Federal Research Natural Areas in Oregon and Washington A
Guidebook for Scientists and Educators. 1972.
Pacific Northwest Forest and Range Experiment Station,
Portland, Oregon.
ENVIRONMENT
Ponderosa pine and Douglas-fir forest
characteristic of lower elevations on
the east slope of the Oregon Cascade
Range.
The Persia M. Robinson Research Natural
Area was established in March 1948. It exemplifies the ponderosa pine (Pinus ponderosa)
and
mixed
pine-Douglas-fir
(Pseudotsuga
menziesii) typifying the lower forest zone on the
east slope of the northern Oregon's Cascade
Mountains. The 218-ha. (540-acre) tract is
located in Wasco County, Oregon, and is
administered by Bear Springs Ranger District
(Route 1, Box 65, Maupin, Oregon), Mount
Hood National Forest. The essentially square
area is located in sections 10 and 11, T. 6 S., R.
10 E., Willamette meridian, at 45°05' N. latitude,
and 121 °30' W. longitude (fig. PE-1).
ACCESS AND
ACCOMMODATIONS
The natural area is located along U.S.
Highway 26 about 35 km. (22 miles) southeast
of Government Camp and 40 km. (25 miles)
northwest of Warm Springs. The highway forms
the eastern boundary of the tract. Access is good
during both the summer and winter since snow is
removed
from
the
highway.
Public
accommodations are available at Government
Camp or Warm Springs; there are several
improved forest camps in the vicinity of the
natural area.
1
Description prepared by Dr. F. C. Hall, U.S.
Department of Agriculture, Forest Service, Region 6,
Portland, Oregon.
The Persia M. Robinson Research Natural
Area varies from approximately 850 to 950 m.
(2,800 to 3,100 ft.) in elevation. Topography is
undulating to rolling and is typical of lower
foothills on the east slope of the Cascade Range.
The bedrock is composed of basalts and
andesites, with andesitic flows probably predominant (Peck 1961).
A modified continental climate prevails.
Most precipitation occurs as snow during the
cool, cloudy winter. Summers are warm,
generally low in precipitation and largely
cloudless. One to 3 months of drought are
common. Unpublished climatic data collected at
Bear Springs Ranger Station located 5 km. (3
miles) north of the natural area are on file there.
No relevant published data are available.
Isohyetal maps suggest around 900 mm. (35 in.)
of annual precipitation.
Soils in the area have not been mapped.
Cursory examinations suggest aerially deposited
pumicite is commonly mixed with residual
materials.
BIOTA
Estimated areas by forest communities are:
Name
Area
The ponderosa pine-Douglas-fir stands can be
assigned to SAF forest cover type 214,
Ponderosa Pine-Larch-Douglas-Fir (Society of
American Foresters 1954) and Kuchler's Type
12, Douglas Fir Forest. Douglas-Fir grand fir
(Abies grandis) stands probably belong to SAF
type 213, Grand Fir-LarchDouglas-Fir and
Kuchler's Type 14, Grand
PE-l
Fir-Douglas Fir Forest. The tract is located
within the Pseudotsuga menziesii Zone found on the
eastern slopes of the Cascade Range in northern
Oregon and Washington (Franklin and Dyrness
1969).
Stand composition in this tract seems more
closely related to ground fire history than to site
variability (fig. PE-2). Stands currently
dominated or co-dominated by ponderosa pine
have minimal old-growth Douglas-fir. However,
Douglas-fir seedlings and saplings are abundant
and clearly dominate the smaller size classes;
some poles are also present. Incense-cedar
(Libocedrus decurrens) also occur occasionally. The
understory in these communities is dominated by
vine maple (Acer circinatum), Symphoricarpos albus,
and Ceanothus velutinus in the shrub layer and
pinegrass (Calamagrostis rubescens) and Pteridium
aquilinum in the herb layer. Most of the Ceanothus
is dead.
Douglas-fir-grand fir stands include occasional
old-growth ponderosa pine in the overstory.
Douglas-fir dominates the overstory and grand fir
the seedling, sapling, and pole size classes.
Western larch (Larix occidentalis) is sometimes a
common stand constituent. Where crown cover
of trees is dense, ground vegetation is minimal
and typically composed of vine maple and
Symphoricarpos,
pinegrass
with
occasional
Pteridium, and some forbs.
A list of mammals believed to utilize the
natural area as residents or transients is provided
in table PE-l.
HISTORY OF DISTURBANCE
Fire scarred ponderosa pine and western larch
record periodic ground fires which
PE-2
burned the area prior to initiation of fire control
programs about 1910. Lack of dominant oldgrowth grand fir and Douglas-fir in many
communities further indicate that many portions
of the tract have burned at some time.
Domestic livestock occasionally grazed the
tract between 1890 and 1945 when livestock
were removed from the general area. Cattle still
drift into the area occasionally from adjacent
lands. However, the natural area does not appear
to have been significantly affected by grazing.
RESEARCH
No research is known on the tract. The natural
area provides interesting opportunities to study:
(1) forest succession in the absence of ground
fires ; (2) biomass productivity in undisturbed
forest stands; and (3) stand structure and
development in natural stands. Comparisons are
possible with conditions on logged areas on
adjacent National Forest and Indian Reservation
land.
MAPS AND AERIAL
PHOTOGRAPHS
Special maps applicable to the natural area
include: Topography - 15' Mount Wilson, Oregon
quadrangle, scale 1:62,500, issued by the U.S.
Geological Survey in 1956; and geology - Geologic
Map of Oregon West of the 121st Meridian, scale
1:500,000 (Peck 1961). Either the District
Ranger (Bear Springs Ranger District) or Forest
Supervisor (Mount Hood National Forest) can
provide details on the most recent aerial photo
coverage of the area.
LITERATURE CITED
Franklin, Jerry F., and C. T. Dyrness
1969. Vegetation of Oregon and Washington.
USDA Forest Servo Res. Pap. PNW-80,
216 p., illus. Pac. Northwest Forest &
Range Exp. Stn., Portland, Oreg.
Kuchler, A. W.
1964. Manual to accompany the map of
potential natural vegetation of the
conterminous United States. Am.
Geogr. Soc. Spec. Publ. 36, various
paging, illus.
Peck, Dallas L.
1961. Geologic map of Oregon west of the
121st meridian. U.S. Geol. Surv. Misc.
Geol. Invest. Map 1-325.
Society of American Foresters
1954. Forest cover types of North America
(exclusive of Mexico). 67 p., illus.
Washington, D. C.
PE-3
Figure PE-2. -Natural features of Persia M. Robinson Research
Natural Area. Top: General view of forests along U.S.
Highway 26 with ponderosa pine overstory and understory of
Douglas-fir reproduction. Lower left: South slope community
of ponderosa pine and some Douglas-fir with understory of
vine maple, dead Ceanothus velutinus, Pteridium
aquilinum, and pinegrass. Lower right: Typical ponderosa
pine community found on east and north slopes with Douglasfir reproduction and ground cover of vine maple, Symphoricarpos albus, pinegrass, and forbs.