Test Of The Intermediate Disturbance Hypothesis In The Huntai River Basin Water Ecosystem

intermediate disturbance hypothesis(IDH)that can maintain species high diversity.It is the community structure that interferes with the population into a predictable nonlinear pattern.The influence of species community structure is m ainly on the physical and chem ical characteristics of water environm ent,including water tem perature,conductivity,total dissolved solids,pH,dissolved oxygen,total nitrogen,total phosphoru s and ammonia and so on.The type of river sediment can provide living space and hidden place for aquatic organisms,Therefore,the type of river sediment has a certain im pact on the diversity of aquatic or ganisms.The study and investigated of Huntai River Basin.Physical and chemical characteristics of water environment,sediment types as basic datain in Huntai River Basin,Analysis of community structure(Shannon diversity index,species richness and evenness index)of the algae,benthic animals and fish were analyzed by principal com ponent analysis,pearson correlation an alysis and canonical correspondence analysis,screening out the m ain factors af fecting the aquatic community structure and sediment types.By m eans of multi response permutation analysis(MRPP),th e nonlinear analysis is used to fit the single peak curve,and the disturbance of the ph ysical and chemical factors,the type of the bottom in the water environment is analyzed.Results show:(1)According to the co rrelation between PCA analysis and Pearson analysis,selection of conductivity,total dissolved solids,chloride,a mmonia nitrogen,total nitrogen,hardness,permanganate index and algae diversity index of Shannon polynomial fitting analysis between the 7 factors of water environm ent and Shannon's diversity index was significantly correlated(P<0.05),and showed a single peak the curve,w ith moderate disturbance hypothesis;selection of ammonia nitrogen and active p hosphorus and algae ev enness index of polyno mial fitting analysis between the 2 factors of water env ironment and the evenness index was significantly correlated(P<0.05),and showed a single p eak curve,with intermediate disturbance hypothesis;selection of electrical conduc tivity,dissolved oxygen,total disso lved solids,chloride ion,permanganate index an d algae species richnes s of polynom ial fitting analys is,the correlation between the 5 factors of water environm ent and species richnes s Significant(P<0.05),and showed a single peak curve,in line with the intermediate disturbance hypothesis.(2)According to the co rrelation between PCA analysis and Pearson analysis,selection of chloride ions,ammonia nitrogen and potassium permanganate index and diversity index of benthic animal Shannon polynom ial fitting anal ysis,while chloride,ammonia nitrogen and potassium permanganate index and Shannon divers ity index showed a si gnificant correlation(P<0.05),but there were no single peak curve,so does not comply with intermediate disturbance hypothesis;polynomial fitting analysis of selected ammonia nitrogen,phosphorus and potassium permanganate index and activity of benthic animal evenness index,although the index of ammonia nitrogen and active phosphorus and pot assium permanganate index and evenness showed a significant correlation(P<0.05),but there were no single peak curve,so does not accord with the intermediate disturbance hypothesis;selection of ammonia nitrogen,to tal nitrogen,activity P,hardness and perm anganate index and benthic anim al species richness of polynomial fitting analysis,ammonia nitrogen Total nitrogen and active phosphorus,hardness and permanganate index and benthic anim al species richness showed a si gnificant correlation(P<0.05),and showed a single peak curve trend,so with intermediate disturbance hypothesis.(3)according to the PCA analysis on the relationship between Pearson and the results of the analysis,selection of conductiv ity,total dissolved solids and dissolved oxygen in fish and Shannon diversity index of polynom ial fitting analysis between th e 3 factors of water environment and fish Shannon diversity index was significantly correlated(P<0.05),and showed a single peak curve,with interm ediate disturbance hypothesis;sele ction the electrical conductivity,dissolved oxygen,tota l dissolved solids,ammoni a nitrogen,total nitrogen,permanganate index an d algae eve nness index of polynomial fitting analysis be tween the 6 factors of water environment and species evenness index was significantly correlated(P<0.05),and showed a single peak curve,with interm ediate disturbance hypothesis;Selection of electrical conductivity,dissolved oxygen,total dissolved solids,ammonia nitrogen and potassium permanganate index and fish species richness of polynomial fitting anal ysis,the 5 factors of water environment and fish species ric hness showed a significant correlation(P<0.05),and showed a single peak curve trend,so with intermediate disturbance hypothesis.(4)Select algae Shannon divers ity index,polynom ial fitting analysis of evenness index,species richness and IOS index,IOS index and thei r structure of algal communities significantly correlated(P<0.05),and showed a single peak curve,so with interm ediate disturbance hypothesis;selection of benthic animal diversity index,Shannon pol ynomial the fitting analysis of species richness and evenness index,IOS inde x,significant benthic animal Shannon diversity index and IOS index correlation(P<0.05),but did not show a single peak curve,so does not accord with the intermediate dis turbance hypothesis,no significan t benthic animal evenness index and IOS index correlation(P>0.05),and no showing a single peak curve,so does not accord with the intermediate disturbance hypothesis,significant benthic animal species richness and IOS index correlation(P<0.05),and presents the A single peak curve,so with interm ediate disturbance hypothesis;selection of fish divers ity index,Shannon polynomial fitting analysis of species richness and evenness index,IOS index,there was no significant correlation between the index of fish,Shannon diversity evenness index and IOS index(P>0.05),also showed a single peak curve,so does not accord with the intermediate disturbance hypothesis between fish species richness and IOS index were sign ificantly correlated(P<0.05),and showed a single peak curve,so with intermediate disturbance hypothesis.