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Biogeochemistry

, Volume 112, Issue 1–3, pp 457–476 | Cite as

Comparison of soil organic matter dynamics at five temperate deciduous forests with physical fractionation and radiocarbon measurements

  • Karis J. McFarlane
  • Margaret S. Torn
  • Paul J. Hanson
  • Rachel C. Porras
  • Christopher W. Swanston
  • Mac A. CallahamJr.
  • Thomas P. Guilderson
Article

Abstract

Forest soils represent a significant pool for carbon sequestration and storage, but the factors controlling soil carbon cycling are not well constrained. We compared soil carbon dynamics at five broadleaf forests in the Eastern US that vary in climate, soil type, and soil ecology: two sites at the University of Michigan Biological Station (MI-Coarse, sandy; MI-Fine, loamy); Bartlett Experimental Forest (NH-BF); Harvard Forest (MA-HF); and Baskett Wildlife Recreation and Education Area (MO-OZ). We quantified soil carbon stocks and measured bulk soil radiocarbon to at least 60 cm depth. We determined surface (0–15 cm) soil carbon distribution and turnover times in free light (unprotected), occluded light (intra-aggregate), and dense (mineral-associated) soil fractions. Total soil carbon stocks ranged from 55 ± 4 to 229 ± 42 Mg C ha−1 and were lowest at MI-Coarse and MO-OZ and highest at MI-Fine and NH-BF. Differences in climate only partly explained differences in soil organic matter 14C and mean turnover times, which were 75–260 year for free-light fractions, 70–625 year for occluded-light fractions, and 90–480 year for dense fractions. Turnover times were shortest at the warmest site, but longest at the northeastern sites (NH-BF and MA-HF), rather than the coldest sites (MI-Coarse and MI-Fine). Soil texture, mineralogy, drainage, and macrofaunal activity may be at least as important as climate in determining soil carbon dynamics in temperate broadleaf forests.

Keywords

14C Carbon cycle Soil carbon Soil fractionation Soil fauna Terrestrial carbon cycle 

Abbreviations

SOM

Soil organic matter

MA-HF

Harvard Forest

NH-BF

Bartlett Forest

UMBS

University of Michigan Biological Station

MO-OZ

Missouri Ozark

fLF

Free light fraction

oLF

Occluded light fraction

DF

Dense fraction

MF

Mobilized fraction

NEE

Net ecosystem exchange of carbon

DOM

Dissolved organic matter

Notes

Acknowledgments

Don Todd helped collect and process samples. Nick Lee, Karissa N. Murray, and Alex ander S. Wang, helped with density fractionation. AmeriFlux site mentors Bob Evans, Dave Hollinger, Kevin Hosman, Jim le Moine, Bill Munger, and Steve Pallardy provided necessary help with locating plots, sampling, and providing site soil and meteorological information. Kevin Hosman and Jim le Moine provided additional feedback and field assistance. Dave Hollinger, Jim le Moine, and Bill Munger provided comments for this manuscript. David Combs, Greta Langhenry and Evelyn Wenk assisted with soil macro invertebrate surveys. Two anonymous reviewers provided helpful comments on the manuscript. This work was supported by the Director, Office of Science, Office of Biological and Environmental Research, Climate and Environmental Science Division, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 to Berkeley Lab and under Contract DE-AC52-07NA27344 to Lawrence Livermore National Laboratory and to Oak Ridge National Laboratory, managed by UT-Battelle for DOE, under contract DE-AC05-00OR22725. Climatological data for sites in Michigan were provided by the University of Michigan Biological Station, supported by the U.S. Department of Energy’s Office of Science (BER) through the Midwestern 320 Regional Center of the National Institute for Global Environmental Change under Cooperative Agreements No. DE-FC03-90ER610100, and the Midwestern Regional Center of the National Institute for Climatic Change Research at Michigan Technological University, under Award No. DE-FC02-06ER64158.

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Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  • Karis J. McFarlane
    • 1
  • Margaret S. Torn
    • 2
  • Paul J. Hanson
    • 3
  • Rachel C. Porras
    • 2
  • Christopher W. Swanston
    • 4
  • Mac A. CallahamJr.
    • 5
  • Thomas P. Guilderson
    • 1
  1. 1.Center for Accelerator Mass SpectrometryLawrence Livermore National LaboratoryLivermoreUSA
  2. 2.Earth Sciences DivisionLawrence Berkeley National LaboratoryBerkeleyUSA
  3. 3.Environmental Sciences DivisionOak Ridge National LaboratoryOak RidgeUSA
  4. 4.U.S.D.A. Forest ServiceNorthern Research StationHoughtonUSA
  5. 5.U.S.D.A. Forest ServiceSouthern Research StationAthensUSA

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