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Investigating the variations in leaf stoichiometry among plant common species at different altitudes, along with the factors that influence these variations and the adaptative strategies employed, is of significant importance for understanding biogeochemical cycles amidst global environmental changes. In this research, we measured soil organic carbon and nutrient concentrations, as well as leaf stoichiometry for plant common species at five altitudes (2400–3200 m with an interval of 200 m) within the Qilian Mountains of Northwest China. This study aims to enhance our understanding of how plant common species in mountainous regions exhibit adaptable responses to altitude variations and how potential environmental changes in the future may influence their leaf functions. Results showed that the leaf C:N:P stoichiometry of plant common species varied with increasing altitude. Across altitudes, mean annual temperature (MAT), soil total phosphorus, mean annual precipitation (MAP), soil water content, and soil nitrate nitrogen were the main factors influencing leaf element concentrations of plant common species. However, leaf stoichiometric ratios were mainly determined by MAT, MAP, and soil total nitrogen. The effects of MAT and MAP on both leaf element concentrations and leaf stoichiometric ratios of plant common species were found to be significant. Plant growth in the study area was mainly limited by P. The results not only highlight the adaptive strategies employed by plants, but also contribute to understanding of leaf stoichiometry, and establishing connections between individual plant species and broader plant community composed of these common species. [ABSTRACT FROM AUTHOR]

Arid and semiarid wetlands, the core geographical unit of desert oases, significantly benefit and improve the ecological environment. In this study, we systematically compared the spatiotemporal dynamics and driving forces of natural and constructed wetlands in arid and semiarid regions of northern China from 1995 to 2019. For these comparisons, we utilized a land-use transition matrix, partial least-squares–structural equation model (PLS-SEM), and geographically weighted regression (GWR) model. The results showed that (1) the area of wetlands as a whole showed an upward trend, with natural and constructed wetlands increasing by 4.16% and 11.86%, respectively. The increases mainly resulted from conversions of grassland and other lands (shrub, sparse vegetation, and bare land). (2) The direct dominant factors that drove natural wetland changes were soil and terrain, while those that drove constructed wetlands were human disturbances. Human disturbance, by affecting soil, had a higher significant indirect effect on natural wetlands. Heat, by affecting moisture, had the greatest indirect effect on constructed wetlands. (3) The sensitivity of natural and constructed wetlands to the responses of different drivers showed significant spatial heterogeneity. This study explores the interaction and driving mechanisms of human and natural attributes on natural and constructed wetlands and provides a scientific foundation for the restoration and sustainable development of wetlands in arid and semiarid areas. [ABSTRACT FROM AUTHOR]

Chromium is one of the eight most popular inorganic soil pollutants in China, and its bioavailability is determined by the chemical states. Amendments, which are able to change the chemical forms of chromium and decrease its bioavailability, have received considerable attention in recent years. In this work, the formation of Cr-based layered double hydroxides (LDHs) and the immobilization of Cr in solution and soil were systemically investigated. The formation of Cr-based LDHs is strongly depended on the layer charges, aging temperatures and reaction time, as identified by X-ray diffraction (XRD), transmission electron microscope (TEM) and X-ray absorption fine structure (XAFS) spectrum. According to the pot experiment results, the concentration of Cr in the overground part of Brassica Chinensis L. was significantly decreased to 1.50–2.03 µg kg− 1 in the present of amendments. In total, the finding of LDHs formation on amendments and the thermodynamic stability of LDHs provides a new insight into the remediation of Cr-polluted soils. [ABSTRACT FROM AUTHOR]

Economic development and trade activities are some of the main driving forces leading to land use and land cover changes (LUCC) with impacts on ecosystem services (ESs) functions. As the origin of the Belt and Road Initiative (BRI) initiated by China, Central Asia nations (CANs) provide a prism to examine the impact of LUCC and ESs changes brought by the BRI. The impacts of LUCC and ecological influences were evaluated. The land use transfer matrix and dynamic index, the Vector Autoregressive (VAR) model, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST), the Carnegie Ames–Stanford Approach (CASA) model, and the Revised Wind Erosion Equation (RWEQ) model were used to evaluate the impact of export trade from the CANs to China (ETCC) on LUCC and ESs in the CANs before and after the BRI. Results showed that before and after BRI (2001–2020), agricultural land and construction land increased by 59,120 km2 and 7617 km2, respectively, while ecological land decreased by 66,737 km2. The annual growth rate of agricultural land and the annual reduction rate of ecological land after the BRI were higher than that before the BRI, while the annual growth rate of construction slowed down. Among the ecological land, the forestland increased by 5828 km2 continuously, while the grassland increased by 12,719 km2 and then decreased of 13,132 km2. The trends for LUCC spatial variation were similar. The development of ETCC positively affected the changes in agricultural and construction land in the CANs and negatively affected the changes in ecological land. The average contribution rates of the ETCC to changes in agriculture, construction, and ecological lands after the BRI were higher than those before the BRI. They increased by 5.01%, 3.33% and 5.01%, respectively. The ESs after the BRI improved compared with those before the BRI, indicating that, during short-term implementation of the BRI, ETCC growth also ensures the ecological protection of CANs. This study provides a reference for dealing with trade, land management and environmental protection relations between member countries of international economic alliances worldwide. [ABSTRACT FROM AUTHOR]

