珠海横琴岛海域浮游动物群落结构特征

根据2013 年11 月(秋季)、2014 年5 月(春季)、2015 年2 月(冬季)和8 月(夏季)4 航次的调查数据, 对横琴岛海域浮游动物物种组成、时空分布及多样性等群落结构特征进行了分析。结果显示: 共鉴定出浮游动物103 种类, 阶段性浮游幼体13 类, 桡足类种类最多42 种, 其次为刺胞动物18 种。种类数秋季最多52 种, 夏季次之50 种, 冬季最少46 种。年均丰度范围为100.31-2003.90 ind·m^–3, 均值为606.22 ind·m–3; 年均生物量范围56.30-137.13 mg·m^–3, 均值为80.86 mg·m^–3; 该海域优势种更替较快, 其优势种春季为刺尾纺锤水蚤Acartia spinicauda、中华异水蚤Acartiella sinensis 等5 种, 夏季为短角长腹剑水蚤Oithona brevicornis 和强额孔雀哲水蚤Pavocalanus crassirostris, 秋季为长尾类幼体Macrura larvae、亚强次真哲水蚤Eucalanus subcrassus 等8 种, 冬季仅夜光虫Noctiluca scintillans 一种。多样性指数、均匀度指数、多样性阈值及丰富度指数均值春季为3.86、0.88、3.40、3.24, 夏季为2.10、0.89、1.88、1.01, 秋季为3.34、0.83、2.78、2.63, 冬季为0.95、0.31、0.30、0.09。其中冬季4 项指数均很低, 表明该海域浮游动物群落结构异常, 海域生态环境受到了一定程度的污染破坏。     

烟台四十里湾浮游动物群落特征及与环境因子的关系

2009年3月—2010年12月在烟台四十里湾海域对浮游动物群落结构及其环境因子进行了连续20个航次的综合调查,记录到浮游动物8大类共计64种(类)。浮游动物主要类群为桡足类和浮游幼虫,分别发现22种、18类,占总种(类)数34%、28%;其次为水螅水母类,发现13种,占20%;毛颚动物和栉水母类各发现1种。浮游动物的优势种为中华哲水蚤(Y=0.183)、腹针胸刺水蚤(Y=0.078)、强壮箭虫(Y=0.078)和洪氏纺锤水蚤(Y=0.026)。浮游动物的生态类型主要为温带近岸种和广布性种。四十里湾海域浮游动物群落结构的季节变化较为明显,春、夏、秋、冬四季之间群落结构有显著性差异(P0.05),同一季节内群落结构相似度较高,达55%以上。浮游动物丰度中位值在5月份达到最高(546.3个/m~3);种类数、多样性指数中位值均在8月达到最高,分别为18种、3.20;浮游动物生物量呈现出双峰变化模型,5月份达到第1峰值(中位值870.4 mg/m~3),10月份为第2峰值(中位值362.0 mg/m~3)。浮游动物种类数高值区主要分布在养马岛北部海域,而丰度高值区主要分布在近岸尤其是辛安河口海域。浮游动物种类数及多样性指数与水温、化学需氧量、硅酸盐显著正相关(P0.01),与盐度、溶解氧、无机氮显著负相关(P0.01);水温和盐度是影响浮游动物分布的主要环境因子,其次是硅酸盐、叶绿素a和化学需氧量,活性磷酸盐、溶解氧、透明度以及无机氮对浮游动物分布的影响较小。     

