JOINT BASE LEWIS-McCHORD, Wash. – Joint Base Lewis-McChord is full of beautiful forests. Often, the forests are filled with Douglas fir trees, but ponderosa pine is also present. Ponderosa pine is more commonly found east of the Cascade Mountains and is rare in western Washington.
In late spring 2022, JBLM’s Directorate of Public Works Forestry team first noticed damage to ponderosa pine trees in the training lands. The trees were dying from the top down, with red-brown needles at the top and green needles near the base of the tree.
In July 2022, entomologists from the United States Forest Service and the Washington Department of Natural Resources visited JBLM and confirmed the cause was a bark beetle named the California five-spined Ips (Ips paraconfusus) beetle, commonly referred to as the Ips beetle.
The Ips beetle only attacks pine species and usually prefers diseased, stressed or small pine trees. They breed in fresh pine slash, which is made from woody material that accumulates through logging, wind, snow or other natural disturbances.
Ips beetles burrow under the bark and kill the tree from the inner bark. Sometimes, boring dust is visible on the outer bark of the tree. These beetles can kill a tree in just a few months, so actively managing affected forests is very important.
“Ponderosa pine is so uncommon on the west side of the Cascades that we feel a special obligation to protect and maintain these trees on JBLM,” said Kathryn Hill, JBLM DPW Forest and Fire ecologist. “Especially considering their adjacency and overlap with the native grasslands and oak woodlands of the South Sound. We prudently apply prescribed fire to keep these stands healthy and well-thinned, which helps buffer them from future beetle attacks.”
Currently, the Ips beetle outbreak on JBLM is contained in two small patches of pine. Both patches are hard to manage because of access, high fuel loads and snag presence, so prescribed fire management is inconsistent. Although the DPW Forestry team observed some scattered individual pines with damage, no other outbreaks are known.
JBLM has approximately 4,700 acres that contain ponderosa pine, but only about 850 acres are pine-dominant. About 90 percent of these lands are actively managed with prescribed fire and other techniques by the DPW Forestry team.
The land is managed to keep fuel loads low, keep stands well-thinned and consume debris that could provide breeding habitat for the beetle. Actively managing these lands reduces the overall risk from the beetle to JBLM forests.
During a media visit in May 2024, visiting entomologists’ preliminary assessment was that the beetle appeared to have run its course within damaged stands and the outbreak was likely to be dying down. With the help of the DPW Forestry team and visiting entomologists, JBLM can control and keep the outbreak to a minimum.
Anyone who notices ponderosa pine trees that look like they are dying at the top and healthy at the bottom, or observe boring dust, is encouraged to report the information to the DPW Forestry team by email at usarmy.jblm.id-readiness.list.dpw-enrd-forestry1@army.mil.
Social Sharing