Dynamics of oxidized and reduced iron in a northern hardwood forest

Colin B. Fuss, Charles T Driscoll, Chris E Johnson, Robert J. Petras, Timothy J. Fahey

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Iron (Fe) is ubiquitous in forest ecosystems and its cycle is thought to influence the development of soil, particularly Spodosols (podsolization), and the biogeochemistry of macronutrients such as carbon (C), nitrogen (N), and phosphorus (P), as well as many trace metals. The cycle of Fe in northern hardwood forests remains poorly understood. To address some of these uncertainties, we constructed a biogeochemical budget of Fe for a small catchment at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire, USA. Horizonal, temporal, and elevational patterns of concentrations and fluxes of oxidized and reduced Fe species were assessed in leaf litter, soil, soil solution, and stream water. The chemistry of dissolved Fe was evaluated in the context of its relationship with dissolved organic carbon, pH, and dissolved oxygen. Soil solution fluxes of Fe were highest in the organic (Oa, 52.5 mol ha-1 year-1) horizon and decreased with depth in the mineral (Bh, 50.5 mol ha-1 year-1, and Bs, 19.7 mol ha-1 year-1) horizons, consistent with podsolization theories predicting immobilization of Fe following downward transport to mineral soils. The export of Fe in stream water (1.8 mol ha-1 year-1) was lower than precipitation input (3.5 mol ha-1 year-1). The low stream flux indicates most Fe in drainage waters was immobilized in the soil and retained in the watershed. The portion of total Fe as Fe(II) was ~ 10-60% in soil solutions, seemingly high for soils that are considered to be well-drained, oxidizing environments. Organic complexes likely stabilized Fe(II) in solution under oxidizing conditions that would otherwise promote considerably higher Fe(III)-to-Fe(II) ratios. Our study indicates that there are organic matter-derived sources of dissolved Fe(II) as well as substantial mobilization of Fe(II), possibly the result of the reduction of Fe-bearing soil minerals.

Original languageEnglish (US)
Pages (from-to)103-119
Number of pages17
JournalBiogeochemistry
Volume104
Issue number1-3
DOIs
StatePublished - Jul 2011

Fingerprint

Hardwoods
Iron
Soils
iron
soil
Minerals
Fluxes
Water
Bearings (structural)
mineral
Biogeochemistry
Spodosol
drainage water
Dissolved oxygen
biogeochemistry
Organic carbon
Watersheds
leaf litter
Catchments
Biological materials

Keywords

  • Dissolved organic carbon
  • Fe
  • Soil solution
  • Spodosol
  • Stream water
  • Watershed

ASJC Scopus subject areas

  • Environmental Chemistry
  • Water Science and Technology
  • Earth-Surface Processes

Cite this

Dynamics of oxidized and reduced iron in a northern hardwood forest. / Fuss, Colin B.; Driscoll, Charles T; Johnson, Chris E; Petras, Robert J.; Fahey, Timothy J.

In: Biogeochemistry, Vol. 104, No. 1-3, 07.2011, p. 103-119.

Research output: Contribution to journalArticle

Fuss, Colin B. ; Driscoll, Charles T ; Johnson, Chris E ; Petras, Robert J. ; Fahey, Timothy J. / Dynamics of oxidized and reduced iron in a northern hardwood forest. In: Biogeochemistry. 2011 ; Vol. 104, No. 1-3. pp. 103-119.
@article{54ce48e34b5e41dda5b0de0639715a17,
title = "Dynamics of oxidized and reduced iron in a northern hardwood forest",
abstract = "Iron (Fe) is ubiquitous in forest ecosystems and its cycle is thought to influence the development of soil, particularly Spodosols (podsolization), and the biogeochemistry of macronutrients such as carbon (C), nitrogen (N), and phosphorus (P), as well as many trace metals. The cycle of Fe in northern hardwood forests remains poorly understood. To address some of these uncertainties, we constructed a biogeochemical budget of Fe for a small catchment at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire, USA. Horizonal, temporal, and elevational patterns of concentrations and fluxes of oxidized and reduced Fe species were assessed in leaf litter, soil, soil solution, and stream water. The chemistry of dissolved Fe was evaluated in the context of its relationship with dissolved organic carbon, pH, and dissolved oxygen. Soil solution fluxes of Fe were highest in the organic (Oa, 52.5 mol ha-1 year-1) horizon and decreased with depth in the mineral (Bh, 50.5 mol ha-1 year-1, and Bs, 19.7 mol ha-1 year-1) horizons, consistent with podsolization theories predicting immobilization of Fe following downward transport to mineral soils. The export of Fe in stream water (1.8 mol ha-1 year-1) was lower than precipitation input (3.5 mol ha-1 year-1). The low stream flux indicates most Fe in drainage waters was immobilized in the soil and retained in the watershed. The portion of total Fe as Fe(II) was ~ 10-60{\%} in soil solutions, seemingly high for soils that are considered to be well-drained, oxidizing environments. Organic complexes likely stabilized Fe(II) in solution under oxidizing conditions that would otherwise promote considerably higher Fe(III)-to-Fe(II) ratios. Our study indicates that there are organic matter-derived sources of dissolved Fe(II) as well as substantial mobilization of Fe(II), possibly the result of the reduction of Fe-bearing soil minerals.",
keywords = "Dissolved organic carbon, Fe, Soil solution, Spodosol, Stream water, Watershed",
author = "Fuss, {Colin B.} and Driscoll, {Charles T} and Johnson, {Chris E} and Petras, {Robert J.} and Fahey, {Timothy J.}",
year = "2011",
month = "7",
doi = "10.1007/s10533-010-9490-x",
language = "English (US)",
volume = "104",
pages = "103--119",
journal = "Biogeochemistry",
issn = "0168-2563",
publisher = "Springer Netherlands",
number = "1-3",

