Caragana Korshinskii Research Articles

Green degradation of Caragana korshinskii to valuable bio-oils in supercritical CO2-ethanol: Evaluation of CH and O moieties

An eco-friendly supercritical CO2 (scCO2)-ethanolysis system was designed to convert Caragana korshinskii (Ck) into valuable bio-oils. Hydrocarbons and O-containing moieties (CH and O classes) in derived soluble portions (SPs) were evaluated in detail. The results show that scCO2-ethanol has synergistic degradation ability and strong permeability to complex structures. Optimal conditions were determined to be 10 mL g−1 ethanol/Ck ratio, 1 MPa initial CO2 pressure, 300 °C, and 60 min holding time based on the SP yield and the maximum yield is 38.2 wt% with high heating value of 24.06 kJ g−1. The difference of SPs between conventional ethanolysis (SPE) and scCO2-ethanolysis (SPSE) was compared. According to FTIR and GC/MS analyses, the distribution of functional groups and detectable group components is similar, and O-containing species are dominant. Tetrahydrofurans & furans, alkoxy-substituted benzenes & alkoxy-substituted phenols, and ketones & esters are main group components. The characteristic differences of >C-O- and >CO classes are related to the following three aspects: (1) the ring-opening, >C-O- bond cleavage, cyclization, and condensation of cellulose/hemicellulose, (2) the destruction of abundant >Car-O- in lignin, especially guaiacyl and syringyl units, and (3) the formation of ethyl esters promoted by the nucleophilic attack of ethoxy group. Orbitrap MS analysis further confirmed that O-containing species of SPE and SPSE are mainly concentrated in O1-O4 classes, and scCO2-ethanolysis promotes the acquisition of sugars and bioactive fragments from Ck. In addition, the characteristic distribution of On classes in SPSE is related to the release of natural oxygenates, cleavage of weak/intermediate-strength covalent bonds, and dissociation of O-containing macromolecules. This study provides a reference perspective and a potential implementation approach for the clean and efficient utilization of Ck to produce valuable bio-oils.

Rapid and Non-Destructive Estimation of Moisture Content in Caragana Korshinskii Pellet Feed Using Hyperspectral Imaging.

Moisture content is an important parameter for estimating the quality of pellet feed, which is vital in nutrition, storage, and taste. The ranges of moisture content serve as an index for factors such as safe storage and nutrition stability. A rapid and non-destructive model for the measurement of moisture content in pellet feed was developed. To achieve this, 144 samples of Caragana korshinskii pellet feed from various regions in Inner Mongolia Autonomous Region underwent separate moisture content control, measurement using standard methods, and captured their images using a hyperspectral imaging (HSI) system in the spectral range of 935.5-2539 nm. The Monte Carlo cross validation (MCCV) was used to eliminate abnormal sample data from the spectral data for better model accuracy, and a global model of moisture content was built by using partial least squares regression (PLSR) with seven preprocessing techniques and two spectral feature extraction techniques. The results showed that the regression model developed by PLSR based on second derivative (SD) and competitive adaptive reweighted sampling (CARS) resulted in better performance for moisture content. The model showed predictive abilities for moisture content with a coefficient of determination of 0.9075 and a root mean square error (RMSE) of 0.4828 for the training set; and a coefficient of determination of 0.907 and a root mean square error (RMSE) of 0.5267 for the test set; and a relative prediction error of 3.3 and the standard error of 0.307.

Estimating rainfall interception of xerophytic deciduous shrubs by static- and variable-parameter Gash models with stem- and leaf-dominated canopy water storage

