Analysis Of The Driving Force For The Spatial Distribution Of Zooplankton Community In Plateau Lakes

Because of the development of industry and agriculture,the pollution of the water environment has severely damaged the habitat of a large number of aquatic organisms,especially the zooplankton which are small but widely distributed and easily overlooked by people.Because of their sensitivity to environmental changes,zooplankton has often been used To be an indicator of the pollution of the water environment.Plateau deep-water lakes have their special ecological characteristics and are important freshwater ecosystems in the plateau region.Their biodiversity research is of great significance for diagnosing and identifying key influencing factors of freshwater ecological security in the plateau region.However,there are few reports on systematic studies of deep-water lakes in the plateau.Therefore,this study takes plateau lake?Chenghai Lake?as the research area,arranges 15 sampling points in Chenghai Lake according to the grid layout,and collects and analyzes the samples according to the water depth upper,middle and bottom,and uses macro barcodes with the help of high-throughput technology Method to analyze the composition of zooplankton community,combined with water quality and environmental factors,to clarify the distribution pattern of zooplankton community under different aquatic conditions and the distribution pattern under different water depth conditions,and to clarify the key driving factors for the formation of the spatial distribution pattern of zooplankton community.The results of this study are as follows:1?It shows that under different water depth conditions,the water environment in the south and north of Chenghai Lake is significantly different.Among them,the main difference factors in the upper layer are dissolved oxygen?DO?,Fluoride?F^—?,total nitrogen?TN?,turbidity?Turb?,oxidation-reduction potential?ORP?,total dissolved phosphorus?TDP?,total dissolved nitrogen?TDN?and ammonia nitrogen?NH₄-N?,and the main difference factors in the middle layer are TDN,TN,ORP,TDP,DO,pH,Ca,Fluoride?F^—?and Bromide?Br^—?.The main difference factors in the bottom layer are ORP,TDN,NH₄-N,and TDP.In addition,the environmental conditions at different water depths in the north are significantly different,with obvious water quality stratification.From the upper layer to the bottom layer,the concentration of chlorophyll-a?chl-a?and DO gradually decreased,and the concentration of TDP increased slightly;the stratification of water quality in the south was not obvious,and the environmental conditions at different water depths were not significant.2?It is revealed that under different water depth conditions,the zooplankton communities in the south and north of Chenghai Lake are significantly different;the zooplankton communities in the south and north are significantly different in the upper layer and the bottom layer,but the difference in different water depths in the north is higher than that in the south.In addition,the overall comparative analysis of different water depth communities found that the main dominant groups in the upper layer were rotifers and protozoa with smaller organisms.With the increase of depth,the copepods and cladocerans whose organisms are relatively large are making more contribution to the difference between north and south.In the vertical dimension,we found that the distribution of zooplankton communities in the north and south has a commonality:as the depth increases,the biological volume of the main species that cause differences in the biocommunities in the vertical direction gradually increase.3?The key environmental factors that drive the formation of the north-south differential distribution pattern of zooplankton communities under different water depths?upper,middle,and bottom?are clarified.The upper layer are pH,total organic carbon?TOC?,Turb,and the middle layer are TP,nitrate nitrogen?NO₃-N?,ORP.At the bottom,this study did not identify key environmental factors.In addition,the key environmental factors that drive the vertical distribution of zooplankton communities in the south are temperature?T?,chl-a,and DO,and the characteristic key environmental factors that drive the vertical distribution of zooplankton communities in the north are NH₄-N,TDP,F^—,and chl-a.The results of this study show that under different water depths,the key environmental factors that lead to the vertical distribution of zooplankton communities in the south and north are different.The factors carry out a systematic layered analysis of plateau deep-water lakes.Problem diagnosis and management are both important and urgent.At the same time,our research result provides a good example for the study of the biodiversity of plateau deep-water lakes,and provides an important reference for the management and protection of plateau lakes.