astragalus anserinus - endangered species

8/9/2019 Astragalus anserinus - Endangered Species

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46521Federal Register / Vol. 74, No. 174/ Thursday, September 10, 2009/ Proposed Rules

the magnitude of risks in a project, andto help the project sponsor predict andestablish a project budget and schedule.The most important objective of riskassessment and management protocolsis to help the project sponsor predict the

budget and schedule and to ensure thatthe sponsor can complete the projectwithin the budget and schedule

identified in the FTA grant award.Project risks track the project

development process. In general terms,they can be described as follows:

Requirements Risk. The first step inproject development is to identify therequirementsrisks associated withdefinition of basic project needs andtransit system requirements to meetthose needs;

Design Risk. The second step isproject designrisks involving theadequacy of the information available ateach stage of design and engineering,geotechnical conditions in particular,

and the impact of redesign; Market Risks. The third step is to

identify market risksrisks associatedwith both the procurement approachand the market conditions that canaffect the cost of materials and theavailability of bidders for constructionservices, materials, real estate, andmanufactured products like vehicles;and

Construction Risks. The final step isto identify construction risksthoserisks associated with the actualconstruction and start-up of the system.

Once risks are identified, FTA and

project sponsors must determine thebest method for managing those risks.The preferred methods for managingrisk are avoidance, reduction, andmitigation. Because they are really onlyways of providing more up-frontfunding or reducing overall costs but donot reduce risk, less preferred riskmanagement techniques includeincreasing contingency, reducing projectscope, or reducing the level of service.FTA works with each project sponsor todetermine the most feasible strategy foreach project.

Project sponsors document this risk-

informed management process in theproject management plan. Includingthese strategies can help ensure that theproject sponsor has the requisitetechnical capacity and capability todeliver the project on time and within

budget by ensuring that the projectsponsor understands methods foraddressing risks and that it implementsstrategies to avoid future delays.

FTA can tailor these risk assessmentand management tools to take intoaccount the unique circumstances of aproject, such as sponsor organization

and technical capacity and capability,and the project complexity or status.

C. Questions

1. Should FTA assign PMOCs tooversee projects other than MajorCapital Projects? Please provide therationale for your recommendationsincluding how oversight of these

projects should alternatively beprovided if PMOCs are not utilized.

2. At what stage in the developmentprocess should FTA assign PMOCs toNew Starts projects? Explain the basisfor your recommendation.

3. Other than a detailed review of agrantees financial plan, what othermethods might FTA utilize to ensure agrantee has the financial capacity toconstruct and operate a major capitalproject?

4. Please comment on FTAs RiskManagement approach. If you do notagree with FTAs approach, please

recommend an alternative and providea basis for your recommendation.Following the close of the comment

period on this ANRPM, FTA willsummarize and respond to thecomments and issue a Notice ofProposed Rulemaking that positsexplicit text for a rewrite of theregulation at 49 CFR Part 633. Weexpect to publish such a Notice ofProposed Rulemaking in 2009.

Issued this 4th day of September, 2009.

Peter M. Rogoff,

Administrator, Federal TransitAdministration.

[FR Doc. E921849 Filed 9909; 8:45 am]BILLING CODE P

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWSR1ES20090006]

[MO 922105 0082B2]

Endangered and Threatened Wildlifeand Plants; 12-Month Finding on aPetition to List Astragalus anserinus

(Goose Creek milkvetch) asThreatened or Endangered

AGENCY: Fish and Wildlife Service,Interior.

ACTION: Notice of a 12month petitionfinding.

SUMMARY: We, the U.S. Fish andWildlife Service (Service), announce our12month finding on a petition to listAstragalus anserinus (Goose Creekmilkvetch) as a threatened orendangered species under the

Endangered Species Act of 1973, asamended (Act). After a thorough reviewof all available scientific andcommercial information, we find thatlisting A. anserinus under the Act iswarranted. However, listing is currentlyprecluded by higher priority actions toamend the Lists of Endangered andThreatened Wildlife and Plants. We

have assigned a listing priority number(LPN) of 5 to this species, because thethreats affecting it have a highmagnitude, but are non-imminent. Uponpublication of this 12month petitionfinding, A. anserinus will be added toour candidate species list. We willdevelop a proposed rule to list A.anserinus as our priorities allow. Anydeterminations on critical habitat will

be made during development of theproposed rule.DATES: The finding announced in thisdocument was made on September 10,2009.

ADDRESSES: This finding is available onthe Internet at http://www.regulations.govat Docket NumberFWSR1ES20090006. Supportingdocumentation we used to prepare thisfinding is available for publicinspection, by appointment duringnormal business hours at the U.S. Fishand Wildlife Service, Utah Field Office,2369 West Orton Circle Suite 50, WestValley City, Utah 84119. Please submitany new information, materials,comments, or questions concerning thisfinding to the above address or viaelectronic mail (e-mail) at http://

[email protected] FURTHER INFORMATION CONTACT:Larry Crist, Field Supervisor, U.S. Fishand Wildlife Service, Utah Field Office(see ADDRESSES)); by telephone at 8019753330; or by facsimile at 8019753331. If you use a telecommunicationsdevice for the deaf (TDD), call theFederal Information Relay Service(FIRS) at 8008778339.SUPPLEMENTARY INFORMATION:

Background

Section 4(b)(3)(B) of the Act (16U.S.C. 1531 et seq.) requires that, for

any petition containing substantialscientific and commercial informationthat listing may be warranted, we makea finding within 12 months of the dateof receipt of the petition on whether thepetitioned action is: (a) Not warranted,(b) warranted, or (c) warranted, butimmediate proposal of a regulationimplementing the petitioned action isprecluded by other pending proposals todetermine whether species arethreatened or endangered, andexpeditious progress is being made toadd or remove qualified species from

VerDate Nov2008 13:54 Sep 09, 2009 Jkt 217001 PO 00000 Frm 00010 Fmt 4702 Sfmt 4702 E:\FR\FM\10SEP1.SGM 10SEP1
http://www.regulations.gov/http://www.regulations.gov/http://www.regulations.gov/http://www.regulations.gov/http://www.regulations.gov/http://www.regulations.gov/http://www.regulations.gov/http://[email protected]/http://[email protected]/http://[email protected]/http://[email protected]/http://[email protected]/http://www.regulations.gov/


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46522 Federal Register / Vol. 74, No. 174/ Thursday, September 10, 2009/ Proposed Rules

the Lists of Endangered and ThreatenedWildlife and Plants. Section 4(b)(3)(C) ofthe Act requires that we treat a petitionfor which the requested action is foundto be warranted but precluded as thoughresubmitted on the date of such finding;that is, requiring a subsequent finding to

be made within 12 months. We mustpublish these 12month findings in the

Federal Register.

Previous Federal Actions

On February 3, 2004, we received apetition dated January 30, 2004, fromRed Willow Research, Inc., and 25 otherconcerned parties (the Prairie FalconAudubon Society Chapter Board,Western Watersheds Project, UtahEnvironmental Congress, SawtoothGroup of the Sierra Club, and 21 privatecitizens) requesting that we listAstragalus anserinus as threatened orendangered, emergency list the species,and designate critical habitat

concurrently with the listing (RedWillow Research Inc, in litt. 2004). Weacknowledged the receipt of the petitionin a letter to the petitioners in a letterdated February 19, 2004. In that letter,we advised the petitioners that ourinitial review of the petition determinedthat emergency listing was notwarranted, and that if conditions changewe would reevaluate the need foremergency listing. We informed thepetitioner that in light of resourceconstraints, we anticipated making ourinitial finding in Fiscal Year 2005 as towhether the petition containedsubstantial information indicating thatthe action may be warranted.

On August 16, 2007, we published anotice of 90day finding (72 FR 46023)that the petition presented substantialscientific or commercial informationindicating that listing A. anserinus may

be warranted, and that we wereinitiating a status review of the species.For more information, refer to the 90day finding that was published in theFederal Register on August 16, 2007 (72FR 46023). We received informationfrom the Bureau of Land Management,Idaho Department of Fish and Game,Red Willow Research Inc. (the

petitioner), and the Cassia County WeedControl office in response to the 90dayfinding. All information received has

been fully considered in this finding.In accordance with the Presidents

memorandum of April 29, 1994,Government-to-Government Relationswith Native American Tribal

Governments (59 FR 22951), ExecutiveOrder 13175, and the Department of theInteriors manual at 512 DM 2, wereadily acknowledge our responsibilityto communicate meaningfully withrecognized Federal Tribes on agovernment-to-government basis. Inaccordance with Secretarial Order 3206of June 5, 1997 (American Indian Tribal

Rights, Federal-Tribal TrustResponsibilities, and the EndangeredSpecies Act), we readily acknowledgeour responsibilities to work directlywith the Tribes in developing programsfor healthy ecosystems, to acknowledgethat Tribal lands are not subject to thesame controls as Federal public lands,to remain sensitive to Indian culture,and to make information available toTribes. In fulfilling our trustresponsibilities for government-to-government consultation with Tribes,we met with the Shoshone Paiute Tribesregarding the process taken to conduct

a 12month status review ofAstragalusanserinus. As an outcome of ourgovernment-to-governmentconsultation, we recognize the strongcultural significance ofA. anserinus tothe Shoshone Paiute Tribes andacknowledge that in this 12monthfinding. This notice constitutes the 12month finding on the January 30, 2004,petition to list A. anserinus asthreatened or endangered.

