Area Of Inner Mongolia Research Articles

Fault Activity in Clay Rock Site Candidate of High Level Radioactive Waste Repository, Tamusu, Inner Mongolia

Tamusu area in Inner Mongolia is one of the favorable site candidates for high level radioactive waste (HLW) repository, which requires a stable regional tectonic environment. Field investigation, mossbauer spectroscopy, major elements, carbon and oxygen isotope and quartz micro morphology of fault gouge and host rock of three faults in the site candidate were conducted. The results show that the F2 and F7 faults on the north and south sides of the site candidate are in a relatively stable state with good sealing and weak activity. Part of the F4 fault is located in the site candidate, and the deportment of a small amount of pyrite in the fault zone and the difference of carbon and oxygen isotopes indicate that it may have experienced material exchange with the deep zone. Attention should be paid to induced earthquake risk.

Analysis of airborne allergens in chronic urticaria with airway allergic diseases

To analyze the sensitization characteristics and significance of airborne allergens in chronic urticaria (CU) with airway allergic diseases (allergic rhinitis and/or asthma). From May to August 2015, the Department of allergy, Beijing Shijitan Hospital Affiliated to Capital Medical University conducted an epidemiological survey of allergic diseases in grassland area of Inner Mongolia by multistage stratified cluster sampling. The results of skin prick test (SPT) for airborne allergens in 191 patients with CU and 1 132 patients with airway allergic diseases were analyzed. The statistical data were tested by chi-square segmentation method, and the stratified trend of rate was tested by Linear-by-Linear. Among the 191 patients with CU, 92 (48.17%) had CU without airway allergic diseases (CU alone), and 99 (51.83%) had CU with airway allergic diseases. The top three air allergens were house dust mite, chenopodium pollen and salix pollen in CU alone (only one is the major local allergen), and artemisia, humulus scandens and chenopodium pollen in CU with airway allergic diseases (All are the main local allergens) and airway allergic diseases. Compared between CU alone and CU with airway allergic disease, the positive rate of allergen SPT and multiple strong positive rate were statistically significant (59.60% vs 38.04%, χ²=13.336;27.12% vs 2.86%, χ²=8.729;P<0.016 7).There was no significant difference in positive rate of skin prick, multiple positive rate, strong positive rate and multiple strong positive rate between CU with airway allergic disease and airway allergic diseases (59.60% vs 57.69%, χ²=0.136, P>0.016 7; 71.19% vs 75.20%, χ²=0.461, P>0.016 7; 54.24% vs 69.68%, χ²=5.969, P>0.016 7; 27.12% vs 37.83%, χ²=2.663, P>0.016 7), but there was significant difference in these between CU without airway allergic disease and airway allergic diseases (38.04% vs 57.69%, χ²=13.336, P<0.01; 51.43% vs 75.20%, χ²=9.745, P<0.01; 28.57% vs 69.68%, χ²=25.624, P<0.01; 2.86% vs 37.83%, χ²=17.620, P<0.01).The strong positive rate and the multiple strong positive rate of allergen increased with the increase of CU with allergic diseases, and the trend difference was statistically significant (38.04%,56.98% and 76.92%, χ²=10.601, P<0.01; 28.57%,46.94% and 90.00%, χ²=12.085, P<0.01; 2.86%,24.49% and 40.00%, χ²=10.077, P<0.01). The allergen sensitization characteristics of CU with airway allergic diseases are similar to airway allergic diseases,and the detection of airborne allergens may have certain clinical value in the screening of risk factors for patients with CU associated with airway allergic diseases.

First report of alfalfa leaf spot caused by Leptosphaerulina australis in China.

