[Federal Register Volume 76, Number 196 (Tuesday, October 11, 2011)]
[Proposed Rules]
[Pages 62722-62740]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-25470]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2011-0081; MO92210-0-0008]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition To List Amoreuxia gonzalezii, Astragalus hypoxylus, and 
Erigeron piscaticus as Endangered or Threatened

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 Amoreuxia gonzalezii (Santa Rita 
yellowshow), Astragalus hypoxylus (Huachuca milk-vetch), and Erigeron 
piscaticus (Fish Creek fleabane) as endangered or threatened with 
critical habitat under the Endangered Species Act of 1973, as amended 
(Act). After review of the best scientific and commercial information 
available, we find that listing Amoreuxia gonzalezii, Astragalus 
hypoxylus, and Erigeron piscaticus 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 Amoreuxia gonzalezii, 
Astragalus hypoxylus, and Erigeron piscaticus or their habitats at any 
time.

DATES: The finding announced in this document was made on October 11, 
2011.

ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R2-ES-2011-0081. Supporting 
documentation we used in preparing this finding is available for public 
inspection, by appointment, during normal business hours by contacting 
the U.S. Fish and Wildlife Service, Arizona Ecological Services Field 
Office, 2321 W. Royal Palm Road, Suite 103, Phoenix, AZ 85021; 
telephone (602) 242-0210; facsimile (602) 242-2513. If you use a 
telecommunications device for the deaf (TDD), please call the Federal 
Information Relay Service (FIRS) at (800) 877-8339. Please submit any 
new information, comments, or questions concerning this finding to the 
above street address.

FOR FURTHER INFORMATION CONTACT: Steve Spangle, Field Supervisor, U.S. 
Fish and Wildlife Service, Arizona Ecological Services Field Office, 
2321 W. Royal Palm Road, Suite 103, Phoenix, AZ 85021; telephone (602) 
242-0210; facsimile (602) 242-2513. 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 Threatened and 
Endangered Wildlife and Plants that contain substantial scientific or 
commercial information indicating that listing a 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: (a) Not warranted, (b) warranted, or (c) warranted, but 
immediate proposal of a regulation implementing the petitioned action 
is precluded by other pending proposals to determine whether species 
are endangered or threatened, and expeditious progress is being made to 
add or remove qualified species from the Lists of Endangered and 
Threatened Wildlife and Plants. Section 4(b)(3)(C) of the Act requires 
that we treat a petition for which the requested action is found to be 
warranted but precluded as though resubmitted on the date of such 
finding, that is, requiring a subsequent finding to be made within 12 
months. We must publish these 12-month findings in the Federal 
Register.

Previous Federal Actions

    Amoreuxia gonzalezii, Astragalus hypoxylus, and Erigeron piscaticus 
were formerly Category 2 candidate species, which are taxa for which 
information in our possession indicated that proposing to list was 
possibly appropriate, but for which persuasive data on biological

[[Page 62723]]

vulnerability and threats were not available to support a proposed 
listing rule (58 FR 51144; September 30, 1993). The designation of 
Category 2 candidate species was discontinued in 1996; therefore, these 
species are not currently considered candidates.
    On June 25, 2007, we received a formal petition dated June 18, 
2007, from Forest Guardians (now WildEarth Guardians), requesting that 
we do the following: (1) Consider for listing all full species in our 
Southwest Region ranked as G1 or G1G2 by the organization NatureServe, 
except those that are currently listed, proposed for listing, or 
candidates; and (2) list each species under the Act as either 
endangered or threatened and designate critical habitat. The 
petitioners presented two tables that collectively listed 475 species 
for consideration and requested that the Service incorporate all 
analyses, references, and documentation provided by NatureServe in its 
online database http://www.natureserve.org/ into the petition. The 
petition clearly identified itself as a petition and included the 
appropriate identification information, as required in 50 CFR 
424.14(a). We acknowledged the receipt of the petition in a letter to 
WildEarth Guardians dated July 11, 2007.
    On December 16, 2009, we made a 90-day finding (74 FR 66866) that 
the petition presented substantial scientific information indicating 
that listing 67 of the 475 species may be warranted; Amoreuxia 
gonzalezii, Astragalus hypoxylus, and Erigeron piscaticus were in that 
group of 67 species. For Amoreuxia gonzalezii, the petition listed 
urban and mining development and herbivory as threats to the species 
and its habitat, along with competition from nonnative species. For 
Astragalus hypoxylus, the petition listed degradation of habitat from 
livestock grazing and impacts from recreation, as well as indirect 
effects to bees, which may be the primary pollinator of this species. 
For Erigeron piscaticus, the petition listed recreational impacts, poor 
watershed conditions, flooding, and small population size as threats to 
the species and its habitat. The 90-day finding initiated a status 
review for these three plants (74 FR 66866; December 16, 2009). This 
notice constitutes the 12-month finding on the June 18, 2007, petition 
to list Amoreuxia gonzalezii, Astragalus hypoxylus, and Erigeron 
piscaticus as endangered or threatened.

Evaluation of the Status of Each of the Three Plant Species

    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.

Evaluation of the Status of Each of the Three Plant Species

    For each of the three species, we provide a description of the 
species and its life-history and habitat, an evaluation of threats for 
that species, and our finding that the petitioned action is warranted 
or not for that species.

Species Information for Amoreuxia gonzalezii

 Species Description

    Amoreuxia gonzalezii is an herbaceous perennial (plant living 3 or 
more years) in the Bixaceae family (Lipstick tree). The plant has a 
thickened starchy to woody rootstock, erect stems to 50 centimeters 
(cm) (20 inches (in)) in height, and long-petioled (long-stalked) 
leaves that are deeply parted into five to seven spathulate (spoon-
shaped) lobes (Poppendieck 1981, p. 24). The inflorescences (clusters 
of flowers) are few-flowered terminal cymes (branched flower clusters) 
with salmon- to yellow-colored flowers with maroon marks at the base of 
the upper and lower petals (Hodgson 1994, p. 3). The densely silky hair 
of the ovary is one of two main characteristics that separate this 
species from its more common relative A. palmatifida (Hodgson 1994, p. 
4). The second characteristic separating the two species is the mature 
fruit. The capsule in A. gonzalezii is ellipsoid and the seeds 
spherical; in A. palmatifida, the capsules are ovoid with reniform 
(kidney-shaped) seeds (Hodgson 1993, p. 27). Recent molecular work by 
Fulton (2011, pers. comm.) verifies that A. gonzalezii is a valid 
taxon, and we consider the species a listable entity.

Habitat and Biology

    Amoreuxia gonzalezii is the farthest north-occurring species within 
this tropical and sub-tropical genus found primarily in South America 
(the primary center of diversification), Central America, and Mexico 
(Poppendieck 1981, p. 24). Northern Mexico is the secondary center of 
diversification for the genus and contains the majority of documented 
locations of A. gonzalezii (Hodgson 1994, p. 5). In Mexico, A. 
gonzalezii is found in tropical areas in foothills thornscrub and 
tropical deciduous forest. Rainfall amounts range from 28 cm per year 
(11 in) near the coast (thornscrub) to 60 cm (24 in) in tropical 
deciduous forest. Freezes are very uncommon, and the bulk of rainfall 
occurs from July through mid-September. The plants in these vegetation 
communities are rainfall sensitive; in other words, the shrubs and 
trees leaf out only when the rains begin, and drop their leaves when 
the rainy season ends, usually in October (Yetman and Van Devender 
2002, pp. 9-12). Geology of collection sites varies from granitic, to 
quartz, to shale with quartz nodules and intrusives (molten igneous 
rock that is forced into cracks or between other layers of rocks). In 
the state of Sonora in Mexico, A. gonzalezii has been collected from 
the vicinity of [Aacute]lamos, Choquincahui, El Oasis, Guirocoba, 
Magdalena, Moctezuma, Onavas, Santa Ana, T[oacute]nichi, and Yocogigua, 
as well as the Curea-Guadalupe Tayopa area. In the state of Sinaloa in 
Mexico, the plant was

[[Page 62724]]

described from near Choix in the north. The specimens were found on 
both shallow and steep hill slopes at elevations from 160 to775 meters 
(m) (525 to 2542 feet (ft)).
    In the United States, Amoreuxia gonzalezii has been collected from 
the Devil's Cashbox area in the Santa Rita Mountains and Thomas Canyon 
in the Baboquivari Mountains (Southwest Environmental Information 
Network 2011). Both locations are in southeastern Arizona. We believe 
that the Arizona locations represent the northernmost distribution of 
this species. The Santa Rita A. gonzalezii plants are on lands 
administered by the Coronado National Forest, Nogales Ranger District. 
The plants occur in the foothills at an elevation of 1,311 to 1,402 m 
(4,300 to 4,599 ft) on steep limestone slopes and ridgetops. The 
habitat is described as the transition zone between Upper Sonoran 
desertscrub and grassland (NatureServe 2010). The collection from the 
granitic Baboquivari Mountains was from the sandy bank of a small 
drainage on private land at 1,280 to 1,371 m (4,198 to 4,497 ft) 
elevation. This site was described as an oak woodland and grassland 
(Southwest Environmental Information Network 2011).
    Very little is known about the biology of this species. Amoreuxia 
gonzalezii has a drought avoidance adaptation and only produces stems, 
leaves, flowers, and fruits following monsoon rains; it remains dormant 
under the ground the remainder of the year (Coronado National Forest 
1991, p. 3). Flowering occurs from July through September; flowers 
remain open only in the morning hours, closing by 11:00 a.m. (Hodgson 
1994, p.7). The species is an obligate outcrosser (needs pollen from 
another individual to successfully produce seed) and may be pollinated 
by unknown species of bees (Hodgson 1994, p. 7). Fruits develop in late 
July and August, maturing in September to mid-October (Hodgson 1994, p. 
7). Both flower and fruit production is dependent on the quantity of 
summer precipitation. Amoreuxia gonzalezii also reproduces vegetatively 
(asexually) from thick, tuberous or woody roots (Hodgson 2001, p. 94).
    In 1987 and 1988, staff from the Desert Botanical Garden (Garden) 
collected 142 seeds from the Devil's Cashbox area as part of the Center 
for Plant Conservation National Collection program for conserving rare 
plants and their seeds. The Garden's purpose was to determine viability 
of stored seed and increase the number of plants in their living 
collection (Desert Botanical Garden 1991, p. 1). An additional 72 seeds 
were collected by Garden staff from one population in Sonora, Mexico at 
an unknown date prior to 1991. In greenhouse trials, the Garden had 
variable low rates of success, from 0 to 43 percent, in germinating 4-
year-old seed stored both at room temperature and in a freezer 
facility. Viability of the seed bank and germination success in the 
wild is unknown, though Hodgson did report finding 10 seedlings in 1991 
in the Devil's Cashbox area (Southwest Environmental Information 
Network 2011). In a greenhouse experiment, 4 plants produced 7 fruits 
with a total of 232 seeds (Hodgson 1994, p. 7). Assuming this may be 
optimum fruiting potential given ample water and greenhouse care, the 
small population sizes from known populations (4to 24 individuals) may 
produce few seeds in typical years. There are no monitoring plots or 
current research in any of the populations in Arizona and Mexico.

Abundance

    There are virtually no population estimates for any locations in 
Mexico, although Hodgson (1994, p. 7) reported that one population in 
Mexico in 1988 had ``well over two dozen'' individuals. The information 
is not much better for the Arizona populations. Population estimates 
for the Santa Rita population ranged from 14 individuals in 1988 
(Southwest Environmental Information Network, 2011), to 4 individuals 
in 1989 (Hodgson 1989, p. 2), and 25 individuals in 1991 (Southwest 
Environmental Information Network, 2011). Hodgson (1994, p. 7) reports 
fewer than 24 individuals from 2 micro-populations in the Santa Rita 
Mountains. There were an estimated six to eight individuals in the 
Thomas Canyon population (Toolin 2011, pers. comm.) in the 1990s. 
Thomas Canyon was surveyed in 2011 and 30 plants were found (M. Baker 
2011, pers. comm.).
    In summary, there is very little ecological information available 
regarding Amoreuxia gonzalezii. The species is found in Mexico, and the 
United States, where the Arizona locations seem to represent the 
northernmost locations for this species. The best available scientific 
information does not indicate that this species was more widespread or 
that known populations have been extirpated. Both populations in 
Arizona seem to support a few individuals that are widely scattered 
over appropriate habitat. The species' growth is tied to the summer 
rains (monsoon), and in the fall, the plants become dormant. It seems 
likely that this species is more abundant in Mexico, and may be more 
closely tied with the thornscrub and tropical deciduous forest plant 
communities, which are more humid, and where many plant species grow in 
response to summer rainfall.

