Army's Compatible Use Buffer Program Partners Produce Conservation Plan to Ensure Continued Military Readiness Through Recovery of Candidate Species
Like many in the nation, the Fort Lewis Military Installation has become
a habitat island within a sea of development. Situated in the southern
Puget Lowlands of western Washington State, Fort Lewis provides
some of the largest expanses of remaining grassland habitat in the region.
The region's grasslands are threatened by incompatible human uses of the
land and the absence of fire across the landscape, resulting in encroachment of
conifers and non-native vegetation. Four species that occur on these rare grasslands
are federal candidates for listing under the Endangered Species Act (ESA):
the streaked horned lark, Mazama pocket gopher, Taylor's checkerspot, and mardon
skipper. If any of these species was to become listed, significant military training
restrictions could be imposed by the U.S. Fish and Wildlife Service.
Proactive Efforts: Supporting the Mission
Working proactively to ensure uninterrupted military training and readiness, Fort
Lewis has partnered with The Nature Conservancy, the Washington State Department
of Natural Resources, and the Washington State Department of Fish
and Wildlife to enact an Army Compatible Use Buffer (ACUB) program aimed at
recovery of the candidate species. Traditionally, ACUB program funding has been
used to purchase lands surrounding military installations to act as lifeboats for
rare species. At Fort Lewis, Army funds are being used instead for on-site land
management and habitat restoration. The non-military partners have provided
funds for land purchase and some management of off-post grassland sites. By initiating
restoration and reintroduction actions around Fort Lewis, the burden of
recovery is shared among the Army and other regional grassland land owners.
ACUB, along with other cooperative, regional conservation efforts, decreases the
likelihood that the candidate species will become listed under the ESA.
How We Work
The Fort Lewis ACUB Partners have cooperatively produced a five-year implementation
plan with conservation actions aimed at achieving the goal of continued
military readiness through recovery of candidate species. Projects are selected
by consensus of all partners and follow logical, temporally and spatially explicit,
species-specific strategies to achieve recovery. The conservation actions funded
through the Fort Lewis ACUB include land acquisition, habitat maintenance and
restoration, increasing the size and numbers of candidate species' populations,
monitoring, planning, and research.
Land Acquisition. The program has acquired privately-owned parcels containing
native prairie at various locations in the southern Puget Sound lowlands outside
Fort Lewis. The ACUB program and cooperators will continue to pursue additional
acquisitions of important habitat.
Habitat Restoration and Maintenance. To provide habitat for reintroduction of
candidate grassland species on ACUB lands, the land must be in suitable condition
to sustain those animals. Several first- and second-year projects focus on controlling
the invasive vegetation that prohibits occupation by the candidate species.
Two of the biggest non-native threats are Scotch broom, a nitrogen-fixing
shrub that modifies the structure of the prairie, creating unsuitable conditions for
native plants and animals, and turf-forming grasses, such as tall oatgrass and colocasenial bentgrass, that outcompete the native prairie bunchgrasses and forbs.
The partners are also working to enhance native vegetation on ACUB sites by
growing and outplanting native grasses and forbs that are important to the overall
structure and diversity of the grasslands and/or that fulfill specific requirements
of the candidate species (e.g., butterfly nectar sources).
Increasing the Size and Numbers of Candidate Species' Populations. The ACUB
program is funding captive rearing efforts for both candidate butterflies: the Taylor's
checkerspot and the mardon skipper. By developing methods to collect, rear,
and release these animals, we are moving toward the goal of reintroduction of
these species on currently unoccupied lands outside Fort Lewis. On those grasslands
where the candidate species occur, the above-described habitat restoration
activities are expected to increase the sizes of the populations.
Monitoring. Standardized, long-term monitoring is an integral aspect of the ACUB
program. The tracking of both habitat quality and species status is essential to
judge the effectiveness of land management activities, reintroductions, and species
status trends. To date, the program has funded work to assess habitat quality
ACUB lands, predict occurrence of the Mazama pocket gopher, and track population
size of Taylor's checkerspot and mardon skipper.
Planning and Research. Action plans are in development to direct conservation
and restoration activities on each ACUB property. The plans are essential to ensure
that funds are spent wisely, that conservation actions are targeted to specific
sites, and that conservation actions are implemented in a consistent and coordinated
manner across all ACUB lands.
Several important research projects have been initiated under the Fort Lewis
ACUB that will help inform and direct recovery actions. For instance, existing research
has shown that the streaked horned lark is subject to very high nest predation
rates, resulting in low reproductive success. However, the primary predators
are unknown. An ACUB-funded project is using remote sensing cameras on
streaked horned lark nests to identify predators and provide recommendations to
reduce nest predation rates.
Other research projects include habitat selection studies for both the Taylor's
checkerspot and mardon skipper. By identifying which habitat components these
animals are selecting for as egg-laying sites, as well as important life-history traits,
such as in which life-stage they spend the winter, we will better know how to create
and enhance their habitat.
A technical review panel comprised of scientists and biologists from the ACUB
partners and independent (non-ACUB) organizations reviews all project proposals
to ensure that a high standard of scientific integrity is maintained.
Eco-regional Efforts: The ACUB program and its associated management and
restoration projects are just one piece of a broad-scale, multi-partner effort to restore
and recover these candidate species on the grasslands throughout their historic
range. Efforts extend from the Georgia Basin in British Columbia, south
through the Puget Trough in Washington to the Willamette Valley in Oregon.
Partners in the south Puget Sound area, including the Washington Departments
of Fish andWildlife and Natural Resources, Fort Lewis, The Nature Conservancy,
Thruston County, and private landowners, have come together to sign a Candidate
Conservation Agreement (CCA). The CCA is a formal agreement among participating
partners and the U.S. Fish and Wildlife Service. The participants voluntarily
commit to implementing specific actions that will remove or reduce the
threats to these species, thereby contributing to stabilizing or restoring the species
so that listing is no longer necessary.
In addition to the formal agreements such as the CCA, partners are engaged in
local working groups throughout the eco-region, informal statements of unity that
link partners together through common goals, active participation in species-specific
workshops, as well as on-the-ground restoration and protection work across the
ecoregion. This cooperative approach boosts chances of regional recovery of the
species while assuring that Fort Lewis maintains its soldier training capacity.