基于遥感反射率的太湖优势藻识别方法

我国淡水湖库频发水华,不同类群形成的水华特征、危害及其治理方法差异显著,因此,如何区分不同藻种的遥感反射率特征,获取湖泊优势种信息是一个亟待解决的科学问题。研究基于室内藻种培养实验,培养了富营养化湖泊中的典型蓝藻和绿藻藻种,其中,蓝藻包括铜绿微囊藻（Microcystis aeruginosa）、假鱼腥藻（Pseudanabaenasp．）和束丝藻（Aphanizomenonsp．）,绿藻包括小球藻（Chlorellasp．）以及四尾栅藻（Scenedesmus quadricauda）;基于实测的遥感反射率,经归一化处理后,分析了不同藻种的遥感反射率特征,构建了DI(difference index)指数以及ADI(algae distinguish index)指数,建立了藻种分类模型,利用验证集数据进行检验,整体识别精度达77.55%,Kappa系数为0.7178。将分类方法应用于太湖野外实测遥感反射率数据集中,结果与实测的生物量数据有较好的匹配;将模型应用于太湖OLCI(ocean and land colour instrument)影像数据,获得了2019年12月和2020...     

Phytoplankton Distribution in an Oligotrophic Pond and a Eutrophic Pond

Summary: An oligotrophic pond and a eutrophic pond of Bhagalpur, India, were studied for phytoplankton distribution and to establish the relationship between this distribution and the physico-chemical properties of the water. Altogether, 114 algal taxa were identified. In Rekabganj pond, diatoms constituted 54.4 % of the algal species followed by green algae (29.4 %), blue greens (11.7 %) and euglenoids (2.9 %). In Ramna pond, blue greens were the most dominant comprising 35.7 % of algal species followed by green algae (32.8 %), diatoms (18.5 %) and euglenoids (8.5 %). The members of Dinophyceae, Chrysophyceae and Xanthophyceae were poorly represented in both the water-bodies. Aphanizomenon flos-aquae, Microcystis aeruginosa, Chlorella vulgaris, Cladophora crispata, Volvox aureus and Euglena spp. were recorded only in Ramna pond, indicating its higher nutrient status. Dinobryon calciformis, many pennate diatoms and desmids, indicators of oligotrophy, were observed in Rekabganj pond only. Measurements of water properties in the two ponds showed that transparency, dissolved oxygen and silicate were higher in Rekabganj pond than in Ramna pond, while total alkalinity, hardness, total dissolved solids, dissolved organic matter, different cations, phosphate, nitrate and chloride were lower in Rekabganj pond than in Ramna pond.     

Studies of the Biochemical Composition of Freshwater Plankton Part 2: The Amino Acids Contents in Green and Blue-Green Algae

The composition of bound amino acids was studied in selected types of green and blue-green plankton algae by means of a new elaborated method, using paper chromatography at the triple development of the chromatogram in the set-up: butanol: acetic acid: water at the rate of 4 : 1 : 5. Algologically and bacterially pure cultures of the green algae Ankistrodesmus falcatus, Haematococcus pluvialis, Chlorella pyrenoidosa, Pediastrum boryanum, Scendesmus obliquus and of the blue-green algae Anacystis nidulans, Microcystis pulverea and Microcystis aeruginosa were cultivated in inorganic and in organic medium. The contents of amino acids in green algae were qualitatively and quantitatively evaluated in relation to their physiologic condition (phase of logarithmic growth, phase of stagnation) and to the method of nutrition. The results were compared with the contents of amino acids in blue-green algae obtained in monocultures from freshwater at blue-green algae water blooms. The composition of bound amino acids was studied in selected types of green and blue-green plankton algae by means of a new elaborated method, using paper chromatography at the triple development of the chromatogram in the set-up: butanol: acetic acid: water at the rate of 4 : 1 : 5. Algologically and bacterially pure cultures of the green algae Ankistrodesmus falcatus, Haematococcus pluvialis, Chlorella pyrenoidosa, Pediastrum boryanum, Scendesmus obliquus and of the blue-green algae Anacystis nidulans, Microcystis pulverea and Microcystis aeruginosa were cultivated in inorganic and in organic medium. The contents of amino acids in green algae were qualitatively and quantitatively evaluated in relation to their physiologic condition (phase of logarithmic growth, phase of stagnation) and to the method of nutrition. The results were compared with the contents of amino acids in blue-green algae obtained in monocultures from freshwater at blue-green algae water blooms. The following amino acids were found in the organismus of primary production: alanine, aspartic acid, arginine, cysteine, glutamic acid, histidine, isoleucine, leucine, lysine, proline, serine and glycine, threonine, tryptophane, tyrosine and valine. The following amino acids were predominant from the quantitative aspect: glutamic acid, threonine and serine and glycine. The composition of amino acids in green algae cultivated in an inorganic medium did not differ significantly from cultures cultivated in an organic medium. Differences in the quantitative composition of the individual amino acids were ascertained with green algae in relation to their physiologic condition.     

