嫩江下游浮游植物群落结构及其影响因子

2011年春季(5月)和夏季(7月),系统调查研究了嫩江下游对浮游植物结构群落组成、丰度的分布特征及与环境因子的关系。10个采样点中共鉴定出浮游植物7门101种及变种,春季和夏季的优势种以硅藻门为主:变绿脆杆藻、尖针杆藻、梅尼小环藻、短线脆杆藻、肘状针杆藻。不同季节各采样点浮游植物生物量在0.03~3.19 mg/L之间,丰度变幅在(0.60~32.40)×105ind./L之间。Shannon-Wiener多样性指数(H')在2.00~3.94之间,Pielou均匀度指数(J')的在0.46~0.98之间,Margalef丰富度指数(d)在1.72~4.89之间。典范对应分析(CCA)表明,水体温度是影响该水域浮游植物分布格局的重要因子,电导率和总磷浓度也对浮游植物的分布有较大的影响。CCA排序图较好显示了浮游植物物种分布和环境因子之间的关系。

Community Structure of Phytoplanktons in the Downstream of Nenjiang River and Related Affecting Factors

An investigation was conducted on the phytoplankton＇ s community composition,abundance,and their relations with environmental factors in the downstream of Nenjiang River in spring（ May） and autumn（ July）,2011. A total of 101 phytoplankton species were identified,belonging to 7phyla. Dominant species are completely from Bacillariophyta in spring and autumn. they are Fragilaria virescens、Synedra acus、Cyclotella meneghiniana、Fragilaria brevistriata、Synedra ulna and so on.The phytoplankton＇s biomass of different sampling sites were from 0. 03 mg /L to 3. 19 mg /L,and abundance at 0. 60 × 10^5 to 32. 40 × 10^5 ind /L in different seasons. Shannon-Wiener diversity index from 2. 00 to 3. 94,Pielou＇s index from 0. 46 to 0. 98,and Margalef＇s index from 1. 72 to 4. 89. Canonical correspondence analysis（ CCA） showed that water temperature was the most important factor affecting the phytoplankton＇ s community structure,and total phosphorous concentration also playedimportant role for the community structure. The CCA ordination plots could well display the phytoplankton＇s community structure and its relationships with environmental factors.