利用稳定同位素(15N)示踪技术研究浮游藻类氮素吸收速率特征     

韩菲尔  赵中华  李大鹏  张路 《海洋与湖沼》2019,50(4):811-821

浮游藻类对溶解态氮的吸收同化是湖泊氮生物循环和水体富营养化发生机制探讨的关键环节。本文通过~(15)N稳定同位素添加实验以铜绿微囊藻(Microcystis aeruginosa)、海链藻(Thalassiosira sp.)、卡德藻(Tetraselmis sp.)、剧毒卡尔藻(Karlodinium veneficum)以及盐水隐藻(Rhodomonas salina)为研究对象,从浮游藻类氮素吸收时间、营养盐基质以及藻种差异三个方面研究五种藻类对铵氮(NH_4~+-N)、硝氮(NO_3~--N)、尿素氮(Urea-N)三种形态氮的吸收特征。研究发现:(1)浮游藻类对三种形态氮的吸收均在1h时吸收速率最高,其氮素吸收过程为快速吸收。(2)浮游藻类优先吸收还原态氮,其中NH_4~+-N吸收速率最高,当培养周期为1d和4d时浮游藻类对NH_4~+-N吸收速率的均值分别为4.05和4.15μmol/(L·h);浮游藻类对Urea-N吸收相对偏好系数为25.18—713.42,表现出对小分子溶解态有机氮的特定偏好性。(3)不同藻种对氮素吸收具有不同特征,其中,剧毒卡尔藻对三种形态氮的吸收速率均为最高,而铜绿微囊藻的吸收速率均为最低;不同藻种不同培养时间氮素吸收速率差异与浮游藻类生长周期等特性有关。不同浮游藻类对不同形态氮素表现出吸收特异性,对水体氮负荷和浮游藻类水华优势种形成将产生重要影响。  相似文献   

Two New Fossil Lacewing Species from the Middle Jurassic of Inner Mongolia, China (Neuroptera: Grammolingiidae)   总被引：2，自引：0，他引：2  

SHI Chaofan  YANG Qiang  REN Dong 《《地质学报》英文版》2011,85(2):482-489

Two new species of lacewings are described and illustrated from the Jiulongshan Formation (Middle Jurassic) of Inner Mongolia, China: Leptolingia calonervis sp. nov. and Litholingia ptesa sp. nov. (Grammolingiidae). The species can be distinguished by the following features: the outermost branch of MP2 on the hind wing did not reach the margin of wing in Leptolingia calonervis sp. nov.; the second branch of Rs forked deeply while other branches of Rs forked much later in Litholingia ptesa sp. nov..  相似文献   

New Fossil Xyelidae (Insecta, Hymenoptera) from the Yixian Formation of Western Liaoning, China   总被引：1，自引：0，他引：1  

GAO Taiping  ZHAO Yunyun  REN Dong 《《地质学报》英文版》2011,85(3):528-532

In this paper one new genus and two new species, Brachyoxyela brevinodia sp. nov. and Brachyoxyela gracilenta sp. nov., in the subfamily Macroxyelinae of the family Xyelidae, are described and illustrated. The specimens were collected from the Yixian Formation, the Upper Jurassic to Lower Cretaceous, of Beipiao City, Liaoning Province, northeastern China. The new genus is established based on the characters that vein Sc meets R only beyond origin of Rs, third antennal segment is almost equal in length to the rest flagellomeres combined, terminal flagellomeres increasingly shortened toward apex, and vein 2r-rs inclined toward the apex of wing.  相似文献   

矿床原生地球化学晕分带性研究   总被引：1，自引：0，他引：1  

邢利琦  刘炳璋 《四川地质学报》2011,(4):489-492,495

矿床原生地球化学晕的分带性,可以反映出成矿成晕元素在成矿地球化学过程中于空间上的积聚规律,对找矿勘探、深部预测和矿床剥蚀程度的判断具有重要意义.在此以岔河锡矿为例进行分析,主要介绍和推荐关于岩浆气液矿床原生晕指示元素分带方向及分带序列的计算方法,用于勘查地球化学、矿产地质和潜在资源量预测工作中.  相似文献   

海岸线变化的地质指标体系   总被引：2，自引：0，他引：2  

王祎萍  李瑞敏  王轶  曹峰  徐为 《地质通报》2011,30(11):1752-1756

海岸带地质环境的演化集中表现是海岸线的变迁。基于对海岸线变迁的影响、演化方式、危害、防治对策等因素的分析,建立影响-状态-结果（CSR）的海岸线变迁的调查指标体系。在调查指标体系的基础上,抽取压力、状态、应对（PSR）指标, 建立中国海岸线变迁的监测指标体系。这对科学评价、监测和管理海岸带的环境具有重要意义。  相似文献   

Influence of submersion season on the development of test panel biofouling communities in a tropical coast     

S. Satheesh  S.G. Wesley 《Estuarine, Coastal and Shelf Science》2011,94(2):155-163

The effect of test panel submersion season on the colonization of biofouling communities in a tropical coast revealed that the effects of panel submersion time should be taken into consideration for modelling fouling community recruitment dynamics in coastal systems or during the field trials of antifouling coatings. Wooden test panels fitted onto a raft were submerged during pre-monsoon, monsoon and post-monsoon seasons for the development of the biofouling community. Results showed considerable variation in the colonization of fouling communities on test panels submerged during different seasons. Barnacles, tubeworms, ascidians and seaweeds were the major fouling communities that colonized the test panels. The total biomass of the fouling communities that settled on the post-monsoon season panels varied from the initial value of 2.72 g dm⁻² to a maximum of 44.5 g dm⁻². On the panels submerged during monsoon season, the total biomass of fouling communities varied between 0.78 g dm⁻² and 69.9 g dm⁻². The total fouling biomass on the pre-monsoon season panels varied between 2.95 and 33.5 g dm⁻². Barnacles were the initial colonizers on the panels submerged during pre-monsoon and post-monsoon seasons. Soft-bodied organisms such as ascidians dominated the monsoon season-initiated panel series during the initial period.  相似文献   

