Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition to List Astragalus anserinus, 46521-46542 [E9-21754]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 74, Number 174 (Thursday, September 10, 2009)]
[Proposed Rules]
[Pages 46521-46542]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-21754]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R1-ES-2009-0006]
[MO 922105 0082-B2]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition to List Astragalus anserinus (Goose Creek milkvetch) as 
Threatened or Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of a 12-month petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce our 
12-month finding on a petition to list Astragalus anserinus (Goose 
Creek milkvetch) as a threatened or endangered species under the 
Endangered Species Act of 1973, as amended (Act). After a thorough 
review of all available scientific and commercial information, we find 
that listing A. anserinus under the Act is warranted. However, listing 
is currently precluded by higher priority actions to amend the Lists of 
Endangered and Threatened Wildlife and Plants. We have assigned a 
listing priority number (LPN) of 5 to this species, because the threats 
affecting it have a high magnitude, but are non-imminent. Upon 
publication of this 12-month petition finding, A. anserinus will be 
added to our candidate species list. We will develop a proposed rule to 
list A. anserinus as our priorities allow. Any determinations on 
critical habitat will be made during development of the proposed rule.

DATES: The finding announced in this document was made on September 10, 
2009.

ADDRESSES: This finding is available on the Internet at https://www.regulations.gov at Docket Number FWS-R1-ES-2009-0006. Supporting 
documentation we used to prepare this finding is available for public 
inspection, by appointment during normal business hours at the U.S. 
Fish and Wildlife Service, Utah Field Office, 2369 West Orton Circle 
Suite 50, West Valley City, Utah 84119. Please submit any new 
information, materials, comments, or questions concerning this finding 
to the above address or via electronic mail (e-mail) at http://www.fw1srbocomments@fws.gov.

FOR FURTHER INFORMATION CONTACT: Larry Crist, Field Supervisor, U.S. 
Fish and Wildlife Service, Utah Field Office (see ADDRESSES)); by 
telephone at 801-975-3330; or by facsimile at 801-975-3331. If you use 
a telecommunications device for the deaf (TDD), call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.) requires 
that, for any petition containing substantial scientific and commercial 
information that listing may be warranted, we make a finding within 12 
months of the date of receipt of the petition on whether the petitioned 
action is: (a) Not warranted, (b) warranted, or (c) warranted, but 
immediate proposal of a regulation implementing the petitioned action 
is precluded by other pending proposals to determine whether species 
are threatened or endangered, and expeditious progress is being made to 
add or remove qualified species from

[[Page 46522]]

the Lists of Endangered and Threatened Wildlife and Plants. Section 
4(b)(3)(C) of the Act requires that we treat a petition for which the 
requested action is found to be warranted but precluded as though 
resubmitted on the date of such finding; that is, requiring a 
subsequent finding to be made within 12 months. We must publish these 
12-month findings in the Federal Register.

Previous Federal Actions

    On February 3, 2004, we received a petition dated January 30, 2004, 
from Red Willow Research, Inc., and 25 other concerned parties (the 
Prairie Falcon Audubon Society Chapter Board, Western Watersheds 
Project, Utah Environmental Congress, Sawtooth Group of the Sierra 
Club, and 21 private citizens) requesting that we list Astragalus 
anserinus as threatened or endangered, emergency list the species, and 
designate critical habitat concurrently with the listing (Red Willow 
Research Inc, in litt. 2004). We acknowledged the receipt of the 
petition in a letter to the petitioners in a letter dated February 19, 
2004. In that letter, we advised the petitioners that our initial 
review of the petition determined that emergency listing was not 
warranted, and that if conditions change we would reevaluate the need 
for emergency listing. We informed the petitioner that in light of 
resource constraints, we anticipated making our initial finding in 
Fiscal Year 2005 as to whether the petition contained substantial 
information indicating that the action may be warranted.
    On August 16, 2007, we published a notice of 90-day finding (72 FR 
46023) that the petition presented substantial scientific or commercial 
information indicating that listing A. anserinus may be warranted, and 
that we were initiating a status review of the species. For more 
information, refer to the 90-day finding that was published in the 
Federal Register on August 16, 2007 (72 FR 46023). We received 
information from the Bureau of Land Management, Idaho Department of 
Fish and Game, Red Willow Research Inc. (the petitioner), and the 
Cassia County Weed Control office in response to the 90-day finding. 
All information received has been fully considered in this finding.
    In accordance with the President's memorandum of April 29, 1994, 
Government-to-Government Relations with Native American Tribal 
Governments (59 FR 22951), Executive Order 13175, and the Department of 
the Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with the 
Tribes in developing programs for healthy ecosystems, to acknowledge 
that Tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to Tribes. In fulfilling our trust 
responsibilities for government-to-government consultation with Tribes, 
we met with the Shoshone Paiute Tribes regarding the process taken to 
conduct a 12-month status review of Astragalus anserinus. As an outcome 
of our government-to-government consultation, we recognize the strong 
cultural significance of A. anserinus to the Shoshone Paiute Tribes and 
acknowledge that in this 12-month finding. This notice constitutes the 
12-month finding on the January 30, 2004, petition to list A. anserinus 
as threatened or endangered.

Species Information

    Astragalus anserinus was first collected in 1982 by Duane Atwood 
from a location in Box Elder County, Utah, and subsequently described 
in 1984 (Atwood et al. 1984, p. 263). The species is known only from 
tuffaceous (ashy) soils found near Goose Creek on the Idaho, Nevada, 
and Utah border, an area approximately 20 miles (mi)(32.5 kilometers 
(km)) long and 4 mi (6.4 km) wide. A. anserinus is a low-growing, 
matted, perennial forb (flowering herb) in the pea or legume family 
(Fabaceae), with grey hairy leaves, pink-purple flowers, and brownish-
red curved seed pods (Mancuso and Moseley 1991, p. 4). This species is 
distinguished from A. calycosus (Torrey's milkvetch), A. purshii 
(woollypod milkvetch), and A. newberryi (Newberry's milkvetch), the 
three other mat-forming Astragalus species found in the Goose Creek 
drainage, primarily by its smaller leaflets and flowers, as well as the 
color and shape of the seed pods (Baird and Tuhy 1991, p. 1; Mancuso 
and Moseley 1991, pp. 4-5). In our August 16, 2007, 90-day finding (72 
FR 46023), we used the common name for the species, ``Goose Creek milk-
vetch.'' Here we use ``Astragalus anserinus'' for accuracy, and ``Goose 
Creek milkvetch'' (un-hyphenated) to make the taxonomy more consistent 
with today's botanical nomenclature.

