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模拟浮游生物的季节变化   总被引:6,自引:0,他引:6  
本文讨论了海洋中光合作用过程和计算光合作用的速率方程。运用垂直平均值的浮游生物模型研究了在一个固定站和扩展湾流体系中,浮游植物、浮游动物和营养盐的季节变化。结果表明,夹卷过程将含营养盐丰富的中层水带入了混合层,从而导致浮游植物的生长;摸式较好地给出了扩展湾流体系中的水华季,基本上得到了浮游生物的生活周期。使用不同的参数值进行了若干实验,并对结果进行了讨论。  相似文献   

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越冬池冰下浮游生物的研究   总被引:4,自引:0,他引:4  
越冬池冰下浮游植物主要由光甲藻、隐藻、小环藻、壳虫藻、衣藻、棕鞭藻等优势属组成,重点试验池平均生物量为38.8±13.06毫克/升。与明水期相比其种数较少而现存量不低;原生动物、桡足类和轮虫类构成冰下主要浮游动物。重点池平均生物量为6.21±6.52毫克/升,其中轮虫量最高。冰下浮游植物量各水层不同,86.7%的越冬池表层多于底层,另13.3%底层多于表层。光甲藻等鞭毛藻有明显的昼夜垂直移动。冰下浮游生物量有月变化和年变化,文中分析了引起这些变化的生态因素,同时探讨了与生物增氧有关的几个问题。  相似文献   

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中生代海相双壳类(软体动物)的漂浮与假漂浮   总被引:1,自引:1,他引:1  
沙金庚 《古生物学报》2003,42(3):408-416
中生代很多海相足丝固着和粘结固着的表栖双壳类有着广泛的、甚至全球的地理分布,有些种能够穿越赤道,跨越特提斯海,进行南、北高纬度生物群的交流,有些种能够由东向西横渡浩瀚的古太平洋进行扩散,因为这些双壳类幼虫期的浮游异养型幼虫能营漂浮生活,而幼虫期后的个体又能挂系或粘结在其它漂浮或移动的物体上进行假漂浮迁移。  相似文献   

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THE OCCURRENCE OF PLEODORINA IN THE FRESH WATER PLANKTON OF CEYLON.   总被引:1,自引:1,他引:0  
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SULFUR: THE PLANKTON/CLIMATE CONNECTION   总被引:1,自引:0,他引:1  
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The distributional patterns of diatoms in the plankton of the Yaqnina Estuary, Oregon, were, investigated and related to selected climatic and hydrographic factors. Distribution was strongly influenced by seasonal patterns of rainfall resulting in the introduction of a large volume of fresh water into the estuary during fall and winter. Plankton assemblages in spring, summer and fall had fewer diatom species and exhibited a more rapid rate of change in species composition than in winter. Winter assemblages were further characterized by many pennate diatoms, apparently dislodged from the benthos during periods of high freshwater discharge and silt loads. A statistical measure of community difference indicated an increase in taxonomic homogeneity among assemblages throughout the estuary with the onset of the rainy season in late fall and a gradual transition to a more heterogeneous system again during late spring. Canonical correlation ordered 20 prominent diatom taxa along the salinity gradient and identified possible relationships among certain taxa and selected environmental variables, namely visible light energy and temperature. Redundancy in the species data given the environmental data was only 40%, emphasizing the difficulty in demonstrating a quantitive relationship between plankton dynamics in the field and concurrent measurements of chemical and physical variables.  相似文献   

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DINOFLAGELLATE CYSTS IN THE PLANKTON   总被引:1,自引:1,他引:0  
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世界鹤类系统检索   总被引:1,自引:0,他引:1  
本文把全世界的15种鹤,加以全面的系统检索。对鹤类不仅从其外观形态特征,而且从比较解剖及声调等,进行检索。这样做,认为还是首次的。  相似文献   

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Living cells of the diatom Ethmodiscus rex (Rat-Iray) Wiseman & Hendey 1953 were found in the plankton of the southern Sargasso Sea. Apparently, this is the first report, of E rex from the plankton of the Atlantic Ocean. Scanning electron microscopy of peroxide-cleaned frustules revealed, some new morphological features for this species. When viewed, from inside the frustule, the puncta appear as rimmed pits. From outside the frustule, they appear to he shallow depressions with a small opening at the bottom. The so-called mucous tubules in the center of the valve were seen from the out side to be elongate slits and from the inside as obliquely directed flattened cylinders which cap the tubes.  相似文献   

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