南汇东滩湿地围垦水域内浮游动物群落结构的变化

2010年10月-2011年7月对南汇东滩围垦水域和坝外自然水域的浮游动物进行调查,研究了两水域内浮游动物的种类组成、丰度、生物量、优势种和生物多样性等生态学特征参数的季节变化,并初步探讨了围垦内外水域浮游动物群落的结构差异,及其与盐度、水温和人类活动等环境因子的关系.结果表明:围垦水域和坝外自然水域共检获浮游动物30种,其中围垦水域浮游动物24种,以轮虫的种类数最多;坝外自然水域浮游动物14种,其中桡足类占绝对优势.围垦水域浮游动物的年平均丰度明显高于坝外自然水域,年平均生物量则相反.围垦水域以角突臂尾轮虫、萼花臂尾轮虫和广布中剑水蚤等淡水种为主要优势种,而坝外自然水域则以中华华哲水蚤、火腿许水蚤和虫肢歪水蚤等河口半咸水种为主要优势种,且两水域优势种均存在季节更替.坝外水域浮游动物Shannon多样性指数(H)值和Pielou均匀度指数(J)值均明显高于围垦水域,Margalef丰富度指数(d)值和单纯度指数(C)值低于围垦水域.群落聚类和MDS结果表明,围垦水域浮游动物的群落结构与坝外自然水域存在明显差异.围垦是引起被围水域浮游动物群落结构变化的主要原因,盐度、潮汐动力等是导致动物群落结构改变的主要环境因子.     

东山湾及其邻近海域游泳动物多样性的分析

根据2009年11月至2010年8月在东山湾及其邻近海域的调查资料,统计渔获物物种组成,计算该海域各物种的相对重要性指数(IRI)、相对资源密度、Margalef种类丰富度指数、Shannon-Weiner种类多样性指数以及Pielou均匀度指数,并分析其时空分布特征。结果表明,东山湾及其邻近海域的物种组成比例与台湾海峡大体一致。秋冬春夏4个季度优势种种类数均较少,分别为4、2、1、3种,且季节更替明显。不同季节多样性指数表现为夏季>春季>秋季>冬季,各季Margalef种类丰富度均值为3.54,Shannon-Weiner种类多样性均值为1.99,Pielou均匀度均值为0.71;各调查站位Margalef种类丰富度均值为7.87,Shannon-Weiner种类多样性均值为2.94,Pielou均匀度均值为0.75,表明该海域生物多样性处于较低水平。分析东山湾及其邻近海域游泳动物多样性,可为今后开展海洋工程建设渔业资源损益评价、生态环境修复工作和基于生态系统的渔业和海洋管理策略提供科学依据。     

黄海南部大型水母暴发区中小型浮游动物生态特征

根据2007年5-9月黄海南部(121°15'E-122°09'E、31°53'N-32°53'N)大型水母暴发区调查数据,对该区6个站点中小型浮游动物的种类组成、数量分布、群落特征及优势种等进行了分析.共鉴定出调查区浮游动物58种(不含鱼卵和仔鱼),隶属于5门11大类58种,其中桡足类为优势种,占80.86%;浮游动物总丰度均值为783.17 ind·m-3(452.23～1241.86 ind·m-3),最高密集区位于St.4;多样性指数(H')均值为2.76(2.44～2.95),调查区南部(St.4～St.6)比北部(St.1～St.3)的物种更为丰富;小拟哲水蚤(Para-calanus parvus)为最主要优势种,丰度为263.76 ind·m-3(152.23～451.89 ind·m-3),集中分布在St.4,浮游动物总丰度和总生物量大小取决于优势种小拟哲水蚤的丰度.线性回归分析揭示,浮游动物总生物量,总单位捕捞努力量渔获量(CPUE)正相关性显著,而水母CPUE-总CPUE、水母CPUE-小黄鱼CPUE均存在极显著的负相关关系.     

莱州湾金城海域浮游动物群落结构及与环境因子的关系

于2009年和2010年3—12月在莱州湾金城海域对浮游动物群落结构及其环境因子进行了连续20个月份的综合调查,共记录到浮游动物75种,分属14个不同大类。浮游动物以桡足类和浮游幼虫居多,分别鉴定出22种、20类,占种类总数的29.3%、26.7%,其次为水螅水母类,鉴定出11种,端足类、被囊动物、腹足类和栉水母类分别鉴定出6种、4种、4种、2种,其它枝角类、毛颚动物、等足类、糠虾类、磷虾类以及钵水母类各鉴定出1种。主要优势种为强壮箭虫(优势度Y=0.24)、中华哲水蚤(Y=0.13)、墨氏胸刺水蚤(Y=0.07)、以及洪氏纺锤水蚤(Y=0.02)。2009年与2010年浮游动物群落结构的变化趋势比较稳定,同一季节群落结构相似度达到40%以上。浮游动物丰度分别在2009年及2010年的5月份达到最高值951.65个/m3、1348.14个/m3。种类数分别在2009年9月和2010年6月达到最高值48种、40种。多样性指数分别在2009年10月及2010年5月达到最高值2.6、2.7,呈现明显的季节变化特征。典范对应分析(Canonical correspondence analysis,CCA)显示,水温和盐度是影响浮游动物群落结构最主要的影响因子,水温与浮游动物种类数的相关系数达到0.87(P0.01)。盐度与浮游动物数量的相关系数为0.484(P0.05)。透明度、化学耗氧量、pH、叶绿素及总氮总磷等环境参数对浮游动物群落结构的影响较弱。     