A disease was observed on alfalfa cultivar WL168 characterized by white to brown leaf spots of regular to round shapes, in Aluhorqin County, Inner Mongolia, China (120°13'23″ to 120°29'14″ E, 43°27'52″to 43°35'16″ N, 281.71m to360.13 m Altitude) during 2019 to 2020. The disease mainly presented in spring one month after re-greening and the incidence was 78.30% in this field. Twenty alfalfa plants with severe symptoms were used for pathogen isolation. The infected tissue was cut into 2 × 2 mm pieces, surface-sterilized (in 75% ethanol and 5% commercial bleach (NaClO) for 30 s and 2 min, respectively), rinsed five times with sterilized distilled water, and dried between sterile filter paper (Wang et al. 2019). The diseased tissue from each plant sample were cultured on potato dextrose agar (PDA) and incubated at 25 °C with 12 h light/day for ten days. A fungus was isolated from the diseased leaves at a 100% frequency. Fungal growth on PDA was round with a black surface, radial edge, and a dirty white center. The ascocarps were moved to a clean microscope slide to release asci and ascospores. Ascocarps were spheroidal, subglobose brown, 120 to 160 µm × 160 to 180 µm, which contain several ascus. The size of ascus were 31.0 to 41.6 μm × 75.0 to 87.5 μm and each asci having eight ascospores. Ascospores were ellipsoid to oblong with a gelatinous sheath, brown, 8.8 to 15.0 µm × 29.9 to 43.0 µm with 2 to 3 horizontal septums, and 0 to 2 vertical septums. A phylogenetic tree was constructed after DNA extraction, PCR with primers to amplify the ITS (VG9: 5'- TTACGTCCCTGCCCTTTGTA-3' and ITS4: 5'-TCCTCCGCTTATTGATATGC-3') and LSU (LR7: 5'-TACTACCACCAAGATCT-3' and LROR: 5'- GTACCCGCTGA ACTTAAGC -3') regions. The LSU (SUB8273071) and ITS (SUB8218291) amplicons showed 99% similarity with L. australis (EU754166.1) in the GenBank. To verify the pathogenicity, fungs plugs were inverted on three compound leaves of 20 alfalfa WL168 for two days. Agar plugs (PDA) were inverted on another 20 alfalfa WL168 three compound leaves which were control. All plants were maintained at 22 °C and 44% relative humidity in a growth chamber. Similar disease symptoms were observed on infected leaves ten days after inoculation, while control plants showed no symptoms. The same fungus was re-isolated from the lesions, and further morphological characterization and molecular assays, as described above. L. australis has been reported on various plants, including Prunusarmeniaca, Dolichos, Poa, Lolium, and Vitis in Australia (Graham and Luttrell., 1961), and also from Korean soil in 2018 (Weilan et al., 2018). Additionally, L. briosiana, which is common in the USA, China, and other countries, causes Leptosphaerulina leaf spot (Samacet al., 2015). L. trifolii is newly reported to occur in China (Liu et al., 2019). To the best of our knowledge, this is the first report of L. australis infecting alfalfa in China. Considering the large planting area in Inner Mongolia, this pathogen may losses to alfalfa cultivation. Hence, future studies should explore aspects of effective management of this disease.

Current Status and Challenges of the Ecological Environment of Wuliangsuhai Basin in China

Lake ecological security refers to maintaining the integrity and ecological health of the lake ecosystem under the influence of human activities, providing humans with stable ecological service functions, and preventing ecological catastrophes. In the lake ecosystem, lakes are the main body, and their water ecological health is the basis of system security. Therefore, the ecological safety and health of lakes are investigated, and the multi-faceted evaluation system of lake ecological safety is established, which can provide decision-making basis for lake management and pollution control. It is of great significance for the sustainable management of lake ecosystem and the rational utilization of resources to coordinate the environmental, social and economic benefits of relevant departments. Wuliangsuhai Lake is the largest natural wetland in the same latitude area in the world, and the eighth largest freshwater lake in China. It is the most typical shallow-water grass-algae lake in the arid area of Inner Mongolia. It is an important water conservation, storage, and water transfer site in the upper and middle reaches of the Yellow River. It is also a large grass-algae lake with biological diversity and ecological function, which is extremely rare in desert and semi-desert areas in the world. This article briefly introduces the main ecological and environmental problems and their causes in the Wuliangsuhai Basin.

