Fire and community diversity in the western juniper/sagebrush steppe mosaic

Publication Type:

Magazine Article

Authors:

Bunting, Stephen

Source:

Sage Notes, Idaho Native Plant Society, Volume 23, Issue 2, p.1-3 (2001)

Call Number:

U01BUN01IDUS

Abstract:

Western juniper woodlands occupy eight million acres in southeastern Idaho, eastern Oregon, northwestern Nevada, and northeastern California. They typically occur in a sagebrush steppe mosaic that is dominated by mountain big sagebrush (Artemisia tridentata ssp. vaseyana), Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), and low sagebrush (Artemisia arbuscula), as well as aspen (Populus tremuloides) and other vegetation. Like other types of juniper and pinyon-juniper woodlands found in the Intermountain West, western juniper woodland has encroached into sagebrush steppe during the past 150 years. Our research on the Owyhee Plateau indicates that the area occupied by the various successional stages of juniper woodland has approximately doubled in the past 150 years, increasing from about 40 to 80% of the area of the watersheds studied. Other studies have indicated that encroachment rates were highest during the late 19th and early 20th centuries, but encroachment continues today. During this period the density of juniper has increased in communities where it was formerly found, and juniper has expanded its distribution into adjacent vegetation types as well. This encroachment has affected species and community diversity in many of these landscapes.