Nitrogen fertilization has a stronger effect on soil nitrogen-fixing bacterial communities than elevated atmospheric CO2.

ABSTRACT: Biological nitrogen fixation is the primary supply of N to most ecosystems, yet there is considerable uncertainty about how N-fixing bacteria will respond to global change factors such as increasing atmospheric CO2 and N deposition. Using the nifH gene as a molecular marker, we studied how the community structure of N-fixing soil bacteria from temperate pine, aspen, and sweet gum stands and a brackish tidal marsh responded to multiyear elevated CO2 conditions. We also examined how N availability, specifically, N fertilization, interacted with elevated CO2 to affect these communities in the temperate pine forest. Based on data from Sanger sequencing and quantitative PCR, the soil nifH composition in the three forest systems was dominated by species in the Geobacteraceae and, to a lesser ext

SUBMITTER: Berthrong ST 

PROVIDER: S-EPMC4018900 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature