Berg, Neil H.,tech. coord. 1990. Experimental forests and ranges. Field research facilities of the Pacific 

Southwest Research Station. Gen. Tech. Rep. PSW-119. Berkeley,CA: Pacific Southwest Researchstation, 

Forest Service, U.S. Department of Agriculture; 67 p. 

The 10 experimental forests and ranges in California administered by the Pacific Southwest Research 

Station, Forest Service, U.S. Department of Agriculture, are described. The purposes of these facilities, and 

how to request their use for approved scientific study are given, and the natural resource base, data bases, 

studies, and general features of each are also described. 

Retrieval Terms: forestry, forestry research, wildland research, experimental forests and ranges, California, 

Pacific Southwest Research Station 

The Authors: 

The authors are all Station staff scientists. Most of these individuals have day-to-day administrative authority 

for the experimental forests and ranges described. 

EARL B. ANDERSON, Research Physical Scientist, Riverside (retired) 

NEIL H. BERG, Supervisory Hydrologist and Project Leader, Berkeley 

JOHN G. KIE, Supervisory Research Wildlife Biologist, Fresno 

ROBERT J. LAACKE, Supervisory Research Forester, Redding 

BARRY R. NOON, Supervisory Research Wildlife Biologist and Project Leader, Arcata 

WILLIAM W. OLIVER, Supervisory Research Forester and Project Leader, Redding 

WADE G. WELLS 11, Hydrologist, Riverside 

Publisher: 

Pacific Southwest Research Station 

P.O. Box 245 

Berkeley, California 94701 

April 1990 
Experimental Forests and Ranges 

of the Pacific Southwest 

Research Station 

Neil H. Berg, Technical Coordinator 

Contents 

Introduction..............................................................................................................1 


Blacks Mountain Experimental Forest ..................................................................5 


William W. Oliver 

Challenge Experimental Forest ............................................................................11 


William W. Oliver 

North Mountain Experimental Area ....................................................................17 


Earl B. Anderson 

Onion Creek Experimental Forest .......................................................................25 


Neil H. Berg 

San Dimas Experimental Forest ...........................................................................29 


Wade G. WellsII 


San Joaquin Experimental Range ........................................................................39 


John G. Kie 

Stanislaus-Tuolumne Experimental Forest .............:...........................................45 


William W. Oliver 

Swain Mountain Experimental Forest .................................................................51 


Robert J. Laacke 

Teakettle Creek Experimental Forest ..................................................................57 


Neil H. Berg 

Yurok Redwood Experimental Forest .................................................................63 


Barry R. Noon 

References ...............................................................................................................66 


Appendix-Metric Conversion Table ..................................................................67 


USDA Forest Service General Technical Report PSW-119, 1990. 
* Station Headquarters 

1Station Laboratories 

@ Yurok Redwood Experimental Forest 

@ Blacks Mountain Experimental Forest 

@ Swain Mountain Experimental Forest 

@ Challenge Experimental Forest 

@ Onion Creek Experimental Forest 

@ Stanislaus-Tuolumne Experimental Forest 

@I San Joaquin Experimental Range 

@ Teakettle Creek Experimental Forest 

1San Dimas Experimental Forest 

@ North Mountain Experimental Area 

USDA ForestServiceGeneral Technical Report PSW-119. 1990, 
INTRODUCTION 


The Pacific Southwest Research Station administers 10 experimental forests and 

ranges in California (see map opposite). Experimental forests and ranges are established by the Chief of the Forest Service, U.S. Department of Agriculture, to 

provide outdoor laboratories and to serve as sites for pilot testing and demonstrating integrated management techniques (USDA Forest Serv. 1985). They are 

suitable for short-term studies and are especially useful for long-term studies where 

close control of land management activities and experimental conditions are 

needed. 

Current levels of research activity vary from high (Swain Mountain and San 

Dimas) to low (Blacks Mountain, Stanislaus-Tuolumne, and North Mountain). In 

most cases, the activity is limited to maintenance and monitoring of existing 

studies and installation of a few new ones. Timber is routinely harvested only at 

Swain Mountain and Blacks Mountain, and periodically at Yurok Redwood 

Experimental Forest. San Joaquin is grazed by cattle. North Mountain Experimental Area is under the jurisdiction of the Bureau of Land Management, U.S. Department of the Interior. 

The Station Director has responsibility for planning and executing research on 

experimental forests and ranges and for determining if any proposed uses are compatible with the research objectives (USDA Forest Service 1987). Coordination of 

activities is generally assigned to a specified project leader of a research work unit 

associated with key research activities on the experimental forest or range. The 

Regional Forester, Pacific Southwest Region, in most cases, has primary responsibility to protect the area and to develop and maintain improvements that serve the 

needs of the general public. Normally, this responsibility is delegated to the 

Supervisor of the local National Forest. 

USDA Forest Service General Technical Report PSW-119. 1990. 
INTRODUCTION 

These experimental forests and ranges are available to scientists from the 

Forest Service and cooperating institutions for conducting manipulative and nonmanipulative research studies. The location and cover type of each experimental 

forest and range are summarized in table 1,and major features are described in the 

following sections of this report. Included for each forest are subsections on 

Climate, Soils, Main Communities, Data Bases, Examples of Research, and 

Facilities. Information on using the forests and on current research is available 

from the contact listed near the end of each section, or from the Station Director in 

Berkeley. A study plan that outlines study objectives, procedures, resource 

commitments, and duration-along with maps of study locations-will ordinarily 

need approval by the designated project leader and review by the local National 

Forest Supervisor before new work can begin. 

USDA Forest Setvice General Technical Report PSW-119, 1990, 

-- 

Blacks Mountain Experimental Forest 

f To Little Va lieu 

uEntrance ' 

-

I To A Cone Mountain 

el.2027m 

LEGEND I 

- -- Gravel or Dirt Roads 

t^ 

-

Mountain or Peak 

0 1I2 

-

1 mile 

0 112 1 kilometer 

USDA Forest Service General Technical Report PSW-119. 1990. 
BLACKS MOUNTAIN 


Experimental Forest 


The Blacks Mountain Experimental Forest was formally designated in 1934 as the 

Station's principal site for management studies in the interior ponderosa pine 

(Pinus ponderosa Dougl. ex Laws. var. ponderosa) type. Studies going back as far 

as 1910 had resulted in new theories of management, silviculture, and insect 

control. A primary objective of the Experimental Forest was to develop these 

theories into a system of management and to test, demonstrate, and improve the 

system through continuous operation of a timber tract on a commercial scale. 

Before full scale operations began, the approximately 4200-hectare forest was 

subdivided into 100 compartments of about 40 hectares each. An intensive road 

system, the first in the West specifically designed for truck hauling, was laid out 

such that every compartment was bordered by a road. Compartments and roads 

have been continuously maintained. 

Early timber harvests were primarily for insect control. An insect risk-rating 

system developed at Blacks Mountain was tested (Salmon and Bongberg 1942). 

When it was demonstrated that the average cut of 35 cubic meters per hectare 

could be logged economically, and that the cutting reduced the annual rate of tree 

killing, sanitation-salvage was adopted widely. Duncan Dunning proposed the 

mosaic of small even-aged groups of trees (the prevailing stand structure at Blacks 

Mountain) rather than individual trees as the subject for management (Hallin 

1954). This concept of "unit area control" was tested operationally during the 

1950's. More recent cuttings have been designed to convert large areas of the 

forest to young-growth stands needed for future research. Today, the forest 

includes a wide range of stand structures and age classes from young plantations to 

old-growth stands (fig. 1)in five uncut compartments designated Research Natural 

Areas. 

USDA Forest Service General Technical Report PSW-119. 1990. 
BLACKS MOUNTAIN Experimental Forest 

CLIMATE 

The climate is characterized by warm, dry summers and cold, wet winters. 

Annual precipitation, mostly snow, for the period 1935 to 1953 varied from 229 to 

737 millimeters and averaged 457 millimeters. About 90 percent of the precipitation falls during October through May. Air temperatures during the year usually 

range from -9T to 29T. Frost may occur in any month. Relative humidity is 

usually low-10 to 20 percent on summer afternoons except during storms. 

