广东肇庆星湖浮游甲壳类的生态调查

1996年4月至1997年8月对广东肇庆星湖的两个重要子湖(里湖和中心湖)的浮游甲壳类进行6次调查.共观察到枝角类17种,桡足类11种.两个湖泊浮游甲壳类的种类组成差异不显著,但数量及生物量差异十分显著,这与两湖泊的水质不同特征有密切关系.     

广东肇庆星湖浮游甲壳类的生态调查

1996年4月至1997年8月对广东肇庆星湖的两个重要子湖（里湖和中心湖）的浮游甲壳类进行6次调查,共观察到枝角类17种,桡足类11种。两个湖泊浮游甲壳类的种类组成差异不显著,但数量及生物量差异十分显著,这与两湖泊的水质不同特征有密切关系。     

镜检脑脊液白细胞定量计数方法改进的研究

目的:建立手工法镜检脑脊液白细胞定量的快速、准确、直观的检测方法,并验证该方法比传统方法准确并可靠性高。方法:无菌条件下采集患者脑脊液标本230例,分别采用中华人民共和国卫生部医政司出版的《全国临床检验操作规程》上的规程法、定量法。两种方法对于同一样本进行白细胞数计数,实验重复3次,用单因素方差分析进行统计学比较。结果:镜检脑脊液白细胞计数定量的方法比传统的方法(P>0.05,sd,cv值更小)更准确精密可靠。结论:计数定量的方法比规程法更准确,精密,可靠。     

田间麦蚜计数方法的研究

<正> 麦蚜是小麦等作物上的一类重要害虫,常发生年份会造成小麦5～10％的产量损失。关于它的防治指标,生产上一般以百株(穗)或单株(穗〕有多少头而确定的。然而,逐株(穗)计数(简称逐个计数法)蚜虫,不但费时,而且不可避免地带来较大的偏差。所以,目前在生产上又采用了麦蚜指数调查法和以蚜虫单位计数蚜虫的方法。然而,这二种方法与逐个计数法之间有什么关系,怎样将这后二种方法运用到麦蚜的防治指标上去,目前很少有人研究。为此,     

湖泊生态系统健康定量评价方法

提出了湖泊生态系统健康定量评价的一种新方法生态系统健康指数法。该方法首先设计了一个0～100的生态系统健康指数作为定量尺度,然后通过评价指标选择、各指标生态系统健康分指数计算、各指标权重计算、生态系统健康综合指数计算等基本步骤,评价湖泊生态系统健康状态。以实用实例对意大利西西里湖泊群及单个湖泊进行了生态系统健康评价。结果表明,该方法原理简单,计算简便,结果可靠、直观,既可用于同一湖泊又可用于不同湖泊生态系统健康状态的定量评价与比较,是一种值得推广的定量评价方法。     

一种简易的植物原生质体计数方法

植物原生质体培养和植物细胞悬浮培养是作物遗传改良、次生代谢物生产以及生物学基础研究中的常用技术。统计原生质体培养中的培养密度 (一般每ｍｌ培养液中应达到 10 4 ～ 10 6 个细胞 )和活力对实验的成功与否是很重要的[1] 。由于植物原生质体 ,尤其是由愈伤组织而来的原生质体直径比较大 ,用常规的血球计数板统计原生质体数存在一定的问题。如现在实验室一般采用的血球计数板为上海医用光学仪器厂的产品 ,其槽的深度为 0 .1ｍｍ ,“井”字形中央区的 2 5个大格中的液体体积只有 0 .1μｌ(0 .1ｍｍ× 1ｍｍ× 1ｍｍ) ,而要求其中的细胞数…     

定量蛋白质组学无标记定量方法的研究进展

依靠质谱技术的蛋白质组学快速发展,寻求速度快、重复性好以及准确度高的定量方法是该领域的一项艰巨任务,定量蛋白质组学分支领域应运而生．其中,无标记定量方法以其样品制备简单、耗材费用低廉以及结果数据分析便捷等优点渐露锋芒．无标记定量方法通常分为信号强度法和谱图计数法两大类．本文在这两种无标记定量方法计算原理的基础上,针对各种常用的无标记定量方法及最新进展做一个较为全面的介绍,并将详细讨论两类方法的异同点,以及目前蛋白质组学中无标记定量方法所面临的主要挑战,希望能为这一领域的研究人员在选择无标记定量方法时提供一个合理的参考．     

