Effect of stand age and individual growth on seed germination of Populus euphratica in the Ejina Oasis, China

We conducted an investigation into the germination of seeds from individual Populus euphratica trees of different ages and growing conditions in order to discover the effect of intraspecific factors on their sexual reproduction in the Ejina Oasis, Inner Mongolia of China. By carrying out germination experiments of seeds collected at various seed dispersal periods, we found that P. euphratica seeds could be germinated intensively within 8 h from the start of the experiments, that the germination percentage decreased with the time of seed dispersal and that the germination percentage of seeds collected at the early stage of seed dispersal was 1.86 times greater than those collected at the final stage. There was no significant difference in the germination percentage or the germination index between seeds collected at the early and peak stages. The vitality of seeds from the mature forest was clearly higher than that of the half-mature and near-mature forests. The rate of branch dieback only affected seed germination at the final stage. Therefore, we conclude that the mature P. euphratica forest was the main contributor to reproduction. The results show that both the time of seed harvest and stand age were the main factors affecting the germination percentage of P. euphratica seeds.

Plant diversity and its maintenance in Populus euphratica riparian forests in the Ejina Oasis,China

The dynamic environments in riparian zones support a variety of life-history strategies, which constitute a fundamental mechanism for development and maintenance of biodiversity in riparian forest ecosystems. To demonstrate the effect of life-history strategies on biodiversity, we investigated community-level diversity and its relationship to environmental variability in the riparian Populus euphratica forests of the Ejina Oasis. Communities were divided into 14 associations on the basis of their species impor- tance values. The Simpson＇s index, Shannon-Wiener index, Pielou＇s evenness index and the regional Whittaker＇s index were applied to calculate community diversity. An ordination of the sample plots was carried out by correspondence analysis （CA）. Biodiversity was relatively low across the entire study area, but there was high community diversity （flw = 8.09） due to the spatial heterogeneity of habitats in different plots. In addition, we investigated the relationship between biodiversity and several environmental factors, such as water availability, community components and soil conditions. We conclude that the heterogeneity of soil and water availability drives community diversity patterns in riparian zones and that community-level diversity favors the maintenance of species diversity in the P euphratica forests in the Ejina Oasis.

How changes of groundwater level affect the desert riparian forest ecosystem in the Ejina Oasis,Northwest China

Groundwater is a key factor controlling the growth of vegetation in desert riparian systems. It is important to recognise how groundwater changes affect the riparian forest ecosystem. This information will not only help us to understand the ecological and hydrological process of the riparian forest but also provide support for ecological recovery of riparian forests and water-resources management of arid inland river basins. This study aims to estimate the suitability of the Water Vegetation Energy and Solute Modelling(WAVES) model to simulate the Ejina Desert riparian forest ecosystem changes,China, to assess effects of groundwater-depth change on the canopy leaf area index(LAI) and water budgets, and to ascertain the suitable groundwater depth for preserving the stability and structure of desert riparian forest. Results demonstrated that the WAVES model can simulate changes to ecological and hydrological processes. The annual mean water consumption of a Tamarix chinensis riparian forest was less than that of a Populus euphratica riparian forest, and the canopy LAI of the desert riparian forest should increase as groundwater depth decreases. Groundwater changes could significantly influence water budgets for T. chinensis and P. euphratica riparian forests and show the positive and negative effects on vegetation growth and water budgets of riparian forests. Maintaining the annual mean groundwater depth at around 1.7-2.7 m is critical for healthy riparian forest growth. This study highlights the importance of considering groundwater-change impacts on desert riparian vegetation and water-balance applications in ecological restoration and efficient water-resource management in the Heihe River Basin.

Characterization of groundwater in the Ejina Basin,northwest China:hydrochemical and environmental isotopes approaches

