鄱阳湖不同水文期浮游生物群落结构特征和影响因素及水质评价

为阐明鄱阳湖不同水文期浮游生物群落结构特征及其影响因素,研究于2017年8月(丰水期)和12月(枯水期)在鄱阳湖湖区典型水域设置5个采样点进行浮游生物采样调查。研究期间共鉴定浮游植物8门75属186种,丰水期与枯水期均以硅藻门和绿藻门为主。共鉴定浮游动物4类76种,丰水期与枯水期均以原生动物和轮虫为主。方差分析显示:浮游植物密度与生物量在不同水文期之间的差异均为极显著(P<0.01),浮游动物丰水期密度高于枯水期,但无显著差异(P>0.05),浮游动物生物量(P<0.05)在不同水文期差异显著。冗余分析(RDA)显示:丰水期透明度和浮游生物呈显著负相关关系,电导率和浮游生物呈显著正相关。透明度、电导率与营养盐是影响丰水期浮游生物群落结构的主要环境因素,枯水期水温和溶解氧是驱动鄱阳湖浮游生物群落生态分布的主要环境因素。基于Shannon-Wiener(H′)、Margalef(d)和Pielou(J)等生物多样性指数的水质评价结果表明:鄱阳湖研究区域水质状态处于寡污-中污之间。研究揭示了2个水文期对通江湖泊浮游生物的影响:季节变化不改变湖泊浮游生物的物种组成及优势种,但...

COMMUNITY STRUCTURE AND THE WATER QUALITY DURING DIFFERENT HYDROLOGICAL PERIODS IN POYANG LAKE

Poyang Lake is a large Yangtze-connected lake in the middle and lower reaches of the Yangtze River and its water level fluctuates periodically with the hydrological rhythm. In order to clarify the characteristics and influencing factors of plankton community structure during different hydrological periods, the survey on plankton structure was conducted at five typical sampling sites of Poyang Lake in August (wet season) and December (dry season) of 2017. The results indicated that phytoplankton assemblage was composed of 186 species and 75 genera, belonging to 8 phylum. Bacillariophyta and Chlorophyta dominated in wet and dry seasons. Zooplankton was composed of 76 species, belonging to four taxonomic groups. Protozoa and Rotifers were dominant during wet and dry seasons. The density and biomass of phytoplankton were statistically significantly higher during wet season than those during dry season (P<0.01). The density of zooplankton in wet period was higher than that in dry water period, but there was no significant difference (P>0.05). The biomass of zooplankton (P<0.05) was significantly different in different hydrological periods. Redundancy analysis suggested that there was negative correlation between the plankton community structure and transparency. The conductivity showed a positive correlation with the plankton community structure. Transparency, conductivity and nutrient were key factors affecting the community structure of plankton during wet season, whereas water temperature and dissolved oxygen were key factors affecting the community structure of plankton during dry season. Based on the diversity indices of Shannon-wiener, Margalef and Pielou, the results showed that the water quality of Poyang Lake was at low-to-medium pollution level. Our findings revealed the impact of two hydrologic periods on the plankton of Yangtze-connected lakes. Seasonal change did not change the species composition and dominant species of plankton in Poyang Lake, but affected the abundance and diversity of plankton greatly.