December 2012 Number 1 - Utah Native Plant Society

Calochortiana December 2012 Number 1
prohibiting genetic exchange with nearby populations,
leading to progressive differentiation in plant and animal
species now endemic to the area (Reveal 1980).
Reveal (1980) concluded that four of the endemic Ash
Meadows species (Astragalus phoenix, Mentzelia leucophylla,
Grindelia fraxinopratensis and Centarium
namophilum) are most closely related to congeners presently
found in montane portions of the Intermountain
Region. Their persistence to the present day is attributed
to successful adaptation to a more xeric environment,
the local persistence of water, and to relatively cool
temperatures created by cool air drainage from the surrounding
mountains (Beatley 1977, Reveal 1980).
Current-day vegetation at AMNWR is composed of a
typical Mohave creosote shrub vegetation community in
addition to emergent marshes, wet meadows, distinctive
spring complexes, alkaline desert uplands, and velvet
ash community assemblages, several of which are
known to exist only within the Refuge (Figure 2). These
vegetation communities provide habitat for several rare
and endangered plants, including endemic species, as
well as federally-listed fish and wildlife species (Bio-
West 2007).
CREATION OF THE REFUGE
Several legal and management documents led to the
establishment of AMNWR in 1984. Devil’s Hole National
Monument was declared by presidential proclamation
in 1953, and federal water rights for it were adjudicated
by the Supreme Court in 1976. The 1966 National
Wildlife Refuge System Administration Act provided
direction on Refuge management responsibilities
and guidance. The Endangered Species Act of 1973, as
amended, provided authority for appropriate protection
and management of federally listed species. The U.S.
Fish and Wildlife Service (USFWS) prepared a Warm
Springs Pupfish Recovery Plan in 1976, and a Devil’s
Hole Pupfish Recovery Plan in 1980. The Refuge was
established on 18 June, 1984 with the purchase of
12,654 acres of land from The Nature Conservancy.
The Refuge now occupies a total of 23,488 acres in
the Ash Meadows valley. Since designation, several
documents have guided Refuge management. The 1987
Ash Meadows Refuge Management Plan outlined general
principles for management of Refuge ecosystems
and listed species. The 1990 AMNWR Recovery Plan
for the Listed Species of Ash Meadows outlined recovery
needs for 12 listed species, and identified tasks to be
completed to recover and downlist or delist endangered
species (Sada 1990). In addition to the individual threatened
and endangered plants and animals of Ash Meadows,
the plan recognized the need for the recovery of
Ash Meadows habitats, processes and ecosystems. The
plan also included specific guidance on management
objectives (Sada 1990). In 2000, an Environmental Assessment
was completed (Otis Bay and Stevens Ecological
Consulting 2006).
ECOSYSTEM RESTORATION
Managers at AMNWR are seeking to restore impacted
wetland and desert upland habitats to conditions
that existed 100 years ago in an effort to promote endemic
species recovery. Large-scale ecosystem restoration
plans include impacted habitats in the Carson
Slough and Crystal Reservoir areas. Successful restoration
projects have been completed at Kings Pool in the
Point of Rocks area, and at Jackrabbit Spring, where
visitors can view desert pupfish (Bio-West 2008).
While the Refuge still supports a complex system of
important native communities, portions have been significantly
impacted by historic agricultural and mining
activities. Impacts have included peat mining in marshlands
surrounding Carson Slough in the 1960s and alfalfa
farming and cattle grazing in the 1970s. These activities
reduced discharge from all springs, and many
spring outflows were channelized (Sada 1984). A complex
irrigation system was constructed to support farming
efforts, and resulting agricultural impacts included
grading, cutting irrigation trenches, pumping spring
pools, and creating water holding areas such as Crystal
Reservoir (Otis Bay and Stevens Ecological Consulting
2006). Land disturbances created by farming and grazing
activities, as well as severe alteration of an ecosystem’s
hydrology, can cause considerable change in
vegetation community composition and allow for the
encroachment of weedy and non-native species (Fraser
and Martinez 2002).
Two of the most obvious chronic threats to AMNWR
species and ecosystems involve flow modification and
land conversion associated with former agricultural development
and invasive species. The most severe longterm
threat to the Refuge is potential future groundwater
extraction from the regional carbonate aquifer (Otis Bay
and Stevens Ecological Consulting 2006). Currently, the
Refuge is developing large-scale habitat restoration
plans for Carson Slough, Crystal Reservoir, and other
springs and areas around the Refuge. The proposed
plans consider the removal of the remaining irrigation
system and water control structures in an effort to restore
the hydrology and geomorphology of the Refuge
to a natural system. The hydrologic restoration will also
support vegetation community and wildlife habitat restoration
attempts. However, restoring an existing water
system that has supported an area for decades could
have unintended consequences.
Within the Refuge, impacts resulting from the historic
alterations to the landscape are evident both in the
extensive monocultures of salt cedar (Tamarix ramosis-
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