Has this iconic Northwest tree reached tipping point?

Has this iconic Northwest tree reached tipping point?
Written by admin

INDEX – Six years have passed since Bruce Albert witnessed the sudden, inexplicable death of dozens of Western red cedars on his property.

The trees fell victim to an unnamed culprit for one summer without showing any signs of a killer pest or deadly pathogen. Nearby, Douglas firs, maples, alders, black cottonwoods, and more than a dozen surviving red cedars remain unaffected, though still undeveloped.

Albert is confused.

“There is no precedent for this,” the 70-year-old said.

Similar symptoms have been observed among red cedars throughout the Pacific Northwest.

For millennia, trees have been pillars of stability and survival for the region’s forests and its inhabitants. Scaly, blue-green leaves adorned with small, oval cones dangling from drooping branches provide sustenance for elk in winter when food is scarce. The striated wood is protected by a soft layer of iconic red bark, fibrous and forgiving, wrapped around a sturdy trunk that offers shelter for bears or useful material for humans.

Diebacks have cut down countless trees in the region, but according to emerging research, perhaps never have they been so prominent among Western red cedars or in such appreciable concentrations west of the Cascades.

Albert has watched dozens of red cedar trees grow in his yard since he moved to Snohomish County in 1976, when heat waves, droughts and wildfires were less frequent amid the region’s lush, forested corridors and abundant rainfall.

Now, over the next hill, the Bolt Creek fire has been burning since early September. nervous sign of fires on the west side summer became increasingly violent and unpredictable.

Diseased red cedars may be the latest victims of the influx of extreme weather events.

Scientists point to a changing climate as a cause, but researchers need more time to understand the nature and extent of the unseen threat to this beloved species.


Western red cedar, or Thuja plicata, is the largest tree in the Pacific Northwest and one of the oldest trees in Western Washington.

It is one of the most common conifers here, an evergreen, on the Pacific coast of North America. The species first took root in the rich soils of British Columbia thousands of years ago. Red cedar tools found at Yuquot, a small settlement on Vancouver Island, have been dated back 4,000 years.

Now it can be found in young groves and ancient forests from California to Alaska.

Sam Barr, a Samish tribal citizen and superintendent of the Stillaquamish Tribal Historic Preservation Office, relies on the tree for his art, spirituality and way of life.

“Many people refer to the cedar tree as a grandparent because it provides the most important gifts needed to survive in life,” Barr said.

He has been collecting wood materials for 14 years, using bark and wood to create art, tools, canoe paddles and drums inspired by traditional Coast Salish peoples.

Not only does the tree provide him with the materials he needs to build and carve, but it also connects him to his ancestors and their history.

Red cedar trees are used by local communities to make houses, canoes, totem poles, rope, tools, utensils, bowls, blankets, baskets, etc. used for sewing. The wood’s natural oils and buoyancy make it resistant to water and rot, making it ideal for use in boats, roofs and clothing.

White settlers also found the wood useful for deck building and fencing, a use that continues today by Northwesters throughout the region.

If the turnaround goes bad, it’s hard for Barr to fathom the loss of such an important species, especially one that’s invaluable to First Nations cultural heritage and fundamental to the region’s history and development.

“When you peel off the bark of a tree and put your hand on the bare trunk, you feel how alive the tree is, you feel the fluids flowing up and down the trunk. “You can almost feel the heartbeat of the tree.”


To investigate possible differences between healthy red cedar trees and those facing death, researchers from Washington State University, Portland State University and Reed College collected nearly 30,000 cores—small, cylindrical sections taken from inside the tree to examine their age and health. 280 red cedars at 11 sites in Washington and Oregon.

Early findings suggest that the die-off may trigger red cedar growth.

The scientists found that the species largely grew together during the early stages of the statewide drought until about seven years ago, regardless of their previous health status.

“So they grow less and less until they die,” said WSU researcher Henry Adams.

Colleague and co-author Robert Andrus said in 2015 that something happened that caused them to react very differently.

That year marked the beginning of unusually hot, dry weather in Washington that lasted until 2018.

In the past 20 years, Washington has experienced seven of its 10 warmest years since 1895. Only in the last decade has the state experienced a period of unprecedented heat. During this period, 2015 saw an unprecedented drought and rising temperatures with the infamous “hot dome”. 2021 year.

Cedar trees were given little time to recover between each bout of extreme weather.

