中国典型海域超微型生物生态学初步研究

IOCAS-IR > 海洋环流与波动重点实验室

	中国典型海域超微型生物生态学初步研究
	杨燕辉
学位类型	博士
	2000
学位授予单位	中国科学院海洋研究所
学位授予地点	中国科学院海洋研究所
学位专业	海洋生物学
关键词	聚球藻原绿球藻超微型真核生物异养细菌病毒营养盐添加
摘要	通过流式细胞技术(FCM)调查了我国东海、南海和胶州湾的几类超微型浮游生物，包括聚球藻(Synechococcus)，原绿球藻(Prochlorococcus)，超微型真核生物和异养细菌的空间分布、季节变化及与环境因子之间的关系。开展了一系列现场实验对几种常量和微量营养元素对4类超微型浮游生物生长的影响进行了初步的研究。另外，对细胞周期法估计原绿球藻的生长率，以及用流式细胞仪分析病毒粒子的数量分布做了尝试性的工作。主要结果如下： 1 在东海黑潮区，超微型浮游植物约占叶绿素生物量的60％多，在其它海区，约占10-40％。原绿球藻的季节变化较大，冬季主要分布在黑潮流域，夏季可达50米等深线附近。在黑潮区，原绿球藻与聚球藻细胞密度的比值在10左右，在其它海区，比值为1-2。超微型浮游生物群落结构从沿岸到外海变化较复杂。在南海，平均70％多的叶绿素生物量由超微型浮游植物提供，而原绿球藻则为超微型自养浮游生物碳生物量的主要贡献者，平均约占30％。整个南海在海水性质上接近贫营养大洋海区，原绿球藻和聚球藻的细胞密度比为15～160，海盆区和岛礁区超微型浮游生物群落结构有所差别。超微型浮游生物的分布和群落结构在两个海区均受海流、水团及水柱理化性质的影响。总的看来，海流、水团的性质越接近大洋，超微型浮游生物在生态系统中的地位相对越重要，而原绿球藻在生物量和生产力上的相对贡献也越大。原绿球藻在东海的分布除受水流、水团的作用外，在冬季还受温度的限制。冬季原绿球藻大体限于黑潮流域，而夏季则可分布到50米等深线附近。从大尺度范围看，从近岸到外海，或从中营养海区到贫营养海区过渡的过程中，原绿球藻和异养细菌的丰度变化呈相反趋势，它们与聚球藻之间的变化趋势因海区的不同而存有差异，这可能是由于多品系聚球藻同时存在的原因。这些相关性在水质条件变化幅度剧烈的东海表现得显著，而在海水水质条件差别不大的南海则不明显。在垂直分布上，超微型浮游植物的分布与水柱的分层、营养状况都有关系。在上混合层较浅，硝酸盐在检测限以上的东海大部分海区，超微型浮游植物的最大层与硝酸盐跃层深度有关，而在上混合层较深，混合层中硝酸盐的浓度低于检测限的南海海盆区，原绿球藻的高值分布似乎与氨氮的浓度有关。小尺度范围内超微型浮游生物的数量和群落结构的变化不仅与温度，营养盐浓度有关，还与水柱的物理结构(如混合层发育的情况)有关。 2 南海营养盐添加实验表明，原绿球藻似乎更受磷限制，而聚球藻和超微型真核生物对铵氮的添加反应更明显。在生理上，原绿球藻与聚球藻和超微型真核浮游植物有明显差别，后两者对营养盐添加的反应接近。原绿球藻对钴添加的反应大于铁添加的反应，而后两者则对铁添加的反应较强。在某些营养生理特性上，原绿球藻似乎更接近异养细菌。 75米层海水铁添加实验表明，不同浓度的铁均促进nano一级的浮游植物的生长；对于超微型浮游植物来说，纳摩尔级铁的添加有利于超微型真核生物的生长，而更高浓度的铁添加则对聚球藻和原绿球藻的生长有利。虽然钴的加入有利于原绿球藻的生长，但是维生素B_(12)的加入对其生长无明显的影响，说明钴在原绿球藻的生理代谢过程中可能有合成维生素B_(12)以外的作用。钴的添加对聚球藻的生长无明显影响，但不同浓度的维生素B_(12)的添加均能促进聚球藻的生长，说明火洋中的聚球藻品系可能不能自己合成该种维生素。无论是钴还是维生素B_(12)对超微型真核生物的生长均无显著的影响。钼与铁均参与硝酸盐的还原和固氮作用，但钼的添加只对聚球藻有明显的促进作用，对其它几类超微型浮游生物的影响不明显。 3 现场培养实验表明，原绿球藻在生理上能耐受的温度下限比其自然分布的温度下限更低，说明冬季限制原绿球藻向近岸分布的是多种环境因子共同作用的结果。实验表明，种间相互作用，微量金属元素，以及水体的物理化学条件等都是制约原绿球藻近岸分布的因素。 4 细胞周期法估计南海75米层原绿球藻的生长率为0.54／天。 5 流式细胞仪在东海东部检测一类病毒粒子的数量在10~5／毫升的数量级。尽管这类病毒粒子在垂直分布上与自养细胞的分布有关，但是在水平分布上却与异养细菌数量的变化相关性最显著。 6 胶州湾超微型浮游植物主要出聚球藻和超微型真核生物组成。聚球藻的细胞浓度在夏季最高，冬季细胞浓度最低，平均为1.4 8*10~3细胞／毫升，并与温度变化的关系最明显。超微型真核生物细胞浓度的季节变化不如聚球藻规律。从全年变化的角度来看，超微型浮游植物在胶州湾生态系统中占有重要的地位，而超微型真核生物是超微型浮游植物生物量的主要提供者。
其他摘要	Spatial distributions and seasonal variations of cell abundances of Synechococcus (Syn), Prochlorococcus (Pro), picoeukaryote (Euk) and heterotrophic bacteria (Bact) in the East and South China Seas, and the Jiaozhou Bay were investigated by flow cytometry. Relationships between the four groups of picoplankton and some environmental factors were discussed. In situ nutrient enrichment experiments were performed on board the investigation vessel. Attempts were made on estimating the growth rate of Prochlorococcus through the cell cycle approach, and abundance of marine virus was measured by flow cytometry. The main results are as follow: 1 In the East China Sea, picoplankton with cell size less than 2 μm accounted for about 40% of the bulk chlorophyll a (Chl a) biomass. Among them, Syn were the most important contributor. Cell abundance ratios of Pro: Syn were about 10. In the South China Sea, more than 70% of Chl abiomass were contributed by the picoplankton fraction. Carbon biomass of Pro accounted for about 30% of the total carbon biomass of the picoplankton community in the South China Sea. Cell abundance ratios of Pro : Syn ranged between 15～160. Picoplankton community structures were different in the sea basin area from in the Nansha Islands sea area. Distribution of picoplankton and the species composition of the Spatial distributions and seasonal variations of cell abundances of Synechococcus (Syn), Prochlorococcus (Pro), picoeukaryote (Euk) and heterotrophic bacteria (Bact) in the East and South China Seas, and the Jiaozhou Bay were investigated by flow cytometry. Relationships between the four groups of picoplankton and some environmental factors were discussed. In situ nutrient enrichment experiments were