The precise modeling of rainfall interception is important to understand the water balance of forest ecosystems, particularly in water-stressed restoration regions. However, xerophytic deciduous shrubs are currently underrepresented in rainfall interception models due to the significant variations in their canopy structures. Therefore, we estimated the rainfall interceptions of four representative deciduous shrubs (Spiraea pubescens, Potentilla fruticose, Hippophae rhamnoides, and Caragana korshinskii) in the semiarid region of northern China using the revised Gash model (RG model) with static parameters and a modified Gash model (MG model) with variable parameters. The results indicate that the MG model outperformed the RG model in studies of S. pubescens and P. fruticose, with regard to the modeling error (6.6%–7.9%), Nash–Sutcliffe model efficiency (0.68–0.86), and the root-mean-square error (0.17–0.71). However, the RG model was better than the MG model for H. rhamnoides and C. korshinskii, with regard to the modeling error (3.6%–6.3%), Nash–Sutcliffe model efficiency (0.82–0.94), and the root-mean-square error (0.17–0.66). The MG model was highly sensitive to changes in the leaf area index, canopy cover, mean evaporation rate, canopy storage capacity, and leaf storage capacity for S. pubescens and P. fruticose. Nevertheless, the RG model demonstrated high sensitivity to changes in the canopy storage capacity and stem storage capacity for H. rhamnoides and C. korshinskii. These indicated that canopy storage capacity has a significant effect on the rainfall interception capabilities of different shrub species, as indicated by both the RG and MG models. This critical indicator was determined by the water storage of stems for H. rhamnoides and C. korshinskii (ranged contribution of 59.5%–81.6%), whereas the water storage of leaves for S. pubescens and P. fruticose (with contributions of 51.3%–80.7%). Therefore, the optimized RG and MG models are recommended for estimating the rainfall interception of xerophytic shrubs with stem-dominated water storage and leaf-dominated water storage, respectively. This study categorizes the applicability of rainfall interception models in terms of important plant traits to precisely assess the water balance of xerophytic deciduous shrub ecosystems. In future studies, leaf configuration and hydrophobicity are highly recommended to be quantified for further improving rainfall interception models.

Stemflow temporal dynamics differ significantly between standing live and dead branches of two xerophytic shrub species

Shrub mortality due to self-thinning and climate change is a natural consequence of the long residence times of standing dead branches in unmanaged shrub plantations. Stemflow (SF) represents a key point source of input water and nutrients into the soil in shrub ecosystems. However, little information is available about how shrub mortality affects SF variables. In this study, we measured the SF volume (SFV), funneling ratio (FR), SF intensity, time lag to rain, and rainfall characteristics for live and standing dead branches of two major shrub species comprising Caragana korshinskii and Salix psammophila during the rainy season in 2022 on the Chinese Loess Plateau. The results demonstrated that the SF variables and temporal dynamic processes differed between standing live and dead branches of the two shrubs. For C. korshinskii, the mean SFV and FR were 1.9 and 1.8 times higher for live branches than dead branches, respectively, whereas for S. psammophila, the mean SFV and FR were 1.3 and 1.6 times higher for dead branches than live branches. These contradictory results can be explained by differences in the canopy structures of the species, such as the surface area that contributes to the generation of SF in the upper canopy, branch angles, and the degree of branch bark decomposition and decay. In addition, the SF variables were significantly temporally dependent on the rainfall characteristics. SFV, SFI, and SFD were positively and linearly correlated with the rainfall amount, intensity, and duration at the inter-event scale (P < 0.001). The influence of rainfall intensity on SF time lag to rain were not significant at the intra-event scale (P > 0.05). Considering the enrichment ratio due to canopy dry deposition and bark decomposition, the periodic flattening of dead S. psammophila branches to restore their growth is less significant than allowing them to die and renew naturally. These findings may serve as a reference for developing management practices for shrub species in areas with soil water and nutrient deficiencies.

Phytoremediation strategies for heavy metal-contaminated soil by selecting native plants near mining areas in Inner Mongolia.

Phytoremediation technology, as an eco-friendly and cost-effective approach, is widely used to restore soil contaminated by heavy metal(loid)s. However, the adaptability and absorption capacity of plants to multiple elements are the crucial factors affecting the application of phytoremediation in mining areas. In this study, dominant native plant species and their paired soils were collected near a lead-zinc mine in Inner Mongolia, to assess the ecological risk of heavy metal(loid)s and phytoremediation potential. The results showed that Cd and As were the dominant soil pollutants, with levels of 90.91% and 100%, respectively, exceeding the risk intervention values for soil contamination of agricultural land. The rates of Pb, Cu, and Zn exceeding the risk screening values were 69.70%, 60.61%, and 96.97%, respectively. Extremely high ecological risk of heavy metal(loid)s was observed in this area. The ability of native plants accumulating heavy metals varied among species. The bioconcentration factor (BCF) varied from 0.14 to 2.59 for Cd, 0.02 to 0.45 for As, 0.06 to 0.76 for Pb, 0.05 to 2.69 for Cr, 0.15 to 1.00 for Cu, and 0.22 to 4.10 for Zn. Chinese Cinquefoil Herb (Potentilla chinensis Ser.) showed the potential to accumulate multiple toxic elements based on the biomass, shoot content, translocation factor (TF), BCF, and metal extraction rate (MER), while, other species showed the potential to accumulate single toxic element: goosefoot (Chenopodium album L.), Lespedeza daurica (Laxm.) Schindl. and peashrubs (Caragana korshinskii Kom.), Herba Artemisiae Scopariae (Artemisia capillaris Thunb.), alfalfa (Medicago sativa L.), and Moldavian Dragonhead (Dracocephalum moldavica L.) for Cd, As, Cr, Cu, and Zn, respectively. Furthermore, wild leek (Allium ramosum L.), cogongrass (Imperata cylindrica (L.) Beauv.), fringed sagebrush (Artemisia frigida Willd.), and field bindweed (Convolvulus arvensis L.) were selected for phytostabilization of specific elements, considering the heavy metal contents in the roots and low TF values. This study provides a reference for selecting appropriate species for the remediation of heavy metal-contaminated soils in certain mining areas.

