稻鱼共作生态系统浮游植物群落结构和生物多样性

稻鱼共作技术是中国传统农业的精华,通过对稻鱼共作系统水体浮游植物的种类组成、密度、生物量及多样性进行分析,明确该系统中浮游植物数量变化特性,为进一步开发利用这一经典农艺提供理论基础和实践依据。结果表明,稻田生态系统中浮游植物群落包含蓝藻门、甲藻门、隐藻门、裸藻门、绿藻门和硅藻门等6门,共38属93种。稻鱼共作显著增加稻田水体浮游植物的密度和生物量,降低硅藻和蓝藻的优势度,增加绿藻和裸藻的优势度,提高了稻田水体浮游植物多样性指数。     

珠海地区小型抽水型与非抽水型水库的浮游植物群落结构变化

2006年4月、8月、12月对珠海3座抽水型水库和3座非抽水型水库的水质和浮游植物进行采样和测定.抽水型水库和非抽水型水库的浮游植物分别有67种和56种.蓝藻门的假鱼腥藻(Pseudanabaena sp.)、湖丝藻(Limnothrix redekei)和拟柱孢藻(Cylindrospermopsis rackiborskii)仅在抽水型水库中检到,而绿藻门的鼓藻(Cosmarium sp.)仅在非抽水型水库中检到.抽水型水库浮游植物种类的季节变化比非抽水型水库明显,且浮游植物的丰度和生物量均高于非抽水型水库.抽水型水库浮游植物丰度在1.25×105～4.38×106cells L-1之间,以蓝藻和小型绿藻为主;非抽水型水库浮游植物丰度在7.1×104～4.61×106cells L-1之间,以绿藻门的鼓藻为主.抽水型水库浮游植物的生物量在2.3～8.8 mgL-1之间,非抽水型水库浮游植物的生物量在1.3～5.6 mgL-1之间.抽水型水库浮游植物的生物量在冬春季高于夏季,而非抽水型水库浮游植物的生物量动态相反.抽水型水库浮游植物的优势种具有明显的季节变化.非抽水型水库浮游植物具有相对稳定的群落季节变化,其优势种的组成较为稳定.对于抽水型水库而言,咸潮前期集中调水入库,不仅改变了水库的营养盐负荷,也改变了水库水动力学的季节动态,这也是导致抽水型与非抽水型水库在浮游植物群落结构与动态上存在明显差别的关键因素.     

密云水库的浮游植物群落结构与密度

 1998年的调查研究显示,密云水库库区水体的浮游植物群落为硅藻(Bacillariophyta)—绿藻(Chlorophyta)型,细胞密度为358.76×104·L-1。湖泊的营养特征为浮游植物响应型。1988～1998年库区水体总氮增长48.7％,总磷增长31.2％,浮游植物细胞密度增长41.7％,库区水体已为中营养,并出现了富营养型浮游植物指示种类,例如斜生栅藻(Scenedesmus obliquus(Turp)．Kütz．),铜绿微囊藻(Microcystis aeruginosa Kütz．),湖泊色球藻(Chroococcus limneticus Lemm．)。水体向富营养化发展趋势明显。应加强水环境保护,增加密云水库流域植被覆盖度,净化、涵养水源,以保证密云水库向北京市供水的质量和数量。     

上海崇明岛明珠湖浮游植物群落结构

2007年1月至12月对崇明岛明珠湖的浮游植物群落结构和物种多样性的周年动态进行了初步研究.共发现浮游植物120种, 隶属于8门63属.优势种包括小席藻、微小平裂藻、旋折平裂藻、不定微囊藻和肘状针杆藻.浮游植物的年平均丰度和年平均生物量分别为5361.57×10⁴ cell·L^-1和7.68 mg·L^-1.浮游植物现存量各月间差异极显著(P<0.01),在7月达到最高峰值, 但各站点间差异不显著.浮游植物的Shannon多样性指数和Margalef指数夏秋季低, 冬春季高.生物学评价显示,明珠湖冬春两季的水质要优于夏秋两季, 且目前正处于中富营养阶段, 水体为α-中污型.典范相关分析结果表明, 影响明珠湖浮游植物群落结构的主要因子依次为温度、总磷和总氮.     

