Northern Tianshan Research Articles

Source‐to‐sink systems in the Turpan Basin throughout the Jurassic: Constraints from detrital zircon geochronology

Source‐to‐sink system studies in oil fields are especially important for optimizing the favourable oil‐gas areas; however, this basin‐mountain interaction process is particularly complicated in intermontane basins. In this study, detrital zircon U–Pb dating of 8 new and 3 published samples from throughout the Jurassic in the central Turpan Basin (TB) are combined with collected heavy mineral data to investigate the evolution of the source‐to‐sink system and reconstruct the filling process of this intermontane basin from the Lower to Upper Jurassic. Based on the detrital zircon ages and heavy mineral assemblage, the filling rocks mainly weathered from Mesozoic, Palaeozoic and Precambrian volcanic and metamorphic rocks in the Tian Shan (TS) area, and the source‐to‐sink systems in the basin show a clear alteration corresponding to the uplift of the surrounding mountains during the Jurassic. In the Lower Jurassic, the uplifted central and northern TS was the main provenance and shed the most source rocks northward, and the gentle positive relief of the Bogda Mountains (BM), the northern boundary of the TB, was a secondary provenance and provided limited material to the northern area. In the early Middle Jurassic, these provenances did not alter much, but in the later Middle Jurassic, uplift of the western BM began and provided some extreme new source rocks with detrital zircon ages of approximately 159–172 Ma. In the Upper Jurassic, the considerably uplifted BM became the main provenance, while the still gently uplifted central and northern TS became the secondary provenance.

Burial and exhumation history of Jurassic sedimentary rocks in the southern margin of the Junggar Basin: Implications for the growth of the northern Tianshan Mountains

• Apatite fission-track dating yields 147–50 Ma for the Jurassic sedimentary rocks in the southern margin of Junggar Basin. • The Jurassic sedimentary rocks experienced two cooling stages at 150–110 Ma and the Late Miocene (20–10 Ma). • The exhumation of Jurassic sedimentary rocks was associated with the northward expansion of the Tianshan Mountains. • The two cooling stages had a wide range of regional dynamic responses in northwestern China. Constraining the burial and exhumation evolution of sedimentary basins is crucial for understanding the deformation histories of basin–mountain transition zones. The thick Jurassic sedimentary successions on the southern margin of the Junggar Basin are an essential archive of the uplift and deformation of the Tianshan Mountains. Apatite fission-track and vitrinite reflectance analyses were performed on the Jurassic sedimentary rocks bordering the northern Tianshan Mountains, providing direct insight into the burial and exhumation of the southern margin of the Junggar Basin. Our apatite fission-track data indicate four main cooling stages during 150–125 Ma; 120–105 Ma; 100–80 Ma; and 75–45 Ma. Thermal-history modeling results demonstrate that the Jurassic sedimentary rocks were exhumed in the northern Tianshan Mountains, indicating a history of probable Early to Middle Jurassic sedimentary burial followed by slow cooling commencing at approximately 150–110 Ma. Then, this region undergone gradual deplanation between the Late Jurassic–Cretaceous and the Miocene and rapid cooling since the Late Miocene (20–10 Ma). These two stages of cooling and exhumation are interpreted to reflect the accretion of the Lhasa Block and the India-Eurasia collision, respectively. Furthermore, the thermal history of the Jurassic sedimentary rocks is consistent with the sedimentation pattern and depositional environments in the southern margin of the Junggar Basin, providing complementary evidence for the time of exhumation and implying that denudation migrated into the Junggar Basin concurrent with uplift of the northern Tianshan Mountains.

Radial Growth of Picea schrenkiana Influenced by Increasing Temperature in the Tianshan Mountains

There is a tendency of warming and wetting in northwestern China in recent decades. However, less is known about whether or not tree growth shows an increasing trend. In this study, we developed three tree-ring width chronologies of Picea schrenkiana in the northern Tianshan Mountains to assess changes in the radial growth of P. schrenkiana and to discuss the stability of the relationships between tree growth and climate. Three chronologies all showed that the tree-ring index has declined significantly since the 1960s. At two western sites, the growth of P. schrenkiana was negatively affected by the summer temperature of the previous year. At the eastern site, early summer temperature-induced drought of the current year was the key factor affecting tree growth. The result of moving-window correlations was consistent with correlation analyses. Spatial correlation analyses revealed that variations in tree-ring width could respond to a wide range of temperature changes in northwestern China, especially in the past half century. We expect that climate warming hinders the radial growth of P. schrenkiana in the northern Tianshan Mountains. Our study also helps to clarify the characteristics of tree growth in northwestern China under the influence of westerlies.