Biology, Distribution, and Abundance

    Astragalus anserinus typically flowers from late May to early June. 
The species is assumed to be insect-pollinated, but the specific 
pollinators are unknown (Baird and Tuhy 1991, p. 3). Fruit set begins 
in early June with fruits remaining on the plants for several months. 
Mechanisms of seed dispersal are also unknown, but may include wind 
dispersion of seed pods and insect or bird agents (Baird and Tuhy 1991, 
p. 3). Because A. anserinus often grows on slopes and because the seed 
pods are found close to the ground below the vegetative portions of the 
plant, water or gravity dispersal may also be a dispersal mechanism. In 
2004 and 2005, clusters of seedlings were occasionally observed on 
abandoned ant hills, which could suggest some ant dispersal. Little 
scientific research specific to A. anserinus has been conducted beyond 
a basic species description and various survey efforts.
    Limited information is available regarding Astragalus anserinus 
longevity. In September 2004, the U.S. Bureau of Land Management (BLM) 
Field Office in Burley, Idaho (BLM-Idaho), permanently marked 10 
seedlings in a wash at the base of a tuffaceous outcrop (soils 
comprised of volcanic ash and particulates) at one site (Site 1), 8 
seedlings and 7 adults at the base of a slope at a second site (Site 
2), and 12 seedlings and 10 adults at a third site (Site 3) (A. 
Feldhausen, Burley BLM, in litt. 2007a, pp. 8-9). The results of this 
effort are summarized in Table 1 below. In a separate monitoring 
effort, BLM-Idaho conducted annual counting of A. anserinus individuals 
at two sites (Big Site 1 and Big Site 7) from 2004 to 2007. These 
results are depicted in Table 2 below. In combination, these two 
studies demonstrate large fluctuations in the number of individuals 
between years, with Table 2 reflecting almost a doubling or halving in 
magnitude between the numbers of individuals observed in successive 
years.

[[Page 46523]]



                 Table 1. Short-term tracking of Astragalus anserinus individuals (2004-2006) (A. Feldhausen, in litt. 2007a, pp. 8-9).
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                                             Site 1                              Site 2                                        Site 3
                Year                --------------------------------------------------------------------------------------------------------------------
                                            Seedlings               Seedlings                Adults               Seedlings                Adults
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2004                                 10 seedlings            8 seedlings             7 adults               12 seedlings           10 adults
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2005                                 4 dead, 2 small         6 dead, 1 small         1 dead, 6 alive        1 stake missing, 5     1 dead, 9 with
                                      seedlings (15 leaves    seedling (12 leaves),                          dead, 6 small adults   desiccated leaves
                                      each), 4 small adult    1 young adult                                  (3 with pods)          and numerous pods
                                      plants with pods
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2006                                 All 6 remaining plants                          Of the 7 remaining     Of the 6 remaining     7 dead, 3 stakes
                                      swept away by water                             adult plants, 2 dead   stakes: 1 stake        missing
                                      in a wash                                       and 5 alive            missing, 4 dead, 1
                                                                                                             adult
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  Table 2. Monitoring of Astragalus anserinus at two sites in Idaho (A.
   Feldhausen, in litt. 2007a, pp. 8-9; Idaho Conservation Data Center
              (IDCDC) 2007a, Element Occurrence (EO) 003).
------------------------------------------------------------------------
              Year                    Big Site 1          Big Site 7
------------------------------------------------------------------------
2004                              123 total (2 dead,  138 total (42
                                   73 seedlings, 48    seedlings, 96
                                   adults)             adults)
------------------------------------------------------------------------
2005                              136 total (8 dead,  67 total (3 dead,
                                   13 seedlings, 115   6 seedlings, 58
                                   adults)             adults)
------------------------------------------------------------------------
2006                              88 total            135 total
------------------------------------------------------------------------
2007                              73 total            69 total
------------------------------------------------------------------------

    These wide-ranging fluctuations in the number of Astragalus 
anserinus individuals observed suggests that the species is either 
short-lived or that adult plants may remain dormant during some growing 
seasons. If the species is short-lived, corresponding augmentation of 
seedlings to replace lost individuals would be expected; however, this 
has not been observed. During spring census efforts, seedlings (defined 
as young developing plants having 3 or fewer leaves) made up 1,433 of 
the 30,281 individuals that were counted in 2005 (4.7 percent), and 167 
of the 4,087 individuals counted in 2008 (4.1 percent) (Service 2008a, 
p. 1). The definition of seedlings used for purposes of Table 2 is 
different than that used in the 2004, 2005, and 2008 census efforts; 
with seedlings in Table 2 being defined by young developing plants with 
cotyledons (the first leaves to emerge from the ground) present. 
Seedlings made up 59.3 percent of the total individuals at Big Site 1 
in 2004, and 9.6 percent of the total individuals in 2005. Seedlings 
also made up 30.4 percent of the total individuals at Big Site 2 in 
2004, and 8.9 percent of the total individuals in 2005 (J. Tharp, 
Burley BLM, in litt., 2008a, p. 1). Although we have no direct 
information on A. anserinus seedling germination, it would likely be 
more or less abundant depending on the time of year sampled. We expect 
spring would be the most likely time to observe A. anserinus seedlings, 
like many other plants, and the seedlings could be more numerous in 
years when climatic conditions are more amenable to their germination 
and establishment. One such climatic factor could be annual 
precipitation; the amount and timing of this precipitation over the 
course of a year could influence seed germination and seedling 
recruitment.
    During field surveys, several smaller Astragalus anserinus plants 
were partially excavated and observed to be attached to large woody 
roots. Parts of some individual plants frequently appeared to be dead, 
with only a small green portion remaining. This suggests that 
vegetative growth may vary during successive years, and that plant size 
may not necessarily correspond to the age of the individual. This also 
suggests that some A. anserinus individuals may remain dormant for an 
entire growing season. In at least one other species of Astragalus (A. 
ampullarioides), adult plants can exhibit dormancy (an inactive state) 
during a growing season, and the perennial rootstock allows the plant 
to survive dry years (Van Buren and Harper 2003b in Service 2006a, p. 
8). However, monitoring studies to determine whether A. anserinus also 
has this ability have not been conducted.
    Table 2 also demonstrates that fluctuations in the number of 
Astragalus anserinus individuals can vary across sites during a given 
year. For example, the number of individuals counted at Big Site 1 
decreased from 136 to 88 between 2005 and 2006, whereas the number of 
individuals counted at Big Site 7 increased from 67 to 135 during the 
same time period. However, between 2006 and 2007, the number of 
individuals counted at Big Site 1 decreased from 88 to 73 and the 
number of individuals counted at Big Site 7 decreased 135 to 69. Since 
these sites are approximately 0.5 mi (0.8 km) apart on similar aspects, 
this suggests that local weather patterns may not be a predominant 
factor influencing plant abundance and annual survival.
    Although we acknowledge there are some uncertainties with regard to 
longevity, plant dormancy, and the effect of climatic factors on A. 
anserinus, the observed population trend has been a decrease in the 
number of observed individuals.
    Astragalus anserinus is endemic to the Goose Creek drainage in 
Cassia County, Idaho; Elko County, Nevada; and Box Elder County, Utah. 
The Goose Creek drainage occurs within the Great Basin ecosystem; this 
drainage receives an annual rainfall average of less than 12 inches (30 
centimeters). Element Occurrences (EOs) are areas where a species was 
or is recorded to be present. The known EOs of A. anserinus occur at 
elevations ranging between 4,900 to 5,885 feet (ft) (1,494 to 1,790 
meters (m)) (Idaho Conservation Data Center (IDCDC) 2007b, p. 2; Smith 
2007, Table 1). Most A. anserinus EOs are within an approximate 20-mi 
(32-km) long by 4-mi (6.4-km) wide area, oriented in a southwest to 
northeasterly direction along Goose Creek. However one A. anserinus EO 
has been documented outside of the Goose Creek watershed approximately 
2 mi (3.2 km) south of any other EOs. The geographic range of the 
species has not been extended from that presented in the 90-day finding 
(72 FR 46023; August 16, 2007). Based on new information from surveys