Five-Factor Evaluation for Amoreuxia gonzalezii

    In making this finding, information pertaining to Amoreuxia 
gonzalezii 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 Amoreuxia 
gonzalezii are discussed in this section, including: (1) Nonnative, 
invasive species; (2) fire; (3) development; (4) mining; (5) watershed 
degradation; (6) drought; and (7) climate change.
Nonnative, Invasive Species
    Throughout the Sonoran Desert ecosystem, invasions of the 
introduced Pennisetum ciliare (buffelgrass), Bromus rubens (red brome), 
Eragrostis lehmanniana (Lehmann lovegrass), Schismus barbatus 
(Mediterranean grass), and Pennisetum setaceum (crimson fountaingrass) 
have altered nutrient regimes; species composition and structure; and 
fire frequency, duration, intensity, and magnitude (Brooks and Pyke 
2001, p. 5). Although most of these species were intentionally 
introduced as forage for livestock, erosion control, or as ornamentals, 
each is now considered invasive and a threat to this ecosystem. Species 
such as P. ciliare are expected to increase their range even with 
continued and predicted drought events (Ward et al. 2006, p. 724). It 
is generally thought that invasion by exotic annual grasses will 
continue unchecked in the Sonoran Desert ecosystem in the future, 
reducing native biodiversity through direct competition and alteration 
of nutrient and disturbance regimes (Franklin and Molina-Freaner 2010, 
p. 1671).
    Although exotic grasses are reported to threaten Amoreuxia 
gonzalezii (Hodgson 1989, p. 3), no exotic grasses were noted within 
the Devil's Cashbox habitat during field surveys in May 2011 (Service 
2011a, p. 1). We have reviewed the best available scientific 
information on exotic plants in or near populations of A. gonzalezii in 
Thomas Canyon and in Mexico. In order to verify the identification and 
location of plants, specimens are collected, pressed and placed on 
sheets that are stored in herbaria. The labels on herbarium sheets 
often note associated plant species that

[[Page 62725]]

are found in association with the collected specimen. There are no 
exotic species noted as associates on any of the 12 specimen herbarium 
sheets located at the Arizona State University, University of Arizona, 
or the Sonoran University Herbarium collections, nor were any exotics 
noted in the Devil's Cashbox and Sonora A. gonzalezii habitat 
descriptions in Hodgson 1994 (pp. 5-6). Therefore, the best available 
information does not provide evidence that nonnative invasive species 
are a threat to the continued existence of A. gonzalezii or are likely 
to become so.
Fire
    There has been no scientific study on the impacts of fire on 
Amoreuxia gonzalezii. This species is present aboveground in July 
through October, and is dormant the remainder of the year. Because 
fires in Arizona usually burn in the premonsoon season (May-June), it 
seems unlikely that fire would affect this species (Alford et al. 2005, 
p. 453). In addition, the plant has a large starchy root, which is 
protected underground. It is possible that the root would be protected 
from surface fire, allowing the plant to resprout after fire. In 
summary, given the limited available information about the effect of 
fire on A. gonzalezii, we have determined that fire is not a threat to 
the continued existence of A. gonzalezii, or is likely to become so.
Development
    The Santa Rita Amoreuxia gonzalezii population is located below the 
Smithsonian Fred Whipple Observatory, located on Mt. Hopkins. There is 
a visitor center for the observatory located at the base of Mt. 
Hopkins, and Hodgson (1989, p. 4) noted that during the construction of 
the visitor center, disturbance came very close to some A. gonzalezii 
plants on the Devil's Cashbox ridge, but none of the plants were harmed 
during construction. Hodgson (1994, p. 9) noted that communication is 
vital among researchers, land managers, and potential developers in 
regards to development near populations of A. gonzalezii. Available 
information does not indicate any other development planned for this 
area, and the area is fairly remote. In addition, the population is on 
National Forest land, where development is not likely to occur. There 
is also no information indicating any development near the Thomas 
canyon site, nor any development near Amoreuxia populations in Mexico. 
We have evaluated and determined, on the basis of the best available 
scientific and commercial data, that development is not a threat to the 
continued existence of A. gonzalezii, nor is it likely to become so.
Mining
    NatureServe (2010) reports mining as a threat to this species, 
perhaps due to the proximity of two active mining claims to the south 
of the Devil's Cashbox plants (Ahern 2011, pers. comm.). There are 
currently no known direct impacts of active or proposed mines on any 
known population of Amoreuxia gonzalezii in the United States; these 
impacts are unknown for populations in Mexico. Hodgson (2001, p. 93) 
notes that A. gonzalezii tubers were collected frequently by native 
peoples from ``a graphite mine site'' in Mexico, implying no negative 
impact on the plant from this particular mine. It is unknown if the 
mine was active or inactive at the times of harvesting. In summary, 
based upon our review of the best available information, we conclude 
that mining is not a threat to the continued existence of A. 
gonzalezii, nor is it likely to become so.
Watershed Degradation
    Improper livestock grazing can lead to habitat degradation and 
watershed degradation. Overgrazing removes the vegetative cover which 
can lead to erosion. The Santa Rita population is located within the 
Agua Caliente grazing allotment on the Nogales Ranger District. 
Degradation of habitat due to livestock grazing was noted as a threat 
by NatureServe (2010) to Amoreuxia gonzalezii, although this was not 
evident in a 2011 visit to the Devil's Cashbox area (Service 2011a, p. 
1). The area that was assessed during that visit had no signs of 
livestock trailing, or sign of livestock. The Forest Service reports 
that this allotment, comprised of one pasture, is permitted for a 110 
cow-calf operation (Lockwood 2011, pers. comm.). The grazing season is 
May to November, but only 40 cows are presently grazing due to drought 
conditions (Lockwood 2011, pers. comm.). The ridges where the plants 
are located are quite steep, and it is unlikely that cattle graze in 
these locations. The status of livestock grazing with regard to the 
Thomas Canyon population is unknown, and no information is available 
regarding livestock grazing near Amoreuxia populations in Mexico. After 
reviewing the best available scientific information, we have determined 
that watershed degradation as a result of livestock grazing is not a 
threat to the continued existence of this species, nor is it likely to 
become so.
Drought
    Amoreuxia gonzalezii is dependent upon monsoon rains both for 
growth and the production of flowers and fruits (Hodgson 1989, p. 3). 
Hodgson (2001, p. 94) states that, ``With little precipitation, few 
fruits are produced from very depauperate plants.'' The Thomas Canyon 
location experienced less than average monsoon precipitation in 27 of 
49 recorded years (July to August, period of record for average was 
1961-2010, Kit Peak Weather Station, WRCC 2011). Similarly, the Devil's 
Cashbox area has had less than average monsoon precipitation during 33 
of 63 recorded years (period of record for average was 1946-2010, 
Tumacacori National Historic Park (NHP) Weather Station, WRCC 2011). In 
both locations, monsoon patterns varied yearly, with periods of below-
average precipitation never exceeding 7 consecutive years (Tumacacori 
NHP 1998-2004), thus giving A. gonzalezii periods of recovery.
    The climate pattern in the vicinity of [Aacute]lamos at the 
southern end of the Amoreuxia gonzalezii range in Sonora is very 
similar to Arizona, with the [Aacute]lamos-El Veranito weather station 
reporting below-average monsoon precipitation in 14 of 28 recorded 
years (July to August, period of record for average was 1977-2009, 
Comisi[oacute]n Nacional del Agua (CNA), 2011). At the near center of 
A. gonzalezii's Sonora range, the Carbo Weather station reported below 
average monsoon precipitation in 30 of 50 recorded years, 10 of which 
were consecutive from 1960-1969 (July to August, period of record for 
average was 1960-2009, CNA, 2011).
    It is not known whether Amoreuxia gonzalezii is drought-tolerant, 
but the observation that plants are still present in sites that have 
experienced reduced summer precipitation leads us to conclude that the 
species is at least adapted to drought conditions. A. gonzalezii has 
fleshy underground tubers, which can store food and water, and that is 
an adaptation for dealing with drought. The best available information 
does not indicate that drought is a threat to the continued existence 
of A. gonzalezii, and the plant may have some adaptations for dealing 
with drought; therefore, we conclude that drought is not a threat to 
this species, or is likely to become so.
Climate Change
    ``Climate'' refers to an area's long-term average weather 
statistics (typically for at least 20- or 30-year periods), including 
the mean and variation of surface variables such as temperature,

[[Page 62726]]

precipitation, and wind; ``climate change'' refers to a change in the 
mean or variability of climate properties that persists for an extended 
period (typically decades or longer), whether due to natural processes 
or human activity (Intergovernmental Panel on Climate Change (IPCC) 
2007a, p. 78). Although changes in climate occur continuously over 
geological time, changes are now occurring at an accelerated rate. For 
example, at continental, regional and ocean basin scales, recent 
observed changes in long-term trends include: a substantial increase in 
precipitation in eastern parts of North American and South America, 
northern Europe, and northern and central Asia, and an increase in 
intense tropical cyclone activity in the North Atlantic since about 
1970 (IPCC 2007a, p. 30); and an increase in annual average temperature 
of more than 2 [deg]F (1.1[deg]C) across the U.S. since 1960 (Global 
Climate Change Impacts in the United States (GCCIUS) 2009, p. 27). 
Examples of observed changes in the physical environment include: an 
increase in global average sea level, and declines in mountain glaciers 
and average snow cover in both the northern and southern hemispheres 
(IPCC 2007a, p. 30); substantial and accelerating reductions in Arctic 
sea-ice (e.g., Comiso et al. 2008, p. 1), and a variety of changes in 
ecosystem processes, the distribution of species, and the timing of 
seasonal events (e.g., GCCIUS 2009, pp. 79-88).
    The IPCC used Atmosphere-Ocean General Circulation Models and 
various greenhouse gas emissions scenarios to make projections of 
climate change globally and for broad regions through the 21st century 
(Meehl et al. 2007, p. 753; Randall et al. 2007, pp. 596-599), and 
reported these projections using a framework for characterizing 
certainty (Solomon et al. 2007, pp. 22-23). Examples include: (1) It is 
virtually certain there will be warmer and more frequent hot days and 
nights over most of the earth's land areas; (2) it is very likely there 
will be increased frequency of warm spells and heat waves over most 
land areas, and the frequency of heavy precipitation events will 
increase over most areas; and (3) it is likely that increases will 
occur in the incidence of extreme high sea level (excludes tsunamis), 
intense tropical cyclone activity, and the area affected by droughts 
(IPCC 2007b, p. 8, Table SPM.2). More recent analyses using a different 
global model and comparing other emissions scenarios resulted in 
similar projections of global temperature change across the different 
approaches (Prinn et al. 2011, pp. 527, 529).
    All models (not just those involving climate change) have some 
uncertainty associated with projections due to assumptions used, data 
available, and features of the models; with regard to climate change 
this includes factors such as assumptions related to emissions 
scenarios, internal climate variability and differences among models. 
Despite this, however, under all global models and emissions scenarios, 
the overall projected trajectory of surface air temperature is one of 
increased warming compared to current conditions (Meehl et al. 2007, p. 
762; Prinn et al. 2011, p. 527). Climate models, emissions scenarios, 
and associated assumptions, data, and analytical techniques will 
continue to be refined, as will interpretations of projections, as more 
information becomes available. For instance, some changes in conditions 
are occurring more rapidly than initially projected, such as melting of 
Arctic sea ice (Comiso et al. 2008, p. 1; Polyak et al. 2010, p. 1797), 
and since 2000, the observed emissions of greenhouse gases, which are a 
key influence on climate change, have been occurring at the mid- to 
higher levels of the various emissions scenarios developed in the late 
1990s and used by the IPCC for making projections (e.g., Raupach et al. 
2007, Figure 1, p. 10289; Manning et al. 2010, Figure 1, p. 377; Pielke 
et al. 2008, entire). Also, the best scientific and commercial data 
available indicates that average global surface air temperature is 
increasing and several climate-related changes are occurring and will 
continue for many decades even if emissions are stabilized soon (e.g. 
Meehl et al. 2007, pp. 822-829; Church et al. 2010, pp. 411-412; 
Gillett et al. 2011, entire).
    Changes in climate can have a variety of direct and indirect 
impacts on species, and can exacerbate the effects of other threats. 
Rather than assessing ``climate change'' as a single threat in and of 
itself, we examine the potential consequences to species and their 
habitats that arise from changes in environmental conditions associated 
with various aspects of climate change. For example, climate-related 
changes to habitats, predator-prey relationships, disease and disease 
vectors, or conditions that exceed the physiological tolerances of a 
species, occurring individually or in combination, may affect the 
status of a species. Vulnerability to climate change impacts is a 
function of sensitivity to those changes, exposure to those changes, 
and adaptive capacity (IPCC 2007, p. 89; Glick et al 2011, pp. 19-22). 
As described above, in evaluating the status of a species, the Service 
uses the best scientific and commercial data available, and this 
includes consideration of direct and indirect effects of climate 
change. As is the case with all potential threats, if a species is 
currently affected or is expected to be affected by one or more 
climate-related impacts, this does not necessarily mean the species is 
an endangered or threatened species as defined under the Act. If a 
species is listed as endangered or threatened, this knowledge regarding 
its vulnerability to, and impacts from, climate-associated changes in 
environmental conditions can be used to help devise appropriate 
strategies for its recovery.
    While projections from global climate model simulations are 
informative and in some cases are the only or the best scientific 
information available, various downscaling methods are being used to 
provide higher-resolution projections that are more relevant to the 
spatial scales used to assess impacts to a given species (see Glick et 
al, 2011, pp. 58-61).
    Regional landscapes can be examined by analyzing climate models 
that operate at small spatial scales; however, this approach involves 
some uncertainty. The uncertainty arises due to various factors related 
to difficulty in applying climate modeling to a smaller scale or 
unknown information, including regional weather patterns, local 
physiographic conditions, and fine-scale weather factors. Also, climate 
models do not model biological responses, such as life stages of 
individual species, generation time of species, and species' reactions 
to changing carbon dioxide levels not being included in the models. 
Most 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 effects on species of 
exceeding the assumed (modeled) bioclimatic limit, the life stage at 
which the limit affects the species (seedling versus adult), the 
lifespan of the species, and the movement of other organisms into the 
species' range) (Shafer et al. 2001, p. 207).
    For southern Arizona, the most current downscaled climate 
projections are available with \1/8\ degree resolution (approximately 
12 km x 12 km) from the Coupled Model Intercomparision Project (Maurer 
et al. 2007, entire). A West-Wide Climate Risk Assessment (Bureau of 
Reclamation 2011) has been completed, but the focus of this study

