排序方式: 共有18条查询结果,搜索用时 15 毫秒
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根据1986~1987年逐月调查和1987年以来结合教学实习采集的朱家尖海滨底栖无脊椎动物资料,并参考前人对该岛的调查,叙述了朱家尖岛海滨底栖无脊椎动物10门257种,分析了生活潮区、栖息底质等,提出了该岛潮间带生物资源保护的建议。 相似文献
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太湖流域大型底栖动物生物完整性研究 总被引:6,自引:0,他引:6
于2009年8月对太湖流域32个采样点的大型底栖动物和水环境因子进行了调查采样.选取太湖流域大型底栖动物的物种数、物种相对丰度、敏感-耐污类群组成、功能摄食类群和多样性指数等共22个参数作为构建太湖流域大型底栖动物生物完整性评价体系的候选参数.通过对候选参数在参考点位(8个)和受损点位(19个)之间的比较,最终确定了总分类单元数(total taxa)、摇蚊科分类单元数(chironomidae taxa)、甲壳+软体动物分类单元数(crustaceanmollusc taxa)、前3位优势分类单元相对丰度(top three of dominant taxa)以及香农威纳多样性指数(shannon-wienerindex)为构建评价体系的参数.通过比值法计算得到太湖流域各个采样点的生物完整性得分.在太湖流域监测的站点中7个为健康,7个为亚健康,6个为一般,5个为较差,3个为极差.Pearson相关性分析显示,B-IBI得分同亚硝酸氮、氨氮呈显著性负相关(P0.05). 相似文献
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Yonghua Wu Xuefa Shi Jianjun Zou Zhenbo Cheng Kunshan Wang Shulan Ge Fengdeng Shi 《科学通报(英文版)》2014,59(24):3066-3074
A total of six d13C minimum events,i.e.,VI,V,IV,III,II,and I,were observed via a stable carbon and oxygen isotope analysis of infaunal benthic foraminifera Uvigerina spp.in gravity core OS03-1 in the southeastern Okhotsk Sea over the last 180 ka.These events occurred at112–109,102–90,85–76,57–54,44–40,and 17–10 ka BP.The largest negative excursions reached 2.5%in event V and were greater than 1%in the other events.We proposed that all d13C minimum events were caused by the increase in sea surface water productivity,the weakened formation of Okhotsk Sea intermediate water,and the enhancement of the oxygen minimum zone.The negative excursions were unaffected by methane hydrate destabilization and subsequent methane release based on the results obtained by using archaeal lipid markers. 相似文献
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为了解长江中游宜昌至武汉段底栖动物的群落结构特征以及主要影响因素,分别于2014年春季(4月)和秋季(10月)在该江段布设4个断面(共29个采样点)和5个断面(共40个采样点),进行底栖动物群落监测。春季采集到底栖动物34种,秋季采集到32种,均是节肢动物丰度最高,分别为56%和35%。春季物种丰度、密度和生物量均大于秋季,且春、秋季生物量自上而下逐渐减小。功能摄食类群研究结果表明,该江段底栖动物以牧食者占绝对优势,春、秋季牧食者个体数占总个体数的比例分别为40.25%和59.3%。生物耐污能力统计结果表明,该江段以中等敏感类群和耐污类群为主,武汉断面在两个季节中均以耐污类群为主。5种功能摄食类群以及三大门类生物现存量与7个环境因子的相关性分析结果表明,春、秋季生物受环境因子的影响差异较大,总磷、总氮和粒径是影响春季底栖动物群落结构特征的主要环境因子,而秋季底栖动物主要受p H、溶解氧和透明度的影响。该研究从多个方面较全面地分析长江中游江段底栖动物群落特征,为开展长江大河深层次研究提供基础性资料。 相似文献
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北运河水系大型底栖动物摄食功能群多样性及时空分布特征 总被引:1,自引:0,他引:1
目的为分析北运河水系不同季节大型底栖动物的时空分布特征,2015年春季(5月)、夏季(8月)和秋季(11月)对北京地区相同的17个采样点位的大型底栖动物群落结构和水环境因子特征进行了调查.方法基于香浓维纳指数、均匀度指数、大型底栖动物功能摄食类群的划分以及典范对应分析等方法,分析了大型底栖动物功能摄食类群组成和空间结构特征.结果春季、夏季和秋季采集到大型底栖动物19、20和21种,密度平均值为1.79×103、1.14×103和0.63×103 ind·m-2;香浓维纳指数平均值分别为1.01、1.30和1.80;均匀度指数平均值分别为0.36、0.32和0.55.全地区共划分出大型底栖动物功能摄食类群5类,3个季节中滤食者和收集者密度均占绝对优势.典范对应分析表明,春季影响北运河水系大型底栖动物功能摄食类群的主要环境因子是氨氮和pH;夏季影响北运河水系大型底栖动物功能摄食类群的主要环境因子是氨氮;秋季影响北运河水系大型底栖动物功能摄食类群的主要环境因子是水温.结论北运河水系水体受到了一定污染. 相似文献
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《Journal of Natural History》2012,46(43-44):2675-2687
Studies on freshwater invertebrate fauna on islands are rare but a few suggest species richness can be high. A survey of the freshwater invertebrates of Lord Howe Island (LHI) yielded 38 taxa, bringing the total recorded from LHI to 54. The majority of the taxa from the survey were from the Insecta, with 15 Diptera (true flies), five hemipterans (true bugs) and five trichopterans (caddisflies). Two species of gastropods, three mites and eight other arthropods were also found. The total number of taxa on LHI, although smaller than other islands, is the highest per unit area ever recorded (3.9 taxa per km2). High levels of endemism were recorded for most taxonomic groups and two previously undescribed chironomid species were found. However, further taxonomic and genetic work is necessary in order to assess true levels of endemism by investigating the genetic similarities and differences of these taxa with nearby islands. 相似文献
