首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
新疆塔里木河下游物种多样性与地下水位的关系   总被引:5,自引:0,他引:5  
郝兴明  陈亚宁  李卫红 《生态学报》2007,27(10):4106-4112
依据塔里木河下游7个监测断面36眼地下水位观测井和36个植物样地野外采集的数据,应用Margalef丰富度指数、Shannon-Weiner信息指数、Alatalo均匀度指数和修正的Simpson多样性指数以及含参数的Hill指数,对塔里木河下游物种多样性特征进行了分析。结果表明:塔里木河下游物种多样性与地下水埋深有显著的关联性,随着地下水埋深增大,塔里木河下游物种丰富度和多样性均表现出递减趋势,而均匀度指数的变化趋势则不甚明显;Hill指数的分析表明,以地下水埋深6m和10m为界,多样性变化明显分为3个不同的变化阶段,其中地下水埋深在6m以下时,多样性锐减,且曲线最终趋于平直。综合野外调查和样地资料分析,认为塔里木河下游物种多样性受损的临界地下水位为6m左右。  相似文献   

2.
于塔里木河中游地区选取30个样地,并采集相应地区30眼地下水位监测井的数据。根据监测井的地下水位检测数据,将地下水位按不同埋藏深度划分为0~2 m、2~4 m、4~6 m、6~8 m、8~10 m、>10 m共6个梯度,对不同地下水埋深下的样地群落盖度、物种多样性进行分析,以探讨主要植物分布频率与地下水埋深的关系,明确塔里木河中游地区荒漠河岸林植被的合理生态水位,为塔里木河中游地区乃至全流域的生态系统恢复提供依据。结果显示:(1)塔里木河中游地区共出现植物15种,其优势种植物为胡杨。(2)随着地下水位的降低,植被的盖度逐渐减小;当地下水位介于2~4 m时,植被的盖度平均为39.14%,当地下水埋深介于6~8 m时,植被的覆盖度小于20%;当地下水位低于10 m时,植被的平均覆盖度仅为7.65%。(3)随着地下水位的降低,研究区内的各类物种多样性指数均呈先增加后降低的趋势,一般在地下水埋深2~4 m时物种的多样性最高,其次为4~6 m和0~2 m;当地下水位在6 m以下时,物种的多样性锐减,地下水位低于10 m时,物种仅存柽柳和胡杨,多样性降至很小。(4) 塔里木河中游地区植物所要求的地下水平均深度为:胡杨4.58 m、柽柳3.53 m、芦苇2.34 m、骆驼刺4.10 m、花花柴3.18 m、黑刺2.98 m,只有芦苇适宜较浅的地下水埋深(≤2.5 m),其余的均宜在3~4 m左右。研究表明,在塔里木河中游地区,最适宜植物生长的地下水位为2~4 m,能够保证植物正常生长的合理地下水埋深区间为2~6 m。因此,要使塔里木河中游地区的植被得到恢复并确保其正常生长,区域内的地下水位应确保在6 m以上。  相似文献   

3.
新疆塔里木河下游应急输水植被阶段恢复分析   总被引:14,自引:1,他引:13  
李霞  侯平  董新光  朱小虎 《生态学杂志》2005,24(12):1449-1453
根据塔里木河下游第4次应急输水后不同断面、不同离河距离植被生长调查数据,分析塔里木河下游输水河道两侧不同地下水埋深梯度地表相应植物的生态恢复指征,结果表明,经4次应急输水后胡杨萌蘖更新发生在离河150m且地下水埋深<4m的条件下,研究确定了植被种类、长势与离河距离和地下水埋深之间的量化关系以及植被恢复等级与离河距离的量化关系,为应急输水后生态恢复范围的确定和输水方案的调整提供科学依据.  相似文献   

4.
塔里木河下游干旱胁迫下多枝柽柳茎水势的变化   总被引:5,自引:1,他引:4  
于2005-2006年对新疆塔里木河下游亚合浦马汗和阿拉干断面多枝柽柳(Tamarix ramosissima)茎水势进行了测定.结果表明:多枝柽柳茎水势日变化规律与其它植物水势不同,8:00较高,14:00和20:00较低,20:00以后略呈上升趋势,说明在塔里木河下游气温不是影响多枝柽柳水势变化的主导因素;对多枝柽柳茎水势和地下水埋深、土壤盐分进行相关分析表明,多枝柽柳茎水势与地下水埋深之间呈显著负相关性,与土壤盐分不具有显著相关性,说明塔里木河下游多枝柽柳茎水势对地下水埋深的变化响应强烈,对土壤盐分的变化响应不强烈.该研究可为塔里木河下游进行有效的生态输水,加速受损生态系统的恢复提供科学依据.  相似文献   

