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desert vegetation distribution and species-environment relationships in an oasis-desert ecotone of northwestern China

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Journal of Arid Land 2019年第3期11卷 461-476页

作者： ZHAO Peng QU Jianjun XU Xianying YU Qiushi JIANG Shengxiu ZHAO Heran Key Laboratory of desert and desertification Northwest Institute of Eco-environment and ResourcesChinese Academy of SciencesLanzhou 730000China State Key Laboratory Breeding Base of desertification and Aeolian Sand Disaster Combating Gansu Desert Control Research InstituteLanzhou 730070China Gansu Minqin National Field Observation and Research Station on Ecosystem of desertification Rangeland Minqin 733000China University of Chinese Academy of Sciences Beijing 100049China

Environmental heterogeneity significantly affects the structure of ecological *** vegetation distribution and its relationship with environmental factors is essential to understanding the abiotic mechanism(s)driving vegetation succession,especially in the ecologically fragile *** this study,based on the quantitative analysis of plant community and environmental factors in 68 plots at 10 different transects in the Minqin oasis-desert ecotone(ODE)of northwestern China,we investigated desert vegetation distribution and species-environment relationships using multivariate ***-way indicator species analysis(TWINSPAN),detrended correspondence analysis(DCA),and canonical correspondence analysis(CCA)methods were used.A total of 28 species,belonging to 27 genera in 8 families,were ***,Zygophyllaceae,Gramineae,and Leguminosae were the largest *** and perennial herbs accounted for 28.60%of the total number of plants,while shrubs(42.90%)were the most *** tangutorum was the constructive species of the desert plant *** divided the 68 plots surveyed in this study into 7 community types,according to the results of *** distribution of these 7 communities in the DCA ordination graph showed that species with a similar ecotype were clustered *** of CCA indicated that groundwater was the dominant factor influencing vegetation distribution,while distance between plot and oasis(Dis)and soil electrical conductivity(EC)were the local second-order *** study suggests that optimizing the utilization of groundwater in oases is key to controlling the degradation of desert *** favorable topographic conditions of sand dunes should be fully utilized for vegetal dune stabilization,and the influence of soil salinity on the selection of afforestation tree species should be considered.

关键词： TWINSPAN classification ordination desert plant groundwater oasis-desert ecotone species-environment relationship Minqin

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Geochemical characterization of major elements in desert sediments and implications for the Chinese loess source

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Science China Earth Sciences 2019年第9期62卷 1428-1440页

作者： Wancang ZHAO Lianwen LIU Jun CHEN Junfeng JI Chongqing Key Laboratory of Karst Environment School of Geographical Sciences Southwest University Chongqing 400715 China Ministry of Education Key Laboratory of Surficial Geochemistry School of Earth Sciences and Engineering Nanjing University Nanjing 210023 China

Mineral dust released from the desert is one of the important components of atmospheric aerosols. Arid and semi-arid deserts, sandy lands in northern China and their adjacent Gobi desert lands in northern China and neighboring Mongolia(hereinafter referred to as Gobi) are potential sources of mineral dust in Asia. However, there is currently a lack of systematic studies on the characteristics of major elements in the potential mineral dust source area. This study investigates the major elements of 310 surficial sand samples in the stabilized and semi-stabilized dune fields from 12 deserts/sandy land and Gobi in northern China and southern Mongolian Gobi and compiles published data. We identify four regions with distinct geochemical characteristics:(1) Taklimakan, Kumtag and Qaidam deserts in western China;(2) Badain Jaran, Tengger, Hobq, and Mu Us deserts in the central and western regions of northern China;(3) Hulun Buir, Onqin Daga and Horqin sandy lands in northeast China;and(4) Gobi and Gurbantunggut deserts. The spatial distributions of the SiO2 and CaO contents in Chinese deserts are highly variable. The average content of SiO2 generally reflects an increasing trend from west to east, while the average content of CaO shows a decreasing trend from west to east. We demonstrate that the spatial variation of major elements is likely controlled by two key scenarios: the composition of source rocks and the mineral maturity caused by the supply of fresh materials. The SiO2/(Al2O3+K2O+Na2O) ratio of desert sediments is relatively lower in western China and may be caused by high ferricmagnesia and high carbonate minerals;this ratio is relatively higher in the northeast sandy lands and may be linked to a lack of fresh material supply and the presence of high K-feldspar minerals in source rocks. The deserts can be further distinguished by ternary diagrams with SiO2/10-CaO-Al2O3,(K2O+Na2O)-CaO-Fe2O3 and CaO-Na2O-K2O. The comparison of major elements between desert sedimen

