香溪河水系大型底栖动物的群落结构及生态位

2005年7月～2006年6月对三峡水库湖北库区最大支流香溪河的大型底栖动物进行定量采集,并对所得数据进行了数理统计分析及生态位分析.结果表明,香溪河水系大型底栖动物物种丰富度在不同季节、不同支流间差异均显著;密度在各季节间差异显著.四节蜉、高翔蜉、锯形蜉、朝大蚊和扁蜉生态位较宽;Tetropina sp.、短尾石蝇、黑蝇生态位较窄.四节蜉、高翔蜉、锯形蜉、朝大蚊与其它分类单元生态位重叠值较大,黑蝇、短尾石蝇、直突摇蚊、Tetropina sp.与其它分类单元生态位重叠值较小.相对丰度和生态位宽度对生态位重叠值有重要影响.大型底栖动物主要通过在资源位上的分布、生态位重叠值大小,以及摄食类群和生活型等的差异缓解竞争.图2表5参25     

东寨港红树林区大型底栖动物多样性研究

于2010年3-12月对海南东寨港红树林区进行4次采样,研究该地大型底栖动物生物量、栖息密度的时空变化规律以及不同季节红树林群落大型底栖动物物种多样性的差异.结果表明,不同季节大型底栖动物的种类、数量差异极大,大型底栖动物种类以冬季为最多(45种),夏季为最少(28种),生物量以秋季为最高(272.78 g·m-2),夏季为最低(165.93 g·m-2),密度以冬季为最大(679.25 m-2),夏季为最小(504.95 m-2).对各站位大型底栖动物的生物量、栖息密度及不同红树群落底栖动物的物种多样性指数、丰富度指数和均匀度指数进行站位-季节间无重复的双因素方差分析,结果显示栖息密度、多样性指数和丰富度指数在季节间差异显著(P＜0.05),生物量、均匀度指数在站位间差异显著(P＜0.05).分析表明温度、盐度、底质和红树种类是导致大型底栖动物物种多样性存在差异的主要因素,东寨港红树林恢复有利于底栖动物生物量及物种多样性的增加.     

北京河流大型底栖动物空间格局及其环境响应研究

大型底栖动物群落结构及多样性对于区域河流环境状况具有重要的指示意义。基于2014年5月—2015年8月间北京市河流大型底栖动物群落结构调查数据,分析底栖动物的生物多样性特征和空间格局。调查共发现大型底栖动物151种(或分类单元),隶属于5门9纲67科127属,水生昆虫占绝对优势。聚类分析表明76个采样点可被分为4组,组1主要包含北部山区的潮白河水系,具有较为典型的山溪型河流底栖动物特征,组2主要包含永定河山峡段和北运河水系的清河,组3主要包含大清河水系和北运河水系的温榆河、北沙河、南沙河等,二者具有城市河流兼有山溪型河流底栖动物的特征,组4主要包含北运河水系,具有典型的城市河流底栖动物特征。优势种分析表明:组1的优势种为热水四节蜉(Baetis thermicus)、秀丽白虾(Exopalaemon modestus)和网栖石蛾(Cheumatopsyche sp.),组2为直突摇蚊(Orthocladius sp.)、钩虾(Gammarus sp.)和长足摇蚊(Tanypus sp.),组3为摇蚊科幼虫(larvae of Chironomidae)和寡毛类(Oligochaeta),组4是以中华摇蚊(Chironomus sinicus)为代表的摇蚊幼虫。功能摄食类群研究表明:组1以收集者和滤食者占绝对优势,相对丰度分别为60%和29.6%;组2、组3、组4均以收集者占绝对优势,相对丰度分别为97.7%、90%、97.5%。物种数、Shannon-Wiener多样性指数、Pielou均匀度指数和Margalef丰富度指数的组间差异性显著(P0.05)。研究表明,北京河流大型底栖动物受河流自然环境变化的影响显著,形成了典型的山区-城市底栖动物空间格局,山区河流中保持了较高的生物多样性,城市河流及其过渡区的大型底栖动物退化明显,大型底栖动物能够明显指示环境状况的变化并可指导河流环境的保护与恢复。     

贵州贞丰洞穴大型底栖动物群落结构及水质生物评价

了解洞穴大型底栖动物的群落结构是研究洞穴生态系统的重要内容,也是对生态学领域研究的重要补充.于2019年10月（平水期）及2020年8月（丰水期）对贵州省贞丰县5个洞穴内大型底栖动物进行采样调查,分析大型底栖动物组成、优势种、多样性、功能摄食群的分布特征,并基于大型底栖动物生物学指数对洞穴水质进行评价.结果得出：两个水期共获大型底栖动物63种,隶属4门7纲19目46科,其中水生昆虫41种,占65.07%,闪蚬Corbicula nitens、四节蜉Baetis sp.、蚋Simulium sp.是两个水期的共有优势种.在时间上,大型底栖动物的密度、生物量和多样性指数（ShannonWiener、Pielou和Margalef指数）均表现为平水期>丰水期.在空间上,密度和Margalef指数表现为有光带>弱光带>黑暗带,生物量、Shannon-Wiener指数和Pielou指数表现为弱光带>有光带>黑暗带. Jaccard相似性系数和聚类分析结果表明,同一洞穴相邻光带之间的相似性较高,不同洞穴相同光带或不同光带之间的相似性偏低.洞穴大型底栖动物由5个功能摄食...     

椒江口海域大型底栖动物数量与多样性的分布特征

入海河口受到海水、淡水以及人类活动的共同影响,生境复杂,其区域的底栖动物群落结构的变化能表征入海河口的环境变化以及人类活动的强度.对2010年4月(春季)、7月(夏季)和10月(秋季)椒江口海域大型底栖动物数量与多样性的分布特征开展研究,并分别用多样性指数法和丰度/生物量曲线比较法(ABC曲线)探讨底栖动物群落受污染扰动的程度.结果显示:椒江口海域3个季节共采集大型底栖动物60种,其中多毛类和软体动物是该海域的主要类群.季节分布上,春季种类数、丰度、生物量以及各项多样性指数均明显低于夏季和秋季.最高丰度(187.11个/m2)和最高生物量(69.82 g/m2)分别出现在夏季和秋季.空间分布上,底栖动物种类数、丰度、多样性指数和丰富度指数各季均呈现近岸站位明显低于大陈岛附近站位的现象;夏季和秋季,生物量在S7和S8号站附近形成一个明显的高值区,其中S8在秋季生物量达到913.63 g/m2;均匀度指数则分布较均匀.本研究表明,椒江口海域大型底栖动物数量与多样性的分布特征与多毛类的分布特点密切相关,多样性指数法和ABC曲线法对群落受污染扰动程度的评价结果截然相反.     

神农架林区河流生态系统健康评价

为监测神农架林区河流健康状况及人为活动对其水体理化特征和生物群落的影响,基于水质类别、大型底栖动物Shannon-Wiener多样性指数及BMWP记分系统(Biological Monitoring Working Party Score System)对神农架林区河流生态系统健康进行评价.结果显示,水质、大型底栖动物Shannon-Wiener多样性指数以及BMWP记分系统评价为健康的样点比例分别为36.67%、63.30%和50%.大型底栖动物Shannon-Wiener多样性指数和BMWP记分系统2种评价方法的结果存在极显著的相关性(P0.01),具有较好的一致性.3种评价方法均显示亚健康或健康状态的样点比例达到了66.67%,表明神农架林区河流生态系统总体健康状况良好,但部分样点受到了一定程度的污染与干扰.     

江苏省不同营养状况湖泊底栖动物群落结构与多样性比较

为了解江苏省湖泊底栖动物群落结构和多样性并研究其对水环境质量变化的响应,于2012年春秋两季对江苏省16个湖泊51个采样点湖泊底栖动物群落结构与多样性以及湖泊综合营养状态指数进行调查,分析水质指标与底栖动物指数间Pearson相关关系。结果表明,江苏省16个湖泊营养状态指数范围为35.5~66.4,其中约81.2%的湖泊处于轻度-中度富营养状态,表明水质从好到中度污染;湖泊底栖动物优势种为寡毛类的霍甫水丝蚓(Limnodrilus hoffmeisteri),优势度为13.0%;香浓多样性指数(Shannon-Wiener diversity index)范围为0.00~2.20,级别范围由极贫乏到较丰富状态,表明水质污染程度从重度到轻度污染。从全省尺度看,水质评价结果与生物学(香浓多样性指数、Pielou均匀度指数和Biotic Index(BI)指数)评价结果存在一定差异。与历史数据相比,江苏省湖泊底栖动物清洁敏感物种减少甚至消失,总体群落结构趋于小型化。16个湖泊水体总氮和总磷与底栖动物密度呈显著负相关,而综合营养状态指数与底栖动物指数(香浓多样性指数、Pielou均匀度指数和BI指数)间关系不显著。上述研究结果表明综合营养状态指数无法完全客观反映湖泊水生态健康状况,因此需要综合水质、水文、水生生物、生境状况等因素发展新的评价指标体系。     

月湖底泥疏浚后底栖动物群落的恢复及其与环境的关系

研究对月湖底泥疏浚后底栖动物群落动态进行逐月的周年调查,并分析了底栖动物密度、生物多样性与环境因子的关系,结果表明：疏浚导致大型底栖动物基本消失,现存量从疏浚前的（4387±885）ind·m-2降低至（80±21）ind·m-2。疏浚后,寡毛类成为受干扰系统恢复过程中的先锋种类,在春季（4月）和秋冬之际（11月）出现2个密度高峰,分别为（1010±230）ind·m-2和（1538±408）ind·m-2,而摇蚊幼虫在疏浚一年后的秋冬季密度达到高峰（2021±612）ind·m-2,二者均基本恢复到疏浚前的密度水平。种类组成与疏浚前相似,优势种类数较疏浚前多,7月份以前,以霍甫水丝蚓占绝对优势,7月份以后以长足摇蚊占绝对优势。生物多样性在秋冬季恢复到疏浚前水平。寡毛类、摇蚊幼虫的密度、生物多样性与湖水溶氧、透明度呈显著正相关,与水体营养水平（TN、TP、有机碎屑）呈显著负相关（P〈0.05）。分析认为疏浚后底栖动物群落的季节变化与动物的生命周期（繁殖和生长）密切相关,而营养水平不是限制动物种群密度分布的主要因子。从底栖动物群落的恢复情况来看,疏浚后的底质环境更有利于底栖动物群落的生存和底栖生态系统的重建。     

湖北省湖泊大型底栖动物群落结构及水质生物学评价

大型底栖动物是湖泊生态系统的重要生物类群,在生态系统物质循环和能量流动中起着重要作用。底栖动物具有生命周期长、迁移能力较弱、对环境变化反应敏感等特点,可有效指示湖泊生态系统的健康状况。湖北省是我国淡水湖泊分布最密集的区域之一,湖泊总面积为3025 km2。近年来,伴随着工农业、养殖业及城市化的快速发展,富营养化已成为本地区湖泊面临的一个主要环境问题,并可能直接影响大型底栖动物的群落结构。目前关于本地区湖泊大型底栖动物群落的研究还较少,为此本研究对湖北省27个浅水湖泊底栖动物进行了调查,并对水质状况进行生物学评价。共采集到底栖动物40种,隶属于4门7纲18科,其中寡毛类5种,摇蚊幼虫16种,软体动物双壳类4种、腹足类8种。霍甫水丝蚓（Limnodrilus hoffmeisteri）、苏氏尾鳃蚓（Branchiura sowerbyi）、花翅前突摇蚊（Procladius choreus）、中国长足摇蚊（Tanypus chinensis）、多巴小摇蚊（Microchironomus tabarui）及铜锈环棱螺（Bellamya aeruginosa）是本地区湖泊最常见的种类。所调查湖泊底栖动物平均密度为32~1243 ind·m-2,其中12个湖泊密度低于200 ind·m-2,摇蚊幼虫和寡毛类对密度的贡献较大,以摇蚊幼虫占优势的湖泊有19个。底栖动物平均生物量为0.034~460.7 g·m-2,生物量低于50 g·m-2的湖泊数量最多（19个）,软体动物占优势的湖泊有16个,摇蚊幼虫和寡毛类占优势的湖泊数量共11个。各湖泊底栖动物物种数为3~14种,Margalef指数为0.71~2.33,Simpson指数为0.69~0.85,Shannon-Wiener为0.78~2.13,Spearman相关性分析结果显示物种丰富度和三种多样性指数与湖泊面积呈显著正相关。BI（Hilsenhoff生物指数）评价结果显示共11个湖泊为一般和轻度污染（6.01~7.44）,中度污染湖泊数量为13个（7.57~8.47）,长湖（8.52）、上津湖（8.65）和玉湖（8.50）处于重污染状态。     

