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Geomorphological Evolution Revealed by Aeolian Sedimentary Structure in Badain Jaran Desert on Alxa Plateau, Northwest China

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Chinese Geographical Science 2011年第3期21卷 267-278页

作者： BAI Yang WANG Nai'ang LIAO Kongtai Patrick KLENK College of Earth and environmental Sciences Center for Hydrologic Cycle and Water Resources in Arid Region Lanzhou University Lanzhou 730000 China Forestry Scientific Technology Popularization Master station Gansu Province Lanzhou 730046 China Institute of environmental Physics INF 229 University of Heidelberg 69120 Heidelberg Germany

The Badain Jaran Desert,located in the Alxa Plateau,Northwest China,features mega-dunes and a unique dune-lake alternation *** paper presented the aeolian sediment structures of three representative dunes in the Badain Jaran Desert using ground-penetrating radar (GPR).We processed and analyzed the GPR data and investigated the feasibility of using integrated GPR and sedimentological data to reconstruct dunes structure,sedimentary environment and geomorphological *** results show that the internal structures of star dune and transverse dune represent various stages of mega-dune evolution: the main deposition processes of mega-dune are similar to those of transverse dunes but have a more complicated mechanism of sand transport and deposition because of the superimposition of dunes;the upper section of the mega-dune has a structure similar to that of star dune,with vertical aggradations on *** hyperbolae in the GPR profile indicates that the presence of ancient dunes characterized by calcareous cementation layers is involved in the maintenance of mega-dunes,and water levels,shown by continuous,sub-horizontal GPR reflections,are supposed to be closely related to mega-dunes and the interdune *** of wet sand and horizontal stratifications on the GPR image indicate moisture potentials with different levels inside *** multiplex geomorphology in the Badain Jaran Desert is the result of global climatic undulation,the unique geographical location,the geological structural features,etc.

关键词： Badain Jaran Desert Ground-Penetrating Radar (GPR) mega-dunes sedimentary structure geomor- phological evolution

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Identifying human-induced influence on microbial community:A comparative study in the effluent-receiving areas in Hangzhou Bay

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Frontiers of environmental Science & Engineering 2019年第6期13卷 103-113页

作者： Yuhan Zheng Zhiguo Su Tianjiao Dai Feifei Li Bei Huang Qinglin Mu Chuanping Feng Donghui Wen School of Water Resource and environmental Science China University of Geosciences(Beijing)Beijing 100083China College of environmental Sciences and Engineering Peking UniversityBeijing 100871China Zhejiang Provincial Zhoushan Marine Ecological environmental monitoring station Zhoushan 316021China

Microbial community structure is afiected by both natural processes and human *** coastal area,anthropegenetic activity can usually lead to the discharge of the effluent from wastewater treatment plant(WWTP)to sea,and thus the water quality chronically turns worse and marine ecosystem becomes *** play key roles in pollutants degradation and ecological restoration;however,there are few studies about how the WWTP effluent disposal influences coastal microbial *** this study,sediment samples were collected from two WWTP effluentreceiving areas(abbreviated as JX and SY)in Hangzhou ***,based on the high-throughput sequencing of 16S rRNA gene,microbial community structure was ***,several statistical analyses were conducted to reveal the microbial community characteristics in response to the effluent *** PCoA,the significant difference of in microbial community structure was determined between JX and SY;using RDA,water COD and temperature,and sediment available phosphate and ammonia nitrogen were identified as the key environmental factors for the community difference;using LDA effect size analysis,the most distinctive microbes were found and their correlations with environmental factors were investigated;and according to detrended beta-nearesttaxon-index,the sediment microbial communities were found to follow"niche theory".An interesting and important finding was that in SY that received more and toxic COD,many distinctive microbes were related to the groups that were capable of degrading toxic organic *** study provides a clear illustration of eco-environmental deterioration under the long-term human pressure from the view of microbial ecology.

