Hippophae rhamnoides (family Elaeagnaceae) is a deciduous shrub that has become a uniquely advantageous species in the arsenic sandstone area of Inner Mongolia due to its well-developed root system and strong tillering ability. This study, by taking 10-year-old H. rhamnoides in the arsenic sandstone area as the research object and analyzing the morphological traits of their fine roots and their coordination within soil under different stubble heights (0, 10, 15, and 20 cm) and non-stubble treatment, aims to select the optimal stubble height that is most conducive to the rejuvenation of H. rhamnoides and thus improve the decline in the productivity of H. rhamnoides in this region. The results reveal significant differences in fine root and soil properties under different stubble heights (p < 0.05). Among different traits, fine root area density shows the highest total coefficient of variation, making it the most sensitive trait. Principal component analysis results indicate that after stubble treatment, the traits of H. rhamnoides fine roots center on high specific surface area (0.316) + high specific root length (0.312), shifting toward a resource-acquisition ecological strategy with the best foraging efficiency observed under a stubble height of 15 cm. Soil N:P and C:P can explain 66% and 61% of the root morphological traits strategies deployed during stubble treatment, respectively. Fine roots exhibit high adaptability to the breaking of phosphorus limitation and fixation of carbon and nitrogen.

In this paper, the fractal mechanism of soil improvement by vegetation was revealed by analyzing the soil characteristics under four typical vegetation types: Salix cheilophila, Caragana korshinskii, Hippophae rhamnoides, and Corethrodendron fruticosum in Mu Us Sandy Land. The results showed that (1) the soil of each vegetation type was mainly composed of sand (> 90%), and the content of clay and silt was less than 10%. CF had the least heterogeneity of soil particles in the 0-120 cm soil layer, HR was uniformly distributed in the 120-200 cm soil layer, and the change trend of particle composition in the 140-200 cm soil layer was consistent. (2) Soil fractal dimension (D) was positively correlated with soil clay and silt content, and negatively correlated with sand content. The generalized dimension spectrum D(q) decreases in the "S" type, and the sensitivity was higher in the region of q < 0, indicating that the particle distribution in the sparse area is more susceptible to disturbance. (3) HR had the best water holding capacity in the surface layer (0-40 cm) and deeper layer (120-200 cm), and the average soil water storage in 0-200 cm reached 791.61 mm (13.76% higher than CF). All vegetation had soil water deficit in specific soil layers, among which SC had water deficit in 20-30 cm, CK in 0-10 cm, HR in 60-80 cm, and CF in 180-200 cm soil layers (0.91 mm, 0.90 mm, 0.92 mm, and 0.93 mm). (4) HR significantly affected soil bulk density and porosity by increased silt and sand (P < 0.05). The fractal parameters of SC were significantly correlated with soil water content (P < 0.05). The pH of CK was a significant correlation with soil water storage (P < 0.01). CF soil particle composition and fractal parameters were significantly correlated with soil moisture content, bulk weight, and capillary porosity (P < 0.05). The study showed that HR achieves the best water retention and soil modification effect by optimizing soil structure and is the preferred vegetation for ecological restoration of the Mu Us Sandy Land.

This study aimed to clarify the effects of stumping on preferential flow in the understory soils of Hippophae rhamnoides and to assess appropriate stumping height for optimization of preferential flow. Root properties, soil properties, and preferential flow for different H. rhamnoides stump heights (0, 10, 15, 20 cm, and no-stumping, labeled conditions S1, S2, S3, S4, and CK, respectively) were studied using in situ dye-tracing and laboratory analysis. The results showed that stumping significantly increased preferential flow development. This effect was maximized in condition S3, with dye-tracing coverage (DC) of 36.77%, maximum dye depth (MaxD) of 40.02 cm, uniform infiltration depth (Unifr) of 14.28 cm, preferential flow ratio (PF fr ) of 23.85%, and length index (LI) of 96.72%. In terms of root length density (RLD), root mass density (RMD), root surface area density (RSAD), soil water content (SWC), soil total porosity (TP), mean weight diameter (MWD), and soil organic matter (SOM), the conditions were ranked S3>S2>S1>S3>CK; for root average diameter (RAD), they were ranked S3<S2<S1<S4<CK. Structural equation modeling showed that DC was affected directly by TP, MWD, and SWC and indirectly by RAD, RLD, RMD, RSAD, and SOM, explaining up to 89.1% of the variance. Thus, stumping of H. rhamnoides affected soil properties through the mechanism of root development, thereby improving preferential flow development in the soil and soil infiltration. The optimal stump height was 15 cm. These findings are critical for vegetation recovery and for prevention and control of soil erosion in feldspathic sandstone areas.

