Assessing net ecosystem carbon exchange of U.S. terrestrial ecosystems by integrating eddy covariance flux measurements and satellite observations

Jingfeng Xiao, Qianlai Zhuang, Beverly E. Law, Dennis D. Baldocchi, Jiquan Chen, Andrew D. Richardson, Jerry M. Melillo, Kenneth J. Davis, David Y. Hollinger, Sonia Wharton, Ram Oren, Asko Noormets, Marc L. Fischer, Shashi B. Verma, David R. Cook, Ge Sun, Steve McNulty, Steven C. Wofsy, Paul V. Bolstad, Sean P. BurnsPeter S. Curtis, Bert G. Drake, Matthias Falk, David R. Foster, Lianhong Gu, Julian L. Hadley, Gabriel G. Katul, Marcy Litvak, Siyan Ma, Timothy A. Martin, Roser Matamala, Tilden P. Meyers, Russell K. Monson, J. William Munger, Walter C. Oechel, U. Kyaw Tha Paw, Hans Peter Schmid, Russell L. Scott, Gregory Starr, Andrew E. Suyker, Margaret S. Torn

Research output: Contribution to journalArticlepeer-review

154 Scopus citations

Abstract

More accurate projections of future carbon dioxide concentrations in the atmosphere and associated climate change depend on improved scientific understanding of the terrestrial carbon cycle. Despite the consensus that U.S. terrestrial ecosystems provide a carbon sink, the size, distribution, and interannual variability of this sink remain uncertain. Here we report a terrestrial carbon sink in the conterminous U.S. at 0.63pg C yr-1 with the majority of the sink in regions dominated by evergreen and deciduous forests and savannas. This estimate is based on our continuous estimates of net ecosystem carbon exchange (NEE) with high spatial (1km) and temporal (8-day) resolutions derived from NEE measurements from eddy covariance flux towers and wall-to-wall satellite observations from Moderate Resolution Imaging Spectroradiometer (MODIS). We find that the U.S. terrestrial ecosystems could offset a maximum of 40% of the fossil-fuel carbon emissions. Our results show that the U.S. terrestrial carbon sink varied between 0.51 and 0.70 pg C yr-1 over the period 2001-2006. The dominant sources of interannual variation of the carbon sink included extreme climate events and disturbances. Droughts in 2002 and 2006 reduced the U.S. carbon sink by ∼20% relative to a normal year. Disturbances including wildfires and hurricanes reduced carbon uptake or resulted in carbon release at regional scales. Our results provide an alternative, independent, and novel constraint to the U.S. terrestrial carbon sink.

Original languageEnglish
Pages (from-to)60-69
Number of pages10
JournalAgricultural and Forest Meteorology
Volume151
Issue number1
DOIs
StatePublished - Jan 15 2011

Keywords

  • Carbon sink
  • Disturbance
  • Drought
  • Eddy covariance
  • Interannual variability
  • MODIS
  • Net ecosystem carbon exchange
  • U.S.

Fingerprint

Dive into the research topics of 'Assessing net ecosystem carbon exchange of U.S. terrestrial ecosystems by integrating eddy covariance flux measurements and satellite observations'. Together they form a unique fingerprint.

Cite this