近50年来环境变化对巢湖硅藻组合演替的影响  

Effects of environmental changes on the succession of diatom assemblage during the last 50 years in Lake Chaohu

作　　者：陈旭[1,2] 羊向东[1] 董旭辉[1] 刘恩峰[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,南京210008 [2]中国科学院研究生院,北京100049

出　　处：《湖泊科学》2011年第5期665-672,共8页Journal of Lake Sciences

基　　金：国家水体污染控制与治理科技重大专项项目(2008ZX07103003);国家自然科学基金项目(40972217);中国科学院知识创新工程重要方向项目(KZCX2YW319)联合资助

摘　　要：湖泊生态系统往往受营养、水文和气候等诸多环境因子的影响.区分不同环境因子的影响是揭示湖泊生态环境演化机制的关键.本文基于巢湖岩芯210Pb和137Cs测年、硅藻、地球化学指标和粒度分析结果以及流域水文、气候、人口和农业资料,利用冗余分析,定量区分1950年来营养、水文和气候对硅藻组合演替的影响.1978年前硅藻组合中Aulacoseiragranulata占绝对优势,此后耐营养种Cyclostephanos dubius大量出现.2000年以来C.dubius占绝对优势,并伴随Cyclosteph-anos tholiformis和Stephanodiscus parvus等其它耐营养种增加.结果表明,沉积物TP、TN、年均温、年均风速和水位变幅是影响硅藻组合演替的五个显著变量,它们分别单独解释硅藻组合方差的6.5%、4.7%、4.5%、4.7%和3.0%.这表明近50年来营养是巢湖硅藻组合演替的决定因素,水文过程和气候变化也是硅藻组合演替的重要诱因.Ecosystem in shallow lakes is generally subjected to the effects of multiple stressors, including nutrient, hydrology and climate. It is important to identify the impacts of multi-stressors for understanding the mechanism of environmental change in the lakes. Based on sedimentary proxies （ i. e. ,210pb and 137Cs dating, diatom, geochemical, irdicators axad particle size） from Chanhu sediment core and documentary data （i. e. , hydrology, climate, population and agriculture） in Chaohu basin, this study estimated quantitatively the effects of nutrient, hydrology and climate on diatom succession since 1950 using the redundancy analysis. Before 1978 diatom assemblages were dominated by Aulacoseira granulata, followed by an abrupt increase in eutrophic species （ i. e. Cy- clostephanos dubius）. Since 2000 diatom assemblages were characterized by C. dubius, with increases in eutrophic species （e. g. , Cyclostephanos tholiformis and Stephanodiscus parvus）. Results showed that sedimentary total phosphorus, total nitrogen, annual mean temperature, annual mean wind speed and annual water level amplitude were five significant variables, explaining solely 6.5% , 4.7% , 4.5% , 4.7% and 3.0% of the variances in diatoms respectively. Therefore, nutrient input was the most impor- tant factor on diatom succession. Meanwhile, chailges in climate and hydrological conditions also imposed an effect on diatom succession in Lake Chaohu during the last 50 years.

关 键 词：硅藻组合 营养 水文 气候 冗余分析 巢湖 

分 类 号：Q948[生物学—植物学] X171[环境科学与工程—环境科学]