红树林生态系统微生物驱动的氮素循环过程研究进展

Microbially-driven nitrogen cycle in mangrove ecosystems

摘要:

微生物驱动的氮循环过程在红树林生态系统物质循环、净化外来污染物、维持生态系统平衡等方面起重要作用。相较于其他自然生态系统，因红树林处于沿海陆地交界地带，其氮循环过程及其相关微生物的种类丰富，受交错复杂的环境因素影响与调控。本文梳理了红树林土壤性质及特性，综述了红树林生态系统中由微生物驱动的固氮、氮素矿化、硝化、厌氧氨氧化、反硝化、异化硝酸盐还原为铵等主要的氮循环过程，并讨论了氮循环与其他循环的耦合过程。最后讨论pH、盐度、季节、螃蟹活动、红树林树种等环境因素对氮循环过程及其相关微生物丰度、多样性的影响。本综述以期为红树林湿地生态系统的保护和修复提供理论参考。

关键词:红树林;微生物;氮素循环;耦合过程;环境因素

Abstract:

Nitrogen cycle driven by microorganisms plays an important role in the material cycle, purification of external pollutants, and maintenance of ecosystem balance in the mangrove ecosystems. Compared with other natural ecosystems, mangrove which inhabits in coastal saline or brackish water, boasts multiple nitrogen cycle processes and diverse related microorganisms which are affected and regulated by complex environmental factors. This study summarized the properties and characteristics of mangrove soil and reviewed the main nitrogen cycle processes driven by microorganisms in mangrove ecosystems, such as nitrogen fixation, nitrogen mineralization, nitrification, anaerobic ammonia oxidation, denitrification and dissimilatory nitrate reduction to ammonium. In addition, we discussed the coupling process of nitrogen cycle and other cycles. Finally, we analyzed the influence of environmental factors such as pH, salinity, season, crab activity, and mangrove species on the nitrogen cycle and the related microbial abundance and diversity in the mangrove ecosystems. This review is expected to serve as a reference for the protection and restoration of mangrove ecosystems.

Key words:mangrove;microorganisms;nitrogen cycle;coupling process;environmental factors