Species Information

Astragalus anserinus was firstcollected in 1982 by Duane Atwoodfrom a location in Box Elder County,Utah, and subsequently described in1984 (Atwood et al. 1984, p. 263). Thespecies is known only from tuffaceous(ashy) soils found near Goose Creek onthe Idaho, Nevada, and Utah border, anarea approximately 20 miles (mi)(32.5kilometers (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-purpleflowers, and brownish-red curved seedpods (Mancuso and Moseley 1991, p. 4).This species is distinguished from A.calycosus (Torreys milkvetch), A.

purshii(woollypod milkvetch), and A.newberryi(Newberrys milkvetch), thethree other mat-forming Astragalusspecies found in the Goose Creekdrainage, primarily by its smallerleaflets and flowers, as well as the colorand shape of the seed pods (Baird andTuhy 1991, p. 1; Mancuso and Moseley

1991, pp. 45). In our August 16, 2007,90day finding (72 FR 46023), we usedthe common name for the species,Goose Creek milk-vetch. Here we useAstragalus anserinus for accuracy,and Goose Creek milkvetch (un-hyphenated) to make the taxonomymore consistent with todays botanicalnomenclature.

Biology, Distribution, and Abundance

Astragalus anserinus typically flowersfrom late May to early June. The speciesis assumed to be insect-pollinated, butthe specific pollinators are unknown(Baird and Tuhy 1991, p. 3). Fruit set

begins in early June with fruitsremaining on the plants for severalmonths. Mechanisms of seed dispersalare also unknown, but may includewind dispersion of seed pods and insector bird agents (Baird and Tuhy 1991, p.3). Because A. anserinus often grows onslopes and because the seed pods are

found close to the ground below thevegetative portions of the plant, water orgravity dispersal may also be a dispersalmechanism. In 2004 and 2005, clustersof seedlings were occasionally observedon abandoned ant hills, which couldsuggest some ant dispersal. Littlescientific research specific to A.anserinus has been conducted beyond a

basic species description and varioussurvey efforts.

Limited information is availableregarding Astragalus anserinuslongevity. In September 2004, the U.S.Bureau of Land Management (BLM)Field Office in Burley, Idaho (BLM-Idaho), permanently marked 10seedlings in a wash at the base of atuffaceous outcrop (soils comprised ofvolcanic 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 thirdsite (Site 3) (A. Feldhausen, BurleyBLM, in litt. 2007a, pp. 89). The resultsof this effort are summarized in Table 1

below. In a separate monitoring effort,BLM-Idaho conducted annual countingofA. anserinus individuals at two sites(Big Site 1 and Big Site 7) from 2004 to2007. These results are depicted in

Table 2 below. In combination, thesetwo studies demonstrate largefluctuations in the number ofindividuals between years, with Table 2reflecting almost a doubling or halvingin magnitude between the numbers ofindividuals observed in successiveyears.



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TABLE 1. SHORT-TERM TRACKING OF Astragalus anserinusINDIVIDUALS (20042006) (A. FELDHAUSEN, IN LITT. 2007A,PP. 89).

YearSite 1 Site 2 Site 3

Seedlings Seedlings Adults Seedlings Adults

2004 10 seedlings 8 seedlings 7 adults 12 seedlings 10 adults

2005 4 dead, 2 small

seedlings (15leaves each), 4small adult plantswith pods

6 dead, 1 small

seedling (12leaves), 1 youngadult

1 dead, 6 alive 1 stake missing, 5

dead, 6 smalladults (3 withpods)

1 dead, 9 with des-

iccated leaves andnumerous pods

2006 All 6 remaining plantsswept away bywater in a wash

Of the 7 remainingadult plants, 2dead and 5 alive

Of the 6 remainingstakes: 1 stakemissing, 4 dead, 1adult

7 dead, 3 stakesmissing

TABLE 2. MONITORING OF Astragalusanserinus AT TWO SITES IN IDAHO(A. FELDHAUSEN, IN LITT. 2007A,PP. 89; IDAHO CONSERVATIONDATA CENTER (IDCDC) 2007A,

ELEMENT OCCURRENCE (EO) 003).

Year Big Site 1 Big Site 7

2004 123 total (2dead, 73seedlings,48 adults)

138 total (42seedlings,96 adults)

2005 136 total (8dead, 13seedlings,115adults)

67 total (3dead, 6seedlings,58 adults)

2006 88 total 135 total

2007 73 total 69 total

These wide-ranging fluctuations inthe number ofAstragalus anserinusindividuals observed suggests that thespecies is either short-lived or that adultplants may remain dormant duringsome growing seasons. If the species isshort-lived, correspondingaugmentation of seedlings to replacelost individuals would be expected;however, this has not been observed.During spring census efforts, seedlings(defined as young developing plantshaving 3 or fewer leaves) made up 1,433of the 30,281 individuals that werecounted in 2005 (4.7 percent), and 167of the 4,087 individuals counted in 2008(4.1 percent) (Service 2008a, p. 1). Thedefinition of seedlings used forpurposes of Table 2 is different than thatused in the 2004, 2005, and 2008 censusefforts; with seedlings in Table 2 beingdefined by young developing plantswith cotyledons (the first leaves toemerge from the ground) present.Seedlings made up 59.3 percent of thetotal individuals at Big Site 1 in 2004,and 9.6 percent of the total individuals

in 2005. Seedlings also made up 30.4percent of the total individuals at BigSite 2 in 2004, and 8.9 percent of thetotal individuals in 2005 (J. Tharp,Burley BLM, in litt., 2008a, p. 1).Although we have no direct informationon A. anserinus seedling germination, itwould likely be more or less abundantdepending on the time of year sampled.We expect spring would be the mostlikely time to observe A. anserinusseedlings, like many other plants, andthe seedlings could be more numerousin years when climatic conditions aremore amenable to their germination andestablishment. One such climatic factorcould be annual precipitation; theamount and timing of this precipitationover the course of a year could influenceseed germination and seedlingrecruitment.

During field surveys, several smallerAstragalus anserinus plants werepartially excavated and observed to beattached to large woody roots. Parts ofsome individual plants frequentlyappeared to be dead, with only a smallgreen portion remaining. This suggeststhat vegetative growth may vary duringsuccessive years, and that plant sizemay not necessarily correspond to theage of the individual. This also suggeststhat some A. anserinus individuals mayremain dormant for an entire growingseason. In at least one other species ofAstragalus (A. ampullarioides), adult

plants can exhibit dormancy (aninactive state) during a growing season,and the perennial rootstock allows theplant to survive dry years (Van Burenand Harper 2003b in Service 2006a, p.8). However, monitoring studies todetermine whether A. anserinus alsohas this ability have not beenconducted.

Table 2 also demonstrates thatfluctuations in the number ofAstragalusanserinus individuals can vary acrosssites during a given year. For example,the number of individuals counted at

Big Site 1 decreased from 136 to 88between 2005 and 2006, whereas thenumber of individuals counted at BigSite 7 increased from 67 to 135 duringthe same time period. However,

between 2006 and 2007, the number ofindividuals counted at Big Site 1decreased from 88 to 73 and the numberof individuals counted at Big Site 7decreased 135 to 69. Since these sitesare approximately 0.5 mi (0.8 km) aparton similar aspects, this suggests thatlocal weather patterns may not be apredominant factor influencing plantabundance and annual survival.

Although we acknowledge there aresome uncertainties with regard tolongevity, plant dormancy, and theeffect of climatic factors on A.anserinus, the observed populationtrend has been a decrease in the number

of observed individuals.Astragalus anserinus is endemic tothe Goose Creek drainage in CassiaCounty, Idaho; Elko County, Nevada;and Box Elder County, Utah. The GooseCreek drainage occurs within the GreatBasin ecosystem; this drainage receivesan annual rainfall average of less than12 inches (30 centimeters). ElementOccurrences (EOs) are areas where aspecies was or is recorded to be present.The known EOs ofA. anserinus occurat elevations ranging between 4,900 to5,885 feet (ft) (1,494 to 1,790 meters (m))(Idaho Conservation Data Center

(IDCDC) 2007b, p. 2; Smith 2007, Table1). Most A. anserinus EOs are within anapproximate 20-mi (32-km) long by 4-mi(6.4-km) wide area, oriented in asouthwest to northeasterly directionalong Goose Creek. However one A.anserinus EO has been documentedoutside of the Goose Creek watershedapproximately 2 mi (3.2 km) south ofany other EOs. The geographic range ofthe species has not been extended fromthat presented in the 90day finding (72FR 46023; August 16, 2007). Based onnew information from surveys



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conducted in Nevada in 2006, duringwhich several new EOs werediscovered, gaps in the range have beenfilled with the 6 new EOs extendingtoward the 1 EO outside of the GooseCreek drainage.

Astragalus anserinus occurs in avariety of habitats, but is typicallyassociated with dry tuffaceous soils

from the Salt Lake Formation that havea silty to sandy texture (Mancuso andMoseley 1991, p. 12). In Utah, soil serieswhere A. anserinus has been locatedinclude Bluehill fine sandy loam,Codquin gravelly sandy loam,Cottonthomas fine sandy loam, andTomsherry fine sandy loam (Hardy2005, p. 4). The species has beenobserved growing on steep or flat sites,with soil textures ranging from silty tosandy to somewhat gravelly. Thesehabitats can vary from stable areas withlittle erosion to washes or steep slopeswhere erosion is common. It appears

that the species tolerates, and mayproliferate with, some level ofdisturbance, based on its occurrence onsteep slopes where downhill movementof soil is common, within erodedwashes, and along road margins andedges of cattle trails. However,individuals have not been observedwhere vehicle or livestock travel isfrequent or where water flows throughwashes on a regular basis.