三沙湾浮游动物生态类群演替特征

根据2010年6月-2011年5月三沙湾海域5个航次海洋综合调查资料,对三沙湾浮游动物种群特征进行分析,并与我国不同纬度海湾生态类群结构进行比较.探讨三沙湾海域浮游动物生态类群季节变化特征及其受水团季节变化的影响.研究结果表明:4月和5月三沙湾海域主要受到浙闽沿岸流影响,生物多样性H'指数分别为2.03和2.02;种类数分别仅为17种和19种,明显低于6月、8月和10月;浮游动物生态类群以暖温带近海种为主;优势种种类数少,单一优势种优势性明显,4月中华哲水蚤丰度占浮游动物总丰度的65.03％;群落结构特征与同期我国长江口浮游动物区系特征相似.6月三沙湾海域受到浙闽沿岸流和台湾暖流共同影响,同时因闽北雨季导致大量大陆径流汇入,使得该月浮游动物种群结构复杂,生物多样性指数和种类数全年最高,为3.12和45种,与5月相比,种类更替明显,物种更替率为69.39％;亚热带近海种丰度百分比最高(73.03％),亚热带外海种种类数百分比次之(48.89％),是海域浮游动物生态类群由以暖温带近海种为主向以亚热带外海种为主的过渡时期.8月和10月浙闽沿岸流消失,三沙湾海域受台湾暖流控制,海水温度和盐度升高,生物多样性指数和种类数均略低于6月;生态类群结构以亚热带外海种为主;优势种特征表现为种类数多而各个优势种丰度较低;浮游动物群落结构特征与南海北部海域浮游动物组成极为相似.     

渔山列岛浮游动物的群落结构特征分析

2011年10月—2012年7月对渔山列岛浮游动物的种类组成、优势种、群落结构、丰度和生物量进行了调查,分析了浮游动物丰度、多样性指数及其与环境因子的相关性。调查共鉴定浮游动物8类45种,其中原生动物类14种,占31．1％;桡足类次之13种,占28．9％。主要优势种有中华哲水蚤（Calanussinicus）、根状拟铃虫（Tintin—nopsisradix）和桡足类幼虫（Copepoditenauplinua）。多样性指数（H＇）7月（3．324）最高,10月（2．988）最低。结合多样性指数及丰富度指数可见,调查期间渔山列岛浮游动物的生物多样性7月最高,物种较丰富。相关性分析表明,浮游动物群落分布与营养盐、水温、盐度等环境因子存在一定的相关性。     

湛江港湾浮游桡足类群落结构的季节变化和影响因素

2009年2月、5月、8月和11月分别对湛江港湾浮游动物进行了季度月调查,并对该海域浮游桡足类群落结构的季节变化及影响因素进行了分析.结果共鉴定出桡足类72种,其中冬季36种,占浮游动物种类数的29.5％;春季33种,占浮游动物种类数的39.3％;夏季24种,占浮游动物种类数的29.6％;秋季19种,占浮游动物种类数的40.4％.主要优势种为中华哲水蚤Calanus sinicus、强额拟哲水蚤Paracalanus crassirostris、短角长腹剑水蚤Oithona brevicornis、亚强真哲水蚤Eucalanus subcrassus、刺尾纺锤水蚤Acartia spinicauda和桡足类幼体.季节变化模式为:夏季丰度最高,达960.0个/m3,春季次之为421.0个/m3,冬季为303.4个/m3,秋季最低仅为252.8个/m3.平面分布冬春季丰度内湾高,往湾口逐渐降低,夏季内湾低往湾口逐渐增大,而秋季分布较均匀.调查海区桡足类丰度与水温、叶绿素a和浮游植物细胞丰度呈极显著的正相关,与DIN和PO3-4呈显著的负相关,与盐度、pH值和活性硅酸盐相关性不明显.     

