共查询到20条相似文献,搜索用时 62 毫秒
1.
南太湖浮游植物特征及其富营养化评价 总被引:3,自引:0,他引:3
《生态学杂志》2009,28(11)
2008年8-9月对南太湖的浮游植物进行了调查,并对9个采样点水样进行了分析.结果表明:共有浮游植物47种,隶属于7门28属,其中蓝藻门 6属9种,绿藻门10属13种,硅藻门7属18种,裸藻门2属3种,隐藻门 1属2种,金藻门1种,甲藻门1种;南太湖浮游植物的密度为3.56×10~6~7.99×10~6 cells·L~(-1);浮游植物的Shannon-Weaver多样性指数为0.29~2.27,均匀度指数在多数位点<0.5,卡尔森营养状态指数(TSIM)均大于64;根据浮游植物的优势种组成、密度、多样性指数及富营养状态指数的评价结果说明南太湖处于富营养化阶段.Abstract: In August-September 2008, an investigation was made on the phytoplankton in south-ern Taihu Lake, and the water quality at nine sampling sites was analyzed. A total of 47 phyto-plankton species belonging to 28 genera and 7 phylums were collected, with 9 species of Cyano-phyta, 13 species of Chlorophyta, 18 species of Diatoms, 3 species of Euglenophyta, 2 species of Cryptophyta, 1 specie of Chrysophyta, and 1 specie of Dinophyta. The phytoplankton density was 3.56×10~6-7.99×10~6 cells·L~(-1), Shannon-Weaver index was 0. 29-2. 77, evenness was low-er than 0. 5, and trophic state index (TSIM) was higher than 64. Based on the evaluation of the dominant species composition, density, and Shannon-Weaver index of phytoplankton, and of the TSIM, the southern Taihu Lake was considered at the stage of eutrophication. 相似文献
2.
以浮游植物评价巢湖水质污染及富营养化 总被引:33,自引:2,他引:33
对巢湖浮游植物在22个样点,四季采样,进行了种类组成、种群数量、优势种、污染指示种,多样性指数及硅藻指数等群落生态学的初步研究。选用其中种群数量、优势种、污染指示种、硅藻指数对巢湖水质污染及营养水平进行了总评与分区评价。就巢湖总体而论,藻量年均值达111×10~6个/升(细胞数,或个体数为14.7×10~6个/升),硅藻指数96.7,群落组成种类中,污染指示种占64.2%,除冬季外,各样点多以微囊藻、鱼腥藻为主的蓝藻占优势,其分布频度年平均达98.8%,多度年平均达79.7%,而在夏、秋季,两者则分别为100和99.7%,表明巢湖已受到中等程度的污染,属蓝藻型富营养湖泊;与过去巢湖浮游植物的调查资料对比,表明最近几年来,人为富营养化进程在加速。 相似文献
3.
水体富营养化与浮游植物的指示作用 总被引:1,自引:0,他引:1
水体富营养化是当今人类面临的诸多环境问题之一。当一些流动缓慢的水体,如湖泊、河流、水库以及近海水域,水中氮、磷等营养盐类和有机物含量增高时,在适宜条件(主要是光照和温度)下,水生生物(主要是浮游植物)就会大量繁殖,在水面成层或水中成团分布。由于占优势的浮游植物所含的色素不同而使水体产生不同的颜色,如蓝绿色、黄色、乳白色、红色等,这种现象被人们称为“水华”或“赤潮”。发生水华或赤潮的水体与大气的气体交换受阻,加之水中生物呼吸作用对溶解氧的消耗,使水体溶解氧严重缺乏(特别是日落后至日出前),造成鱼类… 相似文献
4.
肇庆星湖浮游植物状况及其富营养化评价 总被引:13,自引:0,他引:13
研究了 1 996年 4月至 1 997年 7月肇庆星湖 5个子湖泊浮游植物种类和数量变化。在 1 996年 4月至 1 997年 7月 6次采样中 ,共鉴定出浮游植物 82种 ,其中绿藻门 37种 ,其次为硅藻和蓝藻门 ,优势种有鼓藻、栅藻、衣藻、席藻、直链藻、多甲藻和裸藻等。大多数采样点年平均浮游植物密度为 1 0 4 个 /L至 1 0 5个 /L,整个湖泊年平均密度为 4.2 8× 1 0 5个 /L。星湖各子湖泊全年的总氮、总磷含量分别低于 1 mg/L和 0 .1 mg/L ,以叶绿素 a、总氮、总磷、氨氮、COD和 BOD为参数的营养状态指数 (TLI) ,除波海湖外均小于 50。根据浮游植物种类和密度及综合营养状态指数评价结果 ,星湖的富营养化状况属于中营养化至富营养化之间 ,其中波海湖已达到富营养化水平 ,5个湖泊的富营养化程度由高至低依次为 :波海湖、仙女湖、里湖、青莲湖、中心湖。 相似文献
5.