若干水华相关藻类对太湖水体异味物质贡献的初步研究

太湖水体中嗅味物质2-甲基异莰醇(MIB)和土臭素(Geo)的出现与水华发生在时间上高度重叠,为探寻水华中常见藻类与嗅味的关系,本研究通过对实验室培养藻株和野外水样比较分析,探寻了部分藻株与太湖水体嗅味物质的关系.分析实验室培养的15株蓝藻(其中11株微囊藻)、4株绿藻和4株硅藻,仅硅藻培养物测定出了Geo,所有藻株均未检测出MIB;对太湖典型水样分析结果显示,水体中MIB与Geo的浓度与微囊藻细胞浓度无相关性;实验室模拟微囊藻水华腐败结果显示,无论是好氧还是厌氧条件下均未产生MIB和Geo;这些数据结果说明湖水中MIB和Geo与水华主要种群微囊藻无直接关系.在鱼腥藻水华中测出了高浓度的MIB,周年水样分析结果显示鱼腥藻细胞数与MIB浓度变化规律一致,因此鱼腥藻可能是MIB的重要来源.但实验室培养的Anabaena sp.PCC7120无论是在缺氮还是有氮培养条件下均不产MIB和Geo,说明嗅味物质的产生具有藻株特异性.     

Möglichkeiten der Nachreinigung von Abwässern aus der Kunstlederproduktion mit Hilfe von Algen

In the production of a special artificial leather (BAREX) in the CSSR wastewaters containing dimethylformamide (DMF) and dimethylamine (DMA) are produced. Investigations have shown that cultures of algae (Scenedesmus quadricauda) are able to use the two substances as a nitrogen nutrient source after a time of adaptation. In the course of the reactions of decomposition the pH-value plays an important part, since at increased values ammonia is released, which has a temporarily inhibitory effect on the production of algae masses and daughter cells. This detrimental effect can be considerably reduced by aeration with carbondioxide containing (3%) air. Since the production of algal biomass is restricted by a phosphorus deficiency, too, a combined treatment with municipal sewage is very advantageous, according to the results from investigations.     

近1800年以来内蒙古达里湖浮游植物群落演变及驱动因素

湖泊是地质历史上区域生态环境演变的重要载体,其沉积物中包含了丰富的环境演变信息。达里湖是典型的草原内陆封闭型湖泊,位于东亚夏季风的北部边缘,地理位置关键。本研究基于在达里湖采集的约238 cm沉积物岩芯 (GDL-1),通过²¹⁰Pb和¹³⁷Cs (岩芯上部20 cm)、AMS¹⁴C测年,以及沉积物样品中甾醇等生物标志物含量分析,重建了近1800年以来达里湖硅藻、蓝藻等典型藻类含量的演化历史,并结合总氮(TN)、总磷(TP)、盐度(Sr/Ba)和温度(T)等环境代用指标,分析藻类群落的主要影响因素。结果显示达里湖典型藻类总量平均为2.03 ng/g(最高6.69 ng/g,最小0.53 ng/g),其中蓝藻占比平均为60%,绿藻和硅藻占比平均为20%;环境因子对硅藻、蓝藻和典型藻类生物量的解释率分别为47.7%、55.20%和48.10%,T、TN和Sr/Ba是影响浮游植物群落的主要影响因素;硅藻占比与温度呈显著负相关,小冰期硅藻占比最高,中世纪暖期占比最低;在达里湖的高盐环境下,湖泊营养盐浓度对藻类的影响受到限制,成为藻类等生长的限制因素;Sr/Ba小于0.9时,硅藻含量与典型藻类总量随着Sr/Ba值的升高而增加,Sr/Ba大于0.9时,典型藻类总量与Sr/Ba值呈负相关关系,而硅藻则表现出对盐度具有一定的耐受性;整体上,近1800年以来,区域或全球性气候事件通过改变达里湖盐度、营养元素浓度和温度来影响典型藻类群落结构。在暖期阶段,蒸发作用增强等导致的湖泊盐度增加成为达里湖典型藻类群落结构演变的主要影响因素;在冷期,营养元素浓度和温度的降低成为湖泊水体浮游植物生物量的主要影响因素。     

Chemical and biological processes in coquina of Castillo de San Marcos National Monument

Analyses of water flowing through coquina showed exclusion of atmospheric CO₂ and supersaturation in respect to calcite and hydroxyapatite. Extensive populations growing on the walls and benefiting from these nutrients included mainly blue-green algae, green algae and diatoms.     

