Yellow-cedar Trees in a Warming World

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Research Issue

[image:] Yellow-cedar decline in Southeast AlaskaThe Earth's climate has changed throughout history, with the last ice age ending about 7,000 years ago. Most past climate changes were probably caused by small shifts in our planet’s orbit, which altered the amount of solar energy our planet receives. In the current warming cycle, the Earth’s average surface temperature has risen about 2 degrees Fahrenheit since the late 19th century. This is about 10 times faster than the average rate of warming following an ice age.

While this rate of change may be imperceptible to humans, it has more serious implications for trees, which are sensitive to environmental changes and can live for hundreds of years. One vulnerable tree species is yellow-cedar, an ecologically, economically and culturally important tree species that has declined across vast areas of Alaska and British Columbia for about 100 years. This decline isn’t associated with any particular insect or disease, but because of its timing, it may be that the die-off is connected to a gradually warming climate.

Our Research

To find out if there’s a connection between a warmer climate and yellow-cedar decline, Northern Research Station scientists are checking to see if the wider annual variations in snowpack depth, shorter snow seasons, and increased rainfall may be freezing yellow-cedar trees’ shallow root systems.

Expected Outcomes

If scientists are able to confirm a connection between a warmer climate and yellow-cedar decline, the research will provide evidence of climate change to policy-makers. It will also help forest managers respond to climate change via adaptive management strategies, such as altered range suggestions and genetic selection programs.

Research Results

Krapek, John; Hennon, Paul E.; D'Amore, David V.; Buma, Brian. 2017. Despite available habitat at range edge, yellow-cedar migration is punctuated with a past pulse tied to colder conditions. Diversity and Distributions. 23(12): 1381-1392.

Hennon, Paul E., McKenzie, Carol M., D’Amore, David V., Wittwer, Dustin T., Mulvey, Robin L., Lamb, Melinda S., Biles, Frances E., and Cronn, Rich C. 2016. A climate adaptation strategy for conservation and management of yellow-cedar in Alaska. USDA Forest Service, Gen. Tech. Rep. PNW-GTR-917.

Hennon, Paul E.; D'Amore, David V.; Schaberg, Paul G.; Wittwer, Dustin T.; Shanley, Colin S. 2012. Shifting climate, altered niche, and a dynamic conservation strategy for yellow-cedar in the North Pacific coastal rainforest. BioScience. 62: 147-158.

Schaberg, Paul G.; D'Amore, David V.; Hennon, Paul E.; Halman, Joshua M.; Hawley, Gary J.2011. Do limited cold tolerance and shallow depth of roots contribute to yellow-cedar decline? Forest Ecology and Management. 262: 2142-2150.

D'Amore, David V.; Hennon, Paul E.; Schaberg, Paul G.; Hawley, Gary J. 2009. Adaptation to exploit nitrate in surface soils predisposes yellow-cedar to climate-induced decline while enhancing the survival of western redcedar: a new hypothesis. Forest Ecology and Management. 258: 2261-2268.

Schaberg, P.G.; Hennon, P.E.; D’Amore, D.V.; Hawley, G.J. 2008. Influence of simulated snow cover on the cold tolerance and freezing injury of yellow-cedar seedlings. Global Change Biology 14:1-12.

Hennon, P.; D’Amore, D.; Wittwer, D.; Johnson, A.; Schaberg, P.; Hawley, G.; Beier, C.; Sink, S.; Juday, G. 2006. Climate Warming, Reduced Snow, and Freezing Injury Could Explain the Demise of Yellow-cedar in Southeast Alaska, USA. World Resource Review 18: 427-450.

Schaberg, P.G.; Hennon, P.E.; D’Amore, D.V.; Hawley, G.J.; Borer, C.H. 2005. Seasonal differences in the cold tolerance of yellow-cedar and western hemlock trees at a site affected by yellow-cedar decline.  Can. J. For. Res. 35:2065-2070.

Research Participants

Principal Investigator

  • Paul Schaberg, US Forest Service - Northern Research Station, Research Plant Physiologist

Research Partners

  • Paul Hennon, US Forest Service, Pacific Northwest Research Station
  • Dave D’Amore, US Forest Service, Pacific Northwest Research Station
  • Gary Hawley, The University of Vermont – Senior Researcher
  • Last modified: May 16, 2019