High-latitude tree growth and satellite vegetation indices: Correlations and trends in Russia and Canada (1982–2008)
Article first published online: 10 FEB 2011
Copyright 2011 by the American Geophysical Union.
Journal of Geophysical Research: Biogeosciences (2005–2012)
Volume 116, Issue G1, March 2011
How to Cite
2011), High-latitude tree growth and satellite vegetation indices: Correlations and trends in Russia and Canada (1982–2008), J. Geophys. Res., 116, G01015, doi:10.1029/2010JG001475., , , , and (
- Issue published online: 10 FEB 2011
- Article first published online: 10 FEB 2011
- Manuscript Accepted: 23 NOV 2010
- Manuscript Revised: 12 NOV 2010
- Manuscript Received: 7 JUL 2010
- tree ring;
- Northwest Territories
 Vegetation in northern high latitudes affects regional and global climate through energy partitioning and carbon storage. Spaceborne observations of vegetation, largely based on the normalized difference vegetation index (NDVI), suggest decreased productivity during recent decades in many regions of the Eurasian and North American boreal forests. To improve interpretation of NDVI trends over forest regions, we examined the relationship between NDVI from the advanced very high resolution radiometers and tree ring width measurements, a proxy of tree productivity. We collected tree core samples from spruce, pine, and larch at 22 sites in northeast Russia and northwest Canada. Annual growth rings were measured and used to generate site-level ring width index (RWI) chronologies. Correlation analysis was used to assess the association between RWI and summer NDVI from 1982 to 2008, while linear regression was used to examine trends in both measurements. The correlation between NDVI and RWI was highly variable across sites, though consistently positive (r = 0.43, SD = 0.19, n = 27). We observed significant temporal autocorrelation in both NDVI and RWI measurements at sites with evergreen conifers (spruce and pine), though weak autocorrelation at sites with deciduous conifers (larch). No sites exhibited a positive trend in both NDVI and RWI, although five sites showed negative trends in both measurements. While there are technological and physiological limitations to this approach, these findings demonstrate a positive association between NDVI and tree ring measurements, as well as the importance of considering lagged effects when modeling vegetation productivity using satellite data.