Pacific Northwest Research Station

South Umpqua Experimental Forest

Introduction

The South Umpqua Experimental Forest was established on the Umpqua National Forest in 1951. It was originally intended to provide research opportunities in the mixed-evergreen forest type common in the Cascade Range of southern Oregon. Experimental watershed studies were undertaken on four watersheds tributary to Coyote Creek by researchers in Corvallis in 1962. In 1967, the area of the forest was reduced in total area from the original 1,921 to 263 ha of the Coyote Creek experimental watersheds.

Climate

Annual precipitation at the watershed #2 gauge from 1961 to 1976 averaged 1,230 mm and ranged from 880 to 1,560 mm, falling mainly as rain but with some snow in winter. During this period, annual discharge from the control watershed averaged 630 mm.

Soils

Soils in the South Umpqua are derived from volcaniclastic bedrock and are moderately well-drained gravelly loams to a depth of 150 cm. Both active and inactive large, slow-moving landslides have created subdued topography in parts of the area, especially watershed 3.

Vegetation

The forest vegetation of the South Umpqua is characteristic of the mixed-conifer zone with Douglas-fir intermingled with several pine species, incense-cedar, other conifers, and several hardwood species.

Long-Term Data Bases

Streamflow and climate records for the Coyote Creek watersheds are available online from the Forest Science Data Bank associated with the Corvallis Forestry Sciences Lab (http://www.fsl.orst.edu/lter).

Research, Past and Present

The Coyote Creek experimental watershed studies of the effects of cutting and regrowth on hydrology and sediment production have been the central feature of research on the South Umpqua. After gauging commenced in 1962, watershed treatments were implemented in 1971, involving roads constructed in watersheds 1, 2, and 3; watershed 1 was partially cut, watershed 2 had small patches cut, watershed 3 was clearcut and burned, and watershed 4 was left as a control. Stream gauging and other studies were ended in 1981 but were restarted in 2000-01 in a cooperative effort of the Umpqua National Forest and Pacific Northwest Research Station. A few studies of sediment production, ecology of mixed evergreen forest types, and effects of forest cutting and regrowth on streamflow took place in the Coyote Creek experimental watersheds in the early study period. The new period of stream gauging and sediment basin monitoring is intended to set the stage for thinning and perhaps prescribed fire in the South Umpqua in the near future.

Facilities

The South Umpqua is located on the Umpqua National Forest’s Tiller Ranger District west of Tiller, Oregon, in the South Umpqua River drainage. The forest has no facilities (other than roads, gauging stations, and sediment basins) nor a web page, except for watershed research data on the Andrews Experimental Forest web page (http://www.fsl.orst.edu/lter). The area is accessible via the National Forest System roads.
Lat. 43° 1' N, long. 123° 10' W

Contact Information

South Umpqua Experimental Forest
USDA Forest Service
Pacific Northwest Research Station
Corvallis Forestry Sciences Laboratory
3200 SW Jefferson Way
Corvallis, OR 97331
Tel: (541) 750-7355
http://www.fs.fed.us/pnw/exforests/south-umpqua/index.shtml

¹Information has been updated since original publication.

pnw > exforests > South Umpqua