Review on the Application of Airborne LiDAR in Active Tectonics of China: Dushanzi Reverse Fault in the Northern Tian Shan

High-resolution topographic data are fundamental for active tectonics studies. Within the last 2 decades, the airborne light detection and ranging (LiDAR) system provided a solution for the accurate and efficient acquisition of detailed geomorphic features. The use of LiDAR data for the identification of microstructural and geomorphic features, fault zone activity analysis, and earthquake disaster assessment remains challenging and has been the focus of active tectonics studies. Based on the LiDAR data of Dushanzi anticline–a reverse fault zone in Xinjiang, China, our group carried out a significant number of active tectonic research studies. By reviewing the specific content of these works, we summarized the main application of LiDAR for a specific structure, the Dushanzi Reverse Fault in the northern Tianshan. In addition, other applications of LiDAR in active tectonics are summarized in this paper. These studies show that high-resolution LiDAR data facilitate detailed studies of the fault activity and paleoseismicity. We hope more researchers can realize the advantages of LiDAR technology in active tectonics research and apply LiDAR technology into their own practical work, so as to promote the development of active tectonics research.

Spatiotemporal Distribution Patterns and Exposure Risks of PM2.5 Pollution in China

The serious pollution of PM2.5 caused by rapid urbanization in recent years has become an urgent problem to be solved in China. Annual and daily satellite-derived PM2.5 datasets from 2001 to 2020 were used to analyze the temporal and spatial patterns of PM2.5 in China. The regional and population exposure risks of the nation and of urban agglomerations were evaluated by exceedance frequency and population weight. The results indicated that the PM2.5 concentrations of urban agglomerations decreased sharply from 2014 to 2020. The region with PM2.5 concentrations less than 35 μg·m−3 accounted for 80.27% in China, and the average PM2.5 concentrations in 8 urban agglomerations were less than 35 μg·m−3 in 2020. The spatial distribution pattern of PM2.5 concentrations in China revealed higher concentrations to the east of the Hu Line and lower concentrations to the west. The annual regional exposure risk (RER) in China was at a high level, with a national average of 0.75, while the average of 14 urban agglomerations was as high as 0.86. Among the 14 urban agglomerations, the average annual RER was the highest in the Shandong Peninsula (0.99) and lowest in the Northern Tianshan Mountains (0.76). The RER in China has obvious seasonality; the most serious was in winter, and the least serious was in summer. The population exposure risk (PER) east of the Hu Line was significantly higher than that west of the Hu Line. The average PER was the highest in Beijing-Tianjin-Hebei (4.09) and lowest in the Northern Tianshan Mountains (0.71). The analysis of air pollution patterns and exposure risks in China and urban agglomerations in this study could provide scientific guidance for cities seeking to alleviate air pollution and prevent residents’ exposure risks.

Lagrangian Analysis of Moisture Sources of Precipitation in the Tianshan Mountains, Central Asia

AbstractThe moisture sources of precipitation in the Tianshan Mountains, one of the regions with the highest precipitation in Central Asia during 1979–2017 are comprehensively and quantitatively summarized by using a Lagrangian moisture source detection technique. Continental sources provide about 93.2% of the moisture for precipitation in the Tianshan Mountain, while moisture directly from the ocean is very limited, averaging only 6.8%. Central Asia plays a dominant role in providing moisture for all sub‐regions of the Tianshan Mountains. For the Western Tianshan, moisture from April to October comes mainly from Central Asia (41.4%), while moisture from November to March is derived primarily from Western Asia (45.7%). Nearly 13.0% of moisture to precipitation for Eastern Tianshan in summer originates from East and South Asia, and the Siberia region. There is a significant decreasing trend in the moisture contribution of local evaporation and Central Asia in the Eastern Tianshan during winter. The contribution of moisture from Europe to summer precipitation in the Central and Eastern Tianshan and the contribution of the North Atlantic Ocean to summer precipitation in the Northern, Central, and Eastern Tianshan also exhibit a decreasing trend. The largest increase in moisture in Western Tianshan stems from West Asia during extreme winter precipitation months. Europe is also an important contributor to extreme precipitation in the Northern Tianshan. The moisture from East and South Asia and Siberia during extreme precipitation months in both winter and summer is significantly enhanced in the Eastern Tianshan.

