Climatic modifiers of the response to nitrogen deposition in peat-forming Sphagnum mosses: a meta-analysis
2011 (English)In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 191, no 2, 496-507 p.Article in journal (Refereed) Published
Peatlands in the northern hemisphere have accumulated more atmospheric carbon (C) during the Holocene than any other terrestrial ecosystem, making peatlands long-term C sinks of global importance. Projected increases in nitrogen (N) deposition and temperature make future accumulation rates uncertain. Here, we assessed the impact of N deposition on peatland C sequestration potential by investigating the effects of experimental N addition on Sphagnum moss. We employed meta-regressions to the results of 107 field experiments, accounting for sampling dependence in the data. We found that high N loading (comprising N application rate, experiment duration, background N deposition) depressed Sphagnum production relative to untreated controls. The interactive effects of presence of competitive vascular plants and high tissue N concentrations indicated intensified biotic interactions and altered nutrient stochiometry as mechanisms underlying the detrimental N effects. Importantly, a higher summer temperature (mean for July) and increased annual precipitation intensified the negative effects of N. The temperature effect was comparable to an experimental application of almost 4 g N m(-2) yr(-1) for each 1 degrees C increase. Our results indicate that current rates of N deposition in a warmer environment will strongly inhibit C sequestration by Sphagnum-dominated vegetation.
Place, publisher, year, edition, pages
2011. Vol. 191, no 2, 496-507 p.
carbon, climate, global change, meta-regression, nitrogen, peatlands, productivity, Sphagnum
IdentifiersURN: urn:nbn:se:uu:diva-156226DOI: 10.1111/j.1469-8137.2011.03680.xISI: 000292211800018OAI: oai:DiVA.org:uu-156226DiVA: diva2:431478