贡湖浮游植物时空分布特征及其与环境因子的关系

为了弄清贡湖生态环境特征，基于 2013 年 3 月至 2014 年 2 月间贡湖 8 个采样点水环境状况的监测数据，运用数理统计分析手段，对浮游植物时空分布特征及其与环境因子的相关性进行了分析。贡湖总体上处于富营养化状态，而水源地附近水环境状况相对较好。蓝藻水华易发期水质透明度、悬浮物、叶绿素 a 、亚硝态氮、总氮时空分布差异显著（ANOVA ，p ＜ 0.05）。浮游植物细胞密度的空间分布差异显著（ANOVA ，p ＜ 0.05），浮游植物细胞密度的最高值出现在 2 号点，最低值出现在 5 号点。利用 Pearson 相关性分析法分析藻细胞密度与环境因子间的关系，表明藻细胞密度与总氮、总磷、高锰酸盐指数、悬浮物、叶绿素 a 呈极显著相关，与溶解氧呈极显著负相关。利用冗余度分析（redundancy analysis，RDA） 浮游植物种类组成与环境因子之间的关系，表明营养盐（总氮、总磷和氨氮）、高锰酸盐指数、水温、悬浮物、pH 是影响浮游植物组成的主要因素。贡湖水生态环境特征存在显著的空间特征异质性。浮游植物群落结构组成受到水环境特征和空间相邻性的双重影响。
The spatial-temporal characteristics of phytoplanktons and its relationship with environmental factors were studied to understand the ecological environment characteristics，using multivariate statistical analysis based on the monitoring data recorded from March 2013 to February 2014 in the Gonghu Bay. Gonghu Bay was generally in a eutrophic state; however，the nearby sampling sites were in a relative better condition. The significant spatial-temporal characteristics was observed for the transparency，suspended substance，chlorophyll a，nitrite and the total nitrogen during cyanobacteria bloom (ANOVA，p＜0.05). A comparatively high spatial heterogeneity was indicated in the phytoplankton community composition (ANOVA，p＜0.05 ). The maximum cell density was found in the 2nd sampling site，while the minimum in the 5th sampling site. Pearson correlation analysis was performed to illustrate the relationship between algae density and environmental variables. Significant positive correlations were found between algae density and the total nitrogen，total phosphorus，permanganate index，suspended substance，and chlorophyll a. But the correlations between algae density and dissolved oxygen were highly negative. Relationship between phytoplankton community composition and environmental factors were analyzed by redundancy analysis (RDA). The results indicated that nutrients (i.e.，the total nitrogen，total phosphorus and ammonia nitrogen)，permanganate index，water temperature，suspended substance，and pH made a major contribution to the composition of phytoplankton community. There was a remarkable spatial heterogeneity of ecological environmental in Gonghu Bay. The phytoplankton community composition was substantially and cooperatively affected by the environmental characteristics and adjacent sampling sites