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《Journal of Natural History》2012,46(10):1179-1197
Explorations by the German Research Vessel Sonne in the fore-arc and back-arc basins of the western Pacific Ocean have collected vestimentiferan tube worms from both warm vent and cold seep sites. Edison Seamount is a small volcanic cone on the southern flank of Lihir Island, in the Tabar-Feni island chain. Beds of vesicomyid clams on the summit (1450 m depth) are associated with hydrothermal effluent, whereas an uplifted scarp (1600 m depth) nearby is covered by low temperature gas-rich sediments. A methane anomaly has been detected in the water column above the scarp. The benthic fauna includes vestimentiferan tubeworms and bathymodiolid mussels. Bottom photographs show that the vestimentiferans occur singly or in small groups. Four specimens were collected by TV-guided grab. They are described as a new species of a new genus, related to the cold-seep genus Escarpia, of the family Escarpiidae. A single specimen obtained from the landward slope of the Java Trench (1500m) is identified as the same species, extending its area of distribution by some 6000 km westward. Arcovestia ivanovi, already known from hydrothermal vents in the Manus Basin, has now been obtained from a hydrothermal site in the North Fiji Basin. 相似文献
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底栖硅藻新月筒柱藻对锌胁迫的生理学效应 总被引:1,自引:0,他引:1
采用流式细胞仪检测细胞增长与色素含量、原子火焰吸收光谱法测定金属含量以及显微镜观察细胞状态等方法研究了红树林底栖硅藻新月筒柱藻(Cylindrotheca clostetium(Ehr.)Reimann and Lewin)暴露在重金属锌96h内的细胞增长、光合色素含量和细胞形态结构等胁迫效应,以及锌在藻细胞内外动态分布的情况.结果为:(1)在Zn^2+浓度小于10mg/L范围内,锌对新月筒柱藻的细胞增长和色素含量均无显著抑制作用.(2)1mg/L和10mg/L的Zn^2+对藻细胞内的叶黄素和叶绿素a的产生都有促进作用.(3)在实验开始的24h内,藻细胞处在低Zn^2+浓度(1mg/L)时,藻细胞胞内吸收的Zn^2+大于胞外吸附的Zn^2+.而藻细胞处在高Zn^2+浓度(10mg/L)时,胞外吸附的Zn^2+较胞内吸收的大,细胞内Zn^2+的含量处在较低水平,从而促进细胞的增长和色素的合成并使细胞免受外界高浓度锌的毒害.可见,新月筒柱藻正是通过改变对锌的富集方式,以保持细胞内锌含量的相对稳定来适应不同浓度锌的胁迫. 相似文献
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Nematodes are small multicellular, thread-like organisms, inhabiting almost all conceivable environments; among these, some 25 % are free-living marine forms with a population density of (1-12) × 10^6 inds m^-2 in seabed sediment, reaching maximum values in muddy estuaries and salt marshes. A large quantity of carbon from the salt marsh plants enters the ecosystem via the detritus pathway, in which nematodes play an important role through their feeding and bioturbation activities. Vegetation influences the sedimentary environment and modifies the distribution pattern of nematode communities in coastal wetlands. Nematodes are coupled closely with bacteria/detritus in microbial food webs, stimulating bacterial growth and subsequent nutrient remineralization; they provide food sources for higher trophic levels and serve as a linkage between micro- and macro-fauna. Furthermore, nematodes have a potential to provide proxies that can be used in diagnosing environmental quality. In China, only a limited number of nematode data sets are available for the coastal wetlands across several different climatic zones. It is necessary to carry out additional investigations into the biology and ecology of nematodes in order to delineate their ecological functioning in coastal wetlands. On such a basis, the contribution made by nematodes to material cycling and the ecological functioning in coastal wetlands can be quantified. The assessment of their biological diversity should be a focus, which is fundamental in the study of wetland ecosystem dynamic mechanisms. In addition to laboratory and mesocosm experiments, mathematical models should be established to predict the responses of ecosystem to the environmental disturbance. Finally, it is necessary to improve the techniques for nematode analysis, to enhance the efficiency of data acquisition. 相似文献