苏州工业园区湖泊后生浮游动物群落结构及影响因子

苏州工业园区地处长江流域下游，随着城市化进程的不断推进，园区水生态系统结构与功能的稳定面临严峻考验。浮游动物作为水生态系统的重要组成部分，探究其群落结构的形成机制对生物多样性保护及生态系统健康发展具有重要意义。为深入了解苏州工业园区五个主要湖泊后生浮游动物群落结构的动态变化及影响因子，于2018年7月至2019年6月进行4次调查。研究共检出后生浮游动物112种（轮虫65种、枝角类29种、桡足类18种），其中优势种12种（轮虫10种、枝角类和桡足类各1种）。Jaccard相似性分析表明，湖泊间后生浮游动物物种组成整体处于中等相似水平。后生浮游动物密度呈现出显著的季节和湖泊差异，而生物量、Shannon-Wiener多样性指数、Pielou均匀度指数以及Margalef丰富度指数仅存在显著的季节差异。聚类分析结果表明，夏季和秋季后生浮游动物群落结构最为相似。RDA分析表明，水温、溶解氧和pH是影响园区湖泊后生浮游动物群落结构的主要环境因子。Pearson相关性分析表明，湖泊面积与后生浮游动物群落结构无显著相关关系，样点近岸距离与生物量具有显著的正相关关系。基于水质评价标准和物种多样性指数可知，园区湖泊水质整体处于轻-中度污染水平。研究表明苏州工业园区五大湖泊后生浮游动物群落结构表现出同质化趋势；季节变化、环境因子以及样点近岸距离是调控群落结构形成的主要因素。

Characteristics and influencing factors of metazoan zooplankton community structure in lakes of Suzhou Industrial Park

Suzhou Industrial Park is located in the lower reaches of the Yangtze River Basin. With the continuous progress of urbanization, the stability of structure and function of the aquatic ecosystem in the Park is facing severe challenges. Zooplankton, as an important part of the aquatic ecosystem, is of great significance for the biodiversity protection and healthy development of the ecosystem by researching the formation mechanism of its community structure. Moreover, zooplankton is very sensitive to environmental changes, and the water pollution status can be evaluated based on its community structure characteristics. To better understand the community structure and influencing factors of metazoan zooplankton in five lakes of Suzhou Industrial Park, four surveys were conducted from July 2018 to June 2019. At the same time, five physical and chemical factors of water body, lake area, and the closest distance from samples to the shore were measured. A total of 112 metazoan zooplankton species (including 65 species of Rotifera, 29 species of Cladocera, and 18 species of Copepoda) were detected in this study, in which 12 species were dominant species (including 10 species of Rotifera, 1 species of Cladocera, and 1 species of Copepoda). Jaccard similarity analysis indicated that the species compositions of metazoan zooplankton among lakes were moderately similar. The density of metazoan zooplankton showed the significant differences in different seasons and locations, while biomass, Shannon-Wiener diversity, Pielou evenness, and Margalef richness indexes only had significant differences in seasonal aspect. The results of cluster analysis suggested that the metazoan zooplankton community structure was the most similar in summer and autumn. It was revealed that temperature, dissolved oxygen, and pH were the main environmental factors affecting the community structure of metazoan zooplankton by redundancy analysis. Pearson correlation analysis indicated that there was no significant correlation between lake area and metazoan zooplankton community structure, while a significantly positive correlation between the distance from samples to the shore and metazoan zooplankton biomass was detected. Based on the water quality evaluation standard and species diversity indexes, the water quality of the lakes in the Park was at a light to moderate pollution level. Overall, the metazoan zooplankton community structure in the five lakes of Suzhou Industrial Park showed a trend of homogeneity, and the seasonal variation, environmental factors and the distance from samples to the shore were main factors regulating the formation of community structure. The results of metazoan zooplankton community structure could provide an effective reference for the restoration and development of lake water in the Park.