Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List Abronia ammophila, Agrostis rossiae, Astragalus proimanthus, Boechera (Arabis) pusilla,, 33924-33965 [2011-13910]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 76, Number 111 (Thursday, June 9, 2011)]
[Proposed Rules]
[Pages 33924-33965]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-13910]



[[Page 33923]]

Vol. 76

Thursday,

No. 111

June 9, 2011

Part IV





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; 12-Month Finding on a 
Petition to List Abronia ammophila, Agrostis rossiae, Astragalus 
proimanthus, Boechera (Arabis) pusilla, and Penstemon gibbensii as 
Threatened or Endangered; Proposed Rule

Federal Register / Vol. 76 , No. 111 / Thursday, June 9, 2011 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R6-ES-2011-0023; MO 92210-0-0008-B2]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition To List Abronia ammophila, Agrostis rossiae, Astragalus 
proimanthus, Boechera (Arabis) pusilla, and Penstemon gibbensii as 
Threatened or Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
12-month finding on a petition to list Abronia ammophila (Yellowstone 
sand verbena), Agrostis rossiae (Ross' bentgrass), Astragalus 
proimanthus (precocious milkvetch), Boechera (Arabis) pusilla (Fremont 
County rockcress or small rockcress), and Penstemon gibbensii (Gibbens' 
beardtongue) as threatened or endangered, and to designate critical 
habitat under the Endangered Species Act of 1973, as amended (Act). 
After review of all available scientific and commercial information, we 
find that listing A. ammophila, A. rossiae, A. proimanthus, and P. 
gibbensii is not warranted at this time. However, we ask the public to 
submit to us any new information that becomes available concerning the 
threats to A. ammophila, A. rossiae, A. proimanthus, and P. gibbensii 
or their habitats at any time. After a review of all the available 
scientific and commercial information, we find that listing B. pusilla 
as threatened or endangered is warranted. However, currently listing B. 
pusilla is precluded by higher priority actions to amend the Federal 
Lists of Endangered and Threatened Wildlife and Plants. Upon 
publication of this 12-month petition finding, we will add B. pusilla 
to our candidate species list. We will develop a proposed rule to list 
B. pusilla as our priorities allow. We will make any determinations on 
critical habitat during development of the proposed listing rule. In 
any interim period, we will address the status of the candidate taxon 
through our annual Candidate Notice of Review.

DATES: The finding announced in this document was made on June 9, 2011.

ADDRESSES: This finding is available on the Internet at https://www.regulations.gov at Docket Number FWS-R6-ES-2011-0023. Supporting 
documentation used in preparing this finding is available for public 
inspection, by appointment, during normal business hours at the U.S. 
Fish and Wildlife Service, Wyoming Ecological Services Field Office, 
5353 Yellowstone Road, Suite 308A, Cheyenne, WY 82009. Please submit 
any new information, materials, comments, or questions concerning this 
finding to the above address.

FOR FURTHER INFORMATION CONTACT: R. Mark Sattelberg, Field Supervisor, 
Wyoming Ecological Services Field Office (see ADDRESSES); by telephone 
at 307-772-2374; or by facsimile at 307-772-2358. If you use a 
telecommunications device for the deaf (TDD), please 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 to revise the Federal Lists of Endangered and 
Threatened Wildlife and Plants that contains substantial scientific or 
commercial information that listing the species may be warranted, we 
make a finding within 12 months of the date of receipt of the petition. 
In this finding, we will determine that the petitioned action is: (1) 
Not warranted, (2) warranted, or (3) warranted, but the 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 the Federal 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

    Federal action for Agrostis rossiae and Astragalus proimanthus 
began as a result of section 12 of the original Act, which directed the 
Secretary of the Smithsonian Institution to prepare a report on plants 
considered to be endangered, threatened, or extinct in the United 
States. This report, designated as House Document No. 94-51, was 
presented to Congress on January 9, 1975. That document lists A. 
rossiae as a threatened species and A. proimanthus as an endangered 
species (House Document 94-51, pp. 57, 90, 163). On July 1, 1975, we 
published a notice in the Federal Register (40 FR 27823) accepting the 
Smithsonian Institution report as a petition within the context of 
section 4(c)(2) (petition provisions are now found in section 4(b)(3) 
of the Act), and giving notice of the Service's intention to review the 
status of the plant taxa listed therein.
    As a result of that review, we published a proposed rule on June 
16, 1976, in the Federal Register (41 FR 24523) to determine endangered 
status pursuant to section 4 of the Act for approximately 1,700 
vascular plant taxa, including Astragalus proimanthus. This list of 
plant taxa was assembled based on comments and data received by the 
Smithsonian Institution and the Service in response to House Document 
No. 94-51 and the July 1, 1975, Federal Register publication. General 
comments received in response to the 1976 proposal are summarized in an 
April 26, 1978, Federal Register publication (43 FR 17909). In 1978, 
amendments to section 4(f)(5) of the Act required that all proposals 
over 2 years old be withdrawn. However, proposals already over 2 years 
old were given a 1-year grace period. On December 10, 1979, we 
published a notice in the Federal Register (44 FR 70796) withdrawing 
the portion of the June 16, 1976, proposal that had not been made 
final. This removed both A. proimanthus and Agrostis rossiae from 
proposed status, but retained both species as candidate plant taxa that 
``may qualify for listing under the Act.''
    On December 15, 1980, we published a current list of those plant 
taxa native to the United States being considered for listing under the 
Act; this identified both Agrostis rossiae and Astragalus proimanthus 
as category 1 taxa (45 FR 82480). The Service defined category 1 taxa 
as a taxonomic group for which we presently had sufficient information 
on hand to support the biological appropriateness of these taxa being 
listed as threatened or endangered species (45 FR 82480). On November 
28, 1983, A. rossiae was lowered to a category 2 taxon ``currently 
under review,'' whereas A. proimanthus was moved to the ``taxa no 
longer under review'' list, and given a 3C rank, indicating the species 
was more abundant or widespread than previously believed or not 
subjected to any identifiable threat (48 FR 53640). We defined category 
2 taxa as those for which we had information at that time that 
indicated proposing to list was possibly appropriate, but for which 
substantial data on biological

[[Page 33925]]

