Page 26 - 2004 DT 9 Issues

Desert Pavement In the Mojave Desert, the U.S. ground, a process that can assist in heal-
Army’s National Training Center at Fort ing damaged pavements.
nterstate 15 bisects the heart of the Irwin, Calif. is a Rhode Island-sized com- Eric V. McDonald of the Desert
Mojave Desert. Miles of dry, sparsely plex that hosts war games for 10 months Research Institute in Reno, Nev. is in the
Ivegetated terrain ringed by distant, of the year. In places, the ground has been early stages of designing potential resto-
bare-rock mountains are interrupted here pounded into fine silt—equivalent to cen- ration projects for two Fort Irwin sites,
and there by a dirt road to Nowhere in turies of natural weathering—which gets applying different techniques to widely
Particular. Salt encrusted flats that once kicked up as dust, says Jayne Belnap, a different scenarios. These experiments
held life-giving water border the high- research ecologist at the U.S. Geologi- could lead to creating new pavement at
way. Eventually, a plume of dust rises in cal Survey (USGS) in Moab, Utah. the sites.
the distance, driven not by the wind, but Studies of the war-ravaged desert of Ku- With increased recreation and devel-
by a vehicle tearing down that anony- wait have documented the consequences opment pressures on our deserts,
mous dirt road or, perhaps, across the of such large-scale disruption. restoration efforts, no matter how
desert floor itself. Fort Irwin is “like Kuwait on accelerated, may never catch up.
Left undisturbed, much of the desert steroids,” says Robert H. Webb, a hy- Understanding the delicate mechanics of
floor will evolve slowly over centuries drologist with the USGS in Tucson, Ariz. the desert surface makes a “Leave no
to a hardened dark veneer of pebbles In the worst areas, it could take a cen- Trace” imperative all the more urgent.
overlying an otherwise stone-poor matrix tury to restore just the top 2.5 inches of
of silt, clay, and fine sand. Loose soil and soil to its previous consistency. Tracks March Board Notes:
fine-grained materials accumulate made in the 1940s by the single pass of a
through a process known as colluvation. tank are still evident today. Water seeps
Over time, larger rock fragments become into the ground in these tracks only half A motion was approved to rec-
displaced to the bottom layer and wind- as fast as undisturbed soil. ommend a $30,000 budget increase for
driven removal of surface dust and sand But surprisingly, four-wheel-drive member vote at the May 22, General
leaves the pebbled pickup trucks, meeting. The increase will be allocated
surface. Through driven for recreation to the Special Projects budget with the
these and other com- across the desert following proposed commitments:
plex processes, the floor, create four $15,000 - Wayside Sign Project;
th
surface is further times as much pave- additional $5,000 - 20 Anniversary ex-
transformed, smooth- ment-busting penses; $5,000 - improvements in Red
ing and refining away pressure as the tank, Rock Canyon; $5,000 - contingencies.
any trace of its origi- because the truck BLM Report:
nal topography. tire footprint is much Tim O’Brien reported that the
Desert pavements to- smaller than that of Senate Energy and Resource Committee
day cover as much as the tank tread. has unanimously approved making the
half of the world’s Peter K. Haff, a National Park Service Fee Program
arid lands. geologist at Duke permanent. While fee demo programs
Like cryptobiotic University, believes for the US Fish and Wildlife Service, US
soil crusts (see that recent field ex- Forest Service, and the Bureau of Land
Desert Trumpet, March 2004), desert periments to determine the mechanisms Management were not specifically in-
pavement creates an environmental sta- by which pavement is disrupted and re- cluded in this recommendation, it is very
bility, binding the thin underlying matrix paired may hold the key to at least partial likely that these entities will be included
with its fragile ecosystems of algae and restoration of the scarred desert. During in the final bill that will be sent to Con-
fungi. Unlike biological soils, it has few the creation process, medium-sized gress. The Fee Program for these will run
plant-nourishing qualities and is even less stones rise to the top layer and float atop through December 31, 2005, unless it is
tolerant of disruption. Raindrops, small a steadily accumulating sand base. After superceded by congressional approval
animals, foraging birds, even plant removing all surface stones from a small for permanent implementation.
growth, can dislodge the pebbles expos- area, Haff found that smaller surface There was no change in the
ing the subsurface material to damage. pebbles began to migrate across the total basic budget allotment for 2004

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