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
2014 (English)In: Journal of Geophysical Research - Biogeosciences, ISSN 2169-8953, Vol. 119, no 3, 392-402 p.Article in journal (Refereed) Published
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 <list list-type="bulleted" id="jgrg20166-list-0001"> <list-item id="jgrg20166-li-0001">C accumulation in nutrient-poor boreal peatlands is increased by N fertilization <list-item id="jgrg20166-li-0002">Weak effects on C accumulation induced by greenhouse warming
Place, publisher, year, edition, pages
American Geophysical Union (AGU), 2014. Vol. 119, no 3, 392-402 p.
carbon, mire, climate change, Pb-210, temperature, nitrogen
Ecology Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:umu:diva-89243DOI: 10.1002/2013JG002365ISI: 000334534500015OAI: oai:DiVA.org:umu-89243DiVA: diva2:719622