Influence of different irrigation methods on the alfalfa rhizosphere soil fungal communities in an arid region.

Xinjiang is the largest arid and saline agricultural region in China. The common irrigation methods in this area are traditional flood irrigation and drip irrigation. In this study, we investigated the effects of these two irrigation methods on the fungal diversity, community structures, and functions in alfalfa rhizosphere soil as well as the associated environmental factors in northern Tianshan Mountain (Xinjiang, China). Soil enzyme activities (urease and neutral phosphatase) were significantly higher in the drip-irrigated alfalfa rhizosphere soil than in the flood-irrigated alfalfa rhizosphere soil, whereas the fungal alpha diversity in the drip-irrigated alfalfa rhizosphere soil was significantly lower than that in the flood-irrigated alfalfa rhizosphere soil. Six dominant fungal phyla were identified (>0.1%), with Ascomycota being the most abundant in all soils, followed by Basidiomycota (5.47%), Mortierellomycota (1.07%), Glomeromycota (0.55%), Rozellomycota (0.27%), and Chytridiomycota (0.14%). Ascomycota and Glomeromycota species were significantly less abundant in drip-irrigated alfalfa rhizosphere soil than in flood-irrigated alfalfa rhizosphere soil. A LEFSe analysis identified Cladosporiaceae (20.8%) species as the most abundant marker fungi in drip-irrigated alfalfa rhizosphere soil. Of the 13 fungal functional groups identified on the basis of the functional annotation using the FUNGuild database, Ectomycorrhizal (22.29%) was the primary functional group. Compared with flood irrigation, drip irrigation significantly decreased the relative abundance of Ectomycorrhizal and Arbuscular_Mycorrhizal, while increasing the relative abundance of Plant_Pathogen, although not significantly (P = 0.19). Available potassium was revealed to be the main environmental factor influencing soil enzyme activities, fungal alpha diversity, fungal community structures, and fungal functions in response to the different irrigation methods. In conclusion, drip irrigation may be more appropriate than flood irrigation in the Tianshan dryland agricultural area for enhancing soil enzyme activities, but it may also increase the abundance of plant pathogenic fungi in the soil.

Effects and contributions of meteorological drought on agricultural drought under different climatic zones and vegetation types in Northwest China

Meteorological drought is one of the driving forces behind agricultural drought. The response of agricultural drought to meteorological drought remains poorly understood under different climatic zones and vegetation types in Northwest China (NWC). Furthermore, the contribution of climate factors and human activities to agricultural drought in NWC remains unclear. We combined the Standardized Precipitation Evapotranspiration Index (SPEI) and the satellite Vegetation Condition Index (VCI) to characterize meteorological and agricultural drought, respectively. Based on the trend analysis, Spearman's correlation coefficient and residual trend analysis, we studied the variation characteristics and response relationships of meteorological and agricultural drought under different climatic zones and vegetation types in NWC from 2000 to 2019 and evaluated the contributions of climate factors (SPEI and precipitation) and human activities on the agricultural drought. The results showed that under different climatic zones and vegetation types, the SPEI and VCI all showed an upward trend in NWC, indicating that meteorological and agricultural drought slowed down. It was further pointed out that the climate was humidified and the soil moisture increased in NWC. Meteorological drought has a definite effect on agricultural drought, and the effect varied non-linearly along the drought gradient with the strongest responses in the semiarid ecosystems. Drought resistance of different climatic zones and vegetation types was different, caused by the specific sensitivity and uniqueness of local arid environment. Among them, grasslands dominated the regional SPEI–VCI changes in NWC. The combined effects of climatic factors (SPEI and precipitation) and human activities promoted the variation of agricultural drought in NWC. Climatic factors were the main drivers of agricultural drought change in grasslands, with the contribution rate reaching 76.71%. However, human activities all contributed significantly to agricultural drought than climatic factors, especially in the Loess Plateau, Junggar Basin and northern Tianshan Mountains, where the positive contribution of human activities exceeded 80%. Thus, the SPEI and VCI can effectively reveal the change law of meteorological drought and agricultural drought in NWC. This study provides a theoretical basis for drought disaster relationship assessment.