关键词： desert Loess Major elements Eolian Dust Carbonate

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Groundwater net discharge rates estimated from lake level change in Badain Jaran desert, Northwest China

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Science China Earth Sciences 2020年第5期63卷 713-725页

作者： Xingfan WANG Hui ZHAO Yongwei SHENG Jianwei GENG Keqi WANG Hongyu YANG Key Laboratory of desert and desertification Northwest Institute of Eco-Enviroment and ResourcesChinese Academy of SciencesLanzhou 730000China CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Department of Geography University of CaliforniaLos AngelesCA 90095USA

Over a hundred sizable lakes,some even larger than^1 km2,are distributed across the lowlands between megadunes in the southeastern Badain Jaran desert(BJD),northwest *** rather limited precipitation and hardly any surface runoff,these lakes are fed mainly by ***,the source of the groundwater and the groundwater discharge rates to these lakes are poorly *** level and temperature of four representative lakes in the southeastern BJD were monitored continuously between 2013 and *** surface evaporation and rainfall in this area were also *** these acquired data,groundwater discharge rates were estimated using water balance *** results show that the four lakes have similar recharge and discharge patterns,but at different average net groundwater discharge rates ranging from 1.79 to 3.09 mm d?*** lake level variation mainly depends on groundwater discharge and lake surface *** found that diurnal lake level variation may be controlled by earth tide and atmospheric pressure change,and is five times greater than the *** desert precipitation and deep confined groundwater with high temperature were found also recharging the desert *** Empirical Mode Decomposition(EMD)method was used to identify the lake level *** lake levels increased over the last four years,except one decreased in 2015 and *** lake levels’increasing trend is synchronously similar with the precipitation in north *** study analyzes annual and seasonal lake level variations,and also finds the diurnal water cycle between the groundwater and lake water for the first time.

关键词： Groundwater discharge Lake level Water balance Badain Jaran desert

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desert evolution and climatic changes in the Tarim River basin since 12 ka BP

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Science China Earth Sciences 1999年第S1期42卷 101-112页

作者：冯起苏志珠金会军 State Key Laboratory of Frozen Soil Engineering Institute of Glaciology and Geocryology Chinese Academy of Sciences Lanzhou Institute of desert Research Chinese Academy of Sciences

Climatic changes in the Tarim River basin since 12 kaBP were divided into four stages based on the analyses of sedimentary phase, the features of some climatic and environmental biomarks in the sedimentary strata and desert evolution. During the Holocene, cool-dry and temperate-dry climates resulted in apparent alluvial-fluvial and weak aeo-lian activities. During 10-8 kaBP, the climate was dry and cold, large-scale sand dunes activities led to regional desert expansion. During the hypsithermal (8-3 kaBP), the climate was dry and warm, shifting sand areas decreased and a lot of sand dunes were fixed along the banks of the Tarim River and its tributaries, lowlands and lakes. As a result, fluvial-alluvial areas increased. Since 3 kaBP, the aeolian activity and sandstorms have been enhancing due to the combined influences of climatic warming and illogical exploitation of land and water resources. The climate in the Tarim River basin have been persistently dry and alternated by warm and cold periods. Consequently, the sedimentary environments have varied from desert steppe to desert, and strongly influenced by periphery mountains and global climatic fluctuations .

关键词： Tarim River 12 kaBP desert evolution climatic changes.

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Soil Microbial Population in the Vicinity of the Bean Caper(Zygophyllum dumosum)Root Zone in a desert System

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Pedosphere 2007年第6期17卷 758-765页

作者： I.SHMUELI G.BARNESS Y.STEINBERGER The Mina & Everard Goodman Faculty of Life Sciences Bar-Ilan University Ramat-Gan 52900(Israel)

The aim of the current study was to gain a better understanding of the changes in soil microbial biomass and basal respiration dynamics in the vicinity of the bean caper （Zygophyllura duraosura） perennial desert shrub and the inter-shrub sites. Microbial biomasses as well as basal respiration were found to be significantly greater in the soil samples taken beneath the Z. duraosura shrubs than from the inter-shrub sampling sites, with no differences between the two sampling layers （0-10 and 10-20 cm） throughout the study period. However, seasonal changes were observed due to autumn dew formation, which significantly affected microbial biomass and basal respiration in the upper-layer inter-shrub locations. The calculated metabolic coefficient （qCO2） revealed significant differences between the two sampling sites as well as between the two soil layers, elucidating the abiotic effect between the sites throughout the study period. The substrate availability index was found to significantly demonstrate the differences between the two sites, elucidating the significant contribution of Z. duraosura in food source availability and in moderating harsh abiotic components. The importance of basal microbial parameters and the derived indices as tools demonstrated the importance and need for basic knowledge in understanding plant-soil interactions determined by an unpredictable and harsh desert environment.

