Western juniper and sagebrush dominated the landscape as we drove along Highway 218 from Antelope to Fossil in eastern Oregon last week. In most cases, juniper trees were surrounded by bare ground.
On one long stretch, dozens of junipers had been cut and laid down like fallen dominoes. A local person told us that junipers used so much water that it reduced grasslands for grazing cattle.
Researchers now have data to prove that junipers are a threat to the ecology by knocking the water system out of balance.
Tim Deboodt, an extension agent for Oregon State University’s Crook County Extension Service, has been studying junipers and working to discover ways to stop the seemingly inexorable march of junipers in semiarid regions.
A 4-foot-tall juniper that is 12 inches in diameter can consume 25 to 35 gallons a day, Deboodt said. The juniper has adapted because of its ability to capture water up to 40 feet from the trunk in all directions through a network of small roots several inches below the ground.
The coniferous trees are native to the region. Fires, both set and natural, kept junipers under control; since fire suppression became a management tool, trees that would have been burned now thrive and spread, dominating the water supply.
“If there are nine to 30 junipers an acre, in theory they could use all the water delivered as rain and snow. A juniper’s canopy is very efficient at capturing snow,” Deboodt said, “holding it until it evaporates so that water never hits the ground. That can be as much as 20 to 40 percent of the annual precipitation.”
Juniper canopies also catch a significant amount of any rainfall before water can run off the trees.
Trapping snow and intercepting water, plus a nearly insatiable thirst, means there is little left for other plants.
“If I believed in reincarnation, I’d want to come back as a juniper tree because, like the coyote, they’re very adaptable.”
The effects of less water are wide-ranging. Where they thrive, junipers can eliminate habitat (mainly sagebrush) for the sage grouse while providing roosting habitat for their predators, Deboodt said.
A lot of the countryside’s grass production could increase three to nine times without junipers, allowing the soil to retain more water, he said.
Since the late 1800s, overgrazing of livestock reduced the grasses that once carried fire, both natural and set, that kept junipers in check.
Now, chain sawing junipers is standing in for fire.
Since 1935, according to the U.S. Forest Service, junipers have increased their coverage from 1 million to 10 million acres in Oregon.
Various ways of whittling away at the problem have been explored. In some areas, chain saws now are the default position, but junipers far outnumbered the chain saws, making it a daunting, if not impossible, challenge.
“We may have to draw a line around the outside (of their current encroachment) and say, no more,” Deboodt said.
Also in the later 1800s, there was a period of cool, wet weather, perfect for juniper seedling germination and establishment. Junipers prefer to grow for years in the shade under a nurse bush, such as sagebrush and rabbit brush, that also provides a windbreak.
“It’s also ungrateful. When it tops the sagebrush, it can compete for water and eventually kills the plant that protected it. As an area loses the ground cover, erosion rates grow as the surface runoff flows overland rather than sinks into the soil,” Deboodt said.
On the upside, juniper wood makes a hot fire, great fence posts, landscape timbers and beautiful gnarled wood for artists.
Columnist Sharon Wootton can be reached at 360-468-3964 or www.songandword.com.
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