河南南湾水库浮游硅藻的种群结构与水质污染评价初步研究

通过对南湾水库6个采样点浮游硅藻分析,该水库硅藻61个种及种下分类单元。用多样性指数(H′)、均匀性指数(E)及硅藻优势种生态谱分析,对水质进行了初步评价。结果表明,南湾水库水质属清洁-轻污染等级。     

地下水生态系统健康评价指标体系的构建

地下水生态系统是重要的生态系统类型,由于地下水资源不合理的开发利用和污染物排放强度的增大、并长期积累,已导致许多地方产生生态环境劣变,甚至酿成难以弥补的严重后果,地下水生态系统健康问题已经成为许多国家和地区重点关注的环境问题之一.在科学把握地下水生态系统健康的概念和内涵的基础上,从系统结构特征、生态功能、资源功能、系统保护以及社会环境等5个方面选取了29个典型指标构建了地下水生态系统健康指标体系,对关键评价指标的意义进行了具体分析.出于服务于地下水生态系统健康评价的目的,对重要指标的评价标准进行了划分,并探讨了地下水生态系统健康评价的主要方法及发展方向,研究成果在一定程度上可以丰富生态系统健康评价研究理论与方法体系.     

Some studies on the ecology of limnetic crustacean zooplankton in Lake Begnas and Rupa,Pokhara Valley,Nepal

Monthly zooplankton samples taken during the period February, 1977 to February, 1978 in the deepest portion in two shallow sub-tropical Lakes, Begnas and Rupa in the Pokhara Valley, Nepal were studied. Four peaks of zooplankton abundance were noted. Adult and copepodid Copepoda were numerically dominant in both lakes with 56% Copepoda, 24% Cladocera and 20% nauplii in Lake Begnas and 48% Copepoda, 36% Cladocera and 16% nauplii in Lake Rupa. Other forms like Chaoborus larvae occurred sporadically in both lakes. An occurrence of the rare Limnocnida nepalensis (Coelenterata: Limnomedusae) in Lake Rupa was also noted during April and May, 1977. Although both of these lakes had already been ranked as eutrophic, the absence of calanoids, relative abundance of Bosmina longirostris and higher gross primary production in Lake Rupa is an indication of a higher trophic condition than that of Lake Begnas.     

Feeding and egestion rates of individual zooplankton using Cerenkov counting

Cerenkov radiation was used to measure ingestion and release by Brachionus calyciflorus and Daphnia pulex that were fed ³²P-labeled Rhodotorula glutinus. A method is described that uses automatic pipet tips as cages, permitting measurement of ingestion rates and isotope loss by individual animals. Estimated gut renewal times were 16 min for B. calyciflorus and 25–28 min for D. pulex. Filtering and ingestion rates for both animals agree closely with previous estimates. B. calyciflorus release ³²P at high rates in several pulses of short duration. Loss of ³²P by D. pulex occurs at a slower rate and in a single pulse sustained over a longer period. 32P release by B. calyciflorus was not dependent on the presence of food, whereas food influenced the timing and quantity of ³²P release by D. pulex.Financial support to JFH was provided by the Alexander von Humboldt-Stiftung.Financial support to JFH was provided by the Alexander von Humboldt-Stiftung.     

巢湖微囊藻和浮游甲壳动物昼夜垂直迁移的初步研究

2002年10月进行了巢湖微囊藻和几种优势浮游甲壳动物的昼夜垂直变化的研究,结果表明:微囊藻具有明显的昼夜垂直变化现象。白天上层水中的微囊藻密度显著高于下层水中,夜晚逐渐下沉使得下层水中的密度相对高于上层水。微囊藻与叶绿素a、水温、溶解氧和pH等均呈显著的正相关(p<0.01)。几种优势浮游甲壳动物的昼夜垂直迁移存在较大的差异。短尾秀体溞和角突网纹溞白天在下层水(1.5m和2.5m)中的密度较高,夜晚则倾向于在上层水(0m和0.5m)中活动。相反,卵形盘肠溞白天在上层水中密度较高,象鼻溞则在11:00和15:00时各水层中的密度显著高于夜晚。汤匙华哲水蚤和广布中剑水蚤白天倾向于在下层水中活动,夜晚则逐渐迁移到上层水中。许水蚤在夜晚和凌晨3:00时各水层中的密度显著高于白天。中华窄腹剑水蚤昼夜垂直变化不明显。微囊藻与短尾秀体溞密度呈显著的负相关,而与象鼻溞和卵形盘肠溞呈显著的正相关(p<0.01)。     

