The Research On Suitable Habitat And Environmental Threshold Of Epiphytic Algae In Taizi River

As an important part of the aquatic communities in rivers,epiphytic algae is closely related to the aquatic environment factors.Most studies at home and abroad on the relationship between the epiphytic algae community and habitat environmental factors are conducted through multivariate statistical analysis to evaluate the environmental factors that affect the spatial and temporal distribution of the epiphytic algae community.Such qualitative analysis can only judge the environmental driving factors,but cannot accurately quantify the response relationship between the epiphytic algae community and environmental factors.In muddy too river in liaoning province for example,this study based on the three whole basin water ecological investigation of ecological data of 141 stations with critical indicator species analysis(TITAN)and the weighted average of the regression analysis(WA),the quantitative evaluation of the algae community and nutrient,dissolved oxygen,nitrogen and phosphorus in river water environment and conductivity of quantitative relationship between response(most nearly and threshold).The results showed that 22 total nitrogen(TN)indicator species,29 DO indicator species,19 TP indicator species and 29 conductivity(Cond)indicator species were determined by TITAN in taizi river basin.WA analysis showed that the optimal values for TN and TP of the growing algae in taizi river were 0.025~0.47mg/L and 0.65~12.14mg/L,respectively,and the ranges of conductivity and dissolved oxygen were 168.90~702.80mg/L and 5.83~14.3mg/L.The value of shannon-wiener index of the endogenous algae(0-1)ranges from 0.09 mg/L to 375.56 s/cm,and the optimal value of conductivity and total nitrogen in each group is:(1-2)<(2-3)<(3-4)<(0-1).It can be seen that: Within a certain range,the higher the dissolved oxygen is,the lower the conductivity and total nitrogen are,and the higher the biodiversity level of the host algae community is.In addition,the shannon-wiener index(0-1)of the host algae community diversity is negatively correlated with the dissolved oxygen and total nitrogen threshold,while positively correlated with the conductivity and total phosphorus threshold.According to the habitat,tolerance and sensitivity of the symbiotic algae group,it can be divided into 15 functional groups.DO indicates that the functional group of the symbiotic algae is shallow water,clear water and mixed layer(X3),while Cond,TN and TP indicate that the functional group of the symbiotic algae is water body rich in organic matter or agricultural domestic wastewater(G).Through quantitative analysis of the algal community for water environmental factors most in turmoil and threshold value of nitrogen,phosphorus,can be relatively accurate evaluation of the algae community and rivers of quantitative relationship between response and nutrient content in the taizi river to carry out the typical nitrogen,phosphorus and other nutrients basin "pollutant discharge total amount control of river basin ecosystem management decisions and provide basic data and scientific basis for environmental protection.