Intercomparison, interpretation, and assessment of spring phenology in North America estimated from remote sensing for 1982-2006

Michael A. White, Kirsten M. de Beurs, Kamel Didan, David W. Inouye, Andrew D. Richardson, Olaf P. Jensen, John O'Keefe, Gong Zhang, Ramakrishna R. Nemani, Willem J.D. van Leeuwen, Jesslyn F. Brown, Allard de Wit, Michael Schaepman, Xioamao Lin, Michael Dettinger, Amey S. Bailey, John Kimball, Mark D. Schwartz, Dennis D. Baldocchi, John T. LeeWilliam K. Lauenroth

Research output: Contribution to journalArticlepeer-review

898 Scopus citations


Shifts in the timing of spring phenology are a central feature of global change research. Long-term observations of plant phenology have been used to track vegetation responses to climate variability but are often limited to particular species and locations and may not represent synoptic patterns. Satellite remote sensing is instead used for continental to global monitoring. Although numerous methods exist to extract phenological timing, in particular start-of-spring (SOS), from time series of reflectance data, a comprehensive intercomparison and interpretation of SOS methods has not been conducted. Here, we assess 10 SOS methods for North America between 1982 and 2006. The techniques include consistent inputs from the 8 km Global Inventory Modeling and Mapping Studies Advanced Very High Resolution Radiometer NDVIg dataset, independent data for snow cover, soil thaw, lake ice dynamics, spring streamflow timing, over 16000 individual measurements of ground-based phenology, and two temperature-driven models of spring phenology. Compared with an ensemble of the 10 SOS methods, we found that individual methods differed in average day-of-year estimates by ± 60 days and in standard deviation by ± 20 days. The ability of the satellite methods to retrieve SOS estimates was highest in northern latitudes and lowest in arid, tropical, and Mediterranean ecoregions. The ordinal rank of SOS methods varied geographically, as did the relationships between SOS estimates and the cryospheric/hydrologic metrics. Compared with ground observations, SOS estimates were more related to the first leaf and first flowers expanding phenological stages. We found no evidence for time trends in spring arrival from ground- or model-based data; using an ensemble estimate from two methods that were more closely related to ground observations than other methods, SOS trends could be detected for only 12% of North America and were divided between trends towards both earlier and later spring.

Original languageEnglish (US)
Pages (from-to)2335-2359
Number of pages25
JournalGlobal change biology
Issue number10
StatePublished - 2009
Externally publishedYes


  • Bloom
  • Budburst
  • Climate change
  • Flower
  • Growing season
  • Land surface phenology
  • Seasonality

ASJC Scopus subject areas

  • Global and Planetary Change
  • Environmental Chemistry
  • Ecology
  • General Environmental Science


Dive into the research topics of 'Intercomparison, interpretation, and assessment of spring phenology in North America estimated from remote sensing for 1982-2006'. Together they form a unique fingerprint.

Cite this