A study of the insulating and anti-frost heave effects of polystyrene boards under molded bag concrete conditions

Abstract In this study, the channel frost heaving actions in the Hetao irrigation area of Inner Mongolia were examined and a field in-situ test platform was established. Then, experimental investigations were conducted regarding the insulating and anti-freeze effects of polystyrene boards under the conditions of concrete bags with different thicknesses. In this study's experiments, concrete bags with different thicknesses were set, along with a test block of polystyrene boards with different thicknesses. The research results showed that by adding 2–5 cm molded bags, the total accumulated temperature increased in the range of 3.93–9.22% and the frost heave rate decreased by between 18.28 and 55.44% concrete, on the basis of 10 cm molded bag concrete. In addition, when 4–8 cm polystyrene boards were laid, the total accumulated temperature increased by 207.63–272.25%, and the frost heave rate decreased by between 71.43 and 96.6%. The absolute slope of the curve fitting of the frost heave rates and the soil temperatures decreased by 44.6–58.7%.

Climate and Anthropogenic Influences on the Spatiotemporal Change in Degraded Grassland in China

Grassland ecosystems in China are generally fragile, and have suffered severe degradation and desertification in recent decades. Understanding these changes and their drivers is crucial for projecting ecosystem dynamics. This study investigated the spatiotemporal variation of grasslands in China, and quantitatively assessed the influence of natural and anthropogenic factors using net primary productivity (NPP) from 2000 to 2014. The results showed a net increase in total grassland area of 1.30 × 105 km2, and the annual NPP increased significantly from 119.37 to 140.67 g C/(m2·a). Restored grassland dominated the research area, but the spatial distribution of grassland health was highly heterogeneous. Climate change contributed most to the recovery of degraded grasslands, especially in Inner Mongolia and Qinghai, where it was the dominant influence for 83.21% and 87.06% of the total grassland areas, respectively. Meanwhile, human activities contributed to the mitigation of grassland degradation in Tibet and Xinjiang. The opposite occurred in some localized areas of Inner Mongolia and Xinjiang. This suggested that restoration projects should be tailored to alleviate local grassland retrogression and adapt to unexpected events such as concentrated degradation.

AN UNSUPERVISED METHOD BASED ON FIRE INDEX ENHANCEMENT AND GRNN FOR AUTOMATED BURNED AREA MAPPING FROM SINGLE-PERIOD REMOTE SENSING IMAGERY

Abstract. In the current situation of frequent forest fires, the study of forest burned area mapping is important. However, there is still room for improvement in the accuracy of existing forest burning area mapping methods. Therefore, in this paper, an unsupervised method based on fire index enhancement and GRNN (General Regression Neural Network) is proposed for automated forest burned area mapping from single-date post-fire remote sensing imagery. The proposed method first uses adaptive spatial context information to enhance the generated fire index to improve its ability to indicate the burned areas. Then the uncertainty analysis is performed on the enhanced fire index to extract reliable burned samples and non-burned samples for subsequent classifier training. Finally, the improved GRNN model considering the spatial correlation of pixels is used as a classifier to binarize the enhanced fire index to generate the final burned area map. Based on two commonly used fire indexes, NBR (Normalized Burn Ratio) and BAI (Burned Area Index), this paper conducts burned area mapping experiments on a post-fire image of a forest area in Inner Mongolia, China to test the effectiveness of the proposed method, and two commonly used threshold methods (Otsu and Kmeans clustering) are also used to conduct burned area mapping based on threshold segmentation of fire index for comparison experiments. The experimental results prove the effectiveness and superiority of the proposed method. The proposed method is unsupervised and automated, so it has high application value and potential under the current situation of frequent forest fires.

