More on Western Redcedar

Spring 2018

In last spring’s issue of Tree Talk we addressed two important questions regarding the high value of western redcedar logs: 1) What is causing these inflated prices?  And 2) How long this trend will last?

(If you missed this article and are curious, you can catch up by going to our website, inlandforest.com, where a number of our past newsletters are available.)

In this article we’ll take a deeper look into the life of this unique species and touch on some of its special management needs.

It’s all in a name. Western redcedar’s scientific name is Thuja plicata, i.e. aromatic (Thuja) folded in patterns (plicata). Commonly, we call the tree western redcedar rather than red cedar because it is not a true cedar. True cedars are native to the Middle and Far East and are quite different from redcedar. The redcedar also falls within a group of trees known as arborvitaes (literally tree of life) and is sometimes called giant arborvitae. Early Native Americans along the Pacific Coast called the tree “long life maker” because it provided them with essentials such as medicines, food, clothing, lodging, totems, and transportation (“canoe cedar”). Western redcedar was so highly regarded in traditional cultures that religious ceremonies were held on the rare occasion when a tree was felled for a totem or canoe.

Long life of the western redcedar. In describing the life of a redcedar, our story could begin on any number of Pacific Northwest sites supported by maritime climatic influences, inside an elevation range of near zero to over 6,000 feet. In the Inland Northwest, the setting could range from a river bottom or moist upland forest just south of Grangeville, Idaho to Prince George, British Columbia.

As an example, let’s travel east of Bovill, ID about 25 miles up the Elk River to a tree that possibly started growing about the time Homer wrote The Iliad and The Odyssey.

Our tree most likely took root following some type of disturbance. Western redcedar (RC) seeds germinate best in openings on mineral soil or on sites prepared by fire. Although RC is a very prolific seeder, if the seed falls on an undisturbed forest floor survival is unlikely.  Also, the seed source for our special tree must have been fairly close because, although light, the cedar’s winged seed has difficulty traveling more than 400 feet from its source. Possibly our tree began its life through vegetative reproduction, which RC is capable of under the right conditions, especially in moister forests.

Once established, our young tree faced many challenges. For example, until its roots became well-situated it was very vulnerable to summer drought. A nearby spring likely gave our seedling an advantage here. Harsh winters and the lack of summer moisture continued to make life difficult. Fortunately, RC does not have a fixed bud, which allows it more flexibility to grow when conditions are favorable, even in winter. Our tree also had to survive animal devastation. Black bears foraging for food in the early spring can decimate young stands by stripping bark to reach the sweet phleom, and browsing animals consider young cedar foliage a tasty treat. Perhaps hard winters or Native American hunting pressure kept animal numbers low? Fortunately, our tree either avoided or survived these threats.

Unique chemical compounds in RC also make it resistant to many of the insect and disease issues affecting other conifers, giving our tree a big advantage. Additionally, once established and growing, RC produces compounds that make the wood very resistant to decay. But because these substances are not produced until the tree is older, young RC is left with a center that is vulnerable to decay. The aging process also breaks down decay resistance, so extensive decay may be present in very old trees. Although this rot can reduce the tree’s commercial value, it does offer a secondary gain for wildlife because it creates conditions ideal for cavity nesters. So our redcedar became a home to numerous species.

Because our tree is a relatively slow growing species, other trees may have taken over the forest canopy. But western redcedar develops special shade needles that give it a high tolerance to shade, allowing it to continue to grow even under a full forest canopy.

As is true in any forest, our tree faced a continual wildfire threat. Western redcedar foliage is very flammable, the tree has shallow roots, and the bark offers little protection from fire. Fortunately, RC is a very tough tree and can persist even if only a small part of its living tissues (cambium, needles, and roots) survive and remain connected. This incredible tenacity allowed our tree to survive numerous wildfires.

The above characteristics, among others, likely contributed to our RC developing into the Idaho State Champion and largest North American west of the Cascades: a western redcedar 18 feet in diameter and 177 feet tall that is accessible via the paved Giant Cedar National Recreation Trail  on the Nez Perce/Clearwater National Forest. The age of this tree has been speculated at around 3,000 years; however, the age of this old western redcedar must be projected because extensive decay makes accurate tree ring counts impossible. The oldest confirmed western redcedar age is around 1,500 years.

Special management considerations.  Although it is possible to find a few scattered relics, most western redcedar trees on private land in our area are not much older than one hundred years because they became established following soil disturbance by logging or wildfires at the turn of the last century. Of course, there are notable exceptions on public land, such as the majestic Ross Creek Cedars in Montana or Settlers Grove near Prichard, Idaho. All these trees became established under much different disturbance regimes than are happening in today’s forests.

Differing disturbance regimes coupled with the special needs of RC, especially the risk of loss to big game, offer great challenges to perpetuating the species on our private forest lands. And though challenging, management of this spectacular tree can be very rewarding on the proper site.  Here are a few principles to keep in mind:

  • Removing trees from around subordinate RC may release some trees in a mixed-species stand, but keep in mind that partial logging also favors the establishment of other less desirable species, most commonly grand fir in the Inland Northwest. Partial logging may also lead to population decline if stands with redcedar are opened too much. Eliminating the shade in dense stands leaves the trees very susceptible to sun shock. Thinning lightly from below, or not at all, may be an option for such stands. A clumpy harvesting strategy that opens carefully selected areas for reforestation while leaving other patches relatively untouched is another effective strategy.
  • If a regeneration harvest is your objective, understand that once cut, it is very difficult for RC to become established in the new stand because of challenges related to proper site preparation, ungulate browsing, and possibly, the lack of a good seed source. Consider leaving a few old relics or clumps of younger cedar to reseed, if not for the next rotation, possibly for future stands and wildlife habitat.
  • Planting western redcedar comes with high risk. Well maintained protection from big game is a must. Selecting the correct site is also crucial because soil moisture is such a big issue until the seedlings become well-established. And western redcedar is also susceptible to root damage and compaction because of its shallow root system.