Juniper Thinning

All along the banks of the Chewaucan we saw juniper trees sawn down, laying dry and brown on their sides. It's part of a controversial project to return the high desert to its normal state.

Western junipers are native to the High Desert, but prior to the late 1800s only an occasional tree dotted the landscape, said Rick Miller, an OSU professor who studies junipers.

The trees can live to be more than 1,000 years old. They start off life slowly, spending the first 20 years putting energy into their root systems, before undergoing a growth spurt between ages 45 and 80 or 90, Miller said. He has sampled a tree that started growing in 100 B.C. and died about 400 years ago.

Juniper trees have been in Oregon for between the last 4,000 to 6,000 years, he said, “but it’s just filling in because of changes in land use ... We don’t think it’s ever reached the abundance it is today, it really is an unprecedented change.”

The change in Central Oregon began in the 1880s, when cattle and sheep ranchers began grazing huge numbers of livestock on the land, he said. Grazing fireproofed the landscape by removing the grasses and brush that fuel periodic fires, and the junipers proliferated without burns to keep them in check. This effect was amplified after World War II, Miller said, when firefighters ramped up fire suppression efforts in the region.

There were about 450,000 acres of western juniper in Oregon in the mid-1930s, but the trees now cover 6 million acres, said Tim Deboodt, an OSU extension agent in Crook County and co-leader of the watershed study.

And junipers use up a lot of water. On a warm day, a 12-inch diameter tree can suck up 50 gallons of water, Deboodt said. If there are nine to 15 trees of that size on an acre of land that gets 12 inches of precipitation a year, they could use all of it, he said.

More in the Bend Bulletin.

Update: Greg adds this article from the OSU Agricultural Experiment Station newsletter.