}

TY - JOUR

T1 - Dynamics of oxidized and reduced iron in a northern hardwood forest

AU - Fuss, Colin B.

AU - Driscoll, Charles T

AU - Johnson, Chris E

AU - Petras, Robert J.

AU - Fahey, Timothy J.

PY - 2011/7

Y1 - 2011/7

N2 - Iron (Fe) is ubiquitous in forest ecosystems and its cycle is thought to influence the development of soil, particularly Spodosols (podsolization), and the biogeochemistry of macronutrients such as carbon (C), nitrogen (N), and phosphorus (P), as well as many trace metals. The cycle of Fe in northern hardwood forests remains poorly understood. To address some of these uncertainties, we constructed a biogeochemical budget of Fe for a small catchment at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire, USA. Horizonal, temporal, and elevational patterns of concentrations and fluxes of oxidized and reduced Fe species were assessed in leaf litter, soil, soil solution, and stream water. The chemistry of dissolved Fe was evaluated in the context of its relationship with dissolved organic carbon, pH, and dissolved oxygen. Soil solution fluxes of Fe were highest in the organic (Oa, 52.5 mol ha-1 year-1) horizon and decreased with depth in the mineral (Bh, 50.5 mol ha-1 year-1, and Bs, 19.7 mol ha-1 year-1) horizons, consistent with podsolization theories predicting immobilization of Fe following downward transport to mineral soils. The export of Fe in stream water (1.8 mol ha-1 year-1) was lower than precipitation input (3.5 mol ha-1 year-1). The low stream flux indicates most Fe in drainage waters was immobilized in the soil and retained in the watershed. The portion of total Fe as Fe(II) was ~ 10-60% in soil solutions, seemingly high for soils that are considered to be well-drained, oxidizing environments. Organic complexes likely stabilized Fe(II) in solution under oxidizing conditions that would otherwise promote considerably higher Fe(III)-to-Fe(II) ratios. Our study indicates that there are organic matter-derived sources of dissolved Fe(II) as well as substantial mobilization of Fe(II), possibly the result of the reduction of Fe-bearing soil minerals.

AB - Iron (Fe) is ubiquitous in forest ecosystems and its cycle is thought to influence the development of soil, particularly Spodosols (podsolization), and the biogeochemistry of macronutrients such as carbon (C), nitrogen (N), and phosphorus (P), as well as many trace metals. The cycle of Fe in northern hardwood forests remains poorly understood. To address some of these uncertainties, we constructed a biogeochemical budget of Fe for a small catchment at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire, USA. Horizonal, temporal, and elevational patterns of concentrations and fluxes of oxidized and reduced Fe species were assessed in leaf litter, soil, soil solution, and stream water. The chemistry of dissolved Fe was evaluated in the context of its relationship with dissolved organic carbon, pH, and dissolved oxygen. Soil solution fluxes of Fe were highest in the organic (Oa, 52.5 mol ha-1 year-1) horizon and decreased with depth in the mineral (Bh, 50.5 mol ha-1 year-1, and Bs, 19.7 mol ha-1 year-1) horizons, consistent with podsolization theories predicting immobilization of Fe following downward transport to mineral soils. The export of Fe in stream water (1.8 mol ha-1 year-1) was lower than precipitation input (3.5 mol ha-1 year-1). The low stream flux indicates most Fe in drainage waters was immobilized in the soil and retained in the watershed. The portion of total Fe as Fe(II) was ~ 10-60% in soil solutions, seemingly high for soils that are considered to be well-drained, oxidizing environments. Organic complexes likely stabilized Fe(II) in solution under oxidizing conditions that would otherwise promote considerably higher Fe(III)-to-Fe(II) ratios. Our study indicates that there are organic matter-derived sources of dissolved Fe(II) as well as substantial mobilization of Fe(II), possibly the result of the reduction of Fe-bearing soil minerals.

KW - Dissolved organic carbon

KW - Fe

KW - Soil solution

KW - Spodosol

KW - Stream water

KW - Watershed

UR - http://www.scopus.com/inward/record.url?scp=79957835214&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79957835214&partnerID=8YFLogxK

U2 - 10.1007/s10533-010-9490-x

DO - 10.1007/s10533-010-9490-x

M3 - Article

AN - SCOPUS:79957835214

VL - 104

SP - 103

EP - 119

JO - Biogeochemistry

JF - Biogeochemistry

SN - 0168-2563

IS - 1-3

ER -