To characterize the groundwater in the Ejina Basin,surface and groundwater samples were collected in May and October of 2002.On-site analyses included temperature,electrical conductance(EC),total alkalinity(as HCO 3) by titration,and pH.Chemical analyses were undertaken at the Geochemistry Laboratory of the Cold and Arid Region Environmental and Engineering Institute,Chinese Academy of Sciences,Lanzhou,China.The pH of the groundwater ranged from 7.18 to 8.90 with an average value of 7.72,indicating an alkaline nature.The total dissolved solids(TDS) of the groundwater ranged from 567.5 to 5,954.4 mg/L with an average of 1,543.1 mg/L and a standard deviation of 1,471.8 mg/L.According to the groundwater salinity classification of Robinove et al.(1958),47.4 percent of the samples were brackish and the remainder were fresh water.The ion concentration of the groundwater along the riverbed and near the southern margin of the basin were lower than those farther away from the riverbed.The groundwater in the study area was of Na +-HCO 3 type near the bank of the Heihe River and in the southern margin of the basin,while Na +-SO 4 2-Cl type samples were observed in the terminal lake region.In the desert area the groundwater reached a TDS of 3,000-6,000 mg/L and was predominantly by a Na +-Cl chemistry.Br/Cl for the water of Ejina Basin indicates an evaporite origin for the groundwater with a strongly depleted Br/Cl ratio(average 0.000484).The surface water was slightly enriched in Br/Cl(average 0.000711) compared with groundwater.The calculated saturation index(SI) for calcite and dolomite of the groundwater samples range from 0.89 to 1.31 and 1.67 to 2.67 with averaged 0.24 and 0.61,respectively.About 97 percent of the groundwater samples were kinetically oversaturated with respect to calcite and dolomite,and all the samples were below the equilibrium state with gypsum.Using isotope and hydrochemical analyses,this study investigated the groundwater evolution and its residence time.The groundwater content was mainly determined by the dissolutions of halite,gypsum,and Glauber’s salt(Na 2 SO 4),as well as Na + exchange for Ca 2+,and calcite and dolomite precipitation.With the exception of a few locations,most of the groundwater samples were suitable for irrigation uses.Most of the stable isotope compositions in the groundwater sampled plotted close to the Global Meteoric Water Line(GMWL),indicating that the groundwater was mainly sourced from meteoric water.There was evidence of enrichment of heavy isotopes in the groundwater due to evaporation.Based on the tritium content in atmospheric precipitation and by adopting the exponential-piston model(EPM),the mean residence time of the unconfined aquifer groundwater was evaluated.The results show that these groundwaters have low residence time(12 to 48 years) and are renewable.In contrast,the confined groundwater had 14 C ages estimated by the Pearson model between 4,087 to 9,364 years BP.Isotopic signatures indicated formation of deep confined groundwaters in a colder and wetter climate during the late Pleistocene and Holocene.

The research of three-dimensional numerical simulation of groundwater-flow: taking the Ejina Basin, Northwest China as example

Water is a primary controlling factor for economic development and ecological environmental protection in the inland river basins of arid western China. And it is groundwater, as the most important component of total water resources, that plays a dominant role in the development of western China. In recent years, the use-ratio of surface water has been raised, the groundwater recharge rate from surface water has been reduced, and groundwater has been exploited on a large scale. This has led to the decline of ground-water levels and the degradation of eco-environments in the Heihe watershed. Therefore, the study on the change in groundwater levels in recent years, as well as simulating and predicting groundwater levels in the future, have become very significant for im-proving the ecological environment of the Heihe River Basin, to coordinate the water contradiction among upper, middle and lower reaches of Heihe River Basin and to allocate the water resources. The purpose of this study is to analyze the groundwa-ter-level variations of the Ejina region based on a large scale, to develop and evaluate a conceptual groundwater model in Ejina Basin, to establish the groundwater flow model using the experimental observation data and combining Modular Three-Dimensional Groundwater Flow Model (MODFLOW) and GIS software, to simulate the regional hydrologic regime in re-cent 10 years and compare various water-delivery scenarios from midstream, and to determine which one would be the best plan for maintaining and recovering the groundwater levels and increasing the area of Ejina oasis. Finally this paper discusses the pos-sible vegetation changes of Ejina Basin in the future.

Characteristics of biomarkers in source rocks of the Ganquan Formation in the Dahulishan region, Ejina Banner

Based on gas chromatography and gas chromatography mass spectrometry techniques, the authors examined biomarker characteristics of the Ganquan Formation source rocks in the area of Dahulishan, Ejina, and analyzed the information and petroleum geological significance that were indicated by the source of organic matter, sedimentary environment and maturity and so on. Gas chromatography peak of saturated hydrocarbons from the Ganquan Formation source rocks showed "the former peak" of the single peak distribution, the main peak of carbon being C18 , indicating the main sources of organic matter with marine organic matter. Pr/Ph ranges from 0.3 to 0.6, indicating a strongly reducing sedimentary environment. Biomarker assemblages of the Ganquan Formation source rocks are abundant in tricyclic terpane with long side chains, with a high level of gammacerane, showing dominant distribution of C27 sterane. High contents of gammacerane in organic matter show organic facies of source rocks in the saltwater sedimentary environment. That average hopane/sterane ratio is 0.59, showing that algae have made more contributions to organic matter than bacteria. And the high level of C27 steranes shows that algae are the main source of hydrocarbon precursors. The Ganquan Formation's methylphenanthrene index, which is an effective molecular parameter index to measure thermal evolution of organic matter, ranges from 0.35 to 0.50, and the conversion of vitrinite reflectance Rc from it is within the range of 2.00-2.09, indicating that the Ganquan Formation source rocks are in the over-mature stage of thermal evolution.