Arbuscular mycorrhizal inoculation alleviates water competition between adjacent plants in the mixed planting system

Exploring the water use strategies of different plant species is very important in understanding the mechanisms of soil-plant interactions in water-limited ecosystems. There is limited information on changes in plant water use in mixtures of species, and little is known of the role of arbuscular mycorrhizal fungi in regulating the water use strategies of host plants in mixtures. The water use strategies of three plant communities in arid and semi-arid mining areas were investigated. These were Medicago sativa (alfalfa) in monoculture (A), Caragana korshinskii (Korshinsk pea shrub) in monoculture (C), and Medicago sativa + Caragana korshinskii in mixture (MIX). Each plant community was inoculated with an arbuscular mycorrhizal fungus or uninoculated to determine the regulation of plant water use strategy by the fungus. There was a significant difference in the use of soil water by both plant species in mixture compared with monoculture (P < 0.05). In the mixture there was significant competition for water between depths 0–40 cm and 40–100 cm. Both species took up more water from the surface soil than in monoculture. Mycorrhizal inoculation reduced the dependence of the plants on surface soil water, effectively alleviated the competition for water between the two plant species in mixture. The results indicate that the impact of arbuscular mycorrhizal fungi on the water use strategies of different plant species in mixtures should be considered when ecological restoration of vegetation is carried out in arid and semi-arid areas.

Afforestation vegetation uses water from very deep soil layers in the semi‐arid Loess Plateau

AbstractInvestigating the availability of water in very deep soil layers for vegetation is important for assessing the eco‐hydrological effects of the thick loess soil and optimizing soil water management and vegetation restoration initiatives. However, the proportion of soil water sourced from the soil layer deeper than 300 cm by typical afforestation species on the Loess Plateau, along with its seasonal variations, remains unclear. In this study, we examined the composition of the water sources used by two typical afforestation plant species (Caragana korshinskii and Medicago sativa) from soil depths of up to 10 m during the growing season, using isotopic analysis. The results showed that soil desiccation occurred in the soil layers of 260–1000 cm and 260–700 cm at the upper and lower slope positions, respectively, for both species plots. Relative stability of the isotopic values in &gt;260 cm soil layers explained a piston flow occurred in these layers. The contribution proportion of soil water in 260–1000 cm was at 41.7% ± 9.0% and 51.3% ± 8.8% for C. korshinskii on upper and lower slope, respectively and was at 67.6% ± 6.7% and 73.7% ± 7.0% for M. sativa on upper and lower slope, respectively. The serious soil desiccation was induced by the dependence on very deep soil water and the slow recharge with the piston flow. Meanwhile, C. korshinskii converted the main water source between 0–260 cm and 260–1000 cm in different seasons. In contrast, M. sativa used water mainly from soil layers deeper than 260 cm in June and increased the utilization proportion of deeper water sources in July and September. The persistent dependence on very deep soil water for M. sativa, induced a deeper desiccation depth as compared to C. korshinskii. Thus, thinning to the optimal leaf area index and converting to natural grassland were recommended for C. korshinskii and M. sativa plots, respectively to restore the depleted soil water and to promote water cycle.

