万峰湖浮游植物群落的时空分布

于2009年9月(夏季)和2010年1月(冬季)对万峰湖(水库)的浮游植物群落结构时空分布特征进行研究.在万峰湖共监测到浮游植物49种,其中夏季水库表层(0-10 m)浮游植物优势种为蓝藻门中的拟柱孢藻(Cylindrospermopsis rackiborskii),底层为硅藻门中肘状针杆藻(Synedra ulna)和梅尼小环藻(Cyclotella meneghiniana);在冬季以硅藻门中的小环藻(Cyclotella sp.)和梅尼小环藻为主.夏季,浮游植物表层丰度为13.0×104～54.6×104 cells·L-1,野鸭滩(S2)最高,而以坝艾(S4)浮游植物丰度最低;浮游植物主要集中在表层(0～10 m),以蓝藻组成为主,蓝藻丰度百分数在大坝(S1)最高,达到90.3%,香浓多样性指数夏季高于冬季,夏季表层均匀度指数最低.冬季,浮游植物丰度为17.43×104～25.28×104 cells·L-1,浮游植物主要集中在表层(0～10 m)和中层(10～50 m),水体的各层硅藻所占比例均在90%以上.从浮游植物群落结构和丰度看,万峰湖处于中营养状态,冬季水质好于夏季.夏冬两季浮游植物丰度与水体的温度及水深都表现出了较强的相关关系.     

喀斯特高原深水水库-万峰湖富营养化特征分析

以贵州喀斯特高原深水水库-万峰湖为例,研究了其夏季和冬季湖沼学和富营养化特征。结果表明:冬季和夏季湖沼学及富营养化特征区别明显,夏季水温,pH值,溶解氧,电导率等指标在10 m和30 m分别出现明显的分界点,而冬季仅在30 m出现分界点,表明夏季属于双分层型,冬季属于单分层型。表层和底层的水温变化幅度较小,底层温度较高,在10℃以上;底层全年处于厌氧状态,钙离子浓度在0.192~0.235 mg/L 之间,镁离子的浓度在0.149~0.196 mg/L 之间,但是垂直和季节变化较小。总磷浓度在0~40 m较低,在0.02~0.04 mg/L之间,底层达0.794 mg/L;总氮浓度在0~40 m维持在2.18~3.54 mg/L,夏季略高于冬季,总氮浓度随深度逐渐降低。根据单因子指数判断,万峰湖大多时期属于中富营养状态。万峰湖不同季节的分层特征,反映出了喀斯特高原深水水库湖沼学变化特征,水体分层影响着水环境因子的变化和水体富营养化程度。     

大沙河水库冬季浮游植物群落结构与水华分析

于2009年12月、2010年1月和2月对广东省大沙河水库湖泊区距水表层0.5m、5m和10m三个水层的浮游植物进行了定性与定量分析,同时对环境变量进行了测定.采样期间三个月的总降雨量为263mm,水温范围在15.5～19.4℃之间,水体处于混合状态.三次采样中,共检测出浮游植物69种(属),隶属于6个门,浮游植物丰度范围在4.1×10⁶～14.8×10⁶cells·L^-1之间.三个水层的浮游植物优势种类差异不显著(p>0.05),丰度的主要优势种为蓝藻门的卷曲鱼腥藻(Anabaena circinalis)、铜绿微囊藻(Microcystis aeruginosa),这两个种的丰度之和占总丰度的70%以上,在2009年12月和2010年2月的表层出现了轻度鱼腥藻和微囊藻水华.蓝藻自身的浮力调节机制和适应低磷的生活策略是其成为优势种的重要原因,相对稳定的外部条件、水体混合与富营养共同导致的光的可获得性的减少是形成蓝藻水华的关键外部因子.     