[[Page 62727]]

was downscaled surface water projections for major river systems in the 
West. As such, it is less useful for predicting upland effects from 
future climate change scenarios, although stream flow is highly 
correlated with precipitation and temperature, which also affect upland 
ecosystems. Downscaled climate projections represent a consensus of 
multiple climate models, but climate models alone are not able to 
account for the myriad of biological 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 and regional climate models can play an 
important role in characterizing general changes to climate, which is a 
major determinant of species distributions, so that the potential 
impacts on natural systems can be assessed (Shafer et al. 2001, p. 
213). However, they are less able to assess local impacts to species 
with a limited range, such as the three plants discussed in this 
finding.
    Climate change is likely to affect the long-term survival and 
distribution of native species, such as Amoreuxia gonzalezii, through 
changes in temperature and precipitation. Hot extremes, heat waves, and 
heavy precipitation will increase in frequency, with the Southwest 
experiencing the greatest temperature increase in the continental 
United States (Karl et al. 2009, pp. 28, 129). In the southwestern 
United States, average temperatures increased approximately 1.5 [deg]F 
(0.8 [deg]C) compared to a 1960 to 1979 baseline (Karl et al. 2009, p. 
129). By the end of this century, temperatures are expected to warm a 
total of 4 to 10 [deg]F (2 to 5 [deg]C) in the Southwest (Karl et al. 
2009, p. 129).
    Annual mean precipitation levels are expected to decrease in 
western North America and especially the southwestern States by 
midcentury (IPCC 2007, p. 8; Seager et al. 2007, p. 1181). The levels 
of aridity of recent drought conditions and perhaps those of the 1950s 
drought years will become the new climatology for the southwestern 
United States (Seager et al. 2007, p. 1181). As mentioned previously, 
southern Arizona is currently experiencing drought conditions, and 
there has been a decline in winter precipitation over the last 34 
years.
    Atmospheric levels of carbon dioxide are expected to double before 
the end of the 21st century, which may increase the dominance of 
invasive grasses leading to increased fire frequency and severity 
across western North America (Brooks and Pyke 2002, p. 3; IPCC 2002, p. 
32; Walther et al. 2002, p. 391). Elevated levels of carbon dioxide 
lead to increased invasive annual plant biomass, invasive seed 
production, and pest outbreaks (Smith et al. 2000, pp. 80-81; IPCC 
2002, pp. 18, 32; Ziska et al. 2005, p. 1328) and will put additional 
stressors on rare plants already suffering from the effects of elevated 
temperatures and drought.
    In summary, climate change is affecting and will affect temperature 
and precipitation events in the future. We expect that Amoreuxia 
gonzalezii may be negatively affected by climate change with respect to 
drought or alteration in summer precipitation. However, we believe that 
A. gonzalezii is adapted to arid conditions, and the species has 
survived previous periods of low summer rainfall in Arizona. Although 
we believe climate change will impact plants in the future, the best 
available information does not allow us to determine the magnitude and 
scope of the potential effects on a local scale to A. gonzalezii, and 
therefore, we conclude that climate change is not a threat to the 
continued existence of this species, nor is it likely to become so.
Summary of Factor A
    In conclusion, based on our review of the best available scientific 
and commercial information, we have determined that nonnative invasive 
species, fire, development, mining, and watershed degradation are not 
threats to Amoreuxia gonzalezii. Nonnative invasive species are not 
present in or near A. gonzalezii populations; therefore, they are not a 
threat to the species. The best available information does not indicate 
that fire, development, mining, or watershed degradation are threats to 
the species. Drought may influence the population structure of A. 
gonzalezii, but we conclude that drought is not a threat to the species 
because the species has some adaptations for living in arid 
environments and has survived periods of reduced summer precipitation. 
We acknowledge that climate change, particularly the predictions of 
less frequent, but perhaps more intense, summer precipitation, and 
increasing temperatures in the Southwest, will affect individuals 
populations of A. gonzalezii. However, the species is adapted to arid 
conditions, and therefore we have determined that climate change is not 
a threat to A. gonzalezii. Thus, the present or threatened destruction, 
modification, or curtailment of its habitat or range is not a threat to 
A. gonzalezii.

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

    Hodgson (2001, p. 91) notes that roots, young leaves, fruits, and 
seeds of Amoreuxia gonzalezii are edible. She says that, historically, 
the plant had been collected in great amounts and was ``once an 
important food source to various southwestern people.'' For example, 
the Onavas Pimas Tribe historically harvested this species frequently, 
although more recently, harvest is only incidental (Hodgson 2001, p. 
92). The tubers are collected and roasted by the Seri Indians on 
Tiburon Island, and by residents of Baja California. Evidently, the 
tubers of this species can be broken up and new plants will grow from 
the tuber pieces. In 1959, the noted anthropologist Homer Aschmann 
(Hodgson 2001, p. 94) observed with the similar and sympatric species 
Amoreuxia palmatifida that ``when the larger aboriginal population 
[native peoples of Mexico] exploited more regularly the flats where 
they grow, a larger yield of roots may have been maintained,'' implying 
that local peoples who relied on Amoreuxia for food may have enhanced 
populations by disturbing the soil and cutting roots. He stated that 
areas that were visited more regularly looked as if they had been 
plowed; the more disturbance, the more A. palmatifida grew. Both A. 
palmatifida and A. gonzalezii were historically, and continue to be, 
used by native peoples in a similar fashion, although we are unaware of 
this type of harvesting in Arizona. In summary, A. gonzalezii plants 
and roots have been used historically in parts of Mexico. There is no 
information regarding the current use of this species in Mexico, or its 
use in Arizona. Therefore, based on our review of the best available 
information, we have determined that collection of the plants or the 
roots is not a threat to A. gonzalezii, or is likely to become so.
    Amoreuxia gonzalezii is not a plant of horticultural interest. 
There is no documentation of any instances where A. gonzalezii was 
collected from the wild other than as voucher specimens to document 
occurrences (http://ag.arizona.edu/herbarium) or seed collection for 
the purposes of conserving the species. Therefore, based on the best 
available information, we have determined that collection is not a 
threat to the continued existence of the species, or is likely to 
become so.

Factor C. Disease or Predation

    There is no information indicating that disease affects Amoreuxia

[[Page 62728]]

gonzalezii. However, A. gonzalezii is very palatable to cattle and 
other ungulates (Hodgson 2001, p. 94). While some of the known 
locations in Arizona occur on steep limestone cliffs largely precluding 
cattle herbivory, plants in other locations are more susceptible. 
Hodgson (1989, p. 2) noted finding Amoreuxia plants in the Devil's 
Cashbox area with inflorescences (flowers) eaten. She was unable to 
ascertain if these plants were A. gonzalezii, or the more common A. 
palmatifida because the plants had no fruit (Hodgson 1989, p. 2). She 
also noted 13 missing plants from the Devil's Cashbox area just weeks 
after a previous site visit in 1990 (Hodgson 1989, p. 7). It is unknown 
how susceptible populations in Mexico are to grazing pressure. During a 
1988 visit to a population of A. gonzalezii outside of Moctezuma, 
Sonora, Hodgson (1989, p. 2) noted that most plants had been browsed or 
grazed. Grazing precludes sexual reproduction and, if it occurs on a 
frequent basis, may lead to reduced seed production (Hodgson 1994, p. 
9). However, A. gonzalezii also reproduces asexually; hence, the 
populations are not totally dependent on seed production for 
reproduction (Hodgson 2001, p. 94). Our review of the best available 
information did not produce any evidence that the long-term viability 
of A. gonzalezii populations in Arizona and Mexico has been affected by 
grazing, and therefore, we conclude that grazing is not a threat to 
this species.
    It has been suggested that javelinas (hoofed mammals in the peccary 
family) dig up the roots of Amoreuxia gonzalezii and that this may 
constitute a threat to the species (NatureServe 2010). The Service 
(2011a, p. 1) saw no evidence of this during the 2011 site visit, and 
there is no information available on how often javelina dig up the 
plants, or on what the long-term effects are to the populations. In 
addition, if the plants respond to digging by producing more plants, 
javelinas rooting in the soil may promote asexual reproduction. 
Therefore, after review of the best available information, we conclude 
that javelina digging up the plants and eating the roots of A. 
gonzalezii is not a threat to the species.
    Based on the best available information, we have determined that 
disease and predation are not threats to the continued existence of 
Amoreuxia gonzalezii, nor are they likely to become so.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    Amoreuxia gonzalezii is not protected by Arizona Native Plant Law 
(Arizona Revised Statutes, Chapter 7 1993, entire). It does not appear 
under any of the law's four categories of protection, although 
previously it was given consideration to be included for protection 
within the ``Salvage Restricted Protected Native Plants'' (Hodgson 
1994, p. 9), a level of protection that Hodgson considered inadequate. 
It was, however, never placed on this list (Hodgson 2011, pers. comm.). 
This means that the populations that occur on private land in Arizona 
have no protections. However, regardless of any protection under the 
Arizona Native Plant Law, our five-factor analysis suggests that A. 
gonzalezii populations are not subject to negative impacts at such a 
level that would place the species at risk. Evidence of this can be 
found in the Thomas Canyon population, which is on private property, 
and remains intact, as evidenced by surveys completed this year. 
Although A. palmatifida and A. wrightii are on the list of protected 
animals and plants for Mexico, A. gonzalezii is not listed and 
therefore receives no management considerations within its Mexican 
range (SEMARNAT 2008). Even so, we have determined that populations in 
Mexico are not subject to negative impacts at a level that would place 
the species overall at risk.
    Amoreuxia gonzalezii is considered by the Forest Service to be a 
``sensitive species'' in the Coronado National Forest. A sensitive 
species is defined as one not yet warranting listing as endangered or 
threatened, but which is sufficiently rare that its future survival is 
of concern (Forest Service Manual (FSM) 2670). The management of 
sensitive species is described in FSM 2670, and the management 
objectives are to develop and implement management practices to ensure 
that species do not become endangered or threatened because of Forest 
Service actions; maintain viable populations of all native and desired 
nonnative wildlife, fish, and plant species in habitats distributed 
throughout their geographic range on National Forest System lands; and 
develop and implement management objectives for populations or habitat 
of sensitive species or both.
    In addition, the Forest Service has to consider the effects of 
their actions on the viability of sensitive species through the 
National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et. seq.) 
process. As defined by Forest Service policy, actions must not result 
in loss of species viability or create significant trends toward the 
need for Federal listing. A. gonzalezii receives these protective 
measures through NEPA on Coronado National Forest land.
    In summary, Amoreuxia gonzalezii populations in the Coronado 
National Forest are protected by their status as sensitive species. We 
believe that the requirement to consider the species' long-term 
viability in the NEPA planning process provides adequate protection for 
the populations of A. gonzalezii in the Coronado National Forest. Any 
one factor in our analysis may constitute a threat; however, it is the 
combined analysis of all the potential threats to the species that 
determine whether a species warrants listing as an endangered or 
threatened species under the Act. In this case, there is no indication 
of actions or potential threats to the species on private land or in 
Mexico that rise to a level such that listing is warranted. As such, we 
conclude that the best available information indicates that A. 
gonzalezii is not threatened by inadequate existing regulatory 
mechanisms.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

    Amoreuxia gonzalezii has been classified as the global rank of G1, 
Critically Imperiled, by NatureServe (2010) due to the small number of 
small populations globally, palatability to cattle, and threat of 
exotic annual grasses. Even though there are only 2 occurrences in the 
United States, there seem to be at least 12 occurrences in Mexico. 
There have been no systematic surveys in Mexico, and very few 
population estimates.
    Information on a species' rarity is relevant to the conservation 
status of a species. Generally speaking, a species that has a 
geographically restricted range is likely to be more susceptible to 
environmental threats (e.g., fire, flood, drought, human land use), 
should they occur, than a species that is not rare, because one fire or 
flood could affect a larger total percentage of the range of a rare 
species than of a widespread species. However, there is no available 
information in this case to evaluate whether any environmental threats 
are currently acting upon this potentially rare species in a negative 
way, or are reasonably likely to act on it in the future. The fact that 
a rare species is potentially vulnerable to stochastic processes does 
not necessarily mean that it is reasonably likely to experience, or 
have its status affected by, a given

[[Page 62729]]

stochastic process within timescales that are meaningful under the Act.
    A species that has always been rare, yet continues to survive, 
could be well-equipped to continue to exist into the future. Many 
naturally rare species have persisted for long periods within small 
geographic areas, and many naturally rare species exhibit traits that 
allow them to persist despite their small population sizes. 
Consequently, the fact that a species is rare does not necessarily 
indicate that it may be in danger of extinction in the foreseeable 
future.
    The best available information provides no evidence that effects 
often associated with small populations that were not naturally rare, 
such as inbreeding depression or genetic drift, may be occurring in A. 
gonzalezii populations. There is also no evidence that potential 
effects to the species or its habitat may be more significant than 
historically present such that a naturally rare species, such as A. 
gonzalezii, would be at risk. Therefore, we conclude that overall 
rarity and small population size are not a threat to A. gonzalezii, nor 
are they likely to become so.

 Finding for Amoreuxia gonzalezii

    As required by the Act, we evaluated the five factors in assessing 
whether Amoreuxia gonzalezii is endangered or threatened throughout all 
or a significant portion of its range. We examined the best scientific 
and commercial information available regarding the past, present, and 
future threats faced by A. gonzalezii. We reviewed the petition, 
information available in our files, other available published and 
unpublished information, and we consulted with recognized species 
experts.
    There are no obvious threats to Amoreuxia gonzalezii or its 
habitat. The species has been used historically as a food source by 
indigenous people, but we have no information that collection and use 
of the plants and tubers are currently a threat to the species or 
likely to become so. Long-term drought and reduced summer rainfall will 
likely affect individual plants and populations. However, the plants 
are tolerant of moderate disturbance, and the species is adapted to 
arid condition, as evidenced by the plants' survival during recent 
periods of reduced summer rainfall. Based on the limited information 
available, we conclude that drought is not threat to this species or 
likely to become so. Climate change will likely affect the status of A. 
gonzalezii in the future; however, the limited information available 
that can be applied at a local scale does not suggest that climate 
change is likely to threaten the species. Regarding other factors 
potentially affecting A. gonzalezii, including nonnative, invasive 
species; fire; development; mining; and watershed degradation, the best 
available scientific information provides no evidence indicating that 
they are currently threatening the species or likely to do so in the 
future. Similarly, there is no evidence that overutilization, disease, 
or predation are affecting this species. In addition, we have 
determined that small population size is also not a threat to the 
species because the species appears to be naturally rare and there are 
no potential threats acting on the species above historical levels. 
Further, because we have determined there are no threats on the 
species, and none likely, existing regulatory mechanisms are adequate.
    Based on our review of the best available scientific and commercial 
information pertaining to the five factors, we find that the potential 
threats are not of sufficient imminence, intensity, or magnitude to 
indicate that Amoreuxia gonzalezii is in danger of extinction 
(endangered) or likely to become endangered within the foreseeable 
future (threatened), throughout all of its range.

