MM14B:
Scaling from Diazotroph Gene Diversity, Gene Expression, and Community Composition to N2 Fixation Rates Posters
MM14B:
Scaling from Diazotroph Gene Diversity, Gene Expression, and Community Composition to N2 Fixation Rates Posters
Scaling from Diazotroph Gene Diversity, Gene Expression, and Community Composition to N2 Fixation Rates Posters
Session ID#: 22248
Session Description:
The biogeographic distribution of N2 fixation has been subject to considerable debate in recent years. While traditionally thought to be restricted to the tropical surface ocean, N2 fixation has now been detected in polar regions, and has also been found “missing” in the South Pacific gyre. Moreover, several studies have reported 15N2-tracer-based rates that suggest activity by non-photosynthetic bacteria and archaea in the mesopelagic. Extrapolation of these rates suggests that N2 fixation in the deep ocean may be substantive. However some reported rates are exceedingly low, raising questions as to minimum quantifiable rates of the 15N2 tracer method. Moreover, detected nifH gene copy abundances in the mesopelagic appear insufficient to justify measured rates, and evidence for their expression in the mesopelagic depths and below is quasi non-existent.
Here we invite submissions that offer insights into the biogeographic distribution of N2 fixation. We encourage submissions that explore relationships between present (DNA) and expressed (mRNA) nifH genes, in relation to N2 fixation rate measurements, as well as studies that develop new approaches for measurements of diazotroph activity and community composition. Such efforts are critical to reconcile the diversity and function of diazotrophic communities and constrain the marine nitrogen cycle.
Primary Chair: Angelicque E White, Oregon State University, Corvallis, OR, United States
Co-chairs: Pia Moisander, University of Massachusetts Dartmouth, MA, United States and Julie Granger, University of Connecticut, Department of Marine Sciences, Groton, CT, United States
Moderators: Julie Granger, University of Connecticut, Department of Marine Sciences, Groton, CT, United States and Pia Moisander, University of Massachusetts Dartmouth, MA, United States
Student Paper Review Liaison: Angelicque E White, Oregon State University, Corvallis, OR, United States
Index Terms:
4805 Biogeochemical cycles, processes, and modeling [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
4820 Gases [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
4840 Microbiology and microbial ecology [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
4870 Stable isotopes [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
Cross-Topics:
- BN - Biogeochemistry and Nutrients
- CT - Chemical Tracers, Organic Matter and Trace Elements
Abstracts Submitted to this Session:
Getting a fix on the future of genetic methods for following diazotrophy in the marine environment (325844)
Geographical Constraints on the Abundance and Activity of Marine Diazotrophs in the North Pacific (323405)
Cold ocean nitrogen fixation (312269)
See more of: Microbiology and Molecular Ecology