[[Page 46524]]

conducted in Nevada in 2006, during which several new EOs were 
discovered, gaps in the range have been filled with the 6 new EOs 
extending toward the 1 EO outside of the Goose Creek drainage.
    Astragalus anserinus occurs in a variety of habitats, but is 
typically associated with dry tuffaceous soils from the Salt Lake 
Formation that have a silty to sandy texture (Mancuso and Moseley 1991, 
p. 12). In Utah, soil series where A. anserinus has been located 
include Bluehill fine sandy loam, Codquin gravelly sandy loam, 
Cottonthomas fine sandy loam, and Tomsherry fine sandy loam (Hardy 
2005, p. 4). The species has been observed growing on steep or flat 
sites, with soil textures ranging from silty to sandy to somewhat 
gravelly. These habitats can vary from stable areas with little erosion 
to washes or steep slopes where erosion is common. It appears that the 
species tolerates, and may proliferate with, some level of disturbance, 
based on its occurrence on steep slopes where downhill movement of soil 
is common, within eroded washes, and along road margins and edges of 
cattle trails. However, individuals have not been observed where 
vehicle or livestock travel is frequent or where water flows through 
washes on a regular basis.
    Astragalus anserinus is generally not found on north-facing slopes, 
but is found on most other slope aspects within sparsely vegetated 
areas in sagebrush and juniper habitats. The estimated total plant 
cover (of all species) at sites where A. anserinus occurs is between 10 
and 35 percent (Hardy 2005, p. 4; Smith 2007, p. 2). The dominant 
native species within the general surrounding plant community include 
Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush), 
Juniperus osteosperma (Utah juniper), Chrysothamnus viscidiflorus 
(green or yellow rabbitbrush), Poa secunda (Sandberg's bluegrass), and 
Hesperostipa comata (needle and thread grass). A. anserinus is 
frequently associated with a suite of native species that reside on the 
tuffaceous sand (Baird and Tuhy 1991, pp. 2-3) including: Achnatherum 
hymenoides (Indian ricegrass), Chaenactis douglasii (Douglas' 
dustymaiden), Cryptantha humilis (roundspike cryptantha), Eriogonum 
microthecum (slender buckwheat), Eriogonum ovalifolium (cushion 
buckwheat), Ipomopsis congesta (= Gilia congesta; ballhead gilia), 
Mentzelia albicaulis (whitestem blazingstar), and Phacelia hastata 
(silverleaf phacelia). Several nonnative species also co-occur with A. 
anserinus (see Nonnative Introduced Species under Summary of Factors 
Affecting the Species Rangewide: Factor A, below). Another Goose Creek 
drainage endemic, Penstemon idahoensis (Idaho penstemon), is found near 
A. anserinus, but these species are seldom found immediately adjacent 
to one another. Other sensitive species in the area include Arabis 
falcatoria (= Boechera falcatoria; falcate rockcress), and Potentilla 
cottamii (Cottam's cinquefoil) (Franklin 2005, pp. 9-10, 159-160).
    The Heritage/Conservation Data Center programs in Idaho, Nevada, 
and Utah rank Astragalus anserinus as a G2 species, indicating the 
species is ``imperiled throughout its range because of rarity or other 
factors that make it vulnerable to extinction,'' and S1 (critically 
imperiled) in the three states (IDCDC 2007b, p. 2). Heritage/
Conservation Data rankings do not offer any sort of protection, but are 
often used to guide other agencies and entities in designating 
sensitive species. The BLM has assigned different status designations 
to the species in the three states where it occurs. In Idaho, A. 
anserinus is designated as a type 2 species, which reflects a rangewide 
or globally imperiled species with a high endangerment status. In Utah, 
the species is designated as a sensitive plant species (Fortner 2003 in 
Franklin 2005, p. 17), and in Nevada the species is designated as a 
special status species (Morefield 2001, p. 1). BLM policy provides that 
species which are designated as a ``sensitive species'' shall be 
protected as candidate species for listing under the Act (BLM 2001, p. 
06C1).
    Astragalus anserinus is currently known from 19 EO records (5 in 
Idaho, 10 in Nevada, and 4 in Utah) (IDCDC 2007b, p.4; Smith 2007, p. 
1; Utah Conservation Data Center (UCDC) in litt. 2007, map; Service 
2008b, 17 pp.). The number of currently known EOs (19) differs from the 
24 EOs identified in the 90-day finding published on August 16, 2007 
(72 FR 46023). Recently published NatureServe guidelines for 
designating EOs in Idaho and Utah (IDCDC 2007b, p. 1; R. Fitts, Utah 
Conservation Data Center, in litt. 2008, p. 1) state that sites 
(occupied points, lines, or polygons) that occur within 0.6 mi (1 km) 
of each other are within the same EO. Accordingly, several occupied 
sites that were designated as individual EOs in our August 16, 2007, 
90-day finding were combined. In addition, six new EOs were discovered 
in Nevada as a result of survey efforts in 2006. We developed a naming 
convention to help us manage and compare EO data for recently 
consolidated sites before and after implementation of the NatureServe 
guidelines. For example, the designation U001-4-17 identifies Utah EO 
001, which was previously identified as Utah EO 004. The suffix 17 
reflects a site number that has been assigned according to the sequence 
the site was counted in 2004 or 2005. We use our naming convention as 
described, as well as EO number in various places throughout this 
finding, depending on the context of the particular site being 
referenced.
    The majority of Astragalus anserinus sites in Idaho, Utah, and 
Nevada occur on Federal lands managed by the BLM (Service 2008, 17 
pp.). In 2004 and 2005, we conducted a multiagency census and survey 
effort for A. anserinus with the BLM, USFS, and natural resource 
agencies from the States of Idaho, Nevada, and Utah. Our objective was 
to count (census) known sites, survey additional areas, and document 
any new populations. In 2004, we examined 33 sites in 5 EOs in Idaho 
(3,467 individuals were counted); 6 sites in 3 EOs in Nevada (2,252 
individuals were counted); and 11 sites in 2 EOs in Utah (7,558 
individuals were counted) (Service 2008, 17 pp.). In 2005, we examined 
5 sites at 1 EO in Nevada (3,074 individuals were counted), and 64 
sites in 1 EO in Utah (27,207 individuals were counted) (Service 2008, 
17 pp). During the 2004 and 2005 census efforts, 40,858 individual 
plants of the estimated 60,000 individual plants range-wide (68 
percent) were counted at 119 sites in 12 EOs.
    Estimating the total Astragalus anserinus population size is 
complicated because of the variability in the species annual abundance, 
and the different census and survey methods that have been employed. 
For example, plant abundance at one site in Idaho over a 4-year period 
varied significantly: 138 plants were counted in 2004; 67 plants in 
2005; 135 plants in 2006; and 69 plants in 2007 (Service 2008, 17 pp.). 
Census efforts in 2008 at 3 sites that were not affected by a 
significant wildfire in 2007 demonstrated a general decrease from plant 
counts when compared to the 2004 or 2005 data; 1 site increased by 5.4 
percent (652 to 687), 1 site decreased by 76.3 percent (1,458 to 346), 
and 1 site decreased by 79.0 percent (3,081 to 647) (Service 2008c, 
Table 2). Using the best available data for each A. anserinus site, we 
estimate that there were approximately 60,000 individuals distributed 
across the three states prior to the 2007 wildfires (Service 2008, 17 
pp.). However, we recognize the inherent variability associated with

