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Western Redcedar Dieback

Blog Post
Western red cedar trees with dieback symptoms
Researchers in Oregon and Washington are sounding the alarm about Western redcedar decline. There is some hope for the future of Western redcedar in western Oregon. Trees growing in wet areas, northern-facing slopes, and other places with plenty of water show less damage from heat and drought.
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Western Redcedars Are Struggling in Western Oregon

Have you noticed struggling Western redcedars in your neighborhood or in natural areas?

The cause for the dieback is currently unknown and under investigation. Climate change and extreme heat are possibilities. The cause(s) of the dieback will become clearer over time with more drought and dieback cycles.  See Western redcedar dieback for details.

New Study Provides More Details and Some Hope

A new study by Aaron Ramirez (assistant professor in Biology and Environmental Studies at Reed College) provides more details about the situation. The dieback is mostly impacting younger trees on the west side of the Cascade Range. Populations of Western redcedar in drier conditions on the east side of the Cascade Range are faring better. Older trees in the Willamette Valley are too.

One hypothesis for this pattern of dieback in the Willamette Valley is that older trees occupy the best habitat. Younger trees are growing in drier microclimates. Another hypothesis is that older trees might be more resilient to drought. They can access water deeper in the soil profile than younger trees.

Ramirez’s research points out that there is some hope for the future of Western redcedar in western Oregon. Trees growing in wet areas, northern-facing slopes, and other places with plenty of water are more resilient to heat and drought.

Professor of Forest Biology at the University of Washington Dave Peterson says, “One thing I’ve been hearing a lot of in the last couple of years is people giving up on Western redcedar, ‘Oh, I’m not going to plant that because it’s going to die in climate change.’ Well, you just have to be careful about where you plant it. We will have to be even more thoughtful in the future with tree planting in order to ensure that trees are going to be in resilient places on the landscape.”

Finally, researchers in British Columbia are breeding Western redcedar from dry, interior locations with trees from the west side of the Cascade Range. Results of this breeding effort, though, will take years.

To Learn more about Western redcedar dieback, see New study sounds alarm, provides hope for Western redcedars.