【作者】 盛金萍；

【导师】 郭劲松；

【作者基本信息】 重庆大学 ， 市政工程， 2010， 硕士

【摘要】 三峡工程举世瞩目,是跨世纪的特大型水利枢纽工程,具有航运、防洪和发电等多重功能,在给我国带来巨大经济效益的同时,也将极大改变长江三峡区域的生态环境,并将对长江流域的生态环境产生深远影响。本研究以三峡水库较具代表性的小江流域回水区段对其富营养化过程与水华现象展开为期1年的野外定位跟踪观测,分析藻类集群结构的季节变化特征,并引入目前藻类功能分组的研究成果,揭示小江回水区优势藻与藻类功能组的季节演替特征,研究优势藻、藻类功能组同环境要素间的相互关系,为建立藻类集群演替的生态模型与三峡水库支流水华预警预报系统,提供重要的研究基础,为三峡水库支流水华防控提供有力依据。2008年5月至2009年5月研究期间,小江回水区5个采样断面间的藻类细胞密度、藻类生物量和Chla的季节变化过程同步,且藻类细胞密度(CellD)和Chla、藻类生物量(BioM)和叶绿素a(Chla)之间均呈极显著的正相关关系。研究期间小江回水区共鉴定出藻类7门,98属,259种(包括变种),其中绿藻门52属123种,占47.5%;硅藻门20属77种,占29.7%;蓝藻门15属33种,占12.7%;最常见的10个藻属分别是:隐藻、小环藻、蓝隐藻、衣藻、纤维藻、小球藻、栅藻、脆杆藻、针杆藻、浮鞘丝藻;各藻门的演替情况:甲藻门、蓝藻门→绿藻门→硅藻门→蓝藻门、甲藻门。观测期间小江回水区各采样点的优势藻表现出明显的季节演替现象,其中星杆藻、直链藻、小环藻、针杆藻、空球藻、鱼腥藻、微囊藻、浮鞘丝藻、色球藻、平裂藻、角甲藻、多甲藻和隐藻等13个藻属是小江回水区不同季节出现频次最大的优势藻。观测期间,小江回水区暴发了大小四次水华:2008年5月以角甲藻和多甲藻为主的甲藻水华;2008年7～9月的针杆藻水华;2009年3月的星杆藻水华;以及2009年4～5月以鱼腥藻为主要优势藻的固氮型蓝藻水华。对藻类与各影响因子的相关性分析发现,藻类总生物量和总细胞密度与各影响因子的相关性明显高于各优势藻属与影响因子的相关性。本研究根据Reynolds的功能分组结果,对研究期间小江回水区的藻类功能组进行了界定,研究期间藻类功能组在小江回水区的演替过程如下:LO、LM→LO、LM、B、G、Y、J、X1、H1→LO、LM、D→P、D、B、Y、F、J→B、C、P、Y→H1→B、G、Y、LM。藻类功能组与环境因子的CCA分析结果显示:温度(Temp)是对各藻类功能组在小江回水区的分布影响较为显著的环境因子,其次是pH、SiO2、透明度(SD)和磷酸盐(SRP);而环境因子NH4+-N、TN、TP和TN/TP对藻类功能组的分布影响比较小。更多还原

【Abstract】 The worldwide famous project, Three Gorges Reservoir, which has the ability of navigation, flood control and power. The project changed the entironment of Three Gorges Area greately while the large benefit to the country, and will greatly affect the entironment of Yangtse River Basin persistently. Our group has been observing the area of Xiaojiang Backwater Area of the Three Gorges Reservoir regularly for one year. The study analysed the structure of alga community and its seasonal variation; imported the concept of algal functional groups which gradually arised in the ecological research presently, in order to receal the seasonal variation of the dominant algae and alga functional groups; and studied the correlationes between dominant algae and environmental factors, and alga functional groups and environmental factors. The purpose of the sdudy is to offer basis for establishing the succession model of alga community and the forecast system of alga bloom in the Three Gorges Reservoir.In the studing period from May 2008 to May 2009, the seasonal variation of algal cell density (CellD), algal biomass(BioM) and Chla in Xiaojiang Backwater Area are Consistent. And correlativity between CellD and Chla,BioM and Chla are distinct positive. In general, 7 phyla, 98 genera and 259 species (including varieties) of phytoplankton community on the backwaters of Xiaojiang River were identified. The proportion of the community composition was: Chlorophyta, 47.5%, includes 52 genera 123 species; Bacillariophyta, 29.7%, includes 20 genera 77 species; Cyanophyta, 12.7%, includes 15 genera 33 species. The 10 generas: Cryptomonas, Cyclotella, Chlamydomonas, Ankistrodesmus, Chlorella, Scenedesmus, Fragilaria, Synedra,Planktolyngbya , are the most common algae. And the seasonal succession of the phyla is: Dinophyta, Cyanophyta→Chlorophta→Bacillariophyta→Cyanophyta, Dinophyta.In the studing period, the seasonal succession of the dominant algae in Xiaojiang Backwater Area is quite obvious. And the 13 generas: Asterionnella, Aulacoseira, Cyclotella, Synedra, Eudorina, Anabaena, Microcystis, Planktolyngbya, Chroococcus, Merismopedia, Ceratium, Peridinium, Cryptomonas, are the most dominant algae. There are 4 blooms breaked out in the studing period in Xiaojiang Backwater Area: May 2008 Ceratium bloom, July to September 2008 Synedra bloom, March 2009 Asterionnella bloom,and April to May 2009 Anabaena bloom. The analysis of the correlation between alga and the environment factors showed that the correlation coefficient between tatle alga and environment factors was much higher than the correlation coefficient between each dominant alga and environment factors.According to the function classification of Reynolds, the study defined the alga function groups in Xiaojiang Backwater Area. The seasonal succession of function groups is: LO、LM→LO、LM、B、G、Y、J、X1、H1→LO、LM、D→P、D、B、Y、F、J→B、C、P、Y→H1→B、G、Y、LM. The result of the CCA of function groups and environment factors showed that Temp is the most influential factor for the distribution of the alga function group in Xiaojiang Backwater Area, and than are the factors of pH, SiO2, SD and SRP. However, the factors of NH4+-N, TN, TP and TN/TP affected little.更多还原