidimensional. Heavy grazing reduced the population stability of S. breviflora. Across different dimensions, base coverage was the first of the population stability metrics of S. breviflora to destabilize, followed by projection coverage, density, and height. Heavy grazing also affected the trade-offs of S. breviflora's population stability across different dimensions. In general, the trade-off degree decreased as the grazing intensity increased, and it increased as the scale increased. [ABSTRACT FROM AUTHOR]

The present investigation was carried out in the Department of Vegetable Science, Dr. YS Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh, India during kharif, May, 2020-January, 2021 to examine the effect of different mulches and bed sizes on the growth, yield and quality of turmeric. The trial was laid out in randomized complete block design (factorial) with 9 treatment combinations, including 3 mulches (silver-black mulching film, pine needles and dry grass) with 3-bed sizes (9×1 m², 6×1 m² and 3×1 m²), which were triplicated. Turmeric yield proved to be significantly affected by mulching materials with silver-black mulching film producing the highest yield (32.01 t ha-1) whereas pine needles produced the lowest yield (23.85 t ha-1). Rhizome length and breadth, the number of primary and secondary rhizomes, dry recovery, essential oil, oleoresin and curcumin content were some of the yield and quality characteristics that have been improved by the use of silver-black mulching film. Bed size also provided a significant effect on the yield of turmeric with the highest (29.03 t ha-1) in bed size 9×1 m² whereas lowest in 3×1 m² (25.75 t ha-1). A combination of silver-black mulching film and 9×1 m² bed size provided the significantly highest turmeric yield (33.56 t ha-1). This study recommends that farmers in Himachal Pradesh's mid-hill zone to produce turmeric using silver-black mulching film on beds measuring 9×1 m² for better growth, yield and improved quality of turmeric. [ABSTRACT FROM AUTHOR]

Nowadays, with regard to many environmental problems, the development of environmentally friendly materials such as natural fiber composites is a real alternative to synthetic fibers. They have many interesting advantages such as their availability, their low cost, their low density, their biodegradable character, their specific resistance properties and their low impact on the environment. The present paper is aimed at fabricating and machining of an epoxy composite material reinforced with Alfa (Stipa tenacissima L.) fibers. The full factorial analysis was used to assess the effect of cutting parameters such as cutting velocity and feed rate on the arithmetic roughness Ra of machined surfaces obtained by down milling and up milling operations. For this purpose, a two flutes high-speed steel (HSS) cutting tool was used. The results showed that the up milling mode provides better surface roughness than down milling mode for almost all machined specimens. The feed rate is the main factor affecting the surface roughness, with a contribution of about 90%. The worst values of arithmetic roughness were observed, at low feed rate (0.05 mm/rev) regardless of the cutting velocity. The results also showed that machining parallel to fibers direction (0°) offers better surface roughness than machining perpendicular to fibers direction (90°). Microscopic and SEM images show some defects such as matrix cracking, cavity, fibers breakage, loss of matrix, fluffing, and thermal damage. [ABSTRACT FROM AUTHOR]

Objective speech intelligibility estimations undertaken in natural acoustics speech communications (NAS) scenarios require the utilization of a speech source that approximates the acoustic characteristics of a human talker. Only a limited number of special speech sources that conform to the specifications in the relevant guidelines are available in the market; however, they can be deemed expensive by professional practitioners and other users. Non-special and affordable loudspeakers are often used in NAS investigations in place of standardized special speech sources without the knowledge of their suitability and results validity. This study aims to examine the suitability of a range of representative common and affordable non-special loudspeakers as a potential alternative to standardized speech sources in NAS indicative or pilot investigations. Frequency response and Speech Transmission Index Public Address (STIPA) experimental results obtained from a reference standardized speech source were compared against results from various non-special loudspeakers measured utilizing diverse and real-world representative combinations of NAS acoustic conditions under controlled laboratory conditions. STIPA mean absolute errors for the alternative speech sources were generally lower than the STIPA method uncertainty and one Just Noticeable Difference (0.03 STI). The findings of this study will inform practitioners of the suitability of affordable loudspeakers when standardized special test loudspeakers are not available.