网围养殖对滆湖底栖动物群落组成及物种多样性的影响

2002年4月、7月、11月和2003年1月对滆湖底栖动物群落组成、分布及多样性现状进行了研究.结果表明,滆湖现有底栖动物31种,其中软体动物14种,淡水寡毛类6种,水生昆虫7种和水蛭4种.主要优势种为梨形环棱螺和羽摇蚊.相似性分析表明,滆湖网围养鱼区和网围养蟹区底栖动物群落组成相似程度较高,而都与非养殖区差异较大,说明网围养殖对底栖动物组成存在影响;而且网围养鱼对底栖动物的影响更甚于网围养蟹的影响.多样性分析表明,滆湖底栖动物多样性呈现自北向南递增以及夏秋低、冬春高的时空变化格局.图3表2参17     

Microhabitat association in white-streaked grouper Epinephelus ongus: importance of Acropora spp.

Microhabitat associations are considered to be important for juvenile survivorship and growth of coral reef fishes. The aim of the study was to quantify microhabitat associations between juvenile and adult white-streaked grouper Epinephelus ongus, which supports important fisheries in coral reef areas. Underwater observations revealed that most juveniles were found in bottlebrush Acropora spp., staghorn Acropora spp. and coral rubble and there was a significant positive use of bottlebrush Acropora spp. and a significant negative use of coral rubble. For adults, most individuals were found in bottlebrush Acropora spp. and staghorn Acropora spp., and there was a significant positive use of staghorn Acropora spp. and significant negative use of coral rubble. A habitat choice experiment by using pre-settlement individuals revealed that both bottlebrush Acropora spp. and staghorn Acropora spp. were used as settlement sites, whereas coral rubble was rarely used as a settlement site. Results of the study suggest that juvenile and adult E. ongus showed significantly positive microhabitat associations with bottlebrush Acropora spp. and staghorn Acropora spp., respectively, in the field. Bottlebrush Acropora spp. has smaller inter-branch spaces than staghorn Acropora spp., which could drive patterns of microhabitat associations. In addition, post-settlement processes such as predation may influence the spatial distribution of juveniles. Because Acropora corals are very susceptible to coral bleaching, we predict that rising temperatures from climate change will negatively impact populations of E. ongus.     

Biodegradation of 2-methylisoborneol by bacteria enriched from biological activated carbon

One of the most common taste and odour compounds (TOCs) in drinking water is 2-methylisoborneol (2-MIB) which cannot be readily removed by conventional water treatments. Four bacterial strains for degrading 2-MIB were isolated from the surface of a biological activated carbon filter, and were characterized as Micrococcus spp., Flavobacterium spp., Brevibacterium spp. and Pseudomonas spp. based on 16S rRNA analysis. The removal efficiencies of 2-MIB with initial concentrations of 515 ng·L^-1 were 98.4%, 96.3%, 95.0%, and 92.8% for Micrococcus spp., Flavobacterium spp., Brevibacterium spp. and Pseudomonas spp., respectively. These removal efficiencies were slightly higher than those with initial concentration at 4.2 mg·L^-1 (86.1%, 84.4%, 86.7% and 86.0%, respectively). The kinetic model showed that biodegradation of 2-MIB at an initial dose of 4.2 mg·L^-1 was a pseudo-first-order reaction, with rate constants of 0.287, 0.277, 0.281, and 0.294 d^-1, respectively. These degraders decomposed 2-MIB to form 2-methylenebornane and 2-methyl-2-bornane as the products.     