Efforts to enhance food, fibre, and forage yields and achieve global food security have included the conversion of natural grasslands to cultivated grasslands. The quantitative effects of a global shift in grassland management on soil properties and microbial communities critical to ecosystem function have remained largely unexplored, particularly on China's Qinghai–Tibetan Plateau. Accordingly, the distinct and contrasting effects of annual Avena grasslands (AAG) versus perennial Elymus nutans Griseb. cultivated grasslands (PEG) on the region's soil properties and microbiome were investigated in an effort to examine their contribution to maintaining soil carbon and nutrients. Across three sites per grassland type, soil moisture content (45.55%), soil organic carbon (48.97 g kg−1), soil total nitrogen (5.13 g kg−1), and soil ammonium nitrogen (298.32 mg kg−1) were 19%–32% greater at PEG sites than AAG sites, whereas soil pH (7.81), soil total phosphorus (0.44 g kg−1), and soil available phosphorus (0.81 mg kg−1) were 2%–31% lower. The AAG and PEG site soils had different bacterial and fungal β‐diversities but similar α‐diversities. The relative combined abundance of Gemmatimonadetes and Chytridiomycota, and that of Rozellomycota individually, were, respectively, higher and lower in AAG versus PEG site soils. This suggests that, on the Qinghai–Tibetan Plateau, contrasting grassland cultivation practices affect soil properties and microbes differently. Given the strong interaction between a soil and its microbiome, changes in a soil's microbial community structure can be expected to substantially alter soil function. This will have important ecological service implications, particularly in terms of carbon storage and water conservation in this ecologically fragile region. [ABSTRACT FROM AUTHOR]

With the increase of mining depth, the occurrence mechanism of coal and gas outburst becomes more complex, and stress‐dominated outburst disaster has become one of the major safety problems in deep coal mines. Therefore, stress relief of coal seam has become an urgent technical demand for outburst prevention method in deep mines. In this study, based on zonal disintegration characteristics of deep surrounding rock, a regional strip outburst prevention method, called strip stress relief combined with gas extraction through stress‐relief floor roadway, was proposed, and relevant in‐site investigations were carried out in the Qujiang coal mine in China. Our results show that the zonal disintegration phenomenon occurs in the high‐stress surrounding rock at great depths, and induces the stress‐relief effect on the upper coal seam, in which the permeability and extraction radius of boreholes are increased greatly. The results of deformation and failure of surrounding rock of floor roadway show that from the surface to deep regions, fractured and nonfractured zones were alternatively distributed in the surrounding rock of deep floor roadways, the damage degree of surrounding rock was gradually weakened, and the width of fractured area was gradually reduced. The displacement of surrounding rock also presented the characteristics of alternative distribution of wave peak and trough. Moreover, the deformation and failure of surrounding rock presented a time‐dependent rheological behavior. In the stress‐relief zone, the coal seam permeability was enhanced significantly, with the maximum value being 43 times larger than that of the original coal seam. The effective gas extraction radius of the borehole was improved by 15%‐45%. During the driving period of coal roadways, the outburst risk prediction indexes K1 and S of the working face were lower than the critical value, and the driving speed of the coal roadway improved from 40 m per month to 100 m per month. This indicates that the proposed strip regional outburst prevention method can simultaneously reduce the ground stress and the gas content, and can effectively eliminate the outburst risk of coal roadway in deep mines. [ABSTRACT FROM AUTHOR]

Highlights • Afforestation is an important land use option decision for arid and semi-arid regions. • The effect of stand type and stand age on soil carbon storage (SC) was investigated. • The SC for the apricot stand with 40 yrs and 16 yrs was 88.36 Mg ha−1, and 56.16 Mg ha−1, respectively. • The SC for the poplar stand with 40 yrs was 79.07 Mg ha−1. • For afforestations in arid and semi-arid regions, a tradeoff between SC and soil water is required. Abstract Afforestation implemented on available lands that have a poor fertility with a low primary productivity is considered to be a significant land use change issue globally, especially in the current phase of increasing atmospheric CO 2 concentrations. However, different stand types and stand ages, where afforestation is initiated, may have a different effect on soil carbon storage. Two stand types, including the apricot and poplar stand, both with 40 years, and two stand ages, including the apricot stand with 40 years and apricot stand with 16 years were sampled on the Loess Plateau, to explore the differences in soil carbon storage between both of them, respectively. The results showed that the total soil carbon storage up to the 1.0 m soil depth for the poplar stand was 79.07 Mg ha−1, and for the apricot stand with 40 years was 88.36 Mg ha−1, while for the apricot stand with 16 years, it was 56.16 Mg ha−1. About 50% the soil carbon was stored in the 0-0.4 m soil layer for all these forested lands. This ascertains that the soil carbon was very sensitive to climate change and anthropogenic disturbances. Based on these results, if we are interested in combating global warming issue, the apricot trees can be a preferred option for future plantations. However, these plants are likely to consume more water than any other vegetation types. Since water is a limited resource both in arid and semi-arid regions, a tradeoff between soil carbon and soil water should also be considered in future afforestation policy options. [ABSTRACT FROM AUTHOR]

