Search

Gully erosion poses a significant global concern due to its role in land degradation and soil erosion, particularly pronounced in Northeast China's diverse agro-geomorphic regions. However, there is a lack of comprehensive studies on gully characteristics, development rates, and the topographic threshold of gully formation in these areas. To address this gap, we selected three different agro-geomorphic watersheds, named HL (Hailun), ML (Muling), and YKS (Yakeshi), with areas of 30.88 km2, 31.53 km2, and 21.98 km2, respectively. Utilizing high-resolution (2.1 m, 2 m) remote sensing imagery (ZY-3, GF-1), we analyzed morphological parameters (length, width, area, perimeter, etc.) and land use changes for all permanent gullies between 2013 and 2023. Approximately 30% of gullies were selected for detailed study of the upstream drainage area and gully head slopes to establish the topographic threshold for gully formation (S = a·A−b). In HL, ML, and YKS, average gully lengths were 526.22 m, 208.64 m, and 614.20 m, respectively, with corresponding widths of 13.28 m, 8.45 m, and 9.32 m. The gully number densities in the three areas were 3.14, 25.18, and 0.82/km2, respectively, with a gully density of 1.65, 5.25, and 0.50 km km−2, and 3%, 5%, and 1% of the land has disappeared due to gully erosion, respectively. YKS exhibited the highest gully head retreat rate at 17.50 m yr−1, significantly surpassing HL (12.24 m yr−1) and ML (7.11 m yr−1). Areal erosion rates were highest in HL (277.79 m2 yr−1) and lowest in YKS (105.22 m2 yr−1), with ML intermediate at 243.36 m2 yr−1. However, there was no significant difference in gully expansion rate (0.37–0.42 m yr−1) among the three areas (p > 0.05). Differences in gully development dynamics among the three regions were influenced by land use, slope, and topographic factors. The topographic threshold (S = a·A−b) for gully formation varied: HL emphasized drainage area (a = 0.052, b = 0.52), YKS highlighted soil resistance (a = 0.12, b = 0.36), and the parameters a and b of ML fell within the range between these of HL and YKS (a = 0.044, b = 0.27). This study has enriched the scope and database of global gully erosion research, providing a scientific basis for gully erosion prevention and control planning in Northeast China. [ABSTRACT FROM AUTHOR]

Clanis bilineata Walker (Lepidoptera: Sphingidae), a burgeoning edible insect, is experiencing rising demand in China and other regions. Despite this interest, larval production is currently constrained by the limitations of artificial production technologies, particularly the selection of optimal host plants. This study rigorously evaluated the performance of C. bilineatha larvae on four main host plants: round-leaf soybean, pointed-leaf soybean, black locust, and kudzu. Preference tests demonstrated that the larvae were most attracted to black locust (34.76 ± 4.65%), with subsequent preferences for kudzu (25.00 ± 6.12%), round-leaf soybean (23.17 ± 2.79%), and pointed-leaf soybean (14.02 ± 4.74%). No significant preference differences were noted between round-leaf soybean and either black locust or kudzu. In feeding assays, the larvae exhibited a marked preference for round-leaf soybean (37.36 ± 0.81 g, total feeding amount for larvae), followed by kudzu (37.26 ± 0.82 g), pointed-leaf soybean (35.38 ± 1.31 g), and black locust (28.53 ± 0.81 g). When the larvae were fed on round-leaf soybean, they exhibited significantly higher survival rate (39.33 ± 0.90%), body weight (9.75 ± 0.07 g), total biomass (383.43 ± 7.35 g), pupation rate (87.78 ± 1.73%), and egg production (189.80 ± 1.06 eggs/female) compared to other hosts. These findings uncovered that round-leaf soybean significantly enhances larval performance, suggesting its potential for improving C. bilineata larval production and sustainability in cultivation systems. [ABSTRACT FROM AUTHOR]

