潮滩生态系统中生源要素氮的生物地球化学过程研究综述

ADVANCES IN THE STUDY ON NITROGEN BIOGEOCHEMISTRY IN TIDAL FLAT ECOSYSTEM

海岸带潮滩生源要素生物地球化学循环过程是国际地圈生物圈计划(IGBP)、海岸带陆海交互作用(LOICZ)研究的重要内容,也是全球变化区域响应研究中的重要组成部分。在过去的10～20年之间,潮滩生源要素氮的生物地球化学循环研究得到了长足的发展。基于此,较为全面、系统地总结和分析了有关潮滩氮营养盐的来源、潮滩氮素的物理、化学和生物迁移转化过程及氮素地球化学循环过程中底栖生物效应等一系列研究成果,并提出了今后潮滩生源要素氮的生物地球化学循环研究重点和发展趋向。

Nutrient biogeochemical cycling in the tidal flat ecosystem is not only one of the key studying contents of IGBP and LOICZ projects, but also the important component in the study of global change and region Response. Coast and tidal flat is an open and complex ecosystem. A lot of nitrogen nutrient may be directly transported into coastal zone through riverine input, penetration of groundwater, atmospheric deposition and the exchange with offshore water. Some findings showed that atmospheric inputs made the main contribution to the source of nitrogen in the coastal and tidal flat ecosystem. In addition, the decomposition of organic matter accumulated in the tidal sediment is also an important source of nitrogen. In recent years, some researchers have tried to source nitrogen by using carbon and nitrogen isotopes in organic matter in the tidal flat ecosystem. Nitrogen cycling has the important and ecological significance to primary products in the tidal flat ecosystem. Therefore, the processes of nitrogen cycling in the tidal flat ecosystem, e.g. nitrogen fixation, nitrification and denitrifciation, have well been studied in the last decades. Many references reported the effects of environmental factors and sediment physiochemical parameters on the processes of nitrogen cycling including physical, chemical and biological process of nitrogen transportation and transformation. Benthic benthos is an important component of the tidal flat ecosystem, which plays a key role in the nitrogen cycling in the tidal flat ecosystem. It has been reported that benthic benthos had the important effects on the processes of nitrogen cycling in tidal flat. In addition, the trend of the study on nitrogen biogeochemistry cycling in the tidal flat ecosystem was also expatiated in the paper.