Astragalus anserinus is generally notfound on north-facing slopes, but isfound on most other slope aspectswithin sparsely vegetated areas insagebrush and juniper habitats. The

estimated total plant cover (of allspecies) at sites where A. anserinusoccurs is between 10 and 35 percent(Hardy 2005, p. 4; Smith 2007, p. 2).The dominant native species within thegeneral surrounding plant communityinclude Artemisia tridentata ssp.wyomingensis (Wyoming big sagebrush),

Juniperus osteosperma (Utah juniper),Chrysothamnus viscidiflorus (green oryellow rabbitbrush), Poa secunda(Sandbergs bluegrass), andHesperostipa comata (needle and threadgrass). A. anserinus is frequentlyassociated with a suite of native species

that reside on the tuffaceous sand (Bairdand Tuhy 1991, pp. 23) including:Achnatherum hymenoides (Indianricegrass), Chaenactis douglasii(Douglas dustymaiden), Cryptanthahumilis (roundspike cryptantha),Eriogonum microthecum (slender

buckwheat), Eriogonum ovalifolium(cushion buckwheat), Ipomopsiscongesta (= Gilia congesta; ballheadgilia), Mentzelia albicaulis (whitestem

blazingstar), and Phacelia hastata(silverleaf phacelia). Several nonnativespecies also co-occur with A. anserinus

(see Nonnative Introduced Speciesunder Summary of Factors Affecting theSpecies Rangewide: Factor A, below).Another Goose Creek drainage endemic,Penstemon idahoensis (Idahopenstemon), is found near A. anserinus,

but these species are seldom foundimmediately adjacent to one another.Other sensitive species in the area

include Arabis falcatoria (= Boecherafalcatoria; falcate rockcress), andPotentilla cottamii(Cottams cinquefoil)(Franklin 2005, pp. 910, 159160).

The Heritage/Conservation DataCenter programs in Idaho, Nevada, andUtah rank Astragalus anserinus as a G2species, indicating the species isimperiled throughout its range becauseof rarity or other factors that make itvulnerable to extinction, and S1(critically imperiled) in the three states(IDCDC 2007b, p. 2). Heritage/Conservation Data rankings do not offerany sort of protection, but are often used

to guide other agencies and entities indesignating sensitive species. The BLMhas assigned different statusdesignations to the species in the threestates where it occurs. In Idaho, A.anserinus is designated as a type 2species, which reflects a rangewide orglobally imperiled species with a highendangerment status. In Utah, thespecies is designated as a sensitive plantspecies (Fortner 2003 in Franklin 2005,p. 17), and in Nevada the species isdesignated as a special status species(Morefield 2001, p. 1). BLM policyprovides that species which aredesignated as a sensitive species shall

be protected as candidate species forlisting under the Act (BLM 2001, p.06C1).

Astragalus anserinus is currentlyknown from 19 EO records (5 in Idaho,10 in Nevada, and 4 in Utah) (IDCDC2007b, p.4; Smith 2007, p. 1; UtahConservation Data Center (UCDC) in litt.2007, map; Service 2008b, 17 pp.). Thenumber of currently known EOs (19)differs from the 24 EOs identified in the90day finding published on August 16,2007 (72 FR 46023). Recently publishedNatureServe guidelines for designatingEOs in Idaho and Utah (IDCDC 2007b,

p. 1; R. Fitts, Utah Conservation DataCenter, in litt. 2008, p. 1) state that sites(occupied points, lines, or polygons)that occur within 0.6 mi (1 km) of eachother are within the same EO.Accordingly, several occupied sites thatwere designated as individual EOs inour August 16, 2007, 90day findingwere combined. In addition, six newEOs were discovered in Nevada as aresult of survey efforts in 2006. Wedeveloped a naming convention to helpus manage and compare EO data forrecently consolidated sites before and

after implementation of the NatureServeguidelines. For example, the designationU001417 identifies Utah EO 001,which was previously identified as UtahEO 004. The suffix 17 reflects a sitenumber that has been assignedaccording to the sequence the site wascounted in 2004 or 2005. We use ournaming convention as described, as well

as EO number in various placesthroughout this finding, depending onthe context of the particular site beingreferenced.

The majority ofAstragalus anserinussites in Idaho, Utah, and Nevada occuron Federal lands managed by the BLM(Service 2008, 17 pp.). In 2004 and2005, we conducted a multiagencycensus and survey effort for A.anserinus with the BLM, USFS, andnatural resource agencies from theStates of Idaho, Nevada, and Utah. Ourobjective was to count (census) knownsites, survey additional areas, and

document any new populations. In2004, we examined 33 sites in 5 EOs inIdaho (3,467 individuals were counted);6 sites in 3 EOs in Nevada (2,252individuals were counted); and 11 sitesin 2 EOs in Utah (7,558 individualswere counted) (Service 2008, 17 pp.). In2005, we examined 5 sites at 1 EO inNevada (3,074 individuals werecounted), and 64 sites in 1 EO in Utah(27,207 individuals were counted)(Service 2008, 17 pp). During the 2004and 2005 census efforts, 40,858individual plants of the estimated60,000 individual plants range-wide (68percent) were counted at 119 sites in 12

EOs.Estimating the total Astragalus

anserinus population size iscomplicated because of the variability inthe species annual abundance, and thedifferent census and survey methodsthat have been employed. For example,plant abundance at one site in Idahoover a 4year period variedsignificantly: 138 plants were countedin 2004; 67 plants in 2005; 135 plantsin 2006; and 69 plants in 2007 (Service2008, 17 pp.). Census efforts in 2008 at3 sites that were not affected by asignificant wildfire in 2007

demonstrated a general decrease fromplant counts when compared to the2004 or 2005 data; 1 site increased by5.4 percent (652 to 687), 1 site decreased

by 76.3 percent (1,458 to 346), and 1 sitedecreased by 79.0 percent (3,081 to 647)(Service 2008c, Table 2). Using the bestavailable data for each A. anserinus site,we estimate that there wereapproximately 60,000 individualsdistributed across the three states priorto the 2007 wildfires (Service 2008, 17pp.). However, we recognize theinherent variability associated with



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estimating population size, because oflarge fluctuations observed betweensuccessive monitoring years and thediffering census and survey methodsthat have been employed. Generally, the2004 and 2005 census counts yieldedhigher numbers than had beenestimated by previous surveys (Service2008, pp. 16), however, monitoring

efforts have not occurred regularlyenough or over a long enough period toallow us to statistically analyzepopulation trends.

Based on pre-2007 (pre-wildfire)individual plant count data,approximately 10 percent of all knownAstragalus anserinus individuals occurin Idaho (5,500 plants), 25 percent occurin Nevada (15,500 plants), and 65percent occur in Utah (39,000 plants)(Service 2008c, Table 1). State-specificinformation on the population status ofA. anserinus is described below.

Idaho

Prior to 2004, seven EOs (which arenow combined into four EOs under theNatureServe guidelines) were monitored

by the IDCDC, who reported the numberofAstragalus anserinus individuals atmost 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)), butsystematic or comprehensive surveyswere not conducted in Idaho until 1991(Mancuso and Moseley 1991, p. iii). In1991, the A. anserinus population inIdaho was estimated at over 914individuals (Mancuso and Moseley

1991, pp. 2, 1314).During the 2004 census effort, the fourknown Astragalus anserinus EOs inIdaho were revisited and three new siteswere located (two sites were within anexisting EO and one new site wasconsidered to be a new EO). In total,5,052 A. anserinus individuals werecounted, with 2,460 of these individualsobserved within the original 4 IdahoEOs (Service 2006b, Table 1). Based onpre-2007 EO revisions, census data from2004 indicated: (a) stable plant numbersat four EOs; (b) an increase in plantnumbers at one EO (compared to pre-

2004 survey numbers); and (c) anunknown change at two EOs(participants were unable to conduct acomplete census because part of the EOsare on private property) (Service 2006b,Table 1). However, because of thedifferent survey methodologiesemployed before 2004, it is difficult toconclusively compare survey andcensus results or estimate long-termpopulation trends for A. anserinus inIdaho (Service 2006b, Table 1).

In 2007, the IDCDC standardized itsmethodology for designating Astragalus

anserinus EOs to conform to the abovereferenced NatureServe guidelines.Under the new methodology, the fourexisting EOs and the three new sitesfound in 2004 were combined into fiveEOs (EOs 1, 6 and 7 were deleted andadded to EO 3; EO 9 was added as a newEO (IDCDC 2007b, p. 4)). The IDCDCmethodology also ranks the health of the

EOs based on a weighted formula madeup of three elements: EO size (33percent); EO condition (based on theabundance of native plants, introducedplants, and anthropogenic disturbance)(33 percent); and EO landscape context(based on the degree of habitatfragmentation) (33 percent). Rankingsare categorized from A through D, withA ranked EOs generally representinghigher numbers of individuals andhigher quality habitat, and D rankedEOs generally representing lowernumbers of individuals and lowerquality (or degraded) habitat. Under this

ranking system, the IDCDC assigned anA ranking to one EO, B rankings totwo EOs, and C rankings to two EOs(IDCDC 2007b, p. 4).

Monitoring efforts and results inIdaho that have been used to inform thisstatus assessment for Astragalusanserinus include: (a) the collection ofplant community data andestablishment of photo-points in 2000and 2001 at 3 sites (Mancuso 2001a, pp.89; Mancuso 2001b, p. 2); (b) censusefforts at all Idaho EOs on public landin 2004 (Service 2008b, 17 pp.); (c)conducting annual census efforts at 2sites in Idaho since 2004, as

summarized in Table 2 above (A.Feldhausen, in litt. 2007a, pp. 89;IDCDC 2007a, EO 003); (d) thepermanent marking and monitoring ofA. anserinus individuals at 3 sites from2004 to 2006 as summarized in Table 1(A. Feldhausen, in litt. 2007a, pp. 89);and (e), establishing A. anserinus Penstemon idahoensis Euphorbiaesula (leafy spurge) control study plotsat 11 sites in 2007 by BLM-Idaho (A.Feldhausen in. litt. 2007a, p. 3).

