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1.
太湖人工生态系统中氮循环细菌分布   总被引:3,自引:3,他引:0       下载免费PDF全文
对太湖五里湖的以水生高等植物为主的湖泊人工生态系统,用最大可能数法,测定了该系统内各种生态类型水生高等植物群落内的4类氮循环细菌的分布。结果表明反硝化细菌的最大可能数,在水生高等植物群落内水体中较敞水区湖水高2-5个数量级差异极显著;漂服植物各落内水体的反硝化细菌MPN值较沉水和浮叶植物群落内水体高2-3个数量级,差异极显著;  相似文献   

2.
太湖水体中碱性磷酸酶的作用阈值   总被引:23,自引:6,他引:17  
高光  高锡芸  秦伯强  季江 《湖泊科学》2000,12(4):353-358
对不同PO^3-4-P浓度下,不同粒级组分中碱性磷酸酶活性的分布及其变动规律的研究表明:(1)随着水体中PO^3-4-P浓度的增加,水体中总碱性磷酸酶活性(TAPA)相应的减少(r=-0.586,n=55),水体中的TAPA增值,在PO^3-4-P浓度范围为0-0.010mg.L^-1,无显著差异;而当PO^ 3-4-P浓度〉0.010mg.L^-1时,差异极显著(P〈0.01),(2)水体中的碱  相似文献   

3.
淀山湖水生维管束植物群落研究   总被引:15,自引:1,他引:15  
由文辉 《湖泊科学》1994,6(4):317-324
论述了淀山湖水生维管束植物的种类组成、分布、群落类型、群落的数量特征及演替。结果是:(1)湖中分布有26种水生维管束植物,隶属16科,21属;其优势种为苦草、菹草、马来眼子菜、芦苇等。(2)湖中水生植被呈不规则环带状分布,并可划分为挺水、浮叶、沉水三个植物带,12个主要水生维管束植物群落。(3)水生维管束植物的重要值以苦草最大,茨藻属植物最小。(4)淀山湖水生维管束植物群落有由沉水型向浮叶型、挺水型或漂浮型过渡的趋势。  相似文献   

4.
研究高原湖泊沉积物和水体细菌群落结构的差异对于水生态治理与保护具有重要的科学意义。本文选取青藏高原中东部共19个湖泊为研究对象,采集沉积物和水体样本,使用高通量测序技术和统计分析,解析湖泊沉积物和水体细菌群落结构、空间分布特征、共发生网络模式、群落构建过程的差异及其原因。研究结果表明沉积物细菌群落alpha多样性指数(Chao1指数、Shannon多样性指数、Faith’s系统发育指数和Pielou均匀度指数)均显著高于水体细菌群落。沉积物和水体细菌的优势门均为Proteobacteria(相对丰度为45.33%和41.77%),而水体细菌群落结构具有较强的空间异质性。主坐标分析和相似性分析结果表明沉积物和水体中细菌群落结构差异极显著,海拔和纬度分别是青藏高原湖泊沉积物和水体细菌群落结构变化最显著的驱动因子。沉积物和水体细菌群落均具有明显的距离衰减模式,而沉积物细菌比水体细菌群落在空间上的周转率小。采样湖泊沉积物细菌群落共发生网络复杂度和稳定性高于水体细菌。沉积物和水体细菌群落的平均归一化随机率值分别为0.24和0.72,表明确定性过程在沉积物细菌群落构建的过程中起到了重要的作用,而水...  相似文献   

5.
由腾冲火山区数字地震资料研究火山区的应力场   总被引:1,自引:0,他引:1  
根据Brune(1970)地震震源破裂模式,导出了地面运动峰值速度参数(r.v)与应力降△σ或环境应力O值的依赖关系。利用腾冲火山地震数字化记录观测的峰值速度资料,研究了火山地区的应力降△σ和环境应力O值。结果给出,火山地区的应力降△σ多数在0.2~2.0MPa之间,平均为0.95MPa;环境应力O值在0.7~3.0MPa之间,平均为2.2MPa,属于低应力地区。值得注意的是在最年轻的打鹰山-马鞍册火  相似文献   