内蒙古额济纳旗格日勒图铜多金属矿成因及找矿潜力

内蒙古珠斯楞地区为我国北山成矿带的东延区,格日勒图铜多金属矿是近些年在该区发现的重要铜多金属矿床,矿床赋存于上石炭统白山组上段(C_(2)b^(2))火山岩中。为研究该矿床的成因类型,本文开展了矿石矿物组构、矿石地球化学、石英包裹体和矿物电子探针等分析测试。结果表明,矿石中的脉石矿物主要为石英,石英中包裹体气液比15%~40%,均一温度156℃~395℃,平均温度为308.7℃。盐度(wt%NaCl)2.41~6.64,平均为4.34,属于低盐度中高温流体。石英中的气体包裹体可分为两种类型,一类为N_(2)+CH_(4),另一类为N_(2)。综合研究认为该矿床的成因类型为岩浆热液型矿床。铜多金属矿体在垂向具有明显的分带,上部发育高品位的次生富集带,金属硫化物主要为蓝辉铜矿、辉铜矿、黄铁矿、闪锌矿和少量的砷黝铜矿、黄铜矿等;下部主要为黄铁矿、闪锌矿、方铅矿、黄铜矿和砷黝铜矿等。矿床的形成可初步划分为火山沉积成岩期、岩浆热液成矿期和表生成矿期。研究认为在该矿床深部及外围地区依然具有较大的找矿潜力。

Why lowland riparian trees are difficult to use for streamflow reconstruction

Existing streamflow reconstructions based on tree-ring analysis mostly rely on species from upland,mainly montane areas,while lowland species(generally plain)areas are rarely used.This limits the understanding of streamflow change history in the lowlands,which is an important basis for water resource management.This study focused on Populus euphratica stands located along the main stream,eastern and western tributaries in the lower reaches of the Heihe River basin(HRb),in arid northwestern China.We investigated how streamflow regulation interferes with ripar-ian trees in lowlands when they used for streamflow recon-struction.Tree-ring width chronologies were developed and analyzed in conjunction with meteorological and hydrologic observation data.The results show streamflow regulation leads in sharp fluctuations in the streamflow allocation between the eastern tributaries and western tributaries.This resulted in instability of the correlation between streamflow at the two tributaries and at the Zhengyixia hydrologic station,with corresponding fluctuations in radial growth of poplar trees on the banks of the two tributaries and at the station.Streamflow regulation altered the natural patterns of seasonal streamflow below the station,changing the time window of poplar response.This study provides useful insight into tree-ring width based streamflow reconstruction in the lowlands.

Study on vegetation ecological water requirement in Ejina Oasis

The Ecological Water Requirement (EWR) of desert oasis is the amount of water required to maintain a normal growth of vegetation in the special ecosystems. In this study EWR of the Ejina desert oasis is estimated through the relational equation between normalized difference vegetation index (NDVI), productivity and transpiration coefficient, which was established by a combination of the RS, GIS, GPS techniques with the field measurements of productivity. The results show that about 1.53×108 m3 water would be needed to maintain the present state of the Ejina Oasis, and the ecological water requirement would amount to 3.49×108 m3 if the existing vegetation was restored to the highest productivity level at present. Considering the domestic water requirement, river delivery loss, oasis vegetation water con-sumption, farmland water demand, precipitation recharge, etc., the draw-off discharge of the Heihe River (at Longxin Mount) should be 1.93×108―2.23 ×108 m3 to maintain the present state of the Ejina Oasis, and 4.28×108―5.17×108 m3 to make the existing vegetation be restored to the highest productiv-ity level at present.