天山北麓典型水库细菌多样性分析

PDF HTML阅读 XML下载 导出引用 引用提醒 天山北麓典型水库细菌多样性分析 DOI: 10.5846/stxb202009082345 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（41761096） Diversity of the bacterial community in reservoirs in the north part of Tianshan Mountain Author: Affiliation: Fund Project: Supported by the National Natural Science Foundation of China(41761096) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了探讨天山北麓中段水库细菌的多样性及其功能，选取蘑菇湖水库（MGW）、奎屯/车排子水库（KCW）、安集海水库（AJW）和八一水库（BYW）为典型水库进行宏基因组学分析。多点采集水库水样，收集水样中的微生物，CTAB法提取总DNA，用细菌16S rDNA通用引物扩增V3-V4区，扩增产物进行高通量测序，使用BLAST、USEARCH、QIIME等软件和在线工具分析水库细菌的多样性，使用PICRUSt软件和KEGG数据库预测细菌功能基因组成。结果表明，水库细菌分属18个门、38个纲和181个属，其中AJW的操作分类单元（Operational taxonomic units，OTUs）数量和多样性指数较高。4个水库菌群组成有一定的共性，在门分类阶元上优势菌为变形菌门（Proteobacteria）和拟杆菌门（Bacteroidetes）；在纲分类阶元上优势菌为黄杆菌纲（Flavobacteriia）；在属分类阶元上优势菌为黄杆菌属（Flavobacterium）。然而各水库菌群组成也存在较大差异，在变形菌门中，γ-变形菌纲（Gammaproteobacteria）的相对丰度在MGW和BYW较高，α-变形菌纲（Alphaproteobacterial）和β-变形菌纲（Betaproteobacteria）分别于AJW和KCW具有较高丰度；芽孢杆菌纲（Bacilli）在AJW和MGW具有较高丰度；相对丰度较高的菌属还包括AJW的动性杆菌属（Planomicrobium）、KCW的马赛菌属（Massilia）、MGW的不动杆菌属（Acinetobacter）和动性杆菌属以及BYW的假单胞菌属（Pseudomonas）和嗜冷杆菌属（Psychrobacter）；另外，AJW特有多种丰度较高的菌纲和菌属，其中微小杆菌属（Exiguobacterium）和CL500-29_marine_group均有利于水质和菌群多样性的维持。PICRUSt功能预测分析表明，4个水库菌群的多种代谢以及遗传信息处理、信号传递和细胞生长相关功能基因丰度较高，并含有环境异生物降解代谢相关基因，其中苯甲酸、氨基苯甲酸酯、氯烷烃和氯烯烃以及萘降解相关基因的相对丰度较高。以上结果提示，天山北麓中段不同水库菌群组成存在差异，其与水源、周边环境和人类活动等因素相关。水库菌群含有芳香族和有机氯等化合物降解相关基因，其可在污染物的降解和生物修复中发挥作用。 Abstract:To examine the diversity and function of the bacterial community in the reservoirs at the middle part of Northern Tianshan Mountain, Moguhu reservoirs (MGW), Kuitun/Chepaizi reservoirs (KCW), Anjihai reservoirs (AJW), and Bayi reservoirs (BYW) were selected as the typical reservoirs for metagenomics analysis. The surface water samples of the reservoirs were collected at multiple points, the bacteria in the water samples were collected by centrifugation. The bacterial DNAs were extracted by CTAB method, the V3-V4 regions were amplified with bacterial 16S rDNA universal primer followed by high-throughput sequencing. The software and online tools including BLAST, USEARCH and QIIME were used to analyze the bacterial diversity, and the functional gene compositions were predicted using PICRUSt software and KEGG database. The results showed that the bacteria from the four reservoirs belonged to 18 phyla, 38 classes and 181 genera, the operational taxonomic units (OTUs) number and diversity index of AJW was higher. There was something in common in the bacterial community compositions of the four reservoirs. The Proteobacteria and Bacteroidetes were the dominant bacteria at the phylum level, Flavobacteria was the dominant bacteria at the class level, and Flavobacterium was the dominant bacteria at the genus level. However, there were great differences in the bacterial community compositions of the four reservoirs. In Proteobacteria, Gammaproteobacteria showed a higher relative abundance in MGW and BYW, and Alphaproteobacterial and Betaproteobacteria showed a higher relative abundance in AJW and KCW, respectively; Bacillus exhibited a higher relative abundance in AJW and MGW; other bacteria with higher abundance included Planomicrobium in AJW, Massilia in KCW, Acinetobacter and Planomicrobium in MGW, and Pseudomonas and Psychrobacter in BYW; in addition, some specific high-abundance classes and genera were found in AJW, among them, both Exiguobacterium and CL500-29_marine_group were conducive to maintaining the water quality and bacterial diversity. PICRUSt function prediction analysis indicated that the genes of the bacterial community in four reservoirs related to metabolism, genetic information processing, environmental information processing and cellular processes showed relatively a high abundance. In addition, some bacterial genes were related to the biodegradation of xenobiotic compounds, and the relative abundances of genes related to degradation of benzoate, aminobenzoate, chloroalkane and chloroalkene, and naphthalene were higher. In summary, the compositions of the bacterial community in different reservoirs were varied, which could be related to the water source, surrounding environment, and human activities. The presence of the genes related to the degradation of aromatic compounds and organochlorine compounds in the reservoirs could play a potential role in pollutant degradation and bioremediation. 参考文献 相似文献 引证文献