安徽城东湖浮游植物群落结构与水质评价

为了解城东湖浮游植物群落结构特征及水质健康状况, 于2016年7、8、9、10、11、12月及2017年10、11、12月对城东湖浮游植物及水质理化指标进行调查分析。鉴定浮游植物8门, 56属, 106种(含变种)。其中以绿藻门种类最多, 为25属50种, 占总种类数的47.17%; 硅藻门次之, 13属23种, 占21.70%, 绿藻和硅藻类物种在城东湖浮游植物群落结构中处于优势地位; 浮游植物主要优势种为颗粒直链藻极狭变种Melosira granulate var. angustissima, 卵形隐藻Cryptomonas ovata, 啮蚀隐藻Cryptomonas erosa, 分歧锥囊藻Dinobryon divergens。2016年及2017年浮游植物细胞丰度月平均值为6.743、5.840×104 cells·L-1, 相对应的生物量为0.884与0.526 mg·L-1; Margalef指数、Shannon-Wiener指数及Pielou指数分别为0.627-3.830, 0.741-4.118, 0.247-0.975, 平均值分别是2.029, 2.193, 0.714。RDA分析显示, 影响城东湖浮游植物群落结构的主要环境因子为透明度、总碱度、溶氧等。水质评价显示, 城东湖水质处于α中污染, 营养水平为中营养状态。     

黑河秦岭河段浮游植物群落结构研究

为研究黑河秦岭河段的浮游植物群落结构特征,于2009年8月至2010年3月对黑河秦岭河段4个采样断面的浮游植物进行了调查和分析。鉴定结果显示该河段浮游植物共4门119种(属),其中硅藻门最多,占藻类总数比例69.4%;绿藻门次之,占藻类总数比例28.2%。种类数季节变化明显,随春夏秋冬依次递减;一年中浮游植物密度浮动于0.36×10~4~21.21×10~4 cell/L之间,季节上为春冬夏秋逐渐降低;生物量变化在0.050 2~1.624 2 mg/L之间,季节上为春夏秋冬逐渐降低;浮游植物物种多样性指数介于2.27~4.73之间,表明该河段浮游植物群落结构稳定,抗外界干扰能力强;Palmer藻类污染指数介于1~14之间,均属轻污染,说明水质良好,但低海拔样点处的污染指数季节性变化大,这表明调查河段水生态环境季节性波动较大。     

汉江中下游浮游植物群落结构及水质评价

南水北调中线工程调水后,汉江中下游水华频发引起社会关注。为掌握调水后汉江中下游浮游植物的群落结构特征,于2017年11月、2018年2月、4月和8月在汉江中下游的8个断面对浮游植物进行了定量调查。调查结果显示：共鉴定浮游植物163种,群落组成以硅藻门（Bacillariophyta）、绿藻门（Chlorophyta）为主,其次是蓝藻门（Cyanophyta）。浮游植物优势种主要为硅藻门的梅尼小环藻（Cyclotellameneghiniana）、颗粒直链藻最窄变种（Melosiragranulatavar.）、变异直链藻（Melosiravarians）、颗粒直链藻（Melosiragranulata）,隐藻门的卵形隐藻（Cryptomonasovata）,蓝藻门的弯曲颤藻（Oscillatoriasp.）和伪鱼腥藻（Pseudoanabaenasp.）,且都有较高的优势度。浮游植物密度和生物量的季节变化范围分别为0.33×10⁶cells/L~1.82×10⁶cells/L和0.49mg/L~7.38mg/L。基于Shannon⁃Weaver多样性指数和Pielou均匀度指数以及优势种评价法对汉江中下游的水质进行评价,判断汉江中下游水质整体处于中污状态。     

惠州西湖浮游植物群落对生态系统修复的响应

2004年对广东惠州西湖实施了生态系统修复示范工程,示范区目前沉水植物丰富,水体常年清澈见底。通过2008年6月至2009年5月对示范区和未进行生态修复的平湖逐月进行浮游植物调查,研究了浮游植物群落对湖泊生态系统修复的响应。结果表明,与未修复的平湖相比,示范区浮游植物数量及群落结构均发生了很大变化。示范区全年浮游植物平均生物量和细胞丰度分别为0.31 mg/L和2.75×106cells/L,均远低于未修复的平湖的3.27 mg/L和197.46×106cells/L;平湖中蓝藻在全年大部分时间占有绝对优势,一些热带富营养化水体中的代表种类(假鱼腥藻)成为优势种类;而示范区蓝藻不占优势,取而代之的是一些隐藻、硅藻和甲藻门的种类。另外,示范区浮游植物丰富度增加,年平均Margalef物种丰富度指数为3.70,显著高于平湖的2.68。因此,重建以沉水生植物为优势的生态系统是抑制浮游植物发展和改善湖泊水环境的有效途径。     