Significant Portion of the Range

    Having determined that Amoreuxia gonzalezii is not in danger of 
extinction, or likely to become so, throughout all of its range, we 
must next consider whether there are any significant portions of the 
range where A. gonzalezii is in danger of extinction or is likely to 
become endangered in the foreseeable future.
    The Act defines an endangered species as one ``in danger of 
extinction throughout all or a significant portion of its range,'' and 
a threatened species as one ``likely to become an endangered species 
within the foreseeable future throughout all or a significant portion 
of its range.'' The term ``significant portion of its range'' is not 
defined by the statute. For the purposes of this finding, a portion of 
a species' range is ``significant'' if it is part of the current range 
of the species, and it provides a crucial contribution to the 
representation, resiliency, or redundancy of the species. For the 
contribution to be crucial, it must be at a level such that, without 
that portion, the species would be in danger of extinction. We also 
considered the historical range of the species, and have determined 
that the current range is no different from the historical range. 
Therefore, there has been no loss of the historical range, and no 
further analysis of the historical range is required.
    In determining whether Amoreuxia gonzalezii is endangered or 
threatened in a significant portion of its range, we considered status 
first to determine if any threats or potential threats acting 
individually or collectively endanger or threaten the species in a 
portion of its current range. We evaluated the current range of A. 
gonzalezii to determine if there is any apparent geographic 
concentration of the primary stressors potentially affecting the 
species including nonnative, invasive plants; fire; development; 
mining; watershed degradation; and drought. We have analyzed the 
stressors to the degree possible, and determined that they are 
essentially uniform throughout the species' range. We also found the 
stressors are not of sufficient imminence, intensity, magnitude, or 
geographically concentrated such that it warrants evaluating whether a 
portion of the range is significant under the Act. We do not find that 
A. gonzalezii is in danger of extinction now, nor is likely to become 
endangered within the foreseeable future, throughout all or a 
significant portion of its range. Therefore, listing A. gonzalezii as 
an endangered or threatened species under the Act is not warranted at 
this time.
    We request that you submit any new information concerning the 
distribution and status of, or threats to, Amoreuxia gonzalezii to our 
U.S. Fish and Wildlife Service Office (see ADDRESSES section) whenever 
it becomes available. New information will help us monitor A. 
gonzalezii and encourage its conservation. If an emergency situation 
develops for A. gonzalezii, or any other species, we will act to 
provide immediate protection.

Species Information for Astragalus hypoxylus

Species Description

    Barneby (1964, pp. 1028-1029) and Warren et al. (1991, pp. 3-4) 
describe Astragalus hypoxylus as an herbaceous perennial, in the 
Fabaceae (Pea) family. The species forms a compact mat of stems that 
typically lay flat against the ground, although the outer ends of the 
stems may turn up. The mat can be up to 15 cm (6 in) in diameter. The 
species forms a tap root that is dense and fibrous. The alternate 
leaves are compound with 11 to 13 ovate leaflets that are each 2 to 4.5 
millimeters (mm) (0.1 to 0.2 in) long. The leaflets are bicolored; the 
undersides are gray with sparse tiny hairs; the tops of the leaflets 
are yellowish-green, smooth, and

[[Page 62730]]

hairless. The leaflets have a distinct fold along the midrib.
    The inflorescence is very compact and ball-shaped, approximately 1 
cm (0.4 in) in diameter and 1 to 1.5 cm (0.4 to 0.6 in) long and looks 
somewhat like clover flowers. The flowers are approximately 6 mm (0.2 
in) long with petals that are whitish, with light purple tips. The 
flower stalks are erect above the vegetative mat. Fruits are small, 
oval pods 7 to 9 mm (0.3 to 0.35 in) long and 2 to 2.5 mm (0.1 to 0.16 
in) diameter. The pods are yellowish at the base and purplish towards 
the tip when ripe. The pods do not split open, but drop whole from the 
plant (Warren et al. 1991, pp. 3-4).
    Astragalus hypoxylus most closely resembles A. parvus (no common 
name) and A. nothoxys (sheep milkvetch). Astragalus parvus is only 
known from Mexico, but A. nothoxys may be found with A. hypoxylus 
(Johnson et al. 1992, p. 3). There are field characteristics that 
differentiate the two species. A. nothoxys has much longer flowering 
stalks, and the inflorescence is spread out along the flowering stems, 
unlike the compact, clover-like flowers of A. hypoxylus. The seed pods 
of A. nothoxyus are longer, narrower, three-sided, and green when fully 
ripe, while those of A. hypoxylus are oval and yellowish-purple when 
ripe. There has never been any disagreement in the scientific 
literature regarding the taxonomy of this species; thus we consider A. 
hypoxylus to be a valid taxon and a listable entity.

Habitat and Biology

    Levin (1987, pp. 170-171) described the habitat that supports 
Astragalus hypoxylus as ``stony openings in pine-oak juniper woodland, 
restricted to limestone derived soils.'' Van Devender (1986, pers. 
comm.) noted the same type of habitat, on a south-to-southwest 
exposure. Warren et al. (1991, p. 7) observed that A. hypoxylus is 
found in open, rocky clearings in woodlands comprised of Quercus emoryi 
(Emory oak), Q. oblongifolia (Mexican blue oak), Juniperus deppeana 
(alligator juniper), and Pinus cembroides (Mexican pinyon). The ground 
is characterized by loosely consolidated, gravelly soil composed of 
limestone and weathered rock. The plants are found at an elevation of 
approximately 1,676 m (5,500 ft) (Warren et al. 1991, p. 7). This 
habitat type is referred to as oak-savannah and is relatively common in 
the mountains of southeastern Arizona between elevations of 1,370 to 
1,830 m (4,494 to 6,000 ft) (Brown 1982, p. 59).
    Astragalus hypoxylus produces flowers in the spring (April-May), 
with fruits maturing approximately 3 weeks after the onset of flowering 
(Johnson et al. 1992, p. 5). Pollination studies on different species 
of Astragalus (Karron 1988, p. 332; Sugden 1985, pp. 303-304; Green and 
Bohart 1975, pp. 383-384; Geer et al. 1995, p. 23) reported that 
several bee species in the genera Bombus, Osmia, and Anthophora were 
the primary pollinators. However, there have been no studies on the 
pollinators for A. hypoxylus.
    The pods of Astragalus hypoxylus do not split open when ripe and 
usually fall to the ground near the parent plant. However, the pods are 
light and may be blown to other locations by the wind (Johnson et al. 
1992, p. 6). Seedlings are often detected in open places away from the 
parent plants; however, nothing is known regarding seed dispersal of 
this species (Falk, 2011, pers. obs.).
    Germination studies of Astragalus hypoxylus were carried out by the 
Desert Botanical Garden (Garden) as part of the Center for Plant 
Conservation National Collection program for conserving rare plants and 
their germplasm. Seeds were collected from the Harshaw and Bear Canyon 
populations in 1991 and 1992. During the seed collection trips, the 
biologists noted that ``plants were frequent along disturbed areas 
(erosion cuts, dirt roads)'' (Pritchett-Kozak and Ecker 1992, p. 20). 
Two germination tests were done in 1992, with germination rates of 66 
and 76 percent (Pritchett-Kozak and Ecker 1992, p. 20). Tests done in 
1991 with fresh seed and previously frozen seed were used, and the 
germination rates were high for both sets of seeds, indicating that 
freezing does not interfere with seed viability. Germination took place 
during an average daytime temperature range of 73 to 86 [deg]F (23 to 
30 [deg]C) (Ecker 1991, p. 1). These warm daytime temperatures may 
indicate that the seeds germinate in the summer, in response to summer 
rainfall, rather than in the winter. Also, the seeds readily germinated 
in August, indicating that there is no summer dormancy for these seeds 
(Ecker 1991, p. 1). Currently, there are approximately 14,000 seeds in 
frozen storage at the Garden and the National Seed Storage Lab in Ft. 
Collins, Colorado (http://www.centerforplantconservation.org). These 
seeds are available for re-introduction efforts or augmentation of 
existing populations.
    In 1993, plants produced from collected seed were initiating floral 
buds in the greenhouse by February 20. These were plants that were 
produced from previous seedling experiments. On March 16, the plants 
were placed outside on the grounds of the Garden, underneath native 
trees. The plants began flowering profusely by early April. Open 
pollination (plants were left in the open and pollination occurred 
naturally) was successful, and the plants were producing numerous 
fruits by April 20. There was no indication of pollinators in the area. 
Plants that had been previously left in the greenhouse had not produced 
seed, probably due to a lack of pollinators in the greenhouse. 
Controlled cross-pollination of two plants (two flowers per plant) was 
conducted on April 13, which resulted in two fruits per plant 
(Pritchett-Kozak 1993, p. 20). Earlier attempts at self-pollination 
failed, but the technique (use of a small paintbrush to transfer the 
pollen) may not have been optimal (Pritchett-Kozak and Ecker 1992, p. 
21). The results of the open pollination and the controlled cross-
pollination experiment likely indicate that Astragalus hypoxylus is an 
obligate outcrosser (Pritchett-Kozak 1993, p. 20).
    In conclusion, there is not a great deal of information on the 
biology and ecology of this species. The pollinators of the species are 
unknown; it is surmised that the plants are obligate outcrossers, and 
that pollination takes place in the field because fruit and seeds are 
produced. It is not known how seed is dispersed. Based on the 
germination experiments conducted by the Desert Botanical Garden, the 
best available information suggests that plants germinate in response 
to summer rainfall. Also, there is some anecdotal information that 
these plants occupy disturbed areas and may be tolerant of moderate 
disturbance.

 Distribution, Abundance, and Trends

    Astragalus hypoxylus was first collected by J. G. Lemmon in 1882 in 
Cochise County, Arizona, at a location described as ``Mahoney's Ranch, 
near Ft. Huachuca.'' (Johnson et al. 1992, p. 4). This site description 
proved to be so vague that this area was never able to be located again 
(Johnson et al. 1992, p. 4). The species was not detected again until 
1986, when it was collected in the Patagonia Mountains, approximately 
4.5 kilometers (km) (2.8 miles (mi)) south of Harshaw on the road to 
Washington Camp, in the Coronado National Forest (Levin 1987, pp. 170-
171). Later in 1986, botanists visited this same location and counted 
approximately 107 plants in the area, again noting that the plants were 
``common in grassy openings in oak woodland on relatively steep slopes 
with coarse sandy soils'' (Van Devender 1986, pers. comm.; Kennedy 
1986, pers. comm.). In 1991, Malusa et al. (1992, p. 25) found two 
additional populations in the Patagonia

[[Page 62731]]

Mountains, near the Harshaw site. Approximately 180 plants were found 
in adjacent canyons. These populations are within a couple of miles of 
the Harshaw site and, for the purposes of this finding, will be 
referred to as the Harshaw2 populations.
    In addition, many surveys were undertaken by staff at the Nature 
Conservancy and other botanical contractors to the Coronado National 
Forest, and populations of Astragalus hypoxylus were found in the 
Huachuca Mountains in Scotia, Bear, and Sycamore canyons, and in 
Collins Canyon in the Canelo Hills (Warren et al. 1989, p 30; Gori et 
al. 1990, p. 36; Gori et al. 1991, p. 45; Fishbein and Warren 1994, pp. 
6-7). Populations in Bear, Sycamore, and Scotia canyons are dispersed 
over a wide area and composed of several sub-populations, but, for the 
purposes of this finding, will be referred to as individual 
populations. All of these locations are on the Sierra Vista Ranger 
District of the Coronado National Forest. In addition, suitable habitat 
on Ft. Huachuca and in Sonora, Mexico was searched, but plants were not 
found (Warren et al. 1991, pp. 5-6; Johnson et al. 1992, pp. 4-5; 
Warren and Reichenbacher 1991, p. 26; Fishbein and Warren 1994, pp. 6-
7; Malusa 1995, p. 1). Therefore, the current distribution encompasses 
only plants that occur along Harshaw Road in the Patagonia Mountains, 
in Bear, Scotia, and Sycamore canyons in the Huachuca Mountains, and in 
Collins Canyon in the Canelo Hills.
    The Nature Conservancy established monitoring plots for Astragalus 
hypoxylus in several of the populations (Warren et al. 1991, p. 8). Two 
plots were established to monitor growth, reproduction, and mortality 
of individual plants in the Harshaw population. These plots were 
established in 1988, but one plot was abandoned in 1989 because the 
site was steep and the survey was causing damage to the plants within 
the monitoring plot. The remaining plot was monitored annually, from 
1989-1991 and in 1993. Another plot was established at the Bear Creek 
population in 1989, and data were collected from this plot in the same 
years as the Harshaw plot. All plots were monitored in late April or 
May, when the plants flower and set fruit. Neither monitoring plot has 
been evaluated since 1993. However, some occupied sites were visited in 
1995, in 2010, and in 2011, and population estimates were made, 
although no other data were collected in the monitoring plots. Table 1 
presents population estimates for the known locations.