SOILS 

Soils supporting conifers cover about 70 percent of the forest and are members 

of the mixed, frigid families of Ultic Haploxeralfs and Ultic Haploxerolls. These 

soils are 3 to 5 feet deep over lava bedrock. Mixed, frigid Ultic Argixerolls 

underlay sagebrush flats. Site Index varies narrowly between 60 and 80 and 

averages 72 (Meyer 1938). 

Figure 1 -A wide range of stand structures and age classes from young 

plantations to old-growth stands are found on Blacks Mountain Experimental Forest. 

USDA Forest Service General Technical Report PSW-119. 1990. 
MAIN COMMUNITIES 

Interior Ponderosa Pine (SAF 237), which occupies 3715 hectares, is the only 

forest cover type on the Experimental Forest (Eyre 1980). Species composition 

varies within the type, however. White fir (Abies concolor var. lowiana [Gord.] 

Lemm.) and incense-cedar (Libocedrus decurrens Torr.), absent in stands within 

the lower portion of the basin, become increasingly abundant at higher elevations. 

The remaining 437 hectares are poorly drained flats occupied by sagebrush and 

grass. 

DATA BASES 

Road and topographic maps are available. In 1933 and 1934 the Experimental 

Forest was completely inventoried on a 1-hectare grid. Timber type maps and inventories were prepared by compartments and revised after various harvests. Computerized stem maps and inventories are available for 20-year periods on 48 

8-hectare parcels. The Lassen National Forest staff has mapped the soils to the 

family 1evel.l This survey supersedes a more detailed survey conducted by 

University of California, Berkeley, students in 1940.2 

EXAMPLES OF RESEARCH 

0 Growth of stagnated stands after thinning 

Long-term effects of partial cutting 

Comparing even-aged and uneven-aged silvicultural systems. 

FACILITIES 

The Blacks Mountain Experimental Forest has no facilities. Temporary office 

space, equipment storage, and gasoline may be available at the Forest Service's 

Bogard Work Center (19 road km southeast) or Hat Creek Work Center and the 

Forest Insect Laboratory of the Pacific Southwest Research Station (48 road km 

northwest). Gasoline and food can be obtained at Old Station (32 road km west). 

Complete services are available in Susanville, 64 road kilometers southeast of 

Blacks Mountain. 

'Available from the Lassen National Forest, Susanvffle, Calif. 

'Data on file at the Pacific Southwest Research Station, Redding, Calif. 

USDA Forest Service Geneml Technical Report PSW-119. 1990. 
BLACKS MOUNTAIN Experimental Forest 

CONTACT ADDRESS 

Project Leader 

Silviculture of California Conifer Types 

Silviculture Laboratory 

2400 Washington Avenue 

Redding, California 96001 

(916) 246-5342 

LOCATION 

Blacks Mountain Experimental Forest (lat. 40Â¡40 N., long. 121'10' W.) lies 

within portions of T. 33 N., R. 7 E. and T. 33 N., R. 8 E., MDM., 64 road kilometers northwest of Susanville, Lassen County (see map). About half of the Forest 

lies in a gently rolling basin; the remainder extends up the mouelate slopes of 

Blacks Mountain to the north and of Patterson and Cone Mountains to the east. 

Elevations range from 1700 to 2100 meters. 

Access to within 8 kilometers of the Experimental Forest is available all-year 

via State Route 44. Access to the boundary and within the Forest is available 

during summer and fall via an intensive system of surfaced and unsurfaced roads. 

None of these roads is maintained in the winter, and many may be impassable 

when wet. 

USDA Forest Service General Technical Report PSW-119. 1990. 

1 Mile 

1 Kilometer 1 


m 

USDA Forest Service General Technical Report PSW-119. 1990. 
CHALLENGE 


Experimental Forest 

The Challenge Experimental Forest comprises 1446 hectares surrounding the town 

of Challenge. The property was deeded to the U.S. Government as a place for 

field studies and for demonstration of forest management practices on stands of 

second-growth ponderosa pine (Pinus ponderosa Dougl. ex Laws. var. ponderosa) 

and associated species (fig. 2). Results of studies conducted here were expected to 

be directly applicable to more than 800,000 hectares of low elevation, highly 

productive sites on the west slope of the northern Sierra Nevada. 

The Experimental Forest, formally designated in 1942, was not activated until 

1958. Early research sought answers to two major questions: (1) How to grow and 

harvest young-growth (80-100 years old) ponderosa pine to ensure adequate regeneration, and (2)how to dispose of logging slash to reduce fire hazard and ensure 

Figure 2-Clearcuttlng with natural regeneration was successfully applied to the secondgrowth stands of ponderosa pine and associated species on the Challenge Experimental 

Forest. 

USDA Forest Service General Technical Report PSW-119. 1990. 
CHALLENGE Experimental Forest 

adequate regeneration. Both even-aged (clearcutting, seedtree, and shelterwood) 

and uneven-aged (group- and single-tree selection) management systems were 

studied. Timber harvesting was accomplished through a cooperative agreement 

with the Soper-Wheeler Company3 of Strawberry Valley, California. Management 

of native California hardwoods, field testing of hybrid and introduced pine species, 

and amount and pattern of soil moisture depletion by individual trees were other 

important early studies. Experiment Station personnel were stationed at Challenge 

from 1958 until 1982 with office and laboratory facilities in the La Porte Ranger 

Station. The number of permanent, full-time personnel reached a maximum of two 

research foresters, two technicians, and a secretary when most of the regeneration 

cutting experiments were installed in the early 1960's. 

Stand conditions are as follows. Uncut or partially cut sawtimber stands 

occupy about 930 hectares in which volumes of the conifer componcr" average 322 

cubic meters per hectare. Regenerated clearcuts as old as 25 years occupy about 

514 hectares. Many of the clearcuts occupied by woody shrubs and poorly stocked 

with conifers were mechanically cleared of shrubs and interplanted with ponderosa 

pine and Douglas-fir (Pscudorsuga menziesii [Mirb.] Franco var. menziesii) during 

1982-1987. 

CLIMATE 

The climate is Mediterranean in that summers are warm and dry, and winters 

are cool and wet. Mean annual precipitation is 1727 millimeters, 98 percent of 

which falls between October and May. Occasional snowfalls melt rapidly leaving 

the ground free of snow most of the winter. Mean annual temperature is 13Â°C 

Mean maximum temperature of 21Â° is reached in July, and mean minimum 

temperature of 6Â° is reached in January. 

SOILS 

Most soils are old and deep. The Aiken and Sites Series cover most of the 

Experimental Forest. Site index (Powers and Oliver 1978) averages 100. 

-- -- -- .- -

'Mention of trade names or products is for information only and docs not imply endorsement by 

the U.S. Department of Agriculture. 

USDA Forest Service General Technical Report PSW-119. 1990. 
MAIN COMMUNITIES 

Pacific Ponderosa Pine (SAF 245) is the major forest cover type (Eyre 1980). 

Sierra Nevada Mixed Conifer (SAF 243), California Black Oak (SAF 246), and 

Pacific Ponderosa Pine-Douglas-fir (SAF 244) types also are present. 

DATA BASES 

Precipitation and maximum and minimum temperatures have been recorded at 

the Challenge Ranger Station since 1938.4 Soils have been mapped both by the 

Cooperative Soil Vegetation Survey5 and the University of California, Davis, in 

cooperation with Yuba County (Herbert and Begg 1969). The timber was inventoried in 1938 and 1939, and again in 1979. 

EXAMPLES OF RESEARCH 

1Management of native hardwoods 

a Effect of timber harvesting on soil nitrogen transformations and mobility 

1Influence of initial spacing and woody understory vegetation on growth and 

development of planted ponderosa pine 

Â Regeneration following single-tree and group selection cutting 

1Interspecies relationships in California mixed conifers 

a Influence of crown mass on litter decomposition and nutrient release 

1Evaluation of ponderosa and sugar pine progeny derived from phenotypically 

superior trees. 

'Data on file at the Pacific Southwest Research Station, Redding, Calif. 

'Maps and legends for quadrangles 39 D-3 and 50 A-2 are available from California State 

Cooperative Soil-Vegetation Survey, California Department of Forestry and Fire Protection, Sacramento. 

USDA ForestService General Technical Report PSW-119. 1990. 
CHALLENGE Experimental Forest 

FACILITIES 

The Challenge Experimental Forest has no facilities other than a small shed 

for storage of field equipment. Temporary office space and equipment storage 

may be available at the La Porte Ranger Station. Gasoline and general merchandise can be obtained in the town of Challenge, but not lodging. The nearest accommodations are in Oroville or Marysville. 

CONTACT ADDRESS 

Project Leader 

Silviculture of California Conifer Types 

Silviculture Laboratory 

2400 Washington Avenue 

Redding, California 96001 

(916) 246-5342 

LOCATION 

The Challenge Experimental Forest surrounds the small community of Challenge, Yuba County, which is 42 road kilometers southeast of Oroville and 56 road 

kilometers northeast of Marysville (see map). It occupies portions of T. 19 N., R. 

7 E., MDM (lat. 3998' N., long. 121Â°13 W.). Elevations range from 730 to 1130 

meters. 

Access to the Experimental Forest is available all-year via the paved 

Marysville-La Porte Road. Access within the Experimental Forest is available 

most of the year via one paved road and a system of graveled but unplowed roads. 

USDA Forest Service General Technical Report PSW-119. 1990 


NORTH MOUNTAIN 


Experimental Area 

The North Mountain Experimental Area (NMEA) was established on January 8, 

1964, when land previously administered by the Bureau of Land Management, 

U.S. Department of the Interior, was withdrawn from all appropriation under the 

Public Land laws including mininglmineral leasing laws by Public Land Order 

3221. This withdrawal occurred by authority of the President, and pursuant to 

Executive Order 10355 of May 26, 1952. 

The NMEA contains a total of 4348 hectares. Nearly the entire area is 

covered with chaparral that is representative of southern California, low elevation, 

interior nontimbered wildlands. No unique or special features are found within the 

MA. The Bureau of Land Management land examiner described the area as 

"badlands," created apparently by uplifting along the Hot Springs Fault line. Three 

major drainages dissect the NMEA: Potrero, Poppet, and Indian Creeks. All three 

are ephemeral. Since 1983, nearly all of the vegetation on the Experimental Area 

has burned. A major fire in 1932 

burned over 80 percent of the area, 

and again in 1967 the Bailiff Fire 

burned about 60 percent of the 

NMEA. Use of the Area is subject 

to valid existing rights and is limited 

to activities directly related to 

research in problems of prevention 

and control of forest and range fires. 

Early studies at the North 

Mountain Experimental Area centered on fuelbreaks and fuel 

properties (fig. 3). Plant control 

Figure 3-This fuelbreak along the Castile Truck Trail was a part of the extensive 

fuelbreak research conducted by the Forest Fire Laboratory In Rlverslde. 

USDA Forest Service General Technical Report PSW-119. 1990. 17 
NORTH MOUNTAIN Experimental Area 

research was conducted in two main categories (fig. 4): (1) the eradication of 

either selective brush plants or all vegetation, and (2) the reduction of plant growth 

with growth-inhibiting substances. The research centered around the use of 

herbicides which were believed to give the most effective and economical control 

of brush regrowth in established fuelbreaks. Another study concerned shrub seed 

production, dispersal, and deposition on chaparral vegetation to develop better 

techniques for reducing the volume of hazardous brush fuels. 

Other studies involved development of a low volume shrub that would slow 

down or repel fires and the use of sheep to reduce fuel volume on fuelbreaks. 

Studies to determine fuel properties affecting fire behavior of charnise (Adenostoma fasciculatum) and other species were included. North Mountain was also the 

site of wind pattern investigations to compare collected wind data with predictions 

from theoretical models of valley convections (fig. 5). 

Figure 4- The use of growth Inhibitors on this previously burned site decreased the vegetative growth of the sprouts. 

USDA Forest Service General Technical Report PSW-119. 1990, 
NORTH MOUNTAIN Experimental Area 

CLIMATE 

The climate of the NMEA is typically Mediterranean. Due to its inland location, summers can be quite hot and dry,and winters cool and wet. Mean maximum temperatures over 3OT and relative humidity values below 35 percent are 

typical for California inland stations. 

Mean temperatures for Hemet (8 krn southwest) are as follows: 

January July 

Minimum 3-C 15Ãˆ 

Maximum 16Ãˆ 32Ãˆ 

The annual precipitation is only about 250 millimeters. Rain falls primarily 

between October and April. January is typically the wettest month, with some 50 

millimeters of precipitation. 

Figure 5-Surface weather data were used for meteor@ 

logical research related to predicting wind velocities. 

USDA Forest Service General Technical Report PSW-119. 1990. 
NORTH MOUNTAIN Experimental Area 

SOILS 

Soils throughout most of the Experimental Area are derived from granitic 

rocks. They vary considerably in depth, are low in organic matter, are moderately 

coarse to very coarse, and neutral to slightly acid with the pH ranging from 6.5 to 

5.8. They are low in fertility and have relatively low water holding capacity. 

Some soils on rolling-to-steep uplands are moderately coarse Lithosols developed 

from mica schists. The surface texture of these soils is predominately sandy loam, 

but grades into clay loam a few inches below the surface. These soils are also low 

in fertility, and are moderately permeable with medium to rapid runoff. Structural 

development is lacking throughout the profile. 

MAIN COMMUNITIES 

The plant community is primarily of the Shrub Formation (Payen and others 

1980). The major subformations are the Chaparral Subformation (Chamise, 

Manzanita, Ceanothus, Mountain Mahogany, and Scrub Oak Series) and the Soft 

Chaparral Subformation (California Buckwheat Series). Several other series are 

present in minor and varying amounts. 

DATA BASES 

Aerial photographs are available: 1:20,000 vertical aerial photographs (1961), 

and oblique aerial photographs (1964). A variety of maps are available: 7.5- and 

15-minute topographic maps, 7.5-minute orthophotographic maps, and field-drawn 

vegetation maps at the series level. Wildfire history maps go back to about the 

1930'~~ 

'Available from the San Bemardino National Forest, San Bemardino, Calif.; and the California 

Department of Forestry and Fire Protection, Sacramento. 

USDA Forest Service General Technical Report PSW-119. 1990 
NORTH MOUNTAIN Experimental Area 

EXAMPLES OF RESEARCH 

1Fuel physical and chemical properties, and arrangement 

1Short- and long-term recovery from prescribed fires under varying conditions 

(fig. 6) 

1Factors that affect hydrologic processes, vegetation dynamics, air pollution, 

and nutrient cycling 

0 Ecological and physiological studies of chaparral. 

There is also a need to establish a long-term meteorological study site or sites 

in southern California brush fields, to avoid site-use conflicts from possible 

vegetation manipulations and to help better understand the meteorological components of management. North Mountain has such areas and is particularly attractive 

from this standpoint. 

Figure 6-Associated with fuelbreak research, prescribed fire was studied as an alternative treatment 

to mechanical and chemical methods. 

USDA Forest Service General Technical Re~ortPSW-119. 1990. 

Mt .Disney 

&el. 2424-r 

Mt.L 


USDA Forest Service General Technical Report PSW-119. 1990. 
ONION CREEK 


Experimental Forest 


The Onion Creek Experimental Forest (OCEF) was established in 1958 to develop 

techniques for increasing water yields from forested lands in the Sierra Nevada 

snow zone. OCEF encompasses about 1200 hectares in five main subbasins. The 

aspect is variable but generally southwest. 

Harvest disturbance is minimal. Approximately 20 percent of the northwestern 

portion of OCEF was harvested in the early 1900's. 

Mapped geologic units include Miocene pyroclastics with Andesitic mudflow 

breccias, volcanic conglomerate, and some tuff. Quaternary glacial deposits 

include Pleistocene moraines, glacial drift and fluvioglacial sand and gravel. No 

mineralization of economic significance is known to exist and no mining claims 

are recorded. A portion of OCEF is formally withdrawn from mineral entry. 

An ecological survey of a portion of the Experimental Forest listed major 

forest plant species including red fir (Abies magnifica A. Murr.), white fir (A. 

concolor var. lowiana [Gord.] Lemm.), sugar pine (Pinus lambertiana Dougl.), 

Jeffrey pine (P. Jeffrey! Grev. & Balf.), western white pine (P. monticola Dougl.), 

lodgepole pine (P. contorta Dougl. ex Laud.), incense-cedar (Libocedrus decurrens 

Tore.), mountain hemlock (Tsuga rnertensiana [Bong.] Cam), and western juniper 

(Juniperus occidentalis Hook.) (Talley 1977). 

Grazing continues on OCEF. Approximately 200 animals pass through it over 

a 3- to 4-day period twice each year. 

Atmospheric deposition has not been measured on the Forest. However, 

annual hydrogen ion loading at the nearby Central Sierra Snow Laboratory of the 

Pacific Southwest Research Station has ranged from 7 to 10 milligrams per square 

meter since 1983. Mean sulfate ion loading since 1983 is 4.5 grams per square 

meter per year at the Snow Laboratory. 

USDA ForestService General Technical Report PSW-119. 1990. 
ONION CREEK Experimental Forest 

CLIMATE 

The climate is typically Mediterranean, with moist, relatively mild winters and 

dry, warm summers. Annual precipitation is about 1060 millimeters at 1830 

meters elevation, with 85-90 percent falling as snow during the winter. Mean 

monthly air temperatures range from -lT in January to 15OC in July. Monthly 

minimum temperatures vary from a low of -14T in January to 1Â° in July while 

monthly maximum temperatures range from about 13T in January to 30Â¡ in July. 

SOILS 

Soils are volcanic Xerumbrepts and have been classified as follows: Ahart/rock 

outcrop (15 pet of the Experimental Forest area), Ahart/Waca (25 pet), Gefo 

variate (5 pet), Meiss (5 pet), Tallac (15 pet), Waca/Meiss (5 pet), Waca~Windy (5 

pet), miscellaneous (20 pet). Cation exchange capacities are 25-35 milliequivalents 

per 100 grams (sum of cations) or 20-30 milliequivalents per 100 grams (ammonium acetate). A Soil Resource Inventory map (third order soil survey) is available. 

MAIN COMMUNITIES 

Red Fir (SAF 207), White Fir (SAP 211), Jeffrey Pine (SAF 247), and (by 

meadow are the main plant communities (Eyre 1980). 

DATA BASES 

Climatic Data 

Air temperature, relative humidity, and precipitation (continuous strip chart) 

data are available since 1976. Coverage before 1976 is sporadic. 

Hydrologic Data 

Continuous stream discharge records are available at five subbasins with areas 

and mean annual discharges as follows: 

Area Discharge 

Imf dlyr 

'2.1 1.3 x 10' 

'1.7 1.3 x 10' 

=l.o 7.7 x 10' 

'1.2 1.1 x 10' 

'0.5 3.8 x 10' 

' October 1958 to September 1964. 

'October 1958 to September 1964, and October 1965 to September 1967. 

USDA Forest Service General Technical Report PSW-119. 1990. 
ONION CREEK Ex~erimental Forest 

A sixth gauging station monitors the entire 9.3-km2 basin. The 20-year mean 

annual discharge (1960 to 1980) for the basin is 8.8 x lo6 cubic meters per year. 

The "main stem" gauge has been in operation since August 1959, except for a 2- 

year period in the early 1980's. The gauge on the smallest subbasin was reactivated in 1983, and has been in operation since then. Snowpack depth and water 

equivalent have been monitored monthly at a snow course since 1937. 

EXAMPLES OF RESEARCH 

Snow hydrology 

Freshwater aquatic biology 

Materials evaluation. 

FACILITIES 

Facilities are minimal: one small cabin with bunk beds for four and an outbuilding; no drinking water. Commercial accommodations are available 11 kilometers away at Soda Springs. The Central Sierra Snow Laboratory is 11 kilometers distant. 

CONTACT ADDRESS 

Project Leader 

Environmental Hydrology of the California Snow Zone 

Pacific Southwest Research Station 

P.O. Box 245 

Berkeley, California 94701 

(4 15) 486-3456 

LOCATION 

The forest is in the north drainage of the American River about 20 kilometers 

west of Tmckee, on the Tahoe National Forest (see map). It is 11 kilometers south 

of Soda Springs, off Old Highway 40. Latitude is 3917' N., longitude is 

120Â¡2lfl5 W. Elevation ranges from 1830 to 2590 meters. 

Main access is along approximately 6.5 kilometers of poorly graded county 

road known as the Soda Springs-Riverton Road. 

USDA Forest Service General Technical Re~ort PSW-119. 1990. 
San Dimas Experimental Forest 


m-m Paved Roads 

' $4 --- - Gravel or Dirt Roads I 

Reservoir 1 

Research Natural Area 

A Mountain or Peak 

USDA Forest Service General Technical Report PSW-119, 1990. 
SAN DIMAS 


Experimental Forest 


The San Dimas Experimental Forest (SDEF) contains some of the earliest and 

longest records from continuously monitored, experimental watersheds in the 

United States. It has been designated by the Man and the Biosphere Program of 

the United Nations as a Biosphere Reserve and by the National Science Foundation 

and the Institute of Ecology as an Experimental Ecological Reserve. Fern Canyon, 

a 550-hectare tributary to San Dimas Canyon, was set aside in 1972 as a Research 

Natural Area (RNA)-a pristine area where only nondestructive research can take 

place. Included in the area is Brown's Flat, a locally unique, mountain meadow 

that supports a grove of ponderosa pine (Pinus ponderosa Dougl. ex Laws.). 

The Experimental Forest was established in response to the need for an 

outdoor laboratory in southern California to study various aspects of watershed 

management. The need for an experimental forest in southern California had been 

recognized since the founding of the California Forest Experiment Station (now 

Pacific Southwest Research Station) in 1926. Edward I. Kotok, Station Director, 

Charles J. Kraebel of the Station's research staff, and Walter C. Lowdermilk of the 

University of California College of Forestry evaluated several potential sites and 

formally recommended the San Dimas site in May 1932. Research operations 

began in January 1933 when J. Donald Sinclair arrived as its first director (then 

called scientist-in-charge), and this has long been regarded as the actual (if unofficial) beginning of the Experimental Forest. The Forest was formally established 

on March 28, 1934. 

The Experimental Forest is located within the Angeles National Forest and 

comprises 6786 ha of steep, rugged terrain in the southeastern San Gabriel Mountains, with elevations ranging from 400 to 1700 m and slopes averaging 68 percent 

(34 degrees). It encompasses the entire upper watersheds of the Big Dalton and 

San Dimas drainage basins. Each of these basins is controlled by a large flood 

control dam, built and maintained by the Los Angeles County Department of 

Public Works. The two dams are located within the Experimental Forest just 

USDA Forest Service General Technical Report PSW-119. 1990. 

SAN DIMAS Experimental Fores

The course of research studies has changed considerably since the establishment of the San Dimas Experimental Forest. The original research was directed 

towards increasing water yield, but new problems have led to new avenues of 

research. Currently, the principal efforts are directed towards studying erosion and 

sediment movement, water quality, postfire ecosystem recovery and the effects of 

smog, as well as the continuation of several earlier programs. Because of its 

accessibility to several nearby universities, research by their staffs and faculties is 

an important part of the work at San Dimas. The forest also serves as an outdoor 

teaching laboratory for local colleges, high schools, and educational groups. 

Most major chaparral species are represented on SDEF. The dominant species 

include charnise (Adenostoma fasciculatum H. & A.), Ceanothus spp., California 

scrub oak (Quercus dumsa Nutt.), sumac (Rhus spp.) and manzanita (Arctostaphy10s spp.). Soft chaparral species include yerba santa (Eriodictyon spp.), California 

buckwheat (Eriogonum fasciculatum Benth.), Lotus spp., and lupine (Lupinus spp.). 

