Search Results (81)

The unique characteristics of desert vegetation, such as different leaf morphology, discrete canopy structures, sparse and uneven distribution, etc., pose significant challenges for remote sensing-based estimation of fractional vegetation cover (FVC). The Unmanned Aerial Vehicle (UAV) system can accurately distinguish vegetation patches, extract weak vegetation signals, and navigate through complex terrain, making it suitable for applications in small-scale FVC extraction. In this study, we selected the floodplain fan with Caragana korshinskii Kom as the constructive species in Hatengtaohai National Nature Reserve, Bayannur, Inner Mongolia, China, as our study area. We investigated the remote sensing extraction method of desert sparse vegetation cover by placing samples across three gradients: the top, middle, and edge of the fan. We then acquired UAV multispectral images; evaluated the applicability of various vegetation indices (VIs) using methods such as supervised classification, linear regression models, and machine learning; and explored the feasibility and stability of multiple machine learning models in this region. Our results indicate the following: (1) We discovered that the multispectral vegetation index is superior to the visible vegetation index and more suitable for FVC extraction in vegetation-sparse desert regions. (2) By comparing five machine learning regression models, it was found that the XGBoost and KNN models exhibited relatively lower estimation performance in the study area. The spatial distribution of plots appeared to influence the stability of the SVM model when estimating fractional vegetation cover (FVC). In contrast, the RF and LASSO models demonstrated robust stability across both training and testing datasets. Notably, the RF model achieved the best inversion performance (R² = 0.876, RMSE = 0.020, MAE = 0.016), indicating that RF is one of the most suitable models for retrieving FVC in naturally sparse desert vegetation. This study provides a valuable contribution to the limited existing research on remote sensing-based estimation of FVC and characterization of spatial heterogeneity in small-scale desert sparse vegetation ecosystems dominated by a single species. Full article

Information on the effects of differences in root and soil properties on Saturated hydraulic conductivity (K_s) is crucial for estimating rainfall infiltration and evaluating sustainable ecological development. This study selected typical grass shrub composite plots widely distributed in hilly and gully areas of the Loess Plateau: Caragana korshinskii, Caragana korshinskii and Agropyron cristatum (fibrous root), and Caragana korshinskii and Artemisia gmelinii (taproot). Samples were collected at different distances from the base of the shrub (0 cm, 50 cm), with a sampling depth of 0–30 cm. The constant head method is used to measure the K_s. The K_s decreased with increasing soil depth. Due to the influence of shrub growth, there was significant spatial heterogeneity in the distribution of K_s at different positions from the base of the shrub. Compared to the sample location situated 50 cm from the base of the shrub, it was observed that in a single shrub plot, the K_s at the base were higher, while in a grass shrub composite plot, the K_s at the base were lower. Root length density, >0.25 mm aggregates, and organic matter were the main driving factors affecting K_s. The empirical equation established by using principal component analysis to reduce the dimensions of these three factors and calculate the comprehensive score was more accurate than the empirical equation established by previous researchers, who considered only root or soil properties. Root length density and organic matter had significant indirect effects on K_s, reaching 52.87% and 78.19% of the direct effects, respectively. Overall, the composite plot of taproot herbaceous and shrub (Caragana korshinskii and Artemisia gmelinii) had the highest K_s, which was 82.98 cm·d⁻¹. The ability of taproot herbaceous plants to improve K_s was higher than that of fibrous root herbaceous plants. The research results have certain significance in revealing the influence mechanism of the grass shrub composite on K_s. Full article