关键词： basal respiration desert microbial biomass root zone soil

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Effects of geomorphology and soil conditions on vegetation structure in conserved desert wadis: A case study of Jal AlZor escarpment, Kuwait

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Journal of Mountain Science 2020年第3期17卷 588-601页

作者： Raafat H.ABDEl-WAHAB Mohammed A.BIHZAD Alham J.AL-LANGAWI Botany Department Faculty of ScienceSuez Canal UniversityIsmailia 41522Egypt Science Department College of Basic EducationPublic Authority for Applied Education and TrainingAdailiya 73251Kuwait

Variations in phytogeography of Jal Al-Zor wadi system in Sabah Al Ahmad Nature Reserve, an arid national park in Kuwait, in relation to physiographic and edaphic conditions were investigated using alpha diversity and multivariate analyses. A total of 66 plant species were recorded at low-relief and high-relief wadis. Altitude and slope gradients, grain size distribution and soil texture properties had a significant relationship with plant cover and plant diversity. There was a high diversity of life-forms along the wadi system with a dominant of therophytes(annuals) particularly in spring after winter rainfalls. Chamaephytes and hemicryptophytes were the dominant perennial life-forms. A chorological analysis documents the strong effect of Saharo-Arabian chorotype on the vegetation of the study area. Cluster analysis clarified eight vegetation assemblages along altitude and slope gradients within the wadi system. Alpha diversity of plant species was greater in plant assemblages at low-relief wadis than at high-relief wadis. Vegetation structure in this study showed that phytogeographically, wadis of Jal Al-Zor were closely related to the wadis in the Arabian deserts. The slope gradient pattern and edaphic conditions of plant assemblages and plant diversity in the conserved wadis of Jal Al-Zor may be suggested as a reference model for restoration strategy of disturbed low elevated wadis in the surrounding desert *** would include propagation of suitable plants such as Stipagrostis plumosa-Haloxylon salicornicum-Rhanterium epapposum.

关键词： Arabian desert Vegetation structure Wadi system Alpha diversity Clustering analysis

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Estimation and inter-comparison of dust aerosols based on MODIS, MISR and AERONET retrievals over Asian desert regions

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Journal of Environmental Sciences 2019年第2期31卷 154-166页

作者： Ammara Habib Bin Chen Bushra Khalid Saichun Tan Huizheng Che Tariq Mahmood Guangyu Shi Muhammad Tahir Butt Institute of Atmospheric Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science &Technology International Institute of Applied Systems Analysis Department of Environmental Science International Islamic University Key Laboratory of Atmospheric Chemistry (LAC) Institute of Atmospheric CompositionChinese Academy of Meteorological Sciences (CAMS)CMA Pakistan Meteorological Department Center for Environmental Protection Studies PCSIR Laboratories Complex

This study presents detailed analysis of spatiotemporal variations and trend of dust optical properties i.e., Aerosol Optical Depth(AOD) and Angstrom component over Asian desert regions using thirteen years of data(i.e., 2001–2013) retrieved from Aerosol Robotic Network(AERONET), Moderate Resolution Imaging Spectroradiometer(MODIS) and Multi-angle Imaging Spectroradiometer(MISR). These regions include Solar Village, Dunhuang and Dalangzadgad and are considered as origin of desert aerosols in Asia. Mann–Kendall trend test was used to show the trend of AOD. The relationship of AOD with weather parameters and general AOD trend over different wavelengths has also been shown. AOD's trend has been observed significant throughout the year in Solar Village, while in Dunhuang and Dalanzadgad the significant trend has been found only in peak period(March–June).Analysis show high values of AOD and low values of angstrom in Solar Village during peak period. In Chinese desert regions, high values of AOD have been found during peak period and low values in pre-peak period. Significant relationship has been observed between AOD and average temperature in Solar Village and Dalanzadgad whereas rainfall and wind speed showed no significant impact on AOD in all desert regions.

