title: Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes.
abstract: Whether climate change will turn cold biomes from large long-term carbon sinks into sources is hotly debated because of the great potential for ecosystem-mediated feedbacks to global climate. Critical are the direction, magnitude and generality of climate responses of plant litter decomposition. Here, we present the first quantitative analysis of the major climate-change-related drivers of litter decomposition rates in cold northern biomes worldwide. Leaf litters collected from the predominant species in 33 global change manipulation experiments in circum-arctic-alpine ecosystems were incubated simultaneously in two contrasting arctic life zones. We demonstrate that longer-term, large-scale changes to leaf litter decomposition will be driven primarily by both direct warming effects and concomitant shifts in plant growth form composition, with a much smaller role for changes in litter quality within species. Specifically, the ongoing warming-induced expansion of shrubs with recalcitrant leaf litter across cold biomes would constitute a negative feedback to global warming. Depending on the strength of other (previously reported) positive feedbacks of shrub expansion on soil carbon turnover, this may partly counteract direct warming enhancement of litter decomposition.
authors.affiliation: Department of Systems Ecology, Faculty of Earth and Life Sciences, Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands. hans.cornelissen@ecology.falw.vu.nl
authors.forename: Johannes H C
authors.initials: JH
authors.lastname: Cornelissen
authors.forename: Peter M
authors.initials: PM
authors.lastname: van Bodegom
authors.forename: Rien
authors.initials: R
authors.lastname: Aerts
authors.forename: Terry V
authors.initials: TV
authors.lastname: Callaghan
authors.forename: Richard S P
authors.initials: RS
authors.lastname: van Logtestijn
authors.forename: Juha
authors.initials: J
authors.lastname: Alatalo
authors.forename: F Stuart
authors.initials: FS
authors.lastname: Chapin
authors.forename: Renato
authors.initials: R
authors.lastname: Gerdol
authors.forename: Jon
authors.initials: J
authors.lastname: Gudmundsson
authors.forename: Dylan
authors.initials: D
authors.lastname: Gwynn-Jones
authors.forename: Anne E
authors.initials: AE
authors.lastname: Hartley
authors.forename: David S
authors.initials: DS
authors.lastname: Hik
authors.forename: Annika
authors.initials: A
authors.lastname: Hofgaard
authors.forename: Ingibjörg S
authors.initials: IS
authors.lastname: Jónsdóttir
authors.forename: Staffan
authors.initials: S
authors.lastname: Karlsson
authors.forename: Julia A
authors.initials: JA
authors.lastname: Klein
authors.forename: Jim
authors.initials: J
authors.lastname: Laundre
authors.forename: Borgthor
authors.initials: B
authors.lastname: Magnusson
authors.forename: Anders
authors.initials: A
authors.lastname: Michelsen
authors.forename: Ulf
authors.initials: U
authors.lastname: Molau
authors.forename: Vladimir G
authors.initials: VG
authors.lastname: Onipchenko
authors.forename: Helen M
authors.initials: HM
authors.lastname: Quested
authors.forename: Sylvi M
authors.initials: SM
authors.lastname: Sandvik
authors.forename: Inger K
authors.initials: IK
authors.lastname: Schmidt
authors.forename: Gus R
authors.initials: GR
authors.lastname: Shaver
authors.forename: Bjørn
authors.initials: B
authors.lastname: Solheim
authors.forename: Nadejda A
authors.initials: NA
authors.lastname: Soudzilovskaia
authors.forename: Anna
authors.initials: A
authors.lastname: Stenström
authors.forename: Anne
authors.initials: A
authors.lastname: Tolvanen
authors.forename: Ørjan
authors.initials: Ø
authors.lastname: Totland
authors.forename: Naoya
authors.initials: N
authors.lastname: Wada
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Welker
authors.forename: Xinquan
authors.initials: X
authors.lastname: Zhao
mesh_terms: D000704:Analysis of Variance; D002244:Carbon / Q000737:chemistry; D003081:Cold Climate; D017753:Ecosystem; D017752:Greenhouse Effect; D008954:Models, Biological; D063245:Plant Development; D018515:Plant Leaves / Q000378:metabolism*; D010944:Plants / Q000378:metabolism; D013045:Species Specificity; D013548:Sweden
chemical_list: D002244:Carbon