How Fire Saves Water

[EDITOR’S NOTE: Fall term, Braelei Hardt participated in a field trip to Oregon’s high desert with other students from the University Honors College. This article is based on her experiences in the “Oregon outback.”]

Braelei Hardt (far right) explores Oregon's high desert with Honors College classmates Arthur To, Anantnoor Kaur, Lindsey Almarode. (Photo: Lindsey Almarode)

Parts of the Oregon outback are a poetic juxtaposition of passionate color scattered among charred, stalagmitic trees piercing the sky above like mighty javelins. In autumn, the understory blazes in hues of red, orange and yellow — colors that light the burnt forest as if it were once again on fire.

This scene in Central Oregon near the town of Sisters, where the Black Butte II fire of 2009 torched 630 acres of timber, may seem upsetting. But is fire only a force of terror?

John Buckhouse of the Institute of Water and Watersheds at Oregon State University says, avidly, “No!”

As a hydrologist, Buckhouse may seem like the wrong kind of expert to comment on the affairs of fire. He has, however, been studying the interconnecting effects of fire, water, and vegetation on Oregon’s rangeland ecology for years.

Buckhouse says fire is a critical element in retaining a healthy outback — and for a good reason, too. Fire has been part of Oregon’s natural cycle for thousands of years, and the land in turn has evolved to accommodate and even depend on fire. It used to ravage the area every seven to 15 years, keeping large trees like Ponderosa pines in check and burning off dead matter that would otherwise steal life-giving sun from the active plants underneath it. Lodgepole pines actually depend on fire to reproduce, for their cones only release seeds in the heat of flame.

Since the development of effective firefighting techniques, concerned citizens looking to “save” the environment have disrupted this cycle and thrown the natural order of things out of balance, according to Buckhouse. The wildly adverse effects of this intervention are just recently coming to light, he says. The worst of these involve the western juniper tree.

Buckhouse’s longtime friend and colleague Hugh Barrett has been assessing juniper in Oregon’s high desert for eight years. He explains that before firefighting, fires would keep the juniper in balance with other desert-dwelling plants. Now, without the natural fire cycle, the trees have overtaken the land.

Most desert plants conserve energy by going into dormancy during the winter. All processes, including water use, come to a halt. This allows water from winter downpours and snowstorms to seep into the ground, where it is stored until spring when the land once again returns to life.

Juniper, however, does not go dormant. This creates a huge problem when there are too many juniper trees in one area. “Usually, you would see maybe four or five old junipers in an open expanse,” Barrett explains. “Now there are maybe 20. These large trees pump 25 to 30 pounds of water out of the soil per day.” This quickly depletes the desert’s winter water reserves, leaving smaller bunchgrasses to literally die of thirst. This is extremely evident when standing next to an old juniper, for there are no shrubs at all in a 30-foot radius around the tree.

The water-sucking junipers also cause even more advanced ecological problems. The increase in tall trees provides more perches for birds of prey. With more birds of prey, there are fewer ground mammals to disperse seeds, further diminishing the brush population.

Barrett notes that in areas without junipers, bitterbrush (named for its bitter taste) grows waist high in approximately nine months. In the land’s current state, it takes five years.

Braelei Hardt atop a rock formation in the high desert. (Photo:Caity Clark)

Why are these shrubs and grasses so important? The answer comes down to water retention. For a system’s watershed to be healthy, Barrett says, it must preserve three aspects: capture, hold, and safe release. The brush in Oregon’s outback contributes to the first aspect. “It’s like arm hair,” Buckhouse explains quirkily. “The arm is the land, and the hair is the brush. If you run water over a shaved arm, like a swimmer’s arm, the water rolls off quickly. But if you have hair, the water will trickle down, curving around the obstacles, and will have more time to soak in.” More time to soak in means greater water retention and a larger storage. Without sagebrush, bitterbrush, and bunchgrasses, the water simply rolls off the land and cannot be captured.

Buckhouse and Barrett are working on a plan to reintroduce flame into the desert in the form of controlled burns, which will burn off the parasitic junipers and restore these critical shrubs. This is how fire will save water — and how the high desert may return to its former glory.

Controlled burns would not only revive the environment but also yield economic gain, Buckhouse and Barrett stress. The Ponderosa pines and juniper trees have grown so large that many of them would need to be topped for the burn to work effectively. The remains could be chipped or sold to paper companies.

Barrett, like a docile bear, lumbers toward a massive juniper and rests his hand upon it. “We shouldn’t see the world as it is,” he says, “but as it can be.”