【作者】 付翔；

【导师】 韩博平；

【作者基本信息】 中国科学院研究生院（海洋研究所） ， 海洋生物学， 2007， 博士

【摘要】 本文的研究内容是初级生产力模型计算方法以及活体叶绿素荧光测量方法在我国近海浮游植物光合作用研究中的应用。论文对在我国近海实测的1321组叶绿素垂直分布数据以及84组初级生产力数据进行了非线性拟合分析,得出了描述叶绿素和初级生产力垂直变化规律的相应参数。结合光合参数——初始斜率α的平面分布将我国近海分为9个光合作用特征相对独立的分区。以光强和遥感叶绿素为输入变量,以各分区实测参数的平均值为模型参数,首次建立了分海区的时间-深度积分初级生产力计算模型。对拟合参数的分析表明:我国近海深水叶绿素峰（DCM）在夏季最明显而在冬季则不明显,这与夏季温跃层的形成和冬季温跃层消失的规律相符合。最大光合速率参数主要受温度和营养盐状况的影响,但整体而言各个季节的变化不大。光合作用初始斜率参数主要受浮游植物光照条件和光照历史的影响,从春季到冬季持续增加,基本与光照强度的变化刚好相反。光抑制参数反映着浮游植物对高光强伤害的敏感性,它在夏、秋季较低而在冬季较高。模型计算结果表明我国近海初级生产力规模约为6.4±1.0×108tC/a。总体来说我国近海海域初级生产力北方高于南方,西部高于东部。北方初级生产力高峰期大都出现在夏季而南方出现在冬季,中部则高峰期出现在春秋两季,与温跃层出现和消失的规律有一定的相关性。与由实测生产力推算的初级生产力相比,本模型的计算结果较高,误差产生的原因包括二类水体遥感叶绿素浓度偏高、地形因素等。与VGPM相比较,本模型的计算结果更接近于实测结果。模型中云覆盖度参数的变化可能引起计算结果约25%的变化,当取云覆盖度参数为0.5时的计算结果与用实际天气状况数据的计算结果较为接近。制作了基于分区模型的水柱初级生产力计算软件,可在仅测量叶绿素浓度的情况下进行水柱初级生产力的计算。模型准确度的进一步提高的途径主要包括实测参数数量的增加以及遥感叶绿素浓度准确性的提高。与初级生产力相比,活体叶绿素荧光测量可以更快速、简便地跟踪浮游植物光合作用动态。本研究首次将活体叶绿素荧光测量方法应用于野外浮游植物光合作用状态研究。通过暗驰豫实验,建立了使用OS5-AFM藻类荧光仪现场测定活体叶绿素荧光参数——F_v/F_m（光化学效率）的操作方法,并对胶州湾海域浮游植物光化学效率进行了高时空分辨率的调查,对相关因素进行了分析,并尝试通过F_v/F_m进行初级生产力计算。结果表明,胶州湾海域表层F_v/F_m值的全年平均值约0.37,处于中等偏低水平。F_v/F_m值在秋季最高而春季最低,其平面分布在夏季较均匀而在春季则有较大的区域差异。湾东部F_v/F_m值变化幅度较大,一年中有4个高峰期;而湾西部F_v/F_m值变化幅度较小,一年中有3个高峰期。光合作用最活跃的海区随季节更替而变化,其年变化模式可能具有一定的重复性。不同深度上F_v/F_m值的海区平均值没有显著差异,但底层F_v/F_m值的空间差异较小。通过对营养盐和F_v/F_m值时间变化的分析,首次发现了自然水体中F_v/F_m值变化对氮盐浓度变化响应的滞后效应,在不同的站点,影响F_v/F_m值的氮盐种类有所不同,湾西部海域与NH₄⁺相关性较高而湾东部海域与NO3-的相关性较高,P、Si等则与F_v/F_m值基本无相关性。滞后期的长度并不稳定,1旬和2旬的滞后现象都可观察到。F_v/F_m值变化率与氮盐浓度变化率之间的相关性高于F_v/F_m值与氮盐浓度之间的相关性。这表明即使在胶州湾这样无机氮浓度很高、浮游植物生长基本不受氮源限制的水体,氮源浓度的变化仍然影响着浮游植物的光合作用状态。初步建立了由F_v/F_m测量结果计算初级生产力的方法。模型的计算结果与文献资料中胶州湾水域初级生产力的时空分布趋势基本一致,但在数量上明显低于传统估算的结果。获得更多同步测量的初级生产力和F_v/F_m值数据可逐渐改善这一方法计算结果的准确性,并可籍次方法更快更方便地进行初级生产力的测算。更多还原

