High nitrogen deposition alters the decomposition of bog plant litter and reduces carbon accumulation

Luca Bragazza, Alexandre Buttler, Jonathan Habermacher, Lisa Brancaleoni, Renato Gerdol, Hannu Fritze, Peter Hanajik, Raija Laiho, David Johnson

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84 Citations (Scopus)

Abstract

Bogs are globally important sinks of atmospheric carbon (C) due to the accumulation of partially decomposed litter that forms peat. Because bogs receive their nutrients from the atmosphere, the world-wide increase of nitrogen (N) deposition is expected to affect litter decomposition and, ultimately, the rate of C accumulation. However, the mechanism of such biogeochemical alteration remains unclear and quantification of the effect of N addition on litter accumulation has yet to be done. Here, we show that 7 similar to years of N addition to a bog decreased the C similar to N ratio, increased the bacterial biomass and stimulated the activity of hydrolytic and oxidative enzymes in surface peat. Furthermore, N addition modified nutrient limitation of microbes during litter decomposition so that phosphorus became a primary limiting nutrient. Alteration of N release from decomposing litter affected bog water chemistry and the competitive balance between peat-forming mosses and vascular plants. We estimate that deposition of about 4 g similar to N similar to m-2 similar to yr-1 will cause a mean annual reduction of fresh litter C accumulation of about 40 similar to g similar to m-2 primarily as a consequence of decreased litter production from peat-forming mosses. Our findings show that N deposition interacts with both above and below ground components of biodiversity to threaten the ability of bogs to act as N-sinks, which may offset the positive effects of N on C accumulation seen in other ecosystems.

Original languageEnglish
Pages (from-to)1163-1172
Number of pages10
JournalGlobal Change Biology
Volume18
Issue number3
DOIs
Publication statusPublished - Mar 2012

Keywords

  • decomposition
  • litter accumulation modelling
  • microbial diversity
  • peatland
  • primary production
  • soil enzymatic activity
  • S phagnum
  • vascular plants
  • sphagnum mosses
  • N deposition
  • soil carbon
  • nutrient addition
  • organic-matter
  • forest soils
  • dynamics
  • availability
  • communities

Cite this

Bragazza, L., Buttler, A., Habermacher, J., Brancaleoni, L., Gerdol, R., Fritze, H., Hanajik, P., Laiho, R., & Johnson, D. (2012). High nitrogen deposition alters the decomposition of bog plant litter and reduces carbon accumulation. Global Change Biology, 18(3), 1163-1172. https://doi.org/10.1111/j.1365-2486.2011.02585.x