[[Page 46525]]

estimating population size, because of large fluctuations observed 
between successive monitoring years and the differing census and survey 
methods that have been employed. Generally, the 2004 and 2005 census 
counts yielded higher numbers than had been estimated by previous 
surveys (Service 2008, pp. 1-6), however, monitoring efforts have not 
occurred regularly enough or over a long enough period to allow us to 
statistically analyze population trends.
    Based on pre-2007 (pre-wildfire) individual plant count data, 
approximately 10 percent of all known Astragalus anserinus individuals 
occur in Idaho (5,500 plants), 25 percent occur in Nevada (15,500 
plants), and 65 percent occur in Utah (39,000 plants) (Service 2008c, 
Table 1). State-specific information on the population status of A. 
anserinus is described below.

Idaho

    Prior to 2004, seven EOs (which are now combined into four EOs 
under the NatureServe guidelines) were monitored by the IDCDC, who 
reported the number of Astragalus anserinus individuals at most sites 
as estimations. The first A. anserinus EO was documented in 1985 (1 
year after the species was described (Atwood et al. 1984, p. 263)), but 
systematic or comprehensive surveys were not conducted in Idaho until 
1991 (Mancuso and Moseley 1991, p. iii). In 1991, the A. anserinus 
population in Idaho was estimated at over 914 individuals (Mancuso and 
Moseley 1991, pp. 2, 13-14).
    During the 2004 census effort, the four known Astragalus anserinus 
EOs in Idaho were revisited and three new sites were located (two sites 
were within an existing EO and one new site was considered to be a new 
EO). In total, 5,052 A. anserinus individuals were counted, with 2,460 
of these individuals observed within the original 4 Idaho EOs (Service 
2006b, Table 1). Based on pre-2007 EO revisions, census data from 2004 
indicated: (a) stable plant numbers at four EOs; (b) an increase in 
plant numbers at one EO (compared to pre-2004 survey numbers); and (c) 
an unknown change at two EOs (participants were unable to conduct a 
complete census because part of the EOs are on private property) 
(Service 2006b, Table 1). However, because of the different survey 
methodologies employed before 2004, it is difficult to conclusively 
compare survey and census results or estimate long-term population 
trends for A. anserinus in Idaho (Service 2006b, Table 1).
    In 2007, the IDCDC standardized its methodology for designating 
Astragalus anserinus EOs to conform to the above referenced NatureServe 
guidelines. Under the new methodology, the four existing EOs and the 
three new sites found in 2004 were combined into five EOs (EOs 1, 6 and 
7 were deleted and added to EO 3; EO 9 was added as a new EO (IDCDC 
2007b, p. 4)). The IDCDC methodology also ranks the health of the EOs 
based on a weighted formula made up of three elements: EO size (33 
percent); EO condition (based on the abundance of native plants, 
introduced plants, and anthropogenic disturbance) (33 percent); and EO 
landscape context (based on the degree of habitat fragmentation) (33 
percent). Rankings are categorized from A through D, with ``A'' ranked 
EOs generally representing higher numbers of individuals and higher 
quality habitat, and ``D'' ranked EOs generally representing lower 
numbers of individuals and lower quality (or degraded) habitat. Under 
this ranking system, the IDCDC assigned an ``A'' ranking to one EO, 
``B'' rankings to two EOs, and ``C'' rankings to two EOs (IDCDC 2007b, 
p. 4).
    Monitoring efforts and results in Idaho that have been used to 
inform this status assessment for Astragalus anserinus include: (a) the 
collection of plant community data and establishment of photo-points in 
2000 and 2001 at 3 sites (Mancuso 2001a, pp. 8-9; Mancuso 2001b, p. 2); 
(b) census efforts at all Idaho EOs on public land in 2004 (Service 
2008b, 17 pp.); (c) conducting annual census efforts at 2 sites in 
Idaho since 2004, as summarized in Table 2 above (A. Feldhausen, in 
litt. 2007a, pp. 8-9; IDCDC 2007a, EO 003); (d) the permanent marking 
and monitoring of A. anserinus individuals at 3 sites from 2004 to 2006 
as summarized in Table 1 (A. Feldhausen, in litt. 2007a, pp. 8-9); and 
(e), establishing A. anserinus - Penstemon idahoensis - Euphorbia esula 
(leafy spurge) control study plots at 11 sites in 2007 by BLM-Idaho (A. 
Feldhausen in. litt. 2007a, p. 3).

Nevada

    Astragalus anserinus surveys in Nevada were first conducted in 1991 
and 1992, resulting in the documentation of 4 EOs, with an estimated 
plant abundance of 827 individuals (Morefield 2001, p. 1). Subsequent 
census efforts in 2004 and 2005 failed to locate any new sites until 
2006, when 6 new EOs with approximately 11,000 individuals were 
discovered. The 6 new EOs represent 18.3 percent of the estimated 
range-wide population total of 60,000 individuals (Service 2008b, 17 
pp.). There are presently ten known EOs in Nevada, as documented by the 
Nevada Natural Heritage Program (NNHP) (Smith 2007, p. 1). Site visits 
to 4 EOs were conducted during the 2004 and 2005 census efforts, and 
4,930 A. anserinus individuals were counted. However, because of the 
different survey methodologies employed prior to 2004, it is difficult 
to conclusively compare survey and census results or estimate long-term 
population trends for the species in Nevada (Service 2006b, Table 1). 
In 2008, we counted individuals at two sites during our post-2007 
wildfire assessment study, including EO 001 (which partially burned), 
and site 1 of EO 004 (which did not burn). We observed that the number 
of individuals in EO 001 decreased by 68 percent, while the number of 
individuals in EO 004 increased by 5.4 percent (Service 2008c, Table 2) 
(see the discussion under Wildfire below for further details on the 
2008 study).
    Monitoring efforts and results in Nevada that have been used to 
inform this status assessment include census efforts conducted in 2004 
and 2005 at four EOs (Service 2008b, 17 pp.), and post-wildfire census 
efforts in 2008 at two EOs (one that partially burned, and one that did 
not burn) (Service 2008c, Table 2, Map 2).