In exploring the effects of afforestation policies on soil water dynamics, soil moisture content was measured in two different rainfall events (within a lengthy drought period and during a drought-free period), up to 1.0 m depth, both at non-afforested and afforested sites situated in China’s central region. The non-afforested sites included abandoned and cropped lands. These were compared to lands afforested with either poplar or apricot of different stand ages: 16- vs . 40-year for apricot, and 40-year primary planting vs. c. 30-year secondary planting for poplar. The results showed that at the 1.0 m soil depth profile, the average soil moisture content across all forested lands was consistently inferior to that of either arable or abandoned lands both in the absence of rain and after rainfall events. The arable and abandoned lands showed no difference in soil moisture content in the absence of rain (9.16% vs. 9.24%, respectively), whereas a significant difference did exist after rainfall events (18.31% vs. 16.99%). However, among all the investigated land types, primary and secondary poplar stands showed the highest soil moisture content levels both before (≈10.00%) and after rain (≈18.50%), whereas apricot stand soil moisture content levels were approximately 7.17%, and 15.86%, before and after rain, respectively. Stand age had a significant effect on soil moisture content, with a 16-year stand of apricot being 8.44%, but a 40-year stand being 5.89%. Given that in the present study, afforestation species and stand age together with rainfall events influenced soil moisture content, these factors should be considered in implementing afforestation, and in making accurate comparisons among land use types in arid and semiarid regions, where water is the key limiting resource. [ABSTRACT FROM AUTHOR]

Climate change and overgrazing are believed by policy makers to have been the drivers of grassland degradation in China over the past thirty years. However, recent work has suggested that policies that have led to privatization of use rights and household enclosures are more important drivers of degradation. An analysis of available evidence from scienti fic publications and national survey data relating to climate change, livestock numbers, and management policy was undertaken to evaluate the case for each of these possible drivers of degradation. The analysis suggests that, to date, policy measures imposed to avoid the 'tragedy of the commons' have been more important than either climate change or overgrazing as a driver of degradation. The resulting fragmentation of the pastoral landscape has caused localized grazing pressure and spatial and temporal mismatches between grassland production and livestock access to forage. Grazing rights negotiated and allocated at a multiple-household level would allow greater productivity, better rangeland condition, possible advantages of scale and pooling of herder resources, and better potential to adapt to future climate change. [ABSTRACT FROM AUTHOR]

Terraces, which are typical artificial landforms found around world, are of great importance for agricultural production and soil and water conservation. However, due to the lack of maintenance, terrace damages often occur and affect the local flow process, which will influence soil erosion. Automatic high-accuracy mapping of terrace damages is the basis of monitoring and related studies. Researchers have achieved artificial terrace damage mapping mainly via manual field investigation, but an automatic method is still lacking. In this study, given the success of high-resolution unmanned aerial vehicle (UAV) photogrammetry and object-based image analysis (OBIA) for image processing tasks, an integrated framework based on OBIA and UAV photogrammetry is proposed for terrace damage mapping. The Pujiawa terrace in the Loess Plateau of China was selected as the study area. Firstly, the segmentation process was optimised by considering the spectral features and the terrains and corresponding textures obtained from high-resolution images and digital surface models. The feature selection was implemented via correlation analysis, and the optimised segmentation parameter was achieved using the estimation of scale parameter algorithm. Then, a supervised k-nearest neighbourhood classifier was used to identify the terrace damages in the segmented objects, and additional geometric features at the object level were considered for classification. The comparison with the ground truth, as delineated by the image and field survey, showed that proposed classification can be adequately performed. The F-measures of extraction on three terrace damages were 92.07% (terrace sinkhole), 81.95% (ridge sinkhole), and 85.17% (collapse), and the Kappa coefficient was 85.34%. Finally, the potential application and spatial distribution of the terrace damages in this study were determined. We believe that this work can provide a credible framework for mapping terrace damages in the Loess Plateau of China. [ABSTRACT FROM AUTHOR]

Leaf stoichiometry of plants can respond to variation in environments such as elevation ranging from low to high and success in establishing itself in a given montane ecosystem. An evaluation of the leaf stoichiometry of Qinghai Spruce (Picea crassifolia Kom.) growing at different elevations (2400 m, 2600 m, 2800 m, 3000 m, and 3200 m) in eastern China's Qilian Mountains, showed that leaf carbon (LC) and leaf phosphorus (LP) were similar among elevations, with ranges of 502.76–518.02 g·kg−1, and 1.00–1.43 g·kg−1, respectively. Leaf nitrogen (LN) varied with changes of elevation, with a maxima of 12.82 g·kg−1 at 2600 m and a minima of 10.74 g·kg−1 at 2800 m. The LC:LN under 2400 m and 2600 m was lower than that under other elevations, while LC:LP and LN:LP were not different among these elevations. Except for LN and LC:LN, P. crassifolia's other leaf stoichiometries remained relatively stable across elevations, partly supporting the homeostasis hypothesis. Variations in leaf stoichiometry across elevations were mainly linked to mean annual precipitation, mean annual temperature, soil pH, and the soil organic C to soil total N ratio. P. crassifolia growth within the study area was more susceptible to P limitation. [ABSTRACT FROM AUTHOR]