Novel reassortment 2.3.4.4b H5N8 highly pathogenic avian influenza viruses circulating in Xinjiang, China

In 2016, H5N8 avian influenza viruses of clade 2.3.4.4b were detected at Qinghai Lake, China. Afterwards, the viruses of this clade rapidly spread to Asia, Europe, and Africa via migratory birds, and caused massive deaths in poultry and wild birds globally. In this study, four H5N8 isolates (abbreviated as 001, 002, 003, and 004) were isolated from the live poultry market in Xinjiang in 2017. Phylogenetic analysis showed that the hemagglutinin genes of the four isolates belonged to clade 2.3.4.4b, while the viral gene segments were from multiple geographic origins. For 002, the polymerase acidic gene had the highest sequence homology (99.55 %) with H5N8 virus identified from green-winged teal in Egypt in 2016, and the remaining genes exhibited the highest sequence homologies (99.18–100 %) with those of H5N8 viruses isolated from domestic duck sampled in Siberia in 2016. The polymerase basic 1 gene clustered together with H5N8 virus identified from painted stork of India in 2016, and the remaining genes had relatively close genetic relationships with H5N8 viruses identified from the duck of Siberia in 2016 and turkey in Italy in 2017. For the other three isolates, the nucleoprotein gene of 001 had the highest sequence homology (98.82 %) and relatively close genetic relationship with H9N2 viruses identified from poultry in Vietnam and Cambodia in 2015–2017, and all the remaining genes had the highest sequence homologies (99.18 %–99.58 %) and relatively close genetic relationships with H5N8 viruses identified from poultry and waterfowl sampled in African countries in 2017 and swan sampled in China in 2016. Multiple basic amino acids were observed at cleavage sites in the hemagglutinin proteins of the H5N8 isolates, indicating high pathogenicity. In addition, the L89V, G309D, R477G, I495V, A676T and I504V mutations in the polymerase basic 2 protein, N30D and T215A mutations in the matrix 1 protein, P42S mutation, and 80−84 amino acid deletion in the nonstructural 1 protein were detected in all isolates. These mutations were associated with increased virulence and polymerase activity in mammals. Therefore, our results indicate that the H5N8 isolates involved multiple introductions of reassorted viruses, and also revealed that the wetlands of Northern Tianshan Mountain may play a key role in H5N8 AIVs disseminating among Central China, the Eurasian continent, and East African Countries.

