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Regional vegetation die-off in response to global-change-type drought

Proceedings of the National Academy of Sciences of the United States of America

By:
, , , , , , , , , , , ,
DOI: 10.1073/pnas.0505734102

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Abstract

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 pin??on) 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. ?? 2005 by The National Academy of Sciences of the USA.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Regional vegetation die-off in response to global-change-type drought
Series title:
Proceedings of the National Academy of Sciences of the United States of America
DOI:
10.1073/pnas.0505734102
Volume
102
Issue:
42
Year Published:
2005
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
15144
Last page:
15148
Number of Pages:
5