Afidopyropen, a novel biorational insecticide, was registered in China in 2023 for the control of tea leafhoppers in tea plantation. In this study, an analytical method was developed for the determination of afidopyropen and its metabolite M440I007 in tea tissues by a modified QuEChERS method combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Roots, stems and leaves of tea plants were extracted by water and acetonitrile, and purified with primary secondary amine (PSA), hydroxylated multi-walled carbon nanotubes (MWCNT-OH) and graphitized carbon black (GCB). The target compounds were determined by UPLC-MS/MS in multiple reaction monitoring (MRM) mode, and quantified by external standard method with matrix-matched standard curve. Both targets display excellent linearity (R²>0.999 5) in the range of 0.002-5.000 mg·L-1. The recoveries of both compounds at the spiked levels of 0.005-2.000 mg·kg-1 ranged from 78.3% to 106.0% with the relative standard deviations (RSD) ≤ 12.85%. The limits of quantification (LOQs) and detection (LODs) of the method were 0.005 mg·kg-1 and 0.002 mg·kg-1, respectively. The developed method was applied to detect afidopyrofen and M440I007 in tea seedling tissues cultured in soil treated with afidopyropen in a pot experiment for 7 days. The results show that the distribution of afidopyropen in the tissues was roots (0.102 mg·kg-1) > stems (0.078 mg·kg-1) > leaves (0.007 mg·kg-1). The translocation factors, TFroot-stem and TFstem-leaf, were both less than 1, and the residue levels of the metabolite M440I007 were below the LOQ. The method established in this study is low-cost, accurate and sensitive, which can serve as a technical basis for further research on the uptake and transport behaviors of afidopyropen and M440I007 in tea plants. [ABSTRACT FROM AUTHOR]

Soil structure and its change are good indicators for soil quality and environmental stability, and land-use change is known to be an important factor that affects soil structure. We investigated the seasonal and temporal variability in the soil structure and evaluated soil erodibility under different land-use and land-management practices in the Mollisols region of Northeast China. We considered five land-use and land-management modes in the sloping land (5°), i.e., bare land (BL), natural vegetation restoration (NVR), artificial forest (AF), no-tillage (NT), and conventional tillage (CT). The bulk density (BD), aggregate size distribution, and aggregate stability (AS) were determined for each mode. Meanwhile, we estimated the runoff depth (RD) and sediment yield (SY) to assess the soil erodibility. The lowest BD in CT occurred in May, but no seasonal change in BD was observed in other treatments. After 15 years, the NVR and CT had increased BD values, while the BD of NT declined significantly over time. The >2 mm size fractions and the AS of NVR, NT, and CT were the largest in August, while those of BL decreased during the growing season. Furthermore, the >2 mm size fractions and the AS of BL, NT, and CT decreased over the long-term study period, but NVR and AF exhibited no significant inter-annual changes in the AS. The BD and AS in NVR and AF were greater than those in BL. After 15 years, the BD of NT and CT were not significantly different, but NT had a greater AS. The AS was greater in the subsurface soil than in the topsoil of NT and CT. Moreover, the NVR and NT had significantly reduced RD and SY compared with BL and CT. These results provide a scientific basis for choosing sustainable agriculture and land development modes to control soil erosion in Northeast China. [ABSTRACT FROM AUTHOR]

[Display omitted] • Linear, areal, and volumetric gully erosion rates were quantified during 2013–2021. • Ridge orientation, road and shelterbelt had different effects on gully erosion rate. • Horizontal ridge tillage can promote headcut retreat under heavy precipitation. • Tillage downslope on both sides of gully is recommended to limit gully expansion. • The coupling of topography and human activity mainly contributes to gully erosion. Gully erosion poses greater threat to ecological and food security globally. The gully development rate and the contributions of primary influencing factors have not been thoroughly understood, primarily due to the complicated environmental conditions characterized by climate, soil, topography, and human activities. Therefore, this study was conducted to explore the gully development and contributions of its driving factors from 2013 to 2021 based on historical Google Earth images and field investigation in a typical rolling hilly watershed of northeast China. The climatic factors reflected by precipitation, topographical factors related to gully, and anthropological factors reflected by tillage ridge orientation and linear anthropological factors (LAF) including roads and shelterbelts were obtained. The tillage effect index (TEI), LAF effect index (LEI) and the distance from gully to LAF (D L) were calculated to analyze the influence of anthropological factors on gully development. The results showed that the linear, areal and volumetric gully development rates (R L , R A and R V) showed great variabilities in different periods with the average of 5.69 m year−1, 137.37 m2 year−1 and 428.54 m3 year−1, respectively. The accumulated R L , R A and R V increased exponentially or linearly with accumulated precipitation amount (P), erosive rainfall duration (RD), erosive rainfall (ER), maximum 30-min rainfall intensity (I30) and rainfall erosivity (RE) increased (P < 0.001). The slope of the gully head (HS) was identified as the primary topographic factor influencing R L. Both R A and R V showed positive power relationships with the drainage area of the gully (CA) and the upstream gully head (HA). The human activity reflected by tillage ridge orientation, unpaved road and shelterbelts had different effects on R L and R A. The increased orientation angle between gully and tillage ridge (ROA) mitigated headcut retreat for normal precipitation year but it would aggravate headcut retreat in the periods of continuous heavy rainfall. Gully bank with the ROA of 30−90° was more prone to areal development. The TEI, LEI and D L had significantly positive linear, power or exponential relations with gully development rates. The PLSR and VPA analysis indicated that topography, the interaction between topography and human activity, and the coupled effects of precipitation, topography and human activity were the main contributor of R L , R A and R V , respectively, and accounted for 34 %, 50 %, and 40 % of total variability of R L , R A and R A , respectively. This study can provide guidance for the control of gully erosion and the optimization of land use structure in the gully catchment. [ABSTRACT FROM AUTHOR]