武汉东湖浮游植物的演变(1956-1975年)和富营养化问题 总被引:41,自引:0,他引:41
本文根据1956-1957、1962-1963和1973-1975年在湖北省武汉市东湖进行的三次调查资料,总结了过去二十年内在东湖两个代表性采样站上浮游植物群落生态学的主要变化(包括数量、种类组成、优势种类、多样性指数和初级生产力)。年平均总数在二十年内由每毫升几百个增为几千个。由甲藻和硅藻占优势逐步转变为以绿藻和蓝藻占优势,蓝藻中的大型种类明显增加。年数量变动曲线原来呈春季和秋季两个高峰,但60年代后,已变为夏、秋季的一个蓝藻高峰,而且数量大,延续时间长。浮游植物的年初级生产量和日最高初级生产量也有明显增加。作者以浮游植物群落的生态学变化作为主要指标,结合其他因素,对东湖的富营养化过程进行了生物学评价。并从环境保护角度,根据浅水湖泊在利用上的特点,提出了关于防治东湖这样一个多用途(供水、游览、渔业)的水体的富营养化的一些设想和建议。 相似文献
6.
威宁草海的浮游植物 总被引:1,自引:0,他引:1
从2004年1月至2005年1月,对贵州威宁草海的浮游植物进行采集和鉴定,共鉴定出浮游植物390种(含变型和变种),分属7门10纲23目41科96属。其中绿藻门种类最多,达205种,占总种数的52.56%;其次是蓝藻门的种类,有85种,占21.79%;硅藻门的种类有55种,占14.10%;其他藻类有45种,占11.15%。全年均能采集到的有60种,多数为小型的、富营养湖泊种常见的水华藻类,如铜绿微囊藻(Microcystis aeruginosa)、铜绿微囊藻小型变种(M. aeruginosa var. minor)。鉴定出的藻类植物种有105种为污染指示种,其中全年出现的多污性(ps)指示种有6种,β-多污性(β-ps)指示种有44种,α-中污性(α-ms) 指示种有78种,β-中污性(β-ms) 指示种有64种,寡污性(os) 指示种有17种,分别占总污染指示种总数的5.71%,41.90%、74.29%、60.95%、16.19%(有的种类具有多种污染级别的指示,在统计过程中均分别计算),草海的污染指示种以α-中污染和β-污染指示种为主。根据草海浮游植物种类组成的历史演变来看,硅藻门的种类减少较多,其他一些适宜生活于清洁水体种的藻类,如小黄丝藻(Heterotrichales minus)从1989年以后就未曾发现。所有结果都显示出草海已受到严重污染,属于富营养型的湖泊。 相似文献
7.
富营养化水体中N、P浓度对浮游植物生长繁殖速率和生物量的影响 总被引:20,自引:0,他引:20
在浮游植物生长繁殖的高峰期(7—10月份)对3个富营养化水体的总氮、总磷和浮游植物生物量进行调查,统计分析了生物量与氮和磷浓度的关系。利用3种水样和梯度稀释的东湖水样培养玫瑰拟衣藻(Chloromonas rosae),研究了氮、磷浓度对生长繁殖速率的影响。结果表明磷是生长繁殖速率的限制因子,求出了生长繁殖速率与磷浓度的对数回归方程y=0.08061nx+0.4658,当磷浓度小于0.05mg/L时,生长繁殖速率随着磷浓度的升高而直线上升,当磷浓度进一步升高,生长繁殖速率仍然随之增加,但增加的幅度越来越小,当磷浓度达到0.2mg/L时,生长繁殖速率基本不再随着磷浓度的增加而升高。计算出生长速率为零时磷的浓度是0.003mg/L,接近贫营养化湖泊磷浓度的下限,计算结果与坂本的调查统计结果相吻合,说明回归方程具有代表性。在凋查的3个富营养化水体中,浮游植物中的氮占全部氮元素的53%,磷占全部磷元素的85%,是氮、磷存在的主要形式,所以,评价水体的营养程度,必须同时考虑水中溶解的氮、磷和生物体内的氮、磷。统计分析表明,3个富营养化水体中浮游植物的生物量由氮(溶解氮+胞内氮)和磷(溶解磷+胞内磷)的浓度共同决定,生物量与氮浓度的直线回归方程y=10.687x-7.8304,生物量与磷浓度的直线回归方程y=122.11x-12.069。实验结果为根据氮、磷浓度以Redfield值判断浮游植物限制性营养元素的相对性和绝对性提供了例证。对3个富营养化水体的比较表明,防止水体富营养的唯一办法是维持水体氮、磷等主要营养元素收支平衡,治理富营养化的根本办法是从水体中移走过量的氮、磷等主要营养元素。 相似文献
8.
东海浮游植物数量分布与优势种 总被引:16,自引:0,他引:16
根据1997~2000年东海23°30′~33°N、118°30′~128°E海域4个季节海洋调查资料,运用定量、定性方法,探讨了东海浮游植物总丰度的平面分布、季节分布及变化的动力学机制,同时还探讨了东海浮游植物优势种的生态学特征和对温盐环境适应特征。结果表明:东海浮游植物总丰度有明显的季节分布,秋季总丰度达到4季最高峰,均值为211.91×104cell.m-3,夏季次之(50.40×104cell.m-3),冬季11.34×104cell.m-3,春季(2.01×104cel.lm-3)最低。春夏季东海近海(Ⅰ和Ⅲ)高于外海(Ⅱ和Ⅳ),秋冬季东海北部外海(Ⅱ)高于近海(Ⅰ),南部近海(Ⅲ)高于外海(Ⅳ)。4季共出现优势种(Y≥0.02)11种,冬季的主要优势种为洛氏角毛藻和细弱海链藻,春季的主要优势种为洛氏角毛藻和夜光藻,夏季以拟弯角毛藻和细长翼根管藻为主要优势种,秋季优势种仅为聚生角毛藻。浮游植物的聚集强度指数为较大正值,聚集作用明显。从全年的逐步回归分析结果看,温度是影响浮游植物总丰度季节分布的主要因子,盐度是次要因子。浮游植物的11个优势种之间生存环境适应比较,洛氏角毛藻和中华盒形藻生长温度幅度较大,可以在12~28℃水温增长,因而春、夏和冬季都成为优势种。中肋骨条藻适合生长的水温范围都较小,仅为22~28℃。聚生角毛藻更小,仅21~25℃。洛氏角毛藻和中华盒形藻生长温盐度和高分布区温盐度范围比聚生角毛藻和中肋骨条藻都广,而秋季数量却低于聚生角毛藻。 相似文献
9.
广东省典型水库浮游植物群落特征与富营养化研究 总被引:19,自引:6,他引:19
研究了广东省19座主要水库2000年丰水期和枯水期浮游植物状况,并根据浮游植物群落结构和多样性指数对水库进行营养状况评价。结果表明,东江流域的新丰江和白盘珠水库水质良好,属于贫营养型水库;大部分水库为中营养型,而鹤地、契爷石和石岩这3座位于沿海经济发达地区水库属于富营养型。流域上游水库水质明显优于下游水库,山区水库水质优于沿海水库,东江流域水库水质普遍较好。北江流域次之,而粤西沿海和珠江三角洲地区各水库均受到不同程度的污染。 相似文献
10.
淀山湖浮游植物优势种生态位 总被引:10,自引:0,他引:10
运用改进的Levins公式和Petraitis指数测定了淀山湖浮游植物优势种的生态位宽度和生态位重叠,分析了生态位宽度、种间生态位重叠与优势种密度和优势度的相关性.结果表明: 不同时期各优势种的生态位宽度和生态位重叠不尽相同,各物种对环境因子的适应能力存在差异.根据不同季节的生态位宽度可以将淀山湖浮游植物优势种分为4类;尖尾蓝隐藻和小球藻的生态位较宽,数量较多,分布较广,能充分利用环境资源.水华暴发时期,蓝藻门各优势种与其他藻类之间的生态位重叠程度相对偏高;铜绿微囊藻的生态位变宽,而其他优势种的生态位宽度相对有所降低.各季节优势种的优势度与其生态位宽度呈显著相关,优势种密度与生态位重叠呈极显著相关. 相似文献
11.
