Short-term N2 fixation kinetics in a moss-associated cyanobacteria

Journal Article (Academic article)

N-2 fixation by moss-associated cyanobacteria plays an important role in the nitrogen cycling of terrestrial ecosystems. Recent studies have mainly focused on boreal ecosystems; little is known about such association in other ecosystems. Moss-associated cyanobacteria are subject to rapid changes (hourly or less) in environmental conditions that may affect N-2 fixation kinetics. Using a recently developed method (Acetylene Reduction Assays by Cavity ring-down laser Absorption Spectroscopy, ARACAS) with higher sensitivity and sampling frequency than the conventional method, we characterize short-term kinetics of N-2 fixation by cyanobacteria on moss carpets from warm and cold temperate forests. We report the identification of a heretofore unknown multispecies true-moss-cyanobacteria diazotrophic association. We demonstrate that short-term change in abiotic variables greatly influences N-2 fixation. We also show that difference in relative proportion of two epiphytic diazotrophs is consistent with divergent influences of temperature on their N-2 fixation kinetics. Further research is needed to determine whether this difference is consistent with a latitudinal trend.

Full Text

Duke Authors

Cited Authors

  • Jean, M-E; Cassar, N; Setzer, C; Bellenger, JP

Published Date

  • August 2012

Published In

Volume / Issue

  • 46 / 16

Start / End Page

  • 8667 - 8671

Published By


  • 5

PubMed ID

  • 22849538

Electronic International Standard Serial Number (EISSN)

  • 1520-5851

International Standard Serial Number (ISSN)

  • 0013-936X

Digital Object Identifier (DOI)

  • 10.1021/es3018539


  • eng