In recent decades, the global climate has changed significantly. The climate in Northwest China became warm-wet, especially in the Tianshan Mountains. In order to explore the response of tree growth to recent climate change, the two dominant trees species, Picea schrenkiana Fisch. et Mey. and Larix sibirica Ledeb., were studied with the dendrochronological method in the western Tianshan Mountains (WT) and the eastern Tianshan Mountains (ET). Our results showed that: (1) The tree growth of four sample sites in the WT significantly increased in recent decades, while the trees in the three sample sites in the ET significantly decreased. (2) In the WT, except for the Manas site, the tree-ring chronologies of the other three sites were significantly positively correlated with the mean annual minimum temperature. Tree-ring chronologies in the WT, except for Bangfanggou site, were significantly positively correlated with annual precipitation. In the ET, only the tree chronology of L. sibirica in the Balikun site was significantly negatively correlated with the annual temperatures, including the mean minimum, mean and mean maximum temperature. (3) The proportion of trees with a significant upward growth trend at each site decreased from west to east, and the proportion of trees with a significant downward growth trend at each site increased from west to east along the whole Tianshan Mountains. (4) The correlation of tree-ring chronologies with the annual temperature and annual precipitation was not stable during the study period. Warm-humidification promoted the growth of trees in the WT but inhibited tree growth in the ET, which may be exacerbated drought stress in the ET where the increase in precipitation was not enough to offset the increased evapotranspiration potential caused by warming. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pymetrozine is a widely used pesticide. It is challenging to analyze and difficult to manage due to the large gap in its global maximum residue limits (MRLs) in tea. The development of a high‐efficiency detection method for the evaluation of the transfer of residual pymetrozine from tea plantations to tea cups is therefore of prime significance. RESULTS: An analytical method for the determination of pymetrozine residues in tea was established based on Cleanert PCX solid‐phase extraction. The average recoveries were 72.2–93.7%, with relative standard deviations (RSDs) of less than 12%. The limits of quantification (LOQs) were 0.005 mg·kg−1 in fresh tea leaves and dry tea, and 0.00025 mg·L−1 in tea brew. Pymetrozine degraded rapidly in tea plants with a half‐life (t1/2) of 1.9 days in open tea plantations, and decreased by 9.4–23.7% in the green tea‐processing procedure, which was concentration dependent. The residual pymetrozine levels in green tea collected at 6 and 21 days were below the MRLs in China and EU at a dosage of 30 g a.i. ha−1, respectively. The leaching rates of pymetrozine from dry tea to tea brew were 58.7–96.3%. Hazard quotient (HQ) values of pymetrozine were significantly <100% when tea shoots were plucked in 6 days, which indicated a negligible risk to humans. CONCLUSION: This work allows the determination of residual pymetrozine in tea and illustrates a low intake risk with the use of pymetrozine in tea plantations. It could serve as reference for further regulation consideration for maximum residue limits (MRLs). © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