Application of sensory and microbial analysis to assess quality of fish in Siliguri city of West Bengal, India

Sensory and certain microbial analyses were applied to assess the quality of raw fish sold at a market in Siliguri cityof West Bengal, India. In regular surveys undertaken during June to August 2008, a particular fish species was randomly selected, its source was noted and a sensory analysis, the quality index method (QIM) was applied to assess its quality Raw fish samples were also collected and a small quantity (about 1 g) of scales oran upper layer of the skin surface (forscale-less fish samples), gill, liverand a portion of gut with gut-contents were aseptically removed for enumeration of the total aerobic heterotrophic bacteria, Aeromonas spp., Pseudomonas spp., Salmonella spp. and coliform counts. Oreochromis mossambicus and Tenulosa ilisha recorded significantly higher QIM scores, compared to other species (p<0.05). Riverine fish, Lepidocephalichthys guntea and Channa punctatus scored the lowest QIM scores (0) while scores for Puntius ticto and Mystus vittatus and pond cultured species like Cirrhinus mrigala, Catla catla, Labeo rohita, Labeo bata and Cyprinus carpio were very marginal (p<0.05). Aeromonas spp., Salmonella spp. and total coliforms were recorded from all the studied species while Pseudomonas spp. was isolated from only seven species. Among the tissues examined, the lowest counts of total heterotrophic bacteria, Aeromonas spp., Pseudomonas spp., Salmonella spp. and total coliforms were recorded from the skin in every fish species. Highest counts of pathogenic bacteria (except Pseudomonas spp.) were recorded in Tenulosa ilisha for all the tissues except liver. Since fish are properly cooked in Bengali households, the risk of disease from fish consumption is relatively less. However, some tribes residing in the region are known to consume undercooked fish and proper cooking methods should be followed in view of the present findings to avoid health risks. Besides, utmost care should be taken while handling fish.     

木麻黄根区土壤理化特性及酶活性与青枯病发生关联分析

为探究木麻黄(Casuarina spp.)根区土壤理化特性及酶活性与青枯病发生的关系,进而为加强生物防治提供参考.选取位于广东省潮州市饶平县大埕镇、湛江市吴川市塘尾镇和湛江市徐闻县前山镇的3个木麻黄人工林为研究对象,在每个林分下分别设置3个样地,每个样地采集木麻黄青枯病感病植株和健康植株根区土壤各3份,共54个土壤样...     

Seasonal variation of membrane fluidity of the naturally acclimatized Baltic Sea amphipods Gammarus spp. and Monoporeia affinis

The membrane fluidity of the Baltic Sea crustaceans Gammarus spp. and Monoporeia affinis was studied in different seasons. Gammarus spp. were collected at a location with stable salinity and with temperature fluctuations from about 0 to 20 °C, and M. affinis at a deep location with stable salinity and a constant low temperature of about 1.5 to 4.5 °C. The membrane fluidity was measured from preparations enriched with plasma and mitochondrial membranes employing a fluorescence polarization technique using 1,6-diphenyl-1,3,5-hexatriene (DPH) as a probe. The measurements were carried out without any preceding acclimation of the animals. In Gammarus spp., the membrane fluidity increased in the order: summer animals < autumn animals < spring animals. The differences between seasons were significant, with pronounced homeoviscous adaptation, and correlated well with the water temperature. It is suggested that in Gammarus spp., temperature is the determining factor for membrane fluidity. In M. affinis, the membranes of summer animals were the most fluid, and there was a significant difference only between summer and spring animals. In M. affinis the difference was not connected to the water temperature and no homeoviscous adaptation was noticed. The deep-water M. affinis experience a long period of fresh food deficiency, which probably affects the membrane fluidity. Although there are seasonal differences in fluidities between Gammarus spp. and M. affinis, it is interesting to note that all data obtained from M. affinis settled between the polarization lines of spring and summer Gammarus spp., regardless of the prevailing temperatures. Received: 30 June 1999 / Accepted: 7 June 2000     

