LARAMIE, Wyo. (AP) – A research project underway at Pole Mountain Work Center in the Medicine Bow National Forest might help slow the spread of white pine blister rust, which is killing trees across the West.
As part of the Southern Rockies Rust Resistance Trial, more than 700 limber pine and bristlecone pine seedlings were planted at the work center in August.
Some of the trees were selected because they have resistance to the disease, while others are thought to be susceptible.
They’ll all be exposed to white pine blister rust in hopes that the resistant ones will prove their immunity outside a laboratory setting, paving the way for growing more.
“It’s very critical for future management of different species of white pines,” Laramie Ranger District forester Sara Alberts said.
White pine blister rust is a non-native pathogen that came to North America from Asia. It affects members of the five-needle pine group, also called white pines, which include limber pine and bristlecone pine. In northwest Wyoming, the rust affects whitebark pine, a critical food source for grizzly bears that is especially threatened.
The disease has spread to 38 states and has been found in the Pole Mountain area for the last 20 years.
“It’s pretty much everywhere,” Alberts told the Laramie Boomerang. “It’s probably not quite as bad on Pole Mountain as some places, but it’s a moderate level.”
The disease moves back and forth between pines and nearby gooseberry or currant plants. The first symptom of infection on a pine may be a small yellow or red spot on a needle. Eventually the infection moves to the branches, and then the stem. The infection will eventually girdle the stem and kill the tree.
Alberts said it can kill smaller trees quickly but takes longer in larger trees.
“In the Pole Mountain area, you’ll see limber pine with a dead top or dead branches, or the outside half of the branch is dead. That’s commonly how we see it here,” she said. “It will take a very long time to actually kill a large tree.”
Research conducted by the U.S. Forest Service found that some trees have resistance. The goal of the Southern Rockies Trial is to see if those trees demonstrate the same resistance in a natural environment.
“In a controlled environment, they could act differently. This is intended to put them out in a real-life scenario,” Alberts said.
The seedlings were planted at the Colorado State Forest Nursery in Fort Collins last winter.
Alberts said researchers are hoping to have some idea whether the trial is successful within a couple years.
Another batch of seedlings will be planted next spring, and the trial itself is expected to continue for at least another five years. Trees that show resistance will be planted throughout the Rocky Mountains, both in places already infected and in healthy stands.
“Our goal is to increase the health and resilience of Southern Rockies high-elevation pine populations, as well as their ecosystems,” said Anna Schoettle, a research plant ecophysiologist with the Rocky Mountain Research Station.
The project is a joint effort between the Medicine Bow National Forest, the Forest Service’s Rocky Mountain Research Station, Colorado State University and the Forest Service’s Forest Health Protection Program. Most of the funding was provided by the USFS Rocky Mountain Regional Office in Golden.
The Pole Mountain Work Center sits east of Laramie near Interstate 80. It was originally used by the Civilian Conservation Corps and the Forest Service in the 1930s for high-altitude reforestation projects.
“It’s a really cool project that we’ve been excited to be involved with and hosting,” Alberts said. “It’s for a future cause.”