Large grass covered areas in Bell and Monroe Canyons are the result of 

studies aimed at increasing water yield by converting brush to grass. Begun in the 

late 1950's, this conversion produced some unexpected results in the form of 

increased ground failures. The effects of this watershed manipulation are still 

being studied. 

Many tree species, especially coast live oak (Quercus agrifolia Nee.), California sycamore (Platanus racemosa Nutt.), California bay (Umbellularia californica 

[H. & A.] Nutt.), white alder (Ainus rhombifolia Nutt.), and bigleaf maple (Acer 

macrophyllum Pursh) can be found in and near the riparian zones. Several old 

stands of bigcone Douglas-fir (Pseudotsuga macrocarpa [Vasey] Mayr.) are 

gradually disappearing, possibly because of recurring fires and smog damage. At 

higher elevations on north-facing slopes there are woodlands with large stands of 

canyon live oak (Quercus chrysolepis Liebm.) interspersed with bigcone DouglasUSDA Forest Service General Technical Report PSW-119. 1990, 
SAN DIMAS Experimental Forest 

Figure 9-Oak woodland chaparral vegetation in the Fern 

Canyon Research Natural Area is typical of the higher eteva- fir plus a few ponderosa pine and sugar pine (Pinus 

tions on the San Dimas Experimental Forest. Bigcone Douglas-fir lambertiana Dougl.) (fig. 9). (An arboretum (Pseudotsuga macrocarpa) in the right center of the photograph is a typical associate of chaparral types at this eleva- featuring both native and introduced trees is tion-about 1515 meters. (Photo ca. 7935) 

located at Tanbark Flats). 

Wildlife is abundant and varied in the San 

Dimas Experimental Forest. Over 40 species of 

mammals and over 180 species of birds either live 

in the experimental forest or visit it annually. In 

addition there are over 35 species of reptiles and 

amphibians, and numerous migratory waterfowl 

and birds associated with urban environments. 

A publication describing the research history 

of the Experimental Forest includes complete 

species lists for both plants and animals (Dunn and others 1988). 

CLIMATE 

The climate is typically Mediterranean with hot, dry summers and cool, wet 

winters. Annual precipitation at Tanbark Flats is 705 millimeters and falls primarily as rain. Snow is common only in the northeastern part of the Forest where elevations exceed 1500 meters. The rainy season runs from November through 

March. The coolest month of the year is January and the warmest is August. 

Mean monthly temperatures at Tanbark Flats are shown below: 

Month Mean temperature 

OC 

January 8.5 

February 9.1 

March 9.6 

April 12.1 

May 14.0 

June 17.6 

July 22.3 

August 22.6 

September 21.1 

October 16.6 

November 12.3 

December 10.0 

USDA Forest Service General Technical Report PSW-119. 1990 
SAN DIMAS Experimental Fores

SOILS 

The soils of the Experimental Forest are generally shallow, rocky and poorly 

developed. Most are derived from one of two parent materials-a Precambrian 

complex of gneisses and schists, and a Mesozoic igneous complex (primarily 

tonalite, and granodiorite). The most extensive soil groups are coarse-loamy, 

mixed, thermic, shallow Typic Xerorthents and fine-loamy, mixed, thermic Mollic 

Haploxeralfs, the latter developing primarily on the granitic parent materials and 

the former on both types of parent material. At higher elevations (above 1370 m) 

these same parent materials underlie fine-loamy, mixed, mesic Mollic Haploxeralfs. 

Around Johnstone Peak in the southwestern part of the Forest is a small area of 

fine, mixed, thermic Typic Argixerolls developed over a Miocene volcanic parent 

material (andesite and rhyolite). On gentler slopes small areas of coarse-loamy, 

mixed, thermic Pachic Haploxerolls can be found. These are underlain by parent 

materials of schist and andesite. 

MAIN COMMUNITIES 

According to Kuchler's (1977) classification there are three communities on 

the Experimental Forest: chaparral (Kuchler 29), coastal sagebrush (Kuchler 32). 

and California mixed hardwood forest (Kuchler 23). Locally, chaparral is called 

"hard chaparral" and coastal sagebrush is called "soft chaparral." The California 

mixed evergreen type includes two communities that are locally recognized as 

distinct types-oak woodland (Quercus spp./Pseudotsuga macrocarpa) and riparian 

woodland (QuercuslAlnuslAcerlPlatanus). 

DATA BASES 

Reports and Publications 

A master file of over 500 reports and publications has resulted from work 

done on the Experimental Forest. In addition to published papers, this file includes 

unpublished reports, surveys, study plans and miscellaneous data, as well as 

complete plant and animal species lists. 

USDA Forest Service General Technical Report PSW-119. 1990, 
SAN DIMAS Experimental Forest 

Long-Term Records (more than 20 years) 

Available long-term records cover precipitation, temperature, relative humidity, 

wind direction and speed, evaporation, streamflow and sediment yield. The rainfall 

records include the 62-year record from Tanbark Flats and the 110-year record 

from Glendora. For the local area (Los Angeles County), the Glendora record is 

second in length only to the 113-year record from downtown Los Angeles. 

Short-Term Records (less than 20 years) 

Short-term records cover solar radiation, hillslope runoff and erosion, acid 

rainfall, dry and wet deposition of air pollutants, and chemical pollutants in 

streamflow (especially nitrates). 

Mops and Aerial Photos 

Available maps include soils, vegetation, geology and topographic features 

(such as slope facets, steepness, aspect). Aerial photo sets date back to the late 

1930's. Most sets cover only part of the Experimental Forest. 

EXAMPLES OF RESEARCH 

0 Fire effects and postfire recovery of watersheds 

Effects of fire on ecosystems 

Effects of fire on the physical environment 

Postfire recovery of ecosystems 

Postfire erosion and recovery 

Postfire water yields 

1 Erosion and sedimentation 

Hillslope processes 

Sediment storage and movement in channels 

Debris flow dynamics 

Sediment budgets 

Chaparral and woodland ecology 

Air quality 

Acid rainlfog 

Atmospheric deposition 

Nutrient cycling 

USDA Forest Service General Technical Report PSW-119. 1990. 
SAN DIMAS Experimental Forest 

Â Wildland hydrology 

Water quality 

Water yield 

Soil water and groundwater movement 

Prescribed fire applications 

Â Geologic hazards 

Â Wildlife studies 

Â Climatic studies. 

FACILITIES 

The field headquarters at Tanbark Rats has office space, living quarters and 

laboratory facilities, all with running water, electricity, and telephone communications. The availability of these facilities is limited and must be scheduled in 

advance. Tanbark Flats also has an all-purpose shop, limited facilities for equipment storage, a fireproof vault for records storage, a dining and assembly hall, and 

a heliport. 

Field research facilities include over 50 gauged watersheds, the lysimeter 

complex, the Fern Canyon Research Natural Area, two major dams and reservoirs 

and three plantations of domestic and introduced trees. The gauged watersheds 

range in area from 1 to 4200 hectares, and many have debris basins for trapping 

sediment. 

Other features of the Forest include internal access via 10 roads and an 

extensive network of trails and availability of labor crews on request (this may be 

limited by other demands, especially during fire season). The entire Experimental 

Forest is closed to the public and entry requires the issue of a use permit and 

necessary keys. This helps insure that ongoing studies are subjected to a minimum 

of disturbance. 

USDA Forsst Service General Technical Report PSW-119. 1990. 
SAN DIMAS Experimental Forest 

CONTACT ADDRESSES 

Project Leader 

Ecology and Fire Effects in Mediterranean Ecosystems 

Forest Fire Laboratory 

4955 Canyon Crest Drive 

Riverside, CA 92507 

(714) 351-6560 

and 

Forest Manager 

San Dimas Experimental Forest 

110 N. Wabash Avenue 

Glendora, CA 91740 

(818) 963-5936 

LOCATION 

The San Dimas Experimental Forest (lat. 34'12' N., long. 117O46' W.) is 

bordered on the south by the cities of Glendora, San Dimas, and La Verne (see 

map). Elevation ranges from 400 to 1700 meters. 

