|France, Kevin - OREGON STATE UNIV|
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 20, 2004
Publication Date: February 1, 2005
Citation: France, K., Boyd, C.S., Ganskopp, D.C. 2005. Interspace/under-canopy foraging patterns of beef cattle in sagebrush communities. Society for Range Management Meeting Abstracts. No. 113 Technical Abstract: Livestock grazing has been indirectly related to sage grouse declines in the western United States and southern Canada; however, there is a lack of scientific research that directly relates the two. An 18-day trial was conducted to determine the level of utilization at which cattle begin to access herbaceous vegetation under the canopy of sagebrush plants. This vegetation provides important cover for sage grouse nesting habitat. Four pastures were fenced in a Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) community ranging in size from 6.1 to 6.5 ha and 4 yearling heifers (avg. 385 kg) were stocked in each pasture. Within each pasture 30 sagebrush plants were randomly selected and a perennial grass was permanently marked under the canopy of each sagebrush and in the inter-space. Area and volume of the sagebrush were measured and the angle of accessibility was measured for the under-canopy grass to assess the effects of sagebrush morphology on grazing occurrence. Grass plants were checked every second day and given a grazed or ungrazed score. Changes in standing crop and utilization (by weight) were assessed weekly by clipping 20 random 1m² plots in each pasture. The location by day interaction was significant (p=0.0001). Grazing of under-canopy plants was negligible at light to moderate levels of utilization (e.g. < 10% of under canopy plants have been grazed at 30% pasture utilization). At utilization levels >30%, under canopy plants were used with increasing frequency.