Assessment of wind energy resources in the urat area using optimized weibull distribution

Accurate assessment and analysis of wind energy resources are the key to wind farm planning. In this study, we evaluate the wind energy resource potential in the Urat area of Inner Mongolia, China, based on data measured from four 70–100 m/s wind tower. We first model the wind speed by the Weibull distribution where the parameters are estimated by various numerical and intelligent optimization methods. In particular, we introduce the Cross Entropy Method (CEM) and find that it outperforms other methods. Based on the Weibull model, we then evaluate six wind energy metrics for the Urat area. It is shown that the annual average wind speed and wind power density are up to 9.33 m/s and 941 W/m2, respectively, with over 7000 h of annual available time. The wind is relative stable for all seasons except for a mild reduction in speed and a change of direction in summer. The low power production cost and rapid payback period make the Urat area a promising location for deploying wind farms.

Environmental Risk Assessment for PM2.5 Pollution from Non-Point Sources in the Mining Area Based on Multi-Source Superposition and Diffusion

To identify high-concentration contributing sources and highly dispersive pollution sources of fine particulate matter, analyze the relationship between the location and distribution shape of emission sources and the concentration contribution and dispersion of particulate matter, and realize the atmospheric environment risk simulation and the differential control of non-point sources in the mining area, taking a large mining area in Inner Mongolia as an example, we classified the emission sources of PM2.5 (particulate matter less than 2.5 μm) and complied with the emission inventory. A CALPUFF model was used to simulate the contribution for the PM2.5 concentration of six types of emission sources and a multi-source superposition. Through scenario simulation, we analyzed the relationship between the spatial distribution of emission sources and the emission concentration and diffusion in a large mining area. We analyzed the relative risks of six types of sources under the influence of other superimposed sources and the change of emission concentration during transmission. We established a three-dimensional evaluation model to assess the atmospheric environmental risk of PM2.5 non-point sources in the mining area, considering the change rate of PM2.5 concentration with migration, the relative contribution ratio of superimposed sources, and the equal contribution index of the standard concentration. The results show that the maximum equal contribution index of standard concentration of multi-source superposition was 4.40. Among them, non-paved roads, exposed surface sources of coal piles, and exposed surface sources of mine pits and dumps were the top three pollution contributors, and their maximum equal contribution indexes of standard concentration were 2.40, 2.21, and 2.10, respectively. The effect of superimposed pollution sources was affected by the wind field and the spatial distribution density of emission sources, while the dispersion was affected by the wind direction and the distribution direction of pollution sources. In the case of the same source intensity and emission area, the denser the source distribution was, the higher the emission concentration was, the smaller the contribution ratio of superimposed sources was, and the greater the relative pollution risk was. When the angle between the direction of dispersed linear pollution sources and the dominant wind direction was smaller, the emission concentration was higher, but the diffusion surface was smaller. When the angle with the direction of wind direction was larger, the emission concentration was lower, but the diffusion surface was larger. Concentrated pollution sources had the highest concentration and the diffusion surface was in the middle. Non-paved roads had the highest environmental risk, with an average risk of 5.61 × 10−2, followed by coal piles with an average value of 2.06 × 10−2, followed by pits and dumps with an average value of 1.89 × 10−2; the environmental risk of loading and unloading sources was the lowest. Unpaved roads were pollution sources with high relative pollution risk and diffusion risk, and their average relative pollution risk and diffusion risk were 2.34 × 10−2 and 3.28 × 10−2, respectively. In the case of multi-source superposition, the high-risk areas were mainly heavily polluted areas with intensive emission sources, while the medium-risk areas were moderately polluted areas with scattered pollution sources, and the diffusion risk was high. This research concludes that the dispersed distribution of pollution sources can reduce pollution risk, and the smaller the angle is between the linear distribution direction of pollution sources and the dominant wind direction, the smaller the diffusion risk is. Therefore, differentiated control can be carried out according to the characteristics of pollution sources. The conclusions can provide methods and theoretical support for the control of atmospheric environment risk, pollution prevention, and control planning in mining areas.