熊河水库浮游植物群落结构的周年变化

自2007年5月至2008年4月对湖北省枣阳市熊河水库的浮游植物群落进行调查和分析.调查共发现浮游植物49属74种,绿藻在种类组成上占绝对优势,共40种,其次为蓝藻,有15种,硅藻11种,甲藻3种,金藻和裸藻各2种,隐藻仅1种.蓝藻存在夏季(7月)高峰,优势种为卷曲鱼腥藻(Anabaena circinalis);硅藻、隐藻和甲藻均存在一个春季(3或4月)高峰,优势种分别为双头针杆藻(Synedra amphicephala)、羽纹脆杆藻(Fragilaria pinnata)、卵形隐藻(Cryptomonas ovata)和二角多甲藻(Peridinium bipes).Simpson多样性指数、Shannon-Wiener多样性指数、Pielou均匀度指数和Margalef丰富度指数的年平均值分别是0.60、2.20、0.76和1.15.多样性指数和均匀度指数具有明显的季节变化规律,但无明显的空间分布规律.     

长江口北支浮游植物群落结构周年变化特征

2010年10月至2011年9月对长江口北支水域的浮游植物进行周年调查,共采集到183种（包括变种和变型）,隶属于7门60属,其中硅藻门种类最多,有35属137种,占浮游植物总种类数的75%。周年优势种为具槽直链藻、中肋骨条藻、条纹小环藻、两栖颤藻、小伪菱形藻双楔变种、颗粒直链藻和小环藻未定种。本次调查中,季节间浮游植物的丰度差异不显著（P〉0.05）,但各月间浮游植物丰度差异显著（P〈0.05）,全年丰度在2.83×10^3～6.18×10^4cells/L之间,其中6月的丰度最高,1月的丰度最低,全年的平均丰度为1.73×10^4cells/L。Pearson相关性分析显示,浮游植物丰度与硝酸盐浓度显著正相关（P〈0.05）,与氨氮浓度极显著正相关（P〈0.01）,含氮营养盐对浮游植物的影响明显。     

Size and species-specific primary productivity and community structure of phytoplankton in Tokyo Bay

Combined methods of size fractionation and single-cell isolationwere used to investigate the seasonal variation of phytoplanktondynamics in Tokyo Bay with an emphasis on primary productivity.Red tides occurred in Tokyo Bay from spring to autumn; a diatom,Skeletonema costatum, and a raphidophycean, Heterosigma akashiwo,were the most important primary producers. Small diatoms andflagellates, including these species, were dominant and showedrapid changes of phytoplankton community structure within severaldays in summer. The nanoplankton (3–20 µm) fractioncontributed most to chlorophyll a concentration and primaryproductivity during spring to autumn, whereas the microplankton(>20 µm) contribution was remarkable in winter. Picoplankton(<3 µm phytoplankton) remained relatively constantthroughout the year. A significant reverse relationship wasobtained between assimilation rate and chlorophyll a contentfor the total and nanoplankton population; the assimilationrate was high at the initial phase of the bloom, then decreasedto a minimum level at the peak of the bloom. Factors controllingthe reduction of assimilation rates at the peak, and changesin phytoplankton community structure, are discussed.     

