The role of ammonia-oxidizing microorganisms in the replacement of by .

We investigated the role of ammonia-oxidizing microorganisms in the process of replacement for controlling the invasive plant, . We examined the effects of replacement on the regeneration of , plant nitrogen absorption, soil nitrogen transformation, and ammonia-oxidizing microbial communities. The results demonstrated that one year after replacement, there were significant increases in soil total nitrogen (109.4%), ammonium (78.1%), and nitrate (20.3%), accompanied by a remarkable 213.0% elevation in the net nitrification rate. The ammonia-oxidizing bacteria AOB- gene copy number was significantly increased, which was positively correlated with soil total nitrogen and nitrate nitrogen. Results of random forest model analysis showed that comammox clade A.2 and AOB jointly dominated the nitrification process. The soil net nitrification rate, AOB- gene copy number, and plant tissue total nitrogen content were identified as the primary factors influencing the relative cover of . The enhanced activity of ammonia-oxidizing microorganisms improved soil nitrogen conversion efficiency, giving a competitive advantage over in nitrogen uptake and accumulation, thereby effectively inhibiting the regeneration of .