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Elevated CO2 does not stimulate carbon sink in a semi-arid grassland
journal contribution
posted on 2023-05-19, 23:51 authored by Song, J, Wan, S, Piao, S, Hui, D, Mark HovendenMark Hovenden, Ciais, P, Liu, Y, Zhong, M, Zheng, M, Ma, G, Zhou, Z, Ru, JElevated CO2 is widely accepted to enhance terrestrial carbon sink, especially in arid and semi‐arid regions. However, great uncertainties exist for the CO2 fertilisation effects, particularly when its interactions with other global change factors are considered. A four‐factor (CO2, temperature, precipitation and nitrogen) experiment revealed that elevated CO2 did not affect either gross ecosystem productivity or ecosystem respiration, and consequently resulted in no changes of net ecosystem productivity in a semi‐arid grassland despite whether temperature, precipitation and nitrogen were elevated or not. The observations could be primarily attributable to the offset of ecosystem carbon uptake by enhanced soil carbon release under CO2 enrichment. Our findings indicate that arid and semi‐arid ecosystems may not be sensitive to CO2 enrichment as previously expected and highlight the urgent need to incorporate this mechanism into most IPCC carbon‐cycle models for convincing projection of terrestrial carbon sink and its feedback to climate change.
Funding
Australian Research Council
History
Publication title
Ecology LettersVolume
22Pagination
458-468ISSN
1461-023XDepartment/School
School of Natural SciencesPublisher
Blackwell Publishing LtdPlace of publication
9600 Garsington Rd, Oxford, England, Oxon, Ox4 2DgRights statement
Copyright 2019 John Wiley & Sons Ltd/CNRSRepository Status
- Restricted