6.
固定化土著氮循环细菌在城市湖泊水体净化中的应用   总被引:2,自引:1,他引:1  
从镇江金山湖天然水体中筛选分离出土著氨化、亚硝化、硝化和反硝化细菌,对氮循环细菌固定化后在镇江金山湖示范工程区进行水体净化应用.结果表明,运行一段时间后水质得到明显改善,氨氮、亚硝酸盐氮和硝酸盐氮以及总氮浓度处于动态变化中,有降低的趋势;氨氮含量已经达到Ⅱ类指标,总氮和COD分别达到Ⅴ类、Ⅲ类指标;分析结果还显示硝酸盐氮是金山湖水体中总氮的主要存在形式,与水体荒漠化状态有关;固定化氮循环细菌通过扩散,可以增加水体及植物根区的微生物数量,高出对比组1-3个数量级;固定化氮循环细菌技术对荒漠化水体氨氮、总氮和COD去除具有重要意义.  相似文献   

7.
本文使用滇西地震实验场区近场微震观测中的洱源、脉地、松挂地区的三次微震序列资料,研究了地面运动峰值速度vm与地震矩M0和环境应力τ0的关系,利用vm∝M01/3τ04/3的关系,估算了这三次微震序列的环境应力参数τ0值和应力降△σ。结果认为,地面运动峰值速度参数(v·r)是环境应力参数τ0或△σ的函数,且τ0或△σ与地震构造背景及介质状态相关,表现为处于不同构造背景的三次微震群测定的τ0和△σ值存在明显的差异。脉地震群为高应力序列,应力参数在(0.5~5.0)MPa,松桂震群为中等应力序列,在(0.3~1.5)MPa;洱源震群为低应力序列,在(0.01~0.5)MPa。由此而讨论了不同构造背景与环境应力参数的依赖性及其前兆意义。  相似文献   

8.
由速度谱测定微震的地震矩   总被引:2,自引:0,他引:2  
本文根据K.Aki(1980)提出的ω平方、常应力参数谱衰减模式.研究了地面运动速度谱衰减的带宽效应,导出了用速度谱直接估算地震矩M0的新方法。利用中日合作在滇西地震预报实验场区的洱源、脉地、松桂三个地区新获得的三次微震群序列数字化记录资料,通过不同参数Q值和△σ值的计算比较,选取Q=300,△σ=1.0MPa作为测定的参数值,计算了P波和S波速度谱的理论量板,并且与实际观测点的低频速度谱值相比较,用这样的方法测定了三次震群序列的地震矩M0和震源参数。结果给出,在震级为1.0~2.5级的范围内,地震矩M0=10(10)~10(13)(N·m),震源破裂半径a=70~200(m),P波和S波的拐角频率比f(op)/f(os)=1.58。用P波或S波三分量的速度谱值测定的地震矩比较一致,以及在相同震级范围内,用速度谱方法测定的结果与其它方法测定的结果也基本一致。本文提出的速度谱测地震矩的方法是一种简便实用的方法,当地震矩和观测低频谱值(如f=1.0HZ)已知时,可通过查函数表值快速测定M0值。  相似文献   

9.
孕震层断层面上摩擦系数的选取讨论拜尔利对高压岩石摩擦资料的分析,提出了岩石沿某一滑动面发生摩擦滑动的条件是:该面上的正应力σ与剪应力τ满足下列关系:τ=0.85σ(σ<200MP_α)τ=500MP_α+0.6σ(σ≥200MP_α)式中σ、τ的单位...  相似文献   

10.
微生物是湖泊生态系统重要的有机组分。了解不同时期青藏高原湖泊细菌群落特征、环境驱动因子及其群落构建过程的差异,对高原湖泊水生态管理具有重要的指导意义。分别于2020年6和12月采集青藏高原东北部5个湖泊水样,基于高通量测序技术、统计分析和模型分析,解析高原湖泊群在非冰封期和冰封期细菌群落结构、环境驱动因子和中性过程、确定性过程以及随机性过程在细菌群落构建过程的贡献。结果表明:(1)非冰封期湖泊细菌群落的Chao1丰度指数、Simpson和Shannon多样性指数低于冰封期,Spearman相关性分析结果表明非冰封期细菌群落的Chao1丰度指数和多样性指数与水温和海拔显著相关,而冰封期细菌群落的Chao1指数和多样性指数与总氮显著相关;(2)水体细菌群落的优势门均为变形菌门(Proteobacteria),非冰封期细菌中拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)和厚壁菌门(Firmicutes)的平均相对丰度明显高于冰封期。另外,主坐标分析和相似性分析结果表明非冰封期和冰封期的细菌群落组成差异极显著;(3)冗余分析结果表明不同时期湖泊群细菌群落结构的...  相似文献   