巢湖夏、秋季浮游植物叶绿素a及蓝藻水华影响因素分析

2007年6-11月份,对设置在巢湖全湖的23个样点水体的理化指标水温(WT)、pH值、溶解氧(DO)、总氮(TN)、总磷(TP)、活性磷(RP)以及浮游植物的种类组成和叶绿素a(Chl-a)浓度进行了调查分析。结果表明:在巢湖夏秋季温差变化不大的环境中,温度依然是影响藻类生物量的重要因素。夏、秋季蓝藻为最主要的藻类类群(其平均值占藻类总生物量的63.36%);藻类生物量与所测理化因子均有显著正相关。在夏、秋季各月份,蓝藻生物量呈前高后低状M型波动,其中7月份湖水中蓝藻浓度最低。夏、秋季湖水中叶绿素的浓度没有太大变化,维持在一个较高的水平(>10mg/m3),遇到合适的气象条件有形成大面积水华的可能。     

淀山湖蓝藻季节动态及其影响因子

为了掌握淀山湖蓝藻门浮游植物群落及其与环境因子的关系,于2009年5月—2010年4月在全湖选取9个点位对浮游植物群落进行了调查,应用CANOCO4.5软件对获得的蓝藻门种类和环境因子数据进行典范对应分析(CCA),并绘制了物种与环境因子关系的二维排序图。结果表明:调查期间共出现蓝藻门15属46种,微囊藻属占69.9%,其次颤藻属占20.5%;蓝藻数量分布具有明显的季节性,密度变化范围为9.0×104～7.6×106 cells·L-1,蓝藻细胞密度与叶绿素a、总氮、营养状态指数TSIM(chl-a)和TSIM(TN)相关性较好,表明总氮浓度对蓝藻细胞密度影响较大,而密度和相对丰度影响着湖泊中的叶绿素含量和透明度等;CCA分析表明,春季水体受水温、生物需氧量、总磷影响较大,夏季水体受总磷、BOD5、透明度影响较大,秋季环境因子影响类型较为集中但不显著,冬季各环境因子影响较夏、秋两季明显,水体与铵态氮、透明度(SD)均呈正相关;分析了蓝藻中作为全湖优势种类的铜绿微囊藻和弱细颤藻与环境因子之间的关系,前者与水温、总氮呈显著正相关,与pH值呈现负相关;后者四季均有出现,数量变化受水温影响最大,在夏季与较低的pH值有关;环境因子改变与蓝藻季节演替内在联系表现为蓝藻群落在春冬2季受水温影响最大,夏季受TP、TN影响显著,秋季则与水体的透明度相关性最大。本实验对于理解淀山湖蓝藻优势种季节演替特征及对其开展监测治理具有指导意义。     

蓄水对三峡库区重庆段长江干流浮游植物群落结构的影响

为了分析三峡库区长江干流重庆段因蓄水产生的三类不同水体(自然河流型、过渡型、类湖泊型)对浮游植物的影响,分别于不同季节和蓄水期对水体浮游植物进行了群落调查,结果显示各群落指标仍呈现亚热带河流型水库的季节变化趋势:春季绿藻、隐藻占优势,夏季蓝藻所占比例增加,冬季硅藻占绝对优势,但不同类型水体对季节的响应程度不同:(1)2010年3月春季调查期间绿藻的优势种的优势度以及所占比例均呈现随水体类型改变逐渐增加趋势,并在类湖泊型水体中达到最大(优势度0.62、所占比例达67.8%),而夏秋季(9月蓄水前)蓝藻的优势种数、优势度、藻密度以及所占比例也存在同样的变化,2009年9月蓝藻所占比例由河流型水体的8.5%增加到类湖泊型水体的52.6%,到2010年9月类湖泊型水体蓝藻比例甚至达到63.8%。冬季蓄水期间(2010年1月),硅藻占绝对优势,但绿藻在类湖泊型水体中的比例要大于其他两类型水体。(2)Shannon-Wiener指数平均值为2.43,总体呈现出河流型水体>过渡型水体>类湖泊型水体,类湖泊型水体多样性指数夏秋季>冬季>春季,而自然河流型和过渡型水体冬季多样性指数低于其他季节。     