• Factors affecting spatial heterogeneity of WSA, MWD and K factor are clarified. • Soil property, terrain and land use contribute to 47%, 41% and 9% of total variation. • Influencing network and paths of factors driving WSA, MWD and K are confirmed. • Terrain signally affects WSA, MWD and K by altering soil nature and land use pattern. Soil aggregate stability and erodibility reflect soil resistance to erosion. Although the factors influencing soil aggregate stability and erodibility have been extensively studied, the driving effects of these factors and their interactions remain limited. 184 sampling sites were selected in topsoil (0–20 cm) of a small watershed (1.42 km2) in a Mollisol watershed to measure soil bulk density (BD), soil porosity (SP), soil moisture content (MC), soil organic carbon (SOC), total nitrogen (TN), >0.25 mm water stable aggregates content (WSA > 0.25), mean weight diameter (MWD) and K factor. Pearson correlation analysis, semi-variance function, redundancy analysis (RDA), and structural equation model (SEM) were used to quantify the impact of environmental variables (individual and interaction) on the spatial variations of WSA > 0.25 , MWD, and K factor. The findings indicated that higher values of WSA > 0.25 and MWD are observed in the central and western watershed, while the K values tend to be lower in areas with high WSA > 0.25 and MWD values within the watershed. The Exponential model optimally described WSA > 0.25 , MWD, and K factor with C 0 /(C + C 0) indicating moderate spatial dependence for MWD (39.79 %) and K factor (42.86 %), while strong spatial autocorrelation for WSA > 0.25 (7.23 %). Soil properties (moisture content, silt content, and bulk density), topography (elevation, SPI, and slope), and land use contributed 46.6 %, 41.4 %, and 9.1 % of the spatial variation in WSA > 0.25 , MWD, and K factor, respectively. SEM revealed that silt content, SOC, and water condition played a fundamental role in controlling the spatial variability of WSA > 0.25 , MWD, and K factor. Topography exerted both direct or indirect effects by coupling land use or soil properties spatially. Land use had direct or indirect effects on WSA > 0.25 and K factor through regulating MC, but it primarily influences MWD indirectly through impacting MC. These results could clarify the roles and influencing paths of factors controlling the spatial heterogeneity of WSA > 0.25 , MWD, and K factor, contributing to optimizing land management strategies. [ABSTRACT FROM AUTHOR]

Land use/cover plays a crucial role in gully head retreat (GHR). However, little is known about how land use/cover influences GHR rates. An in situ simulation experiment of rainfall and upstream inflow was conducted in a gullied loess region to investigate hydraulic erosion, mass movements, and linear GHR processes under three types of land use/cover (bare land, grassland, and shrub‐grass land). The results showed that the average linear GHR rates on grassland and shrub‐grass land were 87–89% and 72–81% lower than that on bare land (0.99–2.06 cm min−1), respectively. Gully heads retreat by hydraulic and gravitational erosion. In the case of hydraulic erosion, upstream runoff incision is dominant on bare land, while undercutting by on‐wall and jet flow dominates on grassland and shrub‐grass land. In the case of mass movement, collapse dominates with a frequency of 62–100%, of which gully sidewall collapse is most common, especially on bare land and it acts to widen the gully. Gully headwall collapse dominates on grassland and shrub‐grass land to cause retreat of the gully head. Overall, on bare land, upstream runoff incision dominates GHR. However, on grassland/shrub‐grass land GHR is mainly driven by the undercutting of on‐wall and jet flow and subsequent gully headwall collapses. As a consequence, the GHR length on bare land exponentially increases over time, while on grassland or shrub‐grass land, it discretely increases as an analogous step function. Moreover, the average linear GHR rate on grassland was considerably lower than that on shrub‐grass land, implying that an optimized vegetation restoration pattern enhances GHR control. [ABSTRACT FROM AUTHOR]

Vegetation plays an important role in gully headcut erosion in China's Loess Plateau, but little is known about the effects of root density on gully headcut erosion. This study attempted to investigate the effects of grass root density on gully headcut erosion and morphological development of the gully head using plots with different grass root densities (with bare land as the control). The experiment was performed on plots with different grass root densities, and the rainfall intensity and inflow discharge increased throughout the experiment. The results showed that headcut migration in bare land was mainly activated by upstream flow incision, headwall erosion, and plunge pool erosion, whereas headcut migration in grassland was driven by soil‐root matrix collapse at the headcut, headwall erosion, and plunge pool erosion. The soil loss rate (SLR), gully headcut retreat distance (GRD), gully area (GA), and upstream soil loss volume (SLVU) in grassland plots with different root densities were 45.64–68.45%, 66.97–85.38%, 69.26–78.18%, and 67.89–87.02% less than those in the bare land plots, respectively. However, as root density increased, the gully depth in the grassland plots increased from 19% to 59%, and the proportion of gully head soil loss volume (SLVGH) to the total soil loss volume increased from 63.37% to 88.37%. The SLR, GRD, GA, and SLVGH showed decreasing trends as the root density increased, as described by a Hill curve. Moreover, roots with diameters of 0–0.5 mm had greater effects on soil loss and morphological evolution than roots with larger diameters. Our results provide a reference for the reasonable selection of grass root density for controlling gully headcut erosion in China's Loess Plateau. [ABSTRACT FROM AUTHOR]