Utah

    There were 9 known Astragalus anserinus EOs in Utah with an 
estimated 7,617 individuals, based on the results of initial surveys 
conducted in 1990 and 1991 (Baird and Tuhy 1991, p. 2; Morefield 2001, 
p. 1). Eight of these EOs were documented by the UCDC, and one EO was 
documented in the Nevada Natural Heritage Program database, although it 
was not reflected in the UCDC database (Mancuso and Moseley 1991, p.2). 
There were additional Utah surveys in 1993 (Hardy 2005, p. 4), however 
we do not know whether they were resurveys of known sites and do not 
believe the results are included in the UCDC database. The BLM Salt 
Lake City, Utah field office (BLM-Utah) staff indicates that they are 
aware of data from at least one additional site that has not been 
submitted to the UCDC (Hardy 2005, p. 4). In addition, surveys were 
conducted in Utah by BLM in 2000, 2001, and 2004 to evaluate the 
environmental effects of a waterline and livestock water tank 
construction project to the species (Hardy 2005, p. 5); no sensitive 
plants were discovered along the proposed water line.
    Site visits conducted to what was then 6 known EOs, and 1 new site 
during 2004 and 2005 census efforts recorded a total of 33,476 
Astragalus

[[Page 46526]]

anserinus individuals, although only partial plant counts were 
conducted at 3 of the 6 known EOs. Two other documented EOs that had 
the greatest numbers of individuals weren't counted during the 2004 and 
2005 census efforts because of limitations on access and time 
constraints (Service 2006b, Table 1). The 2004 and 2005 census data 
indicated higher A. anserinus count numbers than the previous estimates 
at five of the known EOs. However, because of the different survey 
methodologies that were used before 2004, we are unable to conclusively 
compare survey and census results or estimate long-term population 
trends for the species in Utah (Service 2006b, Table 1).
    In early 2007, the UCDC reconfigured Astragalus anserinus EOs in 
Utah to conform to the general EO standards guidebook, IDCDC 
methodology, and NatureServe guidelines, resulting in the combining of 
the nine previously documented EOs into four EOs (R. Fitts, in litt. 
2008). Based on 2005 census estimates, the largest Utah EO (EO 001) 
supported over 37,000 plants, making up over 60 percent the known 
individuals range-wide (Service 2008b, 17 pp.).
    In 2008, re-census efforts were conducted as part of a post-
wildfire assessment at ten sites in Utah where we had information on 
the number of individuals from 2004 or 2005 surveys. We surveyed two 
sites that did not burn, four sites that were partially burned, and 
four sites that were completely burned. At the 2 sites that did not 
burn, the individual numbers of plants decreased by 76.3 percent and 79 
percent. At the 4 sites that partially burned, the individual numbers 
of plants decreased by 34.9 percent, 89.7 percent, 91.1 percent, and 
92.6 percent. The individual plant counts at the 4 sites that 
completely burned decreased by 94.9 percent, 98.1 percent, 98.2 
percent, and 100 percent (Service 2008c, Table 2) (see the Wildfire 
discussion under factor A, below, for further information on the 2008 
post-wildfire assessment efforts).
    Monitoring efforts and results in Utah that have been used to 
inform this status assessment include: (a) census efforts conducted in 
2004 and 2005 at portions of 2 EOs (Service 2008b, 17 pp.); (b) 
installation of 4 small chicken-wire exclosure cages over 5 individual 
plants in 2004 to monitor effects of a waterline construction project 
(all individuals were still present in 2007) (Hardy 2008, pp. 1-2); (c) 
documentation of 2 individual plants within a 300-foot long belt 
transect in 2006 (scheduled to be resurveyed in 2010 (Hardy 2008, p. 
2)); (d) establishing a study plot in 2007 near a waterline constructed 
in 2004 that includes 231 A. anserinus individuals, which may be fenced 
in the future (Hardy 2008, p. 1); and (e) conducting field 
inspectionsat 10 sites during the 2008 post-wildfire re-census effort 
(Service 2008c, Table 2, Map 2).

Summary of Factors Affecting the Species Rangewide

    Section 4 of the Act (16 U.S.C. 1533) and implementing regulations 
at 50 CFR 424, set forth procedures for adding species to the Federal 
Lists of Endangered and Threatened Wildlife and Plants. Under section 
(4) of the Act, we may determine a species to be endangered or 
threatened based on any of the following five factors: (A) The present 
or threatened destruction, modification, or curtailment of habitat or 
range; (B) overutilization for commercial, recreation, scientific, or 
educational purposes; (C) disease or predation; (D) the inadequacy of 
existing regulatory mechanisms; or (E) other natural or manmade factors 
affecting its continued existence. In making this finding on a petition 
to list Astragalus anserinus, information regarding the status of, and 
threats to, A. anserinus in relation to the five factors provided in 
section 4(a)(1) of the Act is discussed below.

Factor A. The Present or Threatened Destruction, Modification, or 
Curtailment of Its Habitat or Range

Wildfire

    Organisms adapt to disturbances such as historical wildfire regimes 
(fire frequency, intensity, and seasonality) with which they have 
evolved (Landres et al. 1999, p. 1180), and different rare species 
respond differently to wildfire (Hessl and Spackman 1995, pp. 1-90). In 
general, fire regimes within forest and steppe habitats in the western 
United States have been highly disrupted from historical patterns 
(Whisenant 1990, pp. 4-10; D'Antonio and Vitousek 1992, pp. 63-87; 
Weddell 2001, pp. 1-24). In some instances, fire suppression has 
allowed grasslands to be invaded by trees (Burkhardt and Tisdale 1976, 
pp. 472-484; Lesica and Martin 2003, p. 516), and in many grassland and 
shrub habitats, fire frequencies have increased due to the expansion 
and invasion of annual nonnative grasses (Whisenant 1990, pp. 4-10; 
D'Antonio and Vitousek 1992, pp. 63-87; Hilty et al. 2004, pp. 89-96). 
These invasive annual nonnative grasses become established in 
unvegetated areas that would normally separate native vegetation, 
dramatically increasing the ability of wildfire to spread.
    Our understanding of the historical wildfire regime in the Goose 
Creek drainage, and specifically within Astragalus anserinus habitat, 
is limited. In general, the average wildfire return interval within the 
sagebrush-steppe ecosystem as a whole has been reduced from between 60 
and 110 years, to often less than 5 years (Whisenant 1990, p. 4; Wright 
and Bailey 1982, p. 158; Billings 1990, pp. 307-308; USGS 1999, pp. 1-
9; West and Young 2000, p. 262). Recent wildfires often tend to be 
larger and burn more uniformly across the landscape, leaving fewer 
unburned areas, which can affect the post-fire recovery of native 
sagebrush-steppe vegetation (Whisenant 1990, p. 4; Knick and Rotenberry 
1997, pp. 287, 297; Brooks et al. 2004, pp. 682-683). The result of 
this altered wildfire regime has been the conversion of vast areas of 
sagebrush-steppe ecosystem into nonnative annual grasslands (USGS 1999, 
pp. 1-9). The proportion of annuals in the sagebrush-steppe ecosystem 
increases dramatically at higher fire frequencies, while all other 
vegetative life forms decrease. Sagebrush can reestablish from seed 
following fire, however the seeds are short-lived and if a second fire 
occurs before the new plants produce seed (4 to 6 years), the species 
may face local extirpation. This would be less of a problem if the 
fires occurred over relatively small areas, because seed from adjacent 
unburned areas would be naturally transported back into burned areas. 
As fires become larger, the opportunity for seed migration into burned 
areas is dramatically decreased (Whisenant 1990, p. 8-9). Based on our 
observations, Astragalus anserinus seedling germination does not appear 
to be stimulated by wildfire. Accordingly, fewer individuals and fewer 
seeds would be available for recruitment if wildfire were to return 
before the species is able to recover from earlier wildfire impacts to 
the population. As a result, there would be a corresponding decline in 
the overall number of individuals.
    Wildfire was not documented within Astragalus anserinus habitat 
prior to 2000 (A. Feldhausen, in litt. 2007, p. 3; R. Hardy, Salt Lake 
City BLM, in litt. 2008, p. 1), although undoubtedly they occasionally 
occurred in the past. Astragalus anserinus habitat is normally sparsely 
vegetated (e.g., typically 10 to 30 percent total vegetative cover), 
which likely makes it less vulnerable to wildfire because of the lack 
of fuels to sustain fire over large areas. We are aware of a wildfire 
that occurred in A.