Red cedars can usually tolerate seasonal drought or a single heat wave. But such a succession of events can gradually weaken a tree’s ability to retain water, grow, and protect itself from insects and disease.

Red cedars are particularly sensitive to climate conditions in May and June, Adams said, as they prepare for the dry season that follows.

A disruption of this cycle — like the unusually cold and wet spring weather Washington saw earlier this year — can mean the difference between life and death.

“If there’s not as much moisture during that time, they’ll grow less,” Andrus said. “And they will stop growing very early.”


For years, Climatologists have warned that global warming will destabilize the planet’s natural systems, pushing them beyond tipping points, leading to mass extinctions and the collapse of entire ecosystems.

In 2008, the British scientist Timothy Lenton identified turning point of nine planets, including the melting or retreat of ice sheets in Greenland, the West Antarctic Ocean, and East Antarctica; Disruption or disruption of ocean currents and monsoons in and around the Atlantic, West Africa, South Asia and India; and the great dead in the Amazon rainforest and boreal forest.

According to the report, these inflection points are difficult to predict because they come suddenly and may even trigger or “skip” other inflection points. For the largest of Earth’s natural systems, the process can take millions of years.

But as climate change caused by human consumption of fossil fuels continues to worsen, smaller, more localized flashpoints are expected to emerge.

Researchers fear that Western red cedars may have reached tipping point.

“You don’t know where the edge is until you cross it,” Adams said.

If red cedars have, in fact, reached this climatic point of no return, they face a dire prospect: a situation where vast areas slowly but inevitably fall victim to this decline over the coming decades or centuries. extinct – or close to it – by retreating to habitats at the edge of the habitable zone.

The Pacific Northwest suffered even greater mortality, but almost exclusively from aggressive bark beetle infestations, a fatal disease, or a fatal fungal infection.

While researchers believe the cause of Western redcedar die-off is environmental and abiotic, or abiotic, the exact cause and mechanics of it—why the trees react the way they do, which ones are most vulnerable, what can be done to stop it—still remain a mystery. . mystery.

Perhaps the trigger is unobstructed sunlight. Maybe it’s dry land. Maybe it’s low snowpack or too much competition. Perhaps species are migrating north into British Columbia, as predicted for several tree genera, as climate change alters their habitats, often pushing them to higher latitudes and elevations. Maybe all of the above.

Each situation will require a different treatment.


Weather studies Tree health and species distribution have been monitored by both state and federal governments in Washington and Oregon for nearly 80 years. But it wasn’t until 2017 that researchers began using a new label on their maps: DC, short for Dying Cedar.

Studies show that setbacks are sparsely distributed across the region, but concentrated in urban corridors and low-lying areas on the west side.

Joseph Hulbert, of WSU Forest Health Monitoring, is leading a project collecting data on red cedar from a network of community scientists. The project collected nearly 1,800 data points from 250 participants, which helped Hulbert and other researchers better understand what was happening on the ground.

In South King County’s Cedar Creek Park, the pale remains of a young red cedar stand alongside thriving maples, hemlocks and firs like a slowly decaying beacon of disaster.

Its branches were skeletal and bare, its crown colorless, and its striped trunk pockmarked with tiny holes carved by posthumous wood-boring beetles.

“It’s absolutely dead,” Glenn Kohler, a forest entomologist who studies the impact of insects on forest health, said in August.

I touched the soft shell before picking up a small patch to examine the bottom. The tree was living in a healthy grove surrounded by city corridors in King County, making good use of sunlight and showing no signs of common tree killers.

Losses are still manageable, Kohler said, unless mortality worsens.

If drought is to blame, Kohler said, reducing competition by thinning the understory can help red cedars get more water. But if it’s a combination of drought and heat, the solution may require a more tailored approach.

Melissa Fisher, expert in red cedar bottom and a forest health specialist with the state Department of Natural Resources, said red cedar trees are exposed to sunlight more often. Trees under the canopy were healthier than trees in direct sunlight.

During a drought, air bubbles drawn from dried soil can break the tree’s water column, causing the part to dry out or die. High temperatures and wind can cause the tree to dehydrate more quickly in the canopy.

In western Washington and Oregon, low spring snowpack can be associated with heavy mortality.

While these clues are helpful, it’s too early to draw conclusions.

“We only have speculations about what happened,” Fisher said.

Logging should be done carefully, he said, and perhaps more red cedar trees should be left for each acre harvested so that there is a canopy to protect them.

“The big question is: How do you handle this type of thing right now?”

About the author


Leave a Comment