Primary access is from Glendora via Glendora Mountain Road and Big Dalton 

Canyon Road. The field headquarters at Tanbark Flats is 16 kilometers from 

Glendora via Big Dalton Road and 24 kilometers via Glendora Mountain Road. 

Access is also available from the town of San Dimas. 

The forest manager's office is located in Glendora at the Mount Baldy District 

Ranger Station. Limited office space is available at the manager's office. Also 

available in Glendora are clerical support to aid in searching records and access to 

the Forest Service-wide computer network. The Forest Fire Laboratory of the 

Pacific Southwest Research Station is 64 kilometers east of the Glendora office via 

freeway, in Riverside. 

USDA Forest Service General Technical Report PSW-119. 1990. 

USDA Forest Service General Technical Report PSW-119. 1990. 
SAN JOAQUIN 


Experimental Range 

The San Joaquin Experimental Range (SJER) has been in existence since 1934. 

It was purchased by the Forest Service and is managed by California State University, Fresno, for research and educational purposes under a long-term agreement 

with the Pacific Southwest Research Station. SJER was the Annual Grassland 

Biome site for the International Biological Program during the 1970's and is 

currently a Man and the Biosphere Reserve. 

SJER consists of about 1820 hectares (including a 33-ha livestock exclosure 

built in 1934), cross-fenced into 34 range units varying in size from 7 to 295 

hectares (fig. 10). 

Figure 10-Numbered range units on the San Joaquin Experimental Range. Area of range units is listed at left. Hectares 

protected from livestock are in parentheses. 

USDA Forest Service General Technical Report PSW-119. 1990. 
SAN JOAQUIN Experimental Range 

Vegetation on SJER includes annual grasslands and blue oak-digger pine 

woodlands (fie. 11). Annual grasslands consist largely of introduced grass species, 

such as wild oat (Avena fatua), soft chess (Bromus mollis), ripgut brome (Bromus 

diandrus), red brome (Bromus rubens), wild barley (Hordeum spp.), and foxtail 

fescue (Vulpia megalura). Common forbs include broadleaf filaree (Erodium 

botrys), redstem filaree (Erodium circutarium), true clovers (Trifolium spp.), 

popcorn flower (Plagiobothrys nothofulvus), turkey mullein (Eremocarpus 

setigerus), and many others. In the blue oak woodland, the most common trees are 

blue oak (Quercus douglasii), interior live oak (Quercus wislizenii), digger pine 

(Pinus sabiniana), and California buckeye (Aesculus californica). Wedgeleaf 

ceanothus (Ceanothus cuneatus) shrubs are also common. 

Cattle on SJER consist of a breeding cow herd (about 275 cows with or 

without calves), owned by California State University, Fresno. Except for grazing 

systems experiments, grazing is continuous year-long (fig. 12). 

Figure 1 1 -Much of the San Joaquin Experimental Range consists of blue oak savanna. 

40 USDA Forest Service General Technical Report PSW-119. 1990 
SAN JOAQUIN Experimental Range 

CLIMATE 

The climate is typically Mediterranean, with moist, mild winters and dry, hot 

summers. Annual precipitation ranges from 254 to 813 millimeters, with a mean 

of 483 millimeters and most falling as rain between October and April. Monthly 

mean air temperatures range from about 6Â¡ in January to about 27Â¡ in July. 

Monthly minimum temperatures vary from a low of slightly above freezing in 

January to over 16T in July. Monthly maximum temperatures range from about 

10Â¡ in January to almost 38T in July. 

SOILS 

Soils are of granitic origin and most are less than 76 centimeters deep. On 

upland sites, Ahwahnee Series (Mollic Haplustalfs) soils are common, covering 

about 96 percent of SJER. These typically have A horizons that are grayish brown 

to brown, slightly acidic, and low in organic matter content. Visalia Series soils 

(Cumulic Haploxerolls) are found on alluvial or swale sites, are generally darker, 

deeper, and more productive than Ahwahnee Series soils. 

Figure 12-Grazing by domestic cattle is a major land use at the San 

Joaquin Experimental Range. 

USDA Forest Service General Technical Report PSW-119. 1990. 4 1 
SAN JOAQUIN Experimental Range 

MAIN COMMUNITIES 

Blue Oak-Digger Pine (Eyre 1980), California Prairie, and Blue Oak-Digger 

Pine Forest (Kuchler 1977) are the main communities on the Experimental Range. 

DATA BASES 

Climatic Data 

Daily precipitation and daily temperatures (minimum and maximum) are 

available since 1934. 

Plant Data 

Peak forage production is available since 1934. For some years, detailed 

seasonal production and composition data are also available. A wide variety of 

producer and consumer data were collected for 3 years (1973-1975) when SJER 

was the Annual Grassland Biome Site for the U.S. International Biological Program. 

Livestock Data 

Figures on stocking rates and weight gains are available for various years. 

Wildlife Data 

Biological data for various years are available for western rattlesnakes (Crotalus viridis), red-tailed hawks (Buteo jamaicensis), California quail (Callipepla 

californica), California ground squirrels (Spermophilus beecheyi), avian community 

structure, and other wildlife aspects. 

EXAMPLES OF RESEARCH 

Â Oak ecology 

8 Wildlife habitat-relationships 

Bird population trends 

8 Livestock science. 

USDA Forest Service General Technical Report PSW-119, 1990. 
SAN JOAQUIN Experimental Range 

FACILITIES 

A variety of facilities is available (fie. 13). Dormitory facilities are limited. 

Most summertime visitors prefer to obtain food and air-conditioned lodging in 

Fresno or Madera, both about 40 kilometers away. Shop and limited laboratory 

facilities are available for routine plant drying, sorting, and weighing. Some restrictions on facilities are imposed by previously scheduled use. 

CONTACT ADDRESS 

Manager 

San Joaquin Experimental Range 

24075 Highway 41 

Coarsegold, CA 93614 

(209) 868-3349 

LOCATION 

The San Joaquin Experimental Range is located about 40 kilometers north of 

Fresno, on Highway 41, in Madera County (see map). Latitude is 3795' N., and 

longitude is 119045' W. Elevation ranges from 210 to 520 meters. 

Figure 13-The office building also contains laboratory and conference facilities. 

USDA Forest Service General Technical Report PSW-119. 1990. 


STANISLAUS-TUOLUMNE Experimental Forest 

Obtaining adequate reproduction of sugar pine (Pinus lambertiana Dougl.) by 

natural seeding and planting was stressed by seedtree cuttings and small clearcuttings. Several plantations, areas of natural young-growth, and large blocks of 

diverse species and age classes that virtually are uncut, provide great potential for 

silvicultural and ecological research in this important and complex forest type (fig. 

15). This research potential was recognized by the United Nations Educational, 

Scientific and Cultural Organization's Program on Man and the Biosphere, which 

formally recognized the Forest as part of an international network of Biosphere Reserves in 1977. 

CLIMATE 

The climate is characterized by warm, dry summers and 

cold, wet winters. Annual precipitation averages 940 millimeters, more than half falling as snow between December 1 and 

March 31. Snow, in exceptional winters, may accumulate to 

depths over 3 meters. Some drifts persist until about May 20. 

Little precipitation falls during June through September. Air 

temperatures during the year usually range from -23Â° to 35OC. 

Average monthly minimum and maximum air temperatures range 

from -7% and PC for January to 6Â° and 27OC for July. The 

growing season is about 112 days. 

SOILS 

Moderately deep, sandy to fie sandy loam soils of the 

Holland Series are widespread in the Experimental Forest. The 

soils are residual, derived from granite or diorite. On the higher 

slopes and ridges, soils from the lava caps are shallow and 

support poor tree growth. Overall, however, site quality is high. 

Site Index is estimated to be about 110 (Meyer 1938). 

Figure IS-Large blocks of diverse species and 

age classes on the Stanislaus-Tuolumne Experlmental Forest provide great potential for 

silvicultural and ecological research. 

USDA Forest Service GeneralTechnical Report PSW-119. 1990. 




