Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Astragalus lentiginosus var. coachellae, 53224-53254 [2011-21442]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 76, Number 165 (Thursday, August 25, 2011)]
[Proposed Rules]
[Pages 53224-53254]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-21442]



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Vol. 76

Thursday,

No. 165

August 25, 2011

Part III





Department of the Interior





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Fish and Wildlife Service





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50 CFR Part 17





 Endangered and Threatened Wildlife and Plants; Designation of Critical 
Habitat for Astragalus lentiginosus var. coachellae; Proposed Rule

Federal Register / Vol. 76 , No. 165 / Thursday, August 25, 2011 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R8-ES-2011-0064; MO 92210-0-0009]
RIN 1018-AX40


Endangered and Threatened Wildlife and Plants; Designation of 
Critical Habitat for Astragalus lentiginosus var. coachellae

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
revise designated critical habitat for Astragalus lentiginosus var. 
coachellae (Coachella Valley milk-vetch) under the Endangered Species 
Act of 1973, as amended (Act). In total, we are proposing approximately 
25,704 acres (10,402 hectares) as critical habitat for this taxon in 
Riverside County, California.

DATES: We will accept comments received or postmarked on or before 
October 24, 2011. We must receive requests for public hearings, in 
writing, at the address shown in the FOR FURTHER INFORMATION CONTACT 
section by October 11, 2011.

ADDRESSES: You may submit comments by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: https://www.regulations.gov. Search for Docket No. FWS-R8-ES-2011-0064, which 
is the docket number for this rulemaking.
    (2) By hard copy: Submit by U.S. mail or hand-delivery to: Public 
Comments Processing, Attn: FWS-R8-ES-2011-0064; Division of Policy and 
Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax 
Drive, MS 2042-PDM; Arlington, VA 22203.
    We will post all comments on https://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see the Public Comments section below for more information).

FOR FURTHER INFORMATION CONTACT: Jim Bartel, Field Supervisor, U.S. 
Fish and Wildlife Service, Carlsbad Fish and Wildlife Office, 6010 
Hidden Valley Rd., Ste. 101, Carlsbad, CA 92011; telephone 760-431-
9440; facsimile 760-431-5902. If you use a telecommunications device 
for the deaf (TDD), call the Federal Information Relay Service (FIRS) 
at 800-877-8339.

SUPPLEMENTARY INFORMATION: 

Public Comments

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments or information from other concerned government agencies, the 
scientific community, industry, or any other interested party 
concerning this proposed rule. We particularly seek comments 
concerning:
    (1) The reasons why we should or should not designate particular 
habitat as ``critical habitat'' under section 4 of the Act (16 U.S.C. 
1531 et seq.) including whether there are threats to the taxon (the 
term taxon, as used herein, refers to any taxonomic rank that is not a 
species (for example, a genus, a subspecies, or a variety); Astragalus 
lentiginosus var. coachellae is a variety) from human activity, the 
degree of which can be expected to increase due to the designation, and 
whether that increase in threat outweighs the benefit of designation 
such that the designation of critical habitat may not be prudent.
    (2) Specific information on:
    (a) The amount and distribution of Astragalus lentiginosus var. 
coachellae habitat;
    (b) What areas, that were occupied at the time of listing (or are 
currently occupied) and that contain features essential to the 
conservation of the taxon, should be included in the designation and 
why;
    (c) Special management considerations or protection that may be 
needed in critical habitat areas we are proposing, including managing 
for the potential effects of climate change; and
    (d) What areas, that were not occupied at the time of listing, are 
essential for the conservation of the taxon and why.
    (3) Land use designations and current or planned activities in the 
subject areas and their possible impacts on proposed critical habitat.
    (4) Information on the projected and reasonably likely impacts 
associated with climate change on Astragalus lentiginosus var. 
coachellae and proposed critical habitat.
    (5) What areas, extent, and quality of the unoccupied fluvial 
(water) sand transport systems in the Coachella Valley and surrounding 
hills and mountains are essential to the conservation of Astragalus 
lentiginosus var. coachellae and should be included in the designation 
and why.
    (6) Any probable economic, national security, or other relevant 
impacts of designating any area that may be included in the final 
designation; in particular, any impacts on small entities, families, or 
tribes, and the benefits of including or excluding areas that exhibit 
these impacts.
    (7) Which specific areas within tribal lands proposed for critical 
habitat should be considered for exclusion under section 4(b)(2) of the 
Act, and whether the benefits of potentially excluding any specific 
tribal lands outweigh the benefits of including that area, in 
particular for tribal lands owned or managed by the Morongo Band of 
Mission Indians (formerly the Morongo Band of Cahuilla Mission Indians 
of the Morongo Reservation) or the Agua Caliente Band of Cahuilla 
Indians of the Agua Caliente Indian Reservation.
    (8) Which specific lands covered by the Coachella Valley Multiple 
Species Habitat Conservation Plan/Natural Community Conservation Plan 
(Coachella Valley MSHCP/NCCP) proposed as critical habitat should be 
considered for exclusion under section 4(b)(2) of the Act, and whether 
the benefits of potentially excluding any specific area covered by the 
Coachella Valley MSHCP/NCCP outweigh the benefits of including that 
area. We are currently considering all lands covered by the Coachella 
Valley MSHCP/NCCP and proposed as critical habitat for exclusion under 
section 4(b)(2) of the Act (see the Habitat Conservation Plan Lands--
Exclusions under Section 4(b)(2) of the Act section below).
    (9) What specific actions the Coachella Valley Association of 
Governments (CVAG) has undertaken to meet the objectives and goals set 
out in the Coachella Valley MSHCP/NCCP specific to Astragalus 
lentiginosus var. coachellae since CVAG began implementing the MSHCP/
NCCP.
    (10) Whether there are any other lands covered by habitat 
conservation plans or other conservation actions that benefit 
Astragalus lentiginosus var. coachellae and should be considered for 
exclusion under section 4(b)(2) of the Act, where the benefits of 
potentially excluding any specific area outweigh the benefits of 
including that area.
    (11) Whether we could improve or modify our approach to designating 
critical habitat in any way to provide for greater public participation 
and understanding, or to better accommodate public concerns and 
comments.
    (12) The validity of our approach for determining the extent of the 
fluvial sand transport system, and differentiating between fluvial sand 
transport and fluvial sand source areas. We identified fluvial sand 
source areas (areas where sediment is eroded from

