共查询到19条相似文献，搜索用时 140 毫秒
1.
蓝藻水华暴发前,浮游植物群类结构的变化可通过其指示型色素的浓度变化来反映.为了同时反演叶绿素a、叶绿素b(绿藻门指示型色素)、叶绿素c(硅藻门指示型色素)和藻蓝素(蓝藻门的指示型色素)的浓度,利用偏最小二乘回归构建线性模型,通过2011年太湖实测吸收数据,较为准确地反演了叶绿素a和藻蓝素的浓度;针对无明显优势藻的春季数据集较为准确地反演了叶绿素b和叶绿素c的浓度.相对于经典最小二乘算法,偏最小二乘法在多色素混合的吸收光谱分析上更为有效.通过反演指示性色素浓度来反映藻类的分布,为富营养化湖泊主要藻类时空分布变化的遥感监测提供了一定的理论与技术支持. 相似文献
2.
山东某新建水库浮游藻类的群落结构特征及其环境驱动因子 总被引：2，自引：1，他引：1
基于山东某新建水库中2014年4月-2017年12月的浮游藻类和水质监测结果，研究了藻类群落结构特征，采用非度量多维尺度分析了各年份不同季节藻类群落结构的相似性，利用冗余分析探究了藻类群落结构和环境因子的关系.结果表明：尖针杆藻（Synedra acus）、湖泊伪鱼腥藻（Pseudanabaena limnetica）和小球藻（Chlorella vulgaris）为此水库的主要优势藻种.水库藻类群落结构的季节演替不稳定，冬、春季多以硅藻和绿藻占优势，不同年份夏、秋季藻类结构差异较大，蓝藻和硅藻在夏、秋季存在一定的竞争优势.该水库于2013年底开始启用，由于水体环境的波动，藻类群落结构有所变化，整体上是由蓝藻-绿藻-硅藻向硅藻-绿藻-蓝藻变化.水库浮游藻类生长主要受到氮盐和高锰酸盐指数影响，但不同年份的主要环境影响因子存在一定差异. 相似文献
3.
藻蓝蛋白与叶绿素a作为特征色素常用于表征蓝藻的生物量.藻蓝蛋白与叶绿素a通常用荧光光谱或原位荧光强度检测,但是在实际水体中藻蓝蛋白与叶绿素a的荧光效应相互干扰会影响测量精度,极大限制了该方法的应用.本文根据朗伯比尔定律,利用二阶矩阵模型设计了一套在荧光检测过程中"激发光-发射光"优化抗干扰的波长选择方法,并利用多元线性回归分析建立了两种色素浓度与荧光强度之间的多元校正线性模型,实验验证了所筛选蓝藻荧光分析法中特定激发光和发射光波长的有效性.本研究实现了两种色素检测过程中的成功解耦,可在藻蓝蛋白的原位检测中排除水体中藻蓝蛋白与叶绿素a之间的相互干扰,提高藻蓝蛋白和叶绿素a的原位检测精度,为开发便携式蓝藻检测传感器时的波长选择提供理论基础. 相似文献
4.
太湖越冬蓝藻空间分布的初步研究 总被引：5，自引：1，他引：4
为确定2007-2008年冬季蓝藻在太湖各个湖区的分布及其变化规律,在冬季逐月对太湖主要湖区14个位点采集底泥和水样,应用荧光分析法测定样品中藻蓝素含量,以确定冬季太湖各个湖区的藻蓝素分布状况,比较冬季太湖各个湖区水体和底泥中蓝藻的分布差异.实验结果说明与夏季情况不同,相对于西南太湖水域,2007-2008年冬季北太湖水体和底泥中的蓝藻含量均较低,而西南湖区部分区域12月仍出现了蓝藻的聚集,底泥表面的藻蓝素含量也较高,说明调查期间,冬季越冬蓝藻主要分布于西太湖和南太湖. 相似文献
5.
太湖底泥水华蓝藻复苏的模拟 总被引：13，自引：5，他引：8
本实验采集太湖梅梁湾底泥及上覆水,在保持底泥表面完整的前提下在实验室中建立湖泊生态系统模拟装置,探索太湖底泥中蓝藻种群的复苏规律经60d光照升温培养,显微观察蓝藻复苏细胞,测定底泥和上覆水中的色素含量.结果表明,在室内模拟条件下,太湖底泥蓝藻复苏初始时主要以2-8个细胞的小群体存在,其细胞直径为7.2-7.8μm,大于夏季的藻群体中的细胞直径(4.8-6μm).底泥蓝藻的复苏过程与环境温度变化密切相关.蓝藻在水体温度达到14℃时开始少量进入水柱中,在环境温度升至18-20℃之间时大量进入水中,为水华形成提供了种源.底泥蓝藻的最佳复苏温度(18-20℃)高于非蓝藻的复苏温度(14-18℃),高温对蓝藻复苏更为有利 相似文献
6.