关键词： AOD Angstrom exponent AERONET MODIS MISR desert

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Site type classification for the shelter-forest ecological project along the Tarim desert Highway

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Chinese Science Bulletin 2008年第S2期53卷 31-40页

作者： LI BingWen XU XinWen LEI JiaQiang QIU YongZhi XU Bo ZHOU HongWei WANG Qiang WANG BO SU Wei College of Soil and Water Conservation Beijing Forestry UniversityBeijing 100083China Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China Tarim Branch PetroChina Company LimitedKorla 841000China

Site types of the afforestation region of the shelter-forest ecological project along the Tarim desert Highway were classified based on the natural conditions and windblown sand damages. The extremely severe environment, the irrigation with saline water, and large-scale linear project makes this classification of site types most unique and significant. It adopted a three-level classification system integrating the dominant factors and restrictive factors in regard to their impacts on plant survival and growth as well as on the protective property. Six site type districts were classified based on the medium-scale geomorphic unit, the windblown sand damages, and the major production facilities; 21 site type groups were obtained according to the small-scale geomorphic type, terrain, and wind regime; 36 site types were further classified based on the salt contents of the underground water and soil types. Especially, in this study, spatial distribution of the six site type districts along the desert highway is continuous, which is unique and different from that of most other classifications. In addition, the salt-stress tolerance threshold of the main afforestation plant species to underground water have been set to 8 g/L and 15 g/L according to selective breeding tests and the salinity spatial distribution of the underground water. Thus, the underground water with salinity lower than 8 g/L is defined as light saline water in this area.

关键词： Tarim desert Highway shelter-forest site type classification saline water Xinjiang afforestation

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Spatio-Temporal Effect on Soil Respiration in Fine-Scale Patches in a desert Ecosystem

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Pedosphere 2006年第1期16卷 1-9页

作者： S. PEN-MOURATOV M. RAKHIMBAEV Y. STEINBERGER Faculty of Life Sciences Bar-Ilan University Ramat-Gan 52900 (Israel) Faculty of Life Sciences Bar-Ilan University Ramat-Gan 52900 (Israel) Institute of Botany Tashkent (Uzbekistan)

Soil organisms in terrestrial systems are unevenly distributed in time and space, and often aggregated. Spatiotemporal patchiness in the soil environment is thought to be crucial for the maintenance of soil biodiversity, providing diverse microhabitats tightly interweaving with resource partitioning. Determination of a ＂scale unit＂ to help understand ecological processes has become one of the important and most debatable problems in recent years. A fieldwork was carried out in the northern Negev desert highland, Israel to determine the influence of fine-scale landscape patch moisture heterogeneity on biogeochemical variables and microbial activity linkage in a desert ecosystem. The results showed that the spatio-temporal patchiness of soil moisture to which we attribute influential properties, was found to become more heterogenic with the decrease in soil moisture availability （from 8.2 to 0.4 g kg^-1） toward the hot, dry seasons, with coefficient of variation （CV） change amounting to 66.9%. Spatio-temporal distribution of organic matter （OM） and total soluble nitrogen （TSN） was found to be relatively uniformly distributed throughout the wet seasons （winter and spring）, with increase of relatively high heterogeneity toward the dry seasons （from 0.25% to 2.17% for OM, and from 0 to 10.2 mg kg^-1 for TSN） with CV of 47.4% and 99.7% for OM and TSN, respectively. Different spatio-temporal landscape patterns were obtained for Ca （CV = 44.6%）, K （CV = 34.4%）, and Na （CV = 92%） ions throughout the study period. CO2 evolution （CV = 48.6%） was found to be of lower heterogeneity （varying between 2 and 39 g CO2-C g^-1 dry soil h^-1） in the moist seasons, e.g., winter and spring, with lower values of respiration coupled with high heterogeneity of Na^＋ and low levels of TSN and organic matter content, and with more homogeneity in the dry seasons （varying between 1 and 50 g CO2-C g^-1 dry soil h^-1）. Our results elucidate the heterogeneity and complexity of desert system habitats

关键词： desert microbial respiration patchiness small-scale habitat soil

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Processes of the deposition and vicissitude of Mu Us desert,China since 150 ka B.P.

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Science China Earth Sciences 1998年第3期41卷 248-254页

作者：李保生靳鹤龄吕海燕祝一志董光荣孙东怀张甲坤高全洲闫满存 1. Geography Department of South China Normal University 510631 Guangzhou China 2. Lanzhou Institute of desert Research Chinese Academy of Sciences 730000 Lanzhou China 3. Graduate School China University of Geosciences 430074 Wuhan China 4. Xi'an Laboratory of Loess & Quaternary Geology Chinese Academy of Sciences 710061 Xi'an China 5. Guangzhou Institute of Geochemistry Chinese Academy of Sciences 510650 Guangzhou China

Milanggouwan stratigraphical section" named lately takes down 27 cycles of alternately evolutionary histories of desert depositions in the Mu Us area with the fluviolacustrine facies and palaeosols since 150 ka B.P. Studies show that the sedimentary form was induced by the growth and decline and confrontation each other between the winter monsoon and the summer monsoon of East Asia in the past 150 ka.

关键词： Mu Us desert Milanggouwan stratigraphical section 150 ka 27 periods of desert depositions.

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