| Frequent human activities make a significant change in the type of land use in the riverbank,and these changes will have an impact on the complexity and heterogeneity of the habitat,which will change the structure of the aquatic community.Therefore,it is very important to study the effects of riverbank land use on river biota and river bank management and river ecosystem restoration.There are different types of land use in the Taizi River Basin in Liaoning Province,and the upper reaches are low hilly areas with high forest coverage,middle and lower reaches are hilly rivers and plain river areas,and the land development level is higher.In order to determine the effect of land use change on water environment and aquatic community,the main types of land use(forest land,forest land,cultivated land,urban construction land)and three species of aquatic organisms(fish,benthic,diatom)and water environment were sampled and analyzed.The results were as follows:1?the impact on the fish community: the Taizi River Basin fish functional group was divided into five types(18 sub-categories),in different land use types have significant differences in forest land within the fish food.The ratio of herbivorous and viscous egg functional groups was the highest;the ratio of herbivore and bottom habitat groups in the forest cultivated land was the highest;the sandy functional group,the middle and lower layer functional group and the nesting function group were highest proportion of the urban construction land within the sludge habitat group,the type of resistance,the lower layer of habitat function group and omnivorous functional group the highest proportion.The study shows that the number of individuals with high habitat evaluation and high habitat is high,while the habitat has low scores and the type of sediment is dominated by sludge.2?the effects of benthic fauna community: the average abundance and Shannon-Wiener diversity index in the Taizi River Basin were significantly different among different land use types,and the highest in the forest land,and the mean density,Pielou evenness index and functional group of food debris were significantly different among different land use types.The Pearson analysis between land use type and water environment factor of Taizi River shows that there is a significant negative correlation between forest land and EC,TDS,TN,NH3-N and CODMn,and there is a significant positive correlation with DO and IOS There was a significant negative correlation between agricultural land and DO and IOS.There was a positive correlation between urban land and EC,TDS and TN.Spearman analysis between land use types and benthic fauna functional groups in the Taizi River shows that forest land is positively correlated with food detox(S),scrapers(SC)and collectors(GC).There was a negative correlation between agricultural land and food debris(S)and food intake(FC),and there was a significant negative correlation between urban land use and scavenger(SC)and collector(GC).The model correspondence between the zoobenthos functional group and the water environment factor shows that the functional group of the food debris(S)is mainly driven by IOS.3?the impact on the diatom community: cluster analysis showed that the same land use type area,diatoms community structure characteristics are more similar.The model analysis shows that ?(CODMn),?(SS)(SS is suspended matter)and ?(TDS)(TDS is total dissolved solids)are the main water environmental factors that affect the structural characteristics of diatoms.The results showed that the different land use types affected the change of diatom communities through the influence of water environment factors,among which the river water quality and the diatoms were the worst in the proportion of urban construction land area.The study showed that the land use types of the Taizi River bank have significant effect on the aquatic community structure and showed obvious spatial heterogeneity. |
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