• A field investigation of gully erosion was conducted in a 121.50 km2 area. • A optimized gully volume estimation model was built by threshold iteration method. • Topographic threshold model of gully initiation was built by the quantile regression. • 49% of the study area was in a high sensitivity of gully erosion. Gully erosion is an essential source of soil loss in the world, severely causing land degradation and threatening food security. It is essential to explore the gully morphological characteristics and identify the topographic threshold for gully initiation for the control and prevention of gully erosion. However, limited information about the gully morphological characteristics, volume (V) estimation model and topographic threshold model of gully initiation is available in the rolling hilly Mollisols area of northeast China where gully erosion is prevalent. Herein, a detailed field investigation was carried out in a region of 121.5 km2 to obtain morphological parameters of each gully and the slope (S) and contributing area (A) of each gully head. The results showed that 383 permanent gullies were identified, with the mean length, top width and depth of 511.12 m, 7.84 m and 2.34 m, respectively. Most values of length, top width and depth were in the range of 50–250 m, 1.0–5.0 m and 0.5–3.0 m, respectively. The gully density is 1.61 km km−2 with 1.6% of land disappearing. These gullies are longer, narrower and shallower in this study than other regions of the world. Gully volume showed the optimal relationship with gully surface area (A g). An optimized power piece-wise models of V-A g , classified by gully top width (TW) using threshold iteration method provided a better predicted result. Topographic threshold model (S = 0.033A−0.171) of gully initiation was established by the quantile regression. This study highlights the severity of gully erosion in this major grain producing area of northeast China and proposed a new method for gully volume estimation, which could provide scientific reference for the design and plan of gully erosion control measures and the prevention of gully erosion. [ABSTRACT FROM AUTHOR]

Introduction. Although obesity has been reported worldwide as a risk factor for breast cancer, there are still some inconsistencies regarding the association between obesity and breast cancer. Body mass index (BMI) is used most to assess the extent of obesity; however, the association of other body size characteristics, such as waist and hip circumference, with susceptibility to breast cancer in Chinese Han women needs to be better assessed. Patients and Methods. Female Chinese Han patients (N = 2,800) were recruited from 21 hospitals in northern and eastern China from April 2012 to April 2013 for a case-control study.The significant differences of factors related to body size between the breast-cancer case and control groups were determined by Student's t test and chi-square tests. Results. Premenopausal women with breast cancer had higher BMI and larger waist and hip circumferences (p = 2 x 10-4, <1 x 10-6, and 2 x 10-5, respectively). However, these body-size factors were not associated with postmenopausal breast cancer (p = .45,0.32, and 0.12, respectively). BMI between 28 and 30 kg/m² or greater than 32 kg/m² was related to breast cancer incidence in the overall study population and in premenopausal women but not in the postmenopausal group. Conclusion. Obesity is significantly associated with breast cancer in Chinese Han premenopausal women but not in postmenopausal women. Thus, it is important to realize that weight control, as well as avoiding abdominal obesity, should be considered as one of the most effective methods of reducing breast cancer risk. [ABSTRACT FROM AUTHOR]