Responses of distribution pattern of desert riparian forests to hydrologic process in Ejina oasis

By using the theories and methods of landscape ecology and the technology of GIS and RS, a study has been carried out on the responses of distribution pattern of desert riparian forest to hydrologic process on the basis of the hydrologic data from 1990 to 2000 and the TM image of 2001 year. The results showed that: (1) there appears an even distribution pattern for the relative forest area in oasis, however, the degenerated forest diaplays an increasing tendency from west to east; (2) the desert riparian forest in Ejina is in completely degenerated process at the patch scale; (3) the number of patch is influenced not only by hydrologic process,but also by agricultural activity such as cultivation. The severe deterioration of the degraded vegetation in whole oasis initiates from lower reaches, and gradually impels to upstream; the fragmentation of landscape in the terminal site is more obvious, which is influenced by river shape and decreasing flux of water. It is found that the influence of surface hydrologic process to the ground hydrologic process of desert riparian forest in Ejina oasis is little for the recent ten years. The relative area of the degenerated forest increased with increasing ground water depth in the direction of parallel to river channel. On the contrary, in the direction perpendicular to river channel, there is a decreasing tendency for the average patch area of the forest and the degenerated forest with increasing ground water depth.

额济纳绿洲植被恢复潜力研究

为分析黑河尾闾额济纳绿洲生态治理效果及未来植被恢复潜力,基于2000—2020年MOD13Q1数据集提取归一化植被指数(NDVI),运用Sen斜率估计和M-K检验分析了额济纳绿洲植被时空变化特征,并利用像元二分模型、相似生境法探讨了额济纳绿洲植被覆盖度、未来植被恢复潜力。结果表明:2000—2020年NDVI呈增大趋势,增长速率为0.001 3/a,季节尺度上春季NDVI呈显著增大趋势的面积占比最大;额济纳旗政府所在地附近植被覆盖度较高,研究期内西河中游区域植被覆盖度增长明显;未来植被仍呈现两河周边高、绿洲边缘低的空间分布格局,黑河尾闾湖泊周边等已经接近或达到最大植被恢复潜力,八道河至天鹅湖河道、七道河尾部河道、四道河与六道河河道尾部以及西河下段西部等区域植被提升潜力较大。

内蒙古额济纳旗东北部雅干断裂带深部构造特征分析——来自大地电磁的证据

内蒙古额济纳旗东北部雅干断裂带的空间展布及深部构造特征一直存在争议。本文按照“由已知到未知”的研究思路,在研究区内完成5条大地电磁测深剖面,首先对研究区内西侧大地电磁剖面MT01的电性结构特征与剖面区段内所出露的雅干断裂带地质构造信息之间的关系进行了深入分析,确定了雅干断裂带的电性特征表现为“北倾+大倾角+大深度”的电阻率梯级带,并以此作为特征标志,结合区内东侧覆盖区内4条MT剖面(MT02~MT05)反演解释结果,识别出各剖面区段内雅干断裂带的深部位置及构造特征。同时,采用阻抗张量分解技术获得了各条MT剖面的电性主轴方向,结合二维反演解释结果确定了雅干断裂带空间走向。结果表明,研究区内雅干断裂带在浅地表处总体走向为近EW向(深部为NE45°),平均宽度约6.8 km,是一条由西向东且逐渐向北弧形偏转的逆断层,断层倾向总体向北,断层倾角60°~67°,断层深度约20 km。本文所获得的深部电性结构模型有效地揭示了研究区内深部构造特征,对于区域构造演化研究具有一定的参考意义。

额济纳汉简书法鉴赏与创作的审美理路

额济纳出土的简牍是两汉时期书法墨迹,是汉代书法“隶书草化”的缩影。额济纳汉简书法鉴赏与创作过程中可见“象、法”的书法形式要素以及以“媚美”为形式规定的法度特征与以“自由”为内容追求的书意特征,由此升华出从“书法意象”到“书法意境”的额济纳汉简审美理路。

额济纳旗下陶勒盖西矿段深部铜矿体地质特征及找矿方向浅析

内蒙古自治区额济纳旗下陶勒盖铁矿大地构造位置位于天山地槽褶皱系(Ⅰ)、北山晚华力西地槽褶皱带(Ⅱ),三级构造单元为北山隆起(Ш),属古亚洲成矿域,准格尔成矿省,觉罗塔格-黑鹰山Cu、Ni、Fe、Au、Ag、Mo、W、石膏成矿带,黑鹰山-雅干Fe、Au、Cu、Mo成矿亚带,下陶勒盖西矿段深部铜矿体主要赋存于石炭系下统绿条山组第二岩段的大理岩与华力西期钾长花岗岩接触带附近的矽卡岩中。