Zur Bestimmung einer rotenOscillatoria— ein Beitrag zur Variabilität vonOscillatoria rubescens D.C.

Summary For the purpose of determination a redOscillatoria species was after isolation cultivated and compared withO. rubescens (clones 51,Staub). Increase of trichoms and dry matter, length and diametre of trichoms and length of cells were measured; total volume of gas vacuoles and spectral absorption of the algal suspension between 380–730 nm were determined. The algae under discussion were attached to the speciesO. rubescens. Differences and accordances between the species studied andO. rubescens andO. prolifica as well, heterogeneity ofO. rubescens and variability of the characteristics ofO. rubescens are discussed.      

贵州红枫湖越冬藻类的空间分布与实验室复苏实验

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.     

A Simple In Vivo Fluorescence Method for the Selective Detection and Quantification of Freshwater Cyanobacteria and Eukaryotic Algae

A method for the rapid detection of cyanobacteria (blue‐green algae) and their differentiation from eukaryotic algae in natural phytoplankton assemblages is presented. Fluorescence emission of photosynthetic pigments at 670 nm was measured using a microplate fluorescence reader when excited at two different wavelengths – 485 nm and 590 nm. The ratio of fluorescence excited at these wavelengths (590 nm/485 nm) was proportional to the ratio of cyanobacteria and eukaryotic algae, which was determined by the in situ spectrofluorometer for the phytoplankton quantification. The fluorescence intensity was equal to the total chlorophyll‐a content. These two fluorescence values can provide the first warning on a development of potentially toxic cyanobacteria in water.     

Untersuchungen über die Struktur des Centroplasmas und die Drehrichtung einigerOscillatoriaarten

Zusammenfassung An vier verschiedenen Arten der GattungOscillatoria konnte nach Anf?rbung mit Acridinorange im Fluoreszenzmikroskop die Feinstruktur des Centroplasmas beobachtet werden. Besonders deutlich liessenO. animalis undO. terebriformis feine L?ngsstrukturen erkennen, die schr?g zur Trichomachse ausgerichtet waren und auf einen spiraligen Bau des gesamten Protoplasten schliessen liessen. Voraussetzung für diese Versuche waren junge Algen aus 3–4 Tage alten Kulturen. Die Anordnung der nukleins?urehaltigen Strukturen in den Zellen stimmte mit der Drehrichtung der lebenden Algen überein. Es wird angenommen, dass die Windungsrichtung der Oscillatorien artspezifisch ist.

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Summary It was possible, after staining with acridin orange, to observe in the fluoromicroscope the fine structure of the centroplasm of four different species of the genusOscillatoria. Especially in the case ofO. animalis andO. terebriformis, fine longitudinal structures could be distinguished; they run obliquely towards the trichome axis and could be a sign of spiral structure of the whole protoplast. Such structures can be observed only on young algae taken from cultures 3 or 4 days old. The arrangement of the nucleinate structures in the cells corresponds to the twisting movement of the live algae. It can be supposed that the twisting direction taken by the Oscillatoria is characteristic of the species.

     

东江惠州河流段人工基质附着硅藻群落的季节性动态

硅藻群落结构特征是反映河流水生态状态的重要生物指标,但我国多数河流中还缺少硅藻种类组成与季节变化的基本数据.2010年用瓷砖片作为人工基质研究东江惠州河流段附着硅藻群落结构的季节性变化,共鉴定出附着硅藻40属153种(包括亚种和变种),主要的优势属有曲壳藻属(Achnanthidium)、异极藻属(Gomphonema)、直链藻属(Melosira)、舟形藻属(Navicula)、菱形藻属(Nitzschia)、脆杆藻属(Synedra)等.Gomphonema parvulum和Nitzschia palea为该河流段的广泛性藻种,且相对丰度的季节性变化明显.RDA分析表明,水温、DO、NH4+-N、PO34--P、电导率、pH值等对附着硅藻群落结构有重要影响.在丰水期,水量对于运动能力较强的N.palea的相对丰度具有明显的影响.     