Calorific value and moisture content are the key indices to evaluate Caragana pellet fuel’s quality and combustion characteristics. Calorific value is the key index to measure the energy released by energy plants during combustion, which determines energy utilization efficiency. But at present, the determination of solid fuel is still carried out in the laboratory by oxygen bomb calorimetry. This has seriously hindered the ability of large-scale, rapid detection of fuel particles in industrial production lines. In response to this technical challenge, this study proposes using hyperspectral imaging technology combined with various chemometric methods to establish quantitative models for determining moisture content and calorific value in Caragana korshinskii fuel. A hyperspectral imaging system was used to capture the spectral data in the 935–1720 nm range of 152 samples from multiple regions in Inner Mongolia Autonomous Region. For water content and calorific value, three quantitative detection models, partial least squares regression (PLSR), random forest regression (RFR), and extreme learning machine (ELM), respectively, were established, and Monte Carlo cross-validation (MCCV) was chosen to remove outliers from the raw spectral data to improve the model accuracy. Four preprocessing methods were used to preprocess the spectral data, with standard normal variate (SNV) preprocessing performing best on the quantitative moisture content detection model and Savitzky–Golay (SG) preprocessing performing best on the calorific value detection method. Meanwhile, to improve the prediction accuracy of the model to reduce the redundant wavelength data, we chose four feature extraction methods, competitive adaptive reweighted sampling (CARS), successive pojections algorithm (SPA), genetic algorithm (GA), iteratively retains informative variables (IRIV), and combined the three models to build a quantitative detection model for the characteristic wavelengths of moisture content and calorific value of Caragana korshinskii fuel. Finally, a comprehensive comparison of the modeling effectiveness of all methods was carried out, and the SNV-IRIV-PLSR modeling combination was the best for water content prediction, with its prediction set determination coefficient $\left(R_P^2\right)$, root mean square error of prediction (RMSEP), and relative percentage deviation (RPD) of 0.9693, 0.2358, and 5.6792, respectively. At the same time, the moisture content distribution map of Caragana fuel particles is established by using this model. The SG-CARS-RFR modeling combination was the best for calorific value prediction, with its $R_P^2$, RMSEP, and RPD of 0.8037, 0.3219, and 2.2864, respectively. This study provides an innovative technical solution for Caragana fuel particles’ value and quality assessment. Full article

The purpose of this study was to explore the effects of co-ensiling Caragana korshinskii with different proportions of oat grass on silage fermentation quality, chemical composition, in situ rumen degradability and in vitro rumen fermentation characteristics. C. korshinskii and oat grass were mixed at different ratios of 100:00, 90:1, 80:2, 70:30, 60:40 and 50:50. Each ratio of mixture was ensiled for 7, 14, 30, 45 and 60 days at room temperature (25 °C), with 30 bags per ratio, for a total of 180 bags. We further investigated the dynamic profiles of the bacterial community during ensiling and in vitro rumen fermentation. The results showed that co-ensiling C. korshinskii and oat grass decreased the pH values and increased the content of lactic acid and acetic acid compared with ensiling C. korshinskii alone. C. korshinskii ensiled with oat grass at a ratio of 70:30 (70% C. korshinskii) showed the best fermentation quality, which was related to higher relative abundance of Lactobacillus and Weissella. The silage with the ratio of 70:30 (70% C. korshinskii) showed higher dry matter digestibility and the more production of gas and total volatile fatty acids, compared with fresh C. korshinskii. In conclusion, C. korshinskii co-ensiled with oat grass at a ratio of 70:30 could enhance the fermentation quality and digestibility of C. korshinskii. Full article

Caragana korshinskii, a protein-rich feed plant in arid regions, lacks comprehensive nutrient analysis. This study compared the chemical composition of its five parts (leaves, bark, twigs, branches, and stems) and evaluated protein quality through amino acid profiling and enzymatic digestion. Results showed that leaves and bark contained higher crude protein (16.6–18.6%) than stems (6.8%), with fiber components (NDF > 81% and ADF > 65%) contributing to structural rigidity. Aspartic acid dominated caragana proteins, while bark and twigs exhibited elevated proline levels. CNCPS analysis revealed leaves contained 53.3% intermediately degradable protein (PB₂) versus 11.6% non-protein nitrogen (PA), whereas bark and twigs had 38.8% and 45.8% PA, respectively. Despite higher PA content, bark and twigs demonstrated superior in vitro protein digestibility (73.2% and 67.4%) compared to leaves (61.2%). The findings established baseline nutritional data, highlighting part-specific variations in protein characteristics critical for optimizing caragana’s application in animal feed technology within resource-limited ecosystems. Full article