[[Page 53225]]

parent rock by moving water) as portions of drainages where slope is 10 
percent or greater and fluvial sand transport areas (corridors along 
which water transports sediment, but little erosion of parent rock 
takes place) as portions of drainages where slope is less than 10 
percent. This approach was informed by Griffiths et al. (2002, p. 21), 
who found that sediment production in the drainage areas supplying sand 
to Astragalus lentiginosus var. coachellae habitat is much lower in 
areas where the ground slope is less than 10 percent.
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in the ADDRESSES section. We request 
that you send comments only by the methods described in the ADDRESSES 
section. We will post your entire comment--including your personal 
identifying information--on https://www.regulations.gov. You may request 
at the top of your document that we withhold personal information such 
as your street address, phone number, or e-mail address from public 
review; however, we cannot guarantee that we will be able to do so.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on https://www.regulations.gov, or by 
appointment, during normal business hours, at the Carlsbad Fish and 
Wildlife Office (see FOR FURTHER INFORMATION CONTACT).

Background

    It is our intent to discuss only those topics directly relevant to 
the revised designation of critical habitat for Astragalus lentiginosus 
var. coachellae in this proposed rule. A summary of topics relevant to 
this proposed rule is provided below. For more information on A. l. 
var. coachellae, refer to the final listing rule published in the 
Federal Register on October 6, 1998 (63 FR 53596), and the designation 
of critical habitat for A. l. var. coachellae published in the Federal 
Register on December 14, 2005 (70 FR 74112). Additionally, information 
on this taxon may be found in the 5-year review for A. l. var. 
coachellae signed on September 1, 2009, which is available on our Web 
site at: https://www.fws.gov/carlsbad/.

Description of the Taxon

    Astragalus lentiginosus var. coachellae is a member of the Fabaceae 
(pea family). It is one of the 36 varieties of Astragalus lentiginosus 
that collectively range from desert to timberline in North America 
(Barneby 1964, pp. 911-958). Coachella Valley milk-vetch was originally 
described by Rupert C. Barneby as A. l. var. coulteri based on a 
specimen collected in 1913 by Alice Eastwood in Palm Springs, 
California (Barneby 1945, p. 129). However, the name had previously 
been published for another milk-vetch, and consequently Barneby 
published a new, and currently accepted, name of A. l. var. coachellae 
(Barneby 1964, p. 695). It is an erect winter annual or short-lived 
perennial, 4 to 12 inches (in) (10 to 30 centimeters (cm)) tall and 
densely covered with short, white-silky hairs, giving it a silvery 
appearance. The flowers are deep purple to violet, in a loose or dense 
13- to 25-flowered raceme (an inflorescence in which stalked flowers 
are arranged singly along a central stem). The two-chambered fruits are 
greatly inflated (Spellenberg 1993, pp. 597-598).