Effects of shrub-grass patterns on soil detachment and hydraulic parameters of slope in the Pisha sandstone area of Inner Mongolia, China

Effects of shrub-grass patterns on soil detachment and hydraulic parameters of slope in the Pisha sandstone area of Inner Mongolia, China

Impact of Cropland Evolution on Soil Wind Erosion in Inner Mongolia of China

Understanding soil erosion responses to cropland expansion/shrinking plays a crucial role in regional agriculture sustainability development in drylands. We selected Inner Mongolia, a typical water resource constraints region with acute cropland expansion, as the study area in China. Spatial cropland evolution and its impact on wind-driven soil erosion were investigated with the help of field sampling data, remotely sensed retrieved data, and the revised wind erosion model (RWEQ). Results showed that the cropland area of Inner Mongolia presented an increased growth trend, with a net increase area of 15,542.9 km2 from 1990 to 2018. Cropland characteristics in Inner Mongolia presented continuous growth in its eastern region, basically constant growth in its central region, and declined in its western region. Most cropland declines occurred after 2000 when the Grain for Green project began, which means that acute cropland expansion happened from 1990 to 2000. The soil wind erosion modulus showed a net increase with cropland expansion. The reclamation of forests and grasslands contributed to an increase of 5.0 million tons of the soil wind erosion modulus, 80% of which was produced in the eastern part of the region. The conversion from croplands to grasslands/forests caused a decrease of approximately 2.7 million tons, 62% of which was in the east and 25% in the west of the region. Considering the constraints of water shortage and over-exploitation of groundwater, we provide a path based on a balance between ”resource-production-ecosystem” to achieve ecologically sustainable agriculture development in the drylands of China.

Quantitative prediction of molybdenum-copper polymetallic mineral resources in the Xindalai grassland-covered area of Inner Mongolia based on geological anomalies

Quantitative prediction of molybdenum-copper polymetallic mineral resources in the Xindalai grassland-covered area of Inner Mongolia based on geological anomalies

A 168-year temperature recording based on tree rings and latitude differences in temperature changes in northeast China.

A ring-width series was developed from Dahurian larch (Larix gmelinii) in the northeastern forest area of Inner Mongolia, China. By analyzing the relationships between tree-ring data and climate records, an August-September mean maximum temperature (T89) series during 1845 and 2012 was reconstructed based on a simple linear regression equation. This reconstructed series explained 40.9% variance of the observed temperature from 1959 to 2012. The reconstructed T89 series was consistent with the historical disaster events caused by extreme climate (e.g., flood, frost disaster, and cold damage). Besides, the temperature comparisons showed that the year in which the warm months (April-September) in northeast China began to warm up has latitude differences. It started with a gradual delay from north to south, starting 1980 in the south region, after 1950 AD in the central region and after 1940 in the north region. Our study can enrich high-resolution temperature series in Northeast China and help clarify the characteristic of recent warming in northeast China.

Seasonal variation in soil temperature and moisture of a desert steppe environment: a case study from Xilamuren, Inner Mongolia

Soil temperature and moisture are important factors affecting vegetation growth and drought in desert steppe environments. These factors also strongly influence grassland ecosystems. This study interpreted long-term (2009–2019) ground observation data on soil temperature, soil moisture, and meteorological factors from a study area in Inner Mongolia. The monitoring station collected soil moisture, soil temperature, and precipitation data. Covarying relationships indicated how soil properties influence each other throughout the year. Soil temperature was clearly affected by atmospheric changes, solar radiation, and freeze/thaw processes. The surface soil layers showed the greatest degree of variation, while middle and lower layers showed less seasonal variation and smaller differences between daily highs and lows. Surface soil moisture correlates strongly with the vertical temperature decline in soil. Time series revealed major variation in soil moisture throughout the year with lower soil layers showing obvious hysteresis effects. Multi-year soil moisture data allowed for subdivision of the year into seven intervals based maximum and minimum values. Soil temperature showed unique patterns of covariation with soil moisture during different time periods. Differences in soil moisture cause more rapid changes in temperature during soil thawing relative the moisture-induced temperature changes observed 1 month after soil freezing. When soil temperature was greater than 0 °C (32 ℉), soil temperature and soil moisture showed inverse correlation. A dependency of evapotranspiration on soil temperature can explain its effect on soil moisture. When soil temperature fell below 0 °C(32 ℉), soil temperature and soil moisture showed a positive correlation. During an interval defined as the summer fluctuation (SF), precipitation and soil moisture showed a significant positive correlation. During other periods, soil moisture did not clearly covary with precipitation.

