Regional vegetation die-off in response to global-change-type drought
Future drought is projected to occur under warmer temperature conditions as climate change progresses, referred to here as global-change-type drought, yet quantitative assessments of the triggers and potential extent of drought-induced vegetation die-off remain pivotal uncertainties in assessing climate-change impacts. Of particular concern is regional-scale mortality of overstory trees, which rapidly alters ecosystem type, associated ecosystem properties, and land surface conditions for decades. Here, we quantify regional-scale vegetation die-off across southwestern North American woodlands in 2002-2003 in response to drought and associated bark beetle infestations. At an intensively studied site within the region, we quantified that after 15 months of depleted soil water content, >90% of the dominant, overstory tree species (Pinus edulis, a piñon) died. The die-off was reflected in changes in a remotely sensed index of vegetation greenness (Normalized Difference Vegetation Index), not only at the intensively studied site but also across the region, extending over 12,000 km2 or more; aerial and field surveys confirmed the general extent of the die-off. Notably, the recent drought was warmer than the previous subcontinental drought of the 1950s. The limited, available observations suggest that die-off from the recent drought was more extensive than that from the previous drought, extending into wetter sites within the tree species' distribution. Our results quantify a trigger leading to rapid, drought-induced die-off of overstory woody plants at subcontinental scale and highlight the potential for such die-off to be more severe and extensive for future global-change-type drought under warmer conditions.
Citation Information
Publication Year | 2005 |
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Title | Regional vegetation die-off in response to global-change-type drought |
DOI | 10.1073/pnas.0505734102 |
Authors | D.D. Breshears, N.S. Cobb, P.M. Rich, K. P. Price, Craig D. Allen, R.G. Balice, W.H. Romme, J.H. Kastens, M. Lisa Floyd, J. Belnap, J. J. Anderson, O.B. Myers, Clifton W. Meyer |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | PNAS |
Index ID | 70027694 |
Record Source | USGS Publications Warehouse |
USGS Organization | Fort Collins Science Center |