Microbial ecosystem dynamics drive fluctuating nitrogen loss in marine anoxic zones.

ABSTRACT: The dynamics of nitrogen (N) loss in the ocean's oxygen-deficient zones (ODZs) are thought to be driven by climate impacts on ocean circulation and biological productivity. Here we analyze a data-constrained model of the microbial ecosystem in an ODZ and find that species interactions drive fluctuations in local- and regional-scale rates of N loss, even in the absence of climate variability. By consuming O₂ to nanomolar levels, aerobic nitrifying microbes cede their competitive advantage for scarce forms of N to anaerobic denitrifying bacteria. Because anaerobes cannot sustain their own low-O₂ niche, the physical O₂ supply restores competitive advantage to aerobic populations, resetting the cycle. The resulting ecosystem oscillations induce a unique geochem

SUBMITTER: Penn JL 

PROVIDER: S-EPMC6462081 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature