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1.
基于16S rRNA和18S rRNA高通量测序技术,研究了长江南京段21条主要入江支流不同水期底质多营养级微生物的群落结构特征,利用Shannon指数等分析了样品中微生物群落的多样性。结果表明,42个样品的细菌群落归属于285个纲水平上的OTUs (operational taxonomic units),归属于62个门;优势菌门为变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)等,优势菌纲为β-变形菌纲、α-变形菌纲、δ-变形菌纲等。原生动物中的优势类群为不等鞭毛类(Heterknta)、囊泡虫类(Alveolata)和绿色植物(Chloroplastida),后生动物中的优势类群为节肢动物(Arthropoda)、轮虫(Rotifera)和线虫(Nematoda)。平水期底质的细菌、原生及后生动物的多样性相对较低,入江支流的水生态系统相对不稳定,尤其是金川河、七里河等。  相似文献   

2.
阿勒泰小克兰河上游植物群落的垂直分布格局及环境分析   总被引:1,自引:0,他引:1  
通过对阿勒泰小克兰河上游的植被调查,并运用植物多样性指数计算及冗余分析,探究植物随海拔梯度的变化规律。结果表明:在各海拔梯度内优质牧草均占优势地位,在海拔1 050 m~1 450 m和2 150 m~2 550 m分布着草本群落,1 450 m~2 150 m乔、灌、草均有分布;随着海拔上升,Simpson、Shannon-Wiener多样性指数单调微增,Simpson优势度指数单调递减,Bray-Curtis指数和Margalef指数呈单峰分布,Pielou指数、S-Φrenson指数、Morisita-Hom指数呈"U"型变化;冗余分析发现海拔、坡向是影响植物群落组成及分布的主要因子。  相似文献   

3.
湖泊微生物生态过程研究是深入了解湖泊生态系统结构与功能的关键。论述了湖泊微生物多样性时空分布规律及群落构建机制研究进展,总结了微生物群落构建机制的分析方法,介绍了微生物生态网络构建原理及应用。群落构建机制分析方法分为统计分析法、模型推断法和生态网络分析法。统计分析法包括群落结构差异分析、群落结构-环境因子关联分析和方差分解分析等,此类方法能够初步识别驱动群落组成与结构时空差异的影响因子,判别空间因素与已知环境变量对群落构建过程的相对贡献;模型推断法包括中性群落模型方法和零模型方法等,能够进一步实现对群落构建生态过程的区分,量化和比较随机性因素及确定性因素的相对重要性;生态网络分析法可用于揭示物种共现模式,探究作为确定性因素的生物相互作用,也可用于物种-环境响应关系的研究,探究环境选择过程对群落结构的影响。  相似文献   

4.
浙江北部海域春季浮游动物的群落结构研究   总被引:2,自引:0,他引:2  
根据2007年春季在浙江北部海域所采集的浮游动物样品,对该调查海域浮游动物的种类组成、丰度、生物量和生物多样性进行了探讨,采用多元统计软件PRIMER 5分析了该海域浮游动物的群落结构。研究结果表明,调查海域共鉴定各类浮游动物62种、浮游幼虫12种,合计74种。经统计共有2种优势种,分别是中华哲水蚤(Calanus sinicus)和五角水母(Muggiaea atlantica)。浮游动物生物量和丰度的平面分布比较相似,主要分布在调查海域的东部和东南部,并存在着向东南方向呈递增的趋势,而在杭州湾内的值比较小。调查海域浮游动物生物多样性比较低,平均值为1.54。根据对本次调查获得的浮游动物群落结构的聚类分析,主要存在着两个生态类群,群落Ⅰ为沿岸低盐群落,群落Ⅱ为暖温带近海群落。  相似文献   

