Search Results (11)

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

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

Accurately estimating the volume of woody vegetation is critical for assessing fuel characteristics and associated wildfire risks in shrublands. However, few studies have investigated the branch volume of multi-stemmed shrubs, a dominant life form in wildfire-prone drylands. This study predicts branch volume using the inflection point of branch diameter. This inflection point, identified using the “Segmented” package in R, marks the transition from a gradual decrease to a significant reduction in diameter along the stem. The volume of branch segment above this point is calculated as a cone, and below it, a cylinder. We validated this method on various species such as Caragana korshinskii, Salix psammophila, and Vitex negundo. Good estimations were achieved with an average 19.2% bias relative to reference branch volumes, outperforming conventional methods that subjectively treated the whole branch as either a cylinder (96.9% bias) or a cone (−34.4% bias). We tallied branches by basal diameter and provided inventories for easily locating the inflection point, as well as using two-way branch volume tables for rapid volume predictions in shrubland. In general, we developed an effective method for estimating branch volumes of multi-stemmed shrubs, enabling its application to larger-scale shrubland volumetric prediction. This advancement supports wildfire hazard assessment and informs decision-making in fuel treatments. Full article

The Loess Plateau region of China suffers from severe soil erosion, and the selection of effective slope-protection vegetation is essential to prevent soil and water loss. This study focused on individual plants of common species in the Loess Plateau, such as Caragana korshinski Kom., Hippophae rhamnoides Linn., Pinus tabuliformis Carr., Robinia Pseudoacacia Linn., Populus tomentosa Carr., Prunus armeniaca Lam. The root spatial distribution, geometric morphology, and fractal characteristics of these plants were measured using the whole-root-excavation method, and the vertical pull-out force of their root systems was quantified using the in situ whole-plant root-pulling method. The results showed that H. rhamnoides dominates in the vertical spatial distribution of its root system through a larger number of inclined roots. C. korshinskii, P. tomentosa, R. pseudoacacia, and P. armeniaca dominate in the horizontal spatial distribution of their root systems through a greater number of horizontal roots. P. tabuliformis, on the other hand, achieves a relatively balanced distribution in both horizontal and vertical spaces through its well-developed taproot and numerous lateral roots. In terms of the geometric morphology and fractal characteristics of their root systems, H. rhamnoides and C. korshinskii exhibit a larger number of fine roots and complex branching, resulting in a higher total-root length, total-root surface area, and root fractal dimension. The soil-stabilizing ability of H. rhamnoides, C. korshinskii, and R. pseudoacacia was stronger, mainly influenced by their total-root length, total-root surface area, and inclined root quantity, and these species can be prioritized as typical vegetation for soil and water conservation in the construction of Loess Plateau vegetation. From the perspective of slope stabilization and soil conservation alone, we strongly recommend planting shrub vegetation in the Chinese Loess Plateau. Full article

To realize the reduction in cutting force and guarantee pruning section quality in the pruning and stubble work of Caragana korshinskii (C.K.), a concentric curvilineal edge sliding cutter was proposed and the related cutting characteristics were studied. The impacts of branch diameter (D), cutting speed (${\mathrm{V}}_{\mathrm{c}}$), blade wedge angle ($\mathsf{\beta }$), cutting clearance ($\mathrm{c}$) and moisture content (W) on peak torque (T) and cutting energy (E) with this cutter were explored in single-factor tests. On the basis of the Box—Behnken principle, a multi-factor test was further conducted based on the single-factor tests with ${\mathrm{V}}_{\mathrm{c}}$, $\mathsf{\beta }$ and c as influencing factors and with T and E as targets, and a regression model was established. Test results indicate that the peak torque (T) increases with the increase in D and $\mathsf{\beta }$ and reduces with the growth of ${\mathrm{V}}_{\mathrm{c}}$ and W; with the increase in $\mathrm{c}$, it reduces first and then rises; the cutting energy (E) increases with the growth of D and $\mathsf{\beta }$, declines with the increase in W and diminishes first and then rises with the increase in ${\mathrm{V}}_{\mathrm{c}}$ and $\mathrm{c}$. The optimal parameter combination of the regression model was obtained with ${\mathrm{V}}_{\mathrm{c}}$ of 2.16 rad/s, $\mathsf{\beta }$ of 20$°$ and $\mathrm{c}$ of 1.0 mm, which resulted in a T of 17.25 N·m and P of 7.03 J. The discrepancies between the observed and forecasted values for T and E are 0.87% and 5.004%. New cutting tool and data support for the development of subsequent C.K. branch stubble equipment can be obtained with this new sliding cutter. Full article