    Table 1--Population Counts and Estimates for Astragalus Hypoxylus
------------------------------------------------------------------------
                                         Estimated number of individuals
    Population  (year of discovery)                   (year)
------------------------------------------------------------------------
Harshaw (1986).........................  100-200 (1986)
** plants in both monitoring plots.....  109 (1988) **
* plants in remaining monitoring plot..  112 (1989) *
                                         70 (1990) *
                                         139 (1991) *
                                         114 (1993) *
                                         22 (2011)
Bear Canyon (1988).....................  110 (1989) *
* plants in the monitoring plot........  60 (1990) *
                                         85 (1991) *
                                         61 (1993) *
                                         154 (1995) *
                                         0 (2010) *
Bear Canyon (1990).....................  50 (1990)
(plants found outside the monitoring     346 (1995)
 plot and in other areas of Bear         100 (2010)
 Canyon).
Scotia Canyon (1990)...................  600-700 (1990)
                                         1058 (1995)
                                         500-600 (2010)
Harshaw2 (1991)........................  180 (1991)
                                         0 (2011)
Sycamore Canyon (1993).................  320 (1993)
                                         70-80 (1994) (not all sub-
                                          populations visited)
                                         65-80 (1994) (not all sub-
                                          populations visited)
                                         12 (1995) (not all sub-
                                          populations visited)
Canelo Hills (1993)....................  No estimate given in 1993;
                                          presence of ``small
                                          population'' was noted.
------------------------------------------------------------------------

    Based on the surveys and monitoring data, there have been some 
declines in the numbers of individuals found in the monitoring plots 
and in additional occupied locations. The Harshaw population appeared 
relatively stable throughout the monitoring period, with some 
fluctuations in the overall numbers. For the period 1991-1993, 
survivorship was 40 percent, with 64 recruits in 1993, which 
represented 56 percent of the population in the plot. It is unfortunate 
that the Harshaw site as not visited again until May 2011 (Service 
2011b, pp. 1-4). During this visit, 5 healthy plants, which had 
flowered, were found in the cutbank of the road, and 14 additional 
plants were found nearby, slightly north of the road. The area where 
the original Harshaw monitoring plot was thought to have been was 
searched thoroughly and only three plants were found. These plants were 
very small compared to those near and in the cutbank of the road. The 
entire site was described as very dry, and the native grasses 
``crunched beneath our feet'' (Service 2011b, p. 2). It is possible 
that the plants near the road were getting additional moisture due to 
their downslope location and their proximity to the road. Additional 
searches were conducted near the described locations for the Harshaw2 
populations, but no plants were found. Given the 18-year gap in 
monitoring or visiting this site, we are unable to determine the long-
term trend for this population.
    The situation is similar for the Bear Canyon monitoring plot. 
Overall numbers fluctuated, but as of 1995,

[[Page 62732]]

there were more plants in the plot than there had been when the plot 
was established. Fifteen years passed before the next visit, which 
occurred in October 2010 (Service 2010, p. 1). This is not the ideal 
time of year for a visit, but the plants are usually visible if there 
has been summer rainfall. In this case, based on the growth of the 
perennial grasses in the surrounding area, it seemed as if there had 
been summer precipitation (Falk 2011, pers. obs.). No plants were found 
in the monitoring plot, but there were plants to the east and south of 
the plot. The plants were widely scattered over the area. There was no 
evidence of flowering or fruits.
    Additional surveys were conducted that day (Service 2010, p. 1) 
along Forest Service Road 61, near Sycamore Canyon. Plants were 
scattered in several different locations adjacent to the road, 
including some areas that had been recently disturbed by vehicle 
traffic. The majority of the plants observed were healthy. Many of 
these plants looked like juveniles produced during the summer of 2010. 
The last site visited was Scotia Canyon (Service 2010, p. 1). Many 
plants were observed below the uppermost pond on the former Peterson 
ranch property (now part of the Coronado National Forest) and 
immediately downslope of that. Some of the largest plants were in the 
roadbed, associated with eroded portions of the road. The observations 
of these plants growing in disturbed areas (road cuts and eroded banks) 
may indicate that this species is adapted to and may tolerate moderate 
disturbance. We were unable to determine long-term trends for these 
populations based on inconsistent monitoring efforts.
    Another type of disturbance to the plant's habitat is fire. There 
is no information on the plant's adaptation to fire, but the habitat 
where the species grows is subject to fire on a periodic basis (Kaib et 
al. 1996, p. 261). The observation that Astragalus hypoxylus is 
tolerant of moderate disturbance may indicate that the species is fire 
adapted, and may need periodic fire to reduce competition from grasses 
and remove overstory vegetation that may increase understory 
competition and shading.
    Some of the fluctuation in population size may be attributable to 
variation in climate. During dry years, there was increased mortality 
of plants, and larger plants died in association with consecutive dry 
years (Johnson et al. 1992, p. 7). Recruitment and survival may also be 
correlated with winter precipitation as evidenced by the number of 
recruits that were counted in 1993 in the Bear Canyon plot; more than 
72 percent of the individuals counted that year were seedlings (Falk 
and Warren 1994, p. 36). Coincidentally, 1992 was an El Ni[ntilde]o 
year, with above-average precipitation for southern Arizona.
    There are some observations from the monitoring efforts that may 
shed light on the ecology of this species. Population size and flower 
production appear to fluctuate greatly from year to year. There seems 
to be a correlation with winter rainfall. That is, when winter 
precipitation is good, the plants are larger and they produce more 
flowers and fruit (Warren et al. 1991, p. 9; Johnson et al. 1992, pp. 
7-8). Astragalus hypoxylus has a taproot, and individual plants may be 
dormant (no above-ground biomass visible) during dry years, but produce 
growth again when there is rain (Falk 2011, pers. obs.). Consequently, 
the reduction in numbers across almost all of the populations may be in 
response to the on-going drought in southern Arizona. Winter rainfall 
has been declining steadily for the last 34 years, and most noticeably 
in the period from 1998 to the present (McPhee et al. 2004, p. 2). 
Although the correlation between population size and climate is not a 
formal test of this hypothesis, the sharp decline noted for most of 
these populations may be the result of prolonged drought.

Five-Factor Evaluation for Astragalus hypoxylus

    In making this finding, information pertaining to Astragalus 
hypoxylus 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 
Astragalus hypoxylus are discussed in this section, including: (1) 
Recreation; (2) watershed degradation resulting from improper livestock 
grazing; (3) nonnative invasive species; (4) fuel wood harvesting; (5) 
fire; (6) road maintenance; (7) drought; and (8) climate change.
Recreation
    All known populations of this species occur on the Sierra Vista 
Ranger District, on the Coronado National Forest. There is no special 
management for the populations on Forest Service lands. The populations 
at Harshaw do not appear to be affected by any recreational activities 
(Johnson et al. 1992, p. 12). There was no sign of recreational 
activity or impacts during the 2011 site visit (Service 2011b, entire). 
The same is true for the populations scattered along Forest Service 
Road 61, near Sycamore Canyon and in Scotia Canyon. In 2010, neither of 
these populations showed evidence of trampling or associated effects 
from recreational activities.
    The only population that has been identified as being impacted by 
recreational activity has been the upper Bear Canyon population. This 
population has been impacted by an informal parking lot near the 
turnoff to Wakefield Camp, which allows for access to Bear Creek, and 
is a very popular area for dispersed camping and hiking (Warren et al. 
1991, p. 10; Gori et al. 1991, p. 45). In 2000, the Forest Service 
blocked off the informal parking area, created a formal parking in a 
less sensitive area, and restricted access to the Bear Creek riparian 
area (Frederick 2011, pers. comm.). This site has not been evaluated to 
determine if these changes reduced the impacts from recreational 
activity on Astragalus hypoxylus. At any rate, this population is 
relatively small (50 plants were estimated at the time of discovery in 
1990) (Gori et al. 1991, p. 45) and represents less than 10 percent of 
the current population. In conclusion, recreational impacts may have 
affected only one of the sub-populations in the entire range of the 
species, and corrective actions were taken to reduce the impacts. 
Review of the best available scientific information revealed no further 
evidence that recreation is negatively affecting other A. hypoxylus 
populations; therefore, we determined that recreation is not a threat 
to the continued existence of the species, nor is it likely to become 
so.
Livestock Grazing
    All of the Astragalus hypoxylus populations occur with Forest 
Service grazing allotments. The Harshaw populations are within the 
Bender allotment, and all of the other populations are located within 
the Lone Mountain allotment. The following information is from the 
Service's biological opinion on the Continuation of Livestock Grazing 
on the Coronado National Forest (2-21-98-F-399-R1) and additional 
details can be found in that document. The Bender allotment is 1,287 
hectares (ha) (3,180 acres (ac)) and supports a 14-cow-and-calf 
operation. Grazing is allowed year-round and there is only one pasture. 
The allotment is reported to be in moderately good condition. The Lone 
Mountain allotment is 15,435 ha (38,140 ac), divided into 27 pastures. 
It supports a 1,346-cow-and-calf operation. The allotment is reported 
to be on an

[[Page 62733]]

upward trend, with 75 percent of the allotment classified as being in 
moderately high range condition. Both the Bender and Lone Mountain 
allotments are reported to be in moderately high range condition, and 
watershed degradation is not likely to be a problem in allotments that 
are maintained in good to high range conditions.
    The Coronado National Forest has a drought policy which directs 
grazing permittees to work with the Forest when rainfall for the water 
year (beginning October 1) is less than 75 percent of normal by March 1 
and the long-range forecast is for less than normal precipitation. In 
addition, critical habitat for Liliaeopsis schaffneriana var. recurva 
(Huachuca water umbel) is within the Lone Mountain allotment. As such, 
there are additional restrictions placed on the grazing practices in 
this allotment to protect occupied areas and critical habitat. Several 
areas within this allotment receive special protections, such as the 
Peterson pasture, which contains Scotia, Sycamore and Bear canyons. The 
pastures are grazed in winter (November-March) and only when winter 
rains are sufficient to provide adequate water throughout the pasture 
to encourage livestock dispersal away from the canyon bottom. 
Utilization of upland browse is not permitted to exceed 35-45 percent. 
These restrictions benefit Astragalus hypoxylus because they reduce 
impacts from livestock grazing and limit use of the upland areas during 
drought periods, when overgrazing and trampling of habitat are more 
likely to occur.
    There were a few observations of trampling on Astragalus hypoxylus 
habitat in the Bear Creek population (Johnson et al. 1992, p. 12). 
Warren et al. (1991, p. 10) notes that livestock grazing, although 
present in the area, does not seem to pose a direct threat. Livestock 
trampling may disturb the soil and disrupt seedling establishment. 
Population visits in 2001 and 2011 (Service 2010, p. 1; Service 2011b, 
p. 2) did not note the presence of livestock or trailing through the 
populations.
    Livestock have not been observed to eat Astragalus hypoxylus. Many 
species of Astragalus contain poisonous compounds, known as nitro-
toxins, which are highly toxic to livestock (Williams and Barneby 1977, 
p. 310). A. nothoxys, which sometimes grows near and in proximity to A. 
hypoxylus populations, has been tested and does contain nitro-toxins 
(Johnson et al. 1992, p. 3). Livestock have been observed to graze on 
A. nothoxys, primarily when forage is lacking (Schmutz et. al. 1968, 
pp. 26-27). The Forest Service has not indicated that this species has 
caused any problems with livestock in the Forest. Any eradication 
program to eliminate A. nothoxys could possibly harm adjacent A. 
hypoxylus; however, there is no evidence of any efforts to eradicate A. 
nothoxys. A. hypoxylus has not been tested for nitro-toxins, but many 
species in the Leptocarpa section of Astragalus (A. hypoxylus is 
classified in this section) contain these chemicals. At any rate, the 
limited distribution of A. hypoxylus and the lack of observation of 
cattle eating this plant indicates that the potential poisoning of 
livestock is unlikely.
    In summary, all populations of Astragalus hypoxylus occur in 
grazing allotments. Those grazing allotments are being managed in ways 
that promote healthy watershed and good range condition. The Lone 
Mountain allotment has additional grazing practices that protect 
riparian and upland habitat, resulting in improved watershed health, 
which benefits upland species, including A. hypoxylus. The best 
available information does not provide further evidence that livestock 
grazing is negatively affecting populations of A. hypoxylus; therefore, 
we have determined that livestock grazing is not a threat to the 
continued existence of the species now, nor is it likely to become so.
Nonnative, Invasive Species
    Nonnative species can have negative effects on the ecology of 
native plant communities, as well as individual species (Brooks et al. 
2004, p. 677; Alvarez and Cushman 2002, p. 1434; Mooney and Cleland 
2001, p. 5446). However, there are no nonnative species that have been 
detected in the populations of Astragalus hypoxylus. The only nonnative 
grass that occurs in the vicinity of these populations is Eragrostis 
lehmanniana (Lehmann lovegrass), but this grass has not been seen in 
the monitoring plots or growing in the populations (Falk 2011, pers. 
obs.). Eragrostis lehmanniana can form dense stands, increasing fine 
fuels and fire danger (Anable et al. 1992, pp. 186-187), but there are 
no continuous stands near any of the A. hypoxylus populations (Falk 
2011, pers. obs.). The best available scientific information does not 
suggest that nonnative invasive species are a threat to the continued 
existence of A. hypoxylus, nor are they likely to become so.
Fuel Wood Harvesting
    The Coronado National Forest did allow fuel wood harvesting in the 
past near the known populations. It is unknown if these past activities 
affected Astragalus hypoxylus populations. The collection of dead and 
down wood was also allowed, with a permit, but this practice was 
stopped in 1990 (Johnson et al. 1992, p. 12). Fuel wood harvesting is 
no longer allowed in these areas (Frederick 2011, pers. comm.). The 
best available information does not provide evidence that fuel wood 
harvesting is currently affecting A. hypoxylus populations; therefore, 
we have determined that fuel wood harvesting is not a threat to A. 
hypoxylus, nor is it likely to become so.
Fire
    As mentioned under Habitat and Biology, there is no information on 
Astragalus hypoxylus and fire effects. The Forest Service's Fire 
Effects Information System (http://www.fs.fed.us/database/feis/) 
contains information on 7 species of Astragalus in the United States, 
some of which are adapted to fire, and may even require fire, to 
complete one of their life cycles (i.e., seeds need to be scarified by 
fire before germinating). It is unknown if this is the case for A. 
hypoxylus, but we hypothesize that this species may be tolerant of fire 
because of the plant community where it grows and its tolerance for 
moderate disturbance, including fire. Also, fire may be important in 
maintaining habitat for A. hypoxylus by removing the overstory, thus 
reducing competition and shading. In summary, given the limited 
available information about the effect of fire on A. hypoxylus, we 
determine that fire, or lack thereof, is most likely not a threat to 
the continued existence of A. hypoxylus.
Road Maintenance
    Portions of a few of the Astragalus hypoxylus populations are near 
roads, and may be threatened by road maintenance activities, such as 
blading (clearing and smoothing the road with a large piece of 
equipment). However, the species appears to be tolerant of moderate 
disturbance. In 2010, A. hypoxylus were observed near the road going 
through Scotia Canyon. Portions of the road were well eroded, resulting 
in rills (portions of the road that are washed out, forming small 
gullies). There were 10-20 plants growing in the roadbed, on top of the 
erosion rills. These were some of the largest and healthiest plants 
observed in Scotia Canyon (Service 2010, p. 1). As mentioned 
previously, in 2011, Service biologists found 19 plants at Harshaw that 
were growing in the cutbank of the road, and these plants were larger 
and

