Droughts Threaten Iconic Red Cedar in the Pacific Northwest

Deep inside a forest in Oregon’s Willamette Valley stands a dead 'Tree of Life.' Its foliage, normally soft and green, is tough and brown or missing altogether. Nonetheless, the tree’s reddish bark, swooping branches, and thick, conical base identify it as the Pacific Northwest’s iconic western red cedar.

A forest health specialist for the Oregon Department of Forestry, Christine Buhl, delves into the mystery behind the dead tree. With a tool called an increment borer, she extracts a sample of the tree’s inner growth rings. These rings reveal a startling truth: the tree's growth had slowed before its eventual demise, a sign that this red cedar, like thousands of others in Oregon and Washington, died from drought.

As a 'canary in the coal mine,' the red cedar serves as a dire warning. Any tree that is less drought tolerant is at risk of perishing, signaling the arrival of a changing climate. For thousands of years, red cedar has been used to craft canoes and clothing, earning it the endearing name of 'Tree of Life.' However, scientists now refer to it as the 'climate canary,' highlighting the threat it faces due to climate change-induced drought.

The red cedar's plight is not isolated. In recent years, over 15 native tree species in the Pacific Northwest have experienced declines in growth and die-offs, with 10 of them directly linked to drought and warming temperatures. These events mark the beginning of a predicted shift in tree growing ranges driven by climate change.

Trees and plants rely on specific climates for their growth, mainly dictated by temperature and moisture. Scientists have long maintained that as the atmosphere warms, growing ranges will shift higher in elevation and farther north in the Northern Hemisphere. This leaves many trees stranded in a hotter, drier world, unable to survive.

As climate mismatch becomes apparent, trees start dying off, unable to regenerate. Daniel DePinte, Forest Service aerial survey program manager, equates this phenomenon to 'Firmageddon,' referring to the massive die-off of five fir species across Oregon, Washington, and Northern California. The forests are on the move, shifting uphill as climates change.

David Shaw, a professor and forest health specialist at Oregon State University, warns that if climate change continues as predicted, Douglas fir, the region's leading commercial timber species, will experience increased mortality at higher elevations. The ongoing die-off is consistent with climate change predictions.

The combination of drought-induced stress and invasive pests proves lethal for these trees. Weakened by drought, trees become susceptible to invasive insects that would not usually be capable of killing them. It's akin to a person with a weakened immune system succumbing to the flu. The forests' reaction to climate change is evident in this disturbing pattern.

Despite the grim outlook, there is hope that red cedar might not disappear entirely. However, in areas where these trees are dying off, regeneration is unlikely unless meaningful action to address climate change is taken.

The threat facing the iconic red cedar and other tree species in the Pacific Northwest due to climate change-induced drought raises concerns. As these remarkable trees with a rich history face extinction, it is crucial that we recognize the significance of their decline and take immediate action to safeguard the future of our forests.