• The R:S ratio and root morphology were affected by duration of grazing exclosure. • Both were mainly influenced by soil nitrate nitrogen. • The root diameter showed little change with an increase of duration. • The root density and root length density increased with an increase of duration. • The relationship between root biomass and root morphology changed with duration. Unsustainable human actions and climate change have threatened global grasslands and lead to biodiversity loss and compromised ecosystem functions. Widely considered to be an effective approach to restore degraded grasslands, grazing exclosure (GE) likely affects biomass allocation and root morphology in the long-term, although their impacts are yet to be documented. The objective of this study was to investigate the effects of grazing exclosure durations of 5, 22, and 39 years (GE 5 , GE 22 , GE 39 , respectively) on root:shoot biomass allocation (R:S ratio) and root morphology — including root average diameter (RAD), root density (RD), specific root length (SRL), specific root area (SRA), and root length density (RLD) — in an alpine grassland on the Qinghai-Tibetan Plateau. Seasonal grazing (SG) land served as a control. In the 0−0.30 m soil layer, the R:S ratios of the SG (1.27) and GE 5 sites (0.90) were significantly lower than that of the GE 39 site (2.14). However, there was no difference between the GE 22 (1.83) and GE 39 sites. The R:S ratio of the 0−0.15 m soil layer showed an increasing trend with duration of grazing exclosure and had a significantly greater value under GE 39 (1.89) than under GE 5 (0.76). However, the R:S ratios for the 0.15−0.30 m soil layer (0.14, 0.28 and 0.25 for GE 5 , GE 22 , and GE 39 , respectively) showed no significant changes with grazing exclosure duration. In the 0−0.30 m soil layer across sampled sites, RAD remained constant, RD and RLD exhibited an increasing trend, while SRA and SRL displayed a slightly decreasing trend with grazing exclosure duration. Below-ground biomass (BGB) was most strongly related to RLD across all sites; to RD and RLD at the GE 5 and GE 22 sites, and to RAD and RLD at the GE 39 site. Both R:S ratio and root morphology were mainly influenced by soil nitrate nitrogen. Although long-term grazing exclosure enhanced BGB and R:S ratio, soil nutrients declined with increasing exclosure duration. Therefore, to achieve improved ecosystem functions, grazing exclosure should be used with caution in this area or other similar regions around the world. [ABSTRACT FROM AUTHOR]

• Soil carbon storage in afforested lands and in abandoned lands was compared in arid and semi-arid area, China • Carbon storage to a 1.0 m soil depth under the abandoned lands (80.58 Mg ha-1) was significantly higher than under the afforested stands (71.82 Mg ha-1) • As the loss of arable lands to urbanization worsening food security, focus should be placed on the economic use of abandoned lands through consolidation As in the rest of the world, China assumed afforestation was an effective means of helping to mitigate the negative impacts of global warming, soil erosion and soil degradation, and returned large areas of farmland to woodland. At the same time, due to industrialization and urbanization, large tracts of arable land were abandoned, especially on the Loess Plateau. To explore which land use type has greater potential to absorb carbon dioxide from the atmosphere and thus provide suggestions for land use policy in this region, a comparison of soil organic carbon storage under abandoned and afforested lands was undertaken in the northwest part of the Loess Plateau (Huining County, Gansu province, China). The soil water content, pH, soil bulk density, soil organic carbon content and overall organic carbon storage of soils (0-1.0 m depth) were measured in each of 21 plots (10 m × 10 m) on the abandoned (apricot trees) lands, and 21 similar plots on the afforested lands. Soils under the two land use types showed no significant differences in gravimetric water content or pH up to 1.0 m in depth. The soil bulk density, organic carbon content and organic carbon storage under the abandoned lands (1.18 Mg m-3, 7.07 g kg-1, and 80.58 Mg ha-1, respectively) were all significantly higher than under the afforested lands (1.13 Mg m-3, 6.62 g kg-1, and 71.8 Mg ha-1, respectively). Although benefits such as strong soil carbon fixation and lower water consumption were greater in the abandoned lands, this does not imply that afforested lands should be converted into abandoned lands, as they can provide wind barriers, reduce soil erosion, and maintain high biodiversity. However, given the integration of urban and rural development policies, as well as worsening food security issues attributable to the loss of arable lands to urbanization, some focus should be placed on the use of abandoned lands through consolidation. [ABSTRACT FROM AUTHOR]

• Elevation and slope aspect affected leaf stoichiometry of Oxytropis ochrocephala. • Variation of leaf stoichiometry with elevation was mainly affected by MAT, SOC and SOC:STP. • Variation of leaf stoichiometry with slope aspect was mainly affected by ST and SWC. Slope aspect and elevation gradient, important topographic factors, affect plant growth and leaf carbon:nitrogen:phosphorus (C:N:P) stoichiometry by regulating local water and energy balances. The response of leaf stoichiometry to topographic factors reflects plant adaptation strategies to different habitats. Common in various grasslands across China, Oxytropis ochrocephala Bunge. is well known in pastoral areas for its toxicity. The effects of partial or full slope sunniness (south-facing) or shadiness (north-facing) and elevation (2400 m, 2600 m, 2800 m, 3000 m, or 3200 m) on the leaf C:N:P stoichiometry of O. ochrocephala was investigated in northwest China's Qilian Mountains. While leaf C:N:P stoichiometry of O. ochrocephala changed with elevation, there was no uniform pattern of change: the greatest leaf C and P concentrations ([C] leaf , and [P] leaf) were measured at an elevation of 2800 m (417.81 g kg−1 and 1.17 g kg−1, respectively); the lowest [C] leaf was 360.43 g kg−1 at 2400 m, and the lowest [P] leaf was 0.81 g kg−1 at 2600 m. The greatest leaf N concentration ([N] leaf) was 38.29 g kg−1 at 3200 m, and the lowest was 31.94 g kg−1 at 2600 m. Leaf C:N, C:P and N:P ratios were all relatively greater at 2600 m. Across the elevation gradient, O. ochrocephala leaf nutrient concentrations and their stoichiometries were mainly determined by mean annual temperature, soil organic carbon, and soil organic carbon to soil total phosphorus ratio. The [C] leaf , [N] leaf , and [P] leaf were significantly greater on north-facing slope aspects (393.86 g kg−1, 38.04 g kg−1, and 1.16 g kg−1, respectively) than on south-facing slope aspects (365.39 g kg−1, 32.98 g kg−1, and 0.92 g kg−1, respectively). Leaf C:N, C:P, and N:P ratios were significantly lower on north-facing slope aspects (10.43, 416.49, and 39.73, respectively) than on south-facing slope aspects (11.14, 512.57, and 45.98, respectively). Differences in leaf nutrient concentrations and their stoichiometries in O. ochrocephala leaves between slope aspects were mainly determined by soil temperature and soil moisture content. In terms of leaf N:P ratios across the elevation gradient and the two slope aspects, results indicated that the growth of O. ochrocephala in the study region was mainly restricted by P. [ABSTRACT FROM AUTHOR]

