[PCA] NEWS: Tree Deaths in California's Sierra Nevada Increase as Temperatures Rise

[Olivia Kwong]

Tree Deaths in California's Sierra Nevada Increase as Temperatures Rise:
A new study by the U.S. Geological Survey reports a rising death rate for 
trees in old-growth forests of the Sierra Nevada mountain range, 
paralleling increasing summer drought due to warming temperatures. These 
findings suggest Sierran forests, and potentially other forests of dry 
climates, may be sensitive to temperature-driven increases in drought, 
making them vulnerable to die-back during otherwise normal periods of 
reduced precipitation. These results pose a challenge to forest managers. 
Forest restoration often attempts to mimic conditions prior to 
Euro-american settlement. However, if forests respond rapidly to warming 
temperatures, attaining conditions similar to this relatively cooler 
target era may not be feasible or desirable. This study, by USGS 
scientists Phil van Mantgem and Nate Stephenson, appears in Ecology 
Letters. See: http://www.werc.usgs.gov/pubbriefs/vanmantgempbaug2007.html. 
(Phil van Mantgem, Three Rivers, CA, 559-565-3179, pvanmantgem at usgs.gov) 
Citation: van Mantgem, P.J., and N.L. Stephenson. 2007. Apparent 
climatically-induced increase of mortality rates in a temperate forest. 
Ecology Letters doi: 10.1111/j.1461-0248.2007.01080.x.