5.
塔里木河下游荒漠植被保护酶活性与地下水位变化的关系   总被引:2,自引:0,他引:2  
在塔里木河下游的不同断面,随着距离河道由近及远、地下水埋深的不断增大,柽柳叶片的MDA含量、SOD活性随着地下水位的下降而逐渐增加,与地下水位呈显著正相关.相关系数分别为0.7464和0.5531;POD活性却随着地下水埋深的不断增大而呈下降趋势,与地下水位呈显著负相关.相关系数为0.5518。根据不同地下水位条件下柽柳叶片的MDA含量和SOD活性所反映出的适宜其生存的合理生态水位、(严重)胁迫水位并将其进行综合比较与分析,初步推断出:在塔里木河下游地下水埋深超过3.12m时.柽柳的生长即开始受到抑制,5m左右的地下水位即对柽柳造成严重胁迫,≥8.83m的地下水位则会危及柽柳的生存。  相似文献   

6.
本研究基于沙漠腹地达理雅博依绿洲地下水埋深资料,利用年轮测定方法,分析了不同地下水埋深状况下柽柳年轮宽度的变化,探讨了其与地下水埋深变化的关系。研究显示:样地一地下水埋深随时间逐年增加,埋深范围是1.2-2.6 m,柽柳的年轮宽度在2001-2020年间呈显著增加趋势,变化范围在0.98-5.80 mm,年轮宽度年际间差异显著;样地二地下水埋深随着时间增长呈现先增加后减小的趋势,埋深范围是2.7-4.5 m,柽柳年轮宽度在1977-2020年间整体呈正弦函数变化,范围在1.46-4.41 mm,年轮宽度年际间差异性不显著;样地一柽柳标准年表振幅范围是0.502-1.641,大于样地二柽柳标准年表振幅范围0.577-1.331。以上结果表明样地一地下水埋深向着柽柳生长适宜的范围增加时,有利于柽柳的生长,表现为年轮宽度增加,样地二的柽柳年轮宽度变化和地下水埋深之间无显著相关性。研究结果有助于理解研究区地下水埋深变化条件下柽柳的径向生长状况。  相似文献   

7.
黑河下游地下水波动带地下水与植被动态耦合模拟   总被引:6,自引:0,他引:6  
采用对数正态分布模型,基于2006年黑河下游的野外实测数据,建立了研究区胡杨和柽柳植被盖度与地下水埋深的模型,并模拟了研究区的潜在植被.结果表明:黑河下游胡杨的最适宜地下水位和平均地下水位分别为2.6和3.6 m,柽柳则分别为2.0和3.0 m;胡杨的高盖度分布区主要集中在河道两侧的区域,而柽柳则可以在研究区的大部分区域以较高的盖度生存,对于研究区当前的地下水埋深而言,柽柳应该是最适宜生存的物种之一;研究区胡杨和柽柳的潜在植被空间分布与现状分布的相似性分别为43.4%和55.6%,导致相似程度不高的主要原因为土壤中存在的石膏盐盘层阻碍了土壤水分的垂直运动.  相似文献   

8.
间歇性生态输水塔里木河下游断面地下水位变化模拟   总被引:4,自引:0,他引:4  
地下水作为干旱区生态系统的重要组成部分,对植物生长具有重要作用。以塔里木河下游英苏断面2011—2015年逐月地下水埋深变化为研究内容,基于非稳定流理论,以河道附近水位边界条件作为初始求解条件,以余误差函数erfc(x)为求解函数,综合考虑地下水变化时间滞后效应及潜水蒸发作用,旨在构建间歇性输水河道地下水埋深变化模型。结果表明:(1)生态输水期间,在短期内,临近河道地下水埋深波动较大,而远离河道地下水埋深波动并未受到较大的影响,生态输水作用影响河岸附近地下水埋深变化存在一定时段的滞后期,且随着距离河道的增加,滞后期增长。(2)以河道为基点的地下水非稳定流运动及潜水蒸发作用是影响沿岸地下水变化的诸多环境因子中最敏感的因子。(3)模拟结果表明基于非稳定流理论对塔里木河下游地下水变化模拟效果较好,达到了地下水模拟精度的要求,对塔里木河下游断面尺度上地下水恢复状况研究及后期生态恢复评价具有重要的理论意义与参考价值。  相似文献   

