A Blaze’s Benefits
Published 7:30 am Saturday, June 1, 2019
- Jayson Jacoby/Baker City HeraldForest Service officials Willy Crippen, left, and Kendall Cikanek discuss the benefits of a prescribed fire that the agency ignited on May 10 in Washington Gulch, about 4 miles west of Baker City. A group of officials toured the burned area on Tuesday.
Willy Crippen is standing in a patch of black ground, a couple of hip-high, red-needled ponderosa pines to one side and to the other a swath of bright green grass interspersed with the yellow blooms of heartleaf arnica.
It’s the sort of colorful spring forest scene that inspires a painter or a poet.
But it’s not this varied palette that brought Crippen and a group of Forest Service officials — and one from Baker City Hall — to Washington Gulch, about 4 miles west of town, on this sunny but blustery day after Memorial Day.
Indeed their visit has as much to do with a scent as it does with a sight.
The rich aroma of woodsmoke lingers here among the pines, conjuring images of campouts and the roasting of hot dogs and marshmallows.
But the fire that burned through here 18 days earlier had a more far-reaching purpose than toasting something tasty.
This 225-acre blaze — what the Forest Service calls a prescribed fire — had multiple goals. Chief among them was to consume, in a controlled way, some of the trees, logs, pine needles and other combustible stuff that could have fueled a much larger blaze on a torrid summer afternoon.
The sort of fire that could cost millions to fight and still keep growing until it’s doused with rain.
This location in the foothills of the Elkhorns explains the presence of the lone Baker City representative among the half dozen Forest Service employees.
Michelle Owen is the city’s public works director.
Owen is here to see firsthand the Forest Service’s efforts to reduce the risk of a wildfire spreading uphill from here to the city’s 10,000-acre watershed, its boundary little more than a mile away.
City officials have worried for decades that a big blaze in the watershed would foul with ash and mud the streams and springs that supply almost all the city’s water.
Such a fire could force the city to find a temporary replacement water source, and spend more an estimated $10 million to $15 million to build a plant to filter water from those streams.
“Anything we can do to protect the watershed,” Owen said as the group looked across the forest.
Crippen, a fire management officer for the Forest Service’s Whitman Ranger District, said the agency’s long-term strategy, which includes thinning the forest, piling and burning slash and then, as happened in Washington Gulch on May 10, igniting a prescribed fire, creates areas where a summer blaze sparked by lightning or a carelessly discarded cigarette would be easier for fire crews to stop.
The Forest Service has focused on the Washington Gulch area over the past decade and a half not only because of its proximity to the watershed.
The area also borders private land that includes many homes in the strip where the Baker Valley gives way to the Elkhorns — a zone that fire experts call the “wildland-urban interface.”
Curbing the wildfire risk in this area not only helps protect the watershed from flames moving uphill, Crippen said, but it can serve as a buffer between a fire that starts higher in the mountains and then moves down onto private property.
Forest Service projects in and around Washington Gulch date to about 2002, said Steve Hawkins, deputy fire staff fuels program manager for the Wallowa-Whitman National Forest.
The area is rather typical of lower-elevation sites in the Elkhorns, he said. Based on historic photos and written accounts dating to the late 19th century, Forest Service officials know that forests in many areas then were dominated by old growth ponderosa pines in what Hawkins describes as a “park-like stand.”
That basically means there was considerable open space around most trees — often 30 feet or more — with relatively little underbrush and few young trees.
Hawkins said these forests were maintained in that condition by lightning-sparked blazes that swept through every decade or so on average. These blazes mainly stayed on the ground, scorching the layer of pine needles, limbs and twigs, and preventing younger trees from growing tall enough to serve as “ladder fuels” — a route by which flames can climb from the ground into the crowns of mature trees.
But the situation changed dramatically during the 20th century. The combination of logging that removed most of the mature pines, and the Forest Service aggressively fighting fires, allowed younger trees to proliferate.
This “new” forest was much more dense, Hawkins said. In addition, Douglas-fir and grand fir trees — species more susceptible to fire and to insects — were much more common than in the past, he said.
Returning these forests to something closer to their historic condition is a long process with multiple steps, Hawkins said.
In Washington Gulch the Forest Service has over the past 15 years or so employed commercial logging, “precommercial thinning” — basically, cutting and piling trees too small to be sawed into boards — and prescribed fire.
The logging and thinning were done first because the forests were so dense that even a managed fire, ignited during spring when the ground is still damp and temperatures not yet at summer levels, would burn too hot and likely kill more of the mature trees than Forest Service officials prefer, Hawkins said.
Even if the flames don’t spread into tree crowns the intense heat can damage the cambium layer beneath their bark and doom the trees, said Kendall Cikanek, the Whitman District ranger.
During Tuesday’s tour, Hawkins, Crippen and Cikanek pointed out several examples of how the May 10 prescribed fire accomplished some of the agency’s goals.
They looked at patches where flames scorched most of the young pines and firs — generally shorter than 5 feet.
In those areas the blaze likely mimicked those lightning fires of the past, Hawkins said, killing fledgling trees before they could become tall enough to become ladder fuel.
The May 10 fire also spread into the crowns of scattered older, taller trees.
Although some of those trees likely will survive despite their currently red needles, Crippen said Forest Service standards allow for up to 10% mortality even among mature trees — the Washington Gulch fire was well below that level.
When a prescribed fire kills mature trees it makes openings in the canopy, a natural component of a healthy forest, as well as creating standing dead trees — “snags” — that serve as habitat for woodpeckers and other wildlife, Crippen said.
The most distinctive feature of the May 10 fire, though, is its patchy nature.
The predominant color within the burned area is the rich green of pine grass, some of which has already resprouted from the black splotches, many of them 20 feet or less in diameter, that litter the landscape.
Indeed, Hawkins estimated that the May 10 fire accomplished only about half of what Forest Service officials hoped, in terms of consuming fuel, both ground litter and live trees.
That’s typical of prescribed burns during the spring, he said. The abundance of green foliage, and the damp ground and relatively high humidity, prevents flames from spreading as rapidly as they would during summer.
(This, of course, also explains why prescribed burns are lit during spring or, occasionally, in fall.)
Generally speaking the fire left what foresters call a “mosaic” — a mixture of burned and unburned areas.
“I like what I see here,” Cikanek said.
“It burned where there was fuel on the ground, which is where you want it to burn,” Hawkins said.
If possible, the Forest Service will try to ignite another prescribed in this area within several years.
See more in the May 31, 2019, issue of the Baker City Herald.