珠江河口的浮游细菌生态学研究进展

Advances in ecological research of Pearl River Estuarine bacterioplankton

摘要:

河口地区是海陆交互作用的集中地带，生态环境十分脆弱敏感，物质循环机制复杂，而浮游细菌（bacterioplankton）参与的生态过程是河口生态系统物质循环的重要环节。珠江河口是独特的典型亚热带河口。近年的研究表明，浮游细菌在珠江河口生态系统物质循环中占有重要地位，其生产力和丰度受噬菌原生动物（鞭毛虫）和病毒的控制，而且其生物量与浮游植物的数量具有显著的相关性。珠江河口的优势浮游细菌类群为变型菌门（Proteobacteria）和蓝藻菌（Cyanobacteria）等，浮游细菌丰度和群落结构变化主要受到盐度、温度、营养盐水平等因素的影响。珠江河口浮游细菌与地球物质循环功能鲜有报道，而且珠江河口生态系统中有机质的浮游细菌转化机制和生态学效应更是没有深入研究。基于此，本文全面综述了珠江河口浮游细菌种类组成、分布、生物量、地球物质循环及其环境影响因素等方面的研究进展，有助于系统性地揭示近海生态系统的特征；同时，本文作者还对珠江河口浮游细菌生态学研究今后值得关注的科学问题进行了探讨。

关键词:珠江河口;浮游细菌;生态学;物质循环

Abstract:

Estuarine ecosystems are characterized by extreme variations of salinity and nutrients. In such ecosystems, mechanisms of matter cycling are highly complex. Apart from the influences of fresh and marine water, and interaction between land and ocean, bacterioplankton also plays an important role in the matter cycling in estuarine aquatic ecosystems. Studies on bacterioplankton are, therefore, considered important for the understanding of matter cycling in the subtropical estuary such as that of the Pearl River Estuary. Previous studies in Pearl River Estuary show that the most dominant bacterioplankton groups were Proteobacteria and Cyanobacteria. While the bacterial community structure and abundance were influenced by salinity, temperature and nutrient concentration, their productions and abundance were limited by virus and flagellate, and there was positive relationship between bacterial biomass and phytoplankton. However, there were no comprehensive studies about function and cycle of earth matter of bacteria in Pearl River Estuary. Knowledge gaps still exist about mechanism for transformation of organic matter driven by microorganism and the corresponding ecological significance in this region. This review covers studies on estuarine bacterioplankton species composition, distribution, biomass, matter cycling and other relative environmental factors. Additionally, this article provides a future framework for Pearl River Estuary aquatic ecological system.

Key words:Pearl River Estuary;bacterioplankton;ecology;matter cycling