| 生物要素的海洋生物地球化学过程研究进展 |
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| 引用本文： | 罗延馨,宋金明.生物要素的海洋生物地球化学过程研究进展[J].海洋科学集刊,1999(41):65-78. |
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| 作者姓名： | 罗延馨 宋金明 |
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| 作者单位： | 中国科学院海洋研究所 |
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| 基金项目： | 中国科学院海洋研究所调查研究报告第3321号;国家自然科学基金资助项目,49776300号。 |
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| 摘 要： | 新学科的诞生是社会发展的需要,人类社会发展到今天,由于人类面临的资源与环境问题,使占全球面积71%的海洋成为21世纪开发的重点领域。然而,各成体系的海洋化学、海洋生物、海洋地质和海洋水文,已难以适应认识和解决当前面临的全球变化问题的需要。80年代初,随着国际地圈生物圈计划(IGBP)、全球海洋通量联合研究(JGOFS)、全球海洋生态系统动力学(GLOBEC)、全球海洋真光层研究(GOEZS)、海岸带陆海相互作用(LOICZ)等重大国际合作计划的兴起,处于这些学科交叉点上的海洋生物地球化学这新的分支学科应运而生,至90年代,这一边缘交又研究方向已成为海洋学研究的前沿领域。
我国的海洋生物地球化学研究虽起步较晚,但已取得飞速发展。至今,已开展实施了渤海生态系统动力学、东海海洋通量、台湾海峡生源要素生物地球化学过程、南海碳通量、南沙群岛珊瑚礁生态系物质循环等一系列重点项目的研究,强有力地推动了这一边缘交叉学科的发展。
海洋生物地球化学是利用化学、地质、生物、物理的观点综合研究海洋中物质循环的过程与规律,突出的特点是研究生物作用下的地球化学过程,研究的主要对象是生源要素(C,N,P,S,Si等)及与生物过程有关的其他元素。
本文从真光层内生源要素的循环、海水中颗粒物的生物地球化学过程、沉积物-海水界面过程中的生源要素,以及微型生物在生源要素的海洋生物地球化学循环中的作用等方面阐述了生源要素的海洋生物地球化学过程研究进展,以期推进我国该领域研究水平的提高。
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| 关 键 词： | 生物要素、海洋生物地球化学 |
| 收稿时间： | 1997/12/1 0:00:00 |
PROGRESS IN STUDIES ON MARINE BIO GEOCHEMICAL PROCESS OF BIOGENIC ELEMENTS |
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| Luo Yanxin,Song Jinming.PROGRESS IN STUDIES ON MARINE BIO GEOCHEMICAL PROCESS OF BIOGENIC ELEMENTS[J].Studia Marina Sinica,1999(41):65-78. |
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| Authors: | Luo Yanxin Song Jinming |
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| Institution: | Institute of Oceanology, Chinese Academy of Sciences |
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| Abstract: | This paper reviews the progress in the study of marine biogeochemical processes of biogenic elements (C, N, P, S, Si) and consists of four parts:
1. The cycling of biogenic elements in the euphotic zone
The air-sea exchange process of biogenic elements is an important link in the euphotic zone cycle. The interface behaviors of some trace gases which can affect global climate and the possible influencing factors (mainly referring to biological processes) are discussed. The exchange of carbon between atmosphere and ocean depends on the CO2 partial pressure (PCO2) difference; DMS is mainly released from the sea. PCO2 and DMS are controlled by biogeochemical processes to some extent. These results are useful to understanding systematically the importance of the ocean in global climate change.
The euphotic zone is the most active region in the marine biogeochemical processes of biogenic elements. Phytoplanktons transform DIC into DOC by photosynthesis, absorbing nutrients (N, P, Si) in certain proportion. On the other hand, they are generally eaten by mesozooplankton and macrozooplankton, and are then excreted as sinking fecal pellets, some of them are decomposed and disolved again, others off the euphotic zone, including regenerated nutrients in mid-or deep-ocean, may be brought to upper water by upwelling. The processes of cycling and regeneration of biogenic elements in the euphotic sea are very complicated.
2. Marine biogeochemical process of particulates
Important information concerning the biology, chemistry and geology of particulates can be obtained by studying their component variations, vertical fluxes and transport mechanism.
By discussing the component variations with space and seasons, the particulates origin and function in transporting and storaging biogenic elements are reviewed. There are two main factors cited to explain the changes of vertical fluxes-biology and physics, such as the contribution of diatom bloom to exportable organic matter from the upper water, the influences of wave, lateral transport, El Nino/Southern Oscillation. The vertical transport mechanism of particulate matter tends to be dominated by the biogeochemical cycle.
3. The behaviour of biogenic elements near the sediment-water interface
The exchange amount across the sediment-water interface is large. The fluxes from sediment to water in global oceans, Nansha lagoons, Xiamen western sea, etc. and the carbon fluxes to the sea floor in the Scheldt River estuary and Chesapeake Bay are summarized. The exchange processes keeping the interface ecological system balance and the behavior differences reflecting the different environmental characteristics are discussed on the basis of thermodynamics and kinetics theory, e.g. redox balance, percipitation-dissolution system, diagenetic process. In addition, the biological process affecting interface behaviours, such as phytoplankton and benthos bioturbation which strengthens the exchange between the water and sediment, are mentioned.
4. Role of small organisms in the marine biogeochemical cycle of biogenic elements
Recently, small organisms (mainly referring to phytoplankton and bacteria), have been paid much more attention. Due to the finding of the microbial loop, the contribution of bacteria producers appear to be much greater than thought before. First, microorganisms are important storers of POM, especially in the eutrophic zone. Second, they can utilize biogenic elements. As decomposers, their contributions lie in returning the "lost" energy to the food chain. This is one of the key links in the biological process which controls elements cycling. |
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