vulnerability and threat(s) was not currently known or on file to 
support proposed rules. Boechera (formerly Arabis) pusilla and 
Penstemon gibbensii were added as category 2 taxa during the same 
review (48 FR 53640). These four species retained the same ranking for 
the subsequent review on September 27, 1985 (50 FR 39526). The February 
21, 1990, list kept A. rossiae, B. pusilla, and P. gibbensii as 
category 2 taxa, and reverted A. proimanthus back to a category 2 taxon 
(55 FR 6184).
    The September 30, 1993, review changed the status of Boechera 
pusilla to a category 1 species (58 FR 51144). This review added a 
``status trend'' column. Each species was identified as increasing (I), 
stable (S), declining (D), or unknown (U). The 1993 review added 
Abronia ammophila and assigned it a 2U rank, moved Boechera pusilla up 
to a 1D rank, and listed Agrostis rossiae as 2U, Astragalus proimanthus 
as 2S, and Penstemon gibbensii as 2U (58 FR 51144).
    On February 28, 1996, we proposed discontinuing the designation of 
category 2 species as candidates due to the lack of sufficient 
information to justify issuance of a proposed rule (61 FR 7596). This 
proposal included eliminating candidate status for four of the five 
species addressed in this finding; only Boechera pusilla was proposed 
to remain a candidate (61 FR 7596). This policy change was finalized on 
December 5, 1996, stating that the listing of category 2 species was 
not needed because of other lists already maintained by other entities 
such as Federal and State agencies (61 FR 64481).
    On September 19, 1997, we published a notice of review that 
retained Boechera pusilla as a candidate species (62 FR 49398). 
However, on October 25, 1999, we published a notice of review that 
indicated our intent to remove several species, including B. pusilla, 
from the list of candidate species because evidence suggested that 
these taxa were either more abundant than previously believed or that 
the taxa were not subject to the degree of threats sufficient to 
warrant continuance of candidate status, issuance of a proposed 
listing, or a final listing (64 FR 57534). The change of status for B. 
pusilla was finalized on October 20, 2000, on the basis that regulatory 
mechanisms and changes to management of the associated land reduced or 
eliminated the threats facing B. pusilla and ensured the survival and 
conservation of this species (65 FR 63044).
    On July 30, 2007, we received a formal petition dated July 24, 
2007, from Forest Guardians (now WildEarth Guardians), requesting that 
we: (1) Consider all full species in our Mountain-Prairie Region ranked 
as G1 or G1G2 by the organization NatureServe, except those that are 
currently listed, proposed for listing, or candidates for listing; and 
(2) list each species as either threatened or endangered. The petition 
identified 206 species as petitioned entities, including the 5 species 
we address in this status review. A species ranking of G1 is defined as 
a species that is critically imperiled across its entire range (or 
global range) (NatureServe 2010b, p. 3). A ranking of G1G2 means the 
species is either ranked as a G1 or a G2 species, with G2 defined as 
imperiled across its entire range (NatureServe 2010b, pp. 3-4). The 
petition incorporated all analysis, references, and documentation 
provided by NatureServe in its online database at https://www.natureserve.org/ into the petition. The petition clearly identified 
itself as a petition and included the identification information, as 
required in 50 CFR 424.14(a). We sent a letter to the petitioners, 
dated August 24, 2007, acknowledging receipt of the petition and 
stating that, based on preliminary review, we found no compelling 
evidence to support an emergency listing for any of the species covered 
by the petition.
    On March 19, 2008, WildEarth Guardians filed a complaint (1:08-CV-
472-CKK) indicating that the Service failed to comply with its 
mandatory duty to make a preliminary 90-day finding on their two 
multiple-species petitions--one for mountain-prairie species and one 
for southwest species. We subsequently published two initial 90-day 
findings on January 6, 2009 (74 FR 419), and February 5, 2009 (74 FR 
6122). The February 5, 2009, finding determined that there was not 
substantial scientific or commercial information indicating that 
listing 165 of the 206 petitioned species in the mountain-prairie 
region may be warranted (74 FR 6122). Two additional species were 
evaluated in a January 6, 2009, 90-day finding (74 FR 419), and no 
determination was made on whether substantial information had been 
presented on the remaining 39 species included in the petition (74 FR 
6122). The 5 species covered in this 12-month finding were among the 
remaining 39 species. An additional species was determined to qualify 
for candidate status (73 FR 75175; December 10, 2008). On March 13, 
2009, the Service and WildEarth Guardians filed a stipulated settlement 
in the District of Columbia Court, agreeing that the Service would 
submit to the Federal Register a finding as to whether WildEarth 
Guardians' petitions present substantial information indicating that 
the petitioned actions may be warranted for the remaining 38 mountain-
prairie species by August 9, 2009.
    On June 18, 2008, we received a petition from WildEarth Guardians 
dated June 12, 2008, to emergency list 32 species under the 
Administrative Procedure Act and the Endangered Species Act. Of those 
32 species, 11 were included in the July 24, 2007, petition to be 
listed on a non-emergency basis. Although the Act does not provide for 
a petition process for an interested person to seek to have a species 
emergency listed, section 4(b)(7) of the Act authorizes the Service to 
issue emergency regulations to temporarily list a species. In a letter 
dated July 25, 2008, we stated that the information provided in both 
the 2007 and 2008 petitions and in our files did not indicate that an 
emergency situation existed for any of the 11 species. The Service's 
decisions whether to exercise its authority to issue emergency 
regulations to temporarily list a species are not judicially 
reviewable. See Fund for Animals v. Hogan, 428 F.3d 1059 (DC Cir. 
2005).
    On August 18, 2009, we published a notice of 90-day finding (74 FR 
41649) on the remaining 38 species from the petition to list 206 
species in the mountain-prairie region of the United States as 
threatened or endangered under the Act. We found that the petition 
presented substantial scientific and commercial information for 29 of 
the 38 species, indicating that listing may be warranted for those 
species. The 5 species we address in this 12-month finding were 
included within these 29 species. We also opened a 60-day public 
comment period to allow all interested parties an opportunity to 
provide information on the status of the 29 species (74 FR 41649). The 
public comment period closed on October 19, 2009. We received 224 
public comments. Of these, 38 specifically addressed Abronia ammophila, 
Agrostis rossiae, Astragalus proimanthus, Boechera pusilla, and 
Penstemon gibbensii. All information received has been carefully 
considered in this finding. This notice constitutes the 12-month 
finding on 5 of the 206 species identified in WildEarth Guardians' 
petition dated July 24, 2007, to list Abronia ammophila, Agrostis 
rossiae, Astragalus proimanthus, Boechera pusilla, and Penstemon 
gibbensii as threatened or endangered.

[[Page 33926]]