Caragana korshinskii Kom. (CKB), widely cultivated in Inner Mongolia, China, has potential for silage feed development due to its favorable nutritional characteristics, including a crude protein content of 14.2% and a neutral detergent fiber content below 55%. However, its vascular bundle fiber structure limits the efficiency of lactic acid conversion and negatively impacts silage quality, which can be improved through mechanical crushing. Currently, conventional crushing equipment generally suffers from uneven particle size distribution, high energy consumption, and low processing efficiency. In this study, a layered aggregate model was constructed using the discrete element method (DEM), and the Hertz–Mindlin with Bonding contact model was employed to characterize the heterogeneous mechanical properties between the epidermis and the core. Model accuracy was enhanced through reverse engineering and a multi-particle-size filling strategy. Key parameters were optimized via a Box–Behnken experimental design, with a core normal stiffness of 7.37 × 10¹¹ N·m⁻¹, a core shear stiffness of 9.46 × 10¹⁰ N·m⁻¹, a core shear stress of 2.52 × 10⁸ Pa, and a skin normal stiffness of 4.01 × 10⁹ N·m⁻¹. The simulated values for bending, tensile, and compressive failure forces had relative errors of less than 10% compared to experimental results. The results showed that rectangular hammers, due to their larger contact area and more uniform stress distribution, reduced the number of residual bonded contacts by 28.9% and 26.5% compared to stepped and blade-type hammers, respectively. Optimized rotational speed improved dynamic crushing efficiency by 41.3%. The material exhibited spatial heterogeneity, with the mass proportion in the tooth plate impact area reaching 43.91%, which was 23.01% higher than that in the primary hammer crushing area. The relative error between the simulation and bench test results for the crushing rate was 6.18%, and the spatial distribution consistency reached 93.6%, verifying the reliability of the DEM parameter calibration method. This study provides a theoretical basis for the structural optimization of crushing equipment, suppression of circulation layer effects, and the realization of low-energy, high-efficiency processing. Full article

Caragana korshinskii, a key species in China’s Grain for Green Project on the Loess Plateau, is effective in enhancing soil C sequestration. However, whether its contribution to SOC (soil organic carbon) stability persists over multi-decadal restoration chronosequences remains unclear. Using the time–space substitution method, we investigated the SOC fractions (POC, particulate organic C, and MAOC, mineral-associated organic C) dynamics across soil depths (0–10, 10–30, and 30–60 cm) in a 40-year chronosequence of C. korshinskii restoration, which is located in a comprehensive managed watershed on the Loess Plateau, China. The results showed that the C. korshinskii restoration chronosequence improved soil C sequestration at different scales compared to abandoned sites. In the middle phase (10–30 years), the concentration of SOC peaked at 35.88 g/kg, exceeding natural grassland (32.33 g/kg). Above- and belowground biomass accumulation drove SOC enhancement. POC as transient C inputs, and MAOC through mineral interactions, reach a peak at 7.98 g/kg which shows the greatest increase (276.81%). In the subsequent phase (after 30 years), MAOC dominated SOC stabilization, yet SOC fractions declined overall. MAOC contribution to SOC stability plateaued at 20–30%, constrained by soil desiccation from prolonged root water uptake. C. korshinskii provides the optimal SOC benefits within 10–30 years of restoration, highlighting a trade-off between vegetation-driven C inputs and hydrological limits in arid ecosystems. Beyond 30 years, C. korshinskii’s high water demand reduced SOC sequestration efficiency, risking the reversal of carbon gains despite initial MAOC advantages. Full article