关键词： Microbial community structure Effluent-receiving area High-throughput sequencing Costal sediments Wastewater treatment plant(WWTP)

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Nitrous Oxide Emissions from a Masson Pine Forest Soil in Subtropical Central China

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Pedosphere 2015年第2期25卷 263-274页

作者： CHEN Dan FU Xiao-Qing WANG Cong LIU Xin-Liang LI Hang SHEN Jian-Lin WANG Yi LI Yong WU Jin-Shui Changsha Research station for Agricultural and environmental monitoring Key Laboratory of Agro-ecological Processes in Subtropical RegionInstitute of Subtropical AgricultureChinese Academy of Sciences

The forest ecosystem plays a pivotal role in contributing greenhouse gases to the *** order to characterize the temporal pattern of nitrous oxide(N_2O) emissions and identify the key factors affecting N_2O emissions from a Masson pine forest in a hilly red-soil region in subtropical central China,we measured the N_2O emissions in Jinjing of Hunan Province using the static chambergas chromatographic method for 3 years(2010-2012) and analyzed the relationships between the N_2O fluxes and the environmental *** results revealed that the N_2O fluxes over the 3 years varied from-36.0 to 296.7 μg N m^(-2) h^(-1),averaging 18.4±5.6 μg N m^(-2) h^(-1)(n=3).The average annual N_2O emissions were estimated to be 1.6±0.3 kg N ha^(-1) year^(-1).The N_2O fluxes exhibited clear intra-annual(seasonal) variations as they were higher in summers and lower in *** with other forest observations in the subtropics,N_2O emissions at our site were relatively high,possibly due to the high local dry/wet N deposition,and were mostly sensitive to variations in precipitation and soil ammonium N *** this work,a multiple linear regression model was developed to determine the influence of environmental factors on N_2O emissions,in which a category predictor of "Season" was intentionally used to account for the seasonal variation of the N_2O *** a model explained almost 40%of the total variation in daily N_2O emissions from the Masson pine forest soil studied(P<0.001).

关键词： environmental factors multiple linear regression model N deposition season subtropical forests

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Patterns of shrub species richness and abundance in relation to environmental factors on the Alxa Plateau:Prerequisites for conserving shrub diversity in extreme arid desert regions

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Science China Earth Sciences 2009年第5期52卷 669-680页

作者： XinRong Li HuiJuan Tan MingZhu He XinPing Wang XiaoJun Li Shapotou Desert Research and Experiment station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Shrub species are considered the dominant plants in arid desert ecosystems, unlike in semiarid steppe zones or in grassland ecosystems. On the Alxa Plateau, northern China, sparse vegetation with cover ranging from 15... 详细信息

关键词： biodiversity conservation shrub species richness abundance Alxa Plateau desert ecosystems

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Ecological adaptation strategies of annual plants in artificial vegetation-stabilized sand dune in Shapotou Region

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Science China Earth Sciences 2004年第Z1期47卷 50-60页

作者： ZHANG Jingguang LI Xinrong WANG Xinping WANG Gang Shapotou Desert Experimental Research station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Taking annual plant Eragrostis poaeides in the artificial vegetation-stabilized sand dune in the Shapotou Experimental Research station as example, study has been done on the adaptation strategies of annual plants to random environment through fixed quadrat observations of population changes and fixed plant determinations of individual growth, seed germination,population dynamics, spatial distribution pattern of population, competition and regulation. During the growing season, the survival rate of annual plants depends on the precipitation intensity and precipitation duration which activate the germination of seeds. The optimal germination strategy of annual plants in this habitat during the growing season appears as continuous germination under suitable conditions. Such continuous germination is an adaptive characteristic of annual plants to random environment. In addition, the variation processes of population size and regulation mechanism of E. poaeoides are studied. Statistical results of natural population in four consecutive years show that water condition in the habitat is the leading factor affecting the population dynamics of E. poaeoides. During the establishment period E. poaeoides had a higher death rate, but in the middle to later period they could survive stably. Due to the limitation of soil moisture, the competition among individuals for water inevitably led to self-thinning phenomena. Under very arid condition, the survival curve of annual herbs entirely appears as Deevey Ⅲ type (C type), but under relatively adequate precipitation condition, the survival curve appears as intermediate type. The strategy of life history obviously appears as r-strategy. Plant species of r-strategy often occurs in the early succession stage of the communities. In the relatively adequate and evenly-distributed rainfall years, E. poaeoides population exhibited a density-dependent, i. e., survival rate increased with decrease in population density. The main pattern to re

关键词： Shapotou region Eragrostis poaeoides ecological adaptation strategy.