11.
采用最大可能数法对平原河网地区不同氮污染程度河道水体中浮游、颗粒附着及底泥中的氨化、亚硝化、硝化和反硝化菌进行测定,研究水体氮污染程度对氮循环菌不同种群的影响效应及其分布特征.结果表明,浮游、颗粒附着和底泥中亚硝化菌的丰度随着水体氮污染程度的增加而升高,但不同氮污染程度下氮循环菌种群结构组成之间差异不大,而浮游、颗粒附着及底泥生活类型之间的氮循环菌种群结构组成存在较大差异,其中浮游与底泥中氮循环菌种群组成结构之间差异最大.在氮污染水体中,浮游、颗粒附着和底泥氮循环菌中均以氨化菌为优势种群,显著高出其他氮循环菌种群多个数量级,而亚硝化菌和硝化菌丰度相对较低,反硝化菌在水体悬浮颗粒物上存在相对较高的丰度,不同氮循环菌种群组成比例存在失衡现象.  相似文献   

12.
利用从镇江金山湖天然水体中筛选分离出的土著氨化、亚硝化、硝化和反硝化细菌,将氮循环细菌固定化后在金山湖示范工程区进行水体脱氮净化效果研究.结果表明,运行一段时间后水质明显得到改善,氨氮、亚硝酸盐氮、硝酸盐氮以及总氮浓度均显著下降,氨氮浓度指标达到国家水质Ⅰ类标准,总氮浓度指标达到水质Ⅱ类标准.同时,对湖泊水体的N_2O气体排放通量进行了检测,结果显示,随着实验的进行,金山湖区的N_2O气体排放通量逐渐升高,4月份的平均值为23,51μg/(m~2·h)、5月份的平均值为29.52μg/(m~2·h)、6月份的平均值为59.10μg/(m~2·h).水质氮素指标以及N_2O气体排放通量数据说明利用微生物固定化载体强化净化技术对城市湖泊水质净化具有显著效果和重要意义.  相似文献   

13.
Secondary drainage canals have the potential to effectively mitigate excess nitrogen loads from diffuse and point sources. In vegetated (Phragmites australis and Typha latifolia) and in unvegetated canals subjected to diffuse and point pollution, nitrogen removal was evaluated by means of simple in–out mass balance and potential uptake by macrophytes was estimated from biomass data. Results suggest an elevated control of nitrogen in vegetated ditches receiving point source of pollution (average abatement of 50% of the total N load per linear km), whereas removal processes are much less effective in unvegetated ditches. The comparison between net abatement and plant uptake, highlights the presence of other unaccounted for processes responsible for a relevant percentage of total N removal. Overall, results from this study suggest the importance of actions aiming at the appropriate management of emergent vegetation, in order to improve its direct and indirect metabolic functions and maximize nitrogen removal in impacted watersheds.  相似文献   

14.
潜流湿地中微生物对三峡库区微污染水净化效果的影响   总被引:2,自引:1,他引:1  
刘明  黄磊  高旭  马晓霞  杜刚 《湖泊科学》2012,24(5):687-692
为了探讨潜流湿地对三峡库区微污染河水的净化效果,在野外构建芦竹、菖蒲、空心菜和无植物(空白)水平潜流人工湿地,研究人工湿地系统中微生物基本菌群和功能菌群数量分布,探讨污染物去除与微生物菌群种类和数量的相关性.结果表明:实验湿地系统运行情况良好,植物湿地系统对各污染物指标的去除效果优于空白湿地系统;芦竹、菖蒲、空心菜和空白湿地系统的微生物数量均随温度的降低而减少,其中,植物湿地系统的微生物数量高于空白系统;各湿地系统的微生物数量与水质指标去除率之间的相关性较强,在夏季,不同人工湿地系统的细菌总数与CODMn的去除率之间存在着显著的正相关,真菌、亚硝酸细菌总数与铵氮去除率之间均存在着显著的正相关,在冬季,不同人工湿地系统的反硝化细菌总数与总氮去除率之间存在着显著的正相关.  相似文献   