[[Page 62734]]

healthier than the plants upslope in the area of the monitoring plot 
(Service 2011b, p. 1). This may indicate that plants are receiving 
supplemental water due to the proximity of the road and concentrated 
rainwater runoff, which may be why the plants are larger in the road 
cuts.
    Disturbed areas often afford the plants which grow on them reduced 
competition for physical resources, such as water, and reduced 
competition from other plants. However, these potential positive 
effects of disturbance on Astragalus hypoxylus are unknown because 
there have been no such studies. Regardless, there are only a few 
portions of the populations that may be subject to Forest road 
maintenance activities, and they represent a very small portion of the 
total amount of occupied habitat. In addition, road maintenance 
activities take place on a periodic basis, so the effects are likely to 
be short-term and widely spaced over time. In conclusion, A. hypoxylus 
seems to tolerate moderate disturbance, and the best available 
information does not provide evidence that road maintenance activities 
are a threat to the continued existence of the species, nor are they 
likely to become so.
Drought
    Data collected from the monitoring plots indicates that there is a 
likely correlation between rainfall and the population dynamics of 
Astragalus hypoxylus. As stated earlier, results from the Bear Canyon 
monitoring effort indicate that seedling recruitment and establishment 
was high when rainfall was high. We believe, based on data from the 
monitoring plots, that winter rainfall affects the survivorship of the 
seedlings. Summer rainfall may be important for germination, but 
without winter rainfall, the seedlings would not survive. The 
information provided in the following section was derived from data 
accessed on the National Oceanic and Atmospheric Administration (NOAA) 
National Climatic Data Center Web site (http://www.ncdc.noaa.gov). 
Rainfall totals for Arizona (Division 7), which includes all of the A. 
hypoxylus populations, for the months November through March, indicates 
a severe decline over the past 34 years. Another way to illustrate the 
decline is to use the Palmer Drought Severity Index (PDSI). The PDSI 
``attempts to measure the duration and intensity of the long-term 
drought-inducing circulation patterns.'' It is an index used to gauge 
the severity of drought conditions by using a water balance equation to 
track water supply and demand. When the historical PDSI values are 
displayed for the years 1996-2011, 12 out of the 16 years were 
classified as moderate to severe drought. In comparison, the PDSI 
values for the same months during 1950-1960 (which is a well-documented 
drought period in Arizona) classified 8 out of 10 years as moderate to 
severe drought. There are significant differences between the two 
drought periods; mainly that the current drought is much warmer than 
the 1950s drought. On average, temperatures in the Four Corners region 
of the Southwest were about 2 to 7 [deg]F (1 to 4 [deg]C) warmer than 
in the 1950s (Weiss 2009, pp. 5920-5921). Drought with higher 
temperatures creates tough growing conditions for plants because warmer 
temperatures make the air drier, and drier air absorbs more moisture 
from the soils, vegetation, and reservoirs. Thus, not only is there 
less precipitation, but there is less moisture available in the soil 
for plant growth.
    It is difficult to predict how Astragalus hypoxylus populations 
will fare with these drought conditions. The species apparently 
persisted and survived the 1950s drought; however, this information is 
of limited value as we evaluate potential conditions. The long-term 
trend for these populations is unknown; it is possible that the 
populations that are currently in decline will rebound when there is 
sufficient moisture. Despite drought conditions, A. hypoxylus 
populations in Scotia and Bear canyons seem stable, relative to the 
previous population estimates presented in Table 1. The largely 
circumstantial evidence available indicates that rainfall influences 
population dynamics for A. hypoxylus, and drought likely contributes to 
population declines. However, it is not known how the magnitude and 
intensity of drought will affect the long-term status of this species. 
Loss of individual plants, especially young plants, will likely occur 
during drought years. Dry conditions will likely reduce seed 
germination and survival. Population numbers of A. hypoxylus will 
fluctuate as observed during the period of data collection in the 
monitoring plots. However, this species is likely adapted to arid 
conditions. The ability to remain dormant during dry periods, and 
regrow when rainfall starts, is an adaptation for coping with arid 
conditions. Further, A. hypoxylus populations survived the 1950s 
drought, indicating the species has developed traits to survive during 
dry periods. Therefore, based on the best available information, we 
determine that drought is most likely not a threat to the continued 
existence of A. hypoxylus.
Climate Change
    No further specific information is available regarding the effects 
of climate change on A. hypoxylus; therefore, please refer to the 
``Climate Change'' discussion under Factor A. The Present or Threatened 
Destruction, Modification, or Curtailment of Its Habitat or Range in 
the Five-Factor Evaluation for Amoreuxia gonzalezii Section.
    As discussed in the previous sections above, Astragalus hypoxylus 
seedling establishment is likely correlated with rainfall; therefore, 
reduced precipitation may reduce seedling establishment. Additionally, 
the localized distribution of A. hypoxylus may make this species more 
susceptible to landscape-level stochastic events, such as regional 
drought. Despite these potential vulnerabilities, A. hypoxylus appears 
well-adapted to a dry climate and tolerates moderate disturbance. 
Plants growing in high-stress landscapes are adapted to stress, and 
drought-adapted species may experience lower mortality during severe 
droughts (Gitlin et al. 2006, pp. 1477, 1484).
    In summary, climate change is affecting and will affect temperature 
and precipitation events. We expect that Astragalus hypoxylus, like 
other narrow endemics, may be negatively affected by drought associated 
with climate change. However, A. hypoxylus appears to be adapted to 
arid conditions, and has survived a previous long-term drought in the 
1950s. Although climate change will likely affect plants in the future, 
the limited available information does not suggest that the effect on 
the status of the species will be significant. Therefore, based on the 
best available information, we have determined that climate change is 
not a threat to the continued existence of A. hypoxylus.
Summary of Factor A
    In conclusion, based on the best available information, we have 
determined that recreation; livestock grazing; nonnative, invasive 
species; fuel wood harvesting; fire; road maintenance; or drought do 
not threaten the continued existence of Astragalus hypoxylus. 
Recreational impacts were associated with one population, and the 
Forest Service has taken corrective action to reduce those effects. The 
remaining populations are not affected by recreational activities. The 
best available information does not provide evidence that livestock 
grazing is a threat to this species. The plant is not eaten by 
livestock, both of the grazing allotments are in good range condition, 
and measures are in place to ensure

[[Page 62735]]

protection of upland and riparian areas. Nonnative, invasive species 
are not present in or near A. hypoxylus populations; therefore, we have 
determined that they are not a threat to the species. Fuel wood 
harvesting is not allowed in the areas where A. hypoxylus is located; 
therefore, we determined that this activity is not a threat to the 
species. Given the limited available information, we have determined 
that presence or absence of fire is most likely not a threat to the 
species. Road maintenance activities may affect small portions of A. 
hypoxylus populations, but we determined that these activities are not 
a threat to the continued existence of the species because the effects 
are short-term and the plants appear tolerant of moderate disturbance. 
Drought influences the population structure of A. hypoxylus, but the 
species has survived a previous long-term drought and appears to have 
adaptations for dealing with drought, therefore, we have determined 
that drought is not a threat to the continued existence of the species. 
We acknowledge that climate change, particularly the predictions of 
reduced precipitation and increasing temperatures in the Southwest, 
will affect individuals and populations of A. hypoxylus. However, the 
plant is adapted to arid conditions, and the limited available that can 
be applied at a local scale does not suggest that climate change is 
likely to threaten A. hypoxylus. Thus, the present or threatened 
destruction, modification, or curtailment of its habitat or range is 
not a threat to the continued existence of A. hypoxylus, nor is it 
likely to become so.

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

    Astragalus hypoxylus is not a plant of horticultural interest. 
There is no evidence of any instances where A. hypoxylus was collected 
from the wild other than as voucher specimens to document occurrences 
(http://ag.arizona.edu/herbarium) or seed collection for the purposes 
of banking seed for future conservation efforts. Therefore, we have 
determined that overutilization is not a threat to the continued 
existence of the species, nor is it likely to become so.

Factor C. Disease or Predation

    There is no information indicating that disease affects Astragalus 
hypoxylus. There are no observations or evidence that A. hypoxylus is 
browsed by livestock (see Factor A, Livestock grazing). Data were 
collected on A. hypoxylus seed predation by small wasps in 1988, but it 
is unknown how this predation affected the A. hypoxylus population or 
how often seed predation occurs (Johnson et al. 1992, p. 13). Based on 
the best available information, we have determined that A. hypoxylus is 
not threatened by disease or predation, nor is it likely to become so.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    The Act requires us to examine the adequacy of existing regulatory 
mechanisms with respect to threats that may place Astragalus hypoxylus 
in danger of extinction or likely to become so in the future. Existing 
regulatory mechanisms that could have an effect on potential threats to 
A. hypoxylus include (1) Local land use laws, processes, and 
ordinances; (2) State laws and regulations; and (3) Federal laws and 
regulations. A. hypoxylus occurs entirely on Federal land under the 
jurisdiction of the Coronado National Forest; therefore, the discussion 
below focuses on Federal laws.
    Astragalus hypoxylus is listed as a sensitive species in the 
Coronado National Forest. The management of sensitive species is 
described in Forest Service Manual (FSM) 2670, and the management 
objectives are to develop and implement management practices to ensure 
that species do not become endangered or threatened because of Forest 
Service actions; maintain viable populations of all native and desired 
nonnative wildlife, fish, and plant species in habitats distributed 
throughout their geographic range on National Forest System lands; and 
develop and implement management objectives for populations or habitat 
of sensitive species or both. In addition, the Forest has to consider 
the effects of their actions on the viability of sensitive species 
through the NEPA process. As defined by Forest Service policy, actions 
must not result in loss of species viability or create significant 
trends toward the need for Federal listing. A. hypoxylus receives these 
protective measures in the Coronado National Forest, and the 
designation has resulted in measures to reduce impacts from recreation 
on the Bear Canyon A. hypoxylus population, and the consideration of 
the species' needs in the NEPA planning process for the Bender and Lone 
Mountain grazing allotments.
Summary of Factor D
    We examined the existing regulatory mechanisms that protect 
Astragalus hypoxylus. We have determined that the Forest Service 
sensitive species designation adequately protects A. hypoxylus and its 
habitat, and, thus, there is no evidence of impacts to A. hypoxylus 
from inadequate existing regulatory mechanisms. We conclude that the 
best available information indicates that A. hypoxylus is not 
threatened by inadequate existing regulatory mechanisms.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

    A threat identified by the petition was indirect effects to 
pollinators, mainly bees. Johnson et al. (1992, p. 13) noted that the 
use of pesticides to control insects, such as grasshoppers, may be 
harmful to bees. The Coronado National Forest has not sprayed 
pesticides for grasshopper control, and has no plans to do so. As 
mentioned previously, the pollinators for Astragalus hypoxylus have not 
been identified. As such, there is no evidence of activities that may 
harm the potential pollinators of this species; therefore, we have 
determined that the loss of pollinators from pesticide spraying is not 
a threat to the species.
    We are not aware of any other potential threats related to this 
factor, such as small population size and overall rarity. Therefore, we 
find that Astragalus hypoxylus is not threatened by small population 
size and overall rarity, or is likely to become so.

Finding for Astragalus hypoxylus

    As required by the Act, we evaluated the five factors in assessing 
whether Astragalus hypoxylus is endangered or threatened throughout all 
or a significant portion of its range. We examined the best scientific 
and commercial information available regarding the past, present, and 
future threats faced by A. hypoxylus. We reviewed the petition, 
information available in our files, other available published and 
unpublished information, and we consulted with recognized plant experts 
and Forest Service biologists.
    Astragalus hypoxylus populations are primarily affected by drought; 
however, we determined that drought is not a threat to this species. 
The plants are tolerant of moderate disturbance, and are adapted to 
arid conditions, as evidenced by their survival during the 1950s 
drought. Climate change will likely impact the status of A. hypoxylus 
in the future; however, the limited available information suggests that 
climate change will not threaten the continued existence of the 
species. Other factors potentially affecting A. hypoxylus--including 
recreation;

[[Page 62736]]

livestock grazing; nonnative, invasive species; fuel wood harvesting; 
fire; and effects to potential pollinators--are either limited in 
scope, or available evidence is lacking to indicate that they adversely 
impact the species. There is no evidence that overutilization, disease, 
or predation is affecting this species. In addition, we find that the 
existing regulatory mechanisms are not a threat to the species.
    Based on our review of the best available scientific and commercial 
information pertaining to the five factors, we find that the threats 
are not of sufficient imminence, intensity, or magnitude to indicate 
that Astragalus hypoxylus is in danger of extinction (endangered), or 
likely to become endangered within the foreseeable future (threatened), 
throughout all of its range.