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Influence of variation of soil spatial heterogeneity on vegetation restoration

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Science China Earth Sciences 2005年第11期48卷 2020-2031页

作者： LI Xinrong Shapotou Desert Experiment and Research station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Numerous hypotheses and conceptional models dealing with the grassland deserti-fication or degradation processes recognize that the invasion of shrubs in grasslands is the most striking feature of the variation of vegetation patterns in the grassland degradation or desertifica-tion processes in arid and semiarid regions. This is because the invasion of shrubs in grasslands increases the heterogeneity of the temporal and spatial distribution of primary vegetation and soil resources. As a result, the biological processes of the soil-vegetation system are increasingly concentrated in the “fertile islands” under shrub canopies, and the soil between shrubs gradually turns into bare area or moving sand under the influences of prolonged wind and water erosion. Most of relative researches support this bio-ecological interpretation for the degraded process of grassland. However, as viewed from the other aspect, the shrub vegetation distributed in patches also serves as the “trigger spots” for the grassland restoration or desertification reversion, and this has been demonstrated by the practices of combating desertification in China. Nearly 50 years of succession of artificial sand-binding vegetation in the Shapotou area and the regional restoration of eco-environment are the theoretical verification and successful example for the desertification reversion. The establishment of artificial vegetation in the region began with the installation of sand fences and planting xerophytic shrubs relying on less than 200 mm of annual precipitation under the non-irrigation condition, this made the moving sand, an originally uni-formly distributed soil resource, occur the variation of spatial heterogeneity. Through the redis-tribution of precipitation and dustfall by the canopy of xerophytic shrubs, litter accumulation and cryptogamic crust development, soil-forming processes under shrub canopies were accelerated; in the meantime, it also created a favorable condition for the invasion and

关键词： Tengger Desert, sand-binding vegetation, soil heterogeneity, succession, eco-restoration

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Soil water and salt distribution under furrow irrigation of saline water with plastic mulch on ridge

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Journal of Arid Land 2013年第1期5卷 60-70页

作者： LiJuan CHEN Qi FENG Alxa Desert Ecohydrological Experimental Research station Cold and Arid Regions Environmental and Engineering ResearchInstitute Chinese Academy of Sciences Lanzhou 730000 China

Furrow irrigation when combined with plastic mulch on ridge is one of the current uppermost wa- ter-saving irrigation technologies for arid regions. The present paper studies the dynamics of soil water-salt trans- portation and its spatial distribution characteristics under irrigation with saline water in a maize field experiment. The mathematical relationships for soil salinity, irrigation amount and water salinity are also established to evaluate the contribution of the irrigation amount and the salinity of saline water to soil salt accumulation. The result showed that irrigation with water of high salinity could effectively increase soil water content, but the increment is limited com- paring with the influence from irrigation amount. The soil water content in furrows was higher than that in ridges at the same soil layers, with increments of 12.87% and 13.70% for MMF9 （the treatment with the highest water salinity and the largest amount of irrigation water） and MMF1 （the treatment with the lowest water salinity and the least amount of irrigation water） on 27 June, respectively. The increment for MMF9 was gradually reduced while that for MMF1 increased along with growth stages, the values for 17 August being 2.40% and 19.92%, respectively. Soil water content in the ridge for MMF9 reduced gradually from the surface layer to deeper layers while the surface soil water content for MMF1 was smaller than the contents below 20 cm at the early growing stage. Soil salinities for the treatments with the same amount of irrigation water but different water salinity increased with the water salinity. When water salinity was 6.04 dS/m, the less water resulted in more salt accumulation in topsoil and less in deep layers. When water salinity was 2.89 dS/m, however, the less water resulted in less salt accumulation in topsoil and salinity remained basically stable in deep layers. The salt accumulation in the ridge surface was much smaller than that in the furrow bottom under this

关键词： water and salt transportation furrow irrigation saline water soil salinity soil water content

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A pulsed switching peroxi-coagulation process to control hydroxyl radical production and to enhance 2,4-Dichlorophenoxyacetic acid degradation

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Frontiers of environmental Science & Engineering 2018年第5期12卷 86-90页

作者： Yaobin Lu Songli He Dantong Wang Siyuan Luo Aiping Liu Haiping Luo Guangli Liu Renduo Zhang Guangdong Provincial Key Laboratory of environmental Pollution Control and Remediation Technology School of Environmental Science and EngineeringSun Yat-sen UniversityGuangzhou 510006China Zhaoqing environmental monitoring station Zhaoqing Institute of Environmental ScienceZhaoqing 526040China Nanjing Institute of environmental Sciences Ministry of Environmental ProtectionNanjing 210042China