流速对浮游藻类生长和种群变化影响的模拟试验 总被引：3，自引：2，他引：1
采集夏季崇明岛中心湖原水,在环形有机玻璃水槽开展了不同流速对浮游藻类生长和种群变化影响的研究.相对于静止水槽,实验前期不同的流速条件均对浮游藻类的生长产生了一定的抑制作用,实验后期浮游藻类叶绿素a含量均稳定在一定水平,且流动水槽中叶绿素a含量略大于静止水槽,这可能与静止围隔中出现大量枝角类浮游动物有关,而流动条件则抑制了浮游动物的生长,减轻了对浮游藻类的捕食压力.水体流动导致了浮游藻类种群的变化,蓝藻的迅速消失、绿藻和硅藻形成生长优势是主要特征,表明持续的流动条件是导致浮游植物种属减少和群落结构变化的直接原因.该研究可为调水引流在河道、湖泊和水库中的富营养化控制和水华防治提供基础依据. 相似文献
7.
太湖冬季底泥中活体藻类的检测 总被引：11，自引：2，他引：11
2002年冬从太湖梅梁湾采集柱状底泥，取三段进行直接镜检和用MA培养基进行光照培养．镜检发现表层(0-3cm)底泥中有多种藻类细胞，中层(10-13cm)底泥的藻类细胞种类明显减少，下层(20-23cm)底泥中没有发现藻类细胞．底泥培养的结果与之有相似的趋势，但得到的活体藻类细胞的种类相应减少．培养3个月后得到在外观和群落结构上与夏季水华相似的群落．结果表明底泥中的微囊藻和小环藻在太湖底泥中具有良好的适应性，占有明显的优势地位，底泥可以作为水华蓝藻的越冬场所和来年水华的种源． 相似文献
8.
2018年10月-2019年10月对巢湖西湖心水体浮游藻类群落结构以及水体和底泥蓝藻生物量进行了月度调查.结果表明:巢湖西湖心浮游藻类的主要优势种属为微囊藻属、席藻属、十字藻、卵形隐藻和鱼腥藻属.蓝藻优势种属在5-10月为微囊藻属,11-12月为鱼腥藻属,1-4月为席藻属.巢湖水体和底泥蓝藻生物量峰值分别出现在9月和2月,水体蓝藻的衰亡下沉会导致底泥蓝藻生物量的上升.巢湖蓝藻主要分布在水体,底泥蓝藻生物量相对较低,单位面积水柱与底泥蓝藻生物量6月的比值大于100,在11-3月相对较低,最低值小于2.底泥蓝藻主要分布在底泥表层0～2 cm.通过安装原位捕获器,监测了蓝藻在西巢湖湖心水柱和底泥中的垂直迁移过程和通量.结果表明:11月和2月蓝藻有明显从水柱向底泥迁移的过程;底泥蓝藻全年向水体的静态迁移量都很低,而动态迁移在11月和6月出现两个峰值,主要受底泥蓝藻生物量和再悬浮的影响.本研究结果表明削减巢湖西湖心底泥种源的最佳时期为10月至来年2月,但是由于底泥蓝藻生物量远远小于水柱蓝藻生物量,底泥蓝藻向水体复苏迁移的通量也较低,即使削减了底泥种源,也不能有效降低水体蓝藻生物量. 相似文献
9.
太湖水华蓝藻底泥中复苏和水柱中生长的比较 总被引：4，自引：1，他引：4
为了研究太湖底泥中蓝藻的复苏和水柱中的生长,作者自行设计了原位藻类复苏收集器和生长培养器并安放在太湖梅梁湾监测蓝藻复苏释放和生长.实验在藻类的复苏期(2005年3-6月)进行．结果表明在复苏期太湖蓝藻的复苏呈现波动性增加,4月达到最大量．水柱中蓝藻同步的比生长率和生长量也呈现波动性上升,并在5月初达到最大值．浮游动物的存在并没有对蓝藻的生长造成显著的影响．对底泥蓝藻释放和水柱生长进行比较,底泥释放的蓝藻只占藻类生长量的很小一部分(<2．5％)．所以,水柱中蓝藻的生长对其优势的确立和水华的形成具有重要的作用,今后的研究将主要集中在水柱中蓝藻的动态变化 相似文献
10.
对两种水体悬浮颗粒物吸收系数测定方法及相关计算进行对比研究.通过长江中下游湖泊典型藻类的实验室培养,利用T方法和T-R方法分别对藻类颗粒物、藻类泥沙混合悬浊液进行吸收系数测定.通过颗粒物光谱吸收系数与叶绿素a之间的相关性关系,对比了两种方法的测量稳定性.通过对不同比例的藻类和无机悬浮颗粒物(ISS)的混合悬浊液进行分析,获得了不同浊度水体悬浮物吸收光谱的变化情况.结果表明,在纯藻或者泥沙含量较少的水体进行颗粒物吸收系数光谱测定时,T方法和T-R方法均可以采用,并且均具有较高的测定精度.然而,在泥沙含量相对较高的浑浊水体,应尽量选取T-R方法进行颗粒物吸收光谱的测定,以提高测定精度.长江中下游浅水湖泊由于底泥易受风浪影响发生再悬浮,因此在颗粒物吸收系数光谱测定中,当水体中ISS含量超过30 mg/L时,应选择T-R方法. 相似文献
11.
Forms of phosphorus in sediments from 25 lakes in the middle and lower reaches of Yangtze River were analyzed by the sequential extraction procedure. Contents and spatial distrubution of algal available phosphorus (AAP) in sediments of Lake Taihu, the third largest freshwater lake of China, were also studied. Relationships between phosphorus forms in sediment and macrophytes coverage in sample sites, as well as phosphorus forms in sediments and chlorophyal contents in lake water were discussed. Exchangeable form of phosphorus (Ex-P) in surface sediments was significantly positive correlative to total phosphorus (TP), dissolved total phosphorus (DTP) and soluble reactive phosphorus (SRP) contents in the lake water. Bioavailable phosphorus (Bio-P) contents in sediments from macrophytes dominant sites were significantly lower than that in no macrophyte sites. In Lake Taihu, Ex-P content in top 3 cm sediment was highest. However, content of ferric fraction phosphorus (Fe-P) was highest in 4–10 cm. Bioavalilble phosphorus (Bio-P) contents in surface sediments positively correlated to Chlorophyll a contents in water of Lake Taihu with significant difference. Therefore, contents of Bio-P and AAP could be acted as the indicators of risks of internal release of phosphorus in the shallow lakes. It was estimated that there were 268.6 ton AAP in top 1 cm sediments in Lake Taihu. Sediment suspension caused by strong wind-induced wave disturbance could carry plenty of AAP into water in large shallow lakes like Lake Taihu. 相似文献
12.
Phosphorus forms and bioavailability of lake sediments in the middle and lower reaches of Yangtze River 总被引：5，自引：2，他引：5
Forms of phosphorus in sediments from 25 lakes in the middle and lower reaches of Yangtze River were analyzed by the sequential extraction procedure. Contents and spatial distrubution of algal available phosphorus (AAP) in sediments of Lake Taihu, the third largest freshwater lake of China, were also studied. Relationships between phosphorus forms in sediment and macrophytes coverage in sample sites, as well as phosphorus forms in sediments and chlorophyal contents in lake water were discussed. Exchangeable form of phosphorus (Ex-P) in surface sediments was significantly positive correlative to total phosphorus (IP), dissolved total phosphorus (DTP) and soluble reactive phosphorus (SRP) contents in the lake water. Bioavailable phosphorus (Bio-P) contents in sediments from macrophytes dominant sites were significantly lower than that in no macrophyte sites. In Lake Taihu, Ex-P content in top 3 cm sediment was highest. However, content of ferric fraction phosphorus (Fe-P) was highest in 4 - 10 cm. Bioavalilble phosphorus (Bio-P) contents in surface sediments positively correlated to Chlorophyll a contents in water of Lake Taihu with significant difference. Therefore, contents of Bio-P and AAP could be acted as the indicators of risks of internal release of phosphorus in the shallow lakes. It was estimated that there were 268.6 ton AAP in top 1 cm sediments in Lake Taihu. Sediment suspension caused by strong wind-induced wave disturbance could carry plenty of AAP into water in large shallow lakes like Lake Taihu. 相似文献
13.