^(10)Be in quartz gravel from the Gobi Desert and evolutionary history of alluvial sedimentation in the Ejina Basin,Inner Mongolia,China

Reconstructing the evolutionary history of the Gobi deserts developed from alluvial sediments in arid regions has great significance in unraveling changes in both tectonic activity and climate.However,such work is limited by a lack of suitable dating material preserved in the Gobi Desert,but cosmogenic 10Be has great potential to date the Gobi deserts.In the present study,10Be in quartz gravel from the Gobi deserts of the Ejina Basin in Inner Mongolia of China has been measured to assess exposure ages.Results show that the Gobi Desert in the northern margin of the basin developed 420 ka ago,whereas the Gobi Desert that developed from alluvial plains in the Heihe River drainage basin came about during the last 190 ka.The latter developed gradually northward and eastward to modern terminal lakes of the river.These temporal and spatial variations in the Gobi deserts are a consequence of alluvial processes influenced by Tibetan Plateau uplift and tectonic activities within the Ejina Basin.Possible episodes of Gobi Desert development within the last 420 ka indicate that the advance/retreat of alpine glaciers during glacial/interglacial cycles might have been the dominant factor to influencing the alluvial intensity and water volume in the basin.Intense floods and large water volumes would mainly occur during the short deglacial periods.

内蒙古额济纳平原地下水氢氧稳定同位素和水化学特征及其演化规律

【研究目的】为研究内蒙古额济纳平原地下水水化学特征及其演化规律,于2020年8月采集水样87组,氢氧同位素样品69组。【研究方法】综合运用数理统计、离子比例分析、水文地球化学模拟等方法,分析额济纳平原第四系地下水及北部白垩系地下水水文地球化学特征,探讨水文地球化学演化规律。【研究结果】结果表明:(1)该区地下水水化学类型以SO4-Na型为主。地下水中阴离子以SO42-为主,其次为Cl-;阳离子以Na+为主,Ca2+与Mg2+浓度差异不大。(2)研究区地下水SO42-、Cl-、TDS、总硬度、Na+和Mg2+浓度具有第四系承压水>第四系潜水>白垩系承压水的特点。(3)第四系潜水离子组分主要受溶滤作用、混合作用控制,局部地区受蒸发作用影响显著;第四系承压水离子组分主要受溶滤作用和阳离子交换作用控制;平原北部白垩系承压水离子组分受溶滤作用及阳离子交换作用控制。研究区地下水中主要离子来自岩盐、碳酸岩盐和石膏的溶解。【结论】沿地下水流向,第四系潜水离子浓度组分呈增加趋势,在额济纳平原内部第四系潜水和承压水中主要发生岩盐、白云石和石膏溶解、方解石沉淀以及正向阳离子交换作用;研究区东南部沙漠与平原交错带主要发生岩盐、白云石和石膏溶解、方解石沉淀以及反向阳离子交换;平原区北部白垩系承压水中主要发生岩盐、白云石和石膏溶解、方解石沉淀以及正向阳离子交换。

基于水化学与环境同位素的额济纳平原区域地下水循环规律解析

额济纳平原生态环境脆弱,地下水在维持当地生态方面发挥着重要作用。然而,对具有重要生态水文意义断面上地下水循环过程关注不够,阻碍了对额济纳平原地下水循环规律的深入认识。本研究采用水化学与同位素方法解析额济纳平原关键界面地下水循环特征,归纳区域地下水循环模式。结果表明:沙漠区降雨在入渗补给地下水过程中受到过强烈的蒸发影响,研究区中部降雨对地下水补给微弱;额济纳平原北部白垩系潜水接受侧向径流补给,自北向南径流,至东、西居延海一带与南部第四系地下水流系统交汇,白垩系承压水径流滞缓,与上覆潜水水力联系微弱;黑河渗漏强烈影响深度30~50 m,强烈影响宽度10 km,平原中部地下水接受黑河渗漏补给后驱动两侧年龄较老的地下水缓慢侧向径流,在古日乃湖至天鹅湖一带与东部沙漠区地下水流系统交汇,黑河河水与沙漠区地下水不存在补排关系。该研究深化了对额济纳平原地下水循环的认识,对当地生态环境保护与修复、地下水合理开发利用具有指导意义。