SWAIN MOUNTAIN Experimental Forest 

The third and current period of heavy cutting is to extend the shelterwood 

research results to operationally large areas and create extensive acreage of fir regeneration for future research. To these ends about one third of the Forest is 

currently being regenerated through shelterwood cutting. 

CLIMATE 

The climate at Swain Mountain can be classified as cool and moist even 

though there is a 4- to 5-month summer dry spell. Precipitation averages from 

1243 to 1270 millimeters per year, almost all of which falls between October and 

March. Eighty percent of the moisture falls as snow, and snowpacks of 3 to 4 

meters are common in February. In exceptionally wet years with late spring 

snows, drifts can persist until late July. Between April (or May) and October, 

precipitation is negligible and from scattered thunder showers. Winter temperatures generally do not fall below -23T and summer temperatures only occasionally 

exceed 29" C. Average monthly minimum and maximum air temperatures range 

between -17OC and 4T for January and between 4Â° and 27T for July. 

SOILS 

Soils vary from 0.6 to 2.4 meters deep and are generally well drained except 

in association with small "shoestring" meadows. The soils are derived in place 

from weathering of the andesite and associated ash. The lava flows that formed 

the mountain are occasionally visible at the surface. Soil series have not been 

mapped. Site quality varies but in general is good-a Dunning Site I1 or Site 

Index 150 at 300 years. 

MAIN COMMUNITIES 

The forest cover types on the Experimental Forest include large areas of Red 

Fir (SAF 207), White Fir (SAF 21 I), and small areas of Lodgepole Pine (SAF 218) 

cover types (Eyre 1980). White fir predominates at the low to mid elevations 

(1737 to 1890 m) with the proportion of red fir increasing with increasing elevaUSDA Forest Service General Technical Report PSW-119. 1990. 

1 SWAIN MOUNTAIN Experimental Forest 

Low altitude color aerial photos, approximate scale 1:3800 are available. 

Flights were made in 1980 and 1981 and show all experimental cuttings to that 

date. 

EXAMPLES OF RESEARCH 

Natural regeneration 

0 Growth and yield 

Â Pathology 

Site preparation 

0 Effects of insects on cone crops 

Mortality prediction for old-growth fir. 

FACILITIES 

There are no facilities on the Foresi, and no surface water is available. Unimproved campgrounds are along Robbers Creek, which forms part of the boundary 

of the Forest. Water from the creek is not potable. 

CONTACT ADDRESS 

Project Leader 

Regeneration of California Forests 

Silviculture Laboratory 

2400 Washington Avenue 

Redding, California 96001 

(9 16) 246-5461 

USDA Forest Service General Technical Report PSW-119. 1990, 
LOCATION 

Swain Mountain lies at latitude 4095' N. and longitude 12196' W., 13 kilometers north of Westwood (see map). The Experimental Forest covers the entire 

mountain and rises from 1737 to 2149 meters above mean sea level. 

The Forest can be reached via County Road A-21, a paved road that is kept 

clear of snow all winter. Neither the approximately 1.6 kilometers of all-weather 

road between the highway and the Forest, nor the extensive road network on the 

Forest are kept open during winter. Access between approximately mid-December 

and early May is limited to snowmobile, skis, or similar transportation. All of the 

current 41.8 kilometers of all-weather road is accessible by automobile, except 

when limited by snow. All parts of the Forest are easily reachable by short walks 

over gentle terrain. 

USDA Forest Service General Technical Report PSW-119. 1990. 
'TO 

SaUciill 

Flat 

camparound 

BlacK ROCK Road 

USDA Forest Service General Technical Rewrt PSW-119. 1990. 
TEAKETTLE CREEK 


txperimental horest 


Three 200-hectare watersheds were first selected for study in 1934. Streamgauging 

stations were constructed on five subdrainages in the mid 1930's, and data on snow 

accumulation and melt, and precipitation and streamflow were collected. In 1942 

the work was halted due to World War 11. Studies were resumed in 1957 and the 

approximately 1300-hectare Experimental Forest was formally dedicated in 1958. 

The original objective was to determine methods of managing watersheds in representative fir and fir-pine types for the maximum beneficial yield of water consistent with control of floods and erosion. 

An ecological survey of a portion of the Experimental Forest was written in 

1975. Major forest species listed in that study include red fir (Abies magnifica A. 

Mum.), white fir (A. concolor var. lowiana [Gord.] Lemm.), sugar pine (Pinus 

lambertiana Dougl.), Jeffrey pine (P. jeffreyi Grev. & Balf.), western white pine 

(P. monticola Dougl.), incense-cedar (Libocedrus decurrens Ton-.), mountain 

hemlock (Tsuga mertensiana [Bong.] Cam.), and western juniper (Juniperus 

occidentalis Hook.). Lodgepole pine (P. contorta Dougl. ex Laud.) grows on the 

higher portions of the Experimental Forest. Subordinate species include Arctostaphylos nevadensis A. Gray, Arctostaphylos patula Greene, Ceanothus cordulatus 

Kellogg, Chrysolepis sempervirens [Kellogg] W. Dud., Prunus emarginata [Dougl. 

ex Hook.] Walp., and Quercus kelloggii Newb. (Griffin 1975). 

Atmospheric deposition has not been measured onsite. Hydrogen ion loading 

has been monitored since 1980 at Giant Forest in Sequoia National Park, 55 

kilometers south southwest. At Giant Forest hydrogen loading in 1982 was 10 

milligrams per square meter with a 4-year mean (1980-1984) of 4.5 milligrams per 

square meter per year. The 1982 sulfate ion loading at Giant Forest was 3.9 grams 

per square meter with the 4-year mean (1980-1984) 3.5 grams per square meter per 

year. 

\ Forest Service General Technical Report PSW-119, 1990, 
TEAKETTLE CREEK Experimental Forest 

Harvest disturbance is minimal. A minor "sanitation" cut in 1979 along roads 

to the gauging stations is the only known timber removal. 

Mapped geologic units are primarily Triassic metarnorphics, mainly quartzite, 

with some Miocene olivine basalt on top of the quartzite. Only the lower elevation 

southeastern comer of the Forest is granodiorite. The entire Experimental Forest is 

withdrawn from mineral entry. 

CLIMATE 

The climate is typically Mediterranean, with moist, relatively mild winters and 

dry, warm summers. Annual precipitation is about 1120 millimeters at 2100 

meters elevation, with most falling as snow between November and May. Mean, 

maximum, and minimum July air temperatures are 17T, 30Â¡C and 3T. Winter 

records are unavailable. 

SOILS 

Soils are generally Xerumbrepts and Xeropsamments typical of the southwestem slope of the Sierra Nevada. Mapped series, with percentage of Forest area in 

parentheses, include Cagwin (15 pet), Cannell (15 pet), Sirretta (10 pet), Ledford 

(15 pet), Toem (10 pet), Umpa (5 pet), Waca (5 pet), Windy (5 pet), Shaver/ 

Ledford (5 pet), and miscellaneous (15 pet). The cation exchange capacity, determined by the sum of cations method, is 25-30 milliequivalents per 100 grams. 

MAIN COMMUNITIES 

Red Fir (SAF 207), Ponderosa Pine-Sugar Pine-Fir (SAF 243), and wet and 

dry meadows are the main communities (Eyre 1980). 

DATA BASES 

Climatic Data 

Data available for 1977 to the present are air temperature, relative humidity, 

USDA Forest Service General Technical Report PSW-119. 1990 

TEAKETTLE CREEK Experimental Forest 

FACILITIES 

The two primary buildings on the Forest are a warehouselgarage and main 

cabin. The cabin sleeps five, and the warehouse has limited maintenance equipment. Laboratory space is not available. A field office of the Pacific Southwest 

Research Station, with office and laboratory facilities, is located in Fresno, about 1 

112 hours driving time away. Lodging is available at Dinkey Creek, approximately 

40 minutes driving time distant. 