为了解生态调控后的浮游植物群落稳定性和优势种种间联结性,于2020年10月—2021年7月按季节对湖北长湖浮游植物群落进行调查。运用生态位宽度、生态位重叠值、方差比率法、卡方检验、Pearson相关性检验和Spearman相关性检验的方法对浮游植物优势种间的相互关系进行综合分析。结果显示:四季共鉴定出浮游植物8门、67属、78种;优势种19种。长湖属于绿藻+蓝藻+硅藻为主的水体。其中,梅尼小环藻(Cyclotella meneghiniana)和四尾栅藻(Scenedesmus quadricauda)为四季共有优势种,对水环境有较好的指示作用,显示长湖水体处于中度富营养化状态。根据优势度和生态位宽度的结果,19个优势种可以划分为4个类群。生态位重叠值的变化范围为0.02—0.96,季节差异明显,秋季>冬季>春季>夏季。方差比率的结果显示秋季和冬季浮游植物优势种间总体呈现显著正联结,群落较稳定;春夏季节优势种间总体呈现不显著负联结,群落处于波动状态。卡方检验、Pearson相关性检验和Spearman相关性检验结果综合显示:优势种对间联结性的显著率较低,群落种间联结不... 相似文献
12.
Long-term dynamics of phytoplankton assemblages: Microcystis-domination in Lake Taihu, a large shallow lake in China 总被引:40,自引:0,他引:40
Chen Yuwei; Qin Boqiang; Teubner Katrin; Dokulil Martin T. 《Journal of plankton research》2003,25(4):445-453
Long-term phytoplankton assemblages in a large shallow Chineselake, Lake Taihu, were presented using the monthly monitoringdata from October 1991 to December 1999. Earlier research results(1960, 1981 and 1988) were applied to discuss the differenttrophic stages of the lake. The species composition in the lakewas more closely related to eutrophication level than to lake-size,shallowness, or turbidity. Each summer, a single peak of phytoplanktonbiovolume appeared in Meiliang Bay. The results of principalcomponents analysis showed a distinct temporal shift in speciescomposition between summer and winter. A clear spatial differencein phytoplankton occurred between Meiliang Bay and the lakecentre. Wind speed and direction affected the horizontal distributionof phytoplankton, especially Microcystis, in the lake. Temperature,underwater light climate, nutrients and grazing by zooplanktonand by fish were discussed to explain the overwhelming dominanceof Microcystis. Four nutrient-phytoplankton stages were identifiedin the lake: an oligo-mesotrophic stage with low algal biomassuntil 1981, a eutrophic situation with blooms of Microcystisduring 19881995, hypertrophic conditions with the dominanceof Planctonema and total phosphorus up to 200 mg m-3 from 1996to 1997 and the restoration period after 1997. The wax and waneof the phytoplankton assemblages were mainly controlled by temperature,wind and turbidity while long-term biomass dynamics were influencedby the level of nutrients. 相似文献
13.
Sedimentation of nine phytoplankton species was studied in LakeConstance with the aid of sedimentation traps exposed at sixdifferent depths from 20 to 120 m. The study examines sedimentaryfluxes at all depths, temporal variation of sinking velocitiesinto the uppermost trap, annual averages of the sinking velocitiesat all depths and survival of algae during the sedimentationprocess. In spite of high intraspecific temporal variabilityof the sinking velocity there is a clear hierarchy from thepennate and the filamentous centric diatoms sinking the fastestto the Cryptomonads, nearly not at all affected by sedimentarylosses. Temporal variability of the sinking velocity withinspecies seems to be related to the physiological state,the highest velocities always occurring during stationary ordecline phases of the population development. An analysis ofthe role of sedimentary losses in the population dynamics ofAsterionella formosa, Fragilaria crotonensis, Stephanodiscusbinderaniss, Melosira granulata reveals positive correlationsbetween the sedimentation rate and cell mortality. 相似文献
14.
K. Takano Y. Ishikawa H. Mikami S. Ban T. Yoshida T. Aono K. Imada R. Yasutomi K. Takeuchi S. Hino 《Limnology》2001,2(1):29-35
The densities and growth rates of dominant phytoplankton in Lake Oshima-Ohnuma were determined during May to July 1996 to
clarify the mechanism of change from spring-dominant to summer-dominant phytoplankton species, examining the influence of
zooplankton grazing and nutrient limitation. The dominant phytoplankton in April and May were Asterionella gracillima and Nitzschia spp. Their growth rates were low in May and their densities fell thereafter. The bottle experiment suggests that the main
reason for decreases in dominant species has been nutrient deficiency, and zooplankton (sized from 30 to 160 μm) have supported
the growth of A. gracillima to recycle nutrients in May. The maximum growth rate was shown by Melosira (Aulacoseira) ambigua living at 2 m in May and June. Although the growth rate of the summer-dominant species Melosira (Aulacoseira) granulata was not as high as that of M. ambigua in May and June, the ambient density increased from late June. Survival in the lower zone of the unstratified euphotic layer
might have contributed to the abundance of M. granulata, since the growth rate of this species was not so low as that of M. ambigua at 6 m in June and July. The bottle experiment suggests that the growth of M. granulata was also nutrient limited in June and July and that zooplankton grazing was partially responsible for repressing the biomass
of M. granulata before it began growing rapidly in late June.
