南海北部陆坡夏秋季浮游生物群落标准化粒径谱研究

	南海北部陆坡夏秋季浮游生物群落标准化粒径谱研究
	张文静
学位类型	硕士
导师	孙晓霞
	2016-05-18
学位授予单位	中国科学院大学
学位授予地点	北京
学位专业	海洋生态学
关键词	南海陆坡区浮游生物群落标准化粒径谱季节变化昼夜变化水平变化垂直变化
其他摘要	南海是典型的寡营养环境，表层水的营养盐浓度和浮游植物生物量都很低。而南海陆坡区有着庞大的中层鱼生物量，中层鱼类的重要饵料来源是浮游生物。南海北部陆坡区的浮游生物群落的结构组成和能量流动受到我们的关注。个体粒径是浮游生物非常重要的指标之一，它可以表征浮游生物的生理和生态学过程。近年来，以粒径为基础的浮游生物标准化粒径谱(Normalized Biomass Size Spectra, NBSS)为浮游生物的群落结构和能量流动研究提供了便捷有效的研究手段。浮游生物标准化粒径谱的斜率可以表征浮游生物群落的结构组成、大小型浮游生物的生物量比和生态转换效率的高低。浮游生物粒径谱是当前国际浮游生物群落研究方法的热点之一，在国内展开的研究尚少，在国外研究中对陆坡区域的研究也很少见。本文利用浮游生物标准化粒径谱对南海北部陆坡区浮游生物群落结构和能量流动进行研究。本研究中，夏秋季节用大、中、小型浮游生物网和多联网采集浮游生物样品，分析了夏秋季节200m以浅水层浮游生物群落结构特征，同时构建了夏秋季节200m以浅水层浮游生物标准化粒径谱和最深至1500m水层的各水层浮游生物标准化粒径谱。据此，我们研究了南海北部陆坡区浮游生物标准化粒径谱的季节变化、昼夜变化、水平变化和垂直变化特征，对南海北部陆坡区浮游生物群落能量流动情况与其他热带、亚热带海域的情况进行比较，同时分析了浮游生物标准化粒径谱斜率与环境因子的关系，结果表明：南海北部陆坡区，夏季浮游植物群落中共有39个类群，优势类群为角毛藻属(Chaetoceros)，根管藻属(Rhizosolenia)，针杆藻属(Synedra)，海线藻属(Thalassionema)，舟形藻属(Navicula)和颤藻属(Oscillatoria)；浮游植物的平均丰度为3.74×10⁴个/m³；类群多样性指数为2.87，均匀度指数为0.70。浮游动物群落共有16个类群，优势类群为桡足类(Copepoda)，被囊类(Tunicate)，腹足类(Gastropod)和端足类(Amphipoda)；平均丰度为0.19×10⁴个/m³；类群多样性指数为1.44，均匀度指数为0.40。秋季浮游植物和浮游动物的类群数均为11。浮游植物群落的优势类群为角毛藻属(Chaetoceros)，根管藻属(Rhizosolenia)，圆筛藻属(Coscinodiscus)，海线藻属(Thalassionema)，角藻属(Ceratium)和夜光藻属(Noctiluca)。浮游动物群落的优势类群为桡足类(Copepoda)，腹足类(Gastropod)，毛颚类(Chaetognatha)，枝角类(Cladocera)，卵(Egg)，磷虾(Euphausiacea)和有孔虫(Foraminiferida)。浮游植物的平均丰度为0.39×10⁴个/m³；类群多样性指数和均匀度指数分别为2.15，0.83。浮游动物的平均丰度为0.05×10⁴个/m³；类群多样性指数和均匀度指数分别为1.89和0.57。两个季节浮游植物丰度分布的高值区均出现在有珠江口冲淡水的站位；秋季浮游动物丰度高值区的分布范围明显小于夏季。南海北部陆坡区200m以浅水层浮游生物标准化粒径谱的平均斜率为：夏季：‒0.93 (–1.09 ~ –0.61)，秋季：–0.69(–0.76 ~ –0.50)；各水层浮游生物标准化粒径谱斜率范围为：夏季：‒1.03 ~ ‒0.20，秋季：‒1.38 ~ ‒0.38。夏季浮游生物的种类和生物量均高于秋季，表现在浮游生物标准化粒径谱上是斜率比秋季陡，小粒径级浮游生物所占比重比大粒径级浮游生物大，生态转换效率低。通过浮游生物标准化粒径谱观察到，夏秋季节，在0~600m水层有浮游动物的昼夜垂直移动现象。夏季和秋季昼夜浮游生物标准化粒径谱模式相似，白天浮游生物标准化粒径谱的斜率比夜晚缓，大粒径级浮游生物比小粒径级浮游生物所占比重大。随着海域的位置离岸越来越远，浮游生物标准化粒径谱的斜率更缓，稳定性更强。随着水深的增加，大粒径级浮游生物所占比重越来越大，粒径谱的斜率有变缓的趋势。与其他热带、亚热带海域相比，南海北部陆坡区浮游动物群落中大粒径级浮游动物所占比重较大，其浮游动物标准化粒径谱斜率处于较高(陡)水平，生态转换效率处于中等水平。夏季南海北部陆坡区200m以浅水层浮游动物标准化粒径谱的斜率与近岸海域的调查结果一致，而秋季的斜率与大洋的稳定环境中的浮游动物标准化粒径谱斜率相近。浮游生物标准化粒径谱的斜率与温度有明显的负相关关系(r = –0.5065, P< 0.0001)，与盐度和叶绿素a没有相关性。在初级生产力高的海域，浮游生物标准化粒径谱的斜率比低初级生产力区域的斜率缓，生态转换效率更高。本次研究结果表明，标准化粒径谱为南海北部陆坡区浮游生物群落结构和能量流动的研究提供了有效手段，反映了夏秋季节浮游生物的分布模式，通过浮游生物标准化粒径谱参数，揭示了浮游动物的垂直移动现象和在食物网中的捕食关系，为揭示南海北部陆坡浮游生物群落分布与功能提供了重要依据。; The South China Sea is characterized by low surface nutrient concentrations and low phytoplankton biomass. Despite the oligotrophic environment, the northern continental slope area of the South China Sea possesses a highly intensive mesopelagic fish resource. Plankton provides food for mesopelagic fish. It is of interest how the plankton community structure and energy flux were. Body size is a well-established key plankton index. It can reflect physiological and ecological processes such as metabolic processes and predator-prey relationships. Size-based normalized biomass size spectra (NBSS) are attracting more and more attention as an important alternative means for the study of plankton community characteristics. The slopes of NBSS can reveal community structure and ecological conversion efficiency. The study of NBSS in China and the application of NBSS in continental slope area were little documented. Here NBSS was used to study plankton community structure and energy flow of northern continental slope area of the South China Sea. In this study, macro-, meso- and micro-plankton net and multi-net were used to sample plankton to construct plankton normalized biomass size spectra above 200m depth and stratified water plankton normalized biomass size spectra. The seasonal and diel variability, horizontal and vertical variability of NBSS were revealed, the differences of zooplankton community energy flux among tropical and subtropical seas were compared, and the relationship between NBSS slopes and environmental factors was analyzed. The results are as followed: In summer, there were 39 phytoplankton groups in phytoplankton community. The dominant groups