Nature Notes From Crater Lake
Volume 31, 2000
Research Natural Areas
By Steve Mark
As Aldo Leopold wrote, the first rule
of intelligent tinkering is to save all the pieces. That thought is the
rationale behind designation of research natural areas (RNAs) on
selected federal lands in the United States. RNAs are administratively
chosen (rather than legally created by Congress or a state legislature)
to promote scientific research. They serve a threefold purpose: 1) as
examples of significant ecosystems in a relatively undisturbed condition
for comparison with those influenced by human activities; 2) as sites
for scientific research as part of ecological and environmental studies;
3) as a reservoir of gene pools typical of endangered plants and
animals.

View of the Pumice Desert RNA. NPS photo,
Crater Lake Museum and Archives Collections.
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RNAs in Oregon fill one or more
"cells," a construct used to inventory, classify, and evaluate natural
areas. Cells are described in a natural heritage plan for the state and
contain one or more of the following ecosystem elements: plant
communities, special animal or plant species, aquatic types, other
natural features. As part of a statewide conservation strategy, 93 RNAs
have been designated in Oregon as of 1998. Four of those are located in
Crater Lake National Park, where a nomination process initiated by the
Nature Conservancy in 1986 eventually resulted in formal designation
with concurrence from the National Park Service.
The largest RNA within the park
consists of 3,055 acres and encompasses much of the Pumice Desert. All
of this RNA lies west of the road connecting Rim Drive with the North
Entrance, but is readily accessible to those visitors who stop at the
pullout containing a wayside exhibit. Anyone who makes a short walk will
find a largely barren area, one where infertile soil and severe
temperature extremes restrict the number of plant and animal species
residing in the Pumice Desert. This RNA nevertheless represents Oregon's
best example of two natural area cells, one being a lodgepole
pine/Brewer's sedge (Pinus contorta/Carex breweri) forest. The
other is subalpine pumice and ash fields, created by Mount Mazama's
climactic eruption that covered a former glacial valley some 7,700 years
ago.
Only 14 plant species have been
recorded in the Pumice Desert, so botanists are justified in describing
its flora as depauperate. Among the forbs, mountain buckwheat (Eriogonum
marifolium) and pussypaws (Spraguea umbellata) dominate,
though the comparatively rare Brewer's sedge is abundant in small
pockets. Despite the sparse vegetation, the Pumice Desert has attracted
scientists interested in studying physiological adaptations by plants to
harsh conditions. Another topic worth of further study is ecological
succession in the area, one illustrated by the slow encroachment of
lodgepole pine from the fringes of this seemingly desolate site.

Bitterbrush found in Desert Creek RNA.
Drawings by Charles F. Yocum in Shrubs of Crater Lake, (Crater
Lake Natural History Association, 1964), p. 29.
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If pumice and ash are defining
characteristics of the Pumice Desert, they are also abundant in the
park's second largest RNA. It is an area of 1,869 acres, extending some
two miles north and west of Sharp Peak. The closest vehicle access to
the Desert Creek RNA is by way of road #2308 on the Winema National
Forest, a route that approaches the so-called "golf course" from the
north. Hikers can proceed up the usually dry watercourse of Desert Creek
once they cross a fence whose purpose is to discourage cattle from
grazing in the park.
The few people who venture to Desert
Creek are attracted by the prospect of seeing a remnant plant community
dominated by bitterbrush
(Purshia tridentata), a shrub favored by the occasional pronghorn
antelope (Antilocarpa americana). The presence of bitterbrush
constitutes the main reason for this RNA because livestock grazing
elsewhere has so decimated these shrubs. Old growth ponderosa pine
(Pinus ponderosa) can be seen in the upland part of this RNA, mainly
because national park status for Crater Lake allowed these stands to
escape the almost universal practice of selective logging east of the
Cascades.
Llao Rock RNA not only lacks ponderosa
pine, it contains hardly any shrubs or wood rush. Thick pumice deposits
limit most of the understory to sedges in this area of 435 acres. Pumice
does support tree islands or "atolls," ones composed chiefly of mountain
hemlock (Tsuga mertensiana) and whitebark pine (Pinus
albicaulis). The latter can be found lining ridges or perched
precariously near the caldera's edge. Whitebark pine also represents the
cell filled by this RNA within the larger statewide plan, even if this
tree species is hardly unique to Llao Rock.
The RNA on Llao Rock was nominated
primarily to protect known populations of two rare plants. Botanists
once feared that the Crater Lake rock cress (Arabis suifrutescen
var. horizontalis)
might be extinct, but the Nature Conservancy relocated these wildflowers
while conducting its survey of potential RNAs in 1986. The other plant
is known as the pumice grapefern (Botrychium pumicola) or Oregon
moonwort, and can be found on level patches of course or "popcorn"
pumice in two locations on Llao Rock. As a tiny green plant growing so
close to the ground that it can be very difficult to see, the pumice
grape fern is vulnerable to trampling. Hiking in this RNA is not
prohibited, but please be careful where you step!
Access to the Llao Rock RNA is provided
by Rim Drive, with several pullouts located just east of North Junction.
Skiers will probably have an easier time of reaching the top than hikers
who have to contend with uneven footing due to holes created by Mazama
pocket gophers (Thomomys mazama). Wildflowers are relatively few,
though colorful; similar habitats such as Cloud Cap or Grotto Cove offer
easier access by vehicle.