大亚湾浮游植物群落特征

于2002年冬、春、夏和秋季对大亚湾浮游植物进行采样调查,分析了浮游植物的种类组成、丰度、优势种、多样性及群落结构的季节变化特征和平面分布特征。并讨论了浮游植物与营养盐、水温及环流等环境因子之间的关系。2002年大亚湾浮游植物共鉴定出48属114种(包括变型和变种),丰度范围在5.79×104~5.37×106cells/m3之间,平均值为1.14×106cells/m3。其中硅藻共37属84种,其种数和细胞丰度都占绝对优势,平均丰度为1.08×106cells/m3,其次为甲藻,9属23种,平均丰度为9.91×104cells/m3。此外还鉴定出蓝藻和金藻。大亚湾浮游植物丰度变化呈单一周期型,春夏季高,秋冬季节低。虽然硅藻的丰度占优势,但秋季硅藻丰度降低(占总丰度75.8%)使甲藻和蓝藻所占比例上升。研究得出春夏季大亚湾浮游植物主要以沿岸暖水性种类为主,秋季和冬季除沿岸暖水种之外,广布种和大洋种也较多,尤其在冬季后者占优势。大亚湾浮游植物优势种类多,不同季节既有交叉又有演替。与以往调查资料相比,部分优势种发生变化,优势程度顺序和细胞丰度发生了一定改变,个体较大的细胞丰度优势逐渐增加。另外,受季风、潮流、地理位置及人类活动影响,大亚湾浮游植物丰度和群落结构有一定的季节和平面分布特征。大亚湾浮游植物的多样性在夏季偏低,尤其在大亚湾核电站和大鹏澳养殖区附近表现明显。大亚湾浮游植物的丰度、种数、优势种演替及群落结构等其它群落特征与营养盐尤其是氮、磷和N/P、水温、环流等环境因子密切相关。     

Herbivoran impact on phytoplankton community structure

An enclosure experiment was conducted to assess the effects of a zooplankton elimination on the structure of a phytoplankton community. Phytoplankton biomass and production were higher in grazer-free enclosures, while the productivity per unit biovolume was lower. Exclusion of zooplankton favoured the majority of algal species, especially chrysophyceans (Dinobryon spp.) and the diatom Rhizosolenia, while mucilagineous green-algae were disfavoured. Middle sized algae (ESD 15–50 µm) and those with the largest Surface Area/Volume ratio were proportionally most favoured by the elimination of grazers.These differences in phytoplankton community structure are discussed in relation to effects of direct selective grazing and nutrient recycling by zooplankton. Some differences, as the immediate positive response of Dinobryon and Rhizosolenia, are probably caused by grazing release, while others, e.g. the response of mucilagineous species, might be caused by changed competitive relationships between the algae.     

Bacterial community structure of a pesticide-contaminated site and assessment of changes induced in community structure during bioremediation

The introduction of culture-independent molecular screening techniques, especially based on 16S rRNA gene sequences, has allowed microbiologists to examine a facet of microbial diversity not necessarily reflected by the results of culturing studies. The bacterial community structure was studied for a pesticide-contaminated site that was subsequently remediated using an efficient degradative strain Arthrobacter protophormiae RKJ100. The efficiency of the bioremediation process was assessed by monitoring the depletion of the pollutant, and the effect of addition of an exogenous strain on the existing soil community structure was determined using molecular techniques. The 16S rRNA gene pool amplified from the soil metagenome was cloned and restriction fragment length polymorphism studies revealed 46 different phylotypes on the basis of similar banding patterns. Sequencing of representative clones of each phylotype showed that the community structure of the pesticide-contaminated soil was mainly constituted by Proteobacteria and Actinomycetes. Terminal restriction fragment length polymorphism analysis showed only nonsignificant changes in community structure during the process of bioremediation. Immobilized cells of strain RKJ100 enhanced pollutant degradation but seemed to have no detectable effects on the existing bacterial community structure.     

胶州湾浮游植物水华期群落结构特征

根据2001年8月对胶州湾海域进行的为期2d的大面积调查资料,对浮游植物的群落结构进行了初步研究,结果表明,浮游植物群落主要由沿岸暖水性种类组成,以硅藻为主,共34种;还有少量的甲藻7种和绿藻1种,湾中央水域出现的物种数最多,为37种;湾边缘最少,仅出现10种,细胞数量的密集区出现在湾东部边缘水域,最高值为6．96×10⁸个cell·m^-3;低值区出现在湾口,最低值仅为3．18×10⁶个cell·m^-3调查期间浮游植物的物种多样性及其均匀度的最低值均出现在湾东部边缘水域;高值区出现在湾口和湾中央水域,胶州湾海域水团运动和水体富营养化程度是影响浮游植物群落分布的主要环境因素。     