Summary of Procedures for Determining the Listing Status of Species

Review of Status Based on Five Factors
    Section 4 of the Act (16 U.S.C. 1533) and implementing regulations 
(50 CFR part 424) set forth procedures for adding species to, removing 
species from, or reclassifying species on the Federal Lists of 
Endangered and Threatened Wildlife and Plants. Under section 4(a)(1) of 
the Act, a species may be determined to be endangered or threatened 
based on any of the following five factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, 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 these findings, information pertaining to each species in 
relation to the five factors provided in section 4(a)(1) of the Act is 
discussed below. In considering what factors might constitute threats 
to a species, we must look beyond the exposure of the species to a 
particular factor to evaluate whether the species may respond to the 
factor in a way that causes actual impacts to the species. If there is 
exposure to a factor and the species responds negatively, the factor 
may be a threat, and during the status review, we attempt to determine 
how significant a threat it is. The threat is significant if it drives 
or contributes to the risk of extinction of the species such that the 
species warrants listing as endangered or threatened as those terms are 
defined by the Act. However, the identification of factors that could 
impact a species negatively may not be sufficient to compel a finding 
that the species warrants listing. The information must include 
evidence sufficient to suggest that the potential threat has the 
capacity (i.e., it should be of sufficient magnitude and extent) to 
affect the species' status such that it meets the definition of 
endangered or threatened under the Act.
Findings
Distinct Population Segments
    After considering the five factors, we assess whether each species 
is threatened or endangered throughout all of its range. Generally, we 
next consider in our findings whether a distinct vertebrate population 
segment (DPS) or any significant portion of the species' range meets 
the definition of endangered or is likely to become endangered in the 
foreseeable future (threatened). Section 3(16) of the Act defines a 
species to include only a vertebrate species as a DPS. Therefore, the 
Service's Policy Regarding the Recognition of Distinct Vertebrate 
Population Segments Under the Endangered Species Act (DPS Policy) (61 
FR 4722; February 7, 1996) is not applicable to plants and no 
population segments under the review could qualify as DPSs under the 
Act. Although the Service's DPS Policy is not applicable to plants, we 
do determine in our findings whether a plant species is threatened or 
endangered in a significant portion of its range.
Significant Portion of the Range
    In determining whether a species is threatened or endangered in a 
significant portion of its range, we first identify any portions of the 
range of the species that warrant further consideration. The range of a 
species can theoretically be divided into portions an infinite number 
of ways. However, there is no purpose to analyzing portions of the 
range that are not reasonably likely to be both (1) significant and (2) 
threatened or endangered. To identify only those portions that warrant 
further consideration, we determine whether there is substantial 
information indicating that: (1) The portions may be significant, and 
(2) the species may be in danger of extinction there or likely to 
become so within the foreseeable future. In practice, a key part of 
this analysis is whether the threats are geographically concentrated in 
some way. If the threats to the species are essentially uniform 
throughout its range, no portion is likely to warrant further 
consideration. Moreover, if any concentration of threats applies only 
to portions of the species' range that are not significant, such 
portions will not warrant further consideration.
    If we identify portions that warrant further consideration, we then 
determine whether the species is threatened or endangered in these 
portions of its range. Depending on the biology of the species, its 
range, and the threats it faces, the Service may address either the 
significance question or the status question first. Thus, if the 
Service considers significance first and determines that a portion of 
the range is not significant, the Service need not determine whether 
the species is threatened or endangered there. Likewise, if the Service 
considers status first and determines that the species is not 
threatened or endangered in a portion of its range, the Service need 
not determine if that portion is significant. However, if the Service 
determines that both a portion of the range of a species is significant 
and the species is threatened or endangered there, the Service will 
specify that portion of the range as threatened or endangered under 
section 4(c)(1) of the ESA.

Evaluation of the Status of Each of the Five Plant Species

    For each of the five species, we provide a description of the 
species and its life-history and habitat, an evaluation of listing 
factors for that species, and our finding that the petitioned action is 
warranted or not for that species. We follow these descriptions, 
evaluations, and findings with a discussion of the priority and 
progress of our listing actions.

Species Information for Abronia ammophila

Species Description

    Abronia ammophila is a low-growing, mat-forming perennial herb 
(Clark et al. 1989, p. 7; Fertig 1994, unpaginated; (National Park 
Service (NPS) 1999b, p. 3; Fertig 2000b, unpaginated; Saunders and 
Sipes 2006, p. 76). A. ammophila is a highly restricted endemic 
(occurring only in one location or region) to the Yellowstone Plateau 
(NPS 1999a, p. 1). In addition to the common name of Yellowstone sand 
verbena, A. ammophila has been called Tweedy's sand verbena (Clark et 
al. 1989, p. 7; Marriott 1993, p. 1) and Wyoming sand verbena 
(Integrated Taxonomic Information System 2010a, unpaginated).
    Abronia ammophila has a large taproot (primary root that grows 
vertically downward, not highly branched) that can be over 0.5 meter 
(m) (1.6 feet (ft)) in length, which helps the plant root into the 
loose sand (Whipple 1999, p. 3; Whipple 2002, p. 257; Saunders and 
Sipes 2004, p. 9). Its stems can grow up to 2 to 4 decimeters (dm) 
(0.66 to 1.31 ft) in length; however, this plant is only 2.5 to 10.2 
centimeters (cm) (1 to 4 inches (in.)) tall (Rydberg 1900, p. 137; 
Galloway 1975, p. 344; Fertig 1994, unpaginated; NPS 1999b, p. 3; 
Fertig 2000b, unpaginated; NPS 2000, unpaginated). A. ammophila is 
covered by sticky glands, which result in the plants being covered with 
sand (Coulter and Nelson 1909, p. 175; NPS 1999b, p. 3; NPS 2000, 
unpaginated; Whipple 2002, pp. 257-258; Saunders and Sipes 2006, p. 
76). The leaf blades are succulent (fleshy) and oval or diamond-shaped 
with smooth edges (Fertig 1994, unpaginated; NPS 1999b, p. 3).

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    The flowers of Abronia ammophila are whitish to light pink or light 
green and grow in a capitulum (head-like group of flowers) typically 
containing 4 to 21 flowers (Saunders and Sipes 2006, p. 79). The 
flowers are hermaphroditic (possessing both male and female 
reproductive organs) (Saunders and Sipes 2004, p. 9; 2006, p. 76). As 
with other members of the Nyctaginaceae (the Four O'Clock) family, A. 
ammophila lacks true petals (Saunders and Sipes 2004, p. 9; 2006, p. 
76).

Discovery and Taxonomy

    Frank Tweedy made the first collection of Abronia ammophila in 
1885; however, he labeled it as Abronia villosa (desert sand verbena). 
The collection was from the sandy beaches on the north side of 
Yellowstone Lake at the mouth of Pelican Creek (Tweedy 1886, p. 59). A. 
villosa is a common purple-flowered species of the American southwest 
(Whipple 2002, p. 256). In 1900, Per Axel Rydberg determined that 
Tweedy's sample was sufficiently different from other Abronia to 
warrant recognition as a unique species; he named it Abronia arenaria 
(coastal sand verbena) (NPS 1999b, p. 2; Whipple 1999, p. 3; 2002, p. 
256). However, the name A. arenaria had previously been used (NPS 
1999b, p. 2; Whipple 1999, p. 2; 2002, p. 256). E.L. Greene proposed 
the name A. ammophila for the Yellowstone sand verbena species (Greene 
1900 as cited in Whipple 2002, p. 256).
    The name Abronia ammophila was formally recognized (Coulter and 
Nelson 1909, p. 175); however, midway through the 20th century it was 
combined with Abronia fragrans (snowball sand verbena), a widespread 
western species (Hitchcock et al. 1964 and Despain 1975 as cited in 
Whipple 2002, p. 257). In 1975, a study of the Abronia genus determined 
that the Yellowstone species was unique (Galloway 1975, p. 344; NPS 
1999b, p. 3; Whipple 2002, p. 257). Plant material collected from scrub 
communities of sandy hills near Big Piney, Sublette County, Wyoming, 
also was included under A. ammophila (Galloway 1975, p. 344, NPS 1999b, 
p. 3; Whipple 2002, p. 257). Further examination revealed that the 
specimens from Sublette County are actually Abronia mellifera (white 
sand verbena) (Marriott 1993, pp. 6, 9; Fertig 1994, unpaginated).
    Abronia ammophila is a member of the New World plant family 
Nyctaginaceae that typically lives in warmer climates, such as deserts 
and tropical areas (NPS 2000, unpaginated). The genus Abronia contains 
approximately 20 to 30 species (NPS 1999b, p. 2, Flora of North America 
2010a, unpaginated). Most Abronia occur in the western United States 
and Mexico, but some extend into southern Canada and east into the 
Great Plains and Texas (NPS 1999b, p. 2). A. ammophila is similar to 
Abronia mellifera (Fertig 1994, unpaginated) and Abronia fragrans 
(Flora of North America 2010, unpaginated). We recognize A. ammophila 
as a valid species and a listable entity.