performed on board the investigation vessel. Attempts were made on estimating the growth rate of Prochlorococcus through the cell cycle approach, and abundance of marine virus was measured by flow cytometry. The main results are as follow: 1 In the East China Sea, picoplankton with cell size less than 2 μm accounted for about 40% of the bulk chlorophyll a (Chl a) biomass. Among them, Syn were the most important contributor. Cell abundance ratios of Pro: Syn were about 10. In the South China Sea, more than 70% of Chl abiomass were contributed by the picoplankton fraction. Carbon biomass of Pro accounted for about 30% of the total carbon biomass of the picoplankton community in the South China Sea. Cell abundance ratios of Pro : Syn ranged between 15～160. Picoplankton community structures were different in the sea basin area from in the Nansha Islands sea area. Distribution of picoplankton and the species composition of the picoplankton were affected by the currents, water masses and the physical and chemical features of the water column. Picoplankton were more important in the open water areas than in the nutrient repleted coastal waters. In winter, the distribution of Pro was limited mainly within the Kuroshio current area, most probably by temperature. In summer, distribution of Pro paralleled the 50m isobath, presenting in most areas of the East China Sea. From a large scale, cell abundances of Pro and Bact varied in an opposite way when going from coastal to the open sea areas. Vertical distribution patterns of picoplankton were affected by both chemical and physical status, such as stratification of the water column. In the East China Sea where there was shallower upper mixing layer, and nitrate was detectable, the depth of the maximum layers of picoplankton followed the nitracline. Whereas in the basin area of the South China Sea, upper mixing layer was generally deeper and usually with undetectable nitrate, maximum layer of Pro seemed to have something to do with the distribution of ammonia. 2 Nutrient enrichmenl experiments in the South China Sea suggested that, Syn and Euk were similar in characteristics of high demanding for Fe and N. On the other hand, Pro responded more to Co and P than to Fe and N. In 75m in the South China Sea, Fe enriched from a large range of concentrations stimulated the growth of nanoplankton. For the picoplankton, Fe enrichment of nano-molar level increased the cell abundance of Euk, on the other hnad, Syn and Pro had significant responses to higher concentration of Fe enrichment. Although Co stimulated the growth of Pro, vitarnin B_(12) had little influence on Pro, indicating that Co functioned other than V_(B12) synthesis in metabolism processes of Pro. Effects of Co and V_(B12) enrichment on Syn were just the opposite. Both of the two micronutrients had little effects on Euk. Molybdenum only stimulated the growth of Syn significantly, and had little effect on the other groups of picoplankton. 3 Results from a series of in situ experiments suggested that, Pro could survive at temperatures lower than the temperature limit of the winter distribution in the East China Sea. Biological interactions, trace metal, and chemical and physical conditions of the water column might all be the potential factors limiting the distribution of Pro to the coastal area. 4 Growth rate of Pro at 75m depth estimated by the cell cycle method was 0.54 d~(-1). 5 Abundance of one group of virus was measured by flow cytometer in the eastern East China Sea in May, 1999. Vertical distribution of this group of virus correlated significantly with those of the autotrophes, however, its horizontal distribution correlated significantly with that of Bact, but not the autotrophes or the bulk Chl aconcentration. 