Understanding patterns of intraspecific trait variation can help us understand plant adaptability to environmental changes. To explore the underlying adaptation mechanisms of zonal plant species, we selected seven populations of Stipa krylovii, a dominant species in the Inner Mongolia Steppe of China, and evaluated the effects of phenotypic plasticity and genetic differentiation, the effects of climate variables on population trait differentiation, and traits coordinated patterns under each soil moisture treatment. We selected seeds from seven populations of S. krylovii in the Inner Mongolia Steppe, China, and carried out a soil moisture (2) × population origin (7) common garden experiment at Tianjin City, China, and measured ten plant traits of S. krylovii. General linear analyses were used to analyze how soil moisture and population origin affected each trait variation, Mantel tests were used to analyze population trait differentiation—geographic distance (or climatic difference) relationships, regression analyses were used to evaluate trait‐climatic variable relationships, and plant trait networks (PTNs) were used to evaluate traits coordinated patterns. Both soil moisture and population origin showed significant effects on most of traits. Aboveground biomass, root‐shoot ratio, leaf width, specific leaf area, and leaf nitrogen (N) content were significantly correlated with climate variables under the control condition. Specific leaf area and leaf N content were significantly correlated with climate variables under the drought condition. By PTNs, the hub trait(s) was plant height under the control condition and were aboveground biomass, root length, and specific leaf area under the drought condition. This study indicates that both phenotypic plasticity and genetic differentiation can significantly affect the adaptability of S. krylovii. In addition, soil moisture treatments show significant effects on trait‐climate relationships and traits coordinated patterns. These findings provide new insights into the adaptive mechanisms of zonal species in the semiarid grassland region. [ABSTRACT FROM AUTHOR]

Native bunchgrass communities dominated by Stipa pulchra are widely distributed in California but share dominance with non‐native annual grasses. Restoration of these grasslands focuses on altering the balance of native to non‐native grasses to favor the former. This study investigated the impact of burning on vegetation recovery. In the first postfire year burning showed a 70% reduction in cover of non‐native annual grasses (Bromus diandrus exhibited the greatest reduction) and minimal impact on S. pulchra recovery. In the following 3 years, S. pulchra recovered to levels comparable to controls, whereas the annual grasses remained below control levels until the fifth year. Also, in response to reduced annual grass cover on burned sites several species of non‐native Erodium increased from 10 to 30% relative cover, however, the low growth form of these forbs presented a less competitive threat to bunchgrasses than the non‐native annual grasses, and by the third postfire year returned to near control levels. The rare native geophyte Brodiaea kinkiensis was present throughout these grasslands and was not inhibited by burning treatments. To document the reliability of these patterns a second prescription burn was conducted on these sites 5 years after the first burn and vegetation recovery followed for the subsequent 4 years. Patterns observed after the first burn were duplicated following the second burn. The cover of S. pulchra varied in response to precipitation, with the 95% credible intervals of precipitation parameters overlapping zero, however, the cover of non‐native grasses varied greatly with precipitation and had similar trajectories in unburned and burned plots. [ABSTRACT FROM AUTHOR]

Objective speech intelligibility estimations undertaken in natural acoustics speech communications (NAS) scenarios require the utilization of a speech source that approximates the acoustic characteristics of a human talker. Only a limited number of special speech sources that conform to the specifications in the relevant guidelines are available in the market; however, they can be deemed expensive by professional practitioners and other users. Non-special and affordable loudspeakers are often used in NAS investigations in place of standardized special speech sources without the knowledge of their suitability and results validity. This study aims to examine the suitability of a range of representative common and affordable non-special loudspeakers as a potential alternative to standardized speech sources in NAS indicative or pilot investigations. Frequency response and Speech Transmission Index Public Address (STIPA) experimental results obtained from a reference standardized speech source were compared against results from various non-special loudspeakers measured utilizing diverse and real-world representative combinations of NAS acoustic conditions under controlled laboratory conditions. STIPA mean absolute errors for the alternative speech sources were generally lower than the STIPA method uncertainty and one Just Noticeable Difference (0.03 STI). The findings of this study will inform practitioners of the suitability of affordable loudspeakers when standardized special test loudspeakers are not available. [ABSTRACT FROM AUTHOR]