Plant selection and ecological microhabitat drive the shrub-associated microbiome selection in revegetated shrub ecosystems

Shrubs are commonly used for revegetation in degraded dryland ecosystems worldwide, and their introduction can recruit a large number of microbes from the soil. However, the assembly of plant-associated microbiomes and the effect of the introduction of plants on soil and plant-associated microbiomes remain unclear. In this study, we investigated shrub-associated microbes from five ecological microhabitats, including the leaves, litter, roots, rhizosphere, and root zone, across four xeric shrub plantations (Artemisia ordosica, Caragana korshinskii, Hedysarum mongolicum, and Salix psammophila), using 16S and internal transcribed spacer2 rRNA gene sequencing. We found that the changes in the bacterial and fungal communities were more influenced by the microhabitats than by the plant species, with distinct niche differentiation. Microbial source tracking and nestedness analysis showed that the shrub-associated bacteria primarily originated from the bulk soils and were slightly selected in the different microhabitats; this similar pattern was not observed in the shrub-associated fungi. Furthermore, the surrounding zone of roots was a hot spot for microbial recruitment in revegetated shrubs. Null model analysis indicated that the deterministic and stochastic process dominated the assembly of bacterial and fungal communities, respectively. Our findings suggest that ecological microhabitats of revegetated shrublands strongly influence the bacterial and fungal compositions of the plant microbiome. This study enhances our understanding of the mechanism underlying the plant-soil microbiome feedback during the initial plant-establishment period in dryland ecosystems. Furthermore, our insights can assist in the development of effective strategies for establishing and managing vegetation sustainably in drylands.

Effects of lactic acid bacteria and molasses on the fermentation quality, in vitro dry matter digestibility, and microbial community of Korshinsk peashrub (Caragana korshinskii Kom.) silages harvested at two growth stages

AbstractThis study investigated the effects of additives on fermentation quality, in vitro digestibility and microbial communities of Korshinsk peashrub (Caragana korshinskii Kom.) silages at different maturity stages. Korshinsk peashrub was harvested at budding (S1) and blooming (S2) stages, and ensiled without additives (CON), or with 5% molasses (M0), or a combination of 5% molasses and either L. plantarum CLP (M1) or L. plantarum L694 (M2). Each treatment was triplicated and ensiled for 60 days. Delayed harvest increased water soluble carbohydrates (WSC), neutral detergent fibre (aNDF) and acid detergent fibre (ADF) in silages at S2 stage, whereas crude protein (CP) was lower in silages at S1 stage. Compared with the CON group, the additives treated silages had lower pH, greater lactic acid (LA), acetic acid (AA), and WSC concentrations (p &lt; .05). Application of molasses alone or in combination with CLP had a noticeable effect on bacterial communities, with an increase in Lactobacillus in silages at both stages, whereas M2 silages presented more unfavourable microorganisms. Spearman's rank correlation analysis showed that LA concentration in silage was positively correlated with Lactobacillus relative abundance at both stages, while ammonia nitrogen (NH3‐N) concentration was positively correlated with the relative abundances of unclassified‐f‐Enterobacteriaceae and Enterobacter. In conclusion, delayed harvest could result in greater WSC and aNDF but lower CP in Korshinsk peashrub silage. Low WSC is the primary limiting factor affecting silage quality, and ensiling with molasses accelerated lactic acid fermentation in Korshinsk peashrub silage, providing a high‐quality forage resource for livestock production.

Soil Moisture Dynamics and Its Temporal Stability under Different-Aged Caragana korshinskii Shrubs in the Loess Hilly Region of China

