Thermodynamic constraints on the utility of ecological stoichiometry for explaining global biogeochemical patterns.

Journal Article (Journal Article)

Carbon and nitrogen cycles are coupled through both stoichiometric requirements for microbial biomass and dissimilatory metabolic processes in which microbes catalyse reduction-oxidation reactions. Here, we integrate stoichiometric theory and thermodynamic principles to explain the commonly observed trade-off between high nitrate and high organic carbon concentrations, and the even stronger trade-off between high nitrate and high ammonium concentrations, across a wide range of aquatic ecosystems. Our results suggest these relationships are the emergent properties of both microbial biomass stoichiometry and the availability of terminal electron acceptors. Because elements with multiple oxidation states (i.e. nitrogen, manganese, iron and sulphur) serve as both nutrients and sources of chemical energy in reduced environments, both assimilative demand and dissimilatory uses determine their concentrations across broad spatial gradients. Conceptual and quantitative models that integrate rather than independently examine thermodynamic, stoichiometric and evolutionary controls on biogeochemical cycling are essential for understanding local to global biogeochemical patterns.

Full Text

Duke Authors

Cited Authors

  • Helton, AM; Ardón, M; Bernhardt, ES

Published Date

  • October 2015

Published In

Volume / Issue

  • 18 / 10

Start / End Page

  • 1049 - 1056

PubMed ID

  • 26259672

Electronic International Standard Serial Number (EISSN)

  • 1461-0248

International Standard Serial Number (ISSN)

  • 1461-023X

Digital Object Identifier (DOI)

  • 10.1111/ele.12487


  • eng