Working Ranch April/May 2025

pasture management BY LORETTA SORENSEN First Things First

or the ranchers or “grass farmers” who call the sagebrush steppe home, hearing that North America’s sagebrush ecosystem is shrinking at what experts say is “an alarming rate,” is less than encouraging. Invaders such as native conifers like western juniper and annual grasses crowd it out, and other serious risks include excess fire or a lack of fire, depending on the location. While many ranchers perceive sagebrush as a woody weed that edges out the grasses they de sire, experts say complete elimination of sagebrush diminishes forage pro duction — which should encourage a look at your management plan. Prioritizing primary threats is the key to grazing in sagebrush country effectively.

Hundreds of plant and animal species call the sagebrush steppe home, and plant species diversity varies dramat ically, with 25 to 50 species inhabiting many sites. Schroeder and Johnson refer to bunchgrasses as “the icebergs of the range. They have most of their resources invested underground, and are the most important func tional group for preventing inva sion by undesirable annual species.” With deep roots, bunchgrasses also improve ecosystem resilience to wildfire, preventing open niches and unoccupied bare ground. If bunchgrasses are lost from sage brush steppe plant communities, annual grasses can quickly take over bare ground, shifting a site to a new state dominated by annual grasses. “This more fire-prone state consists of dense annuals that cure quickly in

ecosystem with a wide variety of plants and animals. “Variation abounds within this complex plant community, over time and space,” they stated. “At different points in the season, fluctuations in temperature and moisture may pro mote the expression of different spe cies of plants. Species also vary across elevation gradients and soil types.”

Vanessa Schroeder, an Oregon State University (OSU) Extension Faculty Research Assistant in the Department of Animal and Rangeland Sciences, and Dustin Johnson, OSU Statewide Rangeland Outreach Coordinator, and Professor, wrote in “Western Roots: Diving into a Sagebrush Sea of Diversity” that a close look at a sagebrush steppe reveals a diverse

ADOBE/BOB

38 I APRIL / MAY 2025 WORKING RANCH audited readers run 21 million head of beef cattle.