Climate change and intensified human activities have led to plant degradation and land desertification in desert areas, which seriously threaten ecological security. The establishment of the Caragana korshinskii plantation is considered to be one of the important means to improve the ecological environment in thealpine sandy region. This study focuses on Caragana korshinskii plantation in the alpine sandy region of the Qinghai–Tibet Plateau. Adopting a space-for-time substitution approach, six restoration chrono sequences were selected: 0 years, 5 years, 15 years, 25 years, 35 years, and 50 years. By investigating the variations in vegetation community composition and soil properties, we aim to elucidate the plant and soil system interactions under different restoration durations. The findings will clarify the stability evolution patterns of Caragana korshinskii plantation during desertification control and contribute to promoting green development strategies. The main conclusions of this study are as follows: With the passage of planting time, the plant biomass and species diversity of the Caragana korshinskii plantation community showed a trend of first increasing and then decreasing, reaching their peak in 25~35 years. Soil water content exhibited fluctuating trends, while soil organic matter showed progressive accumulation, demonstrating that Caragana korshinskii plantations effectively improved soil fertility. Community stability reaches its maximum (4.98) at 25 years. In summary, the Caragana korshinskii plantation are in an early stage of ecological secondary succession, with plant communities developing from simple to complex structures and gradually approaching, though not yet achieving a stable state. Full article

Desertification, which may lead to land degradation, is a significant global ecological issue. Biological soil crusts (BSCs) can play a role in sand fixation, carbon sequestration, and the improvement in soil functions in the ecological restoration of sandy soil. Therefore, elucidating the responses of BSCs to afforestation measures in alpine sandy areas is necessary to guide vegetation configuration in sandy ecosystems and enhance the effectiveness of sand fixation measures to prevent desertification. Herein, we determined the physicochemical properties and enzyme activities of bare sand (no crust) and algal and moss crusts collected from four sites subjected to different afforestation measures, including Salix cheilophila + Populus simonii (WLYY), Salix psammophila + S. cheilophila (SLWL), Artemisia ordosica + Caragana korshinskii (SHNT), and C. korshinskii (NT80) plantations. High-throughput sequencing was also employed to analyze bacterial community structure in BSCs. The results revealed that fine particle contents in algal and moss crusts were higher than in bare sand. During the succession from bare sand to algae to moss crust, their enzymatic activities and water and nutrient contents tended to increase. And the diversity of bacterial communities changed little in the SLWL sample points, while the richness showed a trend of first decreasing and then increasing, but bacterial community richness and diversity first decreased and then increased at the other sites. Among the four measures, SLWL enhanced nutrient contents, enzyme activities, and bacterial community richness and diversity in BSCs relatively more effectively. Alkaline-hydrolyzable nitrogen and soil organic matter were the key factors impacting bacterial community structures in BSCs under the four afforestation measures. From the perspective of BSCs, the results can provide a reference for the prevention and control strategies of other alpine sandy soils. Full article

Litter serves as a crucial source of soil nutrients in sandy land ecosystems. Soil enzyme activities and their stoichiometric ratios act as essential “bridges” linking microbial metabolism with nutrient cycling, thereby reflecting the availability of soil nutrients and the sensitivity to microbial substrate limitations. To investigate the effects of litter quality changes on soil nutrients, enzyme activities, and stoichiometric ratios in sandy land, leaf litter and surface soil were collected from four sand-fixing forests in the Mu Us Sandy Land, including YC (Corethrodendron fruticosum), NT (Caragana korshinskii), ZSH (Amorpha fruticose), and SL (Salix cheilophila). These samples were then used for indoor cultivation. Experiments with these four leaf litter types were carried out; one treatment with no litter added served as the control. Our aim was to systematically study the changing characteristics of enzyme activities related to soil carbon, nitrogen, and phosphorus with different litter inputs. The results indicate the following: (1) Compared to the control treatment with no litter added (CK), the addition of all four types of litter significantly increased soil organic carbon, total nitrogen, and alkaline nitrogen contents. The addition of NT and YC litter significantly increased dissolved organic carbon, microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN). (2) The addition of the four types of litter had different effects on the soil enzyme activity, showing increasing trends overall. A chemical analysis of the enzyme activity revealed that the soil was limited in nitrogen and phosphorus. After the addition of the ZSH, NT, and YC litter, the enzymatic C/P acquisition ratio (E_C/P) and enzymatic N/P acquisition ratio (E_N/P) decreased significantly, alleviating the limitation of phosphorus. After the addition of the NT litter, the enzymatic C/N acquisition ratio (E_C/N) increased significantly, alleviating the limitation of soil nitrogen. (3) A correlation analysis showed that the soil nutrients had varying degrees of correlation with enzyme activity and their stoichiometric ratio. The redundancy analysis results show that MBN, TN, MBC/MBN, organic carbon, and available nitrogen were key factors influencing soil enzyme activity and stoichiometric ratios. These results provide a reference for nutrient cycling during sandy soil restoration, and they provide essential data support for the development of fragile ecosystem models in the context of global change. Full article

