National Engineering and Environmental Laboratory (INEEL) occupies
2,300 km2 of sagebrush steppe on the eastern Snake
River Plain and is the largest of the few protected reserves of
this extensive vegetation type.
This publication documents the floristic diversity of the
area, describes its abiotic environment and common plant
communities, and summarizes our expanding knowledge of its
The INEEL lies
in the rainshadow of mountain ranges immediately to the west.
Mean annual precipitation is about 220 mm, and the scarcity
of water coupled with cold winters and hot, dry summers places
severe constraints on plant growth.
Nevertheless, the INEEL proper is home to some 400 species
of vascular plants. Compared
with areas that have a long history of livestock grazing, the
INEEL supports a rich diversity of native forbs.
Eighty-five percent of the species are natives, and
three-fourths of those are forbs.
vegetation of the INEEL typically consists of an overstory of
shrubs and an understory of grasses and forbs.
Big sagebrush (Artemisia
tridentata) is by far the most common shrub, but 43 other
species of shrubs have been recorded on the INEEL and the adjacent
Big Southern Butte. Perennial
grasses are the most abundant understory plants in shrub-dominated
communities and are the dominant plants in grassland communities
where shrubs are scarce. Ten
vegetation/cover classes are described and depicted on the
enclosed vegetation map.
Humans arrived on the eastern Snake
River Plain about 11,000 years ago.
Over 850 archaeological sites at the INEEL indicated a slow
but steady increase in the use of the area over that period.
The eastern Snake River Plain’s original inhabitants
likely were ancestors of the Plateau or Plains cultures who
migrated to the north or northeast during the Altithermal, a
period of gradual warming and drying during the early to mid
ancestors of the present-day Shoshone and Bannock migrated north
from the Great Basin proper as conditions became cooler and wetter
some 4,500 years B.P. Archaeological
sites in the region document continuity of the Shoshonean culture
from 4,000 years until historic times.
These native peoples primarily were hunters of large game,
so the major role of plants was to furnish habitat and food for
the animals that attracted the hunters to the area.
Direct use of plants by the aboriginal inhabitants is only
infrequently indicated by the archeological record, but the
artifacts found at one INEEL site, Aviator Cave, suggest a variety
of uses including foods, fiber, and fuel. Information on known and
potential uses of the region’s plants by Native Americans is
included in a summary table.
The fur trade, the Oregon Trail
(including Goodale’s Cutoff which crossed the southwest corner
of what is now the INEEL), and the establishment of Fort Hall all
impacted the natural ecosystems and aboriginal culture of the
eastern Snake River Plain in the early to mid 1800’s.
Bison were still numerous in the area in 1834, but numbers
declined rapidly thereafter.
The late 1800’s witnessed severe overgrazing by domestic
cattle and sheep throughout the Intermountain West, but the extent
to which native plant communities on the area now occupied by the INEEL
were impacted is unknown. Remnants
of trails and wagon
roads that were used, at least in part, for cattle and sheep
drives indicate that the area was grazed, but it may have been
used primarily as winter range. Federal legislation around the
turn of the century resulted in the construction of hundreds of
kilometers of canals in an effort to “reclaim” the desert, but
most of these were abandoned because they wouldn’t carry water.
During World War II, the U.S. Navy used several hundred
square kilometers of the present INEEL as gunnery and bombing
ranges. In 1949,
those ranges were coupled with a large parcel of land withdrawn
from the public domain to form the National Reactor Testing
Station. In 1974, the name was changed to the INEEL, and in
recognition of its importance as a field laboratory for ecological
research, the INEEL was designated as a National Environmental
Research Park in 1975. It
is an important reservoir of the biodiversity of sagebrush steppe