内蒙古额济纳旗格日勒图铜多金属矿深部综合信息提取及其指示意义

内蒙古额济纳旗格日勒图铜多金属矿床位于成矿地质背景优越的北山成矿带,是近几年新发现的矿床,然而,前人针对矿床深部蚀变矿物类型、地质体磁化率、成矿及相关蚀变元素分布特征研究相对不足,制约了勘查效率的提高。本文以该矿床为例,使用便携式短波红外(SWIR)光谱仪、X射线荧光光谱仪(XRF)以及手持磁化率仪对矿区钻孔岩心蚀变特征、成矿元素分布特征和磁化率特征进行研究,识别出主要蚀变矿物有高岭石、钾伊利石、针铁矿、白云母、赤铁矿、埃洛石以及白云石等。在垂向上,从上至下与铜矿化关系密切的3类蚀变矿物组合依次为:埃洛石+白云石、白云母+铁镁绿泥石、高岭石+钾伊利石。成矿元素分布特征表明,Cu、Pb、Zn、Ag元素XRF分析结果与地质剖面中矿化层化学分析结果趋势基本一致,岩心中绢英岩XRF分析结果值较高,绢英岩化可作为重要的找矿标志,另外Fe可以作为判断地质体矿化信息指示性元素,As分布较集中于浅部矿层中,在矿化部位含量较高,认为As元素可以作为判定浅部矿化体的指示性元素。钻孔岩心显示磁化率有玄武岩>(矿化)绢英岩>绢英岩>流纹岩>安山岩、云母石英片岩的变化特点。研究结果表明,矿区内蚀变矿物组合关系、成矿元素分布特征、高磁化率对矿区勘查找矿具有理论指导意义。

内蒙古北山地区中基性岩脉年代学和地球化学特征:对塔里木板块北缘构造演化的启示

塔里木板块北缘额济纳旗老硐沟金矿床发育系列蚀变中基性岩脉,其形成时代与成因对制约金成矿作用及区域古亚洲洋的演化提供了研究窗口。本文在老硐沟金矿区Ⅱ矿段采集系列辉绿岩脉及与金成矿相关的蚀变闪长玢岩脉样品,进行了锆石LA-ICP-MS U-Pb定年、Hf同位素组成和全岩元素分析。结果表明,辉绿岩脉和闪长玢岩脉侵位时代分别为(286.5±1.7)Ma和(243.2±1.1)Ma,即早二叠世和中三叠世,二者年龄先后顺序与野外观察的交切关系相符。根据金矿体穿插闪长玢岩脉的特征,限定金成矿时代略晚于243 Ma。辉绿岩脉锆石εHf(t)为-3.67~0.97,全岩元素组成表现为准铝质钙碱性系列,反映岩浆源区既有新元古代新生地壳组分,又有中元古代古老地壳组分。蚀变闪长玢岩脉εHf(t)=-0.07~-4.76,全岩元素组成是过铝质钾玄岩系列(富钾特征受到矿区钾化蚀变的影响),指示其岩浆主要源于中元古代的地壳物质熔融。综合塔里木地块北缘晚古生代至早中生代构造演化史,提出晚石炭世—早二叠世北山地区古洋盆消减,洋壳俯冲导致地幔楔部分熔融,岩浆上侵至浅部断裂冷却形成辉绿岩脉;早二叠世末期北山地区进入陆内演化阶段,中三叠世产生造山后伸展作用,导致中元古代的地壳物质发生减压熔融,岩浆沿地壳断裂上侵、就位形成闪长玢岩脉。

1977—2020年额济纳胡杨林植被变化特征及其影响因子分析

基于1977—2020年Landsat影像,采用监督分类和归一化植被指数(NDVI),并结合气象、水文数据,对近44年额济纳绿洲胡杨林面积时空动态、植被状况,以及对其有影响的主要环境因素进行综合分析。结果表明:(1)2020年胡杨林面积为2.99万hm~2,较1977年增长了1.62倍,东河西岸三角洲恢复面积较大。研究期内,胡杨林经历了衰落期和恢复期,最小面积为1990年的1.03万hm~2。(2)2001年实施生态调水后,研究区NDVI值增速达0.027/10 a(P<0.01),是研究时段NDVI值增速的2倍、调水前NDVI值增速的45倍。(3)虽然月NDVI值与月均温相关系数为0.463(P<0.01),但年NDVI值与气候因素相关性并不明显,而与正义峡径流量显著正相关(相关系数为0.437,P<0.05),并且实施黑河调水与胡杨林景观生态功能改善的时间段同步。生态调水后,研究区NDVI值升高了0.011,裸地面积减少0.17万hm~2。