Early Permian continental arc magmatism in the Zhaojinggou area of the northern North China Craton: Implications for crust-mantle interactions during southward Paleo-Asian plate subduction

Early Permian magmatism in the Zhaojinggou area of Inner Mongolia, northern China produced intrusive gabbroic diorite and granites including biotite granite, K-feldspar granite and fine-grained granite. We present zircon U–Pb geochronology, whole-rock geochemistry, and Sr–Nd–Hf isotopic compositions of these rocks to resolve complex crust–mantle processes beneath the northern margin of the North China Craton (NCC). Zircon U–Pb dating reveals that the rocks were emplaced in the Early Permian, with gabbroic diorite (291.1 ± 1.8 Ma) forming ~10 Myr earlier than the granites (biotite granite, 280.0 ± 1.6 Ma; K-feldspar granite, 279.7 ± 2.1 Ma; fine-grained granite, 282.2 ± 2.9 Ma). Geochemical data indicate that the rocks have calc-alkaline to high-K calc-alkaline and metaluminous to peraluminous affinities, with enrichment in light rare-earth elements (LREE) and large-ion lithophile elements (LILE), and depletion in high-field-strength elements (HFSE), typical of continental arc magmatic rocks. The gabbroic diorite is characterized by low–moderate Mg# values (38–59, mean 50), moderate average Cr (45.0 ppm) and Ni (36.5 ppm) contents, and moderately enriched Sr–Nd–Hf isotopic compositions with (87Sr/86Sr)i values of 0.704719–0.705497; εNd(t) values from −7.8 to −7.0; and εHf(t) values from −11.2 to −6.7. These features, combined with highly variable Rb/Y, Ba/La, Th/Yb, Th/Ce and Th/Sm ratios and Ba contents, indicate that the gabbroic diorite was derived from subduction-related enriched sub-continental lithospheric mantle (SCLM), previously metasomatized by slab fluids and ~5% sediment melts. Weakly negative to strongly positive Eu anomalies among gabbroic diorite samples indicate no residual plagioclase accumulation or fractionation during magma evolution. The granites have similar ages and enriched isotopic features (87Sr/86Sri = 0.703611–0.707427; εNd(t) = −11.4 to −9.2; εHf(t) = −12.8 to −7.2) with old Nd and Hf model ages of 1980–1801 Ma and 1730–2088 Ma, respectively, indicating that they originated through partial melting of ancient mafic lower crust. Both biotite granite and K-feldspar granite exhibit weakly negative to highly positive Eu anomalies and relatively low Zr saturation temperatures of 618–648 °C. In contrast, the fine-grained granite has negative Eu anomalies and relatively high Zr saturation temperatures (692–709 °C). These features imply that the magma source of the fine-grained granite (with plagioclase accumulation) was deeper than that of the biotite granite and K-feldspar granites (without plagioclase accumulation). Different mantle and crustal sources involved in the generation of continental arc magmatism in the Zhaojinggou area have implications for extensive and complex crust–mantle interactions beneath the northern margin of the NCC related to southward subduction of the Paleo-Asian oceanic crust during the Early Permian.