Soil moisture has a great influence on vegetation growth and survival in arid and semiarid regions. Information about deep soil moisture dynamics is vital for restoring vegetation and improving land management on the water-limited Loess Plateau. The spatiotemporal dynamics and temporal stability of deep soil moisture (at a soil depth of 600 cm) were observed in situ under Caragana korshinskii shrubs that had various stand ages (named CK-10yr, CK-20yr and CK-35yr) in the Loess hilly region of China. The results showed that under C. korshinskii, soil moisture generally decreased as the stand age rose. Meanwhile, its moisture was consistent with precipitation variation, and an obvious time lag in soil moisture was found compared to that in precipitation during the entire growing season. Along the soil profile, a transition belt linking the shallow with deep soil moisture occurred at a 200 cm soil depth in different slope positions and aspects. At the slope scale, both the slope aspect and slope position significantly affected soil moisture variation in the areas with planted C. korshinskii shrubs, experiencing a decreasing trend from semi-shady slopes to sunny ones and from lower positions to upper ones. However, the variance in soil moisture between different positions and slope aspects was small. For the slope aspect, except for CK-20yr, the different-aged C. korshinskii shrubs had higher soil moisture content on sunny slopes than on semi-shady slopes at the upper 0–200 cm soil depth, while the opposite was true at the 200–600 cm soil depths. For slope positions, the soil moisture variation was small between the 0 and 200 cm soil depths and larger between the 200 and 600 cm soil depths. Within the whole profiles, the representative depth under the C. korshinskii shrubs for the soil moisture content was mainly concentrated between the 400–500 cm soil depths, on average, showing a gradual deepening trend with increasing restoration age. In summary, the findings indicate that natural recovery with low-water consumption grasslands and manual management measures, such as thinning and mowing, should be strengthened to minimize the high soil moisture consumption rates that occur in a healthy soil moisture environment and maintain sustainable vegetation restoration.

Porous N-doped carbon converted from protein-rich shrub enables record-high removal of p-nitrophenol: superior performance and mechanism

The complete removal of harmful phenolic contaminants from water remains huge challenge because of the lack of cost-effective and powerful adsorbents. Herein, a sustainable nitrogen self-doped biochar (named KBC750N) with large specific surface area (1398.44 m2/g), high adsorption capacity (606.06 mg/g) and removal ratio (99.99%) for p-nitrophenol (PNP) in real waters (Seawater, Yangtze River water, and Yellow River water) was prepared from a naturally abundant protein-rich psammophyte Caragana korshinskii (CK) by a facile one-step pyrolysis process. The in-situ nitrogen-doped biochar shows much better adsorption removal efficiency of 99.99% toward PNP than expensive commercial adsorbents (only 77.52%). The biochar still keeps high adsorption efficiency after reused more than five times. Site energy distribution analysis revealed that the biochar captures PNP mainly through n–π and π–π electron-donor–acceptor interactions among the electron-rich functional groups (N-containing moieties, –COOH, and –OH), graphite carbon, and PNP. Density functional theory (DFT) calculations confirmed that the nitrogen site in biochar helps to strengthen its adsorption capability to PNP. This work provides a sustainable platform for the development of high-performance, cost-effective materials for efficient elimination of organic pollutants from water.

Deep soil water use of old-aged vegetation (17- to 36-year stand age) after the formation of dried soil layers based on in situ monitoring

Study regionXindiangou Watershed in Suide, the Loess Plateau, China Study focusDeep soil water (DSW) is gradually depleted as vegetation stand age increases, resulting in dried soil layers (DSLs) in the Loess Plateau in China. However, it is unclear whether old-aged vegetation continues to use DSW under DSLs. This study monitored soil water five times (2001, 2005, 2006, 2007, 2020) in the deep profile for three common vegetation types [Pinus tabuliformis Carr. (P. tabuliformis), Caragana korshinskii Kom. (C. korshinskii), Platycladus orientalis L. Franco (P. orientalis)] planted in 1985. In 2020, we measured soil water content, root characteristics, and soil particle composition to investigate DSW status and the influencing factors. New hydrologic insights for the regionSoil water in the 2–10 m soil layer did not significantly differ from 17- to 36-year stand for the three vegetation types (p < 0.05), indicating that old-aged vegetation no longer used DSW with a strong soil desiccation index in 2–10 m. P. tabuliformis (23- to 36-year stand) used DSW in the 17–22 m with an average consumption of 11.6 mm year–1, while old-aged C. korshinskii did not use DSW. DSW under long-term depletion correlated significantly with clay content. This study showed unfavorable DSW resources for water use under old-aged vegetation, with further measures to conduct selective thinning or complementary planting considered to alleviate the DSW deficit.

Stable isotopic analysis of water utilization characteristics of four xerophytic shrubs in the Hobq Desert, Northern China.

