Widespread increase of tree mortality rates in the western United States

Publication Type:

Journal Article

Authors:

van Mantgem, Phillip J.; Stephenson, Nathan L.; Byrne, John C.; Daniels, Lori D.; Franklin, Jerry F.; Fulé, Peter Z.; Harmon, Mark E.; Larson, Andrew J.; Smith, Jeremy M.; Taylor, Alan H.; Veblen, Thomas T.

Source:

Science, American Association for the Advancement of Science (AAAS), Volume 323, Issue 5913, p.521-524 (2009)

Call Number:

A09VAN01IDUS

URL:

http://www.sciencemag.org/content/323/5913/521.abstract

Keywords:

SWAP, tree mortality, West

Abstract:

Persistent changes in tree mortality rates can alter forest structure, composition, and ecosystem services such as carbon sequestration. Our analyses of longitudinal data from unmanaged old forests in the western United States showed that background (noncatastrophic) mortality rates have increased rapidly in recent decades, with doubling periods ranging from 17 to 29 years among regions. Increases were also pervasive across elevations, tree sizes, dominant genera, and past fire histories. Forest density and basal area declined slightly, which suggests that increasing mortality was not caused by endogenous increases in competition. Because mortality increased in small trees, the overall increase in mortality rates cannot be attributed solely to aging of large trees. Regional warming and consequent increases in water deficits are likely contributors to the increases in tree mortality rates.

Notes:

ELECTRONIC FILE - Zoology

SWAP (2/19/2016) citation:
van Mantgem PJ, Stephenson NL, Byrne JC, Daniels LD, Franklin JF, Fulé PZ, Harmon ME, Larson AJ, Smith JM, Taylor AH, et al. 2009. Widespread increase of tree mortality rates in the western United States. [accessed 2015 Dec 30]; Science. 323(5913):521–524. http://www.sciencemag.org/content/323/5913/521.abstract

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