The accurate modeling of seed motion characteristics is crucial for optimizing seed-metering devices in agricultural machinery. This study investigated the physical properties and contact parameters of coated Caragana korshinskii seeds through a combined approach of calibration experiments and verification tests. Physical experiments were conducted to measure basic parameters including seed dimensions, density, moisture content, and angle of repose. The Plackett–Burman experimental design was employed to screen significant parameters affecting seed motion, followed by the Path of Steepest Ascent method and Response Surface Methodology to establish optimal parameter combinations. Results identified three key parameters: seed-to-seed coefficient of restitution (0.221), seed-to-seed static friction coefficient (0.337), and seed-to-aluminum static friction coefficient (0.117). Verification tests using a 4BQD-40 broadcast seeder demonstrated good agreement between simulation and physical experiments, with relative errors of 1.56% for the angle of repose. Seeding efficiency showed consistent results between calibration (354 g/min) and verification tests (347 g/min), while breakage rates remained within acceptable ranges (2.3% predicted vs. 4.1% actual). The established parameter set provides a reliable foundation for discrete element simulation of coated Caragana korshinskii seed motion in metering devices, contributing to the optimization of seeding equipment design. Full article

This study aimed to explore the impacts of Lactiplantibacillus plantarum (L), Saccharomyces cerevisiae (Y), tannase-producing bacteria (D), cellulase (M), and their combined treatment (L + Y + D + M) on the sensory quality, chemical composition, silage quality, and microbial community of Caragana korshinskii. In light of the scarcity of research on the use of tannase-producing bacteria, Lactiplantibacillus plantarum, Saccharomyces cerevisiae, and cellulase as composite silage additives in the utilization of desert shrubs as feed resources, this study centers on this area and endeavors to offer a novel theoretical foundation for relevant fields. Different microorganisms and enzymes were individually added to 500 g of Caragana korshinskii, and anaerobic fermentation was carried out in an incubator at 40 °C for 14 days. The results show that compared to the control group (CK) without any additives, the sensory evaluation of all treatments improved, with the L + Y + D + M treatment being the best (p < 0.05). All treatments reduced the contents of acid detergent fiber, neutral detergent fiber, and tannin (p < 0.05), while increasing the content of crude protein and relative feeding value (p < 0.05), with the L + Y + D + M treatment showing the most significant effect (p < 0.05). Lactic acid levels significantly increased (p < 0.05) and the pH significantly decreased (p < 0.05) in all treatments, with the L + Y + D + M treatment outperforming the other treatments (p < 0.05). The L + Y + D + M treatment increased the abundance of Lactiplantibacillus plantarum and Weissella (p < 0.05), significantly reduced harmful microbial abundance and diversity (p < 0.05), and improved the microbial community structure in silage. In summary, the addition of Lactiplantibacillus plantarum (L), Saccharomyces cerevisiae (Y), tannase-producing bacteria (D), cellulase (M), and their combined treatment (L + Y + D + M) can promote the silage-related characteristics of Caragana korshinskii, with the L + Y + D + M treatment performing better compared to the other treatments. The research shows that the compound bacterial and enzymatic preparation is more effective than the single-component. The components exert synergistic effects and can effectively enhance the quality aspects of silaged Caragana korshinskii. This research provides theoretical underpinnings for the utilization of Caragana korshinskii as feedstuff. This application has the potential to alleviate feed scarcity, reduce reliance on traditional feed, enhance the stability and diversity of the feed supply system, and thereby drive the development of the animal husbandry industry. Full article

