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991.
IThe Phytoplankton spoteS succession is a major characteristic Of PhytOPlankton behavior inthe an, and is Of major swificance tO PhytOPlankton d~cs and in coupling the PhytOPlankton cornxnunity to hasher trophic levels (Smayda, 1980). But another conception species ence that be defined by BraarUd often confUSeS with speCies sucCeSSion. Spotes su~ is thechange of speCies compeition within a given water mass resulting from changing physical,chemical and biological factors within the wa…  相似文献   
992.
波群与单频率波的波向线的比较   总被引:1,自引:0,他引:1  
本文根据普遍几何群速的概念和Fermat原理导出的波群的波向线方程,数值计算在理想底形海域中波群与单频率波的波向线,并加以比较,指出两者的异同。同时还检验了前人的一些结论。  相似文献   
993.
海洋初级生产力的结构   总被引:11,自引:0,他引:11  
焦念志  王荣 《海洋与湖沼》1993,24(4):340-344
海洋初级生产力的研究发展到今天,其内涵和信息已不是一个简单的量值所能表达得了的,必须建立起一个能够反映其生态学意义的关于生产力结构的概念。在这个概念中,初级生产力的结构归纳为以下4个方面:(1)组分结构,即不同类群生产者(包括自养微生物、各类浮游植物等)对初级生产力贡献的比例;(2)粒级结构,即不同粒径级(<2μm,2—20μm,>20μm)生产者对初级生产力贡献的比例;(3)产品结构,即初级生产产品中颗粒有机碳(POC)和溶解有机碳(DOC)的分配比例;(4)功能结构,即新生产力占总初级生产力的比例。  相似文献   
994.
王琰  曹文达 《海洋与湖沼》1993,24(3):256-263
用GDX 102树脂从海洋浮游植物三角褐指藻(Phaeodactylum tricornutum)的分解产物和代谢产物中分离提取腐植类物质(DHS,EHS)及乙醇可溶物(DES,EES),用1H-NMR,IR和UV光谱进行结构分析,并同海水中腐植质(HS)和乙醇可溶物(ES)做了比较。结果表明,DHS,EHS和HS都以高支链烷烃、碳水化合物和氨基酸结构为主要组分,另有少量芳烃和杂环化合物。它们的化学结构很相似,说明DHS和EHS是海水腐植质的重要来源。  相似文献   
995.
该文依据 1995年 3月~ 1996年 1月间浮游植物的调查资料 ,并结合同期水温和营养盐的资料变化 ,分析不同环境因素对浮游植物群落结构的影响。结果表明 :水温的变化对浮游植物的种类组成和数量变化都有一定影响 ,秋季和冬季优势种交替明显 ;营养盐对浮游植物群落结构的变化影响明显。根据胶州湾营养盐结构的改变状况 ,并结合历史资料对比发现 ,胶州湾网采浮游植物的物种数和细胞数量呈下降趋势 ,优势种类趋单一化 ;但初级生产力并未下降 ,可能与微型浮游植物所占份额增大相关。  相似文献   
996.
The determination of heme b in marine phyto- and bacterioplankton   总被引:1,自引:0,他引:1  
Martha Gledhill   《Marine Chemistry》2007,103(3-4):393-403
A method for the quantification of heme b in marine phyto- and bacterioplankton is described. Heme b was extracted from filtered cells using a solution of 2.5% octyl β-glucopyranoside in 0.02 M ammonium hydroxide. The extract was analysed by high performance liquid chromatography diode array spectrophotometry. Maximum absorbance for heme b was at 400 nm. Heme b was separated from other pigments using a polystyrene divinyl benzene stationary phase and a gradient elution programme with 0.1% (v:v) nonafluoropentanoic acid in water and 50:50 (v:v) isopropanol:acetonitrile as the mobile phases. Heme b was quantified using Fe (III) protoporphyrin IX chloride (hemin) standards. The detection limit, calculated from 3 × s.d. of the lowest standard was 0.08 pmol or 1.57 nM with a 50 μL injection volume. The first data for heme b in marine phyto- and bacterioplankton are reported. Heme b contents are reported for the eukaryotes Thalassiosira weissflogii, Thalassiosira oceanica, Dunaliella tertiolecta and Emiliania huxleyi, and the prokaryotes Synechococcus WH8102, WH7803, RCC307, Erythrobacter litoralis, Roseobacter denitrificans and Vibrio natriegens. For T. weissflogii, T. oceanica, D. tertiolecta and E. huxleyi cellular heme b concentrations varied between 12 and 60 μmol L− 1 and chlorophyll a to heme b ratios varied between 216 and 309.  相似文献   
997.
福建湄洲湾浮游植物的分布   总被引:3,自引:2,他引:3  
林金美  杨清良 《台湾海峡》1991,10(2):122-126
本文根据1984年福建海岸带调查及1988年港湾志调查所获的样品资料,分析报道了湄洲湾海域浮游植物的种类组成、数量时空分布及其影响因子,文中共鉴定浮游植物127种,细胞总量分布为5月出现主高峰,8月为次高峰,2月为最低谷,其数量分布和季节变化与水温、盐度、海流和季风的影响密切相关。  相似文献   
998.