Nevada

Astragalus anserinus surveys in

Nevada were first conducted in 1991and 1992, resulting in thedocumentation of 4 EOs, with anestimated plant abundance of 827individuals (Morefield 2001, p. 1).Subsequent census efforts in 2004 and2005 failed to locate any new sites until2006, when 6 new EOs withapproximately 11,000 individuals werediscovered. The 6 new EOs represent18.3 percent of the estimated range-widepopulation total of 60,000 individuals(Service 2008b, 17 pp.). There arepresently ten known EOs in Nevada, as

documented by the Nevada NaturalHeritage Program (NNHP) (Smith 2007,p. 1). Site visits to 4 EOs wereconducted during the 2004 and 2005census efforts, and 4,930 A. anserinusindividuals were counted. However,

because of the different surveymethodologies employed prior to 2004,it is difficult to conclusively compare

survey and census results or estimatelong-term population trends for thespecies in Nevada (Service 2006b, Table1). In 2008, we counted individuals attwo sites during our post-2007 wildfireassessment study, including EO 001(which partially burned), and site 1 ofEO 004 (which did not burn). Weobserved that the number of individualsin EO 001 decreased by 68 percent,while the number of individuals in EO004 increased by 5.4 percent (Service2008c, Table 2) (see the discussionunder Wildfirebelow for further detailson the 2008 study).

Monitoring efforts and results inNevada that have been used to informthis status assessment include censusefforts conducted in 2004 and 2005 atfour EOs (Service 2008b, 17 pp.), andpost-wildfire census efforts in 2008 attwo EOs (one that partially burned, andone that did not burn) (Service 2008c,Table 2, Map 2).

Utah

There were 9 known Astragalusanserinus EOs in Utah with anestimated 7,617 individuals, based onthe results of initial surveys conductedin 1990 and 1991 (Baird and Tuhy 1991,

p. 2; Morefield 2001, p. 1). Eight of theseEOs were documented by the UCDC,and one EO was documented in theNevada Natural Heritage Programdatabase, although it was not reflectedin the UCDC database (Mancuso andMoseley 1991, p.2). There wereadditional Utah surveys in 1993 (Hardy2005, p. 4), however we do not knowwhether they were resurveys of knownsites and do not believe the results areincluded in the UCDC database. TheBLM Salt Lake City, Utah field office(BLM-Utah) staff indicates that they areaware of data from at least one

additional site that has not beensubmitted to the UCDC (Hardy 2005, p.4). In addition, surveys were conductedin Utah by BLM in 2000, 2001, and 2004to evaluate the environmental effects ofa waterline and livestock water tankconstruction project to the species(Hardy 2005, p. 5); no sensitive plantswere discovered along the proposedwater line.

Site visits conducted to what wasthen 6 known EOs, and 1 new siteduring 2004 and 2005 census effortsrecorded a total of 33,476 Astragalus



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anserinus individuals, although onlypartial plant counts were conducted at3 of the 6 known EOs. Two otherdocumented EOs that had the greatestnumbers of individuals werent countedduring the 2004 and 2005 census efforts

because of limitations on access andtime constraints (Service 2006b, Table1). The 2004 and 2005 census data

indicated higher A. anserinus countnumbers than the previous estimates atfive of the known EOs. However,

because of the different surveymethodologies that were used before2004, we are unable to conclusivelycompare survey and census results orestimate long-term population trends forthe species in Utah (Service 2006b,Table 1).

In early 2007, the UCDC reconfiguredAstragalus anserinus EOs in Utah toconform to the general EO standardsguidebook, IDCDC methodology, andNatureServe guidelines, resulting in the

combining of the nine previouslydocumented EOs into four EOs (R. Fitts,in litt. 2008). Based on 2005 censusestimates, the largest Utah EO (EO 001)supported over 37,000 plants, makingup over 60 percent the knownindividuals range-wide (Service 2008b,17 pp.).

In 2008, re-census efforts wereconducted as part of a post-wildfireassessment at ten sites in Utah wherewe had information on the number ofindividuals 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 plantsdecreased by 76.3 percent and 79percent. At the 4 sites that partially

burned, the individual numbers ofplants decreased by 34.9 percent, 89.7percent, 91.1 percent, and 92.6 percent.The individual plant counts at the 4sites that completely burned decreased

by 94.9 percent, 98.1 percent, 98.2percent, and 100 percent (Service 2008c,Table 2) (see the Wildfire discussionunder factor A, below, for furtherinformation on the 2008 post-wildfireassessment efforts).

Monitoring efforts and results in Utahthat have been used to inform this statusassessment include: (a) census effortsconducted in 2004 and 2005 at portionsof 2 EOs (Service 2008b, 17 pp.); (b)installation of 4 small chicken-wireexclosure cages over 5 individual plantsin 2004 to monitor effects of a waterlineconstruction project (all individualswere still present in 2007) (Hardy 2008,pp. 12); (c) documentation of 2individual plants within a 300-foot long

belt transect in 2006 (scheduled to beresurveyed in 2010 (Hardy 2008, p. 2));

(d) establishing a study plot in 2007near a waterline constructed in 2004that includes 231 A. anserinusindividuals, which may be fenced in thefuture (Hardy 2008, p. 1); and (e)conducting field inspectionsat 10 sitesduring the 2008 post-wildfire re-censuseffort (Service 2008c, Table 2, Map 2).

Summary of Factors Affecting theSpecies Rangewide

Section 4 of the Act (16 U.S.C. 1533)and implementing regulations at 50 CFR424, set forth procedures for addingspecies to the Federal Lists ofEndangered and Threatened Wildlifeand Plants. Under section (4) of the Act,we may determine a species to beendangered or threatened based on anyof the following five factors: (A) Thepresent or threatened destruction,modification, or curtailment of habitator range; (B) overutilization forcommercial, recreation, scientific, or

educational purposes; (C) disease orpredation; (D) the inadequacy ofexisting regulatory mechanisms; or (E)other natural or manmade factorsaffecting its continued existence. Inmaking this finding on a petition to listAstragalus anserinus, informationregarding the status of, and threats to, A.anserinus in relation to the five factorsprovided in section 4(a)(1) of the Act isdiscussed below.

Factor A. The Present or ThreatenedDestruction, Modification, orCurtailment of Its Habitat or Range

Wildfire

Organisms adapt to disturbances suchas historical wildfire regimes (firefrequency, intensity, and seasonality)with which they have evolved (Landreset al. 1999, p. 1180), and different rarespecies respond differently to wildfire(Hessl and Spackman 1995, pp. 190).In general, fire regimes within forest andsteppe habitats in the western UnitedStates have been highly disrupted fromhistorical patterns (Whisenant 1990, pp.410; DAntonio and Vitousek 1992, pp.6387; Weddell 2001, pp. 124). In

some instances, fire suppression hasallowed grasslands to be invaded bytrees (Burkhardt and Tisdale 1976, pp.472484; Lesica and Martin 2003, p.516), and in many grassland and shrubhabitats, fire frequencies have increaseddue to the expansion and invasion ofannual nonnative grasses (Whisenant1990, pp. 410; DAntonio and Vitousek1992, pp. 6387; Hilty et al. 2004, pp.8996). These invasive annualnonnative grasses become established inunvegetated areas that would normallyseparate native vegetation, dramatically

increasing the ability of wildfire tospread.

Our understanding of the historicalwildfire regime in the Goose Creekdrainage, and specifically withinAstragalus anserinus habitat, is limited.In general, the average wildfire returninterval within the sagebrush-steppeecosystem as a whole has been reduced

from between 60 and 110 years, to oftenless than 5 years (Whisenant 1990, p. 4;Wright and Bailey 1982, p. 158; Billings1990, pp. 307308; USGS 1999, pp. 19; West and Young 2000, p. 262). Recentwildfires often tend to be larger and

burn more uniformly across thelandscape, leaving fewer unburnedareas, which can affect the post-firerecovery of native sagebrush-steppevegetation (Whisenant 1990, p. 4; Knickand Rotenberry 1997, pp. 287, 297;Brooks et al. 2004, pp. 682683). Theresult of this altered wildfire regime has

been the conversion of vast areas of

sagebrush-steppe ecosystem intononnative annual grasslands (USGS1999, pp. 19). The proportion ofannuals in the sagebrush-steppeecosystem increases dramatically athigher fire frequencies, while all othervegetative life forms decrease.Sagebrush can reestablish from seedfollowing fire, however the seeds areshort-lived and if a second fire occurs

before the new plants produce seed (4to 6 years), the species may face localextirpation. This would be less of aproblem if the fires occurred overrelatively small areas, because seed fromadjacent unburned areas would be

naturally transported back into burnedareas. As fires become larger, theopportunity for seed migration into

burned areas is dramatically decreased(Whisenant 1990, p. 89). Based on ourobservations, Astragalus anserinusseedling germination does not appear to

be stimulated by wildfire. Accordingly,fewer individuals and fewer seedswould be available for recruitment ifwildfire were to return before thespecies is able to recover from earlierwildfire impacts to the population. As aresult, there would be a correspondingdecline in the overall number of

individuals.Wildfire was not documented withinAstragalus anserinus habitat prior to2000 (A. Feldhausen, in litt. 2007, p. 3;R. Hardy, Salt Lake City BLM, in litt.2008, p. 1), although undoubtedly theyoccasionally occurred in the past.Astragalus anserinus habitat is normallysparsely vegetated (e.g., typically 10 to30 percent total vegetative cover), whichlikely makes it less vulnerable towildfire because of the lack of fuels tosustain fire over large areas. We areaware of a wildfire that occurred in A.



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anserinus habitat in Idaho in 2000, andanother wildfire that occurred inNevada and Utah in 2007. The 2000Idaho wildfire affected two EOs (EO 007and EO 009), however at the time, EO009 had not been documented and A.anserinus was not affected by the 2000wildfire at EO 007 (A. Feldhausen, inlitt. 2007a, p. 11). Accordingly, before

2008, we had no pre-wildfire data withwhich to assess the impact of wildfireson A. anserinus. Our knowledge of theeffects from wildfire was limited toobservations at EO 009 from 2004.Based on the best available information,EO 009 is made up of 3 separateoccupied sites that contain 10, 36, and749 individuals based on 2004 surveys/census efforts. The EO 009 site with 749individuals is within a sparselyvegetated slope with mature junipersand shrubs, and may not have burnedduring the 2000 wildfire.