Leaf stoichiometry can enhance our understanding of leaf elements' (C, N and P) concentrations and their corresponding ratios in an ecosystem with seasonal environment changes. This study quantified the seasonal dynamics of leaf stoichiometry of P. australis from Yangguan wetland, Dunhuang, China as a case study example. The leaf C concentration (LC) of P. australis changed between seasons and was 392.26 (g·kg−1), 417.35 (g·kg−1) and 392.58 (g·kg−1) in spring, summer and autumn, respectively. Leaf N and P concentrations (LN and LP) were 23.49 (g·kg−1), and 17.54 (g·kg−1) and 5.86 (g·kg−1), and 1.00 (g·kg−1), 0.75 (g·kg−1) and 0.16 (g·kg−1), respectively, in the three seasons. The maximum (77.68) and the minimum values (17.00) of LC:LN were observed in the autumn and spring, respectively. Seasonal variations in LC:LP also showed a similar trend, with the greatest value of 3015.91 in autumn and the lowest value of 429.39 in spring. However, the highest (45.67) and the lowest values (24.18) of LN:LP were observed in autumn and summer, respectively, indicating that the growth of P. australis was mainly affected by P. Based on these results, it can be concluded that P. australis adopted a competition strategy during the early growth stage but took on a defense life strategy at the late growth stage to cope with various environments. [ABSTRACT FROM AUTHOR]

• Normative, information and technology factors collectively constrain adaptation action. • The adaptation barriers and needs of various livelihood farmers are different. • Satisfying livelihood needs is key to mitigating barriers for rural adaptation in developing countries. • Identifying adaptation barriers and requirements can help governments develop scientific and appropriate adaptation policies. • Interaction and dynamic changes of adaptation barriers will be the focus of future research. Systematically identifying the barriers and requirements to adaptation is critical to the successful implementation of climate adaptation planning and policies at the local level, especially in the mountainous rural communities of developing countries with limited resources and technology. We conducted an empirical study of the barriers and requirements to adapting to climate change of 539 peasant households in an ecologically vulnerable area of China to enhance their resilience to climate change by improving our understanding of adaptation process and decision-making. Our findings indicated that farmers in the Gannan Plateau face multiple adaptation barriers, of which normative, information and technology barriers were more serious, such as lack of meteorological information service, infrastructure and technology extension in agriculture or animal husbandry. Adaptation requirements are an important way to effectively reduce or eliminate obstacles and improve farmers' adaptive capacity to climate change. The survey found that local households have an urgent requirement for infrastructure, information and production technologies, such as water, electricity, transportation facilities, disaster warning information, employment information and farming or breeding techniques. In addition, due to the influence of economic level, education level, years of farming, gender and other factors, differences exist in the adaptation barriers and requirements faced by farmers in different regions. These findings extend empirical evidence in favor of formulating a reasonable adaptation framework and choosing optimal adaptation strategies, which are essential for enacting well-targeted regional adaptation policies. [ABSTRACT FROM AUTHOR]

Land use and cover change (LUCC) is an important issue affecting the global environment, climate change, and sustainable development. Detecting and predicting LUCC, a dynamic process, and its driving factors will help in formulating effective land use and planning policy suitable for local conditions, thus supporting local socioeconomic development and global environmental protection. In this study, taking Gansu Province as a case study example, we explored the LUCC pattern and its driving mechanism from 1980 to 2018, and predicted land use and cover in 2030 using the integrated LCM (Logistic-Cellular Automata-Markov chain) model and data from satellite remote sensing. The results suggest that the LUCC pattern was more reasonable in the second stage (2005 to 2018) compared with that in the first stage (1980 to 2005). This was because a large area of green lands was protected by ecological engineering in the second stage. From 1980 to 2018, in general, natural factors were the main force influencing changes in land use and cover in Gansu, while the effects of socioeconomic factors were not significant because of the slow development of economy. Landscape indices analysis indicated that predicted land use and cover in 2030 under the ecological protection scenario would be more favorable than under the historical trend scenario. Besides, results from the present study suggested that LUCC in arid and semiarid area could be well detected by the LCM model. This study would hopefully provide theoretical instructions for future land use planning and management, as well as a new methodology reference for LUCC analysis in arid and semiarid regions. [ABSTRACT FROM AUTHOR]