were Chaetoceros, Rhizosolenia, Synedra, Thalassionema, Navicula and Oscillatoria. The average phytoplankton abundance was 3.74×10⁴cells/m³. The Shannon-Wiener index and Evenness index was 2.87and0.70, respectively. There were 16 zooplankton groups in zooplankton community, and the dominant groups were Copepoda, Tunicate, Gastropod and Amphipoda. The average zooplankton abundance was 0.19×10⁴cells/m³. The Shannon-Wiener index and Evenness index was 1.44and0.40, respectively. In autumn, there were 11 phytoplankton groups and 11 zooplankton groups. The dominant groups in phytoplankton community were Chaetoceros, Rhizosolenia, Coscinodiscus, Thalassionema, Ceratium and Noctiluca. And dominant groups in zooplankton community were Copepoda, Gastropod, Chaetognatha, Cladocera, Egg, Euphausiacea and Foraminiferida. The average abundance of phytoplankton and zooplankton was 0.39×10⁴cells/m³ and 0.05×10⁴cells/m³, respectively. And the Shannon-Wiener index and Evenness index in phytoplankton and zooplankton communities were 2.15and0.83, 1.89 and 0.57, respectively. High phytoplankton abundance was found near Pearl River Estuary stations, while there was no regularity of high zooplankton abundance. The plankton community average NBSS slopes above 200m water were ‒0.93 (–1.09 ~ –0.61) in summer and –0.69(–0.76 ~ –0.50) in autumn, respectively. The NBSS slope range of stratified water zooplankton were ‒1.03 ~ ‒0.20 in summer and ‒1.38 ~ ‒0.38 in autumn. Compared with autumn, there were more plankton groups, higher biomass, steeper NBSS slopes, a lower proportion of large organisms, and a lower ecological conversion efficiency from small to large plankton in summer. The diel vertical migration of zooplankton was observed from diel NBSS slopes in summer and autumn. Zooplankton vertical migration could be found at about 0~600 m. The diel NBSS pattern of plankton community was similar in summer and autumn. In daytime, the NBSS slope was flatter, proportion of large organisms was higher. Slopes from inshore to offshore stations tended to be more stable and flatter. And there was a tendency for less negative slopes and higher proportion of larger plankton with increasing depth. Compared with other tropical and subtropical seas, there was higher proportion of large zooplankton, steeper NBSS slopes in the northern continental slope area of the South China Sea. The ecological conversion efficiency was at a middle level among tropical and subtropical seas. The NBSS slope in the northern continental slope area of the South China Sea in summer was similar to the NBSS slopes of coastal regions, such as Brazilian Continental Shelf Coastal stations and the neighboring waters of Japan, while the NBSS slope in autumn was similar to the NBSS slopes of Oceanic stations, Brazilian Continental Shelf Oceanic stations and Western Pacific. There was a significant negative correlation between NBSS slopes and temperature (r = –0.5065, P< 0.0001), and no correlation was found between NBSS slopes with salinity and chlorophyll a. NBSS slopes in high primary productivity area were flatter than those in low primary productivity area, and the ecological conversion efficiency was higher in high primary productivity area. This study showed that NBSS provides an effective approach to the study of plankton community structure and energy flow of the northern continental slope area of the South China Sea. Form the NBSS, the seasonal distribution pattern was revealed, the zooplankton diel vertical migration and the predation relationship were well described. This study provides more data to reveal the distribution and function of plankton community in northern slope of the South China Sea.
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/112516
专题	胶州湾海洋生态系统国家野外研究站
作者单位	1.中国科学院海洋研究所胶州湾海洋生态系统国家野外研究站 2.中国科学院大学
推荐引用方式 GB/T 7714	张文静. 南海北部陆坡夏秋季浮游生物群落标准化粒径谱研究[D]. 北京. 中国科学院大学,2016.

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