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A unified theory for organic matter accumulation.
Zakem, Emily J; Cael, B B; Levine, Naomi M.
Afiliação
  • Zakem EJ; Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089; zakem@usc.edu.
  • Cael BB; Ocean Biogeochemistry and Ecosystems, National Oceanography Centre, Southampton SO14 3ZH, United Kingdom.
  • Levine NM; Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089.
Proc Natl Acad Sci U S A ; 118(6)2021 02 09.
Article em En | MEDLINE | ID: mdl-33536337
ABSTRACT
Organic matter constitutes a key reservoir in global elemental cycles. However, our understanding of the dynamics of organic matter and its accumulation remains incomplete. Seemingly disparate hypotheses have been proposed to explain organic matter accumulation the slow degradation of intrinsically recalcitrant substrates, the depletion to concentrations that inhibit microbial consumption, and a dependency on the consumption capabilities of nearby microbial populations. Here, using a mechanistic model, we develop a theoretical framework that explains how organic matter predictably accumulates in natural environments due to biochemical, ecological, and environmental factors. Our framework subsumes the previous hypotheses. Changes in the microbial community or the environment can move a class of organic matter from a state of functional recalcitrance to a state of depletion by microbial consumers. The model explains the vertical profile of dissolved organic carbon in the ocean and connects microbial activity at subannual timescales to organic matter turnover at millennial timescales. The threshold behavior of the model implies that organic matter accumulation may respond nonlinearly to changes in temperature and other factors, providing hypotheses for the observed correlations between organic carbon reservoirs and temperature in past earth climates.
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Texto completo: 1 Base de dados: MEDLINE Assunto principal: Compostos Orgânicos / Carbono / Microbiota / Modelos Teóricos Tipo de estudo: Prognostic_studies Idioma: En Ano de publicação: 2021 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Compostos Orgânicos / Carbono / Microbiota / Modelos Teóricos Tipo de estudo: Prognostic_studies Idioma: En Ano de publicação: 2021 Tipo de documento: Article