Studies of the biochemical composition of fresh-water plankton. Part 1: The protein contents in green and blue-green algae

Lowry's method, adapted to the analysis of small amounts of fresh-water plankton, was selected for the basic evaluation of the published methods of determination of proteins in algae. The protein contents were studied by this method in aqueous, alcohol and sodium hydroxide extract from green algae of the types Ankistrodesmus falcatus, Haematococcus pluvialis, Chlorella vulgaris, Scenedesmus obliquus, Pediastrum boryanum, Chlorococcus spec. and from blue-green algae Microcystis pulverea, M. aeruginosa and Anacystis nidulans. These organisms were cultivated in artificial media under standard conditions and the analysis of proteins was carried out during the growth and stagnation phases. The largest amount of proteins was ascertained in extracts of 2N NaOH, amounting to 7 … 44% according to the dry substance (aqueous extract 1 … 48%, alcohol extract 1 … 23%). As the ageing of the cultures of green algae proceeded, the amount of dry substance increased, but the protein contents decreased. In the samples of blue-green algae there were in all cases the protein contents higher in the stationary phase than in the growth phase.     

Effects of lanthanum(III) and EDTA on the growth and competition of Microcystis aeruginosa and Scenedesmus quadricauda

Rare earth elements (REEs) are widely used to increase crop production in China. However, little attention has been paid to their impacts on aquatic ecology. Batch cultivation was used here to study the effects of lanthanum (La) and EDTA on the growth and competition of the cyanobacterium Microcystis aeruginosa and the green alga Scenedesmus quadricauda. When EDTA was present at a very low concentration (0.269 μmol L⁻¹), low lanthanum concentrations (?7.2 μmol L⁻¹) had little stimulative effect on the growth of M. aeruginosa and S. quadricauda, whereas a high lanthanum concentration (72 μmol L⁻¹) had significant inhibitory effect on both of them. The results of cultivation experiments suggested that the inhibitory effect on M. aeruginosa was higher than that on S. quadricauda and S. quadricauda could become dominant in mixed cultures. When lanthanum was not added to the culture medium, high EDTA concentrations (>13.4 μmol L⁻¹) had a great inhibitory effect on the growth of M. aeruginosa but little effect on the growth of S. quadricauda, which could become dominant in the mixed cultures.Lanthanum and EDTA had complex effects on the growth and competition of M. aeruginosa and S. quadricauda. EDTA did not change the stimulation of low lanthanum concentrations on both, but at intermediated concentrations (2.69-13.4 μmol L⁻¹) it could greatly alleviate lanthanum inhibition on M. aeruginosa; thus, M. aeruginosa would dominate S. quadricauda in these mixed cultures. Lanthanum at low concentration (7.2 μmol L⁻¹) could also alleviate the inhibition of high EDTA on M. aeruginosa, but did not alter the outcome of the competition.     

太湖水体吸收分解(Ⅱ):浮游植物色素吸收分解

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.     

Phytoplankton absorption spectra along the water column in deep North Patagonian Andean lakes (Argentina)

During a summer period we studied the vertical variation of in vivo and chlorophyll a specific phytoplankton absorption spectra in relation to the underwater light climate of ten deep North Patagonian Andean lakes of Argentina. The lakes were thermally stratified, and the underwater light climate was characterized by extended euphotic zones which included highly illuminated epilimnetic layers (both UVR and PAR) and metalimnia exposed to dim blue-green light. Most of the lakes presented the development of Deep Chlorophyll Maxima (DCM) at the metalimnetic layers, near 1% of surface PAR irradiance. Analyzing the fourth-derivative plots of in vivo phytoplankton absorption spectra [d^IVa_ph(λ)], we were able to identify several maxima absorption values attributed to different pigments. Considering lakes with DCM, a significant positive linear relationship was found between d^IVa_ph (495–500 nm) normalized by chlorophyll a and downward irradiance. Indeed, a negative significant relationship was found between d^IVa_ph (495–500 nm) normalized by chlorophyll a and diffuse PAR attenuation coefficients. These results point out an increase in the relative concentration of different carotenoids at surface layers indicating the role of photoprotection of these pigments. On the other hand, significant negative linear relationships were found between fourth-derivative spectra normalized by chlorophyll a at 650, 590–595, 560–565 and 520–525 nm and downward irradiance. These results indicated an increase in the relative concentration of photosynthetic accessory pigments at deep layers of the euphotic zone. Furthermore, we found a decrease in depth of specific absorption spectra at 440, 670 nm and in the ratio a_ph* (440 nm) to a_ph* (670 nm). This pattern was associated with the package effect concept. The increase in relative photosynthetic accessory pigment concentrations and the decrease in values of specific absorption spectra at the bottom of the euphotic zone were attributed to changes in phytoplankton communities between surface and deep layers. These outcomes pointed out that the underwater light climate and temperature water structure are, like in marine systems, very important factors governing the distribution of phytoplanktonic organisms. In addition, the possession of specific photosynthetic accessory pigments suggests that dominant species in the DCM are well adapted to these dim blue-green light scenarios.     