Aims: More intense and frequent droughts predicted for the future will heavily affect grasslands worldwide and, along with various other disturbances, possibly trigger major vegetation shifts. Therefore, documenting these changes and understanding the mechanisms behind them is essential. Our study aimed to investigate how dominant species in a semiarid grassland respond to a combination of small‐scale experimental disturbances and naturally occurring droughts and uncover the underlying mechanisms. Location: Central Hungary. Methods: We conducted a small‐scale disturbance experiment in a semiarid temperate grassland and followed recovery for 18 years, including severe drought events. In 1999, we established 16 sites, eight dominated by Festuca vaginata and another eight by Stipa borysthenica, the two dominant species of sand grasslands in the region. At each site, three permanent plots were marked that received either a cutting or digging treatment or remained as controls. We monitored the cover and density changes of Festuca and Stipa annually. Results: In the early years following the disturbance, Festuca recovered at a similar rate under both disturbance treatments, while Stipa recovered faster in cut than in dug plots. When natural drought events caused major diebacks of both species, Stipa recovered very quickly and regained dominance in initially Stipa‐dominated plots, and it also took over in initially Festuca‐dominated control and cut plots. However, digging at Festuca‐dominated sites delayed drought‐induced Stipa colonisation and thus favoured Festuca recovery. We found that the poor performance of Stipa in dug plots was related to sharply reduced seedling establishment, which resulted from the low number of seeds captured by the bare soil surface after digging. Conclusions: Our results demonstrate that recurring drought events may induce dominance shifts in temperate grasslands, but small‐scale disturbances can modulate vegetation responses. Our findings emphasise the importance of post‐disturbance regeneration patterns in drought‐induced vegetation shifts and show that seed dispersal strategy may have a major effect on vegetation dynamics. [ABSTRACT FROM AUTHOR]

In response to the new concept of the impact of total climate production factors on plant phenology, this study verifies the feasibility of simulating plant phenology and triggering thresholds based on total climatic production factors by using the phenological and meteorological observation data of S. krylovii plants from 1985 to 2018 at the Xilinhot National Climate Observatory of China Meteorological Administration. The results indicate that the total climate production factors have a significant impact on plant phenological changes and can be effectively utilized for simulating phenology and determining triggering thresholds. The mutation of cumulative climate production potential based on total climate production factors can effectively indicate the green-up date and the wilting date of S. krylovii plants, and their triggering thresholds depend on the parameters of climate resource changes and the characteristics of plant biology, which are (0.085, −5.363) and (0.086, −27.620), respectively. The cumulative climate production potential based on total climate production factors can effectively indicate the heading date of S. krylovii plants, and its triggering thresholds also depend on the parameters of climate resource changes and the characteristics of plant biology, which is (394.632, −38,026.268). Furthermore, the results support the viewpoint that abrupt changes to the climate determine the beginning and ending of plant growth, while the accumulative climate resources determine the other phenological dates. This study provides new ideas for the study of plant phenology. [ABSTRACT FROM AUTHOR]

Optimization of xylanase and cellulase production by a newly isolated Aspergillus fumigatus strain grown on Stipa tenacissima (alfa grass) biomass without pretreatment was carried out using a Box-Behnken design. First, the polysaccharides of dried and ground alfa grass were characterized using chemical methods (strong and diluted acid). The effect of substrate particle size on xylanase and carboxymethylcellulase (CMCase) production by the selected and identified strain was then investigated. Thereafter, experiments were statistically planned with a Box-Behnken design to optimize initial pH, cultivation temperature, moisture content, and incubation period using alfa as sole carbon source. The effect of these parameters on the two enzyme production was evaluated using the response surface method. Analysis of variance was also carried out, and production of the enzymes was expressed using a mathematical equation depending on the influencing factors. The effects of individual, interaction, and square terms on production of both enzymes were represented using the nonlinear regression equations with significant R2 and P-values. Xylanase and CMCase production levels were enhanced by 25% and 27%, respectively. Thus, this study demonstrated for the first time the potential of alfa as a raw material to produce enzymes without any pretreatment. A set of parameter combinations was found to be effective for the production of xylanase and CMCase by A. fumigatus in an alfa-based solid-state fermentation. [ABSTRACT FROM AUTHOR]

Aims: Numerous studies have investigated whether plant growth is limited by the availability of nitrogen or phosphorus (or both) in alpine grasslands. However, few studies have assessed N and P limitations on plant growth by comparing plant-microbial competition for N. Methods: An in situ 15N labeling experiment using NO3−, NH4+, and glycine was carried out with N and P additions in an alpine steppe on the Qinghai-Tibetan Plateau. Results: Plant biomass production in the alpine steppe was limited by N but not by P. Notably, N uptake of microorganisms and the dominant plant species, Stipa purpurea was greatly improved by N addition. Furthermore, the uptake of NH4+ by S. purpurea and other plants increased with P addition. The addition of N and P together promoted the uptake of NO3− by microorganisms. Alleviating N limitation (i.e., N or NP fertilization) resulted in a higher uptake of N by microorganisms than that by S. purpurea. Conclusion: Nitrogen enrichment promoted the dominant competitive role of microorganisms over plants in terms of N uptake in the short term. This study provides a comprehensive basis for plant N uptake during the process of alleviating nutrient limitation in alpine grasslands by comparing short-term plant-microbial competition. [ABSTRACT FROM AUTHOR]

Samples of soil and aerial mass of Calamagrostis acutiflora were obtained from an urban area adjacent to a street. The sampled material was analyzed to determine the content of Fe, Mn, Zn, Cu, Pb, Cd, Ni, Cr and Co, in addition to which soil was analyzed for the content of total organic carbon (TOC), salinity (EC) and reaction (pH). Based on the results, the enrichment factor (EF) and biological accumulation coefficient (BAC) of heavy metals as well as correlations between the analyzed characteristics were calculated. The content of heavy metals in the soil did not exceed the standards set for transportation areas, but the EF value implicated anthropogenic enrichment of soils with Zn, Cu, Pb, Cd and Co. Numerous, highly significant and positive correlations were obtained between the content of the elements in the soil, plants and in the soil-plant system, which suggests their relatively high bioavailability. The BAC values achieved for Co, Cr, Cu, Cd and Ni indicate that Calamagrostis acutiflora can be a useful species for phytoextraction of these elements from urban soils. Moreover, Calamagrostis acutiflora is a good choice for planting in urban areas due to its good adaptability, long growing season and tall conformation. This study enabled us to the determine the usefulness of Calamagrostis acutiflora for phytoextraction of heavy metals (Fe, Mn, Zn, Cu, Pb, Cd, Ni, Cr and Co) from urban soils exposed to transportation pressure. This aspect of the said grass species has not been evaluated previously; meanwhile, owing to its high esthetic value, the grass can be an interesting choice in the landscaping of urban areas. The evaluation was based on determinations of the elements in the soil and in aerial biomass of Calamagrostis acutiflora sampled from an urban area adjacent to a busy street. The phytoremediation potential of Calamagrostis acutiflora was assessed according to the calculated biological accumulation coefficient (BAC). Furthermore, the enrichment factor (EF) for the heavy metals in the soil was determined, which enabled us to identify the extent of anthropogenic pressure in this area. Other determinations included basic soil physicochemical properties (TOC, pH, EC), which in practice will facilitate a choice of sites to be planted with Calamagrostis acutiflora in the future. [ABSTRACT FROM AUTHOR]

