We investigated the role of ammonia-oxidizing microorganisms in the process of Pueraria lobata replacement for controlling the invasive plant, Mikania micrantha. We examined the effects of P. lobata replacement on the regeneration of M. micrantha, plant nitrogen absorption, soil nitrogen transformation, and ammonia-oxidizing microbial communities. The results demonstrated that one year after P. lobata 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-amoA 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-amoA gene copy number, and plant tissue total nitrogen content were identified as the primary factors influencing the relative cover of P. lobata. The enhanced activity of ammonia-oxidizing microorganisms improved soil nitrogen conversion efficiency, giving P. lobata a competitive advantage over M. micrantha in nitrogen uptake and accumulation, thereby effectively inhibiting the regeneration of M. micrantha.
本文对氨氧化微生物在粉葛替代控制入侵植物薇甘菊过程中的作用进行了研究,分析了粉葛替代对薇甘菊再生、植物组织氮素吸收、土壤氮素转化及氨氧化微生物群落的影响。结果表明: 在粉葛替代控制1年后,土壤总氮、铵态氮和硝态氮分别显著增加了109.4%、78.1%和20.3%,净硝化速率显著提高了213.0%;氨氧化细菌AOB-amoA基因拷贝数显著增加,并与土壤总氮、硝态氮呈显著正相关。随机森林模型分析表明,完全氨氧化菌comammox clade A.2和氨氧化细菌AOB共同主导了净硝化作用,土壤净硝化速率、AOB-amoA基因拷贝数和植物组织总氮含量是粉葛相对盖度增加的主要影响因子。氨氧化微生物活性的增强提高了土壤氮素转化效率,使粉葛在氮素吸收与积累方面优于薇甘菊,有效抑制了薇甘菊的再生。.
Keywords: