Early snowmelt significantly enhances boreal springtime carbon uptake

Research output: Contribution to journalArticle

Abstract

We determine the annual timing of spring recovery from spaceborne microwave radiometer observations across northern hemisphere boreal evergreen forests for 1979–2014. We find a trend of advanced spring recovery of carbon uptake for this period, with a total average shift of 8.1 d (2.3 d/decade). We use this trend to estimate the corresponding changes in gross primary production (GPP) by applying in situ carbon flux observations. Micrometeoro-logical CO2 measurements at four sites in northern Europe and North America indicate that such an advance in spring recovery would have increased the January–June GPP sum by 29 g·C·m2 [8.4 g·C·m−2 (3.7%)/decade]. We find this sensitivity of the measured springtime GPP to the spring recovery to be in accordance with the corresponding sensitivity derived from simulations with a land ecosystem model coupled to a global circulation model. The model-predicted increase in springtime cumulative GPP was 0.035 Pg/decade [15.5 g·C·m−2 (6.8%)/decade] for Eurasian forests and 0.017 Pg/decade for forests in North America [9.8 g·C·m2 (4.4%)/decade]. This change in the springtime sum of GPP related to the timing of spring snowmelt is quantified here for boreal evergreen forests.

Details

Authors
  • Jouni Pulliainen
  • Mika Aurela
  • Tuomas Laurila
  • Tuula Aalto
  • Matias Takala
  • Miia Salminen
  • Markku Kulmala
  • Alan Barr
  • Martin Heimann
  • Anders Lindroth
  • Ari Laaksonen
  • Chris Derksen
  • Annikki Mäkelä
  • Tiina Markkanen
  • Juha Lemmetyinen
  • Jouni Susiluoto
  • Sigrid Dengel
  • Ivan Mammarella
  • Juha-Pekka Tuovinen
  • Timo Vesala
Organisations
External organisations
  • Finnish Meteorological Institute
  • University of Helsinki
  • Environment Canada
  • Max Planck Institute for Biogeochemistry
  • Lawrence Berkeley National Laboratory
  • University of Saskatchewan
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Geography

Keywords

  • Carbon uptake, Earth observation, Snowmelt
Original languageEnglish
Pages (from-to)11081-11086
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume114
Issue number42
Publication statusPublished - 2017 Oct 17
Publication categoryResearch
Peer-reviewedYes