Dynamics of Vegetation Greenness and Its Response to Climate Change in Xinjiang over the Past Two Decades

Climate change has proven to have a profound impact on the growth of vegetation from various points of view. Understanding how vegetation changes and its response to climatic shift is of vital importance for describing their mutual relationships and projecting future land–climate interactions. Arid areas are considered to be regions that respond most strongly to climate change. Xinjiang, as a typical dryland in China, has received great attention lately for its unique ecological environment. However, comprehensive studies examining vegetation change and its driving factors across Xinjiang are rare. Here, we used the remote sensing datasets (MOD13A2 and TerraClimate) and data of meteorological stations to investigate the trends in the dynamic change in the Normalized Difference Vegetation Index (NDVI) and its response to climate change from 2000 to 2019 across Xinjiang based on the Google Earth platform. We found that the increment rates of growth-season mean and maximum NDVI were 0.0011 per year and 0.0013 per year, respectively, by averaging all of the pixels from the region. The results also showed that, compared with other land use types, cropland had the fastest greening rate, which was mainly distributed among the northern Tianshan Mountains and Southern Junggar Basin and the northern margin of the Tarim Basin. The vegetation browning areas primarily spread over the Ili River Valley where most grasslands were distributed. Moreover, there was a trend of warming and wetting across Xinjiang over the past 20 years; this was determined by analyzing the climate data. Through correlation analysis, we found that the contribution of precipitation to NDVI (R2 = 0.48) was greater than that of temperature to NDVI (R2 = 0.42) throughout Xinjiang. The Standardized Precipitation and Evapotranspiration Index (SPEI) was also computed to better investigate the correlation between climate change and vegetation growth in arid areas. Our results could improve the local management of dryland ecosystems and provide insights into the complex interaction between vegetation and climate change.

The constraint of deep rock stresses in H underground gas storage based on a modified stress polygon and focal mechanism solution

H underground gas storage (H-UGS), located in the junction of the southern margin of the Junggar Basin and the eastern part of the northern Tianshan Mountains, is one of the large natural gas storage in China. It is of significance to study the deep rock stresses in H-UGS for fault slip tendency, safe storage of energy and other research. Most of the regional stress information in H-UGS data from in-suit measurements lacks deep in-suit stress data in this region. This research proposes a hybrid constrain stress magnitudes present in deep rock masses. First, the fault friction strength, an essential parameter of lateral pressure coefficient polygon, is established by the stress accumulation index method and apparent friction strength evaluation method. Second, we inverse the stress factor R from the focal mechanism solutions in this area, and the lateral pressure coefficient polygon is qualified quadratic to narrow down the range of results by this parameter. Finally, the complete stress profile of H-UGS is obtained by using the simple transition relationship between lateral pressure coefficient and in-situ stress. The result shows that the principal compressive stress of the H-UGS region is determined by the N22°E, the maximum lateral pressure coefficient K max (or S H) at three depths (3.0km, 6.5km, and 12.0km ) are 1.2 (80.22 MPa), 1.22 (202.72 MPa), 1.28 (421.34 MPa) respectively, and the minimum lateral pressure coefficient K min (or S h) are 0.87 (58.21 MPa), 0.86 (142.12 MPa), 0.86 (282.61 MPa) respectively. The result is primarily consistent with in-situ measurement from the depth of 3.0km to 3.7km. The maximum horizontal principal stress and the minimum coincidence ratio are 54% and 69%. The result of estimating deep rock stresses established in this research provides sufficient regional stress field data in H-UGS.

Paleo-environmental implications of the micro-botanical remains recovered from a military garrison of Han Dynasty in Xinjiang

According to the dynastic chronicles of the Han dynasty, City of Shule (疏勒城) was a large fortress located at in the farthest northwest of the Han Empire. The Shichengzi site was a settlement occupied by Han armies, which was considered as matching the location of City of Shule on the ancient Silk Road in Xinjiang, directly dating to about the first century AD. In the present study, we provide a preliminary investigation on palaeobotanical and palynological evidence recovered from a depositing soil profile at Shichengzi site in northern Tianshan Mountains. Although it shows that natural vegetations around Shichengzi was dominated by desert steppe during the late Holocene period, it can be seen that there was a relatively warm and humid environment when Han armies firstly relocated in the region. This suggests that such an improved climate conditions might have played an important role in supporting the development of Han culture in eastern Central Asia at approximately 2000 BP.