9.
根据2014年在塔里木河下游5个断面30个植物样地的调查,获取了草本植物群落的特征资料,并记录了相应的地下水埋深数据。根据所收集的相关资料,对研究区内草本植物地上生态特征与地下水埋深间的关系进行了探讨。结果表明:1)随着离河道距离的加大,地下水位逐渐降低,草本植物群落生物多样性逐渐减小,盖度降低,结构趋于简单,地下水位6~7 m时草本分布十分稀少;2)地下水埋深与草本植物地上生物量以及地上含水率具有显著的相关性,随着地下水埋深的增加,草本植物的地上生物量逐渐减少,地上含水率也呈减少的趋势,但地上净初级生产力与地下水埋深的关系不明显;3)生态输水使距河道一定范围内地下水位升高明显,在纵向和横向上都表现出一定的规律,生态输水的影响范围逐渐加大,植被的响应也很显著,长势出现明显好转,多样性与盖度均有所增加。  相似文献   

10.
新疆塔里木河下游断流河道输水与生态恢复   总被引:36,自引:0,他引:36  
结合塔里木河下游输水过程中对9个地下水监测断面、18个植被样地的实地监测资料,分析了塔里木河下游输水条件下的浅层地下水位变化和天然植被的响应和恢复情况。研究结果表明,塔里木河下游输水有效地抬升了河道两侧的地下水位由输水前的6~8m抬升到了2~4m。在横向上,地下水位对输水的响应范围达到850m,胡杨和柽柳对地下水位变化的响应范围分别达到700和600m但对草本植物的影响范围较窄,林间沙地活化现象仍未得到遏制。提出为扩大输水的生态效应和加快受损生态系统的恢复重建,应在目前沿自然河道“线型”输水的基础上,分段实施河水漫溢的面上供水方案,并通过加强流域水管理、推广农业节水技术和加大河道整治力度等措施,来确保塔里木河下游一定的生态用水量。  相似文献   

11.
Intensive groundwater extraction causes many environmental problems globally. Reducing groundwater extraction is a primary method for alleviating these problems. However, this reduction may create new pollution issues because of an increase in groundwater vulnerability. A case study was done using the DRAOTIC evaluation method (an improved DRASTIC method for organic pollutant in aquifer vulnerability; soil (S factor) has been updated by organic matter (O factor) in the method) for the Hun River Basin, northeastern China, where groundwater intensive extraction had caused serious environmental and hydrogeological problems. The assessment results show that moderate vulnerability level is the main vulnerability level in the Hun River Basin; high vulnerability level and low vulnerability level categories occupy a smaller area; while very high and very low vulnerability categories occupy the smallest area. By combining the predicted groundwater level distribution and DRAOTIC model, the responses of groundwater vulnerability to different groundwater extraction reductions could be studied. The results show that groundwater vulnerability levels increased as groundwater extraction was reduced; this is because the rising groundwater levels make it easier for pollution coming from the surface to reach the aquifer. The more the reduction in groundwater extraction, the greater the increase in the area with higher vulnerability levels, and the greater the increase in pollution risk.  相似文献   

12.
A groundwater plume contaminated with gasoline constituents [mainly benzene, toluene, and xylenes (BTX)] had been treated by pumping and aeration for approximately 10 years, and the treatment strategy was recently changed to monitored natural attenuation (MNA). To gain information on the feasibility of using MNA to control the spread of BTX, chemical and microbiological parameters in groundwater samples obtained inside and outside the contaminated plume were measured over the course of 73 weeks. The depletion of electron acceptors (i.e., dissolved oxygen, nitrate, and sulfate) and increase of soluble iron were observed in the contaminated zone. Laboratory incubation tests revealed that groundwater obtained immediately outside the contaminated zone (the boundary zone) exhibited much higher potential for BTX degradation than those in the contaminated zone and in uncontaminated background zones. The boundary zone was a former contaminated area where BTX were no longer detected. Denaturing gradient gel electrophoresis (DGGE) analysis of polymerase chain reaction (PCR)-amplified bacterial 16S rRNA gene fragments revealed that DGGE profiles for groundwater samples obtained from the contaminated zone were clustered together and distinct from those from uncontaminated zones. In addition, unique bacterial rRNA types were observed in the boundary zone. These results indicate that the boundary zone in the contaminant plumes served as a natural barrier for preventing the BTX contamination from spreading out.  相似文献   

