Publication
Title
Weakening temperature control on the interannual variations of spring carbon uptake across northern lands
Author
Abstract
Ongoing spring warming allows the growing season to begin earlier, enhancing carbon uptake in northern ecosystems(1-3). Here we use 34 years of atmospheric CO2 concentration measurements at Barrow, Alaska (BRW, 71 degrees N) to show that the interannual relationship between spring temperature and carbon uptake has recently shifted. We use two indicators: the spring zero-crossing date of atmospheric CO2 (SZC) and the magnitude of CO2 drawdown between May and June (SCC). The previously reported strong correlation between SZC, SCC and spring land temperature (ST) was found in the first 17 years of measurements, but disappeared in the last 17 years. As a result, the sensitivity of both SZC and SCC to warming decreased. Simulations with an atmospheric transport model(4) coupled to a terrestrial ecosystem model(5) suggest that the weakened interannual correlation of SZC and SCC with ST in the last 17 years is attributable to the declining temperature response of spring net primary productivity (NPP) rather than to changes in heterotrophic respiration or in atmospheric transport patterns. Reduced chilling during dormancy and emerging light limitation are possible mechanisms that may have contributed to the loss of NPP response to ST. Our results thus challenge the 'warmer spring-bigger sink' mechanism.
Language
English
Source (journal)
Nature climate change
Publication
2017
ISSN
1758-678X
1758-6798
Volume/pages
7 :5 (2017) , p. 359-+
ISI
000400373500017
Full text (Publisher's DOI)
Full text (open access)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Project info
Effects of phosphorus limitations on Life, Earth system and Society (IMBALANCE-P).
Global Ecosystem Functioning and Interactions with Global Change.
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 02.08.2018
Last edited 19.10.2021
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