不同浓度咪唑烟酸防除互花米草对土壤理化性质及其微生物的影响OA

To evaluate the effects of different concentrations of imazapyr on soil physical and chemical properties,soil mi-crobial diversity and community structure after controlling Spartina alterniflora,we can provide a scientific basis and techni-cal support for constructing an efficient and safe S.alterniflora control technology system.Three different sample plots(sprayed with imazapyr at concentrations of 11.940,14.925,and 17.910 L·hm-2,denoted as L1,L2,and L3,respectively)and a blank control plot(sprayed with an equal volume of clear water,denoted as L0)were set up in the S.alterniflora-invaded area along the coast of Guangxi.Soil samples at 0～20 cm depth were collected 60 days after imazapyr spraying.OTUs,α-diversity indices(Shannon,Simpson,Chao1,Pielou indices),β-diversity(PCoA),and the correlation among major microbial groups were analyzed to evaluate the characteristics of soil microbial diversity and community structure.The results showed that under different concentrations of imazapyr treatment,there were no significant differences(p>0.05)in OTUs and α-diversity indices of soil microorganisms(bacteria and fungi);the main dominant bacterial phylum in the soil bacterial community was Proteobacteria,and the main dominant fungal phyla in the soil fungal community were Ascomycota and Basidiomycota;com-pared with the control group,the relative abundances of Proteobacteria and Basidiomycota in the experimental groups showed an increasing trend,but the differences were not significant(p>0.05);PCoA of different concentration treatments showed that there was no significant difference(p>0.05)in the microbial community structure between the control group and the experi-mental groups.Imazapyr had a certain impact on the correlation among microbial communities.After application,the correla-tions among some bacterial phyla(such as Acidobacteria,Chloroflexi,Desulfobacterota,and Myxococcota)weakened,the correlation between Actinobacteria and Proteobacteria strengthened,and the correlations among saprophytic fungi(such as Ascomycota,Basidiomycota,and Zygomycota)strengthened.Imazapyr had no significant effects on soil microbial diversity or community structure.Although the use of imazapyr altered the interrelationships among some microbial groups,overall,the disturbance of imazapyr on soil microorganisms by imazapyr within the monitoring period was acceptable.