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Vegetation

Uplands in the Deschutes Basin

The word "uplands" is used to describe the higher-elevation areas between river and stream valleys. These areas tend to have drier soils than surrounding lowland, or valley bottom areas. In areas like the Crooked River drainage, the uplands are highly dissected, or separated into crevices and gorges by erosion, and have steep slopes.

The plant communities of the Deschutes uplands vary widely with elevation and precipitation. Vegetation ranges from from hemlock and alpine forests in the upper elevations of the Cascades and Ochoco Mountains, to sagebrush shrublands in the uplands of the middle and lower basin.

The uplands of the Deschutes River Basin play an important role in delivering water to the lowland areas and rivers. Snow that falls in the mountains of the uplands melt in the spring and flow down to form the headwaters of rivers such as the Deschutes, the Metolius, and the Crooked. The water held in these rivers and their tributaries support vast populations of wildlife, fish, and plant life, as well as provide irrigation water for crops and livestock. In the Deschutes Basin, the uplands and lowlands are inextricably linked.

Juniper and Sagebrush

Much of the uplands in the central and eastern parts of the Deschutes Basin are covered by sagebrush grasslands and western juniper woodlands. The sagebrush grasslands have an overstory of sagebrush and other shrubs such as bitterbrush, rabbit brush, and mountain mahogany, and an understory of perennial bunch grasses and forbs. Western juniper is a long- lived conifer that can survive with as little as eight inches of annual precipitation. Young juniper can occur intermixed with sagebrush and other shrubs and grasses. However, as a stand matures, closely-grouped junipers grow above and shade out understory vegetation.

Before European settlement, fire helped maintain the distribution of these plant communities. Juniper, a species intolerant of fire, was largely restricted to areas with shallow soils and little understory vegetation that could carry flames. In contrast, the shrubs and grasses of the sagebrush steppe were adapted to fire and could quickly reestablish themselves after periodic burns. But fire suppression by humans has led to a dramatic change in the distribution of the vegetation in these two habitat types. Since European settlement there has been a 70% increase in juniper woodland acreage in the Deschutes Basin, with most of this expansion displacing sagebrush shrublands. Extensive juniper removal and control efforts are underway in the Deschutes Basin as well as other parts of central Oregon.

One species particularly affected by the loss of sagebrush habitat is the greater sage grouse (Centrocercus urophasiansu). This large, chicken-like bird feeds on sagebrush and requires stands of open sagebrush for its unique mating display. Greater sage grouse numbers are declining, and in 2008 the U.S. Fish and Wildlife Service began considering protecting the species under the Endangered Species Act.

Sagebrush Restoration and Management Sources

Sagebrush Cooperative. Collaboration between public agencies, nonprofits and landowners. Works to identify strategies and priorities for successful conservation of sagebrush steppe ecosystems in the high desert of Oregon, Idaho and Nevada.

SAGEMAP. A GIS Database for Sage-grouse and Shrubsteppe Management in the Intermountain West maintained by the U.S. Geological Survey.

Sagebrush Steppe Treatment Evaluation Project (SageSTEP) - A network of twenty sites in six states where researchers are testing ways to combat cheatgrass and reduce woody plant encroachment in sagebrush ecosystems.

Juniper Encroachment Sources

Biology, Ecology and Management of Western Juniper. Technical Bulletin 152, Oregon State University/Agricultural Experiment Station, June 2005.

Harney County Watershed Council. (2007). The quiet invasion : Managing juniper in eastern Oregon. Corvallis, OR: Forestry Media Center, 2007.

Western Juniper Field Guide: Asking the Right Questions to Select Appropriate Management Actions. Miller, R., Bates, J.P., Svejcar, A.J., Pierson Jr, F.B., Eddleman, L. 2007. United States Geological Survey Circular 1321, 61p.

Northwest Power and Conservation Council Deschutes Subbasin Plan, Appendix III - Wildlife Assessment. Analysis of changes in habitat distribution in the Deschutes Basin and discussion of issues surrounding key wildlife species including sage grouse.

Authored by Maria Wright, Faculty Research Assistant, Institute for Natural Resources and Caitlin Bell, Staff, Oregon Explorer