{
  "abstract": "Oxygen (O ₂ ) in marsh rhizospheres varies strongly at millimetre scales due to radial oxygen loss (ROL), re-oxidation of reduced compounds, hydrology, and sediment structure. Yet many models estimate heterotrophic (microbial) respiration at a single mean O ₂ , which can bias CO ₂ fluxes because the O ₂ response of respiration is curved (nonlinear). We calibrated an enzyme kinetic respiration function to marsh-soil incubations, then compared (I) respiration evaluated at a single mean O ₂ value with (II) the mean of different respiration fluxes over a prescribed rhizosphere O ₂ distribution. To isolate oxygen effects, temperature and the relation between substrate and soil moisture were held fixed; incubations were used only to calibrate carbon kinetics. For a gas-phase, air-equivalent O ₂ proxy, the single mean approach overestimates respiration by ∼ 12 % on average. This bias increases with increasing variation of O ₂ and with the ratio of mean O ₂ to the O ₂ half-saturation constant KM,O2. In the dissolved phase, mean O ₂ ≪ KM,O2 and variation in O ₂ is small, so the bias is negligible due to linear behaviour of the relation in these conditions; when physiology is unit-matched to a similar relative saturation, however, the dissolved case shows a negative bias comparable to the gas-phase one. Our findings suggest reporting the mean and variation of O ₂ together with a calibrated KM,O2 allows modellers to anticipate or correct the bias associated with replacing heterogeneous rhizosphere conditions with a single mean.",
  "abstract_shown": true,
  "affiliations": [
    "Universität Hamburg (Hamburg, Germany)",
    "Helmholtz-Zentrum Hereon (Geesthacht, Germany)"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Youssef Saadaoui",
      "orcid": "0009-0002-7199-8755"
    },
    {
      "name": "Christian Beer",
      "orcid": "0000-0002-5377-3344"
    },
    {
      "name": "Peter Mueller"
    },
    {
      "name": "Friederike Neiske"
    },
    {
      "name": "Joscha N. Becker",
      "orcid": "0000-0002-3210-3632"
    },
    {
      "name": "Annette Eschenbach"
    },
    {
      "name": "Philipp Porada",
      "orcid": "0000-0002-5072-0220"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7wesjb5vs15by.bib",
  "cited_by": 0,
  "doi": "10.5194/bg-23-6803-2026",
  "fulltext_url": null,
  "id": "7wesjb5vs15by",
  "issns": [
    "1726-4189"
  ],
  "landing_url": "https://bg.copernicus.org/articles/23/6803/2026/",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1111|Soil Carbon and Nitrogen Dynamics"
    ]
  ],
  "openalex": "W7215917506",
  "pdf_url": "https://bg.copernicus.org/articles/23/6803/2026/bg-23-6803-2026.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-02",
  "publisher": "Copernicus GmbH",
  "ris": "https://research.draconitic.com/paper/7wesjb5vs15by.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:46Z",
      "native_id": "10.5194/bg-23-6803-2026",
      "source": "crossref",
      "url": "https://bg.copernicus.org/articles/23/6803/2026/"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "openalex:1111|Soil Carbon and Nitrogen Dynamics",
      "subfield": "hydrology-soils"
    }
  ],
  "title": "Quantifying aggregation bias in marsh carbon flux estimates caused by rhizosphere oxygen heterogeneity",
  "title_text": "Quantifying aggregation bias in marsh carbon flux estimates caused by rhizosphere oxygen heterogeneity",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:46Z",
  "url": "https://research.draconitic.com/paper/7wesjb5vs15by",
  "venue": "Biogeosciences",
  "versions": [
    {
      "doi": "10.5194/egusphere-2024-1756",
      "pid": null,
      "relation": "preprint",
      "title": null,
      "venue": null
    }
  ]
}