Quantitative identification of water utilization characteristics of xerophytic shrubs is an important prerequisite for the selection and optimization of a regional artificial sand-fixing vegetation system. In this study, a hydrogen (δD) stable isotope technique was used to study the changes in water use characteristics of four typical xerophytic shrubs, Caragana korshinskii, Salix psammophila, Artemisia ordosica, and Sabina vulgaris in the Hobq Desert under light (4.8mm after 1 and 5 days) and heavy (22.4mm after 1 and 8 days) rainfall events. Under light rainfall, C. korshinskii and S. psammophila primarily used the 80-140 cm layer of soil water (37-70%) and groundwater (13-29%), and the water use characteristics did not change significantly after the light rainfall event. However, the utilization ratio of A. ordosica to soil water in the 0-40 cm layer increased from less than 10% on the first day after rain to more than 97% on the fifth day after rain, whereas the utilization ratio of S. vulgaris to soil water in the 0-40 cm layer also increased from 43% to nearly 60%. Under heavy rainfall, C. korshinskii and S. psammophila still used the 60-140 cm layer (56-99%) and groundwater (~15%), while the main water utilization depth of A. ordosica and S. vulgaris expanded to 0-100 cm. Based on the above results, C. korshinskii and S. psammophila primarily use the soil moisture of the 80-140 cm layer and groundwater, while A. ordosica and S. vulgaris use the soil moisture of the 0-100 cm layer. Therefore, the co-existence of A. ordosica and S. vulgaris will increase the competition between artificial sand-fixing plants, while the combination of the two plants with C. korshinskii and S. psammophila will avoid competition between artificial sand-fixing plants to some extent. This study provides important guidance for regional vegetation construction and sustainable management of an artificial vegetation system.

Efficient Secretory Production of Lytic Polysaccharide Monooxygenase BaLPMO10 and Its Application in Plant Biomass Conversion.

Lytic polysaccharide monooxygenases (LPMOs) can oxidatively break the glycosidic bonds of crystalline cellulose, providing more actionable sites for cellulase to facilitate the conversion of cellulose to cello-oligosaccharides, cellobiose and glucose. In this work, a bioinformatics analysis of BaLPMO10 revealed that it is a hydrophobic, stable and secreted protein. By optimizing the fermentation conditions, the highest protein secretion level was found at a IPTG concentration of 0.5 mM and 20 h of fermentation at 37 °C, with a yield of 20 mg/L and purity > 95%. The effect of metal ions on the enzyme activity of BaLPMO10 was measured, and it was found that 10 mM Ca2+ and Na+ increased the enzyme activity by 47.8% and 98.0%, respectively. However, DTT, EDTA and five organic reagents inhibited the enzyme activity of BaLPMO10. Finally, BaLPMO10 was applied in biomass conversion. The degradation of corn stover pretreated with different steam explosions was performed. BaLPMO10 and cellulase had the best synergistic degradation effect on corn stover pretreated at 200 °C for 12 min, improving reducing sugars by 9.2% compared to cellulase alone. BaLPMO10 was found to be the most efficient for ethylenediamine-pretreated Caragana korshinskii by degrading three different biomasses, increasing the content of reducing sugars by 40.5% compared to cellulase alone following co-degradation with cellulase for 48 h. The results of scanning electron microscopy revealed that BaLPMO10 disrupted the structure of Caragana korshinskii, making its surface coarse and poriferous, which increased the accessibility of other enzymes and thus promoted the process of conversion. These findings provide guidance for improving the efficiency of enzymatic digestion of lignocellulosic biomass.

Genome-Wide Analysis of WRKY Transcription Factors Involved in Abiotic Stress and ABA Response in Caragana korshinskii.

The WRKY transcription factor family plays a vital role in plant development and environmental response. However, the information of WRKY genes at the genome-wide level is rarely reported in Caragana korshinskii. In this study, we identified and renamed 86 CkWRKY genes, which were further classified into three groups through phylogenetic analysis. Most of these WRKY genes were clustered and distributed on eight chromosomes. Multiple sequence alignment revealed that the conserved domain (WRKYGQK) of the CkWRKYs was basically consistent, but there were also six variation types (WRKYGKK, GRKYGQK, WRMYGQK, WRKYGHK, WKKYEEK and RRKYGQK) that appeared. The motif composition of the CkWRKYs was quite conservative in each group. In general, the number of WRKY genes gradually increased from lower to higher plant species in the evolutionary analysis of 28 species, with some exceptions. Transcriptomics data and RT-qPCR analysis showed that the CkWRKYs in different groups were involved in abiotic stresses and ABA response. Our results provided a basis for the functional characterization of the CkWRKYs involved in stress resistance in C. korshinskii.

Multi‐functional characteristics of artificial forests of Caragana korshinskii Kom with different plantation ages in the hilly and sandy area of Northwest Shanxi, China

AbstractTo explore the multi‐functional characteristics of an artificial Caragana korshinskii ecosystem with different plantation ages, we assessed the differences in ecosystem multi‐functionality, the main influencing factors, and recovery dynamics over 6, 12, 18, 40, and 50 years. The results showed a binomial correlation between planting age and regulatory function (p &lt; 0.05, R2 = 0.459), and a significant linear positive correlation between the multi‐functionality index and supporting and provisioning services. Meanwhile, a significant trinomial correlation was observed among planting age, nutrient transformation, and nutrient cycle (p &lt; 0.01, R2 = 0.754), whereas a linear positive correlation (p &lt; 0.05) was detected between plantation age and plant nutrient uptake, soil fertility, maintenance of plant diversity, aboveground primary productivity, and ecosystem multi‐functionality. The multi‐functionality index was significantly positively correlated with plant nutrient uptake, soil fertility, maintenance of plant diversity, and aboveground primary productivity. Plant diversity maintenance, aboveground primary productivity, and water conservation all had significant effects on the multi‐functionality index. The ecosystem multi‐functionality of C. korshinskii forests significantly increased with the increase of plantation age, and C. korshinskii establishment considerably improved plant nutrient uptake, soil fertility, maintenance of plant diversity, aboveground primary productivity, and ecosystem multi‐functionality. The water conservation function of the ecosystem peaked 12 years after planting C. korshinskii, and considerably decreased 40 years after planting, indicating that the limiting factors must be accounted for when evaluating ecosystem multi‐functionality in arid and semi‐arid areas.

Vegetative substrate configuration technology for tower foundation slope of transmission line in arid area considering species suitability

AbstractIn order to realize the ecological restoration of transmission line tower foundation slope and enrich the research methods of slope ecological restoration, this paper studies a nutrient matrix configuration technology for transmission line tower foundation slope in arid areas. The Xilingol arid grassland area in Inner Mongolia is selected as the research object, and plants such as Leymus chinensis, Festuca arundinacea and Agropyron pratense are selected as the grass species of the vegetative substrate configuration technology. Different proportions of water retaining agent, compound fertilizer, microbial agents and other substances are added to the soil, which are combined into 10 test groups. The effect of slope ecological restoration is verified by species suitability, physical and chemical properties of matrix and plant growth. The resβults showed that Caragana korshinskii, Artemisia annua, Astragalus adsurgens, Sonchus oleraceus and other plants are the dominant grass species in the plant substrate plants; The physical and chemical indexes of soil's bulk density, organic matter, total nitrogen and so on in group B2 are better than those in other groups. Adopting the vegetative substrate configuration technology with the proportion of group B2 can obtain a good ecological restoration effect of tower foundation slope of transmission line in arid areas. The vegetative substrate configuration technology can solve the long‐standing ecological and environmental protection problems of the tower foundation slope of transmission line in arid areas, and should be actively promoted and applied. Daur lymphatic is also widely used in ecological restoration of transmission line base slope in arid region. The average coverage rate was 14.85%. The average height was 100.5 cm. It could grow at an altitude of more than 1000 m. After the nutrient matrix of the transmission line base slope was configured, the grass planting belt was established under normal maintenance, and the seeds began to germinate 3 days later. After 10 days, the germination rate was 78% and the coverage rate was 65%.

How root and soil properties affect soil detachment capacity in different grass–shrub plots: A flume experiment

Grasses and shrubs play important roles in preventing soil erosion. However, the mechanism of their impact on soil detachment is still unclear. Therefore, this study examined the following combinations of typical grass–shrub sample plots on the Loess Plateau: Caragana korshinskii (JJ), C. korshinskii and Agropyron cristatum (JC), C. korshinskii and Bothriochloa ischaemum (JB), and C. korshinskii and Artemisia gmelinii (JH). The variation characteristics of the soil detachment rate with depth (0–30 cm) and at different locations (0 cm, 50 cm) from the base of shrubs under a fixed flow rate and slope were explored. The spatial heterogeneity of the detachment rate in the grass–shrub plots was strong. In different plots, the soil detachment rate at 50 cm from the base of the shrub was relatively low. The ability of root length to reduce the detachment rate varied. In the JJ sample plot, the root length at the shrub base had a relatively strong ability to reduce the detachment rate, while it showed the opposite trend in the other plots. The ability to reduce the detachment rate was higher in the JC and JB plots at 0–5 cm than in the JH plots. However, at 20–30 cm, the opposite trend was observed. Overall, with the exception of the JC plots, the soil detachment rate in the other mixed plots was lower than that in single-species plots. In this study, soil aggregates and root length density were the main factors affecting the soil detachment rate. The combination of the two could also better calculate the soil detachment rate (R2 = 0.80). Compared with traditional regression methods, the back propagation neural network model had a relatively high R2 (0.86) when predicting the soil detachment rate. This study revealed the mechanisms underlying differences in soil detachment capacity in different grass–shrub sample plots.

