Preliminary Studies On Algae Community And Environmental Correlation In Ashihe River

Ashihe River as a tributary of the Songhua River, From October2013-July2014,closing autumn、sping、summer as division,we set up a total of 8 sampling p oints in this valley,Physical and chemical indicators of water were also monitored during the same period at the sampling sites. The composition of algal species and cell density in different sampling sites were examined.The diversity of their community structures were analyzed by diversity index.The relationship between algal diversity and environmental factors were analyzed by the CCA analysis and PCA analysis.On this basis, the water quality of river was evaluated in Ashihe.The main results are as follows:1. During the survey period, A total of 259 algae taxa including 245 species 13 varieties and 1 form were identified in Ashihe River belonging to7 Phylum, 9 Class, 20 Order, 32 Family, 79 genus. The greatest percentages of taxa were recorded in the Chlorophyta(99 spp.) and Bacillariophta(98 spp.) followed by Euglenophyta(31 spp.),Cyanophyta(23 spp.), Pyrrophyta(4 spp.), Cryptophyta(3 spp.), Chrysophyta(1spp.).The result of the quantitative analysis revealed that the total average cell density of the algae was 4.63×106cells/L.In comparison with other algae, Chlorophyta was the dominant, followed by Bacillariophta and Euglenophyta also dominant in some sites.2. Most of the dominant species and common species in the study area of Ashihe River downstream was pollution indicator species such as Nitzschia palea(Kützing)W.Smith、Melosira granulate(Ehrenberg)Ralfs、Cyclotella meneghiniana Kützing、Chlorella vulgaris Beijerinck、Ankistrodesmus angustus Bernard、Kirchneriela obesa(W.West)Schmidle and so on,Ashihe River upstream of dominant species is Navicula Bory、Nitzschia Hassall、Diatoma vulgare Borger、Gomphonema Ehrenberg、Cymblla Agardh and so on,Diatoma vulgare Borger belong to clean species.3. At the same time, the physical and chemical indicators in each sampling site were monitored. The analysis results shows that the water was Weak alkaline that pH was6.89-8.2; the water temperature was 9.5-26.6 ℃; the water conductivity(SpCond)was 8~45μS/CM; the dissolved oxygen(DO) was 2.89~9.65mg/L; the chemical oxygen demand(CODcr) was 8.12~43mg/L; the biological oxygen demand(BOD) was1.11-9.62mg/L;Potassium permanganate index(CODmn) was 3.46~11.9 mg/L; the total phosphorus(TP) was 0.92-2.19mg/L; the total nitrogen concentration(TN) was0.75-13.8 mg/L.There are significant differences from upstream to downstream.4. Shannon-Wiener index, Pielou index, Simpson index and Diversity threshold index were comprehensively used in the assessment of algae.H values ranged from1.172 to 3.080; J values ranged from 0.27 to0.945; D values range from 0.46 to 0.947;Dv values range from 2.53 to 4.80. The Comprehensive Evaluation of the results showed that water nutrition in the study area ranges clean to mesotrophic.5.The algal individual abundance and environment variables were examined by canonical correspondence analysis(CCA). Among sampling stations different physical and chemical indicators impact the algal community structure.The distributions were discussed in different seasons.The result of CCA indicated that SpCond and WT were important environmental variables affecting algal community structure of the Ashihe River.6. Environmental factors in different sampling sites were cluster analysis and multi-dimensional analysis of MDS by PRIMER5.0.The results show that there were certain similarities among sampling S1、S2、S3、S4 和 S5. Due to the geographical location, there were great similarities between samplingS6、S7and S8. This result was obtained with the standard determination of physical and chemical indicators of water and the algal distribution.