景观水体浮游藻类变化及与水质因子关系分析

浮游藻类在不同的水质中有着不同的群落组成结构及分布特点,因此相关研究对于水质监测及水环境保护有着重要的指导意义。该研究以无锡长广溪湿地公园内河段的较清洁景观水体为研究对象,设立了10个样点,调查了2009年9月至2010年5月底秋冬春浮游藻类的时空变化情况,并研究分析了多种水质及岸带因子与浮游藻类相关指数变化的关系。研究结果表明:(1)长广溪湿地公园河段浮游藻类的群落组成结构及丰度具有明显的季节变化。秋季以蓝藻为主要优势种,丰度较高,平均值为4.7×106个/L;冬季的优势种以耐寒的硅藻及甲藻为主,丰度较低,最低值出现在1月,平均值为2.7×106个/L;春季以硅藻门为主,其中丰度最高值出现在5月份,平均值为3.4×106个/L。(2)水中的氮营养盐对浮游藻类的群落特征有重要影响,氮含量为影响浮游藻类群落的主要因子。高锰酸盐指数(OC)、补偿电导率及温度对浮游藻类群落也产生一定的影响。(3)水中不同水生植物的组合及河岸带类型对浮游藻类也有影响,有水生植物的样点水质较好,藻类较少;水中无水生植物的样点水质较差,藻类较多。河岸带植被较多的样点水质较好,浮游藻类较少;人工硬质岸带样点的水质差,浮游藻类较多。总之,长广溪湿地公园河段中浮游藻类的时空变化显著。

Spatial-temporal Variation of Phytoplankton in Clean Landscape Water in Southeast China from Autumn to Spring and Analysis of the Related Factors

Phytoplankton generally show different community structures and distribution features in the water bodies with different qualities.Therefore,their related researches have significant guiding roles on monitoring water quality and protecting water environment.This research focused on the clean landscape water body in Changguangxi Wetland Park of Wuxi.Ten locations along the lake bank were setup as sampling sites.Temporal and spatial variations of phytoplankton from September 2009 to May 2010 were surveyed and analyzed.Relationships between several water-quality indices,lake-bank factors and phytoplankton diversity indices were also analyzed.The results indicated that the community and abundance of phytoplankton in Changguangxi Wetland Park showed an obvious seasonal variation.In autumn,the blue-green algae species were dominant with high abundance,while in winter and the following spring seasons plankton diatom were dominant with the lowest abundance in January and the highest in May.Nitrogen had the strongest influence on phytoplankton and was therefore judged as the major factor.OC,Spcond and temperature had also created significant influence on phytoplankton.Aquatic plants and types of lake bank can influence phytoplankton too.With aquatic plants and vegetated banks,the water quality was good and had less phytoplankton,while it is the reversed situation with the artificially harden bank and no aquatic plants.In brief,phytoplankton in Changguangxi Wetland Park showed a significant spatial-temporal changing pattern.