Title: Temperature as a potent driver of regional forest drought stress and tree mortality
Document Type: Journal
Author(s): A. Park Williams; Craig D. Allen; Alison K. Macalady; Daniel Griffin; Connie Woodhouse; David M. Meko; Thomas W. Swetnam; Sara A. Rauscher; Richard Seager; Henri D. Grissino-Mayer; Jeffrey S. Dean; Edward R. Cook; Chandana Gangodagamage; Michael Cai; Nate G. McDowell
Publication Year: 2012

Cataloging Information

climate change; drought stress; FDSI - forest drought stress index; temperature change; tree mortality
Record Maintained By: FRAMES Staff;
Record Last Modified: 09/29/2014 - 02:03
FRAMES Record Number: 13642

As the climate changes, drought may reduce tree productivity and survival across many forest ecosystems; however, the relative influence of specific climate parameters on forest decline is poorly understood. We derive a forest drought-stress index (FDSI) for the southwestern United States using a comprehensive tree-ring data set representing AD 1000-2007. The FDSI is approximately equally influenced by the warm-season vapour-pressure deficit (largely controlled by temperature) and cold-season precipitation, together explaining 82% of the FDSI variability. Correspondence between the FDSI and measures of forest productivity, mortality, bark-beetle outbreak and wildfire validate the FDSI as a holistic forest-vigour indicator. If the vapour-pressure deficit continues increasing as projected by climate models, the mean forest drought-stress by the 2050s will exceed that of the most severe droughts in the past 1,000 years. Collectively, the results foreshadow twenty-first-century changes in forest structures and compositions, with transition of forests in the southwestern United States, and perhaps water-limited forests globally, towards distributions unfamiliar to modern civilization.

Online Link(s):
Williams, A. Park; Allen, Craig D.; Macalady, Alison K.; Griffin, Daniel; Woodhouse, Connie A.; Meko, David M.; Swetnam, Thomas W.; Rauscher, Sara A.; Seager, Richard; Grissino-Mayer, Henri D.; Dean, Jeffrey S.; Cook, Edward R.; Gangodagamage, Chandana; Cai, Michael; McDowell, Nate G. 2012. Temperature as a potent driver of regional forest drought stress and tree mortality. Nature Climate Change 3:292-297.