The aim of this study was to develop a new pulsed switching peroxi-coagulation system to control hydroxyl radical(∙OH)production and to enhance 2,4-Dichlorophenoxyacetic acid(2,4-D)*** system was constructed with a sacrifice iron anode,a Pt anode,and a gas diffusion *** of H_(2)O_(2) and Fe^(2+)was controlled separately by time delayers with different pulsed switching *** current densities of 5.0 mA/cm^(2)(H_(2)O_(2))and 0.5 mA/cm^(2)(Fe^(2+)),the∙OH production was optimized with the pulsed switching frequency of 1.0 s(H_(2)O_(2)):0.3 s(Fe^(2+))and the ratio of H_(2)O_(2) to Fe^(2+)molar concentrations of *** the optimal condition,2,4-D with an initial concentration of 500 mg/L was completely removed in the system within 240 *** energy consumption for the 2,4-D removal in the system was much lower than that in the electro-Fenton process(686 vs.13610 kWh/kg TOC).The iron consumption in the system was~20 times as low as that in the peroxi-coagulation process(19620 vs.3940400 mg/L)within 240 *** system should be a promising peroxi-coagulation method for organic pollutants removal in wastewater.

关键词： Pulsed switching peroxi-coagulation system Energy consumption Hydroxyl radical production 2,4-Dichlorophenoxyacetic acid

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Source apportionment and ecological risk assessment of PAHs in surface sediments from the Liaodong Bay,northern China

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Acta Oceanologica Sinica 2018年第4期37卷 12-21页

作者： ZHANG Yufeng WU Jinhao SONG Lun SONG Yonggang YANG Meng WANG Nianbin HAN Jiabo GUAN Daoming College of Chemistry and Chemical Engineering Ocean University of China Qingdao 266100 China Liaoning Ocean and Fisheries Science Research Institute Dalian 116023 China Liaoning Ocean Environment monitoring station Dalian 116023 China Dalian environmental monitoring Center Dalian 116023 China National Marine environmental monitoring Center Dalian 116023 China

The sources and ecological risk from sixteen polycyclic aromatic hydrocarbons in surface sediment in the Liaodong Bay were investigated from 2014 to *** total concentrations of PAHs ranged from 88.5 to 347.1 ng/g,and the high value occurred in the central region of the Liaodong *** analysis identified two site clusters representing the coastal region affected by land-based pollution and the central region of the Liaodong *** component analysis-multiple linear regression and diagnostic ratios suggested that PAHs contaminants originated from a mixture of combustion and petroleum sources,and the major was combustion *** on sediment quality guideline,naphthalene,acenaphthylene,acenaphthene,phenanthrene and dibenz[a,h]anthracene may occasionally cause adverse biological effects in some *** toxic equivalent concentrations of carcinogenic PAHs indicated low carcinogenic risk for the Liaodong *** ecological risk and toxic pollution levels of PAHs were higher in the central region than in the coastal region along the Liaodong Bay.

关键词： polycyclic aromatic hydrocarbons Liaodong Bay source apportionment ecological risk assessment,sediment

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QSPR Analysis of the Physicochemical Properties for Phthalic Acid Esters

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Chinese Journal of Structural Chemistry 2013年第12期32卷 1880-1884页

作者： XU Hui-Ying SHU Tian-Ge WANG Wei ZHU Jian-Qing LU Yin XU Xiao-Lu WU Gang College of Biology & Environment Engineering Zhejiang Shuren University Zhenhai environmental monitoring station Department of Basic Courses Zhejiang Shuren University Shaoxing University

Based on quantitative structure-property relationship （QSPR） of organic compounds, the molecular connectivity indices of 21 phthalic acid ester compounds were extracted. Relationship between the physicochemical properties （n-octanol/air partition coefficient, vapor pressure, water solubility） and the molecular connectivity indices of phthalic acid ester compounds have been established by multiple linear regression （MLR） method. The results showed that the zero-order valence connectivity index （0Xu） is the topology parameter which affects octanol/water partition coefficient and water solubility, and the topology parameter which affects vapor pressure is the first-order connectivity index （1X）. This indicated to a certain extent_that the molecular connectivity indices can be well used to express the quantitative relationship between the physicochemical properties and structure descriptions of phthalic acid ester compounds. The models constructed have good robustness and highly predictive capability.

关键词： phthalic acid esters molecular connectivity index,physicochemical property QSPR

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