Studies On The Periphytic Algae In The Sichuan Section Of The Rare And Unique Fish National Nature Reserve On Yangtze Upriver

The purpose of this study was to provide scientific data for protecting the ecological environment of the rare and unique fish national nature reserve on Yangtze upriver and to further the development and adoption of practical,concrete and effective measures in order to control water quality deterioration by the primary research of the spatial and temporal changes of species composition,structure of periphytic algae in the Sichuan section of the rare and unique fish national nature reserve on Yangtze upriver.There were five sampling stations.Follow as Yibin segment of the Jinsha River,Yibin segment of the Minjiang River,Luolongchang,Naxi and Mituo.Sample need be collected four times in one year.Collection times were Apr.2007,Sept.2007,Mar.2008 and May 2008.After the investigation and research in a year,109 species of periphytic algaes,under the membership of 7 divisions,43 genuses,were found.The species belonged to Bacillariophyta, Chlorophyta,Xanthophyta,Chrysophyta,Cyanophyta,Cryptophyta and Euglenophyta.Among them,Bacillariophyta was the dominant division all year,The temporal and spatial variation of periphytic algae species composition was showed obviously.The spatial variation of periphytic algae species composition was Luolongchang＞Naxi＞Yibin segment of the Jinsha River and Yibin segment of the Minjiang River＞Mituo.The maximum number of periphytic algae species was found in Sept.2007.The periphytic algae species in Apr.2007,Mar.2008 and May 2008 was more.At the same time,the density,biomass and diversity index of periphytic algae species showed obvious temporal and spatial variation.The temporal and spatial variation of the density, and biomass of periphytic algae species was the same.The maximum number of the density,and biomass was found in Luolongchang and Yibin segment of the Minjiang River.The minimum number of the density,and biomass was found in Mituo.The diversity index of periphytic algae species composition in all sampling stations was to jarless.The diversity index of periphytic algae species composition had charges at different time. The maximum value of Shannon-Weaver diversity index was found in Mituo,in Sept.2007,Mar. 2008 and May 2008.The minimum was found in Luolongchang.The maximum value of Pielou's index was found in Mituo in this year.But the maximum value of Margalef' s index was found in Yibin segment of the Minjiang River.The change of Margalef's index were same in different mouths and was Yibin segment of the Minjiang River＞Yibin segment of the Jinsha River＞Naxi＞Luolongchang＞Mituo.By the indicator periphytic algae,the water quality of the reserve can be monitored.The water could be polluted lightly.The result of correlation analysis showed some new indicator periphytic algae.G.constrictum and S.amphicephala can denotedβ-mesosaprobic and oligosaprobic.N.radiosa can denotedβ-mesosaprobic.S.affinis,N.minima,N.simplex and N. vinridula can denotedβ-mesosaprobic andα-mesosaprobic...