Taxon Biology and Life History

    Astragalus lentiginosus var. coachellae cohorts (a group of 
individuals of the same age, recruited into the population at the same 
time (Lincoln et al. 2003, p. 64)) may have different life histories, 
depending on rainfall and climatic conditions. Occurrences of plants 
can consist of both reproductive annuals as well as perennials 
(facultative perennial), and the number of individuals in an area can 
fluctuate yearly (Meinke et al. 2007, p. 6). Astragalus lentiginosus 
var. coachellae seeds germinate between fall and early winter (Meinke 
et al. 2007, p. 46). Seasonally dormant root crowns (the point at which 
the root system and stem of a plant meet) of perennial plants produce 
new shoots between December and January. Second-year plants can begin 
to flower as early as December, while plants in their first year 
usually do not flower until January or February. Flowering continues 
into April (Meinke et al. 2007, p. 6).
    Astragalus lentiginosus var. coachellae is an outcrosser (a plant 
that typically cross-pollinates) and is dependent on pollinators. While 
there are studies that show the plant is able to self-pollinate and 
generate viable seeds, A. l. var. coachellae is only marginally 
reproductively successful without pollinators and produces seed at very 
low rates. Meinke et al. (2007, p. 36) performed a pollinator exclusion 
study and found that only 2 fruits containing 11 seeds total were 
produced from 144 flowers limited to self-pollination, compared to 72 
fruits containing 596 seeds total produced by 138 flowers left open to 
insect pollination. Additionally, Mazer and Travers (1992) found that a 
related variety, A. l. var. piscinensis, is incapable of autogamy 
(self-fertilization) and reliant on pollinators. The presence of 
pollinators vastly improves the success of pollination and the 
abundance of seed produced by A. l. var. coachellae plants (Meinke et 
al. 2007, p. 36).
    Based on field observations, the primary pollinators of Astragalus 
lentiginosus var. coachellae in many instances appear to be nonnative 
honeybees (Apis mellifera) (Meinke et al. 2007, p. 36). Meinke et al. 
(2007, p. 36) observed that less than 1 percent of pollinator visits to 
A. l. var. coachellae plants were made by native bees (not identified; 
possibly a species of Anthidium); all other pollinator visits were made 
by nonnative honeybees. We presume the natural pollinator(s) of A. l. 
var. coachellae are native insects, most likely native solitary bees, 
because other varieties of Astragalus lentiginosus are known to have 
solitary bees as their major or essential pollinators (Burks 1979, p. 
850; Mazer and Travers 1992, p. 18).
    Fruits of Astragalus lentiginosus var. coachellae are inflated 
(contain pockets of air as opposed to being flat or compact); this 
adaptation makes the fruits suited to dispersal by wind when dry 
(Meinke et al. 2007, p. 40), which facilitates gene flow between 
populations. Insect predation, disease, and mammal herbivory destroy 
many seeds, leaving the viable seed set as only about 25 percent of the 
total number of fruits produced (Meinke et al. 2007, p. 43). As summer 
progresses and seed is set, the plants may die or aerial stems may die 
back. Plants may persist through the fall as dormant root crowns 
(Meinke et al. 2007, p. 6).
    Meinke et al. (2007, p. 31) observed that the proportion of plants 
surviving the summer and fall is dependent upon climatic conditions. 
Although they survive a second year, Astragalus lentiginosus var. 
coachellae are generally not long-lived (Meinke et al. 2007, p. 33). 
Plants in the northwestern portion of the range, where rainfall is 
higher, are more likely than those farther southeast to survive into 
their second year or longer. Plants that occur in the southeastern 
extent of the range, which receives less rain, are primarily annuals 
(Meinke et al. 2007, p. 31).
    Astragalus lentiginosus var. coachellae populations can survive and 
persist in prolonged drought as dormant seeds in the soil (seed bank) 
(Sanders and Thomas Olsen Associates 1996, p. 3). Therefore, visible, 
above-ground plants, which may not be evident at a site each year, are 
only a partial indication of population size. The

[[Page 53226]]

extent of time that the seeds are viable in the soil is not known, 
although studies on A. l. var. micans (freckled milk-vetch) demonstrate 
that buried seeds can germinate after a period of up to 8 years (Pavlik 
1987, p. 317). Suitable habitat that lacks above-ground individuals may 
sustain the taxon through one or more dry years as an undetectable seed 
bank and dormant root crowns. Therefore, appropriate habitat that lacks 
above-ground individuals may be important to the long-term survival of 
A. l. var. coachellae.