Biology and Life History

    Abronia ammophila starts to flower by the middle of June and 
continues producing flowers until a frost occurs that kills its 
aboveground parts, usually in late August or early September (NPS 
1999b, p. 6; Whipple 1999, p. 3; NPS 2000, unpaginated; Whipple 2002, 
p. 258). This extended blooming period is unusual in comparison to 
other plants in Yellowstone National Park (YNP) (Whipple 1999, p. 3). 
Additionally, unlike many of its associated species, A. ammophila 
continues to flower vigorously even after setting fruit (NPS 1999b, p. 
6; Whipple 2002, p. 258).
    Abronia ammophila is visited by several orders of insects (Saunders 
and Sipes 2004, p. 10; 2006, p. 80). The most frequent visitors to A. 
ammophila are lepidopterans (butterflies and moths) (Saunders and Sipes 
2004, p. 10; 2006, p. 80). Even though Abronia ammophila is visited by 
a diverse range of pollinators, the total number of pollinator 
visitations is extremely low (Saunders and Sipes 2006, p. 81). The low 
level of pollinator visits may be offset by A. ammophila exhibiting a 
mixed-mating system (Saunders and Sipes 2004, pp. 6, 10, 12; 2006, p. 
82). In addition to cross-pollination facilitated by pollinators, A. 
ammophila is able to self-pollinate with or without a pollen vector 
(Saunders and Sipes 2004, pp. 6, 10, 12; 2006, pp. 80-82; Whipple 
2010b, pers. comm.). Self-pollination is highly likely due to the 
floral morphology (the structure of the flower) and the functional 
phenology (life cycle) of A. ammophila (Saunders and Sipes 2006, p. 
81).
    Abronia ammophila is capable of producing large numbers of flowers 
(Saunders and Sipes 2004, p. 13). Seed dispersal mechanisms of Abronia 
ammophila have not been extensively studied. Primary seed dispersal 
appears to occur beneath the parent plant (Saunders and Sipes 2006, p. 
79). Seeds also accumulate in depressions of the sand, where the wind 
has blown them (NPS 1999b, p. 6; Whipple 2002, p. 258). The sticky 
surface of the seeds may facilitate dispersal, for example on the feet 
of waterfowl (NPS 1999b, pp. 6-7; Whipple 2002, p. 258). Water also may 
facilitate dispersal (Saunders and Sipes 2006, p. 79). As A. ammophila 
occurs in locations that are not located adjacent to each other, there 
appears to be an effective method of seed dispersal (NPS 1999b, pp. 6-
7; Whipple 2002, p. 258). However, the longevity of A. ammophila seeds 
in the seed bank in unknown (NPS 1999b, p. 7; Whipple 2002, p. 258).

Habitat

    Abronia ammophila is endemic to YNP, within Park and Teton Counties 
of Wyoming (Whipple 2002, p. 256; Fertig 2000b, unpaginated; Saunders 
and Sipes 2006, p. 76). Specifically, A. ammophila occurs around 
Yellowstone Lake typically within 40 m (131.2 ft) of the shoreline (NPS 
1999b, p. 5; Whipple 1999, p. 3; Fertig 2000b, unpaginated; Whipple 
2002, p. 262). The plant has been found up to 60 m (196.9 ft) inland 
and up to approximately 10 m (32.8 ft) above the high-water line (NPS 
1999b, p. 5; Whipple 1999, p. 3; Fertig 2000b, unpaginated; Whipple 
2002, p. 262). A. ammophila generally occurs above the high-water mark; 
no plants grow in areas that are regularly inundated (NPS 1999b, p. 5; 
Whipple 1999, p. 3; 2002, p. 262). Yellowstone Lake is a high-elevation 
(2,360 m (7,742 ft)), freshwater lake that was formed by volcanic 
activity (Pierce et al. 2007, pp. 131-132; NPS 2006a, unpaginated). The 
lake level was originally 61 m (200 ft) higher than its present level, 
and the level is not entirely stable (Pierce et al. 2007, pp. 131-132; 
NPS 2006a, unpaginated). A. ammophila appears to be able to adapt to 
the continually changing boundaries of its habitat as defined by 
Yellowstone Lake's fluctuations.
    Occurring between the area of beach affected by wave action and the 
more densely vegetated areas inland, Abronia ammophila prefers open, 
sunny, sparsely vegetated sites (NPS 1999b, p. 5; Whipple 2002, p. 262; 
Saunders and Sipes 2006, p. 77). Associated vegetative species include 
Phacelia hastata (silver-leaf scorpion-weed), Rumex venosus (veiny 
dock), Polemonium pulcherrimum (Jacob's-ladder), and Lupinus argenteus 
(silvery lupine) (NPS 1999b, p. 5; Whipple 2002, p. 262; Saunders and 
Sipes 2006, p. 77). A. ammophila loses its competitive advantage on 
more stable soils or in areas where Artemisia tridentata (big 
sagebrush) or Eriogonum umbellatum (sulfur flower buckwheat) occur 
(Whipple 2002, p. 262; Saunders and Sipes 2006, p. 77).
    Abronia ammophila occurs at four locations around Yellowstone Lake; 
these locations are identified as North

[[Page 33928]]

Shore, Rock Point, Pumice Point, and South Arm (NPS 1999a, pp. 3-6; NPS 
1999b, pp. 4-5; Whipple 2002, p. 262). These populations cover an area 
of 0.6 hectares (ha) (1.48 acres (ac)) (Whipple 2011, pers. comm.). The 
populations all occur in loose, unconsolidated (loosely arranged) sand 
with a minimal amount of fines (powdered material), gravel, or organic 
matter (NPS 1999b, p. 5; Whipple 2002, p. 262; Saunders and Sipes 2006, 
p. 77). All sites are located on beach sand except the Pumice Point 
site, which occurs on black sand (NPS 1999b, p. 5; Whipple 2002, p. 
262). Some of the populations occur in horseshoe-shaped, sandy 
depressions (blowouts) (NPS 1999a, p. 3; 1999b, p. 5; Whipple 2002, p. 
262; Saunders and Sipes 2006, p. 77). Additionally, the largest 
subpopulation in the North Shore area--the ``Thermal'' site--is located 
adjacent to a small thermal barren (area where no vegetation grows) 
(NPS 1999a, p. 6; NPS 1999b, p. 6). This area hosts an extremely dense 
population of Abronia ammophila with some of the largest individuals 
(NPS 1999b, p. 6). A. ammophila is able to coexist with thermal 
influences; however, most of the populations grow on ground that is not 
thermally influenced (NPS 1999a, p. 6).