长江中下游湖泊沉积物生物可利用磷分布特征 总被引：24，自引：5，他引：24
利用化学提取方法对太湖6个样点,巢湖4个样点和龙感湖3个样点的表层沉积物和沉积物柱样进行了生物可利用磷(BAP)测定．北太湖表层沉积物的平均含量为259．5mg／kg,而西部湖区平均含量为114 6mg／kg,湖心区平均含量为40．6 mg/kg,而东太湖平均含量为50．7 mg／kg,呈显著北高南低的特点．巢湖西部湖区表层沉积物的BAP平均含量为 254．2 mg／kg,而东部湖区BAP含量降低为101．9mg／kg．龙感湖表层沉积物BAP平均含量为67．8 mg／kg．显著表明污染程度较高的湖区沉积物的BAP相应较高．BAP在沉积物中随深度呈指数降低,显示生物可利用磷在沉积作用下向稳定的非活性磷转化．夏季沉积物中的BAP由于生物活性的增强向溶解态活性磷转化过程增强,显示为较低的BAP含量．BAP 含量与水体溶解态活性磷呈正相关关系,且该相关性在BAP含量较低的样点好于高BAP的样点． 相似文献
14.
太湖近代沉积物中重金属元素的累积 总被引：23，自引：3，他引：20
利用210Pb、137Cs定年技术,对来自太湖不同生态和沉积特征的三个湖区的沉积物柱状样品进行了定年,用ICP—AES分析了沉积物中重金属等元素的含量,分析了太湖沉积物中重金属的累积特征及其成因.污染较重、蓝藻水华暴发频繁的梅梁湾沉积物中的重金属含量在近25年来逐年增加;太湖上游风浪较大的夹浦湖区表层10cm沉积速率大、粒度粗,除表层1cm外,1—10cm沉积物中各种重金属含量都较低,且层间变化剧烈;下游湖区正逐渐草型化的胥口湾除表层3cm外,沉积物中重金属的含量自底层向表层大致呈不断下降的趋势.研究表明,不同年代的太湖沉积物中重金属含量差异很大,明显大于不同湖区间沉积物重金属平均含量间的差异.水动力作用引起的沉积物粒度分异很可能是影响沉积物中重金属积累的一个重要因素.总体上太湖沉积物中重金属的污染比较轻微,但已经有一定程度的Cd污染,梅梁湾沉积物中自上世纪70年代开始明显积累Cd,其他重金属元素的积累也逐渐增加,值得关注. 相似文献
15.
Study on the simulation of transparency of Lake Taihu under different hydrodynamic conditions 总被引：2，自引：0，他引：2
It was indicated in this study that there were negative relations between the concentrations of suspended solid (SS) and transparency according to the analysis of measured data of Lake Taihu. Their relations in pervious studies were reviewed, which showed that the changes of transparency in Lake Taihu could be reflected by simulating suspended solid concentration (SSC). Measured data showed that the changes of SSC with wind speed were similar at different water depths. SSC increased with the increasing of wind speed. Both wave and lake current of Lake Taihu had positive relations with SSC. However, wave was the main factor affecting sediment suspension, while flow took the second place. In this study, a numerical model coupling lake current, wave and SSC of Lake Taihu was developed. In the SS model, the combined effects of wave and current were included. The amounts of suspended and deposited sediments near the lake bed surface layer were treated separately. The stochastic characteristics of turbulent flow pulsation near lake beds were also considered, and the start-up conditions of sediment suspension were introduced to the model. The model elucidated the mutual exchange processes between sediment particles in SS and active sediments within and on the bed surface layer. Simulated results showed that lake current had relatively significant effects on the SSC at littoral areas of Lake Taihu, while SSC at the central area of the lake was mainly influenced by wave. The changes of transparency with SSC were simulated for Lake Taihu using this model. Calculated results were validated by measured data with good fitness, which indicated that the model is basically suitable for the simulation and prediction of transparency of Lake Taihu. 相似文献
16.
It was indicated in this study that there were negative relations between the concentrations of suspended solid (SS) and transparency according to the analysis of measured data of Lake Taihu. Their relations in pervious studies were reviewed, which showed that the changes of transparency in Lake Taihu could be reflected by simulating suspended solid concentration (SSC). Measured data showed that the changes of SSC with wind speed were similar at different water depths. SSC increased with the increasing of wind speed. Both wave and lake current of Lake Taihu had positive relations with SSC. However, wave was the main factor affecting sediment suspension, while flow took the second place. In this study, a numerical model coupling lake current, wave and SSC of Lake Taihu was developed. In the SS model, the combined effects of wave and current were included. The amounts of suspended and deposited sediments near the lake bed surface layer were treated separately. The stochastic characteristics of turbulent flow pulsation near lake beds were also considered, and the start-up conditions of sediment suspension were introduced to the model. The model elucidated the mutual exchange processes between sediment particles in SS and active sediments within and on the bed surface layer. Simulated results showed that lake current had relatively significant effects on the SSC at littoral areas of Lake Taihu, while SSC at the central area of the lake was mainly influenced by wave. The changes of transparency with SSC were simulated for Lake Taihu using this model. Calculated results were validated by measured data with good fitness, which indicated that the model is basically suitable for the simulation and prediction of transparency of Lake Taihu. 相似文献
17.