15.
We compare the environmental characteristics and bacterial communities associated with two rushes, Juncus maritimus and Bolboschoenus maritimus, and adjacent unvegetated habitat in a salt marsh subjected to historical mercury pollution. Mercury content was higher in vegetated than unvegetated habitat and increased with sampling depth. There was also a significant relationship between mercury concentration and bacterial composition. Habitat (Juncus, Bolboschoenus or unvegetated), sample depth, and the interaction between both, however, explained most of the variation in composition (~70%). Variation in composition with depth was most prominent for the unvegetated habitat, followed by Juncus, but more constrained for Bolboschoenus habitat. This constraint may be indicative of a strong plant-microbe ecophysiological adaptation. Vegetated habitat contained distinct bacterial communities associated with higher potential activity of aminopeptidase, β-glucosidase and arylsulphatase and incorporation rates of (14)C-glucose and (14)C-acetate. Communities in unvegetated habitat were, in contrast, associated with both higher pH and proportion of sulphate reducing bacteria.  相似文献   

16.
This study combined bacterial incubation and hydrogeochemical methods to investigate denitrification in the surface water, top soil (0–20 cm), and shallow groundwater of the Ochi wetland in Japan. Surface water was rich in nitrate (40 mg/l) and denitrifying bacteria (700 per ml). Three functional zones in the wetland were identified in the top soil and shallow groundwater. In the upstream portion of the wetland (Zone I), the counts of denitrifying bacteria in top soil increased from 5200 to 14 970 per ml and nitrate decreased from 25·4 to 1·8 mg/l. Organic carbon concentrations decreased as sulfate increased from 4·0 to 9·6 mg/l in this zone. In the middle‐stream of the wetland (Zone II), all concentrations of major anions, iron, organic carbon, and total nitrogen content in top soil were relatively constant, but the counts of denitrifying bacteria increased up to 70 200 per ml. In the downstream portion of the wetland (Zone III), complete removal of nitrate resulted in sharp reduction of counts of denitrifying bacteria. Correspondingly, dissolved oxygen (DO), organic carbon, and total nitrogen increased in this zone. Counts of denitrifying bacteria were lower in shallow groundwater than in top soil; nitrate concentrations in shallow groundwater were also very low in this zone. DO and the oxidation/reduction potential data suggest that groundwater flows to the surface along an extended flow path, thus providing nitrate for the denitrifying community. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

17.
《水文科学杂志》2013,58(2):316-326
Abstract

Nitrate contamination in groundwater originates mainly from excessive use of fertilizers and uncontrolled discharge to land of incompletely-treated wastewater associated with agricultural activities. A systematic field investigation was carried out in a sub-catchment of Dianchi Lake, Kunming, Yunnan, China, into the hydrological, biological and geological processes of nitrogen transport and transformation in the aeration zone and aquifer system. In situ experiments showed that the quantity of NO3-N recharged into groundwater was related to fertilization. Nitrification and denitrification behaved quite differently but were affected by moisture content and Eh value. The vertical infiltration rate was controlled by the groundwater table and hydraulic conductivity of the soil. The existence of a zero-flux plane reflected the dynamics of water fluxes in the soil profile and Eh was measured in the aeration zone. In response to these factors, the nitrification rate was greatest in the top soil and reduced with the depth of soil; it was 6.53 mg/(kg·h) in the vegetated plot and 0.2–0.3 mg/(kg·h) in the unvegetated one. The denitrification rate in the unvegetated plot was 6.36 mg/(kg·h), and it was 2.79 mg/(kg·h) in the vegetated one.  相似文献   

18.
Ground retreat was monitored on two vegetated and two unvegetated profiles over a five-year period. The average annual retreat of the two unvegetated profiles was 5.84 mm and 3.62 mm; that of the two vegetated profiles 2.34 mm and 2.07 mm. Slope evolution was controlled by the mid-slope-ward migration of two zones of accelerated erosion and the resulting replacement of a central rectilinear slope segment by the upper and lower slope elements.  相似文献   

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