13.
Increasing demands of groundwater in petroleum-recovering regions could elevate the level and mobility of arsenic in groundwater as a result of the enhanced dissolution of arsenic-bearing iron or manganese oxide due to the accelerated sulfate reduction by microorganisms in a reductive environment. To substantiate this possibility, groundwater samples were collected from 220 water wells in the nearby petroleum wells in Kuitun. Dissolved arsenic, iron, manganese, and sulfate levels and pH in groundwater samples were analyzed. The dissolved arsenic levels in groundwater varied from <2.3 to 789.4 μg·L?1, in which approximately 96.4% of the measured values exceeded the allowed limits of the World Health Organization. An inverse relation existed between dissolved arsenic and sulfate levels. Most of the high arsenic-level samples (>300 μg·L?1) were found in wells at close proximity to petroleum wells where a high iron or manganese level was also detected. The oil-exploring activity in the study region seemed to have enhanced the microbial reduction of sulfate in underground environment and hence the level of arsenic in groundwater. The microbial sulfate reduction coupled with the reduction of arsenic-bearing iron oxides in the groundwater environment may explain the spatial heterogeneity of the arsenic level in groundwater.  相似文献   

14.
Submarine groundwater discharge in Osaka Bay, Japan   总被引:6,自引:0,他引:6  
Submarine groundwater discharge (SGD) rates in Osaka Bay were continuously measured and analyzed to evaluate seawater–groundwater interactions. Fast Fourier transfer and power spectrum density methods were applied to analyze the dominant periods of the SGD variations. Diurnal and semidiurnal periods of SGD variation were found, and they were caused by tidal effects. According to the separation of SGD into fresh and recirculated water components using automated seepage meter measurements and terrestrial groundwater flow analyses, the fresh groundwater component in SGD was evaluated to be in the range 4%–29% at Tannowa, Osaka. Therefore, SGD rates depend mainly on the volume of recirculated seawater. Correlation analyses between SGD and sea level show that SGD is delayed by 4h after sea level changes.  相似文献   

15.
van Liere  L.  Mur  L. R. 《Hydrobiologia》1982,91(1):511-518
An experimental system based on a continuous flow reactor is presented, in which undisturbed sediment cores can be investigated with regard to the release of phosphorus to the overlying water and the characteristics of the interstitial water. In this system the effect of simulated vertical groundwater movement was also studied. The results of three preliminary experiments are shown: 1) undisturbed core, 2) downward migration, 3) upward migration. The latter two experiments showed a rapid loss of phosphorus from the system in contrast to the first experiment. This process was reflected in the phosphorus concentration of the interstitial water.  相似文献   

16.
1. Reduced metabolic rate among cave organisms compared with surface species has long been suggested as an adaptation to food shortage in cave environments. However, comparisons of metabolic rates between species have not often included closely related surface and cave species. By measuring metabolic rate across three seasons and over a range of body sizes, we examined the hypothesis that the routine metabolic rate of Gammarus acherondytes, a federally listed stygobitic amphipod, is lower than that of the closely related stygophilic Gammarus troglophilus. To determine if human activities increased the supply of organic matter to caves, we also examined the relationship between residential development and bacterial contamination in water wells. 2. For G. acherondytes, the slope of the overall relationship between oxygen consumption and body dry mass did not differ from zero and did not vary seasonally, whereas for G. troglophilus it was positive and higher in summer than in winter and spring. These results provide insights into a potential novel metabolic adaptation among stygobites. Higher metabolic rate in young G. acherondytes would allow efficient use of typically transient energy sources and a low metabolic rate at larger body sizes would increase survival through periods of food scarcity. 3. The number of wells with faecal coliform contamination was weakly but positively correlated with the number of residential building permits, indicating that surface land‐use changes probably increase the availability of energy in groundwater systems inhabited by G. acherondytes. This may give stygophilic animals, with higher metabolic rates, a competitive advantage in the caves, thus reducing the abundance of stygobites such as G. acherondytes.  相似文献   

17.
A multidisciplinary study involving field geology, mineralogy and geochemistry of sediments and waters (surface and underground) and microbiology in two representative and juxtaposed areas having contrasting shallow aquifer conditions in West Bengal (India) has helped resolve the problem of high As-Fe incidence in Gangetic Delta and provided a new insight into the biogeochemical role of surface diatomaceous biomats (multilayered sheets of micro-organisms dominated by diatoms held together and bound to the moist substrate by secreted slimy extracellular polymeric substances) in groundwater purification. Regional geological investigation provides geoenvironmental clues to the development of profuse diatomaceous biomats (maiden report) selectively in clay-silt-rich moist geomorphic depressions (floodplains) conditioned by regular supply of nutrients, rain and flood waters and sunlight and unveils a correlation between the surface biomats and subsurface safe aquifers and vice versa. Lateral confinement and predominant monsoonal recharge pattern of the aquifers in this region restrict subsurface lateral saturation across the aquifers and allow maintenance of their respective geochemical status. This finding allows ready assessment of groundwater quality and helps develop a new bioengineering technique for improving groundwater conditions by growing artificial biomats. The present study provides the first natural evidence of arsenic groundwater purification through diatomaceous biomats.  相似文献   