Based on pre-fire data, a single

wildlfire in 2007 in Nevada and Utahcompletely burned 3 EOs and portionsof 5 other EOs containing approximately53 percent of all known Astragalusanserinus individuals (31,500 of 60,000individuals). The 2007 wildfire also

burned 25 percent of the knownoccupied habitat (100 acres (ac) (41hectares (ha)) out of an estimated 400 ac(164 ha)) (Service 2008c, Table 1).

In Nevada, 3 EOs were completelywithin the burned area footprint (1,512total individuals), and three other EOswere partially burned, but had anestimated loss of approximately 72percent of the individuals within those

3 EOs (5,394 of 7,508 individuals). InUtah, portions of two EOs were burnedin the wildfire (EOs 001 and 009). Thewildfire in EO 001, which containedmore than 60 percent of the knownindividuals (37,000 of 60,000individuals), was estimated to have

burned approximately 40 percent of theknown individuals (24,000), and

approximately 18 percent of the totaloccupied acreage (71 ac (29 ha)) (Service2008b, 17 pp.). Please note that since sixof the 10 currently known EOs inNevada were not discovered until 2006(EOs 005 through 010), and onlypopulation estimates and point datahave been collected, the total number ofindividuals and the acreage affected by

the 2007 wildfire are only estimates.Estimating the number of individualsand acres with greater precision isdifficult because of the various methodsthat have been employed by priorsurvey and census efforts.

Based on initial field visits andreports following the 2007 wildfire(Howard 2007, pp. 12), we initiallyunderstood that the wildfire burnedintensely and almost continuouslyacross the landscape. However, our2008 field inspection determined thatthe wildfire burned as a mosaic ratherthan continuously, and did not affectsome small patches ofAstragalusanserinus occupied habitat. Weobserved that 21.3 percent, 81.1 percent,and 94.6 percent of the total acreage was

burned at 3 A. anserinus sites, howeverestimates were not made for 2 othersites within the burned area perimeterthat were only partially burned (Service2008c, Table 2). Our inspection alsodocumented the bunchgrassesHesperostipa comata (needle andthread), Poa secunda (Sandbergs

bluegrass), Pascopyron smithii(westernwheatgrass), Agropyron cristatum(crested wheatgrass), and Achnatherum

hymenoides (Indian ricegrass), as wellas the shrub Chrysothamnusviscidiflorus (green or yellowrabbitbrush) re-sprouting from roots thatsurvived the 2007 wildfire. Thesespecies generally made upapproximately 20 percent of the totalvegetative cover at the burned sites, andit was estimated that 75 to 90 percent of

the bunchgrasses had survived thewildfire (M. Mancuso, MancusoBotanical Services, in litt. 2008, p. 1).

In June, 2008, we conducted post-wildfire re-census efforts to specificallyevaluate the effects of the 2007 wildfireand determine the response ofAstragalus anserinus to this event. Wecounted individual plants at 12 siteswhere we had count data from either2004 or 2005, including Nevada EO 001,Nevada EO 004, and 10 sites withinUtah EO 001 (which represents thelargest EO). Three of the sites that weresurveyed were not burned, 5 of the siteswere partially burned (including UtahEO 001417 which supported 7,486individuals prior to the fire based on2005 data), and 4 of the sites werecompletely burned. Using pre-2007information, we estimate that weresurveyed habitat containingapproximately half of the estimated31,500 individuals burned in the 2007

wildfire (Service 2008c, Tables 1 and 2).Generally, individual plant counts inalmost all burned and unburned areaswere less than those recorded in 2004and 2005.

Table 3 provides pre- and post-firesurvey data from the 12 sites. For the 3unburned sites, the number ofindividuals increased by 5.4 percent atthe first site (652 in 2004 to 687 in2008), decreased by 76.3 percent at thesecond site (1,458 in 2004 to 346 in2008), and decreased by 79.0 percent atthe third site (3,081 in 2005 to 647 in2008) (Service 2008c, Table 2). For the

4 sites that completely burned, thenumber of individuals decreased by94.9 percent at the first site (3,695 in2005 to 188 in 2008); 98.1 percent at thesecond site (314 in 2005 to 6 in 2008);98.2 percent at the third site (1,115 in2005 to 20 in 2008), and 100 percent atthe fourth site (224 in 2005 to 0 in 2008)(Service 2008c, Table 2).

TABLE 3. CENSUS RESULTS FROM THE 2008 POST-WILDFIRE SURVEYS.

EO Number andSite Number

Burned orUnburned

2004 or 20052004/2005Number ofIndividuals

2008 Number ofIndividuals

IndividualsPercent Change

2004 or 2005Percent Area

Burned

N0041 Unburned 2004 652 687 +5.4

U00173 Part-Burned 2004 1,742 1,134 -34.9 21.3

N0011 Part-Burned 2004 541 173 -68.0 unknown

U00161 Unburned 2004 1,458 346 -76.3 0

U001435 Unburned 2005 3,081 647 -79.0 0

U001417 Part-Burned 2005 7,486 772 -89.7 94.6

U001433 Part-Burned 2005 349 31 -91.1 unknown



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TABLE 3. CENSUS RESULTS FROM THE 2008 POST-WILDFIRE SURVEYS.Continued

EO Number andSite Number

Burned orUnburned

2004 or 20052004/2005Number ofIndividuals

2008 Number ofIndividuals

IndividualsPercent Change

2004 or 2005Percent Area

Burned

U001430 Part-Burned 2005 175 13 -92.6 81.1

U001NV1 Burned 2005 3,695 188 -94.9 100

U001412 Burned 2005 314 6 -98.1 100

U001NV2 Burned 2005 1,115 20 -98.2 100

U001434 Burned 2005 224 0 -100.0 100

During our field surveys at the 5 sitesthat were partially burned, we observeda 34.9 percent to 92.6 percent decrease

between the number ofAstragalusanserinus individuals counted in 2004or 2005 and the number counted in2008. The sites that had the most

burned area generally reflected largerdecreases in the number of individualplants (Table 3) (Service 2008c, Table2). Extant A. anserinus individuals werealso more frequently associated withunburned areas in the partially burnedsites. For example, approximately 94.6percent of the occupied area within siteU001417 was burned during the 2007wildfire (this site represented the sitewith the most individuals counted priorto the 2007 wildfire (7,486)). Weobserved that 562 of the 772 individualscounted in U001417 in 2008 (68.1percent) occurred in the 5.4 percent ofthe site that did not burn. Prior to the2007 wildfire, A. anserinus densities

were generally higher within the moresparsely vegetated areas of occupiedsites. It is likely that the number ofindividuals detected within the burnedand unburned areas was influenced bytheir pre-wildfire distribution,particularly since sparsely vegetatedareas were less likely to burn. Becausethe density of individuals at anyparticular site was not measured at afine enough resolution in the 2004,2005, or 2007 surveys, it is difficult toconclusively compare pre-2007 wildfiredensities to post wildfire densities.

We also compared the acreage

occupied by Astragalus anserinusbetween that recorded during the 2004and 2005 census efforts and what weobserved in June 2008. The occupiedacreage decreased at each of the 12 sites,which included both burned andunburned areas, with a range of 37.9 to100 percent (Service 2008c, Table 2).The occupied acreage at the 3 sites thatdid not burn decreased 62.1 percent,60.5 percent, and 77.4 percent (average= 66.6 percent); the reason for thedecrease is unknown. The occupiedacreage at the 5 partially burned sites

decreased 37.9 percent, 59.9 percent,97.3 percent, 86.8 percent, and 99.4percent (average = 73.3 percent). Theoccupied acreage at the 4 sites thatcompletely burned decreased 90.2percent, 77.0 percent, 96.0 percent, and100 percent (average = 90.8 percent)(Service 2008c, Table 2). Since explicitdata collection protocols were notestablished to differentiate between mappoints at which an individual wasrecorded and map polygons whichindicate an area within which one ormore individuals were recorded, weconsidered plants to be within the samepolygon if they were within 33 to 66 ft(10 to 20 m) of one another. For thisreason, determining fire effects bycomparing the burned, unburned, andpartially burned acreage is not asaccurate as comparing the numbers ofindividuals that were actually counted.

Despite the significant declines in thenumber of individuals and occupied

acreage detected in the 2008 surveys,some Astragalus anserinus individualsdid survive the effects of the fire. Plantscan 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 Smith2000, p. 33). Field surveys conducted inNovember 2007 (after the 2007 wildfire),documented that most of the above-ground vegetation had been removed atseveral A. anserinus sites. During thesubsequent 2008 field surveys, weobserved that some adult plants thatsurvived inside burned areas were

attached to large woody roots that likelysurvived the wildfire. This suggests thatthe A. anserinus individuals thatsurvived the 2007 wildfire likely re-sprouted after the wildfire. IfA.anserinus is able to remain dormantduring a growing season, the low plantnumbers we observed in 2008 inunburned sites may indicate that someplants were dormant at that time,although we do not have anyinformation regarding this capability.

We also compared the number ofAstragalus anserinus seedlings counted

in 2008 between burned areas and areasthat did not burn. We observed thatseedlings made up 11.4 percent ofA.anserinus plants (76 of 665) in burnedareas, 11.5 percent (23 of 200) inpartially burned areas, and 2.1 percent(68 of 3,222) in unburned areas (Service2008a, Table 1). Seedlings can becomere-established from surviving plants,seed dispersal from off-site plants,wildfire stimulated seed banks, orplants that re-sprout after a wildfire(USFS 2000, p. 33). The increasednumber of seedlings within burned andpartially burned areas may demonstratethat seed germination was stimulated bythe 2007 wildfire. However, even if thisis true, this response did not offset theobserved individual plant lossesresulting from the 2007 wildfire. We areunaware of any available information onA. anserinus seed bank longevity, anddo not fully understand the effectwildfire may have on this species. Seed

bank studies for other Astragalusspecies indicate that the group generallypossesses hard impermeable seed coatswith a strong physical germination

barrier. As a result, the seeds aregenerally long-lived in the soil and onlya small percentage of seeds germinateeach year (summarized in Morris et al.2002, p. 30). However, we do not knowif the seed germination strategy for otherAstragalus species is comparable to thatemployed by A. anserinus.