东印度洋赤道南北两侧春季活体浮游有孔虫的组成与分布

2017年3月通过对在东印度洋海区6个站位53个垂直分层拖网浮游有孔虫样品进行的定量分析,探讨了该海区春季现代浮游有孔虫的组成、分布及其影响因素。东印度洋春季0～3 000m水层内共鉴定出17个浮游有孔虫属种,主要是Globigerinoides ruber,Globorotaloides hexagona,Globigerinoides sacculifer,Globigerinella aequilateralis,Neogloboquadrina dutertrei,Globorotalia menardii,Globiberinella calida,Pulleniatina obliquiloculata和Globorotalia theyeri等,它们是典型的热带亚热带暖水种浮游有孔虫群落。G.ruber,G.sacculifer最大丰度层在0～50m水层;G.conglomerata,G.hexagona最大丰度层均出现在50～100m;G.theyeris在100～1 000m间的水层均有活体出现,100～150m水层中该种浮游有孔虫丰度最高;G.scitula为深层水浮游有孔虫分子,主要出现于300～2 000m的深水水层。东印度洋春季浮游有孔虫群落的丰度在赤道中心区最低,由赤道向南北两侧扩展,其丰度逐渐递增的特点。浮游有孔虫丰度明显呈上层高,下层低的特点,在50～100m水层浮游有孔虫丰度最高,明显高于0～50m水层浮游的有孔虫丰度,这与印度洋50～100m水体中叶绿素最大值层相对应,表明浮游有孔虫受水体初级生产力影响明显。     

南淝河叶绿素 a 时空分布特征及环境因子影响分析简

2009年8月至2012年4月,采样测试了南淝河上游8个位点的水质状况等,分析了南淝河叶绿素a(Chl.a)的时空分布特点及其与环境因子的关系。结果表明,南淝河研究河段Chl.a平均值为83.46μg/L,已处于严重富营养化状态。南淝河Chl.a浓度与总磷(TP)、化学需氧量(COD)、酸碱度(pH)、总固体悬浮物(TSS)、水温(WT)显著性正相关(P0.05),与透明度(SD)、氨氮/总磷比值(4NH+–N/TP)、水深(WD)、降雨(Rain)及风速(Wind)显著性负相关(P0.05)。逐步回归分析表明,影响南淝河上游河段Chl.a浓度的主导环境因子依次为水温、风速、降雨、总磷和氨氮。对南淝河与其他富营养化水体Chl.a的主要影响因子进行比较,结果表明水温是影响Chl.a的最重要因子,氮磷比、营养盐、降雨、风速、生物因子均对富营养化水体Chl.a有影响。     

贵州红枫湖水体叶绿素a的分布与磷循环

于2009年8月(夏季)和2010年1月(冬季)在贵州红枫湖采集了分层湖水和分层沉积物样品,分析了湖水样品的总N(TN)、总P(TP)及叶绿素a(Chl-a)含量,结果表明,湖水TN含量在2个季节无明显变化,平均含量为1.58±0.73 mg·L-1,湖水TP含量夏季(0.091±0.070 mg·L-1)高于冬季(0.026±0.055 mg·L-1).夏季湖水在8 m处有季节性分层,下层湖水TN、TP含量高于上层;夏季湖水Chl-a主要集中在上层,上层平均含量为33.2±13.0 mg·m-3,冬季湖水Chl-a平均含量为11.1±3.7 mg·m-3,分析发现,湖水上层(8 m)Chl-a与TP有明显的线性相关关系(r=0.965,P＜0.01),表明红枫湖富营养化主要受P元素限制.沉积物孔隙水中的溶解态P(DP)浓度和湖水的磷酸盐(PO3-4-P)浓度比上覆水体高,具有向上扩散的趋势,利用费克第一定律计算了沉积物向上覆水体的释P速率,发现夏季沉积物向上覆水体释P速率高于冬季,可能主要是由于夏季湖水底层的还原环境下沉积物表层的早期成岩作用生成磷酸盐进入孔隙水而促进了沉积物向上覆水体释放P.根据通量释放结果估算了全湖沉积物向水体的释P通量,约为每年5.0±5.6 t.红枫湖富营养化受P控制,沉积物向水体有很大的释放P的潜力,是湖水P的重要内源,严格控制流域的外源输入才能彻底治理该湖的富营养化.     

