Mortality of Bitterbrush after Burning and Clipping in Eastern Oregon

Abstract

Bitterbrush plants were burned or clipped to 5 cm, during fall and spring, under different soil moisture conditions on 2 sites in eastern Oregon. Treated plants on the Juniperus/Artemisia-Purshia site had an erect growth form while those on the Pinus-/Purshia site were a loq-growing, decumbent form. Sprouting after treatment was similar for the 2 sites and associated forms. Burning resulted in greater mortality than clipping. Spring treatments had less mortality compared to fall treatments. Artifically watering plants did not result in a substantial reduction in mortality. Over-winter mortality of sprouts reduced the number of bitterbrush plants alive in the second growing season.