This study was aimed to clarify the effects of stumping on root and leaf traits as well as the tradeoffs and synergies of decaying Hippophae rhamnoides in feldspathic sandstone areas, and to select the optimal stump height that contributed to the recovery and growth of H. rhamnoides. variations and coordination between leaf traits and fine root traits of H. rhamnoides were studied at different stump heights (0, 10, 15, 20 cm, and no stumping) in feldspathic sandstone areas. All functional traits of the leaves and roots, except the leaf C content (LC) and the fine root C content (FRC), were significantly different among different stump heights. The total variation coefficient was the largest in the specific leaf area (SLA), which is therefore the most sensitive trait. Compared to non-stumping, SLA, leaf N content (LN), specific root length (SRL) and fine root N content (FRN) all improved significantly at stump height of 15 cm, but leaf tissue density (LTD), leaf dry matter content (LDMC), leaf carbon to nitrogen ratio (LC : LN), fine root tissue density (FRTD), fine root dry matter content (FRDMC) and fine root carbon to nitrogen ratio (FRC : FRN) all decreased significantly. The leaf traits of H. rhamnoides at different stump heights follow the leaf economic spectrum, and the fine roots show a similar trait syndrome to the leaves. SLA and LN are positively correlated with SRL and FRN and negatively with FRTD and FRC : FRN. LDMC and LC : LN are positively correlated with FRTD and FRC : FRN, and negatively correlated SRL and RN. The stumped H. rhamnoides changes to the ‘rapid investment–return type’ resource trade-offs strategy, and the growth rate is maximized at the stump height of 15 cm. Our findings are critical to the prevention and control of vegetation recovery and soil erosion in feldspathic sandstone areas.

Background Fine roots are vital to a plant’s ability to absorb water and nutrients. Stumping is a practice that may encourage fine root growth and the rapid recovery of decaying Hippophae rhamnoides plants. However, the effect of stumping on the fine roots and physiological indices is still unknown. The differential indices between stumped forests and non-stumped forests must also be defined. Methods We recorded the changes in the fine roots of structure H. rhamnoides one year after stumping. Using single factor analysis of variance and general linear models we comprehensively analyzed the number of root tips and the plant’s growth and physiological indices in response to stumping. Partial least squares discriminant analysis (PLS-DA) was used to compare fine root growth and physiological indices with and without stumping in order to identify the differential indices. Results The proportion of root tips in the vertical layers at 30–40 cm and 40–50 cm and in the horizontal layers at 60–80 cm and 80–100 cm, increased after stumping by 1.85%, 2.60%, 1.96% and 4.32%, respectively. In the 0–50 cm soil layer, the fine root dry weight rose by 27.6% compared with the control, which was not significant. However, other indices were significantly different from the control. The proportions in the growth indices in the 30–40 cm and 40–50 cm layers increased after stumping. Stumping had a significant, negative effect on proline and malondialdehyde content, which dropped by 40.95% and 55.32%, respectively, indicating that the harms caused by these two chemicals was alleviated. Stumping had a significant positive effect on root activity and soluble sugar contents, which increased by 68.58% and 36.87%, respectively, and improved the growing ability of fine roots. PLS-DA revealed that malondialdehyde, soluble sugars, root density, and the number of root tips ranked from having the least to greatest effect on the classification of stumping and no-stumping. Conclusions The process of stumping may promote fine roots growth in H. rhamnoides , and is favorable for their longitudinal development. The fine root growing indices of H. rhamnoides responded positively to this process. Stumping promotes root activity and the creation of soluble sugar to maintain the growth and development of fine roots. It also inhibits the negative effects of proline and malondialdehyde on fine roots. Our study showed that the differential physiological indices were more important for classification than the differential growing indices.

Wukehudong Town in Damao Banner of Baotou, Inner Mongolia, has fragile ecosystems where grassland degradation, soil-water loss, soil desertification and other ecological problems are increasingly severe. Vegetational ecosystem restoration can effectively solve soil-water loss in this region and ensure ecoenvironmental safety. Given the severe deterioration of Caragana korshinskii forests in this region, we chose an experimental area in Wukehudong Town and targeted at perennial C. korshinskii forests. The plant height, canopy size and root growth of C. korshinskii at stubble heights of 0, 10 and 20 cm and under the control mode (CK) were consecutively observed and comprehensively analyzed. This study will theoretically underlie the scientific management of C. korshinskii forests in this region to achieve ecosystem restoration in a scientific way.The C. korshinskii forests after stumping all experienced over-compensationary growth, and the compensatory growth at the stubble height of 10 cm was excellent. Stumping significantly promoted root growth at different root grades, and the total root lengths at different root grades in the C. korshinskii forests at different stubble heights ranked as fine roots (57.73%) > thick roots (37.85%) > bone roots (4.42%). Comprehensive analysis shows stumping can significantly prolong the total root length of C. korshinskii, which maximizes at the stump height of 10 cm.In all, stumping promotes the renewal and rejuvenation of C. korshinskii. The characteristic indices of C. korshinskii at different stubble heights were analyzed using membership functions. Comprehensive evaluation showed the C. korshinskii at stumping height of 10 cm had the strongest renewing ability and grew and developed the best.

Background To solve the withering of Hippophae rhamnoides plantation in the feldspathic sandstone areas of Inner Mongolia and to promote the regeneration, rejuvenation, and sustainability of H. rhamnoides forests. Methods We stumped aging H. rhamnoides trees at the ground heights of 0, 10, 15, and 20 cm (S1, S2, S3, and S4, respectively) and utilized unstumped trees as the control (CK). We then analyzed the effects of the different stump heights on the roots and the root microenvironment of H. rhamnoides and the relationship between the roots and the root microenvironment in the stumped H. rhamnoides. Results The root fractal features, root branching rate, root length, root soluble proteins, soil moisture content, and soil nutrients among the different treatments were ranked as S3>S2>S1>S4>CK (P < 0.05). The root topological index, root proline, and malondialdehyde among the different treatments were ranked as S3<S2<S1<S4<CK (P < 0.05). The topological indices of S1, S2, S3, S4, and CK were 0.80, 0.86, 0.89, 0.94, and 0.98, respectively, and all were near 1. This result indicated a typical fishtail-shaped branching structure. The root length and root fractal dimensions were primarily affected by the positive correlation of the soil moisture content and the soil organic matter, and the root topological index was primarily affected by the negative correlation of the root proline. Root nutrients were dominant in the changes in the root architecture, while soil moisture and nutrients played supporting roles. These results indicated that stumping can promote plant root growth and root nutrient accumulation, thereby improving soil moisture and the soil nutrient distribution, and the S3 treatment had the greatest impact on the H. rhamnoides roots and root microenvironment. Therefore, the 15 cm stump height treatment should be implemented for withering H. rhamnoides in feldspathic sandstone areas to promote vegetation restoration.

Objectives This study explored the effects of different degradation gradients on bacterial diversity in the rhizospheric soils of herb plants. Methods The alpha diversity, species composition and correlations of bacterial communities in the rhizospheric soils of herb plants were studied using metagenomics 16SrDNA gene high-throughput sequencing. Results The diversity of bacterial communities in the rhizospheric soils of herb plants differed during the degradation of desert steppes. An analysis of bacterial community alpha diversity indices showed the bacterial diversity and species evenness of rhizospheric soils were best in moderately degraded desert steppes. Among all samples, a total of 43 phyla, 133 classes, 261 orders, 421 families, 802 genera and 1,129 species were detected. At the phylum level, the predominant bacterial phyla were: Actinobacteria, Proteobacteria, Acidobacteria, Gemmatimonadetes, Chloroflexi, Planctomycetes and Bacteroidetes. At the genus level, the predominant bacterial genera were: RB41, Sphingomonas, WD2101_soil_group_unclassified, Pseudomonas and Actinomyces. The relative abundance of unknown genera was very large, which deserves further research. At the phylum and genus levels, the species abundance levels under slight and moderate degradation were significantly higher than those under extreme degradation. Correlation network diagrams showed there were many nodes in both slightly deteriorated and moderately deteriorated soils, and the node proportions were large and mostly positively correlated. These results indicate the bacterial communities in rhizospheric soils under slight or moderate deterioration are relatively stable. The rhizospheric soil microbes of desert steppes can form a stable network structure, allowing them to adequately respond to environmental conditions. Conclusions The bacterial communities in the rhizospheric soils of herb plants differ between different degradation gradients. The species number, abundance and diversity of bacterial communities in rhizospheric soils are not directly correlated with degree of degradation. The abundance, species diversity and species abundance of bacterial communities in the rhizospheric soils of moderately degraded desert steppes are the highest and most stable. The soil bacterial diversity is lowest in severely degraded desert steppes.

This study aimed to clarify the effects of stumping on the fine root architecture of decaying Hippophae rhamnoides plantation in feldspathic sandstone areas, and to determine the optimal stump height that is contributive to the recovery and growth of H. rhamnoides. The fine root architecture, and the econometric properties of soil organic carbon (C), total nitrogen (N) and total phosphorus (P) in fine roots and rhizosphere roots as well as the underlying correlations were analyzed after different stump height treatments (0 cm, 10 cm, 15 cm, 20 cm, no stumping). The above treatments all significantly affected fine root architecture, which grew into fishtail branches in all treatments. Especially, at the stump height of 15 cm, the topological index (0.75), total branching rate (1.91), specific root length (69.69), and average diameter (0.62) of fine roots were all better than after other treatments. Stumping did not significantly affect C content of fine roots, P and C: N ratio of rhizosphere soils, but very significantly affected other nutrient contents and the stoichiometric ratios of both fine roots and rhizosphere soils. These results indicate the stump height of 15 cm better promote the growth of H. rhamnoides. Principal component analysis shows the N, P, C:N of fine roots, and the C, C:P of rhizosphere soils maximally affect the fine root architecture. Our findings are critical for vegetation recovery and soil erosion prevention and control in feldspathic sandstone areas.

The effects of different nano Fe2O3 dose on water movement, solute transport as well as metal adsorption are studied. The main results showed that: nano Fe2O3 inhibited the process of soil water infiltration and the infiltration rate decreased with the increase of nano Fe2O3 dose. Nano Fe2O3 can improve the water-holding capacity of soil, while under the same soil water suction, soil water contents and the inlet suction increased with the increase of nano Fe2O3 contents, but the shape parameter decreased. Nano Fe2O3 improved soil solute holding ability effectively; with the increase of nano Fe2O3 dose, initial penetration time and the dispersivity increased, but the breakthrough time prolonged.