Significant Portion of the Range

    Having determined that Astragalus hypoxylus is not in danger of 
extinction, or likely to become so, throughout all of its range, we 
must next consider whether there are any significant portions of the 
range where A. hypoxylus is in danger of extinction or is likely to 
become endangered in the foreseeable future. We also considered the 
historical range of the species, and have determined that the current 
range is no different from the historical range. Therefore, there has 
been no loss of the historical range, and no further analysis of the 
historical range is required.
    The Act defines an endangered species as one ``in danger of 
extinction throughout all or a significant portion of its range,'' and 
a threatened species as one ``likely to become an endangered species 
within the foreseeable future throughout all or a significant portion 
of its range.'' The term ``significant portion of its range'' is not 
defined by the statute. For the purposes of this finding, a portion of 
a species' range is ``significant'' if it is part of the current range 
of the species, and it provides a crucial contribution to the 
representation, resiliency, or redundancy of the species. For the 
contribution to be crucial it must be at a level such that, without 
that portion, the species would be in danger of extinction.
    In determining whether Astragalus hypoxylus is endangered or 
threatened in a significant portion of its range, we considered status 
first to determine if any threats or potential threats acting 
individually or collectively threaten or endanger the species in a 
portion of its range. We evaluated the current range of A. hypoxylus to 
determine if there is any apparent geographic concentration of the 
primary stressors potentially affecting the species including 
recreation; livestock grazing; nonnative, invasive plants; fuel wood 
harvesting; fire; road maintenance; and drought. We have analyzed the 
stressors to the degree possible, and determined that they are 
essentially uniform throughout the species' range. We also found the 
stressors are not of sufficient imminence, intensity, magnitude, or 
geographically concentrated such that it warrants evaluating whether a 
portion of the range is significant under the Act. We do not find that 
A. hypoxylus is in danger of extinction now, nor is likely to become 
endangered within the foreseeable future, throughout all or a 
significant portion of its range. Therefore, listing A. hypoxylus as an 
endangered or threatened species under the Act is not warranted at this 
time.
    We request that you submit any new information concerning the 
distribution and status of, or threats to, Astragalus hypoxylus to our 
U.S. Fish and Wildlife Service Office (see ADDRESSES section) whenever 
it becomes available. New information will help us monitor A. hypoxylus 
and encourage its conservation. If an emergency situation develops for 
A. hypoxylus, or any other species, we will act to provide immediate 
protection.

Species Information for Erigeron piscaticus

Species Description

    Erigeron piscaticus is a herbaceous annual (a plant that completes 
its life-cycle in one year) in the Asteraceae (Sunflower) family. The 
plant is typically 15 to 40 cm (6 to 16 in) in height, multi-branched, 
procumbent or ascending--decumbent (trailing or lying on the ground), 
and densely pubescent (covered with hair) with coarse, stiff hair. One 
to 4 flower heads are produced per plant, each 5 to 7 mm (0.2 to 0.3 
in) across with a white corolla (ray and disk flowers), and producing 
tan-colored achenes (fruit) to 1 mm (0.04 in) in length. The very small 
flower heads, coupled with entire (toothless) leaves are key factors 
distinguishing this species from close relatives (Nesom 1989, p. 306).

Habitat and Biology

    Oak Grove Canyon, where the plant has been most recently located, 
is a narrow slot canyon with intermittent stream flow and a riparian 
gallery forest of sycamore, alder, and black walnut (Gori 1992, p. 2). 
Occurring at 1,000-m (3,300-ft) elevation, its steep (91 to 122 m) (300 
to 400 ft)) canyon walls and northeast aspect provide for significantly 
cooler temperatures than the semidesert grasslands in the adjacent 
uplands (Haberstich 2011, pers. comm.). The plants are found on sandy 
terraces just above the floodplain and are subject to larger flood 
events; there is little associated understory (Gori 1992, p. 2). A 
single collection from Turkey Creek refers to a ``riparian woodland'' 
habitat, while the specimen from Fish Creek has no habitat information 
recorded. The collection from near Tucson refers to the plant being 
found ``in rock adjacent to stream.'' (Southwest Environmental 
Information Network 2011)
    Erigeron piscaticus germinates following either winter or summer 
rains (Arizona Game and Fish Department (AZGD) Heritage Data Management 
2001, p. 2), grows quickly, and has a long flowering period from May 
through October (Gori 1992, p. 2) or possibly through December 
(Southwest Environmental Information Network, 2011). Pollination has 
not been studied in this species, though other Erigeron species are 
typically pollinated by bees and wasps (Tepedino 2011, pers. comm.). 
Seed is dispersed by both wind and water; this species may also depend 
on flooding events to create suitable early-successional habitat (Gori 
1992, p. 2). Seed bank longevity has not been studied in E. piscaticus.
    Soil moisture is necessary for most annual plants to germinate and 
flower; therefore, seed production in most annuals is equally limited 
by soil moisture. Following this theory, Gori (1992, p. 3) suggested 
that Erigeron piscaticus populations would increase or decrease in 
sequential years of above- or below-average moisture. In the case of 
data collected at Oak Grove Canyon, this theory held in 1993, a wet 
year, when both 1994 and 1995 had high population numbers (79 and 68 
respectively). However, the theory did not hold in 2002, a dry year, 
when 23 plants were found in 2003 followed by 64 plants in 2004. It is 
likely that this species instead responded to flooding that occurred in 
1993 and not to precipitation. There is not sufficient data available 
to determine the ecological factors that influence the germination of 
this species.

Distribution, Abundance, and Trends

    Erigeron piscaticus is ranked by NatureServe as G1S1 (Global and 
State Critically Imperiled). The species is known from two confirmed 
areas: Fish Creek Canyon and the Aravaipa Canyon Preserve of south-
central Arizona. There are three populations in the Aravaipa Canyon 
Preserve; one is located in Turkey Creek Canyon, and the

[[Page 62737]]

remaining two populations are in Oak Grove Canyon. An additional site 
is currently under investigation in the mountains near Tucson. The 
herbarium specimen location for this third site states ``Box Canyon 
southwestern corner of Santa Catalina Mountains;'' the specimen was 
verified by Guy Nesom, the botanist who described the species 
(Southwest Environmental Information Network 2011). There have been 
discussions among botanists, however, that this location may be 
incorrect and Box Canyon could refer to either the Rincon or Santa Rita 
Mountains. It is also possible that the specimen was misidentified and 
the location is correct. The specimen currently resides at the New York 
Botanic Garden Herbarium and a loan has been requested by Shelley 
McMahon of the University of Arizona Herbarium for reverification. 
Surveys for the species are planned in 2012 (Crawford 2011, pers. 
comm.).
    The species was first collected on the Tonto National Forest in 
Fish Creek Canyon in October 1929 by Eastwood, then again in 1931 by 
Peebles and Eaton (Nesom 1989, p. 305). Erigeron piscaticus was not 
collected again until 1976 in Turkey Creek then in 1979 in Oak Grove 
Canyon by Anderson and Warren (Southwest Environmental Information 
Network 2011). In 2002, a second group of plants was located in Oak 
Grove Canyon and those plants are counted as part of an annual census 
for the canyon as a whole (Haberstich and Killeen 2002, p. 1). Both 
Turkey Creek and Oak Grove Canyon are within the Aravaipa Canyon 
Preserve on Bureau of Land Management land managed jointly with The 
Nature Conservancy. The two locations within Oak Grove Canyon are 
approximately 0.8 km (0.5 mi) apart by air and the Oak Grove 
populations are approximately 3.7 air km (2.3 air mi) from the 
collection site in Turkey Creek. The Fish Creek locations are 
approximately 129 air km (80 air mi) from those in Aravaipa Preserve. 
There are many canyons supporting what seems to be suitable habitat 
between the known locations in Fish Creek and the Aravaipa Canyon 
Preserve. Several surveys have been completed, and no additional 
populations have been located (Gori 1991, p. 2).
    Attempts were made in 1990 to locate the populations in both Fish 
Creek and Turkey Creek again, but none were found (Gori and Malusa 
1991, p. 2). The Arizona Game and Fish Department reports 11 plants 
were located in Turkey Creek in 1992, although no other records 
indicate the plant has been found in Turkey Creek since its first 
collection in 1976. A letter in the files from Dave Gori to Dan Godec 
of the Arizona Game and Fish Department dated June 12, 1998 stated that 
E. piscaticus has not been relocated in Fish Creek Canyon or Turkey 
Creek Canyon. He related that, to his knowledge, there were ``no other 
extant locations for this plant except Oak Grove Canyon.'' It is 
unknown how many plants originally occurred at collection sites in Fish 
Creek or Turkey Creek Canyons. As these populations have not been 
detected again, it is unknown if they are extant or what the current 
population sizes are. Annual monitoring of plants in Oak Grove Canyon 
took place between 1992 and 2008 and is scheduled to occur in the 
summer of 2011 (Haberstich 2011, pers. comm.). These efforts show plant 
numbers fluctuating annually, ranging from 87 individuals in 1992, to 4 
individuals in 2002, and back to 81 individuals in 2008.
    To summarize, there is very little biological and ecological 
information known about this species. There are three known locations, 
but plants have not been seen in the original location, Fish Creek, 
since the 1930s. Today, plants are known from two locations, Oak Creek 
Canyon and Turkey Creek on the Aravaipa Canyon Preserve. There may be 
another location in the Santa Catalina Mountains, near Tucson, but it 
has not been verified. The species seem to be associated with 
floodplain terraces in riparian areas, but that is based on their 
current locations in the Aravaipa Canyon Preserve. The species may 
respond to rainfall, or germination may be triggered by flooding, or 
the apt combination of rainfall and flooding.

Five-Factor Evaluation for Erigeron piscaticus

    In making this finding, information pertaining to Erigeron 
piscaticus 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 Erigeron 
piscaticus are discussed in this section, including: (1) Flooding; (2) 
recreation; (3) watershed degradation; and (4) climate change.
Flooding
    Many annual and short-lived perennial plant species have a high 
rate of seed production and the ability to thrive following 
disturbance. Annual plants in the southwestern United States often 
increase in richness and cover following the disturbance of large flood 
events (Bagstad et al. 2005, p. 219). These events reduce competition 
with perennial plants, increase understory light, remove litter 
accumulation from overstory tree species, redistribute seed banks, and 
create nutrient-rich sediment beds for seed germination. Plants found 
above the inundation zones on high flood-plain surfaces respond most to 
the increased rainfall that led to flooding, while those in inundation 
zones respond most to the physical disturbance of flooding (Bagstad et 
al. 2005, p. 219, 221). Erigeron piscaticus is an annual riparian 
species that occurs above the inundation zone on shallow terraces that 
are subject to larger flooding events.
    Census data for this species were collected on a nearly annual 
basis between 1992 and 2008, in one of two locations within the 
Aravaipa Canyon Preserve, in southeastern Arizona. Plant census data 
were compared against regional precipitation data during this time 
period, and no correlation was observed. In other words, population 
peaks varied between wet (1991 through 1995) and dry (2004 and 2008) 
years (NOAA 2011; Haberstich and Walker 2008, p. 1; Haberstich 2005, p. 
1; Haberstich and Killeen 2004, p. 1; 2003, p. 1; 2002, p. 1; 
Haberstich 2011, pers. comm.). Aravaipa Creek has experienced 
significant flooding on four occasions (1979, 1984, 1993, and 2006) 
since stream flow gage records were first kept in 1932 (USGS, 2011). 
Erigeron piscaticus may be more closely associated with the physical 
scouring from flooding than with precipitation. E. piscaticus 
populations peaked following both the 1993 and 2006 floods.
    Although periodic flooding events remove individual plants and 
seeds, total Erigeron piscaticus population numbers were very similar 
during the 2008 monitoring (81) to numbers the first time the species 
was monitored in 1992 (87). There is, however, great year-to-year 
variability in the census data, both in terms of population numbers (as 
low as 4 plants in 2002, and as high as 87 plants in 1992) and 
population locations (lower, middle, and upper sections of the canyon). 
The species seems to establish, increase and decrease; disperse via 
water or wind; and move to different locations within the canyon, which 
may explain the new location discovered downstream from known sites in 
2002. In addition, in particularly dry years, plants may not germinate. 
This may explain why certain populations, like Fish Creek, have never 
been found again. If the populations are not present every year, and 
the location may move within the canyon based on flooding, it is easy 
to

[[Page 62738]]