We analysed mixed-layer seasonal and interannual variability in phytoplankton biomass and macronutrient (NO3 and Si(OH)4) concentrations from three decades of observations, and nitrogen uptake rates from the 1990s along Line P in the NE subarctic Pacific. Chlorophyll a concentrations near 0.35 mg m−3 were observed year-round along Line P except at the nearshore station (P4) where chlorophyll a concentrations in spring were on average 2.4 times the winter values. In contrast, the temporal variability in carbon-to-chlorophyll ratios at the two main end members of Line P (P4 and OSP) was high. Large seasonal and interannual variability in NO3 and Si(OH)4 concentration were observed along Line P. Highest upper mixed-layer (top 15 m) nutrient concentrations occurred on the continental shelf in late summer and early fall due to seasonal coastal upwelling. Beyond the shelf, maximum nutrient concentrations increased gradually offshore, and were highest in late winter and early spring due to mixing by winter storms. Interannual variations in upper mixed-layer nutrient concentrations beyond the shelf (>128°W) were correlated with E-W winds and the PDO since 1988 but were not correlated with either climate index between 1973 and 1981. Despite differences in nutrient concentration, nutrient utilization (ΔNO3 and ΔSi(OH)4) during the growing season were about 7.5 μM at all offshore stations. Variations in ΔNO3 were correlated with those of ΔSi(OH)4. The annual cycle of absolute NO3 uptake (ρNO3) and NH4 uptake (ρNH4) rates by phytoplankton in the upper mixed-layer showed a weak increasing trend from winter to spring/summer for the period 1992-1997. Rates were more variable at the nearshore station (P4). Rates of ρNO3 were low along the entire line despite abundant NO3 and low iron (Fe), at the offshore portion of Line P and sufficient Fe at the nearshore station (P4). As a result, new production contributed on average to only 32 ± 15% of the total nitrogen (N) uptake along Line P. NO3 utilization in the NE subarctic Pacific is probably controlled by a combination of environmental variables, including Fe, light and ambient NH4 levels. Elevated ambient NH4 concentrations seem to decrease the rates of new production (and f-ratios) in surface waters of the oceanic subarctic NE Pacific. Contrary to expectation, phytoplankton biomass, nutrient utilization (ΔNO3 and ΔSi(OH)4), and nitrogen uptake (ρNO3 + ρNH4) varied relatively little along Line P, despite significant differences in the factors controlling phytoplankton composition assemblages and production. Future studies would benefit from including other variables, especially light limitation, to improve our understanding of the seasonal and interannual variability in phytoplankton biomass and nutrients in this region.  相似文献   
999.
Seasonal and interannual variability of chlorophyll a concentration in the Japan/East Sea (JES) was detected spatially by ocean color satellite remote sensing. Start timing of the spring bloom was different spatially. The spring bloom started at the subpolar front and southward of it in March, northward of subpolar front, along the Primorye coast and off Hokkaido in April and in the middle of the Japan Basin in May. The start of the spring bloom showed interannual variability that corresponded with the wind speed in the area. The spring bloom in 1998 and 2002 appeared about four weeks earlier than in 1997, 1999 and 2001, and it corresponded with weak winds that can lead to an early development of the thermocline. The bloom was late in 1999 and 2001 in the Japan Basin and along the Primorye coast, and in the southern area in 2000. It corresponded with stronger wind stress that delayed seasonal thermocline formation. The bloom along the Primorye coast appeared later in 1999, and it corresponded with stronger wind stress, and at the same time, it seemed to be related with the delay of melting of sea ice in Mamiya Strait. The fall bloom appeared from early October to early December, and it did not have a clear temporal transition. The area where chlorophyll a concentration exceeded 0.8 μg l−1 was wider in the western area than in the eastern area every year. The magnitude of the fall bloom was different between years, but it did not show a correlation with average wind speed in fall. Those results indicated that the timing of the seasonal bloom in the JES is largely affected by the variability of global climate such as ENSO events.  相似文献   
1000.
A theoretical framework for the time-dependent processes leading to the high rates of new production in eastern boundary upwelling systems has been assembled from a series of past upwelling studies. As part of the CoOP WEST (Wind Events and Shelf Transport) study, new production in the Bodega Bay upwelling area and it's control by ambient nitrate and ammonium concentrations and the advective wind regime are described. Data and analyses are focused primarily on the WEST 2001 cruise (May–June 2001) when the two legs differed greatly in wind regimes but not nutrient concentrations. Elevated concentrations of ammonium in upwelled water with high nitrate were observed in both legs. Nitrate uptake by phytoplankton as a function of nitrate concentration was linear rather than Michaelis–Menten-like, modulated by inhibitory levels of ammonium, yielding coefficients that enable the specific nitrate uptake element of new production to be estimated from nutrient concentrations. The range of specific nitrate uptake rates for the two legs of WEST 2001 were similar, essentially a physiological response to nutrient conditions. However, the low “realization” of new production i.e. incorporation of biomass as particulate nitrogen that occurred in this system compared to the theoretical maximum possible was determined by the strong advective and turbulent conditions that dominated the second leg of the WEST 2001 study. These data are compared with other upwelling areas using a physiological shift-up model [Dugdale, R.C., Wilkerson, F.P., Morel, A. 1990. Realization of new production in coastal upwelling areas: a means to compare relative performance. Limnology and Oceanography 35, 822–829].  相似文献   
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