赤水河云南境内主要支流浮游植物群落结构研究

Research on phytoplankton community structure of main tributaries of the Chishui River in Yunnan Province

为了解赤水河云南境内主要支流浮游植物群落结构及其时空动态格局,于2022年丰水期(6月)、平水期(10月)和枯水期(12月)在石坎河、妥尼河以及铜车河共设置5个采样点分析水质现状并采集浮游植物。结果显示,除石坎河外,水质总体较好(不计总氮),妥尼河和铜车河水质基本维持在Ⅱ类,部分季节甚至可达Ⅰ类水质。调查期间共采集浮游植物206种(变种),隶属于7门20目35科75属,以硅藻门种类最多,占全部浮游植物种类的63.11%。浮游植物总平均密度(31.27±18.00)×10^(4) cells/L,总平均生物为0.3133±0.2063 mg/L。基于相似性分析(ANOSIM)结果表明,浮游植物群落结构呈现显著的季节性差异(R=0.0654,P<0.05),但无明显的空间差异(R=-0.086,P>0.05)。依优势度指数(Y),调查区域浮游植物共有18种优势种类,包括硅藻门11种、绿藻门4种、蓝藻门2种和隐藻门1种。各样点浮游植物群落Shannon-Wiener多样性指数(H')介于2.46~3.61,Pielou均匀度指数(J')介于0.67~1.00,Margalef丰富度指数(D)介于2.27~3.88,单因素方差分析(One-way ANOVA)结果显示3种多样性指数无明显的季节(P>0.05)和空间(P>0.05)差异;基于多样性指数的水质评价结果表明,赤水河云南境内主要支流整体呈现β中污染至寡污染。本研究结果可以为赤水河流域水生态环境保护提供更多基础资料,同时,为其它流域开展水生态修复提供科学依据。

To understand the phytoplankton community structure and its spatio-temporal dynamic pattern in the main tributaries of the Chishui River in Yunnan Province,a total of 5 sampling sites were set up in the Shikan River,Tuoni River and Tongche River,respectively.The water quality was analyzed and the phytoplankton sampling was completed during wet season(June),normal season(October)and dry season(December)in 2022.The results showed that the water quality was generally good in the Tuoni River and the Tongche River(excluding total nitrogen),which were basically maintained in classⅡwater quality.In some seasons,the water quality can even reach ClassⅠin the Tuoni River and the Tongche River.A total of 206 species(varieties)of phytoplankton were collected during the survey,belonging to 7 phyla,20 orders,35 families and 75 genera.Diatoms accounted for 63.11%of the total phytoplankton species.The average density of phytoplankton was 31.27±18.00×10^(4) cells/L,and the average biomass was 0.3133±0.2063 mg/L.Significant seasonal differences(R=0.0654,P<0.05)of phytoplankton community structure was detected by similarity analysis(ANOSIM).However,no significant difference of phytoplankton community structure was found(ANOSIM,R=-0.086,P>0.05)among the Shikan River,the Tuoni River and the Tongche River.According to the dominance index(Y),there were 18 dominant phytoplankton species in the survey area,including 11 species of diatom,4 species of chlorophyta,2 species of cyanobacteria and 1 species of cryptophyta.Shannon-Wiener diversity index(H')ranged from 2.46 to 3.61,Pielou evenness index(J')ranged from 0.67 to 1.00,Margalef richness index(D)ranged from 2.27 to 3.88.The results of One-way ANOVA showed that there were no significant seasonal(P>0.05)and spatial(P>0.05)differences among the three diversity indexes.The results of water quality evaluation based on diversity index showed that the main tributaries of the Chishui River in Yunnan Province showedβ-medium to oligo-pollution.The results of this study can provide more basic data for aquatic ecological environment protection in the Chishui River basin,and provide scientific basis for aquatic ecological restoration in other rivers.