南淝河叶绿素a时空分布特征及环境因子影响分析

2009年8月至2012年4月,采样测试了南淝河上游8个位点的水质状况等,分析了南淝河叶绿素a(Chl.a)的时空分布特点及其与环境因子的关系。结果表明,南淝河研究河段Chl.a平均值为83.46μg/L,已处于严重富营养化状态。南淝河Chl.a浓度与总磷(TP)、化学需氧量(COD)、酸碱度(pH)、总固体悬浮物(TSS)、水温(WT)显著性正相关(P0.05),与透明度(SD)、氨氮/总磷比值(4NH+–N/TP)、水深(WD)、降雨(Rain)及风速(Wind)显著性负相关(P0.05)。逐步回归分析表明,影响南淝河上游河段Chl.a浓度的主导环境因子依次为水温、风速、降雨、总磷和氨氮。对南淝河与其他富营养化水体Chl.a的主要影响因子进行比较,结果表明水温是影响Chl.a的最重要因子,氮磷比、营养盐、降雨、风速、生物因子均对富营养化水体Chl.a有影响。     

Seasonal change in the locomotor activity rhythm of the medaka,Oryzias latipes

A group of the medaka,Oryzias latipes (Cyprinodontidae, orange-red variety, 25 males and 25 females), was kept in an aquarium, which was placed outdoors under natural conditions from December 1984 to January 1986. Locomotor activity at three layers (upper, middle, and lower layers) was recorded with a phototransistor system in each season. In summer, the fish showed typical diurnal activity at all three layers and the activity was greater than in other seasons. However, in autumn and winter, the fish became less active and showed relatively high activity at night at the upper or middle layer and diurnal activity at the lower layer. Nocturnal activity seemed to appear when the water temperature was decreased and the photoperiod was shortened. A free-running activity rhythm was also recorded under continuous darkness (DD) in each season; however, the fish showed clear free-running activity rhythms under DD only in summer.     

麦田沟金针虫种群垂直分布与夏眠的生态特性及其与防治的关系

麦田沟金针虫种群垂直分布与夏眠的生态特性及其与防治的关系罗益镇,牛赡光,龙岩（山东省农科院植保所,济南２５０１００）（山东省膝州市植保站,２７７５００）ＥｃｏｌｏｇｉｃａｌＣｈａｒａｃｔｅｒｓｏｆＶｅｒｔｉｃａｌＤｉｓｔｒｉｂｕｔｉｏｎａｎｄＡｅｓｔ...     

Causal analysis of the diversity of medusae in East China Sea

Based on the maritime data collected from 23°30'-33°00' N and 118°30'-128°00' E of the East China Sea (ECS) in four seasons during 1997-2000,the dynamics of medusae diversity and their causes were ana-lyzed.A total of 103 medusae species were identified,and these species mainly distributed in the southern and north-ern offshore areas of the ECS.Species diversity index (H') of medusae was higher in the south than those in the north,higher in summer and winter than in spring and autumn,and higher in offshore than in the nearshore areas.The species number was closely correlated with H' value,whereas the abundance of species had no significant rela-tionship with the diversity index.The lower H' value of the nearshore in spring and autumn resulted from the aggrega-tion of Muggiaea atlantica in the south nearshore and Diphyes chamissonis in the north nearshore.In addition,water temperature,followed by salinity,is the main envir-onmental factor influencing the distribution of species diversity.The H' value was related to the water temperature at the 10 m layer in winter and spring,and it was associated with the surface water temperature in summer and with the 10 m-salinity-layer in autumn.In spring and summer,the isoline distribution of H' value reflected the direction of the Taiwan Warm Current and the variation of the water masses in the ECS.In winter,the isoline of the H' value indicated the incursion of Kuroshio current.In conclusion,the H' isoline is an good indicator for water masses in ECS.     

Population structure and reproduction ofCalanus helgolandicus (Copepoda,Calanoida) along the iberian and Moroccan slope

During three cruises, carried out in March 1991, October 1991, and January 1992 off the Iberian Peninsula and Morocco, the abundant calanoid copepodCalanus helgolandicus (Claus) was collected from a depth of 1000 m to the surface. Differences in depth preference were correlated with the life stage and geographically differing vertical salinity structures. In autumn and winter, only stage V copepodids (CV) and adults were found, in spring also younger copepodid stages. Within the range of the Mediterranean outflow water (MOW), a sharp decline of abundances of all stages was evident during all cruises. In autumn 1991, the bulk of the population was recorded south of the MOW, in winter 1992 north of it. During winter, numbers had declined by 70%, supporting the idea that winter individuals represent the same generation as was encountered in autumn, and that they had been transported northwards. CV stages preferred the depth layer 400–800 m, in autumn and winter. Adults were found in autumn at the same depth south of the MOW, while they preferred the 0–400 m layers north of it. In winter, the abundance of adults increased, males preferred the 400–600 m depth layer, while females stayed at 200–400 m. In spring 1991, stages younger than CV were found in high densities, all stages concentrating in the upper 200 m. During the crosslope survey in spring off Portugal, an absolute abundance maximum of females was found. In contrast, offshore densities were very low. On the basis of these findings, the hypothesis of a Mediterranean centre of distribution and dispersal into the Atlantic is questioned. It is suggested that a separate, reproductively active population ofC. helgolandicus exists off NW. Africa.     

