Revisiting the distribution of oceanic N 2 fixation and estimating diazotrophic contribution to marine production ...
Marine N 2 fixation supports a significant portion of oceanic primary production by making N 2 bioavailable to planktonic communities, in the process influencing atmosphere-ocean carbon fluxes and our global climate. However, the geographical distribution and controlling factors of marine N 2 fixati...
| Main Authors: | , , , , , , , , , |
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| Format: | Text |
| Language: | English |
| Published: |
Nature Publishing Group
2019
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.17615/z5r8-xg78 https://cdr.lib.unc.edu/concern/articles/rv0434809 |
| Summary: | Marine N 2 fixation supports a significant portion of oceanic primary production by making N 2 bioavailable to planktonic communities, in the process influencing atmosphere-ocean carbon fluxes and our global climate. However, the geographical distribution and controlling factors of marine N 2 fixation remain elusive largely due to sparse observations. Here we present unprecedented high-resolution underway N 2 fixation estimates across over 6000 kilometers of the western North Atlantic. Unexpectedly, we find increasing N 2 fixation rates from the oligotrophic Sargasso Sea to North America coastal waters, driven primarily by cyanobacterial diazotrophs. N 2 fixation is best correlated to phosphorus availability and chlorophyll-a concentration. Globally, intense N 2 fixation activity in the coastal oceans is validated by a meta-analysis of published observations and we estimate the annual coastal N 2 fixation flux to be 16.7 Tg N. This study broadens the biogeography of N 2 fixation, highlights the interplay of ... |
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