Habitat

    Astragalus lentiginosus var. coachellae is strongly associated with 
active, stabilized, ephemeral, and shielded sandy substrates in the 
Coachella Valley, Riverside County, California (Sanders and Thomas 
Olsen Associates 1996, p. 3; Barrows and Allen 2007, p. 323). This 
taxon is primarily found on loose aeolian (wind transported) or fluvial 
(water transported) sands that form dunes or sand fields, and along 
margins of sandy washes (Sanders and Thomas Olsen Associates 1996, p. 
3).
    Most of the sand in the northern Coachella Valley is derived from 
drainages within the Indio Hills, the San Bernardino Mountains, the 
Little San Bernardino Mountains, and the San Jacinto Mountains. This 
sand is moved into and through the valley by the sand transport system. 
The sand transport system consists of two main parts: (1) The fluvial 
(water) portion (headwaters, tributaries, and the stream channels 
within the various drainages surrounding Coachella Valley), and (2) the 
aeolian (wind) portion (predominantly westerly and northwesterly winds 
moving through the valley) (Griffiths et al. 2002, pp. 5-7). The 
fluvial and aeolian portions of the systems are capable of moving sand 
until the velocity of the water or wind decreases to a point that sand 
is deposited. Both portions of the system are subdivided into three 
components: source areas, transport areas, and depositional areas.
Fluvial Portion of the Sand Transport System
    The water that forms the basis of the fluvial portion of the sand 
transport system in the Coachella Valley enters the system as 
precipitation during storm events (Griffiths et al. 2002, p. 5). These 
storm events cause flash flooding, which facilitates the erosion that 
generates sediment, and moves that sediment downstream in ephemeral 
streams and washes and eventually into the aeolian transport corridor. 
Most flooding events only transport small amounts of sediment to the 
valley floor; flooding events large enough to move large amounts of 
sediment are very infrequent (for example, the last large flooding 
event on the Whitewater River occurred in 1938) (Griffiths et al. 2002, 
p. 5).
Fluvial Sand Source Areas
    Fluvial source areas are the areas where sediment is generated. In 
these areas, sediment is eroded from parent rock or sediment deposits 
and is carried downstream by moving water, which continues to erode 
rock and generate sediment until it reaches the fluvial transport area. 
This process occurs mainly in the hills and mountains surrounding 
Coachella Valley in areas of high relief (greater than 10 percent 
slope). However, in the Indio Hills/Thousand Palms area (which contains 
proposed Unit 4 of critical habitat, as described in the Proposed 
Critical Habitat Designation section below), the fluvial source area 
consists of alluvial deposits (sand, silt, clay, gravel, or other 
matter deposited by flowing water) at the base of the Indio Hills. 
Large episodic floods move sediment trapped in the alluvial deposits 
into an alluvial fan (a fan-shaped alluvial deposit formed by a stream 
where its velocity is abruptly decreased), from which the sediment can 
be transported by wind (Lancaster et al. 1993, p. 28). Fluvial sand 
source areas do not provide habitat for Astragalus lentiginosus var. 
coachellae and therefore are not considered to be within the 
geographical area occupied by the taxon at the time of listing.
Fluvial Sand Transport Areas
    The fluvial transport areas are stream channels that convey the 
sediment generated in fluvial source areas downstream to fluvial 
depositional areas. Very little erosion of parent rock or sediment 
deposits takes place in fluvial transport areas compared to fluvial 
source areas. Fluvial sand transport areas are generally portions of 
drainages where the slope is less than 10 percent. Fluvial transport 
channels include portions of the lower reaches of Mission Creek, 
Morongo Wash, Whitewater River, San Gorgonio River, and Snow Creek 
(upstream portions of these waterways are considered fluvial source 
areas because the higher ground slope in these areas allows for 
erosion/generation of sediment). Fluvial sand transport areas do not 
provide habitat for Astragalus lentiginosus var. coachellae and 
therefore are not considered to be within the geographical area 
occupied by the taxon at the time of listing.
Fluvial Sand Depositional Areas
    The fluvial sand depositional areas are broad, flat, depositional 
plains or channel terraces where sediment carried by fluvial transport 
channels is deposited (Griffiths et al. 2002, p. 5). During larger 
flood events, sediment can be deposited on bajada (large, coalescing 
alluvial fans) surfaces as floodplain deposits. There are four main 
fluvial sand depositional areas in the Coachella Valley: (1) In the 
Snow Creek/Windy Point area, which receives sediment from the San 
Gorgonio River and Snow Creek; (2) in the Whitewater Floodplain area, 
which receives sediment from the Whitewater River; (3) in the Willow 
Hole area, which receives sediment from Mission Creek and Morongo Wash; 
and (4) in the Thousand Palms area, which receives sediment from washes 
associated with drainages originating in the Indio Hills. These four 
main fluvial sand depositional areas do provide habitat for Astragalus 
lentiginosus var. coachellae, are currently occupied, and were occupied 
by the taxon at the time of listing.
Aeolian Portion of the Sand Transport System
    The aeolian portion of the sand transport system begins where the 
fluvial portion of the system ends. Northerly and northwesterly winds 
pick up sand-sized grains of sediment accumulated in fluvial 
depositional areas, and carry them south/southeast through the valley 
and into aeolian depositional areas where they form sand fields and 
dunes (Griffiths et al. 2002, p. 7).
Aeolian Sand Source Areas
    Aeolian sand source areas are the portions of the fluvial 
depositional areas that are subject to wind erosion. Winds erode these 
sediment accumulations and carry sand across aeolian sand transport 
areas. Between flooding events, which replenish the sediment in fluvial 
depositional areas, sand available for aeolian transport can be 
depleted by wind erosion. Figure 6B in Griffiths et al. (2002, p. 25) 
shows the aeolian sand source areas (fluvial depositional areas) 
associated with the San Gorgonio River, the Whitewater River, and 
Mission Creek and Morongo Wash. Aeolian sand source areas provide 
habitat for Astragalus lentiginosus var. coachellae, are currently 
occupied, and were occupied by the taxon at the time of listing.

[[Page 53227]]

