东洞庭湖浮游藻类优势种群对主要水环境因子的生态适应性

【目的】研究东洞庭湖浮游藻类优势种群对主要水环境因子的生态适应性,为东洞庭湖水生态系统保护、健康评估及生物监测提供科学依据。【方法】根据物种综合数量指标(重要值IV)筛选优势种表征浮游藻类群落结构,通过因子分析法(Factor analysis)从18项水质参数中提取出主要水环境因子,运用冗余分析(Redundancy analysis,RDA)研究优势种群与主要水环境因子的关系。【结果】从优势种与环境因子的关系来看,水温与溶解氧是影响尖针杆藻(Synedra acusvar)的主要因子;变异直链藻(Melosira varians)、凸出舟形藻(Mavicula prptracta)是水体有机污染的良好指示种;草鞋形波缘藻(Cymatopleura solea)喜高浓度的氨氮;细小平裂藻(Merismopedia tenuissima)对阴离子表面活性剂敏感,而双头辐节藻(Stauroneis anceps)对阴离子表面活性剂表现出高耐受性;肘状针杆藻(Synedra ulna)对环境条件的要求较其它藻类有一定的特殊性;大多数浮游藻类喜弱碱性的水体环境。相较于以往研究,电导率并不是影响东洞庭湖藻类群落结构的主要水环境因子。【结论】东洞庭湖不同的浮游藻类优势种群对环境因子有其特定的生态适应性。

Ecological Suitability of Phytoplankton Dominant Species to Key Water Environmental Factors in East Dongting Lake

Objective] This research focused on the ecological suitability of phytoplankton dominant species to key water environmental factors.Methods] According to the importance value (IV), which covers the density, biomass and frequency, dominant species were screened to characterize phytoplankton community structure.Key water environmental parameters were screened from 18 water environmental parameters by factor analysis.Redundancy analysis (RDA)was applied to analyze the relationship between the dominant species and key water en-vironmental factors.Results] The main features of the relationship between dominant species and water environmental factors were as follows:Water temperature (WT)and dissolved oxygen (DO)were the key factors influencing Synedra acusvar.Melosira varians and Mavicula prptracta may serve as nice indicators of organic pollution.Cymatopleura solea was fit for high concentration of ammonia nitrogen (NH₃-N).Merismopedia tenuissima was sensitive to anionic surface active agents (a-SAA), however, Stauroneis anceps showed hig her tolerance to this factor.Synedra ulna was more sp ecial in the needs of environmental conditions compared with other phytoplankton.Most dominant species favored slight alkalinity.Though usually being an important influence factor for phytoplankton community structure the cenduclivity was not a dominant influencer on the phytoplankton community structure in East Dongting Lake.Conclusion] Different phytoplankton dominant species showed their specific ecological suitability to the environmental factors in East Dongting Lake.