[[Page 46527]]

anserinus habitat in Idaho in 2000, and another wildfire that occurred 
in Nevada and Utah in 2007. The 2000 Idaho wildfire affected two EOs 
(EO 007 and EO 009), however at the time, EO 009 had not been 
documented and A. anserinus was not affected by the 2000 wildfire at EO 
007 (A. Feldhausen, in litt. 2007a, p. 11). Accordingly, before 2008, 
we had no pre-wildfire data with which to assess the impact of 
wildfires on A. anserinus. Our knowledge of the effects from wildfire 
was limited to observations at EO 009 from 2004. Based on the best 
available information, EO 009 is made up of 3 separate occupied sites 
that contain 10, 36, and 749 individuals based on 2004 surveys/census 
efforts. The EO 009 site with 749 individuals is within a sparsely 
vegetated slope with mature junipers and shrubs, and may not have 
burned during the 2000 wildfire.
    Based on pre-fire data, a single wildlfire in 2007 in Nevada and 
Utah completely burned 3 EOs and portions of 5 other EOs containing 
approximately 53 percent of all known Astragalus anserinus individuals 
(31,500 of 60,000 individuals). The 2007 wildfire also burned 25 
percent of the known occupied habitat (100 acres (ac) (41 hectares 
(ha)) out of an estimated 400 ac (164 ha)) (Service 2008c, Table 1).
    In Nevada, 3 EOs were completely within the burned area footprint 
(1,512 total individuals), and three other EOs were partially burned, 
but had an estimated loss of approximately 72 percent of the 
individuals within those 3 EOs (5,394 of 7,508 individuals). In Utah, 
portions of two EOs were burned in the wildfire (EOs 001 and 009). The 
wildfire in EO 001, which contained more than 60 percent of the known 
individuals (37,000 of 60,000 individuals), was estimated to have 
burned approximately 40 percent of the known individuals (24,000), and 
approximately 18 percent of the total occupied acreage (71 ac (29 ha)) 
(Service 2008b, 17 pp.). Please note that since six of the 10 currently 
known EOs in Nevada were not discovered until 2006 (EOs 005 through 
010), and only population estimates and point data have been collected, 
the total number of individuals and the acreage affected by the 2007 
wildfire are only estimates. Estimating the number of individuals and 
acres with greater precision is difficult because of the various 
methods that have been employed by prior survey and census efforts.
    Based on initial field visits and reports following the 2007 
wildfire (Howard 2007, pp. 1-2), we initially understood that the 
wildfire burned intensely and almost continuously across the landscape. 
However, our 2008 field inspection determined that the wildfire burned 
as a mosaic rather than continuously, and did not affect some small 
patches of Astragalus anserinus occupied habitat. We observed that 21.3 
percent, 81.1 percent, and 94.6 percent of the total acreage was burned 
at 3 A. anserinus sites, however estimates were not made for 2 other 
sites within the burned area perimeter that were only partially burned 
(Service 2008c, Table 2). Our inspection also documented the 
bunchgrasses Hesperostipa comata (needle and thread), Poa secunda 
(Sandberg's bluegrass), Pascopyron smithii (western wheatgrass), 
Agropyron cristatum (crested wheatgrass), and Achnatherum hymenoides 
(Indian ricegrass), as well as the shrub Chrysothamnus viscidiflorus 
(green or yellow rabbitbrush) re-sprouting from roots that survived the 
2007 wildfire. These species generally made up approximately 20 percent 
of the total vegetative cover at the burned sites, and it was estimated 
that 75 to 90 percent of the bunchgrasses had survived the wildfire (M. 
Mancuso, Mancuso Botanical Services, in litt. 2008, p. 1).
    In June, 2008, we conducted post-wildfire re-census efforts to 
specifically evaluate the effects of the 2007 wildfire and determine 
the response of Astragalus anserinus to this event. We counted 
individual plants at 12 sites where we had count data from either 2004 
or 2005, including Nevada EO 001, Nevada EO 004, and 10 sites within 
Utah EO 001 (which represents the largest EO). Three of the sites that 
were surveyed were not burned, 5 of the sites were partially burned 
(including Utah EO 001-4-17 which supported 7,486 individuals prior to 
the fire based on 2005 data), and 4 of the sites were completely 
burned. Using pre-2007 information, we estimate that we resurveyed 
habitat containing approximately half of the estimated 31,500 
individuals burned in the 2007 wildfire (Service 2008c, Tables 1 and 
2). Generally, individual plant counts in almost all burned and 
unburned areas were less than those recorded in 2004 and 2005.
    Table 3 provides pre- and post-fire survey data from the 12 sites. 
For the 3 unburned sites, the number of individuals increased by 5.4 
percent at the first site (652 in 2004 to 687 in 2008), decreased by 
76.3 percent at the second site (1,458 in 2004 to 346 in 2008), and 
decreased by 79.0 percent at the third site (3,081 in 2005 to 647 in 
2008) (Service 2008c, Table 2). For the 4 sites that completely burned, 
the number of individuals decreased by 94.9 percent at the first site 
(3,695 in 2005 to 188 in 2008); 98.1 percent at the second site (314 in 
2005 to 6 in 2008); 98.2 percent at the third site (1,115 in 2005 to 20 
in 2008), and 100 percent at the fourth site (224 in 2005 to 0 in 2008) 
(Service 2008c, Table 2).

