The effects of temperature and nitrogen and sulfur additions on carbon accumulation in a nutrient-poor boreal mire: Decadal effects assessed using 210Pb peat chronologies

Abstract

Boreal peatlands are a major long-term reservoir of atmospheric carbon (C) and play an important role in the global C cycle. It is unclear how C accumulation in peatlands responds to changing temperatures and nutrients (specifically, nitrogen and sulfur). In this study, we assessed how the C input rate and C accumulation rate in decadal old peat layers respond to increased air temperatures (+3.6 degrees C) during the growing season and the annual additions of nitrogen (N) and sulfur (S) (30 and 20kgha(-1)yr(-1), respectively) over 12years of field treatments in a boreal mire. An empirical mass balance model was applied to Pb-210-dated peat cores to evaluate changes in C inputs, C mass loss, and net C accumulation rates in response to the treatments. We found that (i) none of the treatments generated a significant effect on peat mass loss decay rates, (ii) C input rates were positively affected by N additions and negatively affected by S additions, (iii) the C accumulation rate in the uppermost (10 to 12cm) peat was increased by N additions and decreased by S additions, and (iv) only air temperature significantly affected the main effects induced by N and S additions. Based on our findings, we argue that C accumulation rates in surface peat layers of nutrient-poor boreal mires can increase despite the predicted rise in air temperatures as long as N loads increase and acid atmospheric S remains low.Key Points C accumulation in nutrient-poor boreal peatlands is increased by N fertilization Weak effects on C accumulation induced by greenhouse warming

Keywords

carbon; mire; climate change; Pb-210; temperature; nitrogen

Published in

Journal of Geophysical Research: Biogeosciences
2014, volume: 119, number: 3, pages: 392-402

SLU Authors

• Nilsson, Mats

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    

• Eriksson, Tobias

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    

• Klaminder, Jonatan

  • Umeå University

Global goals (SDG)

SDG13 Climate action

UKÄ Subject classification

Forest Science

Publication identifier

• DOI: https://doi.org/10.1002/2013JG002365

Permanent link to this page (URI)

https://res.slu.se/id/publ/64059