Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes.

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. Her...

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Bibliographic Details
Published in:Ecology Letters
Main Authors: Cornelissen, J.H.C., van Bodegom, P.M., Aerts, R., Gallaghan, T.V., van Logtestijn, R.S.P, Alatalo, J., Chapin, F.S. III, Gerdol, R., Gudmundsson, J., Gwynn-Jones, D., Hartley, A.E., Hik, D.S., Hofgaard, A., Jonsdottir, I.S., Karlsson, S., Klein, J.A., Laundre, J., Magnusson, B., Michelsel, A., Molau, U., Onipchenko, V.G., Quested, H.M., Sandvik, S.M., Schmidt, I.K., Shaver, G.R., Solhleim, B., Soudzilovskaia, N.A., Stenstrom, A., Tolvanen, A., Totland, O., Wada, N., Welker, J.M., Zhao, X., Team, M.O.L.
Format: Article in Journal/Newspaper
Language:English
Published: 2007
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Online Access:https://research.vu.nl/en/publications/c241f881-cf05-4106-b55c-e64d5805a0f4
https://doi.org/10.1111/j.1461-0248.2007.01051.x
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Summary: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. © 2007 Blackwell Publishing Ltd/CNRS.