Investigating the genetic mechanisms of local adaptation is critical to understanding how species adapt to heterogeneous environments. In the present study, we analyzed restriction site-associated DNA sequencing (RADseq) data in order to explore genetic diversity, genetic structure, genetic differentiation, and local adaptation of Stipa breviflora. In total, 135 individual plants were sequenced and 25,786 polymorphic loci were obtained. We found low genetic diversity (He = 0.1284) within populations of S. breviflora. Four genetic clusters were identified along its distribution range. The Mantel test, partial Mantel test, and multiple matrix regression with randomization (MMRR) indicate that population differentiation was caused by both geographic distance and environmental factors. Through the FST outlier test and environmental association analysis (EAA), 113 candidate loci were identified as putatively adaptive loci. RPK2 and CPRF1, which are associated with meristem maintenance and light responsiveness, respectively, were annotated. To explore the effects of climatic factors on genetic differentiation and local adaptation of S. breviflora, gradient forest (GF) analysis was applied to 25,786 single nucleotide polymorphisms (SNPs) and 113 candidate loci, respectively. The results showed that both temperature and precipitation affected the genetic differentiation of S. breviflora, and precipitation was strongly related to local adaptation. Our study provides a theoretical basis for understanding the local adaptation of S. breviflora. [ABSTRACT FROM AUTHOR]

Clarifying the response of plant phenology to drought duration is helpful for accurately interpreting and predicting carbon sinks in ecosystems. Based on the response of different phenological periods of the dominant species Stipa krylovii to monthly, seasonal, and semiannual time scale drought in the typical steppe of Inner Mongolia from 1983 to 2018, the results revealed that (1) the start of the growing season (SOS) was characterized by an advance–delay–advance pattern, and the heading stage (HOS), flowering stage (FOS), and end of the growing season (EOS) all showed consistent advanced trends, which provided additional insight into the conclusions of previous studies that found the SOS was advanced in arid and semiarid regions. (2) The response mechanism of the SOS to the timing of drought was not consistent. Among the response mechanism, the SOS was delayed because of the January–February drought at different time scales but advanced because of the April drought at different time scales. The HOS/FOS was delayed by the June–July drought at different time scales, and the EOS was advanced by the August–September drought at different time scales. (3) More importantly, the SOS, HOS, FOS, and EOS were affected by predrought and its persistence, and the effects were greater the closer to the phenological periods that drought occurred. (4) At the monthly scale, droughts in January, June, and August were the critical drought periods affecting the SOS, HOS/FOS, and EOS, while seasonal and semiannual scale droughts in February, June–July, and September were the critical periods affecting the SOS, HOS/FOS, and EOS. The results of this study enrich our understanding of how drought at different time scales affects different phenological periods, providing a basis for improving plant phenological models. [ABSTRACT FROM AUTHOR]

Reducing accidents, deaths, and serious injuries is an objective to be achieved by every health and road authority. To avoid road leaving, rigid barriers or stretched cables are used at the edges of the roads. These structures are based on metallic materials. This paper presents an innovative structure based on a composite reinforced with natural esparto stems as road barriers absorbing shock energy. The structure is lightened and reinforced by tensioned cables to ensure the prestressing of the whole. Prestressing is a technique widely used in civil engineering but rarely in composites. To develop new crash beam barriers based on Epoxy/Alfa10% material, Charpy tests were conducted to determine the absorbed energy per section of material per weight. Knowing the energy to be absorbed, the section and weight of the barrier can be designed. In this paper, physical tests were conducted on solid, solid-compressed, perforated, and perforated-cable-reinforced specimens according to the ASTM E23-18 standard. The results show that the compression prestressing improves the Epoxy impact energy absorption by 37.22%. The Epoxy/Alfa10% composite compression prestressing improves the absorbed energy by 67.7%. The Epoxy/Alfa10% compressed, perforated, and reinforced by cables composites gives a better result than the raw Epoxy material, with a minimum improvement of 22.69% with respect to the ratio Resilience value of Charpy V-notch specimen (KCV)/weight. Reinforcement of holed samples with cables gives the best energy absorption results on all experimental tests for both materials with a value of 8.83 J. Finite element models calibrated on Aluminum to be predictive are developed for the four types of specimens. [ABSTRACT FROM AUTHOR]