The tree that ate the west! Both native and invasive—protected and reviled—WESTERN JUNIPER (Juniperus occidentalis) are a living contradiction.
Over the past 130 years, changes in land use and management practices have allowed juniper woodlands to expand their geographic range tenfold, profoundly altering the ecosystems they infiltrate.
Beginning around 1870, settlers turned large numbers of cattle loose to eat the native grasses that grew among the sagebrush. This left less fuel for fire, and between this and a widespread campaign to suppress fires across the American West, soon nothing was keeping junipers confined to their steep, rocky sanctuaries.
Given the opportunity, juniper trees outcompete the grasses and shrubs of the sagebrush steppe. In extreme cases, nothing but bare soil and shallow-rooted invasive grasses remain between the trees, dramatically decreasing habitat quality for many species.
The spread of juniper can also reduce water availability in an already-parched landscape. Despite their drought tolerance, a single mature juniper can consume 10 to 30 gallons a day, pulling water from nearby streams and springs. While this affects native wildlife, it’s had an even greater impact on the cattle ranchers who for generations have come to depend on the sagebrush ecosystem’s natural resources. As water and native grasses become scarce, the number of cattle a piece of land can support plummets. Depending on the site and how advanced the juniper growth is, the tree’s invasion can decrease the amount of forage by 30 to 90 percent. The Oregon Cattlemen’s Association has called juniper “one of our most noxious invasive species.”
Numerous agencies have undertaken juniper control projects spanning tens of thousands of acres in Oregon alone, and millions of acres across the West.
Because juniper woodlands decrease the land’s productivity for cattle grazing at the same time that they consume valuable sagebrush wildlife habitat, ranchers are often eager to participate in efforts to control them and Wheeler SWCD is here to assistant!!
[information sourced from freelance writer Rebecca Heisman]