Field and experimental studies on the combined impacts of cyanobacterial blooms and small algae on crustacean zooplankton in a large,eutrophic, subtropical,Chinese lake

Field and experimental studies were conducted to evaluate the combined impacts of cyanobacterial blooms and small algae on seasonal and long-term changes in the abundance and community structure of crustacean zooplankton in a large, eutrophic, Chinese lake, Lake Chaohu. Seasonal changes of the crustacean zooplankton from 22 sampling stations were investigated during September 2002 and August 2003, and 23 species belonging to 20 genera were recorded. Daphnia spp. dominated in spring but disappeared in mid-summer, while Bosmina coregoni and Ceriodaphnia cornuta dominated in summer and autumn. Both maximum cladoceran density (310 ind. l⁻¹) and biomass (5.2 mg l⁻¹) appeared in autumn. Limnoithona sinensis, Sinocalanus dorrii and Schmackeria inopinus were the main species of copepods. Microcystis spp. were the dominant phytoplankton species and formed dense blooms in the warm seasons. In the laboratory, inhibitory effects of small colonial Microcystis on growth and reproduction of Daphnia carinata were more remarkable than those of large ones, and population size of D. carinata was negatively correlated with density of fresh large colonial Microcystis within a density range of 0–100 mg l⁻¹ (r = −0.82, P< 0.05). Both field and experimental results suggested that seasonal and long-term changes in the community structure of crustacean zooplankton in the lake were shaped by cyanobacterial blooms and biomass of the small algae, respectively, i.e., colonial and filamentous cyanobacteria contributed to the summer replacement of dominant crustacean zooplankton from large Daphnia spp. to small B. coregoni and C. cornuta, while increased small algae might be responsible for the increased abundance of crustacean zooplankton during the past decades.     

Crustacean zooplankton community structure in temporary and permanent grassland ponds

Lentic community structure varies across a size gradient of ponds and lakes with physical factors, such as pond drying, and biotic factors, such as fish predation, determining the species assemblage. We studied the effects of pond drying and fish absence on crustacean zooplankton across a gradient of pond sizes in a Texas grassland. We determined the species compositions and size distributions of crustacean zooplankton in 20 temporary and 18 permanent ponds in April after March rains had refilled the ponds. The surface areas of temporary and permanent ponds ranged from <0.01 to 0.21 ha and 0.04 to 13.8 ha, respectively, and temporary ponds were significantly smaller, on average, than permanent ponds. Fish were absent from all temporary ponds and present in all permanent ponds. We detected a difference in the zooplankton species assemblages of the temporary and permanent ponds. Out of 14 total zooplankton taxa that occurred in eight or more ponds, seven taxa were significantly more prevalent in temporary ponds and four taxa were significantly more prevalent in permanent ponds. The sizes of zooplankton in the temporary fishless ponds were greater than those in the permanent ponds with fish present. We concluded that pond size mediated susceptibility to pond drying, and pond drying determined the presence and absence of fish and their secondary trophic-level effect on zooplankton community structure. Handling editor: Steven Declerck     

The effects of CO2 on sestonic stoichiometry and community structure of crustacean zooplankton in a eutrophic lake: Increased competitive ability of Bosmina

To explore the effects of CO₂ concentration on the sestonic stoichiometric values and the community structure of crustacean zooplankton in a eutrophic lake, in situ microcosm experiments were conducted at the Lake Taihu Ecosystem Station in spring and summer of 2012. The experimental treatments were three concentrations of CO₂, 270, 380 and 750 ppm, which represented preindustrial and present levels and the level predicted for the end of this century, respectively. The elevated atmospheric CO₂ concentration increased the sestonic C:P ratio, particularly in the spring when the C:P ratio was two-fold greater at the high level of CO₂ than at the low level of CO₂. As a result, the contribution of Bosmina to total crustacean zooplankton abundance increased, most likely because of the low phosphorus content and high adaptability to foods with large elemental ratio variation. The other dominant crustacean zooplankton genera, including Daphnia, Ceriodaphnia, Diaphanosoma and Sinocalanus, had no response to the change in pCO₂ during the microcosm experiments. The shift in crustacean zooplankton community structure between two seasons was primarily due to the transition of the phytoplankton community.     

