生态调控后贵州花溪水库浮游植物群落结构的变化特征及影响因素

为了解生态调控后花溪水库浮游植物功能群变化特征与环境因子的关系，基于浮游植物功能群、NMDS（非度量多维尺度分析）、RDA（冗余分析）、Pearson相关性分析方法，于2017年3月-2018年3月逐月对浮游植物群落结构与水环境指标进行采样分析.结果表明:①生态调控前，花溪水库共鉴定浮游植物4门18种，共归类出10个功能群，且功能群H1占绝对优势，其代表藻种为水华束丝藻（Aphanizomenon flosaquae）；生态调控后，共鉴定浮游植物6门66种，共归类出20个功能群，主要优势功能群为B/Lo，其代表藻种为小环藻（Cyclotella sp.）和多甲藻（Peridinium sp.）.②生态调控后，花溪水库优势功能群结构发生了变化，其变化特征为B/Lo（春季）→D/B/Lo/X2/N/P（夏季）→D/B/Lo/N（秋季）→D/MP/B/Lo/W1/W2（冬季）.功能群B的生物量在春季达到峰值（3 056.3 μg/L），与其对低营养环境有良好的耐受性有关；功能群Lo的生物量在秋季达到峰值（2 900.9 μg/L），与组成功能群Lo的甲藻特性有关.③RDA结果表明，生态调控前影响浮游植物生长的环境因子为SD（透明度）、ρ（DIN）（DIN为无机氮）；生态调控后影响浮游植物生长的环境因子为WT（水温）、ρ（DO）、ρ（DIN）.研究显示，生态调控后花溪水库功能群结构发生了明显变化，影响功能群变化的主要环境因子为WT和ρ（DO）. 

Variation Characteristics and Influencing Factors of the Structure of a Phytoplankton Community After an Ecological Regulation in Huaxi Reservoir, Guizhou Province

In order to understand the relationship between variation characteristics and the environmental factors on the phytoplankton functional groups after the ecological regulation in Huaxi Reservoir, the structure of the phytoplankton community and the water chemical variables were analyzed from March 2017 to March 2018 based on the phytoplankton functional group, nonmetric multidimensional scale analysis (NMDS), redundancy analysis (RDA) and Pearson linear correlation analysis. The results showed that:(1) Before the ecological regulation in Huaxi Reservoir, 18 species of phytoplankton belonging to 4 phyla were identified, with the classification into 10 functional groups, among which the dominant group was H1, and the representative species was Aphanizomenon flosaquae. After the ecological regulation, 66 species of phytoplankton within 6 phyla were identified, and 20 functional groups were divided with B/Lo as the dominant functional group, which was mainly represented by Cyclotella sp. and Peridinium sp. (2) After the ecological regulation, the structure of dominant functional groups changed, which was characterized by B/Lo (spring)→D/B/Lo/X2/N/P (summer)→D/B/Lo/N (autumn)→D/MP/B/Lo/W1/W2 (winter). The biomass of the dominant functional group B peaked in spring (3056.3 μg/L), which was related to its good tolerance to low nutritional variability. Meanwhile, the biomass of the dominant functional group Lo peaked in autumn (2900.9 μg/L), which was attributed to the property of dinoflagellates with the functional group of Lo. (3) The redundancy analysis (RDA) further revealed that secchi disk depth (SD) and dissolved inorganic nitrogen ρ(DIN) were the two primary factors influencing phytoplankton growth before ecological regulation. Besides, water temperature (WT), ρ(DO) and ρ(DIN) were the primary environmental factors affecting phytoplankton community after ecological regulation. Overall, this study shows that the structure of functional groups changed obviously after ecological regulation in Huaxi Reservoir, which was mainly affected by environmental factors of WT and ρ(DO).