6 Picoplankton in the Jiaozhou Bay were mainly Syn and Euk. Cell abundance of Syn was high in summer and low in winter. Cell abundance of Euk were less temperature-dependent. Picoplankton accounted for a considerable percentage of the total Chl a biomass in the Jiaozhou Bay ecosystem, among the picoplankters, eukaryotes were more important than prokaryotes in terms of biomass. picoplankton were affected by the currents, water masses and the physical and chemical features of the water column. Picoplankton were more important in the open water areas than in the nutrient repleted coastal waters. In winter, the distribution of Pro was limited mainly within the Kuroshio current area, most probably by temperature. In summer, distribution of Pro paralleled the 50m isobath, presenting in most areas of the East China Sea. From a large scale, cell abundances of Pro and Bact varied in an opposite way when going from coastal to the open sea areas. Vertical distribution patterns of picoplankton were affected by both chemical and physical status, such as stratification of the water column. In the East China Sea where there was shallower upper mixing layer, and nitrate was detectable, the depth of the maximum layers of picoplankton followed the nitracline. Whereas in the basin area of the South China Sea, upper mixing layer was generally deeper and usually with undetectable nitrate, maximum layer of Pro seemed to have something to do with the distribution of ammonia. 2 Nutrient enrichmenl experiments in the South China Sea suggested that, Syn and Euk were similar in characteristics of high demanding for Fe and N. On the other hand, Pro responded more to Co and P than to Fe and N. In 75m in the South China Sea, Fe enriched from a large range of concentrations stimulated the growth of nanoplankton. For the picoplankton, Fe enrichment of nano-molar level increased the cell abundance of Euk, on the other hnad, Syn and Pro had significant responses to higher concentration of Fe enrichment. Although Co stimulated the growth of Pro, vitarnin B_(12) had little influence on Pro, indicating that Co functioned other than V_(B12) synthesis in metabolism processes of Pro. Effects of Co and V_(B12) enrichment on Syn were just the opposite. Both of the two micronutrients had little effects on Euk. Molybdenum only stimulated the growth of Syn significantly, and had little effect on the other groups of picoplankton. 3 Results from a series of in situ experiments suggested that, Pro could survive at temperatures lower than the temperature limit of the winter distribution in the East China Sea. Biological interactions, trace metal, and chemical and physical conditions of the water column might all be the potential factors limiting the distribution of Pro to the coastal area. 4 Growth rate of Pro at 75m depth estimated by the cell cycle method was 0.54 d~(-1). 5 Abundance of one group of virus was measured by flow cytometer in the eastern East China Sea in May, 1999. Vertical distribution of this group of virus correlated significantly with those of the autotrophes, however, its horizontal distribution correlated significantly with that of Bact, but not the autotrophes or the bulk Chl aconcentration. 6 Picoplankton in the Jiaozhou Bay were mainly Syn and Euk. Cell abundance of Syn was high in summer and low in winter. Cell abundance of Euk were less temperature-dependent. Picoplankton accounted for a considerable percentage of the total Chl a biomass in the Jiaozhou Bay ecosystem, among the picoplankters, eukaryotes were more important than prokaryotes in terms of biomass.
页数	248
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/905
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	杨燕辉. 中国典型海域超微型生物生态学初步研究[D]. 中国科学院海洋研究所. 中国科学院海洋研究所,2000.

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