Rill erosion is one of the main forms of soil erosion of the hillslopes on the Loess Plateau of China. Few studies have evaluated the effects of land use on the distribution and morphology of rills under extreme rainstorms. A total of 50 rill survey sites were selected in a typical watershed of the Loess Plateau of China to investigate the rill distribution and morphology of three land uses (fallow land, FL; slope farmland, SF; and annual grassland, AG) under extreme rainstorm conditions (called "7·26" rainstorm). Seven parameters (rill width, rill depth, width-depth ratio, cross-section area, rill density, degree of rill dissection and rill erosion modulus) were used to characterize rill morphology, and the basic soil and vegetation properties (bulk density, particle size distribution, and vegetation coverage) and topographic factors (slope length, gradient, direction) were measured. It was found that rills developed on three land uses, and those with widths ranging from 5 to 20 cm accounted for >80%. Rills developed on FL were deeper than those on SF and AG. Almost all rills on FL had a depth of 5–20 cm (90.3%), while the depth of rills on SF and AG were mainly smaller than 15 cm (91.5% and 91.9%, respectively). In addition to width, rill depth and cross-section area of SF and AG were also significantly less than those of FL. SF and FL had a relatively high width-depth ratio and dissection degree. However, land use had no significant effect on rill density. Crop plantations (SF) and grass restoration (AG) significantly reduced rill erosion modulus (28.70% and 45.07% reduction, respectively). Land use, topography, soil, and vegetation factors significantly affected rill morphology (p = 0.001) based on redundancy analysis (RDA) and can explain 48.0% of the total variability of rill morphology, with slope length, vegetation coverage and slope gradient having the greatest influences. Most of the rill morphological parameters significantly decreased as the vegetation coverage increased but they significantly increased with increasing slope length and slope gradient. This study clearly illustrates the severe rill erosion caused by this rainstorm, and indirectly indicates that crop harvesting (FL) aggravates rill erosion and that revegetation (AG) can effectively contain rill erosion. Therefore, rehabilitation efforts should be focused on revegetation (grassland and/or woodland) on steep slopes to control soil erosion. • Rill development of three land uses was investigated under extreme rainfall. • Crop and grass can contain the development of rills >15 cm wide and 10–20 cm deep. • Cropland and grassland reduce rill erosion rate by 28.70% and 45.07%, respectively. • Land use, topography, soil and plant explain 48% of variability of rill morphology. [ABSTRACT FROM AUTHOR]

• A field investigation of gully erosion was conducted in a 393 km2 area. • Larger ridge orientation angle and sunny slope were conducive to gully development. • Gully volume can be well predicted by a power function of gully area. • Soil loss caused by gully erosion occupied by 65% in northeast China. Gully erosion, one of the most damaging forms of land degradation, destroys farmlands and threatens grain and ecological stability. Approximately 295,000 gullies have formed in the Mollisols region of northeast China (NEC), while the actual severity of gully erosion remains unclear. This study aims to clarify gully morphology, factors influencing gully morphology, and contribution of gully erosion to soil loss through a 393 km2 field investigation in a typical and representative Mollisols region of NEC. There were 1048 gullies observed, with an average length, top width, depth and width-depth ratio of 522.32 m, 15.05 m, 2.77 m and 7.16, respectively. Over 70% of gullies had a length, top width and depth of 100–500 m, 3–20 m and 0.5–3 m, respectively. The three types of gullies, classified based on where the gully head developed (GF, farmland; GR, unpaved road; GW, woodland), had significantly distinct morphologies, with GW being broader and deeper and GF being longer. Notably, 56.2% of gullies are GF, accounted for 74.84% of the total gully area and 67.04% of the total gully volume (V). V of GF, GR and GW could be well explained by a power function of gully area (A). Gully density (gully length per unit area, GD, km km−2) and ground lacerative degree (gully area per unit area, GLD, km km−2) increased with slope gradient, and first increased and then decreased with slope length. Gully development was more favorable of sunny slope and a larger angle between gully and ridge orientation. The annual eroded soil from the gully was 1.86 times of that from the hillslope across the region during 2013–2018, contributing 65% of region eroded soil. This clearly identifies the severity of gully erosion and substantiates gully erosion risks to valuable mollisols and therefore food security. An urgent need exists to implement gully erosion control practices in this area. [ABSTRACT FROM AUTHOR]

Mass movements are predominant geomorphic processes on steep hillslopes. However, the mechanisms governing the erosion and entrainment of mass movements remain poorly understood. In this study, experiments on natural loess slopes were conducted to induce a series of mass movements under simulated rainfalls in the Liudaogou Catchment on the Loess Plateau of China. A novel topography meter was used to observe random mass movements. A total of 499 mass movements in 42 rainfall events and an average of 11 mass movements for each rainfall event were observed. Three mass movement types were detected: landslides (67%) > mudflows (21%) > avalanches (12%). The volume of landslides dramatically increased through the entrainment of a wet gully bed material, and the volume of landslide mass was magnified by 29% on average through material entrainment. Based on the observed data, the probability of mass movement occurrences decreased with the increasing mass movement volume in a power-law relationship. The critical rainfall amount for mass movement failure was approximately 25.6 mm at a rainfall intensity of 50 mm h−1. These results can serve as guides to mitigate geological hazards and assess erosion processes on steep loess slopes of the Loess Plateau. • Process of erosion and entrainment of mass movement was monitored on natural slope. • Material entrainment in steep gully can increase the volume of mass movements. • Probability of mass movement decreases with failure volume in power-law relationship. • The results are referred as a guide to assess erosion process on hillslope. [ABSTRACT FROM AUTHOR]