【Abstract】 In this paper, modeling of primary production and in vivo chlorophyll fluorescence measurement are introduced into the study of the photosynthesis of phytoplankton in China Sea。1321 sets of chlorophyll data and 84 sets of product data were analyzed by nonlinear estimation, and the corresponding parameters that describing the chlorophyll vertical distribution and product-light curve were generated. Reference to the spatial distribution of the photosynthesis parameter, primary slope -α, the China Sea is separated into 9 provinces with different photosynthesis feathers. A primary production model that using light intensity and remote sensed chlorophyll concentration as input was developed, using the average values of the measured parameters of each province as the local parameter of the model.Analysis of the parameters shows that: The deep chlorophyll maximum （DCM） is marked in summer while is weak in winter, matching the phenomena that the thermocline appears in summer and disappears in winter. The maximum photosynthetic rate is related to temperature and nutrients, and it varies little through seasons. The primary slope of photosynthesis is most affected but the light history. It increases from spring to winter, opposite to the variation of seasonal variation of the irradiance. The photoinhibtion parameter presents the sensitivity of the phytoplankton to high light damages. It is low in summer and autumn, and is high in winter.Calculation result shows that the annual primary production of China Sea is about 6.4×108tC. The primary production in the north area of China Sea is higher then south area, and west area is higher then east area. The primary production maximum appears in summer for the north area while it appears in winter for the south area, and it appears in spring and autumn in the middle area, probably relating to the appearance of thermocline. The primary product calculated by the model is in some degree higher than that estimated by the measured primary production data. The errors may derived from the over estimation of the chlorophyll concentration for remote sensing of the type II water, and discounting the bottom topography, etc. Compare to the result of VGPM, our model is more close to the measured data. Cloud cover may lead to 25% variance of the primary production, and it is close to the real PAR situation when the cloud cover takes the value 0.5. We produced a application software based on the model, which can calculate the primary production just by chlorophyll concentration data. The improvement of the accuracy of the model relies on acquirement of more measured primary production data and more better remote sensing chlorophyll concentration data.In vivo chlorophyll fluorescence measurement is a rapid and facility method for tracing the photosynthesis activity of phytoplankton. In this study, we introduced the in vivo chlorophyll fluorescence measurement into the field investigation of phytoplankton photosynthesis status. By the dark-relaxation experiment, we developed the procedure for in situ measurement of phytoplankton F_v/F_m （photochemical efficiency, the maximum proportion that the energy used in the primary photochemical reactions in the total light energy absorbed by the light harvesting system） -a commonly used in vivo chlorophyll fluorescence parameter, by the OS5-AFM algae fluorometer. We made a high spatial-temporal investigation of phytoplankton photochemical efficiency in Jiaozhou Bay （2003-2004）, and analyzed the relating factors. We made an attempt to calculate the primary production by F_v/F_m data.The investigation shows that, annual average of F_v/F_m for Jiaozhou Bay is about 0.37. It is highest in autumn and lowest in spring. The spatial variation of F_v/F_m is large in spring and small in summer. F_v/F_m in east part of the bay varies in a large range, and exhibit 4 peaks through the year. F_v/F_m in the west part of the bay is relatively stable, and exhibit 3 peaks through the year. The subregion of the bay that photosynthesizing most actively changed over seasons. The shifting mode is probably repetitious every year. The averages of F_v/F_m of each depth were not remarkably different, but the F_v/F_m values at bottom present a more evenly spatial distribution than that of the surface.By analyzing the dynamic of F_v/F_m and nutrients through the year, the phenomenon that the variation of F_v/F_m is lagging to the variation of inorganic nitrogen concentration in nature waters is first been discovered. In west part of the bay, F_v/F_m is more related to NH₄⁺ while in east part of the bay it is more related to NO₃^-. The lagging period may vary. The relativity between change rate of F_v/F_m and change rate of inorganic nitrogen concentration is higher than that F_v/F_m vs inorganic nitrogen concentration. It implicate that, even in waters in which inorganic nitrogen concentration is high so that the growth of phytoplankton is not limited by nitrogen supply, the variation of the concentration of nitrogen may still affect the photosynthesis activity of the phytoplankton.We tested the method to calculate the primary production by the parameters deriving from F_v/F_m and the water column primary production integral model. The result exhibit similar spatial and temporal distribution to that reported by presented literatures. But in quantity, our result is obviously lower. Acquirement of more synchronous F_v/F_m vs primary production data may improve the accuracy of the model. By this way, more rapid and convenient primary production measurement will be possible.更多还原