Life-stage differences in the diet of Parabroteas sarsi (Daday) (Copepoda, Calanoida): A field study

The diet of P. sarsi in different life-stages from copepodid I to adult was investigated. Gut contents of copepodid I to II consisted mainly of algae such as diatoms and dinoflagellates. From copepodid III to adult stages the composition of the diet changed towards the inclusion of nauplii, cladocerans and copepods. The importance of the algae on the diet decreased with the inclusion of the prey items. Copepods were the most important components of the diet from C V to adult. Differences in the capture and ingestion of cladocerans and copepods were found. Diet of P. sarsi can be characterized as diverse consisting of diatoms, phagotrophic algae, protozoans, rotifers and nauplii from C I to C III and consisting mainly of carnivorous items from C IV to adult. The ability to eat a variety of food allows the copepods to modify their diet with varying conditions in the food environment. The effect of these diversity in the diet seems to be advantageous, specially in stressed environments imposed by episodes of drying.     

Simultaneous inversion of velocity structures and hypocentral locations: Application to the Friuli seismic area NE Italy

A layeredP- andS-wave velocity model is obtained for the Friuli seismic area using the arrival time data ofP- andS-waves from local earthquakes. A damped least-squares method is applied in the inversion.The data used are 994P-wave arrival times for 177 events which have epicenters in the region covered by the Friuli seismic network operated by Osservatorio Geofisico sperimentale (OGS) di Trieste, which are jointly inverted for the earthquake hypocenters andP-wave velocity model. TheS-wave velocity model is estimated on the basis of 978S-wave arrival times and the hypocenters obtained from theP-wave arrival time inversion. We also applied an approach thatP- andS-wave arrival time data are jointly used in the inversion (Roecker, 1982). The results show thatS-wave velocity structures obtained from the two methods are quite consistent, butP-wave velocity structures have obvious differences. This is apparent becauseP-waves are more sensitive to the hypocentral location thanS-waves, and the reading errors ofS-wave arrival times, which are much larger than those ofP-waves, bring large location errors in the joint inversion ofP- andS-wave arrival time. The synthetic data tests indicated that when the reading errors ofS-wave arrivals are larger than four times that ofP-wave arrivals, the method proposed in this paper seems more valid thanP- andS-wave data joint inversion. Most of the relocated events occurred in the depth range between 7 and 11 km, just above the biggest jump in velocity. This jump might be related to the detachment line hypothesized byCarulli et al. (1982). From the invertedP- andS-wave velocities, we obtain an average value 1.82 forV _p /V _s in the first 16 km depth.     

Source mechanism and rupture propagation in the Mudurnu Valley,Turkey, earthquake of July 22, 1967

Summary First motions ofP waves and amplitude spectra ofG ₂ andG ₃ waves have been used to determine the source mechanism and rupture propagation. The amplitudes ofG ₃ waves have been corrected for the attenuation using aQ-model obtained from the amplitude spectra ofG ₂ andG ₃ waves. Observed directivities for the strike-direction agreed with a model of a bilateral fault propagated primarily from east to west.     

Predictors of the peak width for networks with exponential links

We investigate optimal predictors of the peak (S) and distance to peak (T) of the width function of drainage networks under the assumption that the networks are topologically random with independent and exponentially distributed link lengths. Analytical results are derived using the fact that, under these assumptions, the width function is a homogeneous Markov birth-death process. In particular, exact expressions are derived for the asymptotic conditional expectations ofS andT given network magnitudeN and given mainstream lengthH. In addition, a simulation study is performed to examine various predictors ofS andT, includingN, H, and basin morphometric properties; non-asymptotic conditional expectations and variances are estimated. The best single predictor ofS isN, ofT isH, and of the scaled peak (S divided by the area under the width function) isH. Finally, expressions tested on a set of drainage basins from the state of Wyoming perform reasonably well in predictingS andT despite probable violations of the original assumptions.