Background: The increasing prevalence of physical inactivity and prolonged Recreational Screen Time (RST) among children and adolescents is emerging as a significant public health concern. This study investigates the current status of Physical Activity (PA) and RST among Chinese children and adolescents from 2017 to 2019. It also examines variations in PA and RST across different school levels, genders, urban-rural areas, regions, and seasons., Methods: A national cross-sectional survey, conducted in China from 2017 to 2019, included 53,101 children and adolescents from grades 4 to 12 (aged 10 to 18 years old). Data on PA and RST were collected via self-administered questionnaires. The study employed descriptive statistics, calculated weighted prevalence rates, and conducted differential analysis across diverse demographic groups., Results: Between 2017 and 2019 in China, merely 28.73% of children and adolescents adhered to World Health Organization's PA guidelines, while 76.09% met China's RST guidelines. Notably, females, higher-grade students, rural residents, and children and adolescents from southern regions exhibited significantly lower levels of PA compared to their male, lower-grade, urban, and northern counterparts. Concurrently, RST was significantly higher among males, lower-grade students, rural residents, and those from northern regions. Seasonal variations were also observed, with lower PA and higher RST in autumn and winter as compared to spring., Conclusion: The study reveals a concerning low level of PA among Chinese children and adolescents, with marked disparities in PA and RST across different groups. This underscores the need for targeted health promotion strategies to enhance PA and mitigate RST among various child and adolescent populations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Guo, Zhu and Wang.)