低效低质人工林优化改造后林下植被多样性研究

采用样地调查法,对经过人工优化改造的陕西吴起县城周边的低效低质林,选取了其中的11种改造模式（即人工林林分）及1块天然次生林,进行了林下植被多样性的研究。结果表明：12个样地共调查到55种植物,各样地林下植物种有11-23种;阿尔泰狗娃花（altaicus（Willd．）Novopokr．）、达呼里胡枝子（davuriea（Laxm．JSehi月d1．）、赖草（JPc口li”淞（GeorgOTzveL）、针茅（capillataLinn．）、毛连蒿（vestitaWall．exBess．）和委陵菜（chinensisSer．）是最常见的种。而赖草、毛连蒿、达呼里胡枝子、华北米蒿（giraldiiPamp．）、茵陈蒿（capillarisThunb．）、艾蒿（1avandulaefolia DC．）是改造后人工林林下重要值最大的优势种,植物偶见种也较多;不同样地林下植物多样性指数差异显著;物种多样性指数Gleason指数和种间相遇机率（PIE）指数变化趋势基本一致,Simpsom指数、Pielou均匀度指数变化趋势与前两者相反,Shannon—Wiener指数变化趋势不明显。分析表明：人工林林下植被多样性较之天然林要差,其多样性受人工林林分密度、林龄及林分组成等影响。     

Feeding habits of the dungeness crab Cancer magister as determined by the index of relative importance

Specimens of the Dungeness crab Cancer magister, were collected subtidally and intertidally from an estuary in Washington State, USA in June and September 1980, and January, April, May and July, 1981. Gut contens of freshly collected crabs were analyzed by the Index of Relative Importance; for each prey taxon, this method measured frequency of occurrence, percentage of total biomass, and percentage of total numbers consumed. The most important higher taxon eaten was fish; however, the most important prey genus was the shrimp Crangon spp. There was greater predation on Crangon spp. at night at the intertidal site, and during winter and spring when the shrimp were most abundant there. Feeding activity, as indicated by a weight-specific gut-fullness index, showed no consistent diel pattern. There were significant ontogenetic changes in feeding patterns: first-year crabs preyed primarily on very small bivalves or small crustaceans including their conspecifics; second-year crabs preferred Crangon spp. and fish, and third-year crabs preyed less on Crangon spp. and more on fish. Such changes in feeding habits with ege could be purely due to mechanics of food handling, but might also reduce competition among age groups of crabs, possibly partitioning resources within the estuary. Findings are discussed in terms of optimal foraging and compared to other similar studies.Contribution No. 599, School of Fisheries, University of Washington, Seattle, Washington 98195, USA     

Cellular damage of plant pathogenic fungi by antifungal compounds produced by Bacillus spp. isolates

The use of microorganisms as biological control agents (BCAs) has become an effective alternative to chemical means of controlling plant pathogens. The antagonistic and inhibitory activity of 71 Bacillus spp. strains, which were isolated from different Mexican sites, were tested against several phytopathogen fungi, Fusarium oxysporum, Fusarium equiseti, Fusarium avenaceum, Bipolaris spp. and Alternaria spp. From the antagonism study, the strain ELI149 showed a marked inhibition of growth against all tested fungi; therefore crude metabolites from this strain were extracted using ethyl acetate and amberlite resin and probed against the same fungi as well as strains of Mucor sp., Penicillium spp. and Paecilomyces spp. The results indicated that amberlite was more suitable for extraction of secondary metabolites with antifungal activity. Finally, observation of cell damage in the tested pathogenic fungi showed marked morphological changes on reproductive structures in all tested fungi indicating that antibiosis was the mechanism of the antagonistic effect. These results suggest that metabolites from the Bacillus strains have a wide spectrum of antibiotic activities, which can be used as biocontrol agents for controlling fungal plant diseases of agricultural importance.     

四川省部分豆科植物根瘤菌的遗传多样性

从四川省豆科植物鸡眼草属、合欢属、豇豆属、葛属、金合欢、杭子梢分离获得了103株根瘤菌,采用AFLP、BOXAIR-PCR研究了这些菌株的遗传多样性.结果表明,分离自四川省豆科植物6个属的根瘤菌存在明显的遗传多样性,AFLP分析中,全部供试菌株的相似性为21%,全部供试菌株可分为26个AFLP遗传群;BOXAIR-PCR聚类分析结果表明,103个菌株分在70%相似性水平处,供试菌株被分为18个BOX遗传群.除部分菌株外,多数根瘤菌按宿主类型聚群,同一宿主而地理来源不同的根瘤菌分布于不同的遗传群,表明宿主和地理环境对根瘤菌具有深刻影响.图3表1参9