We observed an average 50 percentdecline in the number ofAstragalusanserinus plants counted at the 3 sites

that were not burned in the 2007wildfire, compared to pre-fire site datafor those areas. For sites that werecompletely burned by the 2007 wildfire,average plant numbers declined 97.8percent from the number of individualscounted in 2004 or 2005. In some plantspecies, seed dormancy is broken bywildfire (e.g., Pinus contorta, lodgepolepine), and after a wildfire numerousseedlings sprout because this seeddormancy has been broken. However,we did not see a significant number ofnew seedlings within burned areas.



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Because of the low numbers of observedindividuals and the lack of a source fora large flush of seedlings, it is likely thatA. anserinus recovery will depend onthe successful re-colonization of burnedareas. Because of the generally lownumber of seedlings counted, wheredata are available, we suspect that thisre-colonization may take several years

and be dependent upon suitableenvironmental conditions.

We believe that wildfire frequencywill increase within Astragalusanserinus habitat. Wildfire returnintervals in the sagebrush-steppeecosystem, which includes the GooseCreek drainage, have been significantlyreduced from between 60 and 110 yearsto often less than 5 years. The fact thatthe 2007 wildfire was the secondwildfire recorded within a 7yearperiod in the Goose Creek drainage,with no previously recorded wildfires inthis area, appears to present supporting

evidence for increased fire frequency.Wildfire kills Astragalus anserinus, andseedling germination does not appear to

be stimulated by wildfire. Accordingly,increased fire frequency will result infewer A. anserinus individuals, and lessseed availability for recruitment. Theongoing and cumulative effects ofwildfire on A. anserinus include asubstantial reduction in the amount ofavailable habitat, and range-widepopulation-level effects caused by theloss of approximately 98 percent of theindividual plants in the burned areas(which were roughly 53 percent of thepre-2007 wildfire total known

individuals). Future wildfires in thearea will likely result in similardetrimental effects on the remainingpopulation.

It is likely that Astragalus anserinusrecovery will depend on the successfulre-colonization of burned areas, whichwill probably occur slowly over time.However, because wildfire frequencyhas increased in this area, recovery may

be constrained by additional wildfiresin the relatively near future. Therefore,we find the magnitude of this threat to

be high.

Wildfire Management

Wildfire management can includeprescribed burning, and activitiesassociated with fighting wildfires suchas the construction of fire lines andstaging areas, retardant application, andpost-wildfire restoration efforts such asdisking and seeding. In 2008, diskingand seeding associated with soilstabilization activities occurred overportions of 11 Astragalus anserinus sitesin Utah in response to the 2007 wildfire(Service 2008c, Tables 24, Map 4;Service, in litt. 2008, photos 13). It is

likely that numerous individual plantswere lost to site re-seeding efforts androad construction activities. We alsoobserved in some cases that A.anserinus root systems had beenexposed, and believe that it is likely thatindividual plants were turned over and

buried during the disking operations.These actions likely killed individual

plants, thereby compounding theongoing detrimental effects of thewildfire itself on the A. anserinuspopulation.

Firefighting Activities

Firefighting activities such asprescribed burning, road and fire lineconstruction and retardant applicationcan destroy habitat and kill or injureindividual Astragalus anserinus plants.Such activities occurred during theresponse to the wildfire in 2007.Advance A. anserinus surveys were notconducted because of the immediateneed to respond to the 2007 wildfire (M.Gates, Salt Lake City BLM, in litt.2008a). During a brief field inspection ofthe area affected by firefightingactivities prior to our 2008 post-firesurveys, we observed that at least onenew road had been constructed along aridge, and that several fire lines had

been excavated by hand adjacent to A.anserinus habitat. We also observed thata wide fire line had been constructed

between 2 known EOs. During our 2008post-wildfire surveys over 18 A.anserinus occupied sites, we observedthat fire retardant had been applied at1 site over an area approximately 10 ft

(3 m) in radius (U001435). We alsoobserved that a new access road had

been constructed through site U00173, and evidence of tire tracks inoccupied areas at site U001433.

One study of the effects of fireretardant chemical (Phos-Chek G75-F)and fire suppressant foam (Silv-Ex)application, alone and in combinationwith fire, on Great Basin shrub steppevegetation found that growth,resprouting, flowering, and incidence ofgalling insects on Chrysothamnusviscidiflorus (yellow rabbitbrush) andArtemisia tridenta (Big sagebrush) were

not affected by any chemical treatment.In general, the study found that speciesrichness declined, especially after Phos-Check application, but by the end of thegrowing season, species richness did notdiffer between treated and control plots(Larson et al. 1999, p. 115). We areunaware of the specific retardant usedin the 2007 fire response, or whether A.anserinus would be similarlyunaffected. However, based on thelimited extent of the area that wastreated with retardant, we do notanticipate any significant long-term

impacts to the overall A. anserinuspopulation. In addition, since advanceA. anserinus surveys were notconducted because of an immediateneed to respond to the wildfire, we donot know if the other activitiesadversely affected the species. Some firefighting activities could present a futurethreat to A. anserinus, depending on

their specific location and scale;however, we are unable to assess themagnitude of those potential threats atthis time.

Post Wildfire Emergency Stabilizationand Restoration

Post-wildfire restoration activities canalso destroy habitat, kill or harmindividuals, and introduce nonnativespecies, which may outcompeteAstragalus anserinus for resources. Thefollowing is a discussion of restorationactivities that occurred after the 2008fires.

2007 Wildfire EmergencyStabilization and Restoration in Nevada:Following the 2007 wildfire season, theBLM Elko Nevada Field Office (BLM-Nevada) developed a soil stabilizationplan for implementation in 2008 thatincluded reseeding several areasaffected by the fire. A native grassrestoration seeding effort was plannednear EO 005, but was not conducted(Howard 2007, p 3). Post-fire aerialseeding ofArtemisia tridentata var.wyomingensis (Wyoming sagebrush),which is native to Goose Creek, wasundertaken within drainages at or nearthe site instead of the native grass

restoration seeding effort (K. Fuell, ElkoBLM, in litt. 2008, p. 1). This action may

be beneficial to Astragalus anserinus,however we are unaware of the specifictreatment locations, whether the effortswere successful, or whether theyaffected A. anserinus in EO 005.

2007 Wildfire EmergencyStabilization and Restoration in Utah:Restoration seeding activities in Utahwere conducted in late May and early

June, 2008, as part of an EmergencyStabilization Plan (ESP) that wasdeveloped by BLM to treat areas affected

by the 2007 wildfire. A fencing project

and juniper removal chaining efforts(using a chain connected between twotractors) were included as elements ofthis plan. Under the ESP, disk seedingwith a mix of native and nonnativespecies (see Nonnative InvasiveSpeciesseeded below) wasconducted within Astragalus anserinushabitat in an area west of Grouse CreekRoad to stabilize the soils, preventerosion, and minimize competition byBromus tectorum (cheatgrass) in the

burned area. Areas to be avoided wereidentified in advance with flagging to



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prevent impacts to A. anserinus fromplanned juniper removal chainingoperations and seeding efforts (M. Gates,in litt. 2008b, p. 1). However, not all A.anserinus sites were avoided.

The rangeland drills employed in theUtah seeding effort were fitted withmetal cutting discs measuring at least1.0 ft (0.30 m) to 1.5 ft (0.46 m) in

diameter, that were spaced onapproximate 8 inch (20 centimeter)centers. The tractors used in therestoration activities would generallypull two rangeland drills at once,

breaking the soil horizon to a depth ofapproximately 5 inches (13 centimeters)and a width of roughly 20 ft (6.1 m)(Service, in litt. 2008, p. 4, 5). Althoughliving Astragalus anserinus individualswere observed between disk furrowsduring our site inspections (Service, inlitt. 2008, p. 1114), we did not observeany individual plants within the diskfurrows themselves. Our assumption is

that any A. anserinus individuals thatmay have been previously established inthese areas were turned over and buried

by the furrowing activities.The above drilling and seeding

activities were conducted one weekbefore our 2008 re-census surveys. Sincethe work had been recentlyaccomplished, we were able to observeevidence of several live Astragalusanserinus individuals whose woodyroots had been exposed during thedrilling effort. It is unlikely that theseindividuals with exposed roots willsurvive the physical and physiologicalstress of that exposure (Service, in litt.

2008, p. 12, 14). At two sites, thedrilling and seeding efforts affectedclusters of live A. anserinus individualsthat had not been exposed to wildfire(Service 2008c, Maps 4, 9). During our2008 surveys, we were unable toquantify the direct effects of seedingefforts to A. anserinus for severalreasons: 1) the wildfire reduced plantnumbers such that there were very fewplants left with which to analyze effects,2) it was difficult to separate the effectsfrom drilling and seeding from thoseassociated with the wildfire, and 3)many of the 2004 and 2005 census

polygons did not completely align withthe areas that were drilled and seeded,which made comparisons difficult.Because there were no post-wildfireproject-specific surveys conducted inadvance, it is possible that the remedialdrilling and seeding efforts in Utahaffected previously unknown andunsurveyed A. anserinus sites.

Although the ESP included plans toremove dead juniper trees from several

burned areas near Astragalus anserinushabitat by using a chain connected

between two tractors, we did not

observe any evidence that this activityhad been conducted during our June2008 field inspection.