Ecosystem services under different grazing intensities in typical grasslands in Inner Mongolia and their relationships

Grazing, as the main land use of grasslands, is a key factor affecting the supply of ecosystem services11ES, ecosystem service; GI, grazing intensity; CK, control check; LG, light grazing; MG, moderate grazing; HG, heavy grazing; BI, biodiversity; HI, herbage intake; CP, crude protein content; SOCD, soil organic carbon density; SMN, soil mineralization nitrogen; AB, aboveground biomass; BB, belowground biomass; LB, litter biomass; TES, total ecosystem services; SSU, standard sheep units. (ESs) as well as the relationships between ESs. Using four grazing intensities, including control check, light grazing, moderate grazing, and heavy grazing, this paper quantified eight key ESs, including biodiversity, herbage intake, herbage quality (herbage crude protein content), climate regulation (soil organic carbon density), soil mineralization nitrogen, soil conservation (aboveground biomass), wind prevention and sand fixation (belowground biomass), and soil erosion prevention(litter biomass), in typical grassland areas of Inner Mongolia. Structural equation models were used to illustrate the impact of grazing on ESs through biodiversity, and the root mean square error was used to quantify the level of trade-offs for ES pairs. The results of this study indicated that grazing intensity (GI) significantly affected all ESs (p < 0.05), except for soil organic carbon density and soil mineralization nitrogen. As GI increased, provisioning services increased, while most regulating services decreased, and there was a general trade-off relationship between regulating services and other ones. In order to realize the maximum ESs benefit and the minimum trade-offs for ES pairs, the optimal grazing intensity for typical grasslands of Inner Mongolia should be between 170 (standard sheep units) SSU · d · hm−2 · y−1 and 340 SSU · d · hm−2 · y−1. The results of this study provide a decision-making foundation for grassland grazing management policies for the sustainable development of Inner Mongolian grasslands.

Characterization of acidity and sulfate in dust obtained from the Wuda coal base, northern China: spatial distribution and pollution assessment.

The coal fire in Wuda, Inner Mongolia of China, is one of the most serious coal fires in the world with a history over 50 years and endangers the neighboring downwind urban area. A lack of effective measures to control coal fires in this region can aggravate environmental pollution. In this study, the levels and spatial distributions of acid (pH) and SO42- in dust in the Wuda coalfield and its surrounding areas in Inner Mongolia, North China, were reported to identify the potential acid and SO42- pollution in the local environment with an area of 270 km2. The mean pH and SO42- content was to found to be 7.44 and 5981 μg·g-1, respectively. Through the analysis of the spatial distribution of pH and SO42- concentrations, it was found that most of contaminated areas are mainly distributed in coalfield and its affiliated industrial parks, and the Wuda urban area also suffered from pollution. Based on chemical equilibrium, the surface acid pollution might have resulted in the change of the dust type from the original weakly alkaline CaCO3 type to the CaSO4 type in coalfield and industrial parks. Finally, the pollution assessment revealed that the coalfield and industrial parks are both at heavy pollution levels, and the urban area is mostly moderately polluted, followed by farm and peripheral region with a certain pollution risk. The results indicated that the long-term release of acidic gas from the coal fires and industrial parks can led to significantly elevated acidity and SO42- levels in the dust of the local environment, while coal fires can aggravate surface pollution in industrial parks, but the extent of contamination was also closely related to the terrain and wind direction in the study area.

An improved approach to estimate above-ground volume and biomass of desert shrub communities based on UAV RGB images