Received: January 31, 2000 / Accepted: September 6, 2000 相似文献
15.
Recently, large‐scale changes in the biogeography of calanoid copepod crustaceans have been detected in the northeastern North Atlantic Ocean and adjacent seas. Strong biogeographical shifts in all copepod assemblages were found with a northward extension of more than ° in latitude of warm‐water species associated with a decrease in the number of colder‐water species. These changes were attributed to regional increase in sea surface temperature. Here, we have extended these studies to examine long‐term changes in phytoplankton, zooplankton and salmon in relation to hydro‐meteorological forcing in the northeast Atlantic Ocean and adjacent seas. We found highly significant relationships between (1) long‐term changes in all three trophic levels, (2) sea surface temperature in the northeastern Atlantic, (3) Northern Hemisphere temperature and (4) the North Atlantic Oscillation. The similarities detected between plankton, salmon, temperature and hydro‐climatic parameters are also seen in their cyclical variability and in a stepwise shift that started after a pronounced increase in Northern Hemisphere Temperature anomalies at the end of the 1970s. All biological variables show a pronounced change which started after circa 1982 for euphausiids (decline), 1984 for the total abundance of small copepods (increase), 1986 for phytoplankton biomass (increase) and Calanus finmarchicus (decrease) and 1988 for salmon (decrease). This cascade of biological events led to an exceptional period, which is identified after 1986 to present and followed another shift in large‐scale hydro‐climatic variables and sea surface temperature. This regional temperature increase therefore appears to be an important parameter that is at present governing the dynamic equilibrium of northeast Atlantic pelagic ecosystems with possible consequences for biogeochemical processes and fisheries. 相似文献
16.
基于2003-2012年太湖竺山湖和西部沿岸区水体理化指标与浮游植物丰度的逐月监测数据,分析了两个湖区氮磷营养盐状态和浮游植物丰度以及浮游植物主要类群的年际变化趋势及季节变化特征,探讨了浮游植物群落变化与水温及营养盐指标间的关系。结果表明:10年间两个湖区氮磷营养盐浓度总体呈下降趋势,以竺山湖TN、NH3-N浓度和西部沿岸区NO3-N浓度下降最为显著;浮游植物丰度总体呈上升趋势,蓝藻在群落结构中日益占据绝对优势;季节变化上,氮营养盐浓度表现为春冬季节高于夏秋季节,TP浓度和浮游植物丰度呈相反的变化趋势。Pearson相关分析显示,水温、NH3-N浓度和TN/TP是影响蓝藻丰度及其在浮游植物群落中所占比例的主要因素。在温度和营养盐结构的共同作用下,10年间两个湖区蓝藻水华暴发时间逐渐提前,而消退时间逐渐滞后,水华持续时间逐年上升。在全球变暖背景下,太湖水华治理需执行更加严格的氮磷限制阈值,且在重污染的西北湖区控磷依然是关键。 相似文献
17.
The spring development of phytoplankton in Lake Erken 总被引:1,自引:0,他引:1
SUMMARY. In Lake Erken there is a regular phytoplankton peak at ice-breakup in the spring. Pechlaner (1970) studied the spring outburst of 1960. We carried out a similar study in 1973, when the climatic factors were completely different, with only 10 cm of ice and almost no snow. Thus, due to light penetration, there was a high phytoplankton biomass under the ice as early as March.
Stephanodiscus astraea (Ehr.) Grun. and Asterionella formosa Hass. dominated the biomass during the spring development in 1973 instead of the normally dominating S. hantzschii v. pusillus Grun.