5.
陆源有机污染对舟山海域大型底栖生物分布的影响   总被引:2,自引:1,他引:1  
2009年4月对舟山海域进行了25个站位的底栖生物调查,结合同期进行初级生产力、海水水质等的调查数据,分析了初级生产力、富营养化等环境因子对舟山海域大型底栖生物分布的影响。结果表明,舟山海域大型底栖生物共获得84种,多毛类是主要优势类群。舟山海域大型底栖生物平均生物量为11.62g/m2,平均丰度为208.5个/平方米,多样性指数(H')为1.64。舟山海域大型底栖生物的生物量、丰度和多样性指数均呈现由近岸向外海递增的趋势。应用相关性统计分析表明,舟山海域大型底栖生物的分布与海水化学耗氧量(COD)、无机氮(DIN)、磷酸盐(DIP)、富营养化指数和底层溶解氧(DO)存在显著负相关;与初级生产力、盐度和透明度存在显著正相关。说明陆源有机污染、盐度、透明度、初级生产力和底层溶解氧是影响舟山海域大型底栖生物分布的主要因素,其中陆源有机污染是最主要的影响因素。  相似文献   

6.
为了解淮河干流江苏段着生藻类群落结构时空变化特征及其与环境因子的关系,于2020年11月—2021年7月分4个季节布设5个断面采样调查。结果表明:该河段共检出着生藻类5门36属39种,物种组成以硅藻、绿藻和蓝藻为主,占比分别为35.90%、33.33%和23.08%;着生藻类群落结构虽然在空间上未出现显著差异,但呈现秋季>冬季>春季>夏季的季节变化趋势;alpha多样性指数和beta多样性距离分析均显示,着生藻类群落变化主要体现在季节差异上,夏季和冬季较春季和秋季变异程度更高;环境因子冗余分析(dbRDA)表明,影响着生藻类群落结构在不同季节之间演替的环境因子各不相同,总氮是营养盐指标中唯一显著的影响因子。  相似文献   

7.
鄱阳湖浮游藻类群落特征及与环境因子典范对应分析   总被引:1,自引:0,他引:1  
通过2018—2019年夏冬季在鄱阳湖布设17个采样点,采样检测浮游藻类和水质参数,并采用典范对应分析法研究该湖浮游藻类群落结构特征及其与环境因子的相互关系。结果表明,两次调查共检测出浮游藻类7门31科58属,浮游藻类丰度范围为3.5×105 L-1~1.15×107 L-1,主要由绿藻门、硅藻门和蓝藻门组成,绿藻门为夏、冬季主要优势种群。典范对应分析结果显示,鄱阳湖冬季湖区水环境空间差异较大,而夏季差异较小;夏季氮磷营养盐和DO是影响浮游藻类群落时空分布的主要环境因子,冬季氮磷营养盐、BOD5和IMn是影响浮游藻类群落时空分布的主要环境因子。  相似文献   

8.
2009年4月对长江口及其邻近海域的21个站位进行了大型底栖生物调查,分析了大型底栖动物的环境质量状况,并结合环境因子数据进行了典范对应分析。结果表明,调查共鉴定大型底栖生物56种,多毛类为主要类群。平均生物量为11.26 g/m2,平均丰度为237.4个/m2。生物量、丰度均呈现由近岸向外海递增的趋势。水深、盐度、初级生产力和有机质、重金属是影响调查海域大型底栖生物群落的主要环境因子。大型底栖生物的分布呈现出对有机污染与重金属污染显著的躲避趋势,表明有机污染与重金属污染已显著影响该海域大型底栖生物的生长。而小头虫、寡节甘吻沙蚕、长手沙蚕和丝鳃虫对有机污染和重金属污染展现出较强的的耐受性。  相似文献   

9.
连云港港区海洋环境质量状况   总被引:1,自引:0,他引:1  
为分析连云港海洋环境质量,对连云港港区水质、沉积物及生物因子进行监测。结果表明,港区内某些点位水质中无机氮含量较高,达到污染程度,其余点位监测指标均正常,沉积物中的重金属尚未对该海域造成污染。浮游植物31种,其中甲藻门8种,硅藻门23种,浮游植物数量变动为1.84×104m-3~1.16×105m-3;底栖生物17种,多样性指数平均值为1.89。港区内水域环境时空变化表明,海水中锌含量连续大幅增加,其余指标均下降50%,沉积物重金属含量变化不大。  相似文献   