Desertification severely impacts soil environments, necessitating effective control measures to improve sandy soil. On the alpine sandy land of Gonghe Basin, taking bare land containing mobile sand dunes (LD) as a reference, surface soil undergoing four afforestation measures, namely Salix cheilophila + Populus simonii (WLYY), Salix psammophila + Salix cheilophila (SLWL), Artemisia ordosica + Caragana korshinskii (SHNT), and Caragana korshinskii (NT80), was studied, with soil physicochemical properties and enzyme activity measured and the bacterial community structure analyzed using Illumina high-throughput sequencing. Compared to LD, all four afforestation measures significantly reduced the sand content, while increasing soil total carbon, total nitrogen, organic matter, alkali-hydrolyzable nitrogen, and available potassium. WLYY, SLWL, and SHNT significantly increased the surface soil total phosphorus and total potassium. Catalase, sucrase, urease, and alkaline phosphatase activities significantly increased under all four measures. Among them, the highest improvements were observed under SLWL, followed by WLYY. All treatments increased soil bacterial community richness, exhibiting significantly different bacterial community compositions to those in LD. Total phosphorus was the key physicochemical factor affecting the soil bacterial community structure, while enzyme activity was significantly correlated with the relative abundance of most major bacterial phyla. All measures improved the surface soil environment, with SLWL demonstrating the best improvement. The results provide valuable reference for sand prevention and control strategies in alpine sandy areas and offer a theoretical basis for the ecological restoration of sandy soil microenvironments. Full article

This study focuses on developing a finite element model for Caragana korshinskii Kom. branches and calibrating the necessary parameters. Using Caragana korshinskii Kom. branches in full bloom as the subject, we established a finite element model with ABAQUS and analyzed the relationship between the shear force and displacement. The Johnson–Cook model was employed to create a finite element shear model for Caragana korshinskii Kom. branches and to calibrate its parameters. Plackett–Burman and climbing tests were conducted to identify key parameters influencing the shear mechanical model of Caragana korshinskii Kom. branches, specifically the yield stress and strain. This included the strengthening index and fracture strain. Through central composite design experiments, the optimal parameters for the shear model of Caragana korshinskii Kom. branches were identified: a yield stress of 18.65 MPa, a strain strengthening index of 0.59, and a fracture strain of 0.54. The results indicated that the maximum error in the simulated shear force values for Caragana korshinskii Kom. branches of varying diameters was 9.68%. Additionally, the difference between the simulated and actual tensile force values was 1.7%. These findings indicate that the calibrated finite element model is accurate and effective in simulating the failure behavior of Caragana korshinskii Kom. branches, providing a valuable tool for optimizing cutting and harvesting processes. Full article

The Gobi Desert is one of the harsh terrestrial ecosystems distributed on the Mongolian Plateau and northwest China. Water is the key restricting environmental factor for the Gobi Desert plants’ growth. Exploring the annual dynamic of water sources for the vulnerable plants in the Gobi Desert helps to understand their adaptation to the arid climate and is fundamental for their conservation, e.g., the vulnerable plant Ammopiptanthus mongolicus (Maxim. ex Kom.) S. H. Cheng. The water source of the dominant and companion shrubs in a Gobi Desert A. mongolicus community was determined by comparing the δD and δ¹⁸O values of their xylem water and different layers of soil water using the MixSIAR model from spring to autumn over two years. The results showed that A. mongolicus mainly utilized 50–150 cm of middle and deep soil water. However, it also used 10 or 25 cm of surface soil water after heavy rains in the early spring and moderate rains in the autumn of 2021 and after heavy rains in the summer of 2022. Three companion shrubs (Nitraria sphaerocarpa Maxim, Caragana korshinskii Kom, and Convolvulus tragacanthoides Turcz.) had similar main water sources, competing for relatively reliable deep soil water with the dominant A. mongolicus during droughts in 2021 and 2022. Moreover, A. mongolicus utilized more deep soil water in 2021 with less rain. However, C. tragacanthoides used more shallow soil water during the growing season of 2022 with more rain. Therefore, four xerophytic shrubs in the A. mongolicus community utilized soil water in different layers based on their ability to adapt to the annual fluctuation of rain in the Gobi Desert. Full article