The nutrient decrease was slower in 1973 than in 1960. A comparison of carbon assimilation and the decrease of nitrate and phosphate indicate sufficient nutrient supply in 1973. In 1960, the population grew logarithmically until the nutrients became limiting. In 1973, the average biomass was greater, but the mean probable primary production was only half that of 1960. From the activity coefficients for the 2 years it is also clear that, in 1960, S. hantzschii v. pusillus was highly productive during its short but intensive growth period. Its minute size and high surface/volume ratio enabled it to take up nutrients rapidly and efficiently. The chlorophyll content of S. astraea in 1973 was only half as much as that of S. hantzschii v. pusillus in 1960. Since the light conditions under the ice in March 1973 were more unfavourable than during the exponential phase of 1960, production was much lower. 相似文献
Stephanodiscus astraea (Ehr.) Grun. and Asterionella formosa Hass. dominated the biomass during the spring development in 1973 instead of the normally dominating S. hantzschii v. pusillus Grun.
The nutrient decrease was slower in 1973 than in 1960. A comparison of carbon assimilation and the decrease of nitrate and phosphate indicate sufficient nutrient supply in 1973. In 1960, the population grew logarithmically until the nutrients became limiting. In 1973, the average biomass was greater, but the mean probable primary production was only half that of 1960. From the activity coefficients for the 2 years it is also clear that, in 1960, S. hantzschii v. pusillus was highly productive during its short but intensive growth period. Its minute size and high surface/volume ratio enabled it to take up nutrients rapidly and efficiently. The chlorophyll content of S. astraea in 1973 was only half as much as that of S. hantzschii v. pusillus in 1960. Since the light conditions under the ice in March 1973 were more unfavourable than during the exponential phase of 1960, production was much lower. 相似文献
18.
Specific absorption coefficient and the phytoplankton package effect in Lake Taihu,China 总被引:5,自引:0,他引:5
In order to investigate variations of absorption and total chlorophyll-a (TChl-a)-specific absorption coefficient of phytoplankton in Lake Taihu, 57 water samples obtained from Lake Taihu during November
8–22, 2007 were used in this study. Package effect and accessory pigments’ influences on the absorption spectra were also
examined. Phytoplankton absorption was measured by quality filter technical, and TChl-a concentration was measured by “hot ethanol” method. Results yielded significant variations in phytoplankton absorption and
TChl-a-specific absorption coefficient. Phytoplankton absorption coefficient at 675 nm is highly correlated to TChl-a concentration, while absorption at 440 nm is less correlated to TChl-a concentration because of great package effect and accessory pigments’ influence. There was an inverse relationship between
a
ph*(λ) and TChl-a concentration. Four types of absorption spectra are identified by normalizing a
ph*(λ) to a
ph*(440). The a
ph*(λ) variation is mainly due to accessory pigments and package effect, whose influence at 675 nm ranges from 83.2% to 28%,
with an average of 65.3%. Meanwhile, the wide varying ratio of a
ph*(440) to a
ph*(675) indicates a large variation range in the ratio of accessory pigment to TChl-a concentration. Those findings are significant to estimate Chl-a concentration based on bio-optical model, estimate primary production from remote sensing, and plan further ecological restoration
measures for Lake Taihu.
Handling editor: Luigi Naselli-Flores 相似文献
19.
太湖梅梁湾浮游植物叶绿素a和初级生产力 总被引:23,自引:0,他引:23
1998年5月~1999年8月对太湖梅梁湾4站点进行了每季1次、为期1年的初级生产力及相关因子研究,分析了梅梁湾叶绿素a含量和初级生产力的时空分布特征.结果表明,梅梁湾的叶绿素a含量、初级生产力均存在明显的季节变化和空间差异,春、夏季浮游植物叶绿索a含量和初级生产力要比秋、冬季高,空间上位于污染严重的直湖港口6#点叶绿索a含量和初级生产力要高,并大致呈现从湾内向湾口递减的趋势;在春、夏、秋季光照较强时,初级生产力最大指值出现在水下20~50cm处。到冬季垂直差异不明显;10~30℃之间初级生产力基本上随温度的上升而呈指数增加趋势.浮游植物生物现存量与初级生产力存在显著的正相关.营养盐与初级生产力相关性变化很大.光照显著地影响初级生产力的日变化。春、夏季强光作用下表面光抑制现象比较明显. 相似文献
20.
The effect that climate change in the Lake Baikal region has on the state of the lake plankton is discussed. The increase in water temperature in the photic layer and chlorophyll a content during direct stratification is demonstrated with the use of a database containing the results of plankton observations from 1951 to 2000. The number of small-cell algae belonging to the summer complex seems to increase, while the number of endemic large cell algae developing under the ice is characterized by negative trends. 相似文献