Summary: During our 2008 post-wildfire re-census in Utah, wedocumented 11 occupied sites withinUtah EO 001 (the largest knownAstragalus anserinus EO) that wereimpacted by wildfire management

actions (Service 2008c, Table 3). The 11affected sites contained an estimated11,000 individual plants (representing18 percent of the estimated pre-firerangewide population and 34.5 percentof the pre-fire population numberswithin burned areas). On average, 47.1percent of the total occupied area of asite was seeded (Service 2008c, Tables1, 4), with a range of 13.6 percent to 100percent of the occupied acreage at eachof the 11 sites affected by disking andseeding activities (Service 2008c, Table4). The 11 sites comprised roughly 13percent (54 of 405 ac (22 of 164 ha)) of

the total area rangewide, with roughly25 ac (10 ha) or 6 percent of the totalarea rangewide being impacted bydisking and seeding activities (Service2008c, Table 4). It is likely that some A.anserinus individuals that wereestablished in these areas were killedeither because of mechanical damage or

burial during the disking operations.However, we did see live plants

between the furrows that appearedintact and are likely to survive. Because4 of the 11 sites were not surveyed in2004 and 2005 (U00162, U00163,U00164, and U0016New), we donot have reliable baseline acreage

estimates for these areas. The seedingefforts conducted under the ESPaffected more than 50 percent of theoccupied acreage at site U001417, thesite with the highest number ofindividuals counted in 2005 (7,486plants). In addition, 117 of the 772individuals (15.2 percent) counted atthis site in 2008 were within areasimpacted by the seeding activities(Service 2008c, Tables 3, 4).

We were unable to quantify the directeffects of remedial seeding activities toAstragalus anserinusbecause there wereso few plants left after the 2007 wildfire,

and it was difficult to differentiate thedrilling and seeding effects from the fireeffects. However, it is likely thatnumerous individual plants were lost

because of the post-wildfire stabilizationefforts. The effects of wildfire controlactivities and seeding efforts weredetrimental to several affected A.anserinus sites and may continue to bedetrimental because of the overallreduced recruitment capacity. Thiscould be exacerbated if future wildfiresresult in similar or more aggressive post-fire remedial seeding activities in areas

occupied by A. anserinus, which couldnegatively impact the population byfurther reducing the number ofindividuals. However, the magnitude ofthat potential impact could vary widely,depending on the specific location andscale of activity and the specific A.anserinus EO affected. Therefore, we areunable to assess the magnitude of those

potential threats at this time.Nonnative Introduced SpeciesUnseeded

Invasive nonnative plants (weeds)invade and alter diverse nativecommunities, often resulting innonnative plant monocultures thatsupport little wildlife. Many experts

believe that following habitatdestruction, invasive nonnative plantsare the next greatest threat to

biodiversity (Randall 1996, p. 370).Invasive nonnative plants alter differentecosystem attributes includinggeomorphology, fire regime, hydrology,microclimate, nutrient cycling, andproductivity (Dukes and Mooney 2004,p. 4). Invasive nonnative plants can alsodetrimentally affect native plantsthrough competitive exclusion,alteration of pollinator behaviors, nichedisplacement, hybridization, andchanges in insect predation. Examplesare widespread among taxa andlocations or ecosystems (DAntonio andVitousek 1992, pp. 7475; Olson 1999,pp. 618; Mooney and Cleland 2001, pp.54465451).

Nonnative plants that were notintentionally seeded and are known to

occur at Astragalus anserinus sitesinclude Alyssum desertorum (desertmadwort), Bromus tectorum(cheatgrass), Descurainia sophia(flixweed), Euphorbia esula (leafyspurge), and Halogeton glomeratus(halogeton). In 2008, we also locatedone Hyoscyamus niger(black henbane)individual within one A. anserinus site.In previous years, this species had only

been observed as a few plants alongGoose Creek road. With regard to theabove nonnative species, the two ofmost concern to A. anserinus are B.tectorumbecause of possible effect in

altering the wildfire regime (see Wildfireabove), and E. esulabecause of itsinvasive capabilities (DiTomaso 2000, p.255).

Prior to the 2007 wildfire, Bromustectorum was observed throughout therange ofAstragalus anserinus, but wasgenerally encountered at low density.Bromus tectorum is documented at all 5EOs in Idaho, and 3 of the 4 EOs inUtah. Although habitat information isavailable for only 4 of the 10 EOs inNevada, B. tectorum is documented at 3.One Utah EO has not been visited since



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1990, and nonnative species presencehas not been reported (Service 2008b,17pp.). Bromus tectorum was generallyfound at less than 5 percent cover whenit occurred with A. anserinus, based onestimates from the 2004 and 2005census efforts. At A. anserinus siteswith either a southern slope exposure orwhere livestock trampling was observed

to be more prevalent, the B. tectorumpercent cover was generally higher (e.g.,

between 10 to 20 percent, although ashigh as 70 to 80 percent in a few cases)(Service 2008b, 17 pp.). We do not yetknow how the 2007 wildfire may haveaffected B. tectorum abundance, but areaware that the species often proliferatesas a result of wildfire (DAntonio andVitousek 1992, pp. 7475). The neteffect ofB. tectorum invasion is apositive feedback from the initialcolonization in the interstices of shrubs,followed by fire, to dominance by B.tectorum and more frequent fire

(DAntonio and Vitousek 1992, pp. 7475). However, field observations duringthe 2008 re-census effort suggest that B.tectorum infestations were generallysimilar to what they were before the2007 fire within and outside of areas

burned, although these observationswere not well quantified. This mayimply that B. tectorum may not be athreat to A. anserinus at this time.However, wildfire frequency is tightlylinked with annual grass abundance. Ifwildfire frequency increases, it isexpected that B. tectorum will alsoincrease in abundance.

Euphorbia esula (leafy spurge) is a

perennial forb with a deep andextensive spreading root system, whichcan be up to 20 ft (6 m) long. E. esulaalso spreads by seeds that areexplosively dispersed as much as 15 ft(4.5 m). This species has beendesignated as a noxious weed by thestate of Idaho, meaning it has thepotential to cause injury to publichealth, crops, livestock, land or otherproperty (Idaho Statute 222402). Itreduces species diversity (Selleck et al.1962, p.21; Butler and Cogan 2004, p.308), forms almost homogeneous plantcommunities (Belcher and Wilson 1989,

p. 174), poses a threat to other rare plantspecies such as Platanthera praeclara,(western prairie fringed orchid) (Kirbyet al. 2003, p. 466), and is known from42 of the 44 counties in Idaho (InvadersDatabase System 2008). It generallyforms monocultures with very littlenative vegetation in the areas where itis found in the Goose Creek drainage.

Euphorbia esula has not beendocumented at Astragalus anserinussites in Nevada; however, it has beendocumented at 4 of 5 A. anserinus EOsin Idaho and within the largest EO in

Utah (Service 2008b, 17 pp.). In general,most E. esula sites are small in size,dispersed throughout A. anserinus EOs,and impact only small portions of somesites. In Utah EO 001, E. esula occurs in1 of the 54 known occupied sites, andfrom 10 to 200 ft (3 to 61 m) away at6 other sites (Service 2008b, 17 pp.). InIdaho EO 003, it is present in 13 of the

26 A. anserinus sites, although we havenot established that all of theseexposures directly overlie A. anserinussites. It has also been documented asoccurring in the area at seven other sitesin Idaho (Service 2008b, 17 pp.). Basedon field observations in 2004 and 2005,we estimate that E. esula co-occurs withA. anserinus at less than 2 percent of thetotal range-wide occupied area. In 2008,we observed two leafy spurge sites thathad been disked and seeded during thepost fire restoration effort in Utah(Service 2008c, Maps 7, 9; Service, inlitt. 2008, pp. 1516). This action may

result in a substantial increase in E.esula, since one study examining theeffects of tilling on E. esula found athree-fold increase in the number ofstems per square meter after tilling wasconducted (Selleck et al. 1962, p. 14).

Euphorbia esula control efforts withinthe Goose Creek drainage have beenunderway for several years; from 1999through 2007, control efforts wereconducted at over 500 sites in Idaho.Approximately 40 percent of the E.esula sites documented between 1999and 2006 at Idaho EO 003 were nolonger present in 2007 as a result ofthese efforts (A. Feldhausen, in litt.

2007, pp. 56). However, despite arather intense control program in Utah,the species presence is increasing(Hardy 2005, p. 2). In 2007, increasinglyaggressive control and monitoringefforts targeting E. esula were expandedand implemented at several Astragalusanserinus and Penstemon idahoensissites in Utah and Idaho. BLM-Idahoestablished 11 small study plots todetermine the effectiveness ofE. esulatreatments and to monitor any effects toA. anserinus and P. idahoensis (A.Feldhausen, in litt. 2007a, p. 3). Controlefforts have expanded in the Goose

Creek drainage in Idaho and Utah, butE. esula is still found in or near at least20 A. anserinus sites in 5 EOs in Idahoand Utah (Service 2006b, p.4; A.Feldhausen, in litt. 2007a, p. 3; Service2008b, 17pp.). In the Nevada portion ofthe Goose Creek drainage, BLM-Nevadahas not conducted any invasive speciesmanagement activities and none areplanned (Howard 2007, p. 3).

The potential for Euphorbia esula andBromus tectorum to become establishedthroughout the entire Goose Creekdrainage poses a threat to Astragalus

anserinus. However, infestations of bothspecies are currently limited and do notimpact all occupied sites. In Idaho,control efforts appear to have beeneffective in eliminating E. esula at somesites and in controlling its spread. Werecognize that this threat could becomegreater in the future, if wildfirefrequency increases such that it

promotes the spread ofB. tectorum intoA. anserinus EOs, since B. tectorum ishighly invasive, highly flammable, diesand dries out in the spring, and spreadsfire rapidly (DAntonio and Vitousek1992, p. 74). The magnitude of thepotential threat presented by B.tectorum or E. esula competition wouldvary depending on the location andscale of the infestations, the specific A.anserinus EO(s) affected, and theeffectiveness of any control treatments.As a result, we are unable to assess thelikelihood or magnitude of futurethreats at this time.