Aeolian Sand Transport Areas
    Sand eroded from the aeolian sand source areas is blown into and 
across the aeolian sand transport areas. Sand may accumulate in aeolian 
transport areas when ample sand is available in upwind source areas; 
conversely, aeolian transport areas may be depleted of sand when sand 
is lacking upwind. Figure 6B in Griffiths et al. (2002, p. 25) shows 
the aeolian sand transport areas for the portions of the sand transport 
system associated with the San Gorgonio River, the Whitewater River, 
and Mission Creek and Morongo Wash. Aeolian sand transport areas 
provide habitat for Astragalus lentiginosus var. coachellae, are 
currently occupied, and were occupied by the taxon at the time of 
listing.
Aeolian Sand Depositional Areas
    Sand carried by wind through the sand transport areas is deposited 
when the velocity of the wind decreases sufficiently. This occurs 
mainly where wind is slowed by vegetation (for example, honey mesquite 
in the Willow Hole area), other objects, or geological features. In 
general, sand formations (for example, sand dunes and sand fields) 
persist in depositional areas, whereas sand accumulations in transport 
areas are more ephemeral. Aeolian sand depositional areas provide 
habitat for Astragalus lentiginosus var. coachellae, and support, 
currently and at the time of listing, the highest numbers of the taxon.
    The fluvial and aeolian processes discussed above have been 
disrupted in many areas by development, alteration of stream flow, and 
the proliferation of nonnative plants. These threats to the persistence 
of Astragalus lentiginosus var. coachellae habitat are discussed 
further in the Special Management Considerations or Protection section 
below.
Sand Formations
    Sand is found in various types of formations within the Coachella 
Valley, including but not limited to: Active sand dunes, stabilized or 
partially stabilized dunes, active sand fields, stabilized sand fields, 
shielded sand dunes and fields, ephemeral sand fields, and alluvial 
sand deposits on floodplain terraces of active washes. Each of these 
sand deposit formations provides habitat for Astragalus lentiginosus 
var. coachellae to varying degrees. A discussion of threats that are 
degrading the quality of A. l. var. coachellae habitat by impacting 
these sand formations (for example, development, unauthorized off-
highway vehicle use, nonnative plants, and groundwater pumping) is 
included below in the Special Management Considerations or Protection 
section.
Active and Stabilized or Partially Stabilized Sand Dunes
    Active sand dunes are almost barren expanses of moving sand with 
sparse, if any, perennial shrub cover. For Astragalus lentiginosus var. 
coachellae, active sand dunes provide suitable habitat. Active sand 
dunes may intermix with stabilized or partially stabilized dunes or 
become stabilized over time; stabilized sand dunes have similar sand 
accumulations and formations but are stabilized by shrubs, scattered 
low annuals, and perennial grasses. Stabilized or partially stabilized 
dunes are less vulnerable to loss of sand due to wind and therefore 
provide more stable habitat for long-term A. l. var. coachellae 
persistence (Griffiths et al. 2002, pp. 6-8).
Active Sand Fields
    Astragalus lentiginosus var. coachellae also occurs in active sand 
fields that are similar to active sand dunes, but are smaller, 
shallower sand accumulations of insufficient depth to form dunes. Sand 
fields may form hummocks, which are local accumulations of sand that 
form when sand accumulates around, and is held in place by, shrubs or 
clumps of vegetation (for example, Prosopis spp.-mesquite hummocks). 
Shrubs that form hummocks are important for the maintenance of A. l. 
var. coachellae habitat where the plants occur because they prevent 
sand from being removed from depositional areas faster than it can be 
replaced by natural sand transport processes. In areas where mesquite 
plants are being lost (such as Willow Hole and Thousand Palms), aeolian 
processes are removing sand faster than it can be replenished (see the 
Special Management Considerations or Protection section below for 
further discussion of loss of mesquite hummocks due to groundwater 
pumping).
Stabilized Sand Fields
    Stabilized sand fields are similar to active sand fields but 
contain sand accumulations that are stabilized by vegetation or are 
armored, a process where the wind picks up and moves smaller particles 
and leaves behind larger grains and gravels, forming an ``armor'' that 
prevents wind from moving additional smaller particles trapped below 
(Sharp and Saunders 1978, p. 12). Armored sand fields are temporarily 
stable, becoming active when the armor is disturbed over large areas 
(such as by flood, severe wind events, or human activities), or new 
sand is deposited from upwind fluvial depositional areas (Sharp and 
Saunders 1978, p. 12).
Shielded Sand Dunes and Fields
    Shielded sand dunes and fields are similar to the sand formations 
described above, except that sand source and transport systems that 
would normally replenish these areas have been interrupted or the dunes 
are otherwise shielded by human development (CVAG 2007, p. 4.7-5). 
These shielded areas support large occurrences of Astragalus 
lentiginosus var. coachellae that may contribute to the conservation of 
the taxon; however, the natural processes sustaining the habitat have 
been permanently removed.
Ephemeral Sand Fields
    Astragalus lentiginosus var. coachellae also occurs in ephemeral 
sand fields, which occur in areas where the rate at which sand is 
transported out of the area by wind exceeds the rate at which sand is 
replenished by upwind flood deposition events, resulting in a transient 
aeolian sand habitat that pulses after significant flood events deliver 
new sand to the aeolian transport corridor (Barrows and Allen 2007, p. 
323; USFWS GIS data). This type of formation generally occurs at the 
western end of the Coachella Valley, where wind velocities are the 
highest (Barrows and Allen 2007, p. 323).
Alluvial Fans or Flood Plains
    Astragalus lentiginosus var. coachellae can also occur on alluvial 
soils or on flood plain terraces (with little aeolian sands) in large 
alluvial fans, such as along Morongo Wash in Desert Hot Springs (J. 
Avery, USFWS Biologist, pers. obs. 2004-2009). Some of these formations 
have moderate amounts of diffuse disturbances and still support A. l. 
var. coachellae (Meinke et al. 2007, p. 21). Although the taxon can 
tolerate low levels of disturbance, plants do not typically persist 
into their second year in these conditions. Additionally, Meinke et al. 
(2007, p. 63) found that low levels of disturbance may help to promote 
seed germination. Therefore, the early stages and first-year plants of 
A. l. var. coachellae may be capable of surviving low-level 
disturbances that occur in these formations (Meinke et al. 2007, p. 
63).
    Suitable habitat may be transitory, and consequently currently 
unoccupied areas may become suitable following fluvial or aeolian 
events, and vice versa

[[Page 53228]]