Soil erodibility by wind is not only affected by the basic physical and chemical properties of the soil but also the functional traits of plant roots. However, the roles played by the morphological and architectural traits of plant roots on wind-based soil erodibility in the Bashang region of China are still unclear. Therefore, two typical tree shelterbelts and two shrub shelterbelts in the Bashang region were selected to assess and determine how the root traits affected soil erodibility, especially characteristics such as dry aggregate, soil organic matter, and shearing resistance. The results showed that the soil dry aggregates of the two shrubs (Lycium barbarum and Caragana korshinskii) had higher geometric mean diameters (0.40 ± 0.03 mm) and mean weight diameters (0.82 ± 0.08 mm) but a lower erodible fraction (81.81% ± 1.62%) compared to the two trees (Populus simonii and Ulmus pumila). The mean weight diameter (MWD_d) and geometric mean diameter (GMD_d) of dry soil aggregates were negatively correlated with the soil erodible fraction (EF_d), but these parameters were positively correlated with shearing resistances. The specific root length (SRL) and surface area (SSA) of plant roots were positively correlated with the GMD_d of the soils, though these two parameters negatively correlated with the soil erodible fraction. The root branching intensity (BI) was negatively correlated with the MWD_d and GMD_d of dry soil aggregates. The total carbon or nitrogen of the soil displayed significantly positive and negative correlations to the geometric mean diameters and erodible fractions of the soils, respectively. The findings showed that plant roots with higher SRLs, as well as lower root diameters and BIs, played positive key roles in soil stability. The same applied to soils with higher nitrogen, carbon, and water content. The results from this study suggest that L. barbarum is superior to the other three species based on root traits and wind erosion resistance. These findings provide critical information for selecting plants for the sustainable management of windbreak and sand fixation. Full article

To solve the problems of poor sawing surface quality, severe blade wear and high power consumption caused by unreasonable working parameters in the process of Caragana korshinskii (C.K.) stumping, this study explored the effects of branch diameter (D), sawing speed $\left(v_c\right)$, feeding speed $\left(v_f\right)$, cutting inclination (α), number of circular saw teeth (T) and moisture content (M) on sawing power consumption (P) and sawing surface quality (A) through a single-factor test using a homemade branch sawing bench. Based on the Box–Behnken design principle, a multi-factor test was carried out based on a single-factor test with $v_c$,$v_f$, α and T as influencing factors and with P and A as targets, establishing a regression model. The test results show that the sawing power consumption (P) increases with increasing D, decreases with increasing M, and decreases first and then increases with increasing $v_c$, $v_f$, α and T; the sawing surface quality (A) increases first and then decreases with increasing D, increases with increasing M, and first increases and then decreases with increasing $v_c$, $v_f$, α and T. The optimum combination of parameters for the regression model was obtained with $v_c$ of 45.24 m/s, $v_f$ of 0.34 m/s, α of 10° and T of 100, which resulted in the P of 177.46 J and A of 85.87%. The errors between the predicted and actual values of P and A are 3.1% and 6%, respectively. The study can provide information to support the development of subsequent C.K. stubble equipment. Full article

In order to investigate the cutting mechanical characteristics of Caragana korshinskii (C.k.) branches and explore the optimal combination of cutting parameters to support the subsequent equipment development, this paper explores the relationship between branch diameter D, average cutting speed v, wedge angle β, slip cutting angle α, cutting height h, cutting gap t, moisture content M and peak cutting force by using a homemade swing-cut branch cutting test bench with peak cutting force of branches as the target value under unsupported and supported cutting methods, respectively, through single-factor tests. Based on the single-factor test, v, β, α and t were selected as the test factors, and a multi-factor test was conducted with the peak cutting force as the target. Test result: The best combination of unsupported cutting in the range of multi-factor test is v for 3.315 m·s⁻¹, β for 20°, α for 20°, when the peak cutting force is 95.690 N. Supported cutting multi-factor test range to get the best combination of v for 3.36 m·s⁻¹, β for 20°, α for 20°, t for 1.38 mm, when the peak cutting force is 53.082 N. The errors of the predicted peak cutting force and the measured peak cutting force of the obtained model were 1.3% and 3.9%, respectively, which prove that the cutting parameters were optimized reliably. This research can provide a theoretical basis for subsequent development the C.k. harvesting equipment. Full article