Revegetation is among the most efficient methods to improve gully headcut erosion. However, the influencing mechanism of revegetation on the soil properties of the gully head (GHSP) is still unclear. Thus, this study hypothesized that the variations in the GHSP were influenced by vegetation diversity during nature revegetation, and the influence pathways were mainly root traits, aboveground dry biomass (ADB), and vegetation coverage (VC). We studied six grassland communities of the gully head with different natural revegetation ages. The findings showed that the GHSP were improved during 22-year revegetation. The interaction effect of vegetation diversity, roots, aboveground dry biomass, and vegetation coverage on the GHSP was 43 %. In addition, vegetation diversity significantly explained >70.3 % of the changes in the root traits, ADB, and VC of the gully head (P < 0.05). Therefore, we combined vegetation diversity, roots, ADB, and VC to establish the path model to explain the GHSP changes, and the goodness of fit of the model was 82.3 %. The results showed that the model explained 96.1 % of the variation in the GHSP, and the vegetation diversity of the gully head affected the GHSP through roots, ADB, and VC. Therefore, during nature revegetation, vegetation diversity dominates the improvement of the GHSP, which has important significance for designing an optimal vegetation restoration strategy to control gully erosion., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Vegetation restoration is the most important factor to restrain soil and water loss in the Chinese Loess Plateau, and its effect is long-term. Among them, the coupling and coordination relationship between vegetation and soil is the key to the smooth implementation of ecological restoration and the project of returning farmland to forest and grassland. However, people have neglected whether the choice of vegetation restoration method is suitable for the development of ecological environment in this region, and whether vegetation and soil coexist harmoniously. In this paper, the typical watersheds with similar terrain environment but different vegetation restoration methods were selected as the research objects, which were Dongzhuanggou (natural restoration, NR) and Yangjiagou (artificial restoration, AR). Through vegetation investigation and soil physical property experiment, the comprehensive evaluation function was used to quantify the impact of restoration methods on vegetation characteristics and soil properties, and the vegetation-soil coupling model was used to explore the coordinated development of vegetation and soil under different restoration methods. The results showed that there were significant differences between the two restoration methods in terms of vegetation characteristics (P < 0.05). The vegetation diversity indices of NR were 1.59-4.81 times that of AR. For root characteristic indices, NR was 1.05-2.25 times that of AR. For soil physical properties, there was no significant difference between the two restoration methods (P > 0.05). The comprehensive evaluation function of vegetation (VCE) and soil (SCE) under NR were 0.74 and 0.42, respectively, while those under AR were 0.55 and 0.63, respectively. The comprehensive function showed that the vegetation population performance under NR was slightly better than that under AR, while the soil restoration effect was opposite. Under the two restoration methods, the vegetation-soil coupling relationship was barely coordinated (NR: 0.53; AR: 0.54), and both were the intermediate coordinated development mode. The vegetation diversity, tending level and soil management level should be improved simultaneously during the process of vegetation restoration on the Chinese Loess Plateau., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Severe rill erosion on dump slopes poses a great threat to the ecological environment in mining areas. Vegetation restoration is an effective measure for controlling soil erosion on dump slopes. However, few studies have identified the long-term influence of vegetation restoration on rill development on dump slopes. Therefore, we investigated the rill development characteristics of dump slopes with three typical restoration models (CK: natural restoration; ED: Elymus dahuricus; and AO: Artemisia ordosica) and three recovery time (1 y, 3 y and 5 y). The results showed that vegetation adequately controlled rill erosion on dump slopes. ED and AO could effectively control the development of rills with widths >15 cm and depths of 10-20 cm. ED vegetation restoration inhibited the development rill morphology and network better than AO. The rill erosion modulus of the ED slope and AO slope decreased by 76.29%-90.77% and 46.66%-61.49%, respectively, compared with that of natural restoration slopes with recovery time of 1 y, 3 y, and 5 y. ED controlled rill erosion better than AO, but this effect gradually weakened with recovery time. Vegetation coverage contributed 34.99% of the total variation in rill morphology and was the main factor affecting the development of rills on dump slopes. Furthermore, vegetation coverage had a more important role in controlling rill development than did the root system on dump slopes. This study provides valuable information for optimizing vegetation construction for soil loss control on dump slopes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Soil erodibility is an indispensable parameter for predicting soil erosion and evaluating the benefits of soil and water conservation. Slope situation can alter revegetation and its effects on soil properties and root traits, and thus may affect soil erodibility. However, whether slope situation will change the effect of revegetation on soil erodibility through improving soil properties and root traits has rarely been evaluated. Therefore, this study was conducted to detect the response of soil erodibility to slope situations (loess-tableland, hill-slope and gully-slope) in a typical watershed of the Loess Plateau. Five soil erodibility parameters (saturated soil hydraulic conductivity, SHC; mean weight diameter of aggregates, MWD; clay ratio, CR; soil disintegration rate, SDR; soil erodibility factor, K) and a comprehensive soil erodibility index (CSEI) are selected to clarify the study targets. The results revealed that soil properties, root traits, soil erodibility parameters and CSEI were affected by slope situation significantly. Soil and root can explain 79.7%, 79.1% and 69.8% of total variance in soil erodibility of loess-tableland, hill-slope and gully-slope, respectively. Slope situation influenced soil erodibility by changing the effects of revegetation on soil properties and root traits. Evidently, the slope situation greatly changed the relations between CSEI and soil and root parameters, whereafter a model considering slope situation (slope steepness), sand, organic matter content and root surface area density was reliable to estimate soil erodibility (CSEI). Our study suggested that the Armeniaca sibirica, the combination of Bothriochloa ischcemum and Robinia pseudoacacia and the combination of Armeniaca sibirica and Lespedeza bicolor can be used as the optimal selection for mitigating soil erodibility of loess-tableland, hill-slope and gully-slope, respectively. This study is of great significance in optimizing the spatial layout of soil and water conservation measures for different slope situations of the Loess Plateau., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objective: To investigate breast cancer risk factors in Chinese women residing in urban and rural areas of eastern China using a large-scale cross-sectional survey., Methods: In this multistage, stratified cluster sampling epidemiological survey, information on demographic characteristics, diet and lifestyle variables were gathered using a carefully designed questionnaire. Multivariate logistic regression analysis and subgroup analyses of the data were performed, including separate analyses of data from women residing in urban and rural areas., Results: A total of 122,058 women were included in the survey. Age, body mass index, number of miscarriages, family history of breast cancer and menopausal status were found to be risk factors for breast cancer, while the consumption of soya bean products was a protective factor. Among women residing in urban areas, high or moderate intake of soya bean products and red meat were protective factors. Among women residing in rural areas, obesity and a high intake of milk were identified as risk factors for breast cancer, while a moderate intake of soya bean products was a protective factor., Conclusions: This type of data is crucial for understanding the risk factors for breast cancer and could facilitate the development and targeting of effective intervention strategies, with the ultimate aim of breast cancer prevention., (© The Author(s) 2015.)