(Lancaster 1995, p. 231). Conservation of the variety of sandy 
substrate types that may support the taxon is important for the 
conservation of Astragalus lentiginosus var. coachellae because of the 
dynamics of the aeolian sand transport processes. The life history of 
A. l. var. coachellae is uniquely suited to the transitory nature of 
its habitat, and the occurrences of the taxon will likely be impacted 
to the extent that the fluvial or aeolian sand transport systems are 
disrupted.
Plant Associations
    Astragalus lentiginosus var. coachellae commonly occurs in 
association with Desert Dunes or Creosote bush--white burr sage-scrub 
vegetation (Sawyer et al. 2009, pp. 566-569, 876-877). These vegetation 
types are associated with rainfall patterns, shifting from west to east 
across the Coachella Valley. The vegetation generally consists of 
dispersed perennial shrubs, with intervening shrubless tracts providing 
space for wind dispersal of A. l. var. coachellae fruits.
    Woody perennials, such as Lepidospartum squamatum (California 
broomsage), Hymenocela salsola (cheesebush), Ambrosia dumosa 
(burrobush), and Psorothamnus arborescens (California dalea) are 
typically associated with Astragalus lentiginosus var. coachellae in 
the western and relatively high-rainfall areas near the San Gorgonio 
Pass (Meinke et al. 2007, p. 21). These perennial taxa along with 
Larrea tridentata (creosote bush) and annuals such as Rafinesquia 
neomexicana (California chicory) and Camissonia pallida (pale sun cup) 
are characteristic of the sandy wash habitat at Snow Creek (Meinke et 
al. 2007, pp. 22-24). This habitat type is associated with the fluvial 
sand deposits on floodplain terraces (discussed above).
    In the southeastern extent of the range, where rainfall is the 
lowest, Astragalus lentiginosus var. coachellae occurs with annuals 
such as Abronia villosa (desert sand verbena), Oenothera deltoides 
(dune primrose), Geraea canescens (desert sunflower), Oligomeris 
linifolia (leaved cambess), Astragalus aridis (annual desert milk-
vetch), and Baileya pauciradiata (Colorado Desert marigold) (Meinke et 
al. 2007, p. 21) on primary dunes at the Coachella Valley National 
Wildlife Refuge (Meinke et al. 2007, p. 17). This habitat type is 
associated with active sand dunes or partially stabilized sand dunes 
(discussed above). Astragalus lentiginosus var. coachellae is variously 
found with Larrea tridentata (creosote bush), Psorothamnus emoryi 
(Emory dalea), Atriplex canescens (fourwing saltbush), Dicoria 
canescens (desert dicoria), Achnatherum (as Oryzopsis) hymenoides 
(Indian ricegrass), Croton californicus (California croton), and 
Petalonyx thurberi (sandpaper plant) on low-shifting dunes; sand 
fields; and small, isolated dunes (Meinke et al. 2007, pp. 22-24).
    Salsola tragus (Russian thistle), Schismus barbatus (Mediterranean 
grass), Tamarix spp. (salt-cedar), and Brassica tournefortii (Sahara 
mustard) are nonnative plants known to occur with and threaten 
Astragalus lentiginosus var. coachellae via competition for resources 
such as water and nutrients (Meinke et al. 2007, p. 26). The latter is 
considered to pose the most serious threat by competitive exclusion and 
by restricting natural movement of sand (Meinke et al. 2007, p. 24). 
Further discussion of nonnative plants is presented in the Special 
Management Considerations or Protection section below.

Spatial Distribution, Historical Range, and Population Size

    Astragalus lentiginosus var. coachellae has a distribution limited 
to the Coachella Valley, Riverside County, in the southern California 
portion of the Colorado Desert. At the time of listing, the 
distribution of the taxon was equivalent to the historical geographic 
range of the taxon. The range of A. l. var. coachellae has remained 
effectively the same since the taxon was listed as endangered in 1998 
(63 FR 53596; October 6, 1998); however, the spatial distribution 
within that range has changed as development has eliminated 
occurrences. At the time of listing, there were an estimated 25 extant 
occurrences of A. l. var. coachellae, and the quantity of suitable 
habitat was considered to be decreasing due to continuing direct and 
indirect impacts associated with development (63 FR 53596; October 6, 
1998). Additional occurrences have been detected within the historical 
geographic range of the taxon since 1998; however, it is likely that 
these occurrences existed at the time of listing and we are aware of 
them now because of increased survey efforts. Throughout this rule we 
refer to all occurrences as ``occupied at the time of listing'' 
regardless of whether the areas were documented before or after the 
taxon was listed.
    The majority of verified historical and extant occurrences of 
Astragalus lentiginosus var. coachellae are found in the northern 
Coachella Valley, from just east of the community of Cabazon eastward 
to the dunes off Washington Street, in the city of Thousand Palms, 
north and west of the city of Indio, within approximately 3 miles (mi) 
(5 kilometers (km)) of Interstate 10 (Barrows 1987 (map); CNDDB 2011). 
Collections northeast of Desert Center in the Chuckwalla Valley, east 
of the Coachella Valley, were thought at the time of listing to 
represent disjunct occurrences of A. l. var. coachellae (63 FR 53598). 
However, these have since been determined to most likely be A. l. var. 
variabilis (Meinke et al. 2007, p. 1).
    Periodic surveys and observations indicate that the extent and 
success of germination events and surviving reproductive population 
sizes may differ widely from year to year, depending on climatic and 
environmental conditions (for example, Barrows 1987, pp. 1-2). 
Densities of standing plants can vary considerably among occurrences 
across the taxon's range in any given year. This makes meaningful 
assessment of total numbers of Astragalus lentiginosus var. coachellae 
plants (that is, population size) difficult. Additionally, as discussed 
above, the number of standing plants at any given time is only a 
partial indication of population size because seeds can persist in the 
ground (seed bank) for a number of years (Sanders and Thomas Olsen 
Associates 1996, p. 3). The number of individuals present may also be 
underestimated if surveys are conducted at a time or place where aerial 
stems have died back and broken off leaving the root crown, which could 
be overlooked. The historical abundance of A. l. var. coachellae plants 
is unknown (Sanders and Thomas Olsen Associates 1996, p. 3).