10.
养马岛后海区域秋季大型底栖动物群落特征   总被引:2,自引:0,他引:2  
2010年9月在烟台养马岛后海海域开展了大型底栖动物调查,并进行了群落特征分析。结果表明,该海域内的大型底栖动物多毛类占绝对优势,群落间差异较小,可划分为4 个群落,长叶索沙蚕(Lumbrinereis longiforlia)、钩毛虫(Sigambra sp.)、中蚓虫(Mediomastus sp.)等多毛类生物的丰度高低是构成群落差异的主要因素。栖息环境的差异是造成群落间差异的主要原因,Shannon-Wiener多样性指数为1.17~2.92,平均值为2.13。人为扰动是影响多样性水平的主要因素,在航道通过、养殖区分布的影响下,群落受到不同程度的扰动,整体稳定性较弱。  相似文献   

11.
The aim of the study was to determine the extent of heavy metal pollution in the vicinity of a lead battery manufacturing plant in the Czech Republic, both in the general environment and within homes. Topsoils (0–5 cm) were sampled from 100 sites along 4 transects which crossed the battery factory, the town centre and outlying rural areas. Housedust samples were collected from 15 plant-workers' homes and 15 non plant-workers' homes located at various distances from the factory. Samples were analysed for levels of Pb, Zn, Cd, Cu, As and Sb, using ICP-AES. Soil concentrations of Pb, Cd, As and Sb peaked at the perimeter fence of the battery factory with Pb levels of up to 12 650 g g> -1. Concentrations of these metals decreased exponentially within 500 m of the plant. Whilst the battery factory does appear to be a source of all the metals with the exception of Zn, emissions do not appear to be transported to any great extent over distances of more than 0.5 km. Topsoil and housedust concentrations of Pb, Zn, Cd, Cu, As and Sb in the general Mlada Boleslav area do not appear to be significantly different from those recorded in a large scale survey of urban soils in the United Kingdom. A comparison of housedust Pb concentrations in homes of plant workers and non-plant workers suggests that there may be a small input of Pb into the home environment by battery plant employees.  相似文献   

12.
微波消解-原子吸收光度法测定土壤中铜锌铅镉镍铬   总被引:25,自引:5,他引:25       下载免费PDF全文
用微波消解-原子吸收光度法测定土壤中铜,锌,铅,镉,镍和铬。通过硝酸-氢氟酸-过氧化氢体系消解液对土壤样品消解,选择出微波最佳消解条件。对硝酸-盐酸-过氧化氢体系消解液和硝酸-氢氟酸-过氧化氢体系消解液进行消解对比试验,发现前者不能将土壤样品完全消解,后者能将样品消解完全,但需将消解液中剩余的酸赶尽,否则测定结果将明显偏低。微波消解土壤与传统电热消解相比,操作简便快速,可提高工作效率。  相似文献   

13.
The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.  相似文献   

14.
A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g-1 wet weight (ww), PCBs 0.69 g g-1, 2,3,7,8-TCDD 2.3 ng kg-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.  相似文献   

15.
The draft of the German guideline to calculate automobile exhaust dispersion is explained. It contains a two-stage-system: For first quick estimates the guideline contains the simple models MLuS and STREET. In case these models are not applicable or their results shows concentration levels close to the air quality standards, the more complex models PROKAS_V and MISKAM are recommended. PROKAS_V is a Gaussian plume model, MISKAM is a 3-dimensional microscale non hydrostatic flow model for built-up areas with an Eulerian dispersion model. The guideline comprises cases in rural areas without or with few adjacent buildings as well as urban areas with buildings near the roads. The contribution gives information about the models, typical results and some of the problems showing up presently.  相似文献   