Hormonal Balance, Photosynthesis, and Redox Reactions in the Leaves of Caragana korshinskii Kom. under Water Deficit.

To evaluate the physiological responses of Korshinsk peashrub (Caragana korshinskii Kom.) to water deficit, photosynthetic gas exchange, chlorophyll fluorescence, and the levels of superoxide anion (O2•-), hydrogen peroxide (H2O2), malondialdehyde (MDA), antioxidant enzymes, and endogenous hormones in its leaves were investigated under different irrigation strategies during the entire growth period. The results showed that leaf growth-promoting hormones were maintained at a higher level during the stages of leaf expansion and vigorous growth, and zeatin riboside (ZR) and gibberellic acid (GA) gradually decreased with an increase in water deficit. At the leaf-shedding stage, the concentration of abscisic acid (ABA) dramatically increased, and the ratio of ABA to growth-promoting hormones increased to a high level, which indicated that the rate of leaf senescence and shedding was accelerated. At the stages of leaf expansion and vigorous growth, the actual efficiency of photosystem II (PSII) (ΦPSii) was downregulated with an increment in non-photochemical quenching (NPQ) under moderate water deficit. Excess excitation energy was dissipated, and the maximal efficiency of PSII (Fv/Fm) was maintained. However, with progressive water stress, the photo-protective mechanism was inadequate to avoid photo-damage; Fv/Fm was decreased and photosynthesis was subject to non-stomatal inhibition under severe water deficit. At the leaf-shedding stage, non-stomatal factors became the major factors in limiting photosynthesis under moderate and severe water deficits. In addition, the generation of O2•- and H2O2 in the leaves of Caragana was accelerated under moderate and severe water deficits, which caused an enhancement of antioxidant enzyme activities to maintain the oxidation-reduction balance. However, when the protective enzymes were insufficient in eliminating excessive reactive oxygen species (ROS), the activity of catalase (CAT) was reduced at the leaf-shedding stage. Taken all together, Caragana has strong drought resistance at the leaf expansion and vigorous growth stages, but weak drought resistance at the leaf-shedding stage.

Microbial function regulates the effect of vegetation restoration on the contribution of biocrusts to soil respiration in drylands

Abstract Biocrusts are special components of dryland ecosystems and play important roles in ecosystem carbon cycles. Vegetation restoration not only affects carbon storage but also changes the characteristics of biocrusts. However, how vegetation restoration influences the contribution of biocrusts to soil carbon cycling in dryland ecosystems is poorly understood. Using continuous field measurements combined with metagenomic shotgun sequencing, we explored the effect and regulatory mechanisms of Caragana korshinskii vegetation restoration on the contribution of biocrusts to total soil respiration. We found that vegetation restoration increased the contribution of biocrusts to total soil respiration, with the biocrust contribution increasing from −5.6% for mixed biocrusts in a typical steppe to 17.1%, 18.1% and 19.6% for cyanobacteria–algae, lichen and moss biocrusts, respectively, in a Caragana korshinskii vegetation restoration area. The driving factors for total soil respiration changed from solely soil temperature to soil temperature and moisture after vegetation restoration. In contrast, the driving factors for soil respiration estimated for biocrust layers changed from precipitation alone to soil temperature and precipitation after vegetation restoration. We reveal that changes in microbial functional structure play important roles in regulating the effect of vegetation restoration and biocrusts on soil respiration. In addition, vegetation restoration also increases the microbial activity in biocrusted soils. This calls for an improved understanding of the effects of biocrusts on soil respiration under vegetation restoration scenarios to advance our ability to evaluate soil carbon releases from dryland ecosystems. Read the free Plain Language Summary for this article on the Journal blog.