嘉陵江四川段藻类植物群落结构及水质评价

为了揭示嘉陵江四川段藻类植物的群落结构特征和水质现状,分别于枯水期(1月)和丰水期(9月)沿江段至上而下分析了12个样点藻类群落的种类组成、Shannon多样性指数（H′）、Pielou均匀度指数（E）和Margalef丰富度指数（d).结果表明: 嘉陵江四川段共采集到藻类植物8门42科95属171种(包括变种),其中硅藻、绿藻和蓝藻为各样点的优势类群.整个江段枯水期藻类植物的平均细胞密度为14.71×10⁴ ind·L^-1,金溪和红岩子样点的密度最高,分别为28.33×10⁴和25.40×10⁴ ind·L^-1;群落中以硅藻的物种数量最为丰富.丰水期藻类植物的平均细胞密度为10.78×10⁴ ind·L^-1,以青居样点的密度最低,仅3.31×10⁴ind·L^-1,绿藻和蓝藻物种数量有所增加.整个江段12个样点枯水期和丰水期的平均d、平均H′和平均E分别为2.35、1.60、0.31和2.57、2.09和0.39.嘉陵江四川段的藻类植物群落结构、细胞密度、多样性指数和均匀度指数的时空分布格局差异显著.水质整体为中污染型,其中金溪和沙溪样点为寡污型或β中污型,水质较好;苍溪、红岩子、新政和青居样点水质较差,属α中-污型.

Community structure of phycophyta and evaluation of water quality in Sichuan section of Jialing River

In order to understand the characteristics of the phycophyta community structure and water quality in Sichuan section of Jialing River,water samples were collected from 12 sites along the section in dry season(January) and rainy season(September),with the phycophyta species composition,Shannon diversity index(H′),Pielou evenness index(E),and Margalef richness index(d) analyzed.A total of 171 phycophyta species(including variety) were collected,belonging to 8 phyla,42 families,and 95 genera,among which,Bacillariophyta,Chlorophyta,and Cyanophyta were the dominant groups.In dry season,the mean cell density of the phycophyta was 14.71×104 ind·L-1,being the highest at sites JX(28.33.4×104 ind·L-1) and HYZ(25.40×104 ind·L-1),and diatom species had a higher richness than the others.In rainy season,the mean cell density was only 10.78×104 ind·L-1,being the lowest(3.31×104 ind·L-1) at site QJ,and the species richness of chlorophyta and cyanobateria had somewhat increase.In the whole section,the mean d,H′,and E of the phycophyta were 2.35,1.60,and 0.31 in dry season,and 2.57,2.09,and 0.39 in rainy season,respectively.Our results indicated that there were significant differences in the spatiotemporal distribution patterns of the community structure,cell density,diversity index,and evenness index of phycophyta in Sichuan section of Jialing River.The water quality of this section was overall belonged to mesosaprobic,being better at sites JX and SX(belonged to oligosaprobic or β-mesosaprobic),but worse at sites CX,HYZ,XZ,and QJ(belonged to α-mesosaprobic).