The traditional heat balance method for measuring plant sap flow (SF) becomes troublesome and uneconomic for multibranched shrub species if all their stems are used for the measurement. The objectives of this study were to explore specific relationships between stem-scale SF and plant morphological traits and then to scale up SF measurements from the stem scale to the individual scale for Caragana korshinskii Kom., a dominant shrub species on the Chinese Loess Plateau. Sap flow was measured for twenty-one stems from three representative individuals from July to September 2018 during the rainy season. The results indicated that the stem-scale SF in C. korshinskii presented a positive linear correlation with the stem base diameter (SBD), stem length (SL), primary branch numbers in the stem (PBN), and estimated stem biomass (W). The SBD-based statistical models performed well in estimating the stem-scale SF, with an R² value of 0.9726 and root mean squared error (RMSE) of 2.5389 g h⁻¹. Over the canopy projection area, the individual-scale transpiration flows for the three selected C. korshinskii were 1.91, 1.10, and 1.59 mm·d⁻¹. In addition, stem-scale SF was positively and linearly correlated with air temperature, photosynthetically active radiation, vapor pressure deficit, reference crop evapotranspiration, and variable transpiration. This study sheds light on morphological and meteorological influences on stem-scale SF and has made contributes to the accurate and rapid estimation of the plant sap flow from easily available morphological traits for multibranched shrub species in semiarid regions. Limitations, however, may exist for the established model when it is used to estimate SF of C. korshinskii during the water-limited dry season. Our study deserves further exploration of a more general model to have a better estimation of SF for C. korshinskii in both dry and rainy seasons. Full article

The quantification of above-ground biomass is based on the calculation of carbon storage, which is important for the balance of carbon cycling. However, the allometric models of shrubs for calculating the above-ground biomass of shrubs in the Loess Plateau are scarce. In order to solve this issue, this study analyzed some highly correlated variables, including height (H), branch diameters (D), canopy volume (C_v), canopy area (C_a), and then built a regression model to predict the above-ground biomass in two common shrubs (Caragana korshinskii and Sophora viciifolia) in the Loess Plateau, China. The results show that the above-ground biomass of these two shrubs can be accurately predicted by H and D, and then we can use allometric model (y = ax^b) to calculate shrub above-ground biomass (including leaf biomass and branch biomass). Furthermore, the correlation between leaf biomass and branch biomass in Caragana korshinskii and Sophora viciifolia indicates that the components of above-ground biomass are closely related to each other. In addition, there is a strong linear relationship (p < 0.01) between the observed and estimated biomass values, which confirms the data accuracy of the above-ground biomass estimation models. In summary, these two biomass estimation models provide an accurate way to estimate the quantification of carbon for shrubs in the Loess Plateau. Full article

To exploit the drought-resistant Caragana species, we performed a comparative study of the plastomes from four species: Caragana rosea, C. microphylla, C. kozlowii, and C. Korshinskii. The complete plastome sequence of the C. rosea was obtained using the next generation DNA sequencing technology. The genome is a circular structure of 133,122 bases and it lacks inverted repeat. It contains 111 unique genes, including 76 protein-coding, 30 tRNA, and four rRNA genes. Repeat analyses obtained 239, 244, 258, and 246 simple sequence repeats in C. rosea, C. microphylla, C. kozlowii, and C. korshinskii, respectively. Analyses of sequence divergence found two intergenic regions: trnI-CAU-ycf2 and trnN-GUU-ycf1, exhibiting a high degree of variations. Phylogenetic analyses showed that the four Caragana species belong to a monophyletic clade. Analyses of Ka/Ks ratios revealed that five genes: rpl16, rpl20, rps11, rps7, and ycf1 and several sites having undergone strong positive selection in the Caragana branch. The results lay the foundation for the development of molecular markers and the understanding of the evolutionary process for drought-resistant characteristics. Full article