18.
Groundwater pollution risk assessment is a useful tool to prevent and control groundwater pollution, but its quantitative research is still relatively immature. In this study, a geographic information system based LVF model for a semiquantitative assessment of groundwater pollution risk is established, based on the groundwater pollution source load (L), groundwater vulnerability (V), and groundwater function value (F). Further, the pollution source load is characterized by seven specific pollution sources, the vulnerability is calculated by the modified DRASTIC method, and the groundwater function value is evaluated with the water quality and quantity. The model was used to assess the risk of shallow groundwater pollution in Shenyang city, Northeast China, with an area of 8,263 km2. The results show that highest risk areas account for 16.3% of the study area and are mainly distributed in the east of the study area. High risk areas are significantly affected by a shallow buried depth of groundwater and many types of harmful pollutants from industrial, agricultural, and domestic pollution sources. The evaluation results reflect the risk of groundwater pollution in the Shenyang area, which is relevant to the management and sustainable use of groundwater resources in the area.  相似文献   

19.
朱丽  徐贵青  李彦  唐立松  牛子儒 《生态学报》2017,37(6):1912-1921
以3条样带上117块植被群落调查样方为基础资料,研究了海流兔河流域植被物种多样性及生物量与地下水位之间的关系。结果表明:1)地下水位高低及地貌类型均会影响草本层植物群落组成及优势种构成。滩地样地中,随地下水位降低,优势草本的更替方向为寸草,芨芨草,马蔺,狗尾草,碱茅;沙坡样地中,优势草本的更替方向为大针茅,沙鞭,沙蓬,沙打旺。2)地下水位为1.5 m时是草本植物群落生长发育最适宜区域,物种多样性及丰富度达到最大,而灌木层物种多样性及丰富度随地下水位下降呈现波动变化的特征;当地下水位埋深小于5.0 m时,草本层物种多样性及丰富度明显高于灌木层,在地下水位埋深大于5.0 m时,草本层物种多样性指数开始出现低于灌木层的现象。3)草本植物多样性及丰富度和生物量之间关联性不强,滩地样地中,草本层地上生物量及地下生物量在地下水位为1.8 m时具有最大值,但植物群落结构较为单一;沙坡样地中,地上生物量最大值出现在地下水位为5.0 m的区域内,而地下生物量最大值出现在地下水位为3.5 m时。综上,物种多样性、地上及地下生物量与地下水位都不是简单的线性关系,而是有一个最适水位;高于或低于这个最适水位,多样性和生物量都会下降。  相似文献   

20.
Summary The Gnangara Groundwater Mound, centred 38 km north of Perth, Western Australia, is a large, shallow unconfined aquifer that is currently under abstraction as part of the public metropolitan water supply. To investigate the impact of lowering groundwater levels on a Banksia woodland on the Mound, vegetation monitoring near a groundwater abstraction bore (known as P50) began 1 year before becoming operational. In February 1991, 2 years after abstraction commenced, extensive death of the Banksia overstorey was observed within close proximity of the bore, following a short period of high summer temperatures. The site was subsequently revisited and the understorey floristic composition, abundance and vigour of overstorey species resurveyed, and compared with data collected from a site under long‐term monitoring and not currently influenced by abstraction. A lowering of groundwater level by 2.2 m at P50 between the summers of 1990 and 1991, resulting from the cumulative effects of abstraction and below average annual rainfall (low groundwater recharge), coincided with a loss of between 20 and 80% of adults of overstorey species and up to 64% of adults of understorey species within 200 m of the bore. Over a similar time period no significant decreases in the abundance of overstorey or understorey species were recorded in the monitored site not influenced by groundwater abstraction. Of the overstorey species, Holly‐leaf Banksia (Banksia ilicifolia) displayed the greatest susceptibility and lowest net recovery following the abstraction event at P50. The negative impact of groundwater drawdown on Holly‐leaf Banksia populations makes this overstorey species an important indicator of decreasing groundwater levels on the Gnangara Groundwater Mound. Water stress may have been the primary cause of vegetation death in close proximity to the P50 bore, although this would have been exacerbated by extreme summer temperatures (> 45°C) recorded during February 1991. The P50 scenario represents a localized response to an acute drawdown event, in association with other environmental factors, and provides invaluable information on the assessment of groundwater abstraction and poor groundwater recharge events on a Banksia woodland community. However, there are limitations in using the community response at P50 to manage the impact of drawdown events on other plant communities occurring on sandy, shallow aquifers.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号