Gullies of different scales and types have developed in the Loess Plateau, China. Differences in the amount of gully erosion influence the development, evolution, morphology, and spatial distribution of these gullies. The strengths of headward erosion on the gully shoulder line are used to dictate soil and water conservation measures. In this study, six typical loess landforms in the Loess Plateau were selected as sampling sites: Shenmu, Suide, Ganquan, Yanchuan, Yijun, and Chunhua, which respectively represent loess–aeolian and dune transition zones, loess hills, loess ridge hills, loess ridges, loess long-ridge fragmented tablelands, and loess tablelands. Using 5 m resolution digital elevation model data from the National Basic Geographic Information Database, a small representative watershed was selected from each sampling site to obtain elevation data on the terrain profiles of gully shoulder lines. Multifractal detrended fluctuation analysis (MF-DFA) was used to conduct statistical and comparative analysis of the elevation fluctuation characteristics of these profiles. The results show that MF-DFA is capable of detecting active gully erosion sites. Sites of active gully erosion are concentrated in Shenmu and Suide but more widely distributed in the other five sites. The results provide a scientific basis for small watershed management planning and the design of soil and water conservation measures. [ABSTRACT FROM AUTHOR]

The practice of crop rotation can significantly impact carbon sequestration potential. In exploring whether crop rotation has the potential to improve soil carbon sequestration in China's Loess Plateau, soil organic carbon (SOC), soil water content (SWC), soil bulk density (SBD), and soil pH were compared across the 0–1.0 m soil profile, under four crop rotation patterns: lentil–wheat–maize, wheat–potato–lentil, wheat–maize–potato, and wheat–flax–pea. The lentil–wheat–maize and wheat–maize–potato rotations have been practiced over the past 20 years, while the wheat–potato–lentil and wheat–flax–pea rotations were established in 1978 (~40 year rotations). The results showed that under the 20-year lentil–wheat–maize rotation, SOC was not significantly different to that of the wheat–maize–potato rotation, at 6.81 g kg−1 and 6.91 g kg−1, respectively. However, under the lentil–wheat–maize rotation, SWC (9.81%) and SBD (1.19 Mg m−3) were significantly higher, but soil pH (8.42) was significantly lower than the same metrics under wheat–maize–potato rotation (8.43% and 1.16 Mg m−3, and 8.50, respectively). For the 40-year rotations, SWC (9.19%) and soil pH (8.41) under the wheat–potato–lentil were not significantly different to that of the wheat–flax–pea (8.87%, and 8.40, respectively). SOC (6.06 g kg−1) was significantly lower, but SBD (1.18 Mg m−3) was significantly higher under the wheat–potato–lentil than the wheat–flax–pea (7.29 g kg−1, and 1.15 Mg m−3, respectively) rotations. Soil carbon sequestration for the lentil–wheat–maize and wheat–potato–lentil rotations was co-influenced by SWC, SBD, and soil pH, while for wheat–maize–potato and wheat–flax–pea rotations, it was co-influenced by SWC and soil pH. The economic value of the four studied crops is, in order: potato > maize > wheat > flax. The results of the present study suggest that the lentil–wheat–maize and maize–flax–pea rotations are the most suitable patterns to optimize simultaneous economic and ecological development of the study area. [ABSTRACT FROM AUTHOR]

Since there are many destructive effects caused by extreme climate events in the Yellow River, it is of great theoretical and practical significance to explore the variations of climatic extremes in this key basin. We used a meteorological dataset from 66 stations within the Yellow River basin (YRB) for the period 1960–2017 to calculate magnitude and frequency of precipitation/temperature extremes. We also analyzed the relationships between the main large-scale atmospheric circulation patterns (ACPs) and precipitation/temperature extremes. The trends in precipitation extremes were nonsignificant, only a few stations were characterized by significantly increasing or decreasing anomalies; this indicates the precipitation intensity may have been strengthened, and the extreme rainfall duration appears to have been reduced during 1960–2017. The trends of magnitudes for "cold" extremes were larger than those for "warm" extremes, changes of trends in frost days were higher than those for summer days, and the trends in increasing warm nights were higher than those of warm days. The influence of the El Niño–Southern Oscillation (ENSO) and Arctic Oscillation (AO) on temperature extremes outweighed the influence of the North Atlantic Oscillation (NAO), Indian Ocean Dipole (IOD), and Pacific Decadal Oscillation (PDO) for the other extreme climate indices. The YRB might be at risk of increased extreme high temperature events, and more attention should be paid to this higher risk of extreme climatic events. [ABSTRACT FROM AUTHOR]