Comparison of methods used in zooplankton sampling and counting in the joint Russian-Finnish evaluation of the trophic state of Lake Ladoga

The results of a joint Russian-Finnish investigation on zooplankton in Lake Ladoga are presented, and a comparison is made between two sampling techniques, tube sampler and plankton net, and between two counting methods. The precision of subsampling and sampling is further discussed on the basis of zooplankton data gathered in Lake Saimaa, Finland. The comparison clearly indicates that a tube sampler is required for reliable sampling of small-sized animals, while a plankton net saves time and is a more economical sampler for large, rare or active animals. The comparison between the results obtained by Finnish and Russian workers, using different counting procedures, shows that the main groups of crustacean zooplankton are similarly counted and identified in the two laboratories.     

Seasonal fluctuations in macrophyte cover and water transparency of four brown-water lakes: implications for crustacean zooplankton in littoral and pelagic habitats

The dynamics of crustacean zooplankton in the littoral and pelagic zones of four forest lakes having variable water qualities (colour range 130–340 mg Pt l⁻¹, Secchi depth 70–160 cm) were studied. The biomass of zooplankton was higher in the littoral zone than in the pelagic zone only in the lake having the highest transparency. In the three other lakes, biomass was significantly higher in the pelagic zone than in the littoral zone. In the two lakes with highest transparency, the littoral biomass of cladocerans significantly followed the development of macrophyte vegetation, and cladoceran biomass reached the maximum value at the time of highest macrophyte coverage. In lakes with lowest transparency, littoral zooplankton biomass developed independently of macrophyte density and decreased when macrophyte beds were densest. The seasonal development of the littoral copepod biomass did not follow the development of macrophytes in any of the lakes. The mean size of cladocerans in the pelagic zone decreased with increasing Secchi depth of the lake, whereas in the littoral zone no such phenomenon was detected. Seasonally, when water transparency increased temporarily in two of the lakes, the mean size of cladocerans in the pelagic zone decreased steeply. For copepods, no relationship between water transparency and body size was observed. The results suggested that in humic lakes the importance of the littoral zone as a refuge decreases with decreasing transparency of the water and that low water transparency protects cladocerans from fish predation. All the observed between-lake differences could not be explained by fish predation, but were probably attributed to the presence of chaoborid larvae with variable densities. Feeding efficiency of chaoborids is not affected by visibility and thus they can obscure the relationship between water quality, fish density, and the structure of crustacean zooplankton assemblages. Handling editor: S. I. Dodson     

Seasonal dynamics of rotifer and crustacean zooplankton populations in a eutrophic,monomictic lake with a note on rotifer sampling techniques

The abundances, biomass, and seasonal succession of rotifer and crustacean zooplankton were examined in a man-made, eutrophic lake, Lake Oglethorpe, over a 13 month period. There was an inverse correlation between the abundance of rotifers and crustaceans. Rotifers were most abundant and dominated (>69%) the rotifer-crustacean biomass during summer months (June–September) while crustacean zooplankton dominated during the remainder of the year (>89%). Peak biomasses of crustaceans were observed in the fall (151 µg dry wt l^–1 in October) and spring (89.66 µg dry wt l^–1 in May). Mean annual biomass levels were 46.99 µg dry wt l^–1 for crustaceans and 19.26 µg dry wt l^–1 for rotifers. Trichocerca rousseleti, Polyarthra sp., Keratella cochlearis and Kellicottia bostoniensis were the most abundant rotifers in the lake. Diaptomus siciloides and Daphnia parvula were the most abundant crustaceans. Lake Oglethorpe is distinct in having an unusually high abundance of rotifers (range 217–7980 l^–1). These high densities can be attributed not only to the eutrophic conditions of the lake but also to the detailed sampling methods employed in this study.The research was supported by National Science Foundation grants DEB 7725354 and DEB 8005582 to Dr. K. G. Porter. It is lake Oglethorpe Limnological Association Contribution No. 25 and Contribution No. 371 of the Harbor Branch Foundation, Inc.