MAPPING CEDAR DIEBACK
An Iconic Northwest Tree in Trouble ! Help Scientists Gather Data and Develop Solutions
B y N i a l l D u n n e
Western red cedar , Thuja plicata , is the iconic tree species of the Pacific Northwest . The beautiful , big conifer — with its pyramidal form ; gray-red , fibrous bark ; and glossy , scale-like leaves — is a critically important component of our region ’ s Native American cultural heritage , industrial heritage , and forest ecology .
Indigenous peoples use all parts of the tree for housing , basketry , furniture , clothing , fuel , medicine and more . With its light , diseaseresistant wood , western red cedar has played a pivotal role in our region ’ s forestry economy . A common tree in drainages and riparian systems throughout the forests of the Northwest , the species provides a range of critical ecological services , including soil stabilization , nutrient cycling , carbon sequestration , and temperature regulation of salmon-bearing streams . It ’ s also an important component of our urban canopy — for example , about 1500 western red cedars are listed in Seattle ’ s street tree dataset alone .
However , like several other of our native tree species — including western hemlock ( Tsuga heterophylla ) and bigleaf maple ( Acer macrophyllum )— western red cedar appears to be in trouble . In the past few years , there have been widespread reports of dieback throughout the tree ’ s range ( Northern California to Alaska , west to Montana ). Mapping by the U . S . Forest Service ’ s Aerial Survey has confirmed that the dieback is widespread .
Summer 2021 v 7