Litter decay controlled by temperature, not soil properties, affecting future soil carbon

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DOI

https://doi.org/10.1111/gcb.13502

Language of the publication
English
Date
2017-03-08
Type
Article
Author(s)
  • Gregorich, Edward G.
  • Janzen, Henry
  • Ellert, Benjamin H.
  • Helgason, Bobbi L.
  • Qian, Budong
  • Zebarth, Bernie J.
  • Angers, Denis A.
  • Beyaert, Ronald P.
  • Drury, Craig F.
  • Duguid, Scott D.
  • May, William E.
  • McConkey, Brian G.
  • Dyck, Miles F.
Publisher
John Wiley & Sons, Inc

Abstract

Widespread global changes, including rising atmospheric CO2 concentrations, climate warming and loss of biodiversity, are predicted for this century; all of these will affect terrestrial ecosystem processes like plant litter decomposition. Conversely, increased plant litter decomposition can have potential carbon-cycle feedbacks on atmospheric CO2 levels, climate warming and biodiversity. But predicting litter decomposition is difficult because of many interacting factors related to the chemical, physical and biological properties of soil, as well as to climate and agricultural management practices. We applied 13C-labelled plant litter to soil at ten sites spanning a 3500-km transect across the agricultural regions of Canada and measured its decomposition over five years. Despite large differences in soil type and climatic conditions, we found that the kinetics of litter decomposition were similar once the effect of temperature had been removed, indicating no measurable effect of soil properties. A two-pool exponential decay model expressing undecomposed carbon simply as a function of thermal time accurately described kinetics of decomposition. (R2 = 0.94; RMSE = 0.0508). Soil properties such as texture, cation exchange capacity, pH and moisture, although very different among sites, had minimal discernible influence on decomposition kinetics. Using this kinetic model under different climate change scenarios, we projected that the time required to decompose 50% of the litter (i.e. the labile fractions) would be reduced by 1–4 months, whereas time required to decompose 90% of the litter (including recalcitrant fractions) would be reduced by 1 year in cooler sites to as much as 2 years in warmer sites. These findings confirm quantitatively the sensitivity of litter decomposition to temperature increases and demonstrate how climate change may constrain future soil carbon storage, an effect apparently not influenced by soil properties.

Subject

  • Climate change,
  • Agriculture,
  • Air temperature,
  • Soil

Rights

Pagination

1725-1734

Peer review

Yes

Identifiers

ISSN
1365-2486

Article

Journal title
Global Change Biology
Journal volume
23
Journal issue
4
Accepted date
2016-08-23
Submitted date
2016-07-06

Citation(s)

Gregorich, E. G., Janzen, H., Ellert, B. H., Helgason, B. L., Qian, B., Zebarth, B. J., Angers, D. A., Beyaert, R. P., Drury, C. F., Duguid, S. D., May, W. E., McConkey, B. G., & Dyck, M. F. (2016). Litter decay controlled by temperature, not soil properties, affecting future Soil Carbon. Global Change Biology, 23(4), 1725–1734. https://doi.org/10.1111/gcb.13502

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Collection(s)

Climate and weather

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