Sundew in Sphagnum Bog. Photo by Willis Keithley,
1957.

Pumice grape fern. NPS photo, Crater Lake
Museum and Archives Collections.
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The wildflowers present in the park's
fourth RNA, 180 acres in vicinity of Sphagnum Bog, contrast markedly
from those found in areas dominated by dry pumice. Carnivorous sundews
and bladderworts most readily come to mind when pondering a visit to the
bog, but there is also a small population of the rare Mount Mazama
collomia (Collomia mazama) within this RNA. More noticeable to
the untrained eye are the pink and yellow monkeyflowers (Mimulus
lewisii and M. primuloides)
or the alpine shooting stars (Dodecatheon alpinum) that flower
around Crater Springs. In all, approximately one quarter of the 150
plant species counted within the Sphagnum Bog RNA could be classed as
wildflowers a number far exceeding the combined total of wildflower
species for Pumice Desert, Desert Creek, and Llao Rock.
What makes Sphagnum Bog exceptional,
however, is the diversity among its plant communities. In this respect
it outpaces other bogs or mires in the Oregon Cascades. Sphagnum Bog not
only contains eight plant communities, but the RNA also includes another
three communities delineated by forest type. Aquatic communities are
present at the springs, along streams, and in pooled water that is
isolated but sometimes deep. The mix of communities in this RNA allows
it to fill six cells identified by the Oregon's natural heritage plan as
needs in the west slope of the Cascade Range. These cells include
flowing and pooled springs, Sitka sedge (Carex sitchensis) fen,
Few flowered spikerush (Eleocharis pauciflora)/brown moss fen,
Bog laurel
(Kalmia microphylla) shrub swamp, Mountain alder (Alnus incana)/sedge
community, and Bog blueberry (Vaccinium occidentale) shrub swamp.
Although it is a wetland and therefore
fragile, Sphagnum Bog makes an interesting destination for a hike.
Several trails go there from locations inside the park, but the shortest
way is to take state highway 230 and turn east at the sign for National
Creek Falls. Use Rogue River National Forest road 6536 to go east, then
spur road 660 to find the trailhead that is only one quarter mile from
the park boundary. Anyone familiar with extended walking in dry
subalpine forest or through open pumice will appreciate the contrast
Sphagnum Bog offers.

Sphagnum Bog. NPS photo, Crater Lake Museum and
Archives Collections.
The RNA designation is not aimed at
enhancing recreational experience, but the casual visitor can
nevertheless gain some appreciation for how each of these areas might
contribute to current and future scientific study. Other localities in
the park have been focal points for notable botanical and ecological
investigations in the past, though areas like the Panhandle and Wizard
Island did not score as well in the Nature Conservancy's evaluation
process. Each place has its own peculiar characteristics, with some so
distinctive that they can serve as the standard from which to compare
various kinds and levels of tinkering.
Steve Mark is a National Park
Service historian who has served as editor of Nature Notes since
its revival in 1992.