understand why populations need regular and consistent monitoring.
    Erigeron piscaticus seems to be well adapted to its environment and 
may require periodic flooding for survival. Too many large floods, 
however, could deplete the seed bank; too few large floods could lead 
to competition with perennial plants and litter accumulation (Gori 
1992, p 3). We are making this conclusion based on the behavior of one 
population; however, this population may not be representative of the 
species. We conclude that E. piscaticus is tolerant of moderate 
disturbance and may need periodic flooding for successful seed 
germination. Therefore, based on the best available information, we 
determined that flooding is not a threat to the continued existence of 
E. piscaticus, nor is it likely to become so.
Recreation
    Erigeron piscaticus plants are located near hiking and game trails 
in Oak Grove Canyon. Hiking and other forms of recreation, including 
all-terrain vehicle (ATV) use, occur frequently in the Aravaipa Canyon 
Preserve (Haberstich 2005, p. 1; Haberstich and Killeen 2004, p. 1). As 
stated above, this species seems to tolerate moderate levels of 
disturbance. The populations in Oak Grove Canyon seem to be persisting 
despite the levels of traffic, both human and ATV, that occur adjacent 
to and through the populations. There are also observations (Haberstich 
2005, p. 1; Haberstich and Killeen 2004, p. 1) that E. piscaticus 
plants were found in various stages of germination and growth on an 
actively eroding site, another indication that the species tolerates 
disturbance. Impacts from recreation may have contributed to the loss 
of the Turkey Creek population in the Aravaipa Canyon Preserve, as the 
site was used as a casual camping site (AZGF Heritage Data Management 
2001, p. 3). However, there is no documentary evidence that that is the 
case, and because no one has surveyed that area since the 1990s, there 
is no conclusive evidence that the population has been extirpated. In 
summary, E. piscaticus seems to tolerate disturbance, and, based on the 
best available information, we find that recreation is not a threat to 
the continued existence of this species, nor is it likely to become so.
Watershed Degradation
    The Aravaipa Canyon watershed has a history of intense grazing by 
cattle, horses, and goats. This grazing occurred from the 1850s until 
the 1980s when grazing was removed from portions of the area and a 
pasture rotation system was initiated in other areas (Gori 1992, p. 4). 
By 1997, the entire area, including Oak Grove and Turkey Creek Canyons, 
was free of domestic grazing activity (Haberstich 2011, pers. comm.). 
The years of intense grazing, coupled with fire suppression, 
significantly altered plant species composition and abundance, and led 
to a degraded condition of the upland vegetation of the area (Gori 
1992, pp. 3-4). By the 1980s, this upland semidesert grassland was 
described as being largely comprised of shrubs and annual grasses, an 
unnatural condition that reduces water infiltration and can cause more 
intense sheet flow during storm events (Gori 1999, pp. 41-42). Great 
strides have been made in recent decades to correct this problem. 
Preserve Manager Mark Haberstich reports that the uplands are fairly 
healthy with increases in native perennial grasses, thus reducing 
runoff and erosion (Haberstich 2011, pers. comm.). There is no evidence 
that watershed degradation is affecting E. piscaticus populations in 
the Aravaipa Canyon Preserve. Therefore, based on our review of the 
best available information, we conclude that watershed degradation is 
not a threat to the continued existence of this species, nor is it 
likely to become so.
Climate Change
    For general background information on climate change, please refer 
to the first paragraphs of ``Climate Change'' under Factor A. The 
Present or Threatened Destruction, Modification, or Curtailment of Its 
Habitat or Range in the Five-Factor Evaluation for Amoreuxia gonzalezii 
section.
    It has been suggested that this species may be a relict of the last 
ice age due to its very restricted habitat of cool, shady, narrow, and 
steep slot canyons in perennial stream bottoms (Haberstich 2011, pers. 
comm.). If this is the case, recent and projected increases in regional 
daily temperatures and decreases in winter precipitation could 
negatively impact Erigeron piscaticus. Direct impacts due to rising 
temperature are unknown for this plant, although heat stress in plants 
in general is known to impact germination, photosynthesis, respiration, 
and a myriad of other functions (Wahid et al. 2007, p. 199). A 
reduction in precipitation or increase in temperature-related stress 
could preclude recruitment and therefore seed set in this annual 
species. Seed bank longevity for E. piscaticus has not been determined, 
although Bagstad et al. (2005, p. 219) state that ``many of the annual 
plant species found in southwestern riparian areas have long-lived 
seeds that are widely distributed in soil seed banks across the flood 
plain, enabling them to establish opportunistically when suitable 
germination sites develop.'' Similarly, other Erigeron seeds have been 
reported to last roughly 10 years with no refrigeration (Murray 2011, 
pers. comm.).
    The information related to the effects of climate change on 
Erigeron piscaticus at a local scale is limited. Predicted changes in 
rainfall, temperature, and flooding frequency may all affect E. 
piscaticus. However, based on the species' life history and observed 
tolerances, it appears that the effects of climate change may be 
limited. In conclusion, based on the best available information, we 
have determined that climate change is not a threat to the continued 
existence of E. piscaticus.
Summary of Factor A
    Based on the best available information, we have determined that 
flooding, recreation, watershed degradation, and climate change do not 
threaten Erigeron piscaticus, nor are they likely to do so. Flooding 
seems to play an important role in the germination and survival of E. 
piscaticus populations. As such, the species seems to tolerate moderate 
levels of disturbance, making the populations less vulnerable to 
impacts from recreation, such as hiking and ATV use. The watershed 
condition of Aravaipa Canyon has recovered from past grazing, and there 
is no evidence that E. piscaticus populations have been affected by 
watershed degradation. We acknowledge that climate change, particularly 
the predictions of reduced precipitation and increasing temperatures in 
the Southwest, may affect populations of E. piscaticus; however, the 
limited available information at the local scale suggests that a 
climate change will likely not be a threat to the continued existence 
of the species. Thus, the present or threatened destruction, 
modification, or curtailment of the habitat or range is not a threat to 
the continued existence of E. piscaticus, nor is it likely to become 
so.

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

    Erigeron piscaticus is not a plant of horticultural interest. There 
is no evidence of any instances in which E. piscaticus was collected 
from the wild other than as voucher specimens to document occurrences 
(http://ag.arizona.edu/herbarium). Therefore, we conclude, based on the 
best available information, that overutilization is not a threat to the 
continued existence of the species, nor is it likely to become so.

[[Page 62739]]

Factor C. Disease or Predation

    There is no indication that any disease affects Erigeron 
piscaticus. There is no livestock grazing in Oak Grove Canyon and 
Turkey Creek on the Aravaipa Canyon Preserve, and there is no 
information about any other source of predation on the species. 
Therefore, we have determined that disease or predation is not a threat 
to this species' continued existence, nor is it likely to become so.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    The Act requires us to examine the adequacy of existing regulatory 
mechanisms with respect to threats that may place Erigeron piscaticus 
in danger of extinction or likely to become so in the future. Existing 
regulatory mechanisms that could have an effect on potential threats to 
E. piscaticus include (1) Local land use laws, processes, and 
ordinances; (2) State laws and regulations; and (3) Federal laws and 
regulations. E. piscaticus occurs entirely on Federal land under the 
jurisdiction of the Bureau of Land Management (BLM) and the Tonto 
National Forest; therefore, the discussion below focuses on Federal 
laws.
    Erigeron piscaticus is listed as a BLM sensitive species (BLM, 
2010). The management of sensitive species is described in the BLM 
Manual Section 6840, which states that the BLM will focus sensitive 
species management on maintaining species habitat in functional 
ecosystems, ensuring the species is considered in land management 
decisions, and prioritizing conservation that emphasizes habitat needs 
for the species, thereby preventing the need to list the species under 
the Act.
    Erigeron piscaticus is also listed as a sensitive species in the 
Tonto National Forest (Tonto National Forest 2004, entire). The 
management of sensitive species is described in U.S. Forest Service 
Manual (FSM) 2670, and the management objectives are to develop and 
implement management practices to ensure that species do not become 
endangered or threatened because of Forest Service actions; maintain 
viable populations of all native and desired nonnative wildlife, fish, 
and plant species in habitats distributed throughout their geographic 
range on National Forest System lands; and develop and implement 
management objectives for populations or habitat of sensitive species, 
or both. In addition, the Forest has to consider the effects of their 
actions on the viability of sensitive species through the NEPA process. 
As defined by Forest Service policy, actions must not result in loss of 
species viability or create significant trends toward the need for 
Federal listing. E. piscaticus receives these protective measures in 
the Tonto National Forest.
Summary of Factor D
    We examined the existing regulatory mechanisms that protect 
Erigeron piscaticus. We have determined that the BLM and Forest Service 
sensitive species designation adequately protects E. piscaticus and its 
habitat and, thus, there is no evidence of impacts to E. piscaticus 
from inadequate existing regulatory mechanisms. We conclude that the 
best available information indicates that E. piscaticus is not 
threatened by inadequate existing regulatory mechanisms.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

Small Population Size
    Small populations can be especially vulnerable to environmental 
disturbances such as habitat loss, nonnative species, grazing, and 
climate change (Barrett and Kohn 1991, p. 7; Oostermeijer 2003, p. 21; 
O'Grady 2004, pp. 513-514). However, plants that are historically rare 
may have certain adaptations to rarity (e.g., early blooming, extended 
flowering, or mixed-mating systems) that enable them to persist 
(Brigham 2003, p. 61). For more information on species rarity and its 
effects on the conservation status of a species, see the discussion 
under Factor E. Other Natural or Manmade Factors Affecting Its 
Continued Existence in the Five-Factor Evaluation for Amoreuxia 
gonzalezii.
    There is no indication that Erigeron piscaticus was ever present on 
the landscape over a more extensive range than it is today. Existing 
sites are monitored, and surveys have located no new occurrences. There 
is no information indicating that random demographic or environmental 
events are a threat to the continued existence of the species because 
of its small population size.
Genetic Diversity
    Small population size can decrease genetic diversity due to genetic 
drift (the random change in genetic variation each generation), and 
inbreeding (mating of related individuals) (Antonovics 1976, p. 238; 
Ellstrand and Elam 1993, pp. 218-219). Genetic drift can decrease 
genetic variation within a population by favoring certain 
characteristics and, thereby, increasing differences between 
populations (Ellstrand and Elam 1993, pp. 218-219). Self-fertilization 
and low dispersal rates can cause low genetic diversity due to 
inbreeding (Antonovics 1976, p. 238; Barrett and Kohn 1991, p. 21). 
This decreased genetic diversity diminishes a species' ability to adapt 
to the selective pressures of a changing environment (Newman and Pilson 
1997, p. 360; Ellstrand 1992, p. 77).
    Limited information is available regarding the genetic diversity of 
the Erigeron genus. No information is available regarding the genetic 
diversity exhibited by E. piscaticus. Therefore, we have determined 
that a lack of genetic diversity is not a threat to the continued 
existence of the species.
Summary of Factor E
    Erigeron piscaticus is a rare species known from two locations, 
Fish Creek Canyon and the Aravaipa Canyon Preserve. Currently, there 
are two known populations in Oak Creek Canyon, within the Aravaipa 
Canyon Preserve. The other populations of E. piscaticus in Fish Creek 
Canyon and Turkey Creek Canyon, in the Aravaipa Canyon Preserve, have 
not been seen in quite some time. There is no evidence that this 
species was at one time more widespread than its current distribution. 
There is no information that E. piscaticus populations are subject to 
threats resulting from small population size. The same conclusion is 
drawn for the lack of genetic diversity that may affect small 
populations. Therefore, based on the best available information, we 
have determined that small population size and lack of genetic 
diversity are not threats to the continued existence of E. piscaticus, 
nor are they likely to become so.

Finding for Erigeron piscaticus

    As required by the Act, we considered the five factors in assessing 
whether Erigeron piscaticus is endangered or threatened throughout all 
or a significant portion of its range. We examined the best scientific 
and commercial information available regarding the past, present, and 
future threats faced by E. piscaticus. We reviewed the petition, 
information available in our files, other available published and 
unpublished information, and we consulted with recognized plant experts 
and land managers.
    Erigeron piscaticus populations do not seem to face any obvious 
threats. The species is an annual, which means that there is less 
certainty about the size, location, and permanence of any given site. 
In addition, the species tolerates,

[[Page 62740]]

and may possibly require, disturbance in order to complete its life 
cycle. The only available information is monitoring data from one 
location, and two of the other locations have not been seen in quite 
some time, although attempts to find these populations again have not 
occurred. As such, there is an incomplete set of information about this 
species, which makes it difficult to assess threats and make valid 
predictions on how potential threats may affect E. piscaticus. For 
instance, climate change will affect temperature and precipitation in 
the Southwest, but it is not known what that means for changes in 
flooding, and how that will affect E. piscaticus.
    Other factors potentially affecting Erigeron piscaticus--including 
recreation and watershed degradation--are either limited in scope, or 
lacking evidence indicating that they adversely impact the species. 
There is no evidence that overutilization, disease, or predation are 
affecting this species. Although the existing populations are small, 
there is no evidence that the populations are subject to a lack of 
genetic diversity or are more vulnerable to stochastic events. In 
addition, we conclude that the inadequacy of existing regulatory 
mechanisms is not a threat to the species.
    Based on our review of the best available scientific and commercial 
information pertaining to the five factors, we find that the threats 
are not of sufficient imminence, intensity, or magnitude to indicate 
that Erigeron piscaticus is in danger of extinction (endangered) or 
likely to become endangered within the foreseeable future (threatened), 
throughout all of its range.

Significant Portion of the Range

    Having determined that Erigeron piscaticus is not in danger of 
extinction, or likely to become so, throughout all of its range, we 
must next consider whether there are any significant portions of the 
range where E. piscaticus is in danger of extinction or is likely to 
become endangered in the foreseeable future. We also considered the 
historical range of the species, and have determined that the current 
range is no different from the historical range. Therefore, there has 
been no loss of the historical range, and no further analysis of the 
historical range is required.
    The Act defines an endangered species as one ``in danger of 
extinction throughout all or a significant portion of its range,'' and 
a threatened species as one ``likely to become an endangered species 
within the foreseeable future throughout all or a significant portion 
of its range.'' The term ``significant portion of its range'' is not 
defined by the statute. For the purposes of this finding, a portion of 
a species' range is ``significant'' if it is part of the current range 
of the species, and it provides a crucial contribution to the 
representation, resiliency, or redundancy of the species. For the 
contribution to be crucial it must be at a level such that, without 
that portion, the species would be in danger of extinction.
    In determining whether Erigeron piscaticus is endangered or 
threatened in a significant portion of its range, we considered status 
first to determine if any threats or potential threats acting 
individually or collectively threaten or endanger the species in a 
portion of its range. We evaluated the current range of E. piscaticus 
to determine if there is any apparent geographic concentration of the 
primary stressors potentially affecting the species including flooding, 
recreation, and watershed degradation. We have analyzed the stressors 
to the degree possible, and determined that they are essentially 
uniform throughout the species' range. We also found the stressors are 
not of sufficient imminence, intensity, magnitude, or geographically 
concentrated such that it warrants evaluating whether a portion of the 
range is significant under the Act. We do not find that E. piscaticus 
is in danger of extinction now, nor is likely to become endangered 
within the foreseeable future, throughout all or a significant portion 
of its range. Therefore, listing E. piscaticus as an endangered or 
threatened species under the Act is not warranted at this time.

Conclusion of 12-Month Finding

    We find that Amoreuxia gonzalezii (Santa Rita yellowshow), 
Astragalus hypoxylus (Huachuca milk-vetch), and Erigeron piscaticus 
(Fish Creek fleabane) are not in danger of extinction now, nor is any 
of these three species likely to become endangered within the 
foreseeable future throughout all or a significant portion of their 
ranges. Therefore, listing any of these three species as endangered or 
threatened under the Act is not warranted at this time.
    We request that you submit any new information concerning the 
distribution and status of, or threats to, Erigeron piscaticus to our 
U.S. Fish and Wildlife Service Office (see ADDRESSES section) whenever 
it becomes available. New information will help us monitor E. 
piscaticus and encourage its conservation. If an emergency situation 
develops for E. piscaticus or any other species, we will act to provide 
immediate protection.

References Cited

    A complete list of references cited is available on the Internet at 
http://www.regulations.gov and upon request from the U.S. Fish and 
Wildlife Service, Arizona Ecological Services Field Office (see 
ADDRESSES section).

Authors

    The primary authors of this finding are the staff members of the 
Arizona Ecological Services Field Office.

Authority

    The authority for this action is section 4 of the Endangered 
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: September 22, 2011.
Gregory E. Siekaniec,
Acting Director, Fish and Wildlife Service.
[FR Doc. 2011-25470 Filed 10-7-11; 8:45 am]
BILLING CODE 4310-55-P