The Redwood Experimental Forest at Yurok, California, was established in 1940
to study the silviculture of coast redwood and to develop techniques for regeneration
and management. Redwood is located on the coastal front of the northern coast
ranges in northern California, about 2.4 km inland from the Pacific Ocean and
near the mouth of the Klamath River. The Redwood includes 379 ha drained by
High Prairie Creek. Redwood is the principal forest species on the forest, with
Douglas-fir, Sitka spruce, western hemlock, and Port Orford-cedar making up
the remainder. About 59 percent of the timberland is classified as Site I and
35 percent is classified as Site II. Tree ages range up to 1,200 years. Topography
varies considerably over the forest. Slopes range from 0 to 75+ percent, and
elevation ranges from 40 to 340 m.
About 45 percent of the total area (226 of 502 ha) was clearcut in harvest
units ranging from 1.2 to 62.7 ha between 1956 and 1985. About 1 percent (4
ha) was harvested in 1981 using the selection system. An additional 23 percent
(87 ha) is available for approved manipulative research studies, and 16 percent
(61 ha) is preserved in an undisturbed old-growth redwood forest condition in
the Yurok Research Natural Area (RNA) established in 1976.
Climate
The climate at the Redwood is typically mild and foggy in summer. The average
July temperature is 12.6 °C, with little precipitation other than fog drip.
The average January temperature is 6.8 °C. Annual rainfall averages 1,930
mm and snowfall is uncommon. No climatic data are maintained at Redwood, but
data are available from the town of Klamath, in a similar climatic environment
6 km south and from Crescent City, 27 km north of the forest. Precipitation
is well in excess of potential evapotranspiration, except for about a month
in midsummer.
Soils
The entire region is underlain by Mesozoic rocks of the Franciscan formation,
a complex of raw to slightly metamorphic sedimentary rocks. This formation is
generally soft and easily weathered, so that soil development is good, with
unweathered regolith at depths of about 3 m in most areas. Rock outcrops are
few, and where they do occur, shallow soils and exposure combine to make such
sites ecologically unique. The major soil series is Melbourne, with a small
amount of Hugo series along the ridgetops (about 6.5 ha) and Atwell series at
the lower elevations on the southern part of the Redwood (about 2.0 ha). Unclassified
alluvial soils are found along High Prairie Creek on about 32.4 ha.
Vegetation
The Yurok RNA supports very dense stands of oldgrowth redwood averaging about
200 m2 of basal area per hectare. The two dominant vegetation types on the forest
are redwood-western swordfern and red aldersalmonberry.
Long-Term Data Bases
Timber data on regeneration after cutting, young stand growth and yield, response
to thinning, and redwood sprout development are available (intermittently) between
1956 and 1982. Post-harvest regeneration and effects of shelterwood removal
data were recorded between 1970 and 1985. Soil-vegetation maps are also available.
Wildlife habitat data are available on species composition and abundance of
vertebrate communities in response to changes in age, moisture, and structural
features of forest stands from 1983 to 1985. Fish habitat data describing stream
reaches and distribution of fish species in High Prairie Creek were mapped from
1984 to 1987.
Research, Past and Present
The following topics have been studied:
- salmonid preference for obstacle-formed pools
- stream structure and fish production
- ecology of old-growth forest wildlife habitat community
Facilities
The Redwood is readily accessible from U.S. Highway 101, 27.2 km south of Crescent
City and 6.4 km north of Klamath. Commercial facilities are available in these
communities.
Lat. 41°35´ N, long. 124°5´ W
Contact Information
Redwood Experimental Forest
USDA Forest Service
Pacific Southwest Research Station
Redwood Sciences Laboratory
1700 Bayview Drive
Arcata, CA 95521-6098
Tel: (707) 825-2930
http://www.fs.fed.us/psw/programs/TimberManagement/yurok
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