Distribution of phytoplankton community in Kotor Bay (south-eastern Adriatic Sea)

The goal of this paper was to explain variability of phytoplankton in a shallow coastal area in relation to physico-chemical parameters. Temporal variability and composition of phytoplankton were investigated in the Kotor Bay, a small bay located in the south-eastern part of the Adriatic Sea. Samplings were performed weekly from February 2008 to January 2009 at one station in the inner part of the Kotor Bay, at five depths (0 m, 2 m, 5 m, 10 m, 15 m). Phosphates, nitrites and nitrates ranged from values under the level of detection to the maximum values of 1.54, 1.53 and 23.91 μmol l⁻¹, respectively. The phytoplankton biomass — represented by chlorophyll a concentration — ranged from 0.12 to 6.78 mg m⁻³, reaching a maximum in summer. Diatoms were present throughout the whole sampling period, reaching the highest abundance in March (3.42×10⁵ cells l⁻¹at surface). The peak of dinoflagellates in July (2.2×10⁶ cells l⁻¹ at surface) was due to a single species, Prorocentrum micans. The toxic dinoflagellate Dinophysis fortii occurred at a concentration of 2140 cells l⁻¹ in May. The present results of phytoplankton assemblages and distribution provide valuable information for this part of the south-eastern Adriatic Sea where data is currently absent.     

基于夜间灯光数据的环杭州湾城市扩张及植被变化

综合运用遥感与GIS技术,基于2000、2007和2013年的DMSP/OLS夜间灯光数据和MODIS NDVI数据,利用灯光阈值提取法、植被指数分析等方法,研究环杭州湾地区城市扩张和建成区植被变化特征.结果表明: 采用最佳阈值方法,能够实现对城市地区用地信息的有效提取;环杭州湾地区城市用地整体围绕杭州湾呈“V”型模式扩展,并表现出面状、线状和点状3种扩张模式;从城市扩张速度、动态度和形态紧凑度来看,各地级市表现出较大的时空差异,但整个研究区的城市扩张速度和动态度普遍呈现降低趋势,平均城市形态紧凑度则经历了先下降后上升的过程.各城市建成区的植被状况也存在显著差异,2000—2007年,除嘉兴市建成区植被状况变差外,其余各地级市建成区植被状况均变好;2007—2013年,所有城市建成区植被状况变差;2000—2013年,城市扩张对建成区植被均产生了不利影响.     

海州湾人工鱼礁海域春、夏季浮游植物群落结构及其与环境因子的关系

根据2009年5月和8月海州湾人工鱼礁建设海域水化学和浮游生物调查资料,对浮游植物群落结构进行了研究,并运用灰色关联分析方法对浮游植物丰度与环境因子的关系进行相关性分析。结果表明,海州湾浮游植物群落组成以硅藻为主;浮游植物丰度的时间分布以夏季平均丰度为3.06×106 cells／m^3,高于春季的3.12×104 cells／m^3;空间分布表现为鱼礁区高于对照区,以夏季鱼礁区站点R5的7.97×106cells／m^3最高,其次为夏季R3的7.53×106cells／m^3;对群落多样性的研究表明,春、夏两季鱼礁区香农一威纳指数（H＇）均值均高于对照区;春季影响浮游植物丰度的主要环境因子依次为：可溶性无机氮（DIP）、BOD5和悬浮物（SS）,而活性硅酸盐（SiO3-Si）、活性磷酸盐（PO4-P）和BOD5对夏季浮游植物丰度影响较大。     

Linking traits to species diversity and community structure in phytoplankton

In addition to answering Hutchinson’s question “Why are there so many species?”, we need to understand why certain species are found only under certain environmental conditions and not others. Trait-based approaches are being increasingly used in ecology to do just that: explain and predict species distributions along environmental gradients. These approaches can be successful in understanding the diversity and community structure of phytoplankton. Among major traits shaping phytoplankton distributions are resource utilization traits, morphological traits (with size being probably the most influential), grazer resistance traits, and temperature responses. We review these trait-based approaches and give examples of how trait data can explain species distributions in both freshwater and marine systems. We also outline new directions in trait-based approaches applied to phytoplankton such as looking simultaneously at trait and phylogenetic structure of phytoplankton communities and using adaptive dynamics models to predict trait evolution.