CONTACT ADDRESS 

Project Leader 

Wildlife Research and Range Monitoring 

Forestry Sciences Laboratory 

2081 E. Sierra Avenue 

Frcsno, California 93710 

(209) 487-5588 

LOCATION 

Teakettle Creek Experimental Forest is located in the north drainage of Kings 

River about 80 kilomctcrs east of Frcsno, California, on the Sierra National Forest 

and is 12 kilometers southwest of Wishon Reservoir (see map). Latitude is 37%' 

N., and longitude is 119Â°2'25 W. Elevation ranges from 1980 to 2590 meters. 

Main access is along approximately 8 kilometers of graded road from the 

junction with a paved road at Tulc Meadow. 

USDA Forest Service General Technical Report PSW-119. 1990. 

Yurok Redwood Experimental Forest 


' / --- ivel or Dir 

s 

Research Natural Area 

USDA Forest ServiceGeneral Technical Report PSW-119. 1990. 

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 meters 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 ridge tops (about 6.5 ha) and Atwell Series at the lower 

elevations on the southern part of the Forest (about 2.0 ha). Unclassified alluvial 

soils are found along High Prairie Creek on a total of about 32.4 hectares. 

MAIN COMMUNITIES 

The Yurok Research Natural Area supports very dense stands of old-growth 

redwood averaging about 200 square meters per hectare. The two dominant 

vegetation types on the forest are Sequoia sempervirens-Polystichum munitum and 

Ainus rubra-Rubus spectabilis. 

DATA BASES 

Maps 

Soil-vegetation maps are available for the general area. 

Timber Data 

Regeneration after cutting, young stand growth and yield, response to thinning, 

and redwood sprout development were recorded intermittently between 1956 and 

1982. Post-harvest regeneration and effects of shelterwood removal were recorded 

between 1970 and 1985. 

Wildlife Habitat Data 

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 

Stream reaches and distribution of fish species in High Prairie Creek were 

mapped from 1984 to 1987. 

USDA Forest Service General Technical Report PSW-119, 1990, 
YUROK REDWOOD Experimental Forest 

EXAMPLES OF RESEARCH 

0 Salmonid preference for obstacle-formed pools 

0 Stream structure and fish production 

0 Ecology of old-growth forest wildlife habitat community. 

FACILITIES 

Dormitory and office space, garage, storage areas, and several small houses are 

available on an administrative site. However, only some of these facilities are 

maintained on a regular basis. Commercial facilities are available in Crescent City 

and Klarnath. 

CONTACT ADDRESS 

Project Leader 

Timber Management~Wildlife and Fish Habitat 

Interactions in Northern California Forest Types 

Redwood Sciences Laboratory 

1700 Bayview Drive 

Arcata, California 95521-6098 

(707) 822-369 1 

LOCATION 

The Yurok Redwood Experimental Forest is located on the coastal front of the 

North Coast Ranges in northern California, about 2.4 kilometers inland from the 

Pacific Ocean and near the mouth of the Klarnath River, approximately at latitude 

41'35' N. and longitude 12495' W. (see map). Elevation ranges from 457 to 3658 

meters 

The Experimental Forest is readily accessible from U.S. Highway 101, 27.2 

kilometers south of Crescent City and 6.4 kilometers from Klarnath. 

USDA Forest Service General Technical Report PSW-119. 1990. 65 
REFERENCES 


Dunn, Paul H.; Barro, Susan C.; Wells, Wade G., E, Pot!!, Mark A.; Wohlgemuth, Peter M.; Colver, 

Charles G. 1988. The San Dimas Experimental Forest: 50 years of research. Gen. Tech. 

Rep. PSW-104. Berkeley, CA: Pacific Southwest Forest and Range Experiment Station, Forest 

Service, U.S. Department of Agriculture. 49 p. 

Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: 

Society of American Foresters; 148 p. 

Griffin, James R. 1975. Ecological survey of Teakettle Creek candidate Research Natural Area. 

Teakettle Creek Experimental Forest, Sierra National Forest. Unpublished manuscript on file, 

Pacific Southwest Forest and Range Experiment Station, Berkeley, CA, 50 p. 

Hallin, William E. 1954. Unit area control-its development and application. Misc. Paper 16. 

Berkeley, CA: Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture; 10 p. 

Herbert, Fred W., Jr.; Begg, Eugene L. 1969. Soils of the Yuba area, California. Davis: Department of Soils and Plant Nutrition, University of California; 170 p., 41 maps. 

Kuchler, A. W. 1977. The map of the natural vegetation of California. In: Barbour, M. G.; 

Major, J., eds. Terrestrial vegetation of California. New York: Wiley; 909-915. 

Mcyer, Walter H. 1938. Yield of even-aged stands of ponderosa pine. Tech. Bull. 630. Washington, 

DC: US.Department of Agriculture; 59 p. 

Paysen, Timothy E.; Derby, Jeanine A.; Black, Hugh, Jr.; Bleich, Vernon C.; Mincks, John W. 1980. 

A vegetation classification system applied to southern California, Gen. Tech. Rep. PSW-45. 

Berkeley, CA: Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture; 33 p. 

Powers, Robert F.; Oliver, William W. 1978. Site classification of ponderosa pine stands under 

stocking control in California. Res. Paper PSW-128. Berkeley, CA: Pacific Southwest Forest 

and Range Experiment Station, Forest Service, U.S. Department of Agriculture; 9 p. 

Salman, K. A,; Bongberg, J. W. 1942. Logging high risk trees to control insects in the pine stands 

of northeastern California. Journal of Forestry 40(7): 533-539. 

Talley, Steven N. 1977. An ecological survey of the Onion Creek candidate Research Natural 

Area on the Tahoe National Forest, California. Unpubhshed manuscript on file, Pacific 

Southwest Forest and Range Experiment Station, Berkeley, CA; 65 p. 

Taylor, D. W. 1982. Ecological survey of the vegetation of the Yurok Research Natural Area, 

California. Report to: Pacific Southwest Forest and Range Experiment Station, Forest Service, 

U.S. Department of Agriculture, Berkeley, CA. Contract 40-9AD62-793. 

U.S. Department of Agriculture, Forest Service, 1985. Forest Service Manual 4062, Experimental 

Forests and Ranges. 

US. Department of Agriculture, Forest Service. 1987. Region 5 Suppi. 5 and PSW Suppl. 14 to 

Forest Service Manual 4062. 

USDA Forest Service General Technical Report PSW-119. 1990 
APPENDIX-METRIC 


CONVERSION TABLE 

Metric Unit British Equivalent 

kilometer (km) 0.622 mi 

millimeter (mm) 0.039 inch 

centimeter (cm) 0.394 inch 

meter (m) 3.281 ft 

grams per square meter 4.885 x lP3 lb/ft2/y per year 

(dm2/yr) 

hectare (ha) 2.471 acres 

square kilometer (km2) 0.386 square miles 

cubic meters per year (m3/yr) 1.129 x 1P6 ft3/s 

8.107 x lo-'' acre-ftlyr 

liters per second (11s) 0.0369 ft3/s 

degree Celsius PC) (OF- 32) x 0.556 

kilogram (kg) 0.454 lb 

cubic meters per hectare (m3/ha) 7 1.457 bd ftfacre 

USDA Forest Service General Technical Report PSW-119, 1990. 
The Forest Service, U. S. Department of Agriculture, is responsible for Federal leadership in forestry. 

It carries out this role through four main activities: 

0 Protection and management of resources on 191 million acres of National Forest System lands 

0 Cooperation with State and local governments, forest industries, and private landowners to help 

protect and manage non-Federal forest and associated range and watershed lands 

Participation with other agencies in human resource and community assistance programs to 

improve living conditions in rural areas 

0 Research on all aspects of forestry, rangeland management, and forest resources utilization. 

The Pacific Southwest Research Station 

0 Represents the research branch of the Forest Service in California, Hawaii, American Samoa 

and the western Pacific. 

Persons of any race, color, national origin, sex, age, religion, or with any handicapping 

conditions are welcome to use and enjoy all facilities, programs, and services of the 

US. Department of Agriculture. Discrimination in any form is strictly against agency 

policy, and should be reported to the Secretary of Agriculture, Washington, DC 20250.