Previous Federal Actions

    The following section summarizes the previous Federal actions since 
Astragalus lentiginosus var. coachellae was listed as endangered on 
October 6, 1998 (63 FR 53596); please refer to this final listing rule 
for a discussion of Federal actions that occurred prior to the taxon's 
listing.
    At the time of listing, we determined that designation of critical 
habitat was ``not prudent'' (63 FR 53596). On November 15, 2001, the 
Center for Biological Diversity (CBD) and the California Native Plant 
Society (CNPS) filed a lawsuit against the Secretary of the Interior 
and the Service challenging our ``not prudent'' determinations for 
eight plant taxa, including Astragalus lentiginosus var. coachellae 
(Center for Biological Diversity, et al. v. Norton, case number 01-cv-
2101 (S.D. Cal.)). A second lawsuit asserting the same challenge was 
filed on November 21, 2001, by the Building Industry Legal

[[Page 53229]]

Defense Foundation (Building Industry Legal Defense Foundation v. 
Norton, case number 01-cv-2145 (S.D. Cal.)). The parties in both cases 
agreed to remand the critical habitat determinations for the eight 
plant taxa at issue to the Service for reconsideration. On July 1, 
2002, the Court directed us to reconsider our not prudent determination 
and if we determined that designation was prudent, submit to the 
Federal Register for publication a proposed critical habitat 
designation for A. l. var. coachellae by November 30, 2004, and to 
submit to the Federal Register for publication a final rule designating 
critical habitat by November 30, 2005. The proposed rule to designate 
critical habitat for A. l. var. coachellae published in the Federal 
Register on December 14, 2004 (69 FR 74468). The final rule designating 
critical habitat for A. l. var. coachellae published in the Federal 
Register on December 14, 2005 (70 FR 74112).
    The Center for Biological Diversity filed a lawsuit on January 14, 
2009, claiming the Service failed to designate adequate critical 
habitat for Astragalus lentiginosus var. coachellae (CBD v. Kempthorne, 
case number ED-cv-09-0091 VAP(AGRx) (C.D. Cal.)). In a settlement 
agreement dated November 14, 2009, we agreed to reconsider the critical 
habitat designation for A. l. var. coachellae. The settlement requires 
the Service to submit a proposed revised critical habitat designation 
for A. l. var. coachellae to the Federal Register by August 18, 2011, 
and submit a final revised critical habitat designation to the Federal 
Register by February 14, 2013.

Critical Habitat

Background

    Critical habitat is defined in section 3 of the Act as:
    (1) The specific areas within the geographical area occupied by the 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features.
    (a) Essential to the conservation of the species and
    (b) Which may require special management considerations or 
protection; and
    (2) Specific areas outside the geographical area occupied by the 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    Conservation, as defined under section 3 of the Act, means to use 
and the use of all methods and procedures that are necessary to bring 
an endangered or threatened species to the point at which the measures 
provided pursuant to the Act are no longer necessary. Such methods and 
procedures include, but are not limited to, all activities associated 
with scientific resources management such as research, census, law 
enforcement, habitat acquisition and maintenance, propagation, live 
trapping, and transplantation, and, in the extraordinary case where 
population pressures within a given ecosystem cannot be otherwise 
relieved, may include regulated taking.
    Critical habitat receives protection under section 7 of the Act 
through the requirement that Federal agencies ensure, in consultation 
with the Service, that any action they authorize, fund, or carry out is 
not likely to result in the destruction or adverse modification of 
critical habitat. The designation of critical habitat does not affect 
land ownership or establish a refuge, wilderness, reserve, preserve, or 
other conservation area. Such designation does not allow the government 
or public to access private lands. Such designation does not require 
implementation of restoration, recovery, or enhancement measures by 
non-Federal landowners. Where a landowner seeks or requests Federal 
agency funding or authorization for an action that may affect a listed 
species or critical habitat, the consultation requirements of section 
7(a)(2) would apply, but even in the event of a destruction or adverse 
modification finding, the obligation of the Federal action agency and 
the landowner is not to restore or recover the species, but to 
implement reasonable and prudent alternatives to avoid destruction or 
adverse modification of critical habitat.
    For inclusion in a critical habitat designation, the habitat within 
the geographical area occupied by the species at the time it was listed 
must contain physical or biological features which are essential to the 
conservation of the species and which may require special management 
considerations or protection. Critical habitat designations identify, 
to the extent known using the best scientific and commercial data 
available, those physical or biological features that are essential to 
the conservation of the species (such as space, food, cover, and 
protected habitat), focusing on the principal biological or physical 
constituent elements (primary constituent elements) within an area that 
are essential to the conservation of the species (such as roost sites, 
nesting grounds, seasonal wetlands, water quality, tide, soil type). 
Primary constituent elements are the elements of physical or biological 
features that, when laid out in the appropriate quantity and spatial 
arrangement to provide for a species' life-history processes, are 
essential to the conservation of the species.
    Under the Act, we can designate critical habitat in areas outside 
the geographical area occupied by the species at the time it is listed, 
upon a determination that such areas are essential for the conservation 
of the species. We designate critical habitat in areas outside the 
geographical area occupied by a species only when a designation limited 
to its range would be inadequate to ensure the conservation of the 
species. When the best available scientific data do not demonstrate 
that the conservation needs of the species require such additional 
areas, we will not designate critical habitat in areas outside the 
geographical area occupied by the species. An area currently occupied 
by the species but that was not occupied at the time of listing may, 
however, be essential for the conservation of the species and may be 
included in the critical habitat designation.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific and commercial data available. 
Further, our Policy on Information Standards Under the Endangered 
Species Act (published in the Federal Register on July 1, 1994 (59 FR 
34271)), the Information Quality Act (section 515 of the Treasury and 
General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658)), and our associated Information Quality 
Guidelines, provide criteria, establish procedures, and provide 
guidance to ensure that our decisions are based on the best scientific 
data available. They require our biologists, to the extent consistent 
with the Act and with the use of the best scientific data available, to 
use primary and original sources of information as the basis for 
recommendations to designate critical habitat.
    When we determine which areas should be designated as critical 
habitat, our primary source of information is generally the information 
developed during the listing process for the species. Additional 
information sources may include the recovery plan for the species, 
articles in peer-reviewed journals, conservation plans developed by 
States and counties, scientific status surveys and studies, biological 
assessments, or other unpublished materials and expert opinion or 
personal knowledge.