Distribution and Abundance

    Herbarium records show that Abronia ammophila was previously more 
widely distributed along the northern shore of Yellowstone Lake (NPS 
1999b, p. 9; Whipple 2002, p. 258). Locations such as 0.40 kilometer 
(km) (0.25 mile (mi)) west of the mouth of Pelican Creek and several 
locations near the current Fishing Bridge development have been 
recorded as collection locations of A. ammophila (NPS 1999b, p. 9; 
Whipple 2002, pp. 258-259). Many additional areas of the northern 
shoreline provide suitable habitat for A. ammophila, such as west of 
Pelican Creek to the outlet of the Yellowstone River and Mary Bay (NPS 
1999b, p. 9; Whipple 2002, p. 259; Whipple 2010a, pers. comm.). 
Construction of the East Entrance Road and the Fishing Bridge 
campground, an area that was near the current parking area for the 
Fishing Bridge Museum, as well as higher human use may have extirpated 
populations of A. ammophila in these areas (NPS 1999b, pp. 8-9; Whipple 
2002, pp. 258-259; Whipple 2010a, pers. comm.).
    Table 1 below presents available information regarding the four 
populations of Abronia ammophila. The 1998-1999 survey was a rigorous 
population count (NPS 1999a, entire). The other years were generally 
estimates, except for some of the smaller populations where an exact 
count was easily obtained (Correy 2009, entire; Whipple 2010d, pers. 
comm.).

           Table 1--Population Estimates of Abronia ammophila
------------------------------------------------------------------------
     Population  (year of discovery)          Estimated numbers (year)
------------------------------------------------------------------------
North Shore (prior to 1998)..............  Approx. 1,000 (early 1990s).
                                           7,978 (1998-1999) rigorous
                                            count.
                                           Approx. 3,600 (2010).
Rock Point (1998)........................  325 (1998).
                                           120 (2009).
Pumice Point (1998)......................  22 (1998).
                                           1 (2001).
                                           5 (2009).
                                           24 (2010).
South Arm (1998).........................  1 (1998).
                                           3 (2005).
                                           2 (2010).
                                          ------------------------------
    Totals...............................  1,000 (early 1990s) (only
                                            North Shore known).
                                           8,326 (1998-1999) rigorous
                                            count.
                                           2,728 (2009) estimate.
                                           3,626 (2010) estimate.
------------------------------------------------------------------------
References: NPS 1999a, Appendix A; Corry 2009, Table 1; Whipple 2002, p.
  259; 2010d pers. comm.

    The majority of Abronia ammophila is found in the North Shore 
population scattered along a 2.41-km (1.5-mi) stretch of beach on the 
northern shoreline of Yellowstone Lake between the mouth of Pelican 
Creek and Storm Point (NPS 1999a, p. 3; 1999b, p. 4; Correy 2009, p. 
2). This population contains 95 percent or more of all A. ammophila 
(NPS 1999a, pp. 2, Appendix A; Whipple 2002, p. 264; Correy 2009, p. 
4). Prior to surveys conducted between 1995 and 1999, the North Shore 
population of A. ammophila was the only known population (NPS 1999a, p. 
3; Correy 2009, p. 2). Of the additionally discovered sites, two are 
located on the west shore of Yellowstone Lake: One at Rock Point, and 
one at a picnic area 1.6 km (1 mi) west of Pumice Point (NPS 1999a, p. 
5; NPS 1999b, p. 4). Additionally, a single plant was found during 
surveys on the east shore of the South Arm (NPS 1999a, p. 5). Not all 
suitable habitat within YNP has been surveyed (NPS 1999a, pp. 6-7).
    Casual surveys of the North Shore area in the early 1990s estimated 
the population to be around 1,000 plants (Correy 2009, pp. 1-2), with 
the majority of the plants of a large-size class representing mature, 
older plants (NPS 1999a, p. 1; 1999b, p. 7). No seedlings were observed 
(NPS 1999b, p. 7). Extensive surveys during the 1998-1999 field seasons 
conservatively estimated the North Shore population to consist of 7,978 
Abronia ammophila plants, with 45 percent of the population represented 
by young recruitment within the prior 2 years (recruit and medium class 
plants) (NPS 1999a, p. 1). The record high lake levels of 1996 and 1997 
appeared to improve the habitat conditions for A. ammophila by eroding 
the southern edge of the stabilized sand along the northern shoreline 
(NPS 1999b, p. 7; Whipple 2002, p. 265). Although this erosion washed 
away part of the existing habitat, it also improved conditions for 
recruitment of seedlings (NPS 1999b, p. 7; Whipple 2002, p. 265).
    During the 2009-2010 field season, surveys of the North Shore 
population yielded an approximate count of 3,600 A. ammophila plants 
(Correy 2009, p. 3; Whipple 2010d, pers. comm.; Whipple 2011, pers. 
comm.). The North Shore population can be split into four 
subpopulations (Correy 2009, p. 2). Two of these subpopulations had 
comparable population counts during both the 1998-1999 survey and the 
2009-2010 estimate (Correy 2009, pp. 3-4). The remaining two 
subpopulations, the Thermal and Long Skinny groups, had decreased in 
both total area populated and total number of plants (Correy 2009, p. 
5). The central portion of the Thermal group is now bare or mostly bare 
sand due to increased ground temperatures (due to changes within the 
Yellowstone geothermal basin), ground subsidence, increased scouring 
during storms, or a combination of such factors (Correy 2009, p. 5). 
The Long Skinny group also may have been affected by increased ground 
temperatures, particularly on the western end; furthermore, some of the 
habitat may have eroded (Correy 2009, p. 5). Additional factors 
potentially affecting the low population count include many years of 
drought (Whipple 2002, p. 265; Correy 2009, pp. 5-6) and lack of 
rigorous survey methods (Correy 2009, pp. 5-6).
    The Rock Point and Pumice Point Abronia ammophila populations were 
accurately counted in 1998 and 2009 (Correy 2009, Table 1). In 1998, 
the Rock Point population consisted of 324 individual plants; the 2009 
survey counted 120 individual plants (NPS 1999a, p. 6; Correy 2009, 
Table 1). An area of Rock Point surveyed in 1998 had no A. ammophila in 
June, but contained many medium-sized plants later in the summer (NPS 
1999a, p. 6). The Pumice Point population consisted of 22 plants in 
1998, whereas only 5 were counted in 2009 (NPS 1999a, p. 6; Correy 
2009,

[[Page 33929]]

Table 1). In 1998, the Pumice Point population contained a higher 
percentage of large (diameter greater than or equal to 5 up to 30 cm (2 
up to 11.8 in.)) and very large (diameter greater than or equal to 30 
cm (11.8 in.)) plants when compared to the North Shore population 
distribution (NPS 1999a, p. 6). Additionally, the Pumice Point 
population contained 24 plants in the 2010 field survey (Whipple 2010e, 
pers. comm.), which is comparable to the 1998 population count.
    The South Arm population contained only one large Abronia ammophila 
plant when it was discovered in 1998 (NPS 1999a, p. 6). When this site 
was revisited in 2005, the large individual found in 1998 was no longer 
present, but three small A. ammophila plants were present (Correy 2009, 
p. 2). Additionally, during the 2010 field survey, this population 
consisted of two plants (Whipple 2010e, pers. comm.).
    Dead and dying plants were counted during the 1998-1999 field 
surveys. Dead and dying Abronia ammophila plants accounted for 1.3 
percent of the total population (NPS 1999a, Appendix A). Of the dead A. 
ammophila plants, many were large individuals; however, some were 
failed seedlings (NPS 1999b, p. 7). The majority of dead and dying 
plants did not display obvious causes of mortality; they were 
interspersed throughout the communities (NPS 1999b, p. 7). 
Additionally, stressed A. ammophila plants are able to recover and put 
out new growth later in the season (NPS 1999b, p. 7).
    The Wyoming Natural Diversity Database (WNDD) has designated 
Abronia ammophila as a plant species of concern with ranks of G1 and S1 
(Heidel 2007, p. 1). This designation indicates that A. ammophila is 
considered to be critically imperiled because of extreme rarity (i.e., 
often less than five occurrences (a location where a plant or plants 
has been recorded)) or because some factor makes it highly vulnerable 
to extinction both at the global and State level; however, this ranking 
does not grant A. ammophila any special status under State legislation 
(WNDD 2009, unpaginated; WNDD 2010, unpaginated). Since A. ammophila is 
endemic to Wyoming, the Wyoming occurrences encompass the entire global 
range. Additionally, YNP considers A. ammophila to be a sensitive 
species of concern; therefore, it evaluates effects to this species in 
conjunction with any project or action that has the potential to affect 
the plant (Whipple 2011, pers. comm.).