珠江口横琴岛海域春季海洋浮游生物的初步研究

根据2008年5月在珠江口横琴岛海域的调查采样,本文对该海域的叶绿素a、初级生产力(C)、浮游动、植物进行了初步的研究,分析了浮游动、植物的种类组成、群落结构、数量和生物量等.结果表明,叶绿素a浓度和初级生产力(C)均值分别为5.27 mg·m^-3和123.56 mg·m^-2·d^-1.浮游植物共有111种,以硅藻为主,绝对优势种为中肋骨条藻Skeletonema costatum,调查海域浮游植物平均细胞丰度为6832.75×10⁴cell·m^-3,以近海广布种为主要类群,多样性指数和均匀度均值分别为2.29和0.45.浮游动物共有41种,暖水种沿岸类群种类占大多数,以中华异水蚤Acartiella sinensis为绝对优势种,平均丰度和生物量分别742.25 ind·m^-3和131.12 mg·m^-3,多样性指数和均匀度均值分别为2.54和0.67.     

Zooplankton Diversity of Osmansagar Reservoir,Telangana, India

Zooplankton composition and diversity in Osmansagar reservoir, Telangana, India were investigated during the year 2010–2012. Collected data revealed the occurrence of 66 species of zooplankton, of which 50 rotifers, 14 cladocerans and two copepods. The population density of zooplankton varied from 83 to 1080 Ind./L. The highest density was due to rotifer and copepod population. Diversity (H′) was ranged from 0.679 to 2.631, evenness (J′) was 0.257 to 0.904 and species richness was 8–24. The less diversity and evenness was observed in November 2011, March and August 2012, because of copepoda dominance by Mesocyclops leuckarti. The population abundance of zooplankton was Brachionus forficula, Brachionus diversicornis, Brachionus calyciflorus, Keratella tropica, Trichocerca similis and Diaphanosoma sp. especially during the summer seasons in both the years. There was no seasonal periodicity of any zooplankton communities, but the population turnover was observed from rotifers to copepoda over the study period. The significant inter and intra relationship between and within physicochemical and zooplankton indices were noted. It is found that surface water temperature, magnesium and total hardness could be a limiting factor for the species richness. Dominance may be due to the numerical abundance of rotifer and copepod and it has a positive significant correlation with pH.     

鸭绿江口近岸海域水质环境对冬季浮游动物群落结构的影响

定量分析滨海湿地近岸海域水质环境与浮游动物群落结构之间的关系对揭示海水水质环境健康状态具有重要意义。2019年12月在鸭绿江口湿地国家级自然保护区近岸海域开展了浮游动物和水环境因子调查,运用冗余分析和结构方程模型等方法探讨了水质环境对冬季浮游动物群落结构的影响。研究区共鉴定出浮游动物14种以及浮游幼虫5大类,桡足类最多占比52.63%;保护区不同功能分区间浮游动物群落结构总体差异不大,多样性指数、均匀度指数和丰富度指数平均值分别为1.34、0.51和0.59;浮游动物的种群分布与海水化学需氧量、溶解性无机氮、浮游植物群落多样性指数和铜元素含量关系显著;结构方程模型模拟结果表明,海水富营养化水平对浮游动物丰富度的效应系数为-0.26,具有显著的直接影响(P=0.01),重金属污染水平通过影响浮游植物丰富度(效应系数为-0.41,P<0.001)间接对浮游动物丰富度产生作用(间接效应系数为-0.2)。研究结果将有助于深化对海水环境和浮游动物群落结构协同演变过程的认识,为滨海湿地近岸海洋生态系统科学管理提供理论支撑。     