Above-ground biomass (AGB) is an essential indicator for assessing ecosystem health and carbon storage in desert shrub-related research. Above-ground volume (AGV) of vegetation is a crucial parameter to estimate the AGB. In unmanned aerial vehicle (UAV) remote sensing, the AGV and AGB are mainly estimated by vegetation feature metrics (for example, spectral indices, textural, and structural metrics). However, there is limited study on the AGV and AGB estimation in desert shrub communities by using UAV, and it is difficult to determine the contribution of these metrics to AGV models under eliminating the influence of background factors. Taking a typical desert shrub area in Inner Mongolia, China as an example, this study develops an improved approach to extracted three types of feature metrics simultaneously using UAV RGB (Red, Green, Blue) images. First, digital orthophoto map (DOM) and digital surface model (DSM) were created through the photogrammetric procedure based on UAV RGB images. Second, the digital terrain model (DTM) for canopy height calculation was generated based on DOM and DSM by object-oriented image binary classification and ground elevation interpolation. Here, we recommended the ENVI Landsat Gap-fill tool to interpolate the ground elevation of vegetation areas. Meanwhile, 21 spectral indices, eight textural metrics, and five structural metrics were extracted. Finally, single-variable and multi-variable commonly used regression models were established based on these metrics and measured AGV with a leave-one-out cross-validation. Results showed that: (1) in the proposed model, the contribution of structural, textural, and spectral metric to shrub AGV models was 86.68, 7.08, and 6.24%, respectively. (2) The horizontal and vertical structural metrics, textural metrics, or spectral indices reflected the one-dimensional change of AGV, which had a saturation effect. (3) The canopy volume, combining the horizontal and vertical characteristics of vegetation canopy, could describe the overall change of AGV and played the most essential role in AGV modelling (R2 = 0.928, relative RMSE = 26.8%). The study findings provide a direct reference in determining suitable vegetation feature metrics for monitoring shrub AGV. The proposed approach for DTM generation and AGV estimation is more efficient, accurate and low-cost than before, and it can be a useful bridge between ground-based investigation and satellite remote sensing.

Analysis of differences in chemical properties of reconstructed soil under different proportions of topsoil substitute materials.

The purpose of this study was to evaluate the soil substitutes in land reclamation following mining activities. This study revealed different reconstructed soil materials have different effects on the chemical properties of reconstructed soil and explored the appropriate proportions of reconstructed soil materials. Using topsoil, coal gangue, fly ash, and rock and soil stripping material from the Shengli Mining Area of Inner Mongolia in China as raw materials, potting experiments were carried out according to different proportions. The variance analysis method was used to analyze the difference in the soil pH values, soil organic matter (SOM) content, soil total nitrogen (STN) content, soil available phosphorus (SAP) content and soil available potassium (SAK) content of the reconstructed soil, and the reasons for the difference were discussed. The results showed that in the treatment group where the topsoil substitute material was coal gangue, when the coal gangue content was 30%, 40%, and 50%, the pH values of reconstructed soil were lower than that of the control scheme. When the coal gangue content exceeded 10%, the soil nutrient status was obviously improved. In the treatment group where the topsoil substitute material was fly ash, the chemical properties of reconstructed soil tended to deteriorate. In the treatment group where the topsoil substitute material was rock and soil stripping material, when the content of rock and soil stripping material exceeded 20%, the chemical properties of reconstructed soil were mostly better than those of the control scheme. The study of the different proportions of coal gangue, fly ash, and rock and soil stripping material as topsoil substitute materials provide support for reclamation work in mining areas where topsoil is scarce, as well as a reference for ecological restoration projects in grassland open-pit mining areas around the world.

Differences in microbial communities from Quaternary volcanic soils at different stages of development: Evidence from Late Pleistocene and Holocene volcanoes

Volcanic eruptions are a universal cause of ecological and geological disturbance; however, the differences in microbial communities from Quaternary volcanic soils at different stages of development in Inner Mongolia are little known. Microbial communities were investigated in Quaternary volcanic soils from Late Pleistocene volcano and Holocene volcano with the objective of elucidating their differences. The composition and potential functionality of soil microbial communities was significantly diverse between Late Pleistocene volcanic soils and Holocene volcanic soils. Although the richness, diversity and evenness of microbial communities at older volcanic soils were significantly greater than at younger volcanic soils, younger volcanic soils possessed a more complex microbial community network than older volcanic soils. The soil bacterial community was more sensitive to Quaternary volcanic soils than the fungal community, exhibiting significant differences at the phylum level and possessing more biomarkers. Quaternary volcanic soils may have enriched some specific microorganisms, i.e., biomarkers and generalists, closely related to the metabolism of soil carbon, nitrogen and phosphorus. Quaternary volcanic soils first directly mediated soil carbon, nitrogen and phosphorus, and then guided microbial multifunctionality. These results clarify the difference patterns of soil microbial communities in support of better ecological management of volcanic area in Inner Mongolia.