Studied On Algae Taxonomy And Ecology In Tongjiang Of Sanjiang Plain Wetland

Sanjiang Plain is located in the northeast of Heilongjiang Province, it covers10.89×104km2and lies between130°13’-135°19’E and45°01’-48°19’N, SanjiangPlain is the largest plain swamp wetland area in China.Tongjiang is located inhinderland of Sanjiang Plain, the south coast of the intersection between Heilongjiangand Songhuajiang. There are still thirteen rivers and lots of swamps except for theHeilongjiang and Songhuajiang, and biological diversity is very rich. Sanjiang plainwetland is one of the diversiform and complete primitive wetlands among the sametype in China, it is typical of temperate wetland ecosystem in the global.Algae assemblages were investigated in Tongjiang of Sanjiang Plain Wetland, inJune of2012and July of2013.13sampling sites were selected, which consist of thelarge open water bodies, the small closed water bodies, the wetland water bodies, andthe river water bodies. Samples were collected48sample bottles. Physical andchemical indicators of water were also monitored during the same period at thesampling sites. Meanwhile, we investigated the composition of algal species, celldensity and dominant species. Diversity index was used to analyze algae diversitystructure in the study area. The Cluster analysis and MDS analysis were used ingrouping sampling sites for studying the similarity between algae communitycomposition in different sampling sites. On the basis of the above research，waterquality was evaluated in order to provide basic biological information for theprotection and construction of Tongjiang of Sanjiang Plain Wetland. The results are asfollows:1. During the survey period,402taxa (including350species,46varieties and6forms) were identified, belonging to8divisions,10classes,22orders,36families,108genera, in Tongjiang of Sanjiang Plain Wetland. The greatest percentages of taxawere recorded in the Chlorophyta (155spp.) and Bacillariophta (146spp.) followedby Euglenophyta (65spp.), Cyanophyta (23spp.), Pyrrophyta (4spp.), Xanthophta(4spp.), Cryptophyta (4spp.), Chrysophyta (1spp.). The result of the quantitativeanalysis revealed that the total average cell density of the algae was98.06×104ind./L.2. Comparison with the community structure of algae in different water bodies.Chlorophyta was dominant group in the large open water bodies from2012to2013.The dominant species in the large open water bodies were Scenedesmus dimorphus,Nitzschia palea, Stephanodiscus niagarae, Melosira granulate. Algal community structures were the most complex of all habitats in the small closed water bodies. Thedominant species were Mougeotia Agardh, Spirogyra Link, Coelastrum microporum,Tetrastrum glabrum. Most dominant species were found to be responsible foreutrophication and organic pollution. Algae were the least in the wetland water bodies.The wetland water bodies were influenced by human activities and several indicatorspecies for organic pollution were found, such as Trachelomonas oblonga,Trachelomonas hisoida. At the same time, some taxa that were characteristic of thewetland habitats (such as Cryptomonas ovata, Cryptomonas erosa) were identified inthe wetland water bodies and they were dominant species. In the river water bodies,most river was flowingand diatoms were dominant group, such as Naviculacryptocephala、Cyclotella meneghiniana.3. Margalef index, Shannon-Wiener index, Pielou index, Simpson index andDiversity threshold index were comprehensively used in the assessment of algae. Hvalues ranged from1.19to4.91, H’ values ranged from1.22to3.57, J values rangedfrom0.28to0.93, D values range from0.44to0.94, DV values ranged from1.06to4.39. The analysis showed that water nutrition ranges oligotrophic to mesotrophic inTongjiang of Sanjiang Plain Wetland, but water quality in2013was better than2012.4. Within the two years of this research, physical and chemical indicators weremeasured. A large number of algae found in studies area were alkalibiontic andmedium-strong electrolyte, the distribution of these taxa was consistent with theenvironmental characteristics of sampling sites. The quality of water was evaluated byindicator evaluation method and Palmer Index assessment. The result showed that thegreat majority of algae belong to β-mesosaprobic zone indicators and α-mesosaprobiczone indicators, a handful of algae were oligosaprobic. The evaluation showed thatthe water nutrition level of Tongjiang of Sanjiang Plain Wetland was mesosaprobic.5. Taking use of PRIMER5.0and Bray-Curtis similarity matrix, we madeCluster analysis and MDS to the sampling points of algae. The results showed thatphytoplankton population structure obviously changes in Tongjiang of Sanjiang PlainWetland during two years, and MDS stress is less than0.2. Practice has proved thatCluster analysis and MDS fit for each other, revealing the relationship betweencommunities.