连作苹果园土壤真菌的T-RFLP分析

为探讨连作苹果园不同土壤空间真菌群落结构,应用T-RFLP(Terminal Restriction Fragment Length Polymorphism)技术,比较了3个连作园不同取样位置(行间、原穴、株间)和不同土层(0—30 cm、30—60 cm)的土壤真菌多样性,并结合不同样品TRFLP图谱的差异,采用多样性指数分析、聚类分析和主成分分析(PCA),分析了3个连作园土壤真菌群落结构特征。结果表明,磁窑、道朗和金城连作园的土壤真菌多样性存在差异,各采样地区的Shannon多样性指数在0.43—2.47之间,Pielou均匀度指数在0.17—0.85之间,Simpson优势度指数在0.12—0.81之间,Margalef丰富度指数最高的是金城树穴0—30 cm土层(R=4.55),最低的是磁窑行间30—60 cm土层(R=0.77)。在调查的不同取样位置、不同土层中,原树穴具有最高的多样性指数、均匀度指数、丰富度指数和最低的优势度指数;0—30 cm土层的土壤真菌多样性指数、均匀度指数、丰富度指数均高于30—60cm土层,而优势度指数的趋势正好相反;PCA和聚类分析结果显示磁窑、道朗和金城连作园的土壤真菌群落结构均有明显差异,3个连作园的土壤真菌各自构成一个独立的群落结构,这些群落能够适应各自的土壤环境并成为环境的优势群落。     

晋、陕、宁、蒙柠条锦鸡儿群落物种多样性对放牧干扰和气象因子的响应

根据晋、陕、宁、蒙地区13个样地的野外调查资料,采用丰富度指数、物种多样性指数以及均匀度指数,研究了柠条锦鸡儿群落物种多样性对放牧干扰和气象因子的响应。结果表明：（1）晋、陕、宁、蒙地区柠条锦鸡儿群落组成成分简单,共记录种子植物111种,分属25科,64属,灌木层优势种为柠条锦鸡儿,草本层优势种集中于禾本科、豆科、菊科蒿属和藜科;（2）受人为干扰、土壤和气候等影响,群落的组成、结构及其综合性质具有一定差异性,主要表现在群落的Patrick指数与Simpson指数、Shannon-wiener指数出现较大的波动,且波动趋势基本一致,Pielou指数表现较为稳定;（3）放牧干扰强度与群落Simpson指数、Shannon-wiener指数呈极显著相关（P＜0.01）,与Patrick指数、Pielou指数呈显著相关（P＜0.05）,群落丰富度随放牧干扰强度的增大而下降,群落多样性和均匀度指数在D2和D3时呈现峰值,表明适度干扰可以提高群落物种多样性和均匀度;（4）Patrick指数、Simpson指数和Shannon-wiener指数均与年均降水量呈极显著正相关(P＜0.01),与相对湿度呈显著正相关（P＜0.05）,共同体现了水分条件是制约柠条锦鸡儿群落物种多样性的决定性因子。     

A Comparative Study of the Far Eastern Seas and the Northern Pacific Ocean Based on Integral Parameters of Net Zooplankton in the Epipelagic Layer

Integral parameters of zooplankton community, including species diversity and its components were compared between the Chukchi Sea, Bering Sea, Sea of Okhotsk, Sea of Japan, and adjacent Pacific waters based on the data obtained by standard Juday net with a mouth area of 0.1 m² during the large-scale surveys conducted by the Pacific Fisheries Research Center (TINRO Center) in 1984–2013. These parameters were calculated for the total surveyed area of approximately 7.0 million km² and separately for each of the considered water bodies. In Pacific waters, species richness is higher than that in all the seas, while the concentration of individuals (expressed in terms of abundance, ind./m³) and evenness of their distribution over species were lower. The only sea with a larger mean size of organisms compared to the ocean is the Bering Sea. A lower species diversity than in the ocean has been recorded only from the Chukchi Sea; a lower density (in terms of biomass, g/m³) was determined only from the Sea of Japan. Among the four seas, the Chukchi Sea ranks first in terms of biomass and abundance of zooplankton, second in species evenness, third in the mean size of individuals, and last in species richness and diversity. The Bering Sea ranks first in terms of mean size of plankton organisms, second in species richness, diversity, and biomass, third in abundance, and last in species evenness. The Sea of Okhotsk ranks second in terms of mean size of individuals, last in their abundance, and third in the other parameters. The Sea of Japan ranks first in terms of species richness, evenness, and diversity, second in abundance, and last in mean size of zooplankton organisms, and, therefore, their biomass. The biomass of zooplankton, in accordance with the concentration of nutrients, increases in the southto-north direction (while its absolute abundance depends largely on the size of the body of water). The mean size of organisms increases in the same direction; the evenness of their distribution over species increases in the reverse direction (with the exception of both parameters for the Chukchi Sea). The rank of a water body for its biodiversity coincides with the species richness rank. The latter increases from north to south (except for the Okhotsk Sea), but greatly depends on the surveyed area and, even more, on the surveyed volume of water. A study of the literature data found some unexpected statistically significant relationships of the integral parameters of zooplankton with those of pelagic and bottom macrofauna, as well as with the parameters of zooplankton production, on the size of the considered bodies of water. The causes and the biological meanings of most of these relationships still do not have any rational interpretation. Their testing at other spatial scales will be continued in future works.     