Slope aspect can affect soil temperature and soil type distribution, which, in turn, is likely to influence plant community composition. Three Qilian mountains, located in the northeastern part of the Qinghai–Tibetan Plateau, China, with four distinct slope aspects including south‐facing (SF), southwest‐facing (SW), northwest‐facing (NW), and north‐facing (NF) slope aspects, were studied to investigate the impact of slope aspect on plant assemblages. The results indicated that the environmental conditions were favorable under the NF and NW slope aspects as the soil water, soil organic carbon (SOC), and soil total nitrogen (STN) contents were significantly higher, and soil temperature (ST) and soil bulk density (SBD) were significantly lower than under the SF and SW aspects. Under all slope aspects, however, SOC, STN, and soil total phosphate in the top 0.2 m of topsoil accounted for about 60% of its total quantity, to a soil depth of 0.6 m. The plant communities on the SF and SW slopes were found to be primarily composed of Poa pratensis, Potentilla anrisena, and Carex aridula. In contrast, the plant community on the NW slope was mainly composed of Kobresia humilis, Carex crebra, and Potentilla bifurca, while on the NF slope it was mainly composed of Picea crassifolia, Carex scabrirostris, and Polygonum macrophyllum. The order of the influence of environmental factors on species distributions was ST > SBD > sand > STN. Results suggest that the slope aspect has an important role in the regulation of the soil environment and plant assemblages and that ST and SBD were the main factors influencing plant community composition. Furthermore, evidence from this study suggests that these mountains will become increasingly vulnerable to global warming. Thus, the plant community composition on these mountains must be monitored continuously in order to allow for strategic adaptive management. [ABSTRACT FROM AUTHOR]

The Returning Farmland to Forest Program (RFFP) was implemented in China in 1999 with the goal of supporting environmental restoration by returning significant areas of cultivated land to forest. While afforestation supports long-term ecosystem services like carbon sequestration and the reduction of soil and water loss, it also reduces the amount of available arable land, putting financial pressure on those who depend on it for their livelihoods. In an effort to balance both ecological and economic benefits, regional governments offer financial compensation to farmers to offset these pressures in the form of a dollar amount per hectare of reforested land. The current study explores participants' willingness to accept pay (WTA), along with the difference between the offered per hectare compensation and the amount deemed acceptable by RFFP participants in the region. To this end, 92 households from the representative afforestation area were surveyed in Huining County, Gansu Province, China - an area of strategic ecological importance in the Loess Plateau. The results showed 12.0% of the surveyed respondents to be satisfied with the current compensation policy, while 88.0% of respondents were not. The respondents' lower and upper WTA limits were $221/ha/year and $1331/ha/year, respectively, with an average WTA of $777/ha/year. The compensation that respondents would be most willing to accept was distributed in the $444–888/ha/year and the $889–1331/ha/year ranges, accounting for 37.0% and 31.5% of the total responses, respectively. Gender, age, and education were found to be the main factors influencing a respondents' WTA. Results of the survey suggest that the actual compensation amount ($355/ha/year) is much lower than respondents' WTA, and that compensation measures and policies should be improved to guarantee a basic income. [ABSTRACT FROM AUTHOR]

To understand the intricacies of nutrient cycling and advance grassland restoration strategies, this study delves into the varying responses of leaf, litter, and root ecological stoichiometries to different durations of grazing exclosure (GE) on the ecologically vital Qinghai-Tibetan Plateau in eastern China. The investigation encompassed GE durations of 0 (seasonal grazing), 13, 22, and 39 years, revealing pivotal alterations in ecological stoichiometries. Notably, GE markedly augmented leaf and root carbon (C) levels and the carbon to nitrogen (C:N) ratio, while diminishing leaf and root nitrogen (N), and root N to phosphorus (N:P) ratios. Intriguingly, with prolonged GE, root C and C:N exhibited a minor decline, and root N slightly increased, albeit remaining significantly lower than in seasonally grazed areas. Leaf N, along with litter P, C:P, and N:P ratios, displayed remarkable stability over time. This suggests that ecological stoichiometries of different plant components responded differently to GE duration. Across plant components, soil NH 4 + N emerged as a predominant factor influencing their stoichiometries, underscoring the complex interplay between vegetation and soil. There was the interconnectedness of C, N, and P among leaf, litter, and roots, highlighting understanding of these elements' cycles. This research, the first of its kind to assess the impact of extensive GE durations on leaf, litter, and root ecological stoichiometries on the Qinghai-Tibetan Plateau, offers insights for understanding ecological stoichiometries at the ecosystem level or between the above-ground part and below-ground part and for alpine grassland management. • Response of leaf, litter, and root stoichiometries to GE durations was examined. • Leaf and root stoichiometries were relatively sensitive to GE durations. • Leaf and root C and C:N increased but N and P decreased as GE duration extended. • Litter P, C:P, and N:P varied little across GE durations. • Leaf, litter, and root ecological stoichiometries were mainly regulated by NH 4 + N. [ABSTRACT FROM AUTHOR]

On China's Loess Plateau (CLP), shifts in land use are particularly influential in altering soil microbial communities. While one might expect shifts between grassland, forest and arable land to affect soil microbial communities, the specific ensuing responses of bacterial and fungal diversity and composition on the CLP are poorly understood. Soil microbial diversity and composition among the CLP's native grasslands, afforested lands, and 'abandoned' arable lands (fallow roughly 10 years in 2020) were determined using high-throughput sequencing of 16S rRNA and ITS genes. A comparison of land use types showed the abandonment of arable land and grassland afforestation to have had a negligible impact on soil bacterial α-diversity but to result in significantly lower soil fungal diversity. Grassland afforestation also increased fungal richness. Both bacterial and fungal β-diversity differed significantly among the land uses. Conversion of grassland to abandoned land significantly altered the relative phylum-level abundance of bacteria (except that of the Acidobacteria), but not that of fungal phyla. Grassland afforestation only influenced the abundance of bacteria and fungi of lower relative abundance (<10 % except Proteobacteria). The quantity of above- and below-ground biomass and soil properties explained most of the variation in soil microbial communities. Having important ecological implications, these findings can inform land management decisions in the study area and similar ecologically-fragile regions. • Grassland conversions altered soil fungal but not bacterial α-diversity. • Grassland conversions affected soil microbial β-diversity. • Grassland converted to abandoned land remarkably changed soil bacterial composition. • Grassland afforestation only affected bacteria and fungi with low relative abundance. • Soil texture played a crucial role in altering soil microbial β-diversity. [ABSTRACT FROM AUTHOR]

