title: Climatic modifiers of the response to nitrogen deposition in peat-forming Sphagnum mosses: a meta-analysis.
abstract: 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°C increase. Our results indicate that current rates of N deposition in a warmer environment will strongly inhibit C sequestration by Sphagnum-dominated vegetation.
authors: Nature Conservation & Plant Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708 PB Wageningen, the Netherlands.
authors: J
authors: J
authors: Limpens
authors: Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden.
authors: G
authors: G
authors: Granath
authors: Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden.
authors: U
authors: U
authors: Gunnarsson
authors: Faculty of Earth and Life Sciences, Systems Ecology, Free University of Amsterdam, De Boelelaan 1085 1081 HV Amsterdam, the Netherlands.
authors: R
authors: R
authors: Aerts
authors: Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9.
authors: S
authors: S
authors: Bayley
authors: Department of Biology and Evolution, University of Ferrara, Corso Ercole I d'Este 32, I-44100 Ferrara, Italy.|WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Wetlands Research Group, Site Lausanne, station 2, CH-1015 Lausanne, Switzerland.|Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Ecological Systems - ECOS, station 2, CH-1015 Lausanne, Switzerland.
authors: L
authors: L
authors: Bragazza
authors: Mount Holyoke College, Environmental Studies Program, Clapp Laboratory, 50 College Street, South Hadley, MA 01075, USA.
authors: J
authors: J
authors: Bubier
authors: WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Wetlands Research Group, Site Lausanne, station 2, CH-1015 Lausanne, Switzerland.|Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Ecological Systems - ECOS, station 2, CH-1015 Lausanne, Switzerland.|Laboratory of Chrono-Environnement, UMR 6249 CNRS - INRA, Université de Franche-Comté, Besançon, France.
authors: A
authors: A
authors: Buttler
authors: Aquatic Ecology and Environmental Biology, Radboud University Nijmegen, 6525 AJ Nijmegen, the Netherlands.
authors: L J L
authors: LJL
authors: van den Berg
authors: UMR 6553 ECOBIO & FR90 CAREN, Rennes University, CNRS, Campus de Beaulieu, 263 avenue du Général Leclerc, 35042 Rennes Cedex, France.
authors: A-J
authors: AJ
authors: Francez
authors: Department of Biology and Evolution, University of Ferrara, Corso Ercole I d'Este 32, I-44100 Ferrara, Italy.
authors: R
authors: R
authors: Gerdol
authors: LIN'eco, Case postale 80, 2732 Reconvilier, Switzerland.
authors: P
authors: P
authors: Grosvernier
authors: Nature Conservation & Plant Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708 PB Wageningen, the Netherlands.
authors: M M P D
authors: MMPD
authors: Heijmans
authors: Earth System Science - Climate Change, Department of Environmental Sciences, Wageningen University, PO Box 47, 6700AA Wageningen, the Netherlands.
authors: M R
authors: MR
authors: Hoosbeek
authors: Department of Animal Ecology, Justus-Liebig-University, Heinrich-Buff-Ring 26-32 (IFZ), D-35392 Giessen, Germany.
authors: S
authors: S
authors: Hotes
authors: Department of Landscape Ecology, Institute of Ecology, Tallinn University, Uus-Sadama 5, EE-10120 Tallinn, Estonia.
authors: M
authors: M
authors: Ilomets
authors: CEH Edinburgh Bush Estate Penicuik, EH26 0QB, UK.
authors: I
authors: I
authors: Leith
authors: Laboratory of Soil Biology, University of Neuchâtel, Rue Emile-Argand 11, CH-2000 Neuchâtel, Switzerland.
authors: E A D
authors: EAD
authors: Mitchell
authors: Department of Geography, McGill University, 805 Sherbrooke St. W. Montreal, QC, Canada H3A 2K6.
authors: T
authors: T
authors: Moore
authors: Soil Science, Biogeochemistry Group, Department of Forest Ecology & Management, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden.
authors: M B
authors: MB
authors: Nilsson
authors: The Norwegian Forest and Landscape Institute, Postbox 115, 1431 Ås, Norway.
authors: J-F
authors: JF
authors: Nordbakken
authors: Department of Plant Sciences, Université Laval, 2425 rue de l'Agriculture, Quebec, QC, Canada G1V 0A6.
authors: L
authors: L
authors: Rochefort
authors: Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden.
authors: H
authors: H
authors: Rydin
authors: CEH Edinburgh Bush Estate Penicuik, EH26 0QB, UK.
authors: L J
authors: LJ
authors: Sheppard
authors: Aquilon Environmental Consulting Ltd. 3111 Spence Wynd SW, Edmonton, AB, Canada T6X 0H7.
authors: M
authors: M
authors: Thormann
authors: Soil Science, Biogeochemistry Group, Department of Forest Ecology & Management, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden.
authors: M M
authors: MM
authors: Wiedermann
authors: Macaulay Land Use Research Institute, Aberdeen, UK.
authors: B L
authors: BL
authors: Williams
authors: Department of Plant Biology, Southern Illinois University Carbondale 1125 Lincoln Drive, Carbondale, IL 62901, USA.
authors: B
authors: B
authors: Xu
mesh_terms: D001499:Bayes Theorem; D057965:Carbon Sequestration / Q000502:physiology*; D002980:Climate; D017753:Ecosystem; D016014:Linear Models; D015233:Models, Statistical; D009584:Nitrogen / Q000378:metabolism*; D011891:Rain; D012621:Seasons; D012987:Soil / Q000737:chemistry*; D044003:Sphagnopsida / Q000254:growth & development / Q000502:physiology*; D013696:Temperature; D053833:Wetlands
chemical_list: D012987:Soil; D009584:Nitrogen