Evaluation on the Change Characteristics of Ecosystem Service Function in the Northern Xinjiang Based on Land Use Change

Monitoring the interannual changes in land use and the temporal and spatial characteristics of the ecosystem services value (ESV) can help to comprehensively and objectively understand the distribution of regional ecological patterns. The mountain–oasis–desert transition zone in the northern Tianshan Mountain region of Xinjiang, China, is a geographically unique area with a highly sensitive ecosystem. As a data source, the study uses Landsat TM images from 1990, 2000, 2010, and 2018 along with GIS-extracted data to calculate the dynamic degree of land use. As well, the spatial and temporal patterns of land use change and ESV are quantitatively analyzed by using the equivalent factor method, sensitivity index, and spatial correlation studies. The results reveal the following: (1) From 1990 to 2018, the land use changes in the northern Tianshans are relatively drastic, mainly due to the increase in cultivated land, grassland and construction land, and the decrease in forest land, water, and unused land. (2) The ESV increases and then decreases, for a total loss of about 271.63 × 108 yuan. The largest decrease is in forest value, and the largest increase (around 129.94%) is in construction land. (3) The spatial distribution pattern of ESV in the northern Tianshans is apparent, showing high in the north and southwest, and low in the central and southeast portions of the study area. Additionally, there is a visible spatial correlation and aggregation in ESV. The present research can provide theoretical support for the environmental protection of the ecologically vulnerable area of the northern Tianshans as well as for further construction across the region.

2021–2025 is a period of great development of China's natural gas industry: Suggestions on the exploration and development of natural gas during the 14th five-year plan in China

Among the world's 10 major gas producing countries, only the United States (USA), Russia and Iran have annual gas production of 250 × 109 m3 or more. China is expected to have gas output of 250 × 109 m3 in 2025. There are three advantages for the great development of natural gas industry in China. Firstly, the natural gas resources are rich and the proved rate is low and only 8.6%, so it has the resource advantage for faster development; Secondly, over the past 35 years, natural gas production continues to grow, with the growth advantage for faster development; Finally, since 2006, the remaining recoverable reserves of natural gas have been increasing year by year, showing the reserve advantage for faster development. In recent 10 years, China's annual natural gas production growth rate, remaining recoverable reserves and reserve-production ratio of natural gas support that China's annual gas production in 2025 will reach 250 × 109 m3. Suggestions for accelerating natural gas exploration and development during the 14th Five-Year Plan Period: (1) Opening new exploration and development fields of Carboniferous-Permian shale gas in the Ordos Basin; (2) Exploring three potential large gas districts with hidden coal measures in the northern Tianshan Piedown Depression, Qaidam Depression, and Xihu Sag; (3) Accelerating the development of seven large gas fields with proved reserves over 100 × 109 m3, such as Lingshui 17–2 Gas Field; (4) Increasing the drilling of gas wells and ultra-deep exploration wells.

Quantifying the contribution of climate change and human activities to biophysical parameters in an arid region

Quantifying the variation of biophysical parameters and their driving mechanisms is essential for monitoring land surface environmental changes and for understanding the land–atmosphere interaction in the arid region. Due to the complexity of human activities, most researches are limited to climate change, whereas the response analysis of human activities to changes in biophysical parameters are still lacking or not comprehensively considered. Therefore, large biases and uncertainties still exist in the estimates of regional responses to global change. Firstly, we specifically quantified the main human activities related to land use/land cover change (LULCC) in the northern Tianshan Mountains (NTM), and identified the spatiotemporal changes of primary biophysical parameters, including Albedo, leaf area index (LAI), land surface temperature (LST), and Normalized Difference Vegetation Index (NDVI). Then, we tested the performance of the five models used, including multiple linear regression (MLR), random forest (RF), support vector regression (SVR), multi-layer perceptron (MLP), and K-nearest neighbor (KNN). RF outperformed others and was used to quantify and disaggregate the contribution of climate change and human activities to land surface parameters in the NTM. We found a strong spatial heterogeneity in the spatial variation of all biophysical parameters. Except for LST, the annual maximum Albedo, LAI, and NDVI showed a significant increasing trend in the NTM from 2000 to 2019 (p < 0.05). Generally, climate change contributed more to the biophysical parameters than human activities. However, the contribution of human activities to NDVI was 0.51, which was greater than that of climate change during 2000–2015. This study provides new insight on the impact of climate change and human activities on biophysical parameters and a scientific basis for model parameterization in the arid region.