Topography has an influence on both abiotic (e.g. soil) and biotic (e.g. vegetation) factors influencing soil organic carbon (SOC). In this study, three slope aspects, south-facing, semi-sunny (south-west), and semi-shady (north-west) of mountainous grassland in the middle of the Qilian Mountains were sampled to explore the variation in SOC caused by topography. Soil properties were analyzed at different depths (0–10, 10–20, 20–40, and 40–60 cm). The results showed that except soil total organic phosphate, SOC, soil water content, soil bulk density, daily soil temperature, biomass, vegetation cover, and species richness on the semi-shady slope aspect were significantly different to those on two other slope aspects. The SOC, vegetation cover, and biomass significantly increased, from the south-facing to semi-shady slope aspect, and their values on the semi-shady slope aspect were around two times greater than on the south-facing slope aspect. The plant community composition also varied by slope aspect, with Agropyron cristatum and Stipa grandis dominant on the south-facing slope aspect, and Agropyron cristatum and Carex aridula dominant on the semi-sunny slope aspect, and Kobresia humilis and Carex crebra dominant on the semi-shady slope aspect. Among all measured abiotic and biotic factors, daily soil temperature, soil bulk density and total soil organic nitrogen could be used to predict SOC, explaining 69.0% of the variation in the data ( p < 0.001). On all slope aspects, SOC was greatest in the top 20 cm of soil, representing around 60.0% of the total SOC to 60 cm depth. The results indicated that the distribution of SOC was regulated by slope aspect through its influence on vegetation and soil properties in this region. Therefore, SOC protection measures should be aspect specific. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we analyze market efficiency for the Shanghai stock market over time using a model-free method known as multifractal detrended fluctuation analysis. Through analyzing the change of scale behavior, we find that the price-limited reform improved the efficiency in the long term, but the influence in the short term was very minor. Employing the method of moving window, using three different measures we find that the Shanghai stock market became more and more efficient after the reform. We also implement the same procedure on volatility series and find the evidence of inefficiency. [Copyright &y& Elsevier]

On China's Loess Plateau, where the distribution of soil organic carbon (soil − C org) is mainly influenced by topography, afforestation is an important strategy to sequester carbon and reduce soil erosion. To explore the effects of topography on soil − C org , soil samples were obtained at six depths (0–0.1 m, 0.1–0.2 m, 0.2–0.4 m, 0.4–0.6 m, 0.6–0.8 m, and 0.8–1.0 m) from locations on the Loess Plateau which had supported apricot (Prunus armeniaca L.) growth for 16 years and differed in slope aspect (sunny or semi-sunny vs. shady or semi-shady) and gradient (14° ≤ S < 20°, 20° ≤ S < 25°, or 25° ≤ S ≤ 31°). Across a depth of 1.0 m, the mean soil − C org and total soil carbon storage (soil − C tot) under the shady slope were 7.23 g kg−1 and 77.41 Mg ha−1, respectively; while under the sunny slope, these were 6.81 g kg−1 and 74.22 Mg ha−1, respectively. Both the soil − C org and soil − C tot increased with slope gradient, with soil − C org rising from 6.68 g kg−1 to 7.01 g kg−1, and to 7.34 g kg−1, and soil − C tot changing from 72.60 Mg ha−1 to 75.35 Mg ha−1, and to 79.40 Mg ha−1, respectively. Slope aspect and gradient interacted in influencing soil − C org , but not soil − C tot. Across both slope aspect and gradient, roughly half of soil − C tot was found within the first 0.4 m depth of soil. Overall a steep shady slope (vs. sunny gentle slope) was more favorable to the preservation of soil − C org , and would, accordingly, be of greater importance with respect to soil − C org protection and implementation of afforestation policy on the Loess Plateau and similar fragile environments worldwide. • About 50% of soil carbon was stored in the 0–0.4 m soil layer. • Afforestation under shady slopes maintained more soil carbon. • Afforestation on higher slope gradients maintained more soil carbon. • Slope aspect and gradient interacted to influence soil carbon. [ABSTRACT FROM AUTHOR]

Using next-generation sequencing technology alone, we have successfully generated and assembled a draft sequence of the giant panda genome. The assembled contigs (2.25 gigabases (Gb)) cover approximately 94% of the whole genome, and the remaining gaps (0.05 Gb) seem to contain carnivore-specific repeats and tandem repeats. Comparisons with the dog and human showed that the panda genome has a lower divergence rate. The assessment of panda genes potentially underlying some of its unique traits indicated that its bamboo diet might be more dependent on its gut microbiome than its own genetic composition. We also identified more than 2.7 million heterozygous single nucleotide polymorphisms in the diploid genome. Our data and analyses provide a foundation for promoting mammalian genetic research, and demonstrate the feasibility for using next-generation sequencing technologies for accurate, cost-effective and rapid de novo assembly of large eukaryotic genomes.