16.
The population counts of hydrocarbon-utilising yeasts weremonitored at six sampling stations in the Benin City municipalarea over a four-week period. Although the population countswere relatively constant in each locality, the highest countsoccurred in areas heavily polluted by domestic and industrialeffluents. A total of thirty-five hydrocarbon-degrading yeastswere isolated from soil at the sampling stations usingn-hexadecane as sole carbon source. The isolates were identifiedas belonging to the genera Candida (27 strains), Endomycopsis (4 strains). All the organisms grew on long-chainn-alkane, kerosene, diesel oil and crude oil but failed to growon short-chain n-alkane, aromatic and alicyclic hydrocarbons.Measurement of growth attributes of the isolates usingn-hexadecane, diesel oil and crude oil as substrates showed thatthe Candida species were better utilizers of hydrocarbonsubstrates relative to Endomycopsis and Schizosaccharomyces species.  相似文献   

17.
This paper gives mathematical details and sample applications of SWAGMAN Farm (SWAGMAN, Salt Water and Groundwater Management), a farm-scale hydrologic economic model that integrates agronomic, climatic, irrigation, hydrogeological and economic aspects of irrigated agriculture. The model is capable of determining optimum mix of land use to keep watertable and soil salinity within acceptable limits while maximising the economic returns. Alternatively, the model can simulate water and salt balance and economics of a given cropping preference. Web-based and Geographic Information Systems versions of the model are available for integration with the environmental reporting systems of the irrigation areas.  相似文献   

18.
用火焰原子吸收光谱法测定了苏州开发区26种蔬菜中的铜、锌、铁、锰和镍的含量。蔬菜样品用硝酸高氯酸混合酸进行消解。4次测定值的相对标准差<5%,加标回收率在92%~107%之间。26种蔬菜中铜、锌、铁、锰、镍的含量基本均在世贸组织规定的范围内。  相似文献   

19.
Using Multiple Taxonomic Groups to Index the Ecological Condition of Lakes   总被引:6,自引:0,他引:6  
Biological indicators of communitiestypically reflect a common environmental signalreflecting the general condition of the ecosystem, as well asindividual signals by indicators differentiallysensitive to particular environmental conditions. Wedescribe here a method of integrating and interpretingsuch indicators from 19 New England lakes for fivetaxonomic groups (diatoms, benthos, zooplankton, fish,and birds). Our approach provides a systematicstandardized way to integrate multiple metrics fromdifferent taxonomic groups by addressing four elementscrucial to analyzing data from multiple indicators: covariate control, re-scaling of data, standardizing the sign of responses, and dimensional reduction. We evaluated the biologicalmetrics against individual environmental stressors andagainst multivariate physicochemical metricscharacterizing general anthropogenic stress among thelakes. The method detected a response to variationin the gross environmental condition of the lakes thatwas correlated across taxa and metrics. In addition,a differential response to near shore conditions wasdemonstrated for fish. The success of the approach inthis study lends support to its general application toecological monitoring involving complex data sets.  相似文献   

20.
We determined concentrations of selected trace elements inlivers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from the eastern Canadianarctic during 1997 and 1998. Concentrations of totalmercury and organic mercury were generally low in the liversof these birds (less than 6 and 4 g g–1 dry wt,respectively). Selenium ranged between 11–47 g g–1 inlivers. Renal cadmium concentrations were among the highestever published for this species (range: 47–281 g g–1). The regressions of log-transformed concentrations ofthese trace elements in blood samples on those in liver orkidney were significant (all P-values < 0.05) andpositive. However, except for organic mercury (RM 2 = 0.83), the co-efficients of determination were low tomoderate (range of R 2: 0.26–0.52), suggesting poorto moderate predictive capability. Furthermore, therelationships between total mercury in blood and liverchanged between 1997 and 1998, suggesting that it would notbe possible to predict consistently, concentrations ofmercury in blood from those in liver based on samples takenin one year. Blood samples can be used to determineconcentrations of these trace elements in common eiders (andprobably other sea duck species as well). The use of bloodsamples is especially warranted when it is undesirable tokill the animal such as when working with rare or endangeredsea duck species or when the objective is to relate traceelement exposure to annual survival rates. However, thepredictive equations developed here should not be used topredict expected concentrations in one type of tissue fromthose in the other.  相似文献   

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