Trends

    Natural fluctuations in the Abronia ammophila population from year 
to year or even within a season are not understood (Correy 2009, p. 6). 
From the first population estimates of the North Shore population in 
the early 1990s to the more rigorous survey conducted in 1998-1999, 
there was extensive recruitment and the A. ammophila population 
increased approximately 87 percent (NPS 1999a, p. 1; Correy 2009, pp. 
6, Table 1). Notably, 1996 and 1997 had high precipitation, with 
resultant high lake levels (NPS 1999a, p. 2). The 1998-1999 surveys 
recorded approximately 20 percent of the population to be seedlings or 
recruit size class (NPS 1999a, Appendix A). The 2009 population 
estimate of the North Shore populations shows a decrease from the 1998-
1999 survey (Correy 2009, Table 1). However, the 1998-1999 survey was 
an exact count, whereas the 2009 was an estimate. Additionally, the 
subsequent 2010 population estimate shows a slight increase in the 
population size compared to the 2009 population estimate (Whipple 
2010e, pers. comm.). Hypotheses for population fluctuations are 
changing thermal activity of the underlying area, ground subsidence, 
changing precipitation levels, and human and animal activity (Correy 
2009, pp. 5-6). The A. ammophila population seems to be stable within 
the parameters of a population that lives in an unstable habitat that 
fluctuates with wave action and weather (Whipple 2010a, pers. comm.).

Five Factor Evaluation for Abronia ammophila

    Information pertaining to Abronia ammophila 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

    Potential factors that may affect the habitat or range of Abronia 
ammophila are discussed in this section, including: (1) Development, 
(2) trampling, (3) nonnative invasive plants, (4) climate change, and 
(5) drought.
Development
    Abronia ammophila occurs entirely inside YNP, which limits 
potential threats to its habitat. By statute, regulation, and policy, 
YNP conserves wildlife and habitat; preserves and maintains biological 
processes, ecosystem components, and ecological integrity; controls 
invasive plants; and protects and monitors populations of sensitive 
plants and animals (See Yellowstone National Park under Factor D. The 
Inadequacy of Existing Regulatory Mechanisms in this Five Factor 
Evaluation for Abronia ammophila section). YNP was established prior to 
the States in which it is located (Mazzu 2010, pers. comm.; Whipple 
2010e, pers. comm.). This means that YNP owns not only the land, but 
also the mineral rights; therefore, energy development is not a threat 
(Mazzu 2010, pers. comm.; Whipple 2010e, pers. comm.). Construction of 
new roads, trails, or structures within YNP is rare, with 
reconstruction of existing features occurring occasionally. When new 
construction or reconstruction occurs in areas where there are 
sensitive species, YNP analyzes and carries out construction in a 
manner that minimizes adverse effects. A. ammophila populations are 
located a sufficient distance from roads; therefore, road 
reconstruction does not impact any of the A. ammophila populations 
(Whipple 2010e, pers. comm.).
    As noted above (see Distribution and Abundance), Abronia ammophila 
has been extirpated in some areas in which there is no longer habitat 
due to the construction of roads or structures. However, the 
construction in these areas occurred prior to YNP identifying A. 
ammophila as a species of conservation concern. Now, when new 
construction or reconstruction occurs, YNP analyzes and carries out 
construction in a manner that avoids adverse effects to sensitive 
species. Additionally, projects must be accompanied by a Resource 
Compliance Checklist that requires the evaluation of any potential 
impacts to resources including rare plants; if there are impacts, 
mitigation measures are developed (Schneider 2010, pers. comm.). The 
majority of YNP remains undeveloped, and we have no information that 
this will change; therefore, we do not consider development to be a 
threat to the species now or in the foreseeable future.
Trampling
    Trampling of Abronia ammophila, by both humans and wildlife, is a 
potential concern at most sites (Whipple 2010a, pers. comm.). The 
Abronia genus is vulnerable to disturbance by trampling (NPS 1999b, p. 
8; Whipple 2010e, pers. comm.). Trampling is frequently indicated as a 
threat to A. ammophila (e.g., NPS 1999a; 1999b); however, studies that 
seek to document trampling indicate that there is very little foot 
traffic actually impacting the populations of A. ammophila (NPS 1999a, 
pp. 2, 5).

[[Page 33930]]

