Record Details
Diversity trumps acidification: Lack of evidence for carbon dioxide enhancement of Trichodesmium community nitrogen or carbon fixation at Station ALOHA
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Diversity trumps acidification: Lack of evidence for carbon dioxide enhancement of Trichodesmium community nitrogen or carbon fixation at Station ALOHA |
| Names |
Gradoville, Mary R.
(creator) White, Angelicque E. (creator) Böttjer, Daniela (creator) Church, Matthew J. (creator) Letelier, Ricardo M. (creator) |
| Date Issued | 2014-05 (iso8601) |
| Note | This is the publisher’s final pdf. The published article is copyrighted by the Association for the Sciences of Limnology and Oceanography, Inc. and can be found at: http://aslo.org/lo/. |
| Abstract | We conducted 11 independent short-term carbon dioxide (CO₂) manipulation experiments using colonies of the filamentous cyanobacteria Trichodesmium isolated on three cruises in the North Pacific Subtropical Gyre (NPSG). Dinitrogen (N₂) and carbon (C) fixation rates of these colonies were compared over CO₂ conditions ranging from ~ 18 Pa (equivalent to last glacial maximum atmospheric P[subscript CO₂]) to ~ 160 Pa (predicted for ~ year 2200). Our results indicate that elevated P[subscript CO₂] has no consistent significant effect on rates of N₂ or C fixation by Trichodesmium colonies in the NPSG under present environmental conditions. Differences between P[subscript CO₂] treatments were not modulated by phosphorus amendments, iron amendments, or light level. Sequencing the hetR, nifH, 16S, and internal transcribed spacer genes of Trichodesmium colonies revealed a highly diverse community of Trichodesmium and other N₂-fixing colony-associated organisms. The species composition of Trichodesmium demonstrated spatiotemporal variability, but over half of total sequences were phylogenetically closely related (> 99% hetR sequence similarity) to isolate H9-4 of T. erythraeum, which showed no response to elevated P[subscript CO₂] in previous laboratory experiments. Our handpicked Trichodesmium colonies included a substantial number of organisms other than Trichodesmium with the metabolic capacity for N₂ and C fixation. We suggest that the diverse assemblage of Trichodesmium species and coexisting microorganisms within the colonies can explain the lack of an observed CO₂ enhancement of N₂ or C fixation rates, because different species are known to have different specific affinities for CO₂. |
| Genre | Article |
| Topic | Marine Cyanobacterium Trichodesmium |
| Identifier | Gradoville, M. R., White, A. E., Böttjer, D., Church, M. J., & Letelier, R. M. (2014). Diversity trumps acidification: Lack of evidence for carbon dioxide enhancement of Trichodesmium community nitrogen or carbon fixation at Station ALOHA. Limnology and Oceanography, 59(3), 645-659. doi:10.4319/lo.2014.59.3.0645 |