                                              Table 3. Census results from the 2008 post-wildfire surveys.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                         2004 or 2005
    EO Number and Site Number     Burned or Unburned     2004 or 2005      2004/2005 Number     2008 Number of        Individuals        Percent Area
                                                                            of Individuals        Individuals       Percent Change          Burned
--------------------------------------------------------------------------------------------------------------------------------------------------------
N004-1                            Unburned            2004                652                 687                 +5.4                ..................
--------------------------------------------------------------------------------------------------------------------------------------------------------
U001-7-3                          Part-Burned         2004                1,742               1,134               -34.9               21.3
--------------------------------------------------------------------------------------------------------------------------------------------------------
N001-1                            Part-Burned         2004                541                 173                 -68.0               unknown
--------------------------------------------------------------------------------------------------------------------------------------------------------
U001-6-1                          Unburned            2004                1,458               346                 -76.3               0
--------------------------------------------------------------------------------------------------------------------------------------------------------
U001-4-35                         Unburned            2005                3,081               647                 -79.0               0
--------------------------------------------------------------------------------------------------------------------------------------------------------
U001-4-17                         Part-Burned         2005                7,486               772                 -89.7               94.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
U001-4-33                         Part-Burned         2005                349                 31                  -91.1               unknown
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 46528]]

 
U001-4-30                         Part-Burned         2005                175                 13                  -92.6               81.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
U001-NV-1                         Burned              2005                3,695               188                 -94.9               100
--------------------------------------------------------------------------------------------------------------------------------------------------------
U001-4-12                         Burned              2005                314                 6                   -98.1               100
--------------------------------------------------------------------------------------------------------------------------------------------------------
U001-NV-2                         Burned              2005                1,115               20                  -98.2               100
--------------------------------------------------------------------------------------------------------------------------------------------------------
U001-4-34                         Burned              2005                224                 0                   -100.0              100
--------------------------------------------------------------------------------------------------------------------------------------------------------

    During our field surveys at the 5 sites that were partially burned, 
we observed a 34.9 percent to 92.6 percent decrease between the number 
of Astragalus anserinus individuals counted in 2004 or 2005 and the 
number counted in 2008. The sites that had the most burned area 
generally reflected larger decreases in the number of individual plants 
(Table 3) (Service 2008c, Table 2). Extant A. anserinus individuals 
were also more frequently associated with unburned areas in the 
partially burned sites. For example, approximately 94.6 percent of the 
occupied area within site U001-4-17 was burned during the 2007 wildfire 
(this site represented the site with the most individuals counted prior 
to the 2007 wildfire (7,486)). We observed that 562 of the 772 
individuals counted in U001-4-17 in 2008 (68.1 percent) occurred in the 
5.4 percent of the site that did not burn. Prior to the 2007 wildfire, 
A. anserinus densities were generally higher within the more sparsely 
vegetated areas of occupied sites. It is likely that the number of 
individuals detected within the burned and unburned areas was 
influenced by their pre-wildfire distribution, particularly since 
sparsely vegetated areas were less likely to burn. Because the density 
of individuals at any particular site was not measured at a fine enough 
resolution in the 2004, 2005, or 2007 surveys, it is difficult to 
conclusively compare pre-2007 wildfire densities to post wildfire 
densities.
    We also compared the acreage occupied by Astragalus anserinus 
between that recorded during the 2004 and 2005 census efforts and what 
we observed in June 2008. The occupied acreage decreased at each of the 
12 sites, which included both burned and unburned areas, with a range 
of 37.9 to 100 percent (Service 2008c, Table 2). The occupied acreage 
at the 3 sites that did not burn decreased 62.1 percent, 60.5 percent, 
and 77.4 percent (average = 66.6 percent); the reason for the decrease 
is unknown. The occupied acreage at the 5 partially burned sites 
decreased 37.9 percent, 59.9 percent, 97.3 percent, 86.8 percent, and 
99.4 percent (average = 73.3 percent). The occupied acreage at the 4 
sites that completely burned decreased 90.2 percent, 77.0 percent, 96.0 
percent, and 100 percent (average = 90.8 percent) (Service 2008c, Table 
2). Since explicit data collection protocols were not established to 
differentiate between map points at which an individual was recorded 
and map polygons which indicate an area within which one or more 
individuals were recorded, we considered plants to be within the same 
polygon if they were within 33 to 66 ft (10 to 20 m) of one another. 
For this reason, determining fire effects by comparing the burned, 
unburned, and partially burned acreage is not as accurate as comparing 
the numbers of individuals that were actually counted.
    Despite the significant declines in the number of individuals and 
occupied acreage detected in the 2008 surveys, some Astragalus 
anserinus individuals did survive the effects of the fire. Plants can 
survive wildfires in several ways. Adult plants can survive, plants may 
re-sprout from the base, or plants can re-establish from seed (Brown 
and Smith 2000, p. 33). Field surveys conducted in November 2007 (after 
the 2007 wildfire), documented that most of the above-ground vegetation 
had been removed at several A. anserinus sites. During the subsequent 
2008 field surveys, we observed that some adult plants that survived 
inside burned areas were attached to large woody roots that likely 
survived the wildfire. This suggests that the A. anserinus individuals 
that survived the 2007 wildfire likely re-sprouted after the wildfire. 
If A. anserinus is able to remain dormant during a growing season, the 
low plant numbers we observed in 2008 in unburned sites may indicate 
that some plants were dormant at that time, although we do not have any 
information regarding this capability.
    We also compared the number of Astragalus anserinus seedlings 
counted in 2008 between burned areas and areas that did not burn. We 
observed that seedlings made up 11.4 percent of A. anserinus plants (76 
of 665) in burned areas, 11.5 percent (23 of 200) in partially burned 
areas, and 2.1 percent (68 of 3,222) in unburned areas (Service 2008a, 
Table 1). Seedlings can become re-established from surviving plants, 
seed dispersal from off-site plants, wildfire stimulated seed banks, or 
plants that re-sprout after a wildfire (USFS 2000, p. 33). The 
increased number of seedlings within burned and partially burned areas 
may demonstrate that seed germination was stimulated by the 2007 
wildfire. However, even if this is true, this response did not offset 
the observed individual plant losses resulting from the 2007 wildfire. 
We are unaware of any available information on A. anserinus seed bank 
longevity, and do not fully understand the effect wildfire may have on 
this species. Seed bank studies for other Astragalus species indicate 
that the group generally possesses hard impermeable seed coats with a 
strong physical germination barrier. As a result, the seeds are 
generally long-lived in the soil and only a small percentage of seeds 
germinate each year (summarized in Morris et al. 2002, p. 30). However, 
we do not know if the seed germination strategy for other Astragalus 
species is comparable to that employed by A. anserinus.
    We observed an average 50 percent decline in the number of 
Astragalus anserinus plants counted at the 3 sites that were not burned 
in the 2007 wildfire, compared to pre-fire site data for those areas. 
For sites that were completely burned by the 2007 wildfire, average 
plant numbers declined 97.8 percent from the number of individuals 
counted in 2004 or 2005. In some plant species, seed dormancy is broken 
by wildfire (e.g., Pinus contorta, lodgepole pine), and after a 
wildfire numerous seedlings sprout because this seed dormancy has been 
broken. However, we did not see a significant number of new seedlings 
within burned areas.

