Periphy Algae Communities And Their Ecologicial Groups In Response To The Micro-spatiotemporal Variations

Periphyton is as important ecological roles in the food chain and biodiversity of aquatic ecosystems,can response environmental changing sensitively and has indication mechanisms in microbiological monitoring of aquatic environment,and unique ability to remove nitrogen and phosphorus in engineering.So it has become a hot topic in water quality direction and water purification nowdays.At present,most researches focus on periphyton community dynamic monitoring,single water quality assessment,impacting factor exploration,water purification,and so on.There are fewer studies on the dynamics of micro-temporal changes,comprehensive evaluation of ecological species groups,and water purification applications.This study was conducted during the three phases of level,dry and wet period from November 2016 to July 2017.The study focused on the Yingtao River that is one of the ends of the Huangpu River and selected the periphy algae as the research object.Eighteen samples were setted to collect and identify periphyton,to analyze and summarize the three-dimensional micro-spatial changes in the horizontal,vertical,and vertical directions of the communities and the micro-time variations of short-term sampling.Based on this,X~2 Test,Spearman's rank correlation coefficient and cluster analysis were conducted to study the interspecific association degree of the algae species in this type of water and to classify the ecological species,and then to use the Pearson correlation coefficient to explore the relationship between ecological species groups and environmental factors.The water quality was evaluated comprehensively by a standardized method of fuzzy membership functions.This provides a theoretical and practical basis for the ecological classification of peithyton,the application of water purification technology,and the biological monitoring and indication of water quality as an example to the end of River in China.The main results of this study are as follows:1.During the study,identification of periphyton 71 species belonging to 44genera and 7 class(including variants,varieties),of which the Bacillariophyta 29species of 16 genera,Chlorophyta 19 species of 13 genera,Cyanophyta 9 species of 7genera,and Euglenophyta 9 species of 4 genera,Cryptophyta 2 species of 1 genera,Chrysophyta 2 species of 2 genera,and Pyrrhophyta 1 species of 1 genera.The main algae species are Bacillariophyta,followed by Chlorophyta,and the remaining algae species are relatively small.The density of species in different water period is ranked as the level period>the dry period>the wet period.The density of algae species changed during the diffetent water periods,but the proportion of different species was similar,with the largest number of diatom species.In the terms of different water period,the density changes of dry period(1.51×105 ind./cm2)>level water period(7.65×104 ind./cm2)>wet period(4.82×104 ind./cm2).The highest number is in the level period,and the highest density is in the dry period,while the number and density of algae in the wet period is the lowest.2.In terms of micro-space changes,the short distance of lateral sample sites have little effect on the number of algae species and the overall cell density,while the differences in habitats will result in differences in species and density,indicating that the feasibility and necessity of the division of ecological species groups;the longitudinal distribution of the growing periphyton has a certain regularity:in the selected study area(average river width is 18m),There are low density periphyton on the shore and in the center of the river at all the samples.when the light is normal,the periphyton density is the largest at a distance of 3m from the bank,and the light-weakened area has the highest density of periphyton at a distance of 6m from the bank;the algae in the vertical direction are low density when both closest and farthest from the water surface.while the density was relatively high at 30cm-50cm.The closest distance from the water surface was significantly changed by the tide,and the farthest was significantly constrained by the light.In terms of micro-time variations,the results of the study of different water period showed a similar pattern of change,that is,the density of periiphyton deposited in the first three days of placement was the lowest,and the time of subsequent placement increased,the density of periphyton continues to increase.By the 18th day,the density of algae on the substrate has reached a maximum value.Over 18 days,the periphyton density has begun to decline,and there are certain fluctuations in different water periods,but the overall trend is consistent.3.The dominance is Chlorella in the level period,Amolopithecus were the highest in the dry period,while the main dominant species was Blister Navicula in the wet period.The evaluation of water quality in different water periods was conducted using the methods of evaluation of dominant species,evaluation of biodiversity index,and standardized evaluation of comprehensive treatment,the results of the three water periods all showed that the water quality of the Yingtao River was in the degree of?-pollution.The results of the different methods are close relatively,and the results of the dominant species indicator method and the comprehensive evaluation method are more suitable for the evaluation of water quality at different samples,indicating that the dominant species indicator has a certain positive significance.4.The Spearman`s rank correlation coefficient is more sensitive to discriminate interspecies relationship between the Yate`s correction formula and Spearman rank correlation coefficient for the interspecific association of the main species after screening in different water periods.The proportion of positive is higher than negative about associations of different species,but the overall relationship is positive,indicating that the current mutual attraction and mutual exclusion of the periphyton communities in the Yingtao River.Although the top succession is not achieved,the periphyton trend to be interdependent and stable.According to Spearman's rank correlation coefficient calculation results,the main periphyton in different water periods can be divided into different ecological species groups,indicating different environmental conditions and water quality conditions.