Estimation of mountain block recharge on the northern Tianshan Mountains using numerical modeling

Estimation of mountain block recharge on the northern Tianshan Mountains using numerical modeling

Spatiotemporal investigation of the interactive coercing relationship between urbanization and ecosystem services in arid northwestern China

AbstractRapid urbanization has negative effects on ecosystem structure, function, and balance, leading to the loss of ecosystem services (ES) and posing a threat to regional sustainable development. However, the complex interactive coercing relationship between urbanization and ES is not yet fully understood, especially in arid Northwestern China. In this study, we constructed an evaluative framework for urbanization and ES using land cover/land use data and socioeconomic data from 1990 to 2018. We used global and local autocorrelation models to reveal the spatiotemporal interaction between urbanization and ES. The results revealed that the urbanization index increased from 0.06 in 1990 to 0.16 in 2018 in Xinjiang, and urbanization was significantly negatively correlated with ES. With the acceleration of urbanization, the ecosystem services value (ESV) has decreased 2,698.74 × 109 Yuan from 1990 to 2018 (6.62 Yuan = 1 .00 US$). Due to geographical advantages, resource conditions, and land use changes, the spatial relationship of urbanization and ES has obvious heterogeneity. High–low correlation areas are mainly concentrated in the Northern Tianshan Mountain Economic Zone, whereas low–high correlation areas are concentrated in the Kashgar and Hotan Oases in southern Xinjiang. Based on regional geographical conditions and the spatial heterogeneity of resources, diversified ecological, social, and economic balance models should be considered to promote future sustainable urban planning and development.

Molecular systematics of the Sicista tianschanica species complex: a contribution from historical DNA analysis.

The Tianshan birch mouse Sicista tianschanica is an endemic of the Central Asian mountains and has previously been shown to include several karyomorphs (“Terskey”, “Talgar”, “Dzungar”); however, the taxonomic status of these forms has remained uncertain. We examined the genetic variation in S. tianschanica based on historical DNA samples from museum collections, including the type series. Mitochondrial and nuclear data indicated that the species complex includes two major clades: Northern (N) and Southern (S) (cytb distance 13%). The N clade corresponds to the “Dzungar” karyomorph (Dzungar Alatau, Tarbagatay). The S clade is comprised of four lineages (S1–S4) divergent at 6–8%; the relationships among which are resolved incompletely. The S1 lineage is found in eastern Tianshan and corresponds to the nominal taxon. The S2 is distributed in central and northern Tianshan and corresponds to the “Terskey” karyomorph. The S3 is restricted to Trans-Ili Alatau and belongs to the “Talgar” karyomorph. The S4 is represented by a single specimen from southeastern Dzungar Alatau with "Talgar" karyotype. No interlineage gene flow was revealed. The validity of S. zhetysuica (equivalent to the N clade) is supported. Based on genetic and karyotypic evidence, lineages S2 and S3 are described as distinct species. The status of the S4 requires further investigation.

Early Neoproterozoic (~920 Ma) Granite–Gneiss of the Junggar Alataw, South Kazakhstan: Age Substantiation Based on the Results of U–Th–Pb (SIMS) Dating

Based on the results of U–Th–Pb (SIMS) dating, an Early Neoproterozoic (924 ± 4 Ma) age was obtained for granite–gneiss of the Sarychabyn Complex, which is one of the oldest complexes in the Junggar Alataw Range. This value constrains the minimum age of the metasedimentary rocks of the Sarychabyn Group hosting granite–gneiss as well. The most likely age of metasediments is Late Mesoproterozoic–Early Neoproterozoic, which is consistent with the age of lithologically similar complexes in the adjacent regions of Kazakhstan and China. The age of the gneiss of the Sarychabyn Complex coincides with the ages of anorogenic granitoids and felsic volcanic rocks from the Aktau-Mointy massif of Central Kazakhstan and the ages of granitoids in the Wenquan Complex in China. An episode of granitoid magmatism at ~920 Ma, widespread in the Aktau-Junggar microcontinent, is a characteristic feature that distinguishes it from other Precambrian crustal blocks of Kazakhstan and the Northern Tianshan.