微生物参与下的氮循环是富营养化湖泊十分重要的生物地球化学循环过程.采用基于amoA功能基因和16S rRNA基因的荧光定量PCR、PCR-DGGE与高通量测序等分子生物学技术,调查秋季太湖不同水体和表层沉积物中氨氧化古菌(AOA)、氨氧化细菌(AOB)和亚硝酸盐氧化菌(NOB)群落丰度和组成,探讨影响硝化微生物分布的关键环境因子.结果表明,中度富营养化的梅梁湾湖区水体表层、中层和底层水样和表层底泥中AOA amoA基因的丰度分别低于轻度富营养化的湖心区,而不同层水样中AOB amoA基因的丰度分别高于湖心区.梅梁湾湖区和湖心区水样中AOA群落组成基本相似,2个湖区表层沉积物样品中AOA群落组成亦基本相似,水体中AOA群落组成与表层沉积物中AOA群落组成有差异,AOA群落丰度显著受硝态氮、pH和DO影响;表层沉积物中AOB群落丰度有明显差异且显著受总氮含量影响,表层沉积物中NOB群落丰度也有明显差异且显著受亚硝态氮含量影响.太湖梅梁湾湖区和湖心区水体与表层沉积物AOA群落包括Nitrosopumilium和Nitrosotalea两大属;表层沉积物AOB群落主要包括亚硝化单胞菌(Nitrosomonas)和亚硝化螺菌(Nitrosospira)两大属,NOB群落主要包括硝化刺菌(Nitrospina)和硝化螺菌(Nitrospira)两大属,其中硝化螺菌属是淡水湖泊中比较少见的亚硝酸盐氧化菌.影响太湖水体和沉积物中AOA和AOB丰度的最主要环境因子为总氮、总磷与铵态氮.研究表明典型富营养指标(总氮、总磷、铵态氮、硝态氮和硝态氮等)是影响太湖梅梁湾和湖心区水体和沉积物中AOA或AOB丰度以及硝化微生物群落丰度的重要因素. 相似文献
18.
贵州红枫湖越冬藻类的空间分布与实验室复苏实验 总被引：1，自引：0，他引：1
本文选取贵州省红枫湖这一典型的亚深水型湖泊作为研究对象,在8个代表性湖区开展了为期一年的表层水体藻类浮游植物分布的月定量监测,并在4个采样点采集新鲜沉积物进行了越冬藻类赋存与复苏模拟实验研究.研究表明,红枫湖表层水体藻类种群密度蓝藻绿藻>硅藻>甲藻,蓝藻为优势门类,水体藻类种群密度秋季初期最高,其次是春季初期和夏季,具有明显的季节性演化特征.水体中越冬藻类以蓝藻为主,其次是硅藻和绿藻,水深对水体中藻类的种群密度及组成没有显著影响.沉积物中越冬藻类以硅藻为主,基本不含蓝藻.模拟实验表明,水体中的光照条件对藻类的复苏和生长有重要影响,温度和沉积物中藻类的种群密度与组成同样影响藻类的复苏. 相似文献
19.
Contributions of phosphatase and microbial activity to internal phosphorus loading and their relation to lake eutrophication 总被引：3，自引：2，他引：3
Phosphatase may accelerate the process of lake eutrophication through improving phosphorus bioavailability. This mechanism was studied in three Chinese eutrophic shallow lakes (Lake Taihu, Lake Longyang and Lake Lianhua). Phosphatase activity was related to the concentration of soluble reactive phosphorus (SRP) and chlorophyll a. Stability of dissolved phosphatase in reverse micelles may be attributed to molecular size, conformation and active residues of the enzyme. At the site with Microcystis bloomed in Lake Taihu, dissolved phosphatase activity was higher and more stable in micelles, SRP concentrations were lower in interstitial water, the contents of different forms of phosphorus and the amounts of aerobic bacteria were lower while respiration efficiency was higher in sediments. Phosphobacteria, both inorganic and organic and other microorganisms were abundant in surface water but rare in sediments. Therefore, internal phosphorus may substantially flux into water column by enzymatic hydrolysis and anaerobic release, together with mobility of bacteria, thereby initiating the bloom. In short, biological mechanism may act in concert with physical and chemical factors to drive the internal phosphorus release and accelerate lake eutrophication. 相似文献