[[Page 53230]]

Climate Change and Critical Habitat
    ``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, 
precipitation, and wind, whereas ``climate change'' refers to a change 
in the mean or variability or both 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 America 
and South America, northern Europe, and northern and central Asia; 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 United States 
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; 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 IPPC for making projections (e.g., Raupach et al. 
2007, Figure 1, p. 10289; Pielke et al. 2008, entire; Manning et al. 
2010, Figure 1, p. 377). Also, the best scientific and commercial data 
available indicate 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). With regard to the area of analysis for 
Astragalus lentiginosus var. coachellae, downscaled projections are not 
available.
Critical Habitat Dynamics
    Habitat is dynamic, and species may move from one area to another 
over time. We recognize that critical habitat designated at a 
particular point in time may not include all of the habitat areas that 
we may later determine are necessary for the recovery of the species. 
For these reasons, a critical habitat designation does not signal that 
habitat outside the designated area is unimportant or may not be 
required for recovery of the species. Areas that are important to the 
conservation of the species, both inside and outside the critical 
habitat designation, will continue to be subject to: (1) Conservation 
actions implemented under section 7(a)(1) of the Act, (2) regulatory 
protections afforded by the requirement in section 7(a)(2) of the Act 
for Federal agencies to insure their actions are not likely to 
jeopardize the continued existence of any endangered or threatened 
species, and (3) the prohibitions of section 9 of the Act if actions 
occurring in these areas may affect the species. Federally funded or 
permitted projects affecting listed species outside their designated 
critical habitat areas may still result in jeopardy

[[Page 53231]]

findings in some cases. These protections and conservation tools will 
continue to contribute to recovery of this species. Similarly, critical 
habitat designations made on the basis of the best available 
information at the time of designation will not control the direction 
and substance of future recovery plans, habitat conservation plans 
(HCPs), or other species conservation planning efforts if new 
information available at the time of these planning efforts calls for a 
different outcome.

Physical or Biological Features

    In accordance with sections 3(5)(A)(i) and 4(b)(1)(A) of the Act 
and regulations at 50 CFR 424.12, in determining which areas within the 
geographical area occupied at the time of listing to propose as 
critical habitat, we consider the physical or biological features 
essential to the conservation of the species and which may require 
special management considerations or protection. These include, but are 
not limited to:
    (1) Space for individual and population growth and for normal 
behavior;
    (2) Food, water, air, light, minerals, or other nutritional or 
physiological requirements;
    (3) Cover or shelter;
    (4) Sites for breeding, reproduction, or rearing (or development) 
of offspring; and
    (5) Habitats that are protected from disturbance or are 
representative of the historical, geographical, and ecological 
distributions of a species.
    We derive the specific physical or biological features essential 
for Astragalus lentiginosus var. coachellae from studies of this 
taxon's habitat, ecology, and life history as described below. 
Additional information can be found in the final listing rule published 
in the Federal Register on October 6, 1998 (63 FR 53596), and the 5-
year review for A. l. var. coachellae signed on September 1, 2009 
(Service 2009). We have determined that the following physical and 
biological features are essential to A. l. var. coachellae:
Space for Individual and Population Growth and for Normal Behavior
    Astragalus lentiginosus var. coachellae has a limited distribution. 
Within its limited range, A. l. var. coachellae requires space for the 
natural fluvial and aeolian transport and deposition of the sandy 
substrates on which it grows. Protection of aeolian and fluvial 
processes is crucial to maintain habitat for A. l. var. coachellae. 
These processes are responsible for transporting and depositing sand 
that is the foundation of habitat for A. l. var. coachellae. 
Disturbance or curtailment of these processes can result in a lack of 
adequate amounts of sand to produce the different formations that 
support habitat (for example, active dunes and sand fields). Protecting 
aeolian sand transport corridors between A. l. var. coachellae 
occurrences is also important for the dispersal of the wind-blown 
fruits into temporally unoccupied habitat to reestablish reproductive 
occurrences (metapopulation structure). Astragalus lentiginosus var. 
coachellae is also dependent upon insect pollinators (Meinke et al. 
2007, p. 37). Protecting aeolian sand transport corridors also provides 
space for pollinator movement between occurrences, which is important 
for the long-term maintenance of occurrences. Therefore, based on the 
information above, we identify fluvial and aeolian sand transport and 
deposition processes, and aeolian sand transport corridors for seed 
dispersal and pollinator movement, to be physical or biological 
features for this taxon.
Food, Water, Air, Light, Minerals, or Other Nutritional or 
Physiological Requirements
    Astragalus lentiginosus var. coachellae is primarily found on 
various types of sand formations including active sand dunes, 
stabilized or partially stabilized dunes, active sand fields, 
stabilized sand fields, shielded sand dunes and fields, ephemeral sand 
fields, and alluvial sand deposits on floodplain terraces of active 
washes. Each of these sand deposit formations provides habitat for A. 
l. var. coachellae to varying degrees (see Habitat section above for 
further discussion of sand formations that support the taxon). The 
taxon also requires moving water and air to transport sand from sand 
source areas to occupied habitat areas as discussed above. Astragalus 
lentiginosus var. coachellae can be found in abundance on shielded sand 
fields, and the A. l. var. coachellae plants in these areas are 
important for the conservation of the taxon. However, we do not 
consider shielded habitat to contain the physical or biological 
features essential to the conservation of the taxon, because these 
areas are permanently cut off from the sand transport system. Shielded 
areas, although they currently contain sand formations, will eventually 
lose these formations as the winds remove sand over time. Therefore, 
