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Publication Date
5 April 2022

Global Field Observations of Tree Die-Off Reveal Hotter-Drought Fingerprint for Earth’s Forests

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Powerpoint Slide
Geo-referenced tree mortality plots (n = 1303) in the database. Dots are color coded according to the year of mortality. Each point has been precisely georeferenced. Insets show examples of dense plot networks in Canada, Central America, and Southwest Australia.

The study established a geo-referenced global database documenting climate-induced mortality events spanning all tree-supporting biomes and continents, from 154 peer-reviewed studies since 1970.


The study established a global “hotter-drought fingerprint” from tree-mortality sites—effectively a hotter and drier climate signal for tree mortality—across 675 locations encompassing 1,303 plots. The frequency of these observed mortality-year climate conditions strongly increases nonlinearly under projected warming. The study also provides an initial footing for further community-developed, quantitative, ground-based monitoring of global tree mortality. 


Earth’s forests face grave challenges in the Anthropocene, including hotter droughts increasingly associated with widespread forest die-off events. But despite the vital importance of forests to global ecosystem services, their fates in a warming world remain highly uncertain. Lacking is a quantitative determination of commonality in climate anomalies associated with pulses of tree mortality—from published, field-documented mortality events—required for understanding the role of extreme climate events in overall global tree die-off patterns.

Point of Contact
Jason Smerdon
Columbia University
University of California Los Angeles (UCLA)
Funding Program Area(s)