    The North Shore population is located in one of the least visited 
portions of the north side of Yellowstone Lake's shoreline (NPS 1999b, 
p. 8). A large wetland restricts access to this site from the west (NPS 
1999b, p. 8). The Storm Point Trail approaches the east end of the 
North Shore population, and visitors occasionally walk down the beach 
toward this population (NPS 1999b, p. 8). The YNP plans to install a 
sign just past the Storm Point Trail requesting that visitors remain 
near the water and avoid sensitive vegetation areas (Schneider 2010, 
pers. comm.).
    The Pelican Creek Nature Trail is also near the North Shore 
population (Schneider 2010, pers. comm.). No plants currently occur in 
this area; however, it is historical habitat (Whipple 2010a, pers. 
comm.; Schneider 2010, pers. comm.). YNP is currently considering 
conservation measures, including closing all or part of this trail to 
protect the potential habitat (Whipple 2010a, pers. comm.; Schneider 
2010, pers. comm.). A final decision, on this trail, has not been made 
at this time (Whipple 2011, pers. comm.).
    The Pumice Point population of Abronia ammophila is located near an 
unmarked picnic area; the plants are located within 10 m (32.8 ft) of 
the picnic tables (NPS 1999b, p. 8). This area is currently unsigned 
(not marked as a picnic area from the main road), and the entrance is 
inconspicuous (Whipple 2010c, pers. comm.). Additionally, the A. 
ammophila in this area may be benefiting from the disturbance; if foot 
traffic did not occur, the area might be more densely vegetated and not 
available as habitat for A. ammophila (NPS 1999b, p. 8; Whipple 2010c, 
pers. comm.).
    The two remaining populations are in areas with little visitation 
(NPS 1999b, p. 8). The Rock Point population is approximately a half-
hour walk from the closest access point (Whipple 2010c, pers. comm.). 
The South Arm population is accessible by boat, with a backcountry 
campsite located about 200 m (656.2 ft) from the population (Whipple 
2010c, pers. comm.). This backcountry campsite has no trail access 
(Whipple 2010c, pers. comm.).
    YNP has received approximately 3 million visitors a year for the 
past 20 years; visitation was over 3 million for 11 of those years (NPS 
2010a, unpaginated). From January to September of 2010, YNP received 
3.4 million visitors, an increase of 8.7 percent over the previous year 
(NPS 2010b, unpaginated). Even with increases to visitation, we have no 
information indicating that the number of visitors correlates with 
increased trampling of Abronia ammophila populations to a level that 
poses a threat to the species.
    Wildlife trampling, particularly by ungulates, is occasionally 
indicated as a concern (Whipple 2010a, pers. comm.) We believe that 
these anecdotal observations do not add up to routine impacts on a 
scale that would cause the species to be threatened or endangered. 
Additionally, we believe that trampling by wildlife represents a 
natural ecological interaction in YNP that the species would have 
evolved with and poses no threat to long-term persistence.
    In summary, the populations of Abronia ammophila are located in 
areas of YNP that do not receive the bulk of visitor traffic. When 
surveys have attempted to document trampling by humans, observers had 
determined that the impact is minor. We have only anecdotal evidence of 
wildlife trampling. Therefore, we have no information indicating that 
trampling by either humans or wildlife is a threat to the species now 
or in the foreseeable future.
Nonnative Invasive Plants
    After habitat loss, the spread of nonnative invasive species is 
considered the second largest threat to imperiled plants in the United 
States (Wilcove et al. 1998, p. 608). Nonnative invasive plants alter 
ecosystem attributes including geomorphology, fire regime, hydrology, 
microclimate, nutrient cycling, and productivity (Dukes and Mooney 
2004, pp. 411-437). Nonnative invasive plants can detrimentally affect 
native plants through competitive exclusion, altered pollinator 
behaviors, niche displacement, hybridization, and changes in insect 
predation (D'Antonio and Vitousek 1992, pp. 74-75; DiTomaso 2000, p. 
257; Mooney and Cleland 2001, p. 5449; Levine et al. 2003, p. 776; 
Traveset and Richardson 2006, pp. 211-213).
    As of 2010, YNP has documented 218 nonnative plant species 
occurring within its boundaries (NPS 2010e, p. 1). Encroachment of 
invasive plants may potentially affect A. ammophila, as this species 
prefers open, sparsely vegetated sites and does not compete well in 
areas that are more densely vegetated.
    Currently, nonnative invasive plants have affected only a few sites 
occupied by Abronia ammophila (NPS 1999b, p. 8; Whipple 2010a, pers. 
comm.). The invasive grass Bromus tectorum (cheatgrass) has been noted 
in the vicinity of the North Shore population, and Cirsium arvense 
(Canada thistle) occurs near the Rock Point population (Whipple 2010a, 
pers. comm.). Additionally, some B. tectorum was documented around the 
Storm Point population (NPS 1999b, p. 8). To combat these occurrences, 
YNP has an exotic vegetation management plan in place that emphasizes 
prevention, education, early detection and eradication, control, and 
monitoring (Olliff et al. 2001, entire).
    In summary, nonnative invasive plants occur within YNP; however, 
the majority of these species do not impact the habitat of Abronia 
ammophila. A few nonnative invasive species have been documented near 
the habitat of A. ammophila. These species are being monitored and the 
National Park System (NPS) has mechanisms in place to help control 
these encroachments. We have no information indicating that nonnative 
invasive species are modifying the species habitat to the extent that 
it represents a threat to the species now or in the foreseeable future.
Climate Change
    The Intergovernmental Panel on Climate Change (IPCC) was 
established in 1988 by the World Meteorological Organization and the 
United Nations Environment Program in response to growing concerns 
about climate change and, in particular, the effects of global warming. 
The IPCC Fourth Assessment Report (IPCC 2007, entire) synthesized the 
projections of the Coupled Model Intercomparison Project (CMIP) Phase 
3, a coordinated large set of climate model runs performed at modeling 
centers worldwide using 22 global climate models (Ray et al. 2010, p. 
11). Based on these projections, the IPCC has concluded that the 
warming of the climate system is unequivocal, as evidenced from 
observations of increases in global average air and ocean temperatures, 
widespread melting of snow and ice, and rising global average sea level 
(IPCC 2007, pp. 6, 30; Karl et al. 2009, p. 17). Changes in the global 
climate system during the 21st century are likely to be larger than 
those observed during the 20th century (IPCC 2007, p. 19). Several 
scenarios are virtually certain or very likely to occur in the 21st 
century including: (1) Over most land, weather will be warmer, with 
fewer cold days and nights, and more frequent hot days and nights; (2) 
areas affected by drought will increase; and (3) the frequency of warm 
spells and heat waves over most land areas will likely increase (IPCC 
2007, pp. 13, 53).
    In some cases, climate change effects can be demonstrated and 
evaluated (e.g., McLaughlin et al. 2002, p. 6073). Where regional 
effects from global climate change have been demonstrated, we can

[[Page 33931]]