Seasonal variation in abundance and diversity of zooplankton in Asu River,Ebonyi state,Nigeria

The Physicochemical variables and Zooplankton of Asu River, Ebonyi State, Nigeria were studied monthly between October 2013 and June 2014 which covered the wet and dry seasons. The study was carried out monthly in two selected sites by collecting water samples for physiochemical analysis and zooplankton identification. Shannon-Weiner diversity and Margalef's indices were used to determine the zooplankton composition. Investigation on the physiochemical variables showed that water temperature, dissolved oxygen, total dissolved solids, pH, conductivity and carbon (iv) oxide all recorded maximum values in the dry season. The present result also showed that the river is not seriously polluted. However, only carbon (iv) oxide and nitrate varied significantly between seasons (p < 0.05). Forty two (42) zooplankton species comprising Rotifera (7 families; 23 species), Copepoda (2 families; 8 species) and Cladoceran (6 families; 11 species) were identified. Rotifera spp. were numerically dominant and the most diverse group but the crustacean, Thermocyclops oithonoides dominated the total zooplankton biomass during the study. Species abundance showed inverse relationship with species richness, Shannon-Weiner diversity and Evenness. Zooplankton abundance was at its peak in the dry season while species richness, Shannon- Weiner diversity and evenness increased from dry season to wet season.     

Diversity measures in macroinvertebrate and zooplankton communities related to the trophic status of subtropical reservoirs: Contradictory or complementary responses?

Macroinvertebrate communities have been widely used as a tool for assessing the environmental quality of freshwater ecosystems, whereas zooplankton communities have been to some extent neglected. However, the importance of using different indicators to achieve a more comprehensive framework of assessment regarding water quality has been recognized. This study compared estimates of species richness (number of species) and the Shannon–Wiener index for data on macroinvertebrate and zooplankton communities in tropical reservoirs and related them to their trophic state. The trop+hic classification was obtained by applying the Carlson index (1977) modified by Toledo et al. (1983), and the index of the Brazilian Society of the Environmental Technology Agency. The comparative response of the different indicators was analyzed using a series of bivariate correlations (Draftsman’s plot). The results illustrate that diversity measures, namely species richness, responded differently when related to the trophic classification of reservoirs, depending on the community considered. The species richness of zooplankton was positively related to hypereutrophic conditions, due to the higher number of rotifer species, including tolerant generalist species and at the same time, as a result of the exclusion of species from other groups, whereas for macroinvertebrates, species richness was negatively related to hypereutrophic conditions. Melanoides tuberculatus, which exhibits a high tolerance and competitive ability under such conditions, was the dominant species in macroinvertebrate communities, which excluded endemic species and reduced local richness and diversity. The same indicators applied to the zooplankton and macroinvertebrate communities might therefore provide contradictory responses regarding ecological quality assessment in tropical reservoirs, which suggest that zooplankton should be taken into account among the biological quality elements considered in the ecological quality assessment, management, and restoration of water bodies.     

