Abundance and community structure of ammonia-oxidizing bacteria and archaea in a temperate forest ecosystem under ten-years elevated CO 2

Abstract

Ammonia-oxidizing bacteria (AOB) and archaea (AOA) are considered as the key drivers of global nitrogen (N) biogeochemical cycling. Responses of the associated microorganisms to global changes remain unclear. This study was to determine if there was a shift in soil AOB and AOA abundances and community structures under free-air carbon dioxide (CO 2) enrichment (FACE) and N fertilization in Duke Forest of North Carolina, by using DNA-based molecular techniques, i.e., quantitative PCR, restriction fragment length polymorphism (RFLP) and clone library. The N fertilization alone increased the abundance of bacterial amoA gene, but this effect was not observed under elevated CO 2 condition. There w..