Some generalizations based on stratification and vertical mixing in meromictic Lake Shira,Russia, in the period 2002–2009

In a brackish, temperate, 24-m-deep Lake Shira, the profiles of salinity, temperature, oxygen and sulfide concentrations were measured on a seasonal basis from 2002 to 2009. The lake was shown to be meromictic with autumnal overturn restricted to mixolimnion. The depth of mixolimnion and position of oxic–anoxic interface varied annually. The spring mixing processes contribute to the formation of mixolimnion in autumn. The exceptionally windy spring of 2007 caused the deepening of mixolimnion in the winter of 2008. The winter position of oxic–anoxic interface was affected by the position of lower boundary of mixolimnion in all winters. The salinity in the winter mixolimnion increased compared with the autumn because of freezing out of salts from the upper water layers meters during ice formation and their dissolution in water below. The profiles of salinity and temperature were simulated by the mathematical 1-D model of temperature and salinity conditions taking into account ice formation. The simulated profiles generally coincided with the measured ones. The coincidence implies that simplified one-dimensional model can be applied to roughly describe salinity and density profiles and mixing behavior of Lake Shira.     

毛乌素沙地沙丘土壤含水量特点——兼论老固定沙地上油蒿衰退原因

土壤表面干沙层在冬春少雨季节较厚,流动沙地的又明显地大于固和地的。流动沙地地表干沙层以下的土壤含水量一般在于同深化度固定沙地的,特别是在报系密集分布的土层。科季或早春土壤含水量比较低,雨季的明显较高,雨季结束后,土层中的水分在重力的作用下会向深层运动,导致根系层土壤含水量下降。在植物生长季,缺少降雨时,因少地的土土壤水量会因植物的蒸腾消耗而变得很低（１％～２％）,而流动沙地的不受或受此影响很小。地     

The association of Antarctic krill Euphausia superba with the under-ice habitat

The association of Antarctic krill Euphausia superba with the under-ice habitat was investigated in the Lazarev Sea (Southern Ocean) during austral summer, autumn and winter. Data were obtained using novel Surface and Under Ice Trawls (SUIT), which sampled the 0-2 m surface layer both under sea ice and in open water. Average surface layer densities ranged between 0.8 individuals m(-2) in summer and autumn, and 2.7 individuals m(-2) in winter. In summer, under-ice densities of Antarctic krill were significantly higher than in open waters. In autumn, the opposite pattern was observed. Under winter sea ice, densities were often low, but repeatedly far exceeded summer and autumn maxima. Statistical models showed that during summer high densities of Antarctic krill in the 0-2 m layer were associated with high ice coverage and shallow mixed layer depths, among other factors. In autumn and winter, density was related to hydrographical parameters. Average under-ice densities from the 0-2 m layer were higher than corresponding values from the 0-200 m layer collected with Rectangular Midwater Trawls (RMT) in summer. In winter, under-ice densities far surpassed maximum 0-200 m densities on several occasions. This indicates that the importance of the ice-water interface layer may be under-estimated by the pelagic nets and sonars commonly used to estimate the population size of Antarctic krill for management purposes, due to their limited ability to sample this habitat. Our results provide evidence for an almost year-round association of Antarctic krill with the under-ice habitat, hundreds of kilometres into the ice-covered area of the Lazarev Sea. Local concentrations of postlarval Antarctic krill under winter sea ice suggest that sea ice biota are important for their winter survival. These findings emphasise the susceptibility of an ecological key species to changing sea ice habitats, suggesting potential ramifications on Antarctic ecosystems induced by climate change.     

疏勒河源高寒草甸土壤微生物生物量碳氮变化特征

土壤微生物生物量是土壤有机质的活性部分,是反映土壤质量和碳氮循环机制的重要指标。本文以青藏高原东北缘疏勒河源高寒草甸为研究对象,对土壤微生物生物量碳（SMBC, mg/kg）和微生物生物量氮（SMBN, mg/kg）的不同季节（春、夏、秋、冬）和土层（0—10、10—20、20—30、30—40、40—50 cm）变化特征及其影响因素进行研究。结果表明：（1）不同土层SMBC均表现为春季开始逐渐升高、夏季达到最大值、秋季逐渐降低、冬季值最小,而SMBN春季开始逐渐降低、夏季值最小、秋季逐渐升高、冬季达到最大值。（2）SMBC、SMBN随着土壤深度的增加而下降,0—10 cm层SMBC、SMBN显著高于40—50 cm层,且SMBC、SMBN0—10 cm层的季节变幅显著大于40—50 cm层。（3）0—50 cm土层SMBC/SMBN表现为春季开始逐渐升高、夏季达到最大值、秋季逐渐降低、冬季值最小,其季节变化范围为8.77—23.59,处于较高水平。（4）SMBC、SMBN、SMBC/SMBN的季节和土层变化主要受植被地下生物量和土壤温度的影响。（5）各土层SMBC/SOC均表现为春季开始逐渐升高、夏季达到最大值、秋季逐渐降低、冬季值最小,而SMBN/TN春季开始逐渐降低、夏季值最小、秋季逐渐升高、冬季达到最大值。除夏季土层间无显著差异外,SMBC/SOC与SMBN/TN均表现为0—10 cm层显著高于40—50 cm层。（6）0—50 cm土层SMBC/SOC夏秋季显著高于冬春季且其季节变化范围为0.58%—1.18%,而SMBN/TN秋冬季显著高于夏季且其季节变化范围为0.39%—0.72%。综上,季节变化和剖面深度均对SMBC、SMBN产生显著影响且0—10 cm土层对SMBC、SMBN的累积能力最强。     

Anoxia in a coastal bay: case study of a seasonal event

Bahía Concepción (Gulf of California) was studied to describe some extremely low dissolved-oxygen values at the bottom of the bay. Surveys included measurements of vertical distribution of temperature, dissolved oxygen, nitrate, nitrite, phosphates and hydrogen sulfide. Thermal stratification from early spring to autumn and a well-mixed water column during the winter were present. Dissolved-oxygen concentration was homogeneous in the water column from winter to spring (5-7 mg L-1). From summer to autumn, bottom dissolved oxygen (> 20 m) decreased to reach conditions of hypoxia (1-2 mg L-1) or anoxia; nitrate, nitrite, and phosphates increased (up to 13, 1.7 and 2.2 microM) followed by a last short period of a deep hydrogen sulfide layer (up to 3.1 mg L-1). A back calculation to estimate the input of organic matter in the deep layer showed that 18 g C m-2 y-1 needed to be trapped in the bottom to induce such an oxygen depletion. This period is thought to be unfavorable for bottom infauna in this bay.     

春季和秋季东海陆架区浮游纤毛虫的丰度和生物量

于2011年春季(5月)和秋季(11月)在东海陆架区进行浮游纤毛虫丰度和生物量的调查.春季和秋季纤毛虫的平均丰度分别为(614±861)和(934±809) ind·L^-1,平均生物量分别为(1.70±3.91)和(0.93±0.99) μg C·L^-1.表层纤毛虫丰度和生物量的高值区春季主要分布在近岸及远岸海区,秋季主要分布在远岸海区.春季纤毛虫的丰度和生物量在水体上层较高;秋季纤毛虫主要分布在水体上层,有时在水体底层也会出现丰度和生物量的高值.春季无壳纤毛虫群落的粒级较大,秋季较小.砂壳纤毛虫占纤毛虫丰度的平均比例春季和秋季分别为(26.9±34.3)%和(44.9±25.2)%.两个季节共鉴定出砂壳纤毛虫27属52种,春季丰度较大的种为原始筒壳虫、橄榄领细壳虫及筒状拟铃虫,秋季丰度较大的种为原始筒壳虫、小领细壳虫及矮小拟铃虫.纤毛虫丰度与温度、叶绿素a(Chl a)浓度呈显著正相关.砂壳纤毛虫丰度与盐度呈显著负相关,群落结构变化与温度显著相关.