Size-differential feeding in Pinna nobilis L. (Mollusca: Bivalvia): Exploitation of detritus,phytoplankton and zooplankton     

John Davenport  Daria Ezgeta-Balić  Melita Peharda  Sanda Skejić  Živana Ninčević-Gladan  Slavica Matijević 《Estuarine, Coastal and Shelf Science》2011

The endangered fan shell Pinna nobilis is a large bivalve mollusc (<120 cm shell length) endemic to the Mediterranean that lives one-third buried in soft substrata, generally in shallow coastal waters. We hypothesised that P. nobilis of different sizes would ingest different food sources, because small fan shells will inhale material from closer to the substratum than do large fan shells. We studied stomach contents and faeces of 18 fan shells, 6 small (mean 23.0 cm length), 6 medium-sized (mean 41.5 cm length) and 6 large (mean 62.7 cm length) living in a small area of a low-energy coastal detritic bottom characterised by mud, sand and macroalgae at Mali Ston Bay, Croatia. We found that all P. nobilis ingested copious quantities of undetermined detritus (probably at least 95% of ingested material), phytoplankton, micro and mesozooplankton and pollen grains. Large P. nobilis stomach contents showed a preponderance of water column calanoid copepods, while small fan shells had higher numbers of bivalve larvae. All fan shells took in high numbers of harpacticoid copepods that are benthonic, feeding on microbial communities of detritus and benthic vegetation. There was also a significant selection of phytoplankton species, some apparently occurring between inhalation and ingestion. The stomach contents of small P. nobilis had a higher organic matter content than either medium-sized or large fan shells; this indicated that small fan shells ingested detritus of higher organic content than did larger P. nobilis. As the faeces of all P. nobilis had similar organic matter content, this also indicates higher assimilation efficiencies in small fan shells. The demonstration of differential dietary selectivity by different sized animals has implications for future trophic studies of this endangered species. This study also provides the first demonstration of predation on zooplankton by P. nobilis.  相似文献   

Emerging fisheries,emerging fishery interactions with sea turtles: A case study of the large-mesh gillnet fishery for flounder in Pamlico Sound,North Carolina,USA     

Barbie L. Byrd  Aleta A. Hohn  Matthew H. Godfrey 《Marine Policy》2011

Emerging fisheries and changes in fishery practices are not always readily apparent, nor are their impacts on non-target species such as seabirds, sea turtles, and marine mammals. Data from several different sources led managers to discover high rates of sea turtle bycatch in an inshore large-mesh gillnet fishery in North Carolina, USA, particularly the emerging deep-water gillnet fishery. This paper reviews the history of how increased numbers of observed stranded sea turtles in 1999 led to the discovery that turtles were becoming entangled in the large-mesh gillnet fishery in Pamlico Sound, North Carolina. It also demonstrates how a variety of data sets from fisheries observers, aerial surveys, and fisheries statistics programs contributed to shaping management of the large-mesh gillnet fishery in Pamlico Sound to decrease turtle bycatch and now point towards the need of additional assessment of gillnet bycatch in other parts of North Carolina. Finally, potential approaches are discussed for a more timely detection of future fishery conflicts and development of a plan to reduce otherwise inevitable bycatch and disruptions to fishing effort.  相似文献   

湄洲湾多毛类物种多样性及生态特点     

方少华  张跃平  骆巧琦  吕小梅 《台湾海峡》2011,30(3):419-429

于2007年5月至2010年5月间,在湄洲湾海域设置50个浅海测站,16条软相潮间带断面,进行底栖生物调查,根据调查采获的多毛类动物样品进行整理,研究湄洲湾多毛类物种多样性及生态特点．湄洲湾海域共鉴定有多毛类环节动物177种,隶属4l科112属．湄洲湾多毛类的动物区系特点与台湾海峡具有相似的热带、亚热带特征．讨论多毛类环节动物在调查区域底栖生物种类及数量组成中的地位,分析调查区域多毛类多样性指数等生态特征,为湄洲湾的生态环境监控、环境保护提供多毛类生态学的资料．  相似文献   

福建省主要海湾浮性鱼卵和仔稚鱼的种类组成与丰度分布     

张跃平 《台湾海峡》2011,30(2):234-242

根据2007年8月至2009年10月期间在福建省主要海湾的调查资料,对其浮性鱼卵和仔稚鱼的种类组成与数量分布特点进行初步研究和探讨.结果表明,本调查海域共出现鱼卵和仔稚鱼68种,隶属于29科,主要是近海中上层鱼类、浅海底层鱼类和港湾河口型鱼类3个生态类型.各站鱼卵总平均丰度是497.5粒/网,仔稚鱼总平均丰度50.8个/网.优势种明显,占总量比例大;不同季节和不同海湾的种类数相差不大;数量平面分布呈现不同季节不同海湾差别较大,规律性不强,偶然性大等特点.  相似文献