Analysis of the structure of bacteria communities and detection of resistance genes of quinolones from pharmaceutical wastewater

The aim of the present study was to investigate the distribution of bacteria and detect the presence of quinolone resistance gene (qnrA) and integrons (intI1, intI2) in a habitat polluted by pharmaceutical sewage. The bacteria were isolated by nutrient agar and nutrient broth from waste water and sludge collected from the sewage outfall of a pharmaceutical factory. The bacteria were identified by Gram staining and biochemical tests, and the bacterial community diversity was analyzed by Shannon–Wiener diversity index (H), Pielou evenness index (J) and Simpson’s diversity index (D). The occurrence of qnrA and integrons (intI1, intI2) were detected by Real-time PCR assays. The results showed that 90 strains were isolated from water samples and sludge samples including 22 genera and 26 species. Types of bacteria in water samples contained 18 genera and 20 species, while 13 genera and 14 species were detected in sludge samples. Fifty-five Enterobacteriaceae isolates (61.11 %, 55 of 90) were the predominant bacteria in water and sludge samples. Bacterial species richness and evenness in water samples were higher than in sludge samples. The resistance genes of qnrA and integrons (intI1, intI2) with the total DNA and single isolate plasmid DNA were detected. There were a variety of bacterial species and the presence of qnrA and integrons (intI1, intI2) genes in pharmaceutical wastewater habitats, in which Enterobacteriaceae strains were the dominant bacteria. These results suggested that pharmaceutical wastewater had potential risks to public health.     

Composition and community structure of pelagic copepods in the Indian sector of the Antarctic Ocean during the end of the austral summer

The present paper describes latitudinal and vertical changes in the composition, abundance and diversity of copepods in the Indian sector of the Antarctic Ocean, during the end of austral summer along a transect on 66°30′E between 43 and 62°S, within three layers (600–0, 200–0, 100–0 m). Highest copepod densities were noted in the central part of the transect, between the Antarctic Divergence and the Antarctic Convergence, with a maximum in the Antarctic Divergence zone, particularly in the upper levels of the water column. A total number of 80 copepod species were identified over the entire survey area. The south end and the central part of the transect comprised a small number of species. North of the Antarctic Convergence, this number increased markedly with the progressive disappearence of those species characteristic of Antarctic waters and their replacement by temperate and subtropical species. Generally, small copepods, particularly Oithona similis, Oithona frigida and Ctenocalanus citer, dominated in numbers in both Antarctic and sub-Antarctic areas. The contribution of large species to total copepod numbers was much lower, with Calanus simillimus in the central part of the transect, Pleuromamma borealis in the subtropical zone and Calanus propinquus in the southern part. Correspondence analysis showed a marked latitudinal gradient in population structure with four groups of samples and species corresponding to four latitudinal zones. Community structure (species richness, relative dominance index, evenness, Shannon species diversity index) and species abundance patterns (as rank-frequency diagrams) suggested that the maturity and species richness increased gradually from south to north. A low diversity index and evenness were observed in the area of the Antarctic Divergence, whereas the convergence zone showed high diversity and evenness. Conversely, the frontal zone showed high diversity and evenness. Distribution appeared unrelated to chlorophyll concentrations and on the large scale was related to the hydrologic characteristics. Received: 8 May 1996 / Accepted: 27 August 1996     

浙江大雷山夏蜡梅群落植物物种多样性及其与土壤因子相关性

分别采用物种丰富度、物种多样性指数和群落均匀度等指标对浙江省大雷山夏蜡梅群落植物物种多样性进行测定,并通过相关分析对各种指数与土壤因子的关系进行研究。据10个样地统计,共有维管植物74科、165属、193种。从种子植物属的地理成分来看,温带分布的类型居多。不同群落木本植物的物种丰富度和多样性指数以杉木+木荷林最高,群落均匀度以杉木林最高,毛竹林的各项指数最低。草本植物的物种丰富度以杉木+马尾松林最高,杉木林最低;多样性指数和群落均匀度以竹林最高,短柄枹+格药柃林最低。在不同群落的垂直结构中,乔木层的物种丰富度和多样性指数均小于灌木层,草本层的物种多样性在不同群落间变化较大。相关分析表明,夏蜡梅群落物种多样性与土壤有机质含量相关性较大,其中,木本植物物种多样性与有机质含量显著正相关,草本植物与有机质含量显著负相关。