rely on that empirical evidence to predict future impacts, such as 
increased stream temperatures (see status review for Rio Grande 
cutthroat trout, 73 FR 27900; May 14, 2008) or loss of sea ice (see 
determination of threatened status for the polar bear, 73 FR 28212; May 
15, 2008), and treat these effects as a threat that can be analyzed. In 
instances for which a direct cause and effect relationship between 
global climate change and regional effects to a specific species has 
not been documented, we rely primarily on synthesis documents (e.g., 
IPCC 2007, entire; Independent Scientific Advisory Board 2007, entire; 
Karl et al. 2009, entire) to inform our evaluation of the extent that 
regional impacts due to climate change may affect our species. These 
synthesis documents present the consensus view of climate change 
experts from around the world. Additionally, we have examined models 
downscaled to specific regions (e.g., Ray et al. 2010, entire; WRCC 
2011, p. 1; CIG 2011, p. 1)--including some in-progress finer-scaled 
models that include Wyoming and the surrounding area--in order to 
inform our evaluation of the extent that regional impacts may threaten 
species. Typically, the projections of downscaled models agree with the 
projections of the global climate models (Ray et al. 2010, p. 25). 
Climate change projections are based on models with assumptions and are 
not absolute.
    Portions of the global climate change models can be used to predict 
changes at the regional-landscape scale; however, this approach 
contains higher levels of uncertainty than using global models to 
examine changes on a larger scale. The uncertainty arises due to 
various factors related to difficulty in applying data to a smaller 
scale, and to the paucity of information in these models such as 
regional weather patterns, local physiographic conditions, life stages 
of individual species, generation time of species, and species 
reactions to changing carbon dioxide levels. Additionally, global 
climate models do not incorporate a variety of plant-related factors 
that could be informative in determining how climate change could 
affect plant species (e.g., effect of elevated carbon dioxide on plant 
water-use efficiency, the physiological effect to the species of 
exceeding the assumed (modeled) bioclimatic limit, the life stage at 
which the limit affects the species (seedling versus adult), the life 
span of the species, and the movement of other organisms into the 
species' range) (Shafer et al. 2001, p. 207). Moreover, empirical 
studies are needed on what determines the distributions of species and 
species assemblages.
    Regional landscapes also can be examined by downscaling global 
climate models. Two common methods of downscaling are statistical 
downscaling and dynamic downscaling (Fowler et al. 2007, p. 1548). 
These downscaled models typically inherit the broad-scale results of 
global climate change models, imbed additional information, and run the 
models at a finer scale (Ray et al. 2010, p. 25, Hostetler 2011, pers. 
comm.). These methods provide additional information at a finer spatial 
scale (i.e., all of Wyoming downscaled to a 15-km (9.3-mi) resolution 
(Hostetler 2010, pers. comm.). However, they are not able to account 
for the myriad of processes that may affect a species that only 
inhabits a narrow range, as local effects may reduce or amplify the 
large-scale patterns that are projected over the larger spatial 
resolution of the global climate models (Ray et al. 2010, p. 24). In 
summary, global climate models can play an important role in 
characterizing the types of changes that may occur, so that the 
potential impacts on natural systems can be assessed (Shafer et al. 
2001, p. 213). However, they are of limited use to assess local impacts 
to species with a limited range, such as the five plants discussed in 
this finding.
    Climate change is likely to affect the habitat of Abronia 
ammophila, but we lack scientific information on what those changes may 
ultimately mean for the status of the species. Yellowstone Lake water 
levels affect habitat conditions for A. ammophila. As noted previously, 
the record high lake levels of 1996 and 1997 (due to increased snowpack 
and subsequent spring snowmelt) had both positive and negative effects 
on A. ammophila (NPS 1999b, p. 7; Whipple 2002, p. 265). In general, 
the outflow and maximum water surface elevation of Yellowstone Lake are 
functions of winter snow accumulation and spring precipitation inputs; 
these vary significantly from year to year (Farnes 2002, p. 73). 
Analysis of snow depth and last date of snow cover in YNP from 1948 to 
2003 has shown that winters are getting shorter, as measured by the 
number of days with snow on the ground (Wilmers and Getz 2005, entire). 
This change is due to decreased snowfall and an increase in the number 
of days with temperatures above freezing (Wilmers and Getz 2005, 
entire).
    Climate change effects are not limited to the timing and amount of 
precipitation; other factors potentially influenced by climate change 
may in turn affect the habitat conditions for Abronia ammophila. For 
example, fire frequency, insect populations (e.g., mountain pine 
beetle, Dendroctonus ponderosae), and forest pathogens may be 
influenced by climate change (Logan and Powell 2001, p. 170; Westerling 
et al. 2006, pp. 942-943) and may in turn affect forest canopy cover 
and the timing of snowmelt within the Yellowstone Lake watershed. The 
increased rate of snowmelt caused by fire-generated openings in the 
forest canopy from the 1988 fires in YNP may have slightly reduced the 
annual maximum Yellowstone Lake level because it spread the snowpack 
melt rate over a longer period of time (Farnes 2002, p. 73). Impacts of 
specific events on A. ammophila and its habitat have not been analyzed.
    Climate change is likely to affect multiple variables that may 
influence the availability of habitat for A. ammophila. As lake levels 
have fluctuated in the past and A. ammophila has adapted to these 
fluctuations, this species should be able to persist so long as climate 
change does not result in extreme changes to important characteristics 
of the species habitat, such as the complete loss of water from 
Yellowstone Lake. At this time, the best available scientific 
information does not indicate that impacts from climate change are 
likely to threaten the species now or in the foreseeable future.
Drought
    Precipitation studies show that YNP weather cycles typically follow 
the larger weather patterns across the larger Northern Rockies 
ecosystem (Gray et al. 2007, p. 24). The reconstruction of 
precipitation levels in YNP from AD 1173-1998 shows strong interannual 
variability (Gray et al. 2007, entire). Moreover, extreme wet and dry 
years, which have occurred recently, fall within the range of past 
variability (Gray et al. 2007, entire).
    We believe that Abronia ammophila has evolved to adapt to recurring 
drought conditions because it persists in this type of environment. 
Short-term population fluctuations appear to be typical for the 
species. The population at Rock Point was thought to have been 
extirpated due to drought; however, a survey in 2004 located seedlings 
at this site (Saunders and Sipes 2004, p. 4). The Pumice Point 
population completely vanishes some years. It is located on sand that 
does not connect to the aquifer, and during drought years the 
population can be 9.1 m (30 ft) above water (Whipple 2010e, pers. 
comm.). Although drought may temporarily influence the abundance of

[[Page 33932]]

plants at some specific locations, we have no information indicating 
that drought threatens the species now or in the foreseeable future.
Summary of Factor A
    YNP offers protection of Abronia ammophila populations from all 
kinds of development including roads, campgrounds, buildings, mining, 
and energy development. There are currently no plans for any further 
development in YNP near the existing populations or potential habitat 
of A. ammophila. We have no information to suggest that trampling, 
nonnative invasive plants, climate change, or drought represents a 
threat to the species.
    We conclude that the best scientific and commercial information 
available indicates that Abronia ammophila is not in danger of 
extinction or likely to become so within the foreseeable future because 
of the present or threatened destruction, modification, or curtailment 
of its habitat or range.

Factor B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    There has been limited use and collection of Abronia ammophila and 
its parts for scientific study (Saunders and Sipes 2006, p. 77). 
Additionally, the Denver Botanical Gardens (DBG) collected 
approximately 3,300 A. ammophila seeds in 2005 (DBG 2008, p. 3). The 
DBG is a participating institution in the Center for Plant 
Conservation, an organization dedicated to preventing the extinction of 
plants native to the United States (Center for Plant Conservation 2010, 
unpaginated). Because these collections were limited, we do not believe 
this collection constituted a threat to the species. The collections 
also contribute to the long-term conservation of the species.
    Specimens, seeds, and parts of Abronia ammophila are occasionally 
collected for scientific purposes in order to increase the knowledge of 
this species (e.g., Saunders and Sipes 2006; DBG 2008); however, these 
collections are rare. We do not have any evidence of risks to A. 
ammophila from overutilization for commercial, recreational, 
scientific, or educational purposes, and we have no reason to believe 
this factor will become a threat to the species in the future. We 
conclude that the best scientific and commercial information available 
indicates that A. ammophila is not in danger of extinction or likely to 
become so within the foreseeable future because of overutilization for 
commercial, recreational, scientific, or educational purposes.

Factor C. Disease or Predation

Disease
    Abronia ammophila is not known to be affected or threatened by any 
disease. Therefore, we do not consider disease to be a threat to A. 
ammophila now or in the foreseeable future.
Predation--Grazing and Herbivory
    No studies have been conducted investigating the effects of grazing 
or herbivory on Abronia ammophila. Minimal insect herbivory has been 
noted. Sphingid moth larvae and others tentatively identified in the 
family Noctuidae have been seen feeding on the aboveground plant parts 
(Saunders and Sipes 2004, p. 11). Also, what appeared to be an army 
cutworm caterpillar was observed eating the belowground parts of an 
uprooted plant (NPS 1999b, p. 7).
    Additionally, some uprooted, partially eaten taproots were found in 
areas with abundant rodent tunnels (NPS 1999b, p. 7). Ungulate grazing 
has been noted on species that grow near Abronia ammophila; however, 
none has been noted on A. ammophila (NPS 1999b, p. 7). Any predation, 
as noted above, would represent a natural ecological interaction in 
YNP. We have no evidence that the extent of such predation represents a 
population level threat to A. ammophila. Therefore, we do not consider 
predation to be a threat to the species now or in the foreseeable 
future.
Summary of Factor C
    We have no evidence of adverse impacts to Abronia ammophila from 
disease or predation. We conclude that the best scientific and 
commercial information available indicates that A. ammophila is not in 
danger of extinction or likely to become so within the foreseeable 
future because of