[[Page 46529]]

Because of the low numbers of observed individuals and the lack of a 
source for a large flush of seedlings, it is likely that A. anserinus 
recovery will depend on the successful re-colonization of burned areas. 
Because of the generally low number of seedlings counted, where data 
are available, we suspect that this re-colonization may take several 
years and be dependent upon suitable environmental conditions.
    We believe that wildfire frequency will increase within Astragalus 
anserinus habitat. Wildfire return intervals in the sagebrush-steppe 
ecosystem, which includes the Goose Creek drainage, have been 
significantly reduced from between 60 and 110 years to often less than 
5 years. The fact that the 2007 wildfire was the second wildfire 
recorded within a 7-year period in the Goose Creek drainage, with no 
previously recorded wildfires in this area, appears to present 
supporting evidence for increased fire frequency. Wildfire kills 
Astragalus anserinus, and seedling germination does not appear to be 
stimulated by wildfire. Accordingly, increased fire frequency will 
result in fewer A. anserinus individuals, and less seed availability 
for recruitment. The ongoing and cumulative effects of wildfire on A. 
anserinus include a substantial reduction in the amount of available 
habitat, and range-wide population-level effects caused by the loss of 
approximately 98 percent of the individual plants in the burned areas 
(which were roughly 53 percent of the pre-2007 wildfire total known 
individuals). Future wildfires in the area will likely result in 
similar detrimental effects on the remaining population.
    It is likely that Astragalus anserinus recovery will depend on the 
successful re-colonization of burned areas, which will probably occur 
slowly over time. However, because wildfire frequency has increased in 
this area, recovery may be constrained by additional wildfires in the 
relatively near future. Therefore, we find the magnitude of this threat 
to be high.

Wildfire Management

    Wildfire management can include prescribed burning, and activities 
associated with fighting wildfires such as the construction of fire 
lines and staging areas, retardant application, and post-wildfire 
restoration efforts such as disking and seeding. In 2008, disking and 
seeding associated with soil stabilization activities occurred over 
portions of 11 Astragalus anserinus sites in Utah in response to the 
2007 wildfire (Service 2008c, Tables 2-4, Map 4; Service, in litt. 
2008, photos 1-3). It is likely that numerous individual plants were 
lost to site re-seeding efforts and road construction activities. We 
also observed in some cases that A. anserinus root systems had been 
exposed, and believe that it is likely that individual plants were 
turned over and buried during the disking operations. These actions 
likely killed individual plants, thereby compounding the ongoing 
detrimental effects of the wildfire itself on the A. anserinus 
population.
Firefighting Activities
    Firefighting activities such as prescribed burning, road and fire 
line construction and retardant application can destroy habitat and 
kill or injure individual Astragalus anserinus plants. Such activities 
occurred during the response to the wildfire in 2007. Advance A. 
anserinus surveys were not conducted because of the immediate need to 
respond to the 2007 wildfire (M. Gates, Salt Lake City BLM, in litt. 
2008a). During a brief field inspection of the area affected by 
firefighting activities prior to our 2008 post-fire surveys, we 
observed that at least one new road had been constructed along a ridge, 
and that several fire lines had been excavated by hand adjacent to A. 
anserinus habitat. We also observed that a wide fire line had been 
constructed between 2 known EOs. During our 2008 post-wildfire surveys 
over 18 A. anserinus occupied sites, we observed that fire retardant 
had been applied at 1 site over an area approximately 10 ft (3 m) in 
radius (U001-4-35). We also observed that a new access road had been 
constructed through site U001-7-3, and evidence of tire tracks in 
occupied areas at site U001-4-33.
    One study of the effects of fire retardant chemical (Phos-Chek G75-
F) and fire suppressant foam (Silv-Ex) application, alone and in 
combination with fire, on Great Basin shrub steppe vegetation found 
that growth, resprouting, flowering, and incidence of galling insects 
on Chrysothamnus viscidiflorus (yellow rabbitbrush) and Artemisia 
tridenta (Big sagebrush) were not affected by any chemical treatment. 
In general, the study found that species richness declined, especially 
after Phos-Check application, but by the end of the growing season, 
species richness did not differ between treated and control plots 
(Larson et al. 1999, p. 115). We are unaware of the specific retardant 
used in the 2007 fire response, or whether A. anserinus would be 
similarly unaffected. However, based on the limited extent of the area 
that was treated with retardant, we do not anticipate any significant 
long-term impacts to the overall A. anserinus population. In addition, 
since advance A. anserinus surveys were not conducted because of an 
immediate need to respond to the wildfire, we do not know if the other 
activities adversely affected the species. Some fire fighting 
activities could present a future threat to A. anserinus, depending on 
their specific location and scale; however, we are unable to assess the 
magnitude of those potential threats at this time.
Post Wildfire Emergency Stabilization and Restoration
    Post-wildfire restoration activities can also destroy habitat, kill 
or harm individuals, and introduce nonnative species, which may 
outcompete Astragalus anserinus for resources. The following is a 
discussion of restoration activities that occurred after the 2008 
fires.
    2007 Wildfire Emergency Stabilization and Restoration in Nevada: 
Following the 2007 wildfire season, the BLM Elko Nevada Field Office 
(BLM-Nevada) developed a soil stabilization plan for implementation in 
2008 that included reseeding several areas affected by the fire. A 
native grass restoration seeding effort was planned near EO 005, but 
was not conducted (Howard 2007, p 3). Post-fire aerial seeding of 
Artemisia tridentata var. wyomingensis (Wyoming sagebrush), which is 
native to Goose Creek, was undertaken within drainages at or near the 
site instead of the native grass restoration seeding effort (K. Fuell, 
Elko BLM, in litt. 2008, p. 1). This action may be beneficial to 
Astragalus anserinus, however we are unaware of the specific treatment 
locations, whether the efforts were successful, or whether they 
affected A. anserinus in EO 005.
    2007 Wildfire Emergency Stabilization and Restoration in Utah: 
Restoration seeding activities in Utah were conducted in late May and 
early June, 2008, as part of an Emergency Stabilization Plan (ESP) that 
was developed by BLM to treat areas affected by the 2007 wildfire. A 
fencing project and juniper removal chaining efforts (using a chain 
connected between two tractors) were included as elements of this plan. 
Under the ESP, disk seeding with a mix of native and nonnative species 
(see ``Nonnative Invasive Species--seeded'' below) was conducted within 
Astragalus anserinus habitat in an area west of Grouse Creek Road to 
stabilize the soils, prevent erosion, and minimize competition by 
Bromus tectorum (cheatgrass) in the burned area. Areas to be avoided 
were identified in advance with flagging to

[[Page 46530]]

prevent impacts to A. anserinus from planned juniper removal chaining 
operations and seeding efforts (M. Gates, in litt. 2008b, p. 1). 
However, not all A. anserinus sites were avoided.
    The rangeland drills employed in the Utah