Nonnative Introduced SpeciesSeededAgropyron cristatum (crested

wheatgrass) was planted in the GooseCreek drainage before 1970 (Hardy 2005,p. 2; A. Feldhausen, in litt. 2007, p. 10;Howard 2007, p. 3). It was plantedextensively near Astragalus anserinussites during range seeding operations inthe 1950s and 1960s, and also duringwildfire restoration activities conductedwithin the Goose Creek drainage in2007. Although A. cristatum is by farthe most common intentionally seedednonnative species, other nonnativespecies have also been introduced,

including Agropyron fragile (VavilovSiberian wheatgrass), Elymus junceus(Russian wildrye), Elymus lanceolatusssp. lanceolatus (Critana thickspikewheatgrass), Linum perenne (Apar

blueflax), Medicago sativa (Ladakalfalfa), and Thinopyrum ponticum (=Agropyron elongatum, tall wheatgrass)(M. Gates, in litt. 2008e, p. 1; R. Hardy,in litt. 2008, p. 1).

Agropyron cristatum is often used forrangeland seedings because seed iswidely available, it establishes easily,provides suitable forage for livestock,provides some erosion control, and

controls competition from otherinvasive nonnative plants (Walker andShaw 2001, p.56). A. cristatum isextremely competitive and can out-compete other vegetation in severalways (Pellant and Lysne 2005, pp. 8283). A. cristatum seedlings are betterthan some native species at acquiringmoisture at low temperatures (Lesicaand DeLuca 1998, p. 1; Pyke and Archer1991, p. 4; Bunting et al. 2003, p. 82),and A. cristatum plantings are verystable and may inhibit or retard thedevelopment of a native plant



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community (Marlette and Anderson1986, p. 173). Range surveys conductedin 1966 in southern Idaho documentedthat A. cristatum had persisted in someareas for 30 to 50 years and wasspreading into adjacent habitats (Hulland Klomp 1966, p. 7; 1967, p. 227).Increasing plant diversity within A.cristatum sites is challenging, and

requires the implementation ofmeasures to reduce its ability tocompete before native species can beintroduced (Pellant and Lysne 2005, pp.8487).

Prior to 2008, Agropyron cristatumhad been documented at 2 of 5Astragalus anserinus EOs in Idaho, and1 of the 4 EOs in Nevada where we hadhabitat information. A.gropyroncristatum has the largest extent of areain A. anserinus habitat in Utah, whereit was found extensively in the largestUtah EO (EO 001) (Service 2008b, 17pp.). Although not quantified, some of

the new EOs found in 2006 in Nevadawere observed to be occupied by A.cristatum (Howard 2007, p. 3; Smith2007, p.2). However, where both speciesco-occur they are typically separated,with A. cristatum growing on flatterareas and A. anserinus on slopes(Service 2006b, p. 5). Maps obtainedfrom BLM-Utah indicate that A.cristatum had been seeded directly overnumerous A. anserinus EOs, although,

based on our field observations duringthe 2004 and 2005 census efforts, wewere unable to confirm whether thisactually occurred. A. cristatum wasseldom observed where A. anserinus

occurred, which indicates that the steepslopes may have been too difficult toplant and were avoided (Service 2006b,p. 5). We observed that A. anserinusdensity appeared to be higher on flatareas below tuffaceous outcrops whereA. cristatum was not seeded (Service2008b, 17 pp.) than on flat areas whereA. cristatum was seeded. Two sitessurveyed in 2005 (U001NV1 andU001NV2) were unusual in that weobserved a high density ofA. anserinusindividuals in flat areas, as opposed tosloping areas where they are typicallyobserved; these areas had not been

seeded with A. cristatum.Areas disturbed in 2004 duringconstruction of a livestock wateringpipeline that impacted one Astragalusanserinus site in Utah (see Livestock Use

below) were reseeded with severalnonnative species, including Agropyron

fragile, Elymus junceus, Elymuslanceolatus ssp. lanceolatus, Medicagosativa, and Thinopyrum ponticum (M.Gates, in litt. 2008e, p. 1). We areunaware of the effect this activity mayhave had on A. anserinus since we havenot inspected the pipeline subsequent to

its construction. The monitoringassociated with this project was limitedto tracking effects of reseeding on fiveA. anserinus individuals in livestockexclusion cages.

Some areas in Utah that burnedduring the 2007 wildfire were reseededin 2008 with Achillea millefolium(western yarrow)a native forb;

Pascopyrum smithiia native grass;canby bluegrass (Poa secunda Canbar)a native grass; Agropyron cristatumanonnative grass; Elymus junceusanonnative grass; Linum perenneanonnative forb; and Medicago sativaanonnative forb (M. Gates, in litt. 2008b,p. 1). Although the intention of theserestoration efforts was to avoid knownoccupied A. anserinus habitat (M. Gates,in litt. 2008b, p. 1), we observed duringour 2008 survey that 11 sites withinUtah EO 001 (the largest EO) had beendrilled and seeded (Service 2008c, Table3) (see the 2007 Wildfire Emergency

Stabilization and Rehabilitation inUtah section above for more details).We do not fully understand the effects

of the seeding efforts on occupiedAstragalus anserinus areas. Theavailable literature has documented thatAgropyron cristatum, which isfrequently used to stabilize soilsdisturbed by fire, is able to out-competeslower-developing native species

because of its drought tolerance, fibrousroot system, and good seedling vigor(USDA 2006, p. 1). The seedings ofA.cristatum that were conducted prior to2008 were generally separated from A.anserinus areas, and did not appear to

be spreading significantly from the areaswhere the species was planted. Becauseof this separation, populations ofA.cristatum established due to the pre-2008 seeding activities were notconsidered to be a threat to A.anserinus.

The 2008 seeding activities took placedirectly over areas that supportedapproximately 10 percent of the pre-wildfire Astragalus anserinusindividuals, although we are unable toconclusively determine the ongoing orcumulative effect of this activity on A.anserinusbecause of the short time that

has elapsed. In addition, we are notaware of any specific studies on thecompetitive relationship between A.cristatum and any other Astragalusspecies, although A. cristatum is knownto be an effective competitor with otheraggressive introduced plants during theestablishment period (USDA 2006, p. 1).

Summary: The 2008 Agropyroncristatum seeding activities occurreddirectly over areas that supported 18percent of the pre-2007 wildfireAstragalus anserinus rangewidepopulation numbers. We observed A.

anserinus density to be higher in areaswhere A. cristatum was not seeded(Service 2008b, 17 pp.). We believe A.cristatum may be outcompeting A.anserinus in flat areas where A.cristatum was seeded directly over A.anserinus during the 1950s and 1960s.The available literature has documentedthat A. cristatum is highly competitive

with other species (USDA 2006, p. 1).We believe that the reduced populationlevel effects that resulted from the 2007wildfire are being exacerbated by theongoing competitive effects of nonnativeseeded plants that were introduced forrangeland improvement and fireresponse activities. After fullyconsidering each of the above factors,we find the threat presented bynonnative invasive species to A.anserinus to be moderate in magnitude,

because of the likelihood of morefrequent wildfire in the area combinedwith the cumulative population-level

effects on recruitment and recoveryfrom past seeding activities.

Livestock Use (Trampling, WaterDevelopments, and HabitatDegradation)

Threats related to livestock useinclude the physical effects of tramplingof plants, and the effects from rangeimprovement projects and livestockwater developments that degrade habitatand concentrate animals. We areunaware of any research that hasevaluated the effects of livestock use onAstragalus anserinus specifically;however, the effects of livestock on

other plant species is well documented(Milchunas and Lauenroth, 1993, pp.327366; Jones 2000, pp. 155164). Toour knowledge, the effects of livestockuse on A. anserinus pollinators have not

been investigated. However, one studyof another Great Basin Astragalusspecies hypothesized that sheep use andgrazing affected the pollinators for thatspecies through the destruction ofpotential nest sites, destruction ofexisting nests and contents, directtrampling of adult bees, and removal offood resources (Sugden 1985, p. 309).

Livestock use has occurred within the

Goose Creek drainage for more than 150years, although it was likely muchgreater during the late 1800s (Hardy2005, p. 1). The Goose Creek drainagewas a stopping area for pioneerstraveling the California National Trail

because of the availability of water,which increased livestock presence inthe area (Howard 2007, p. 3). However,without pre-livestock baselinepopulation information on Astragalusanserinus, it is difficult to assess theeffects of this activity to the species overtime.



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The presence of livestock trails andevidence of trampling has beendocumented at every Astragalusanserinus EO (Howard 2007, p. 3; A.Feldhausen, in litt. 2007a, p. 4; Service2008b, 17 pp.). In addition, all A.anserinus sites on public land arewithin active livestock grazingallotments. None of these sites have

been fenced or otherwise excluded fromlivestock use, other than someallotments that were recently closed inNevada as a result of the 2007 wildfire(Bluff Creek, Grouse Creek, and LittleGoose Creek) (B. Fuell, Elko BLM, inlitt. 2008, p. 1). One livestock exclusionfence that is proposed for constructioneast of the 2007 wildfire perimeter inUtah has not yet been installed;however, BLM has indicated that they

believe that A. anserinus would belargely undisturbed by this activity (M.Gates, in litt. 2008c, p. 1; 2008d, p. 1).This fence, if installed, would protect A.

anserinus sites from livestock usewithin areas burned by the 2007wildfire.

The intensity of livestock use variesthroughout the Goose Creek drainage,depending on the terrain, location, andproximity to water sources. Forexample, flat areas (especially thoseplanted with Agropyron cristatum)generally receive more livestock usethan the steep tuffaceous outcropswhere A. anserinus normally occurs.Based on field observations from the2004 and 2005 census efforts, weestimate that less than 5 percent of anyparticular A. anserinus site is being

used as livestock trails, with theexception of one site locatedapproximately 328 ft (100 m) from awater development. The fact that A.anserinus individuals have not beenobserved within well-used trailssuggests that plants are lost totrampling. However, the species issometimes observed to be abundantalong trail margins. The relativelysparse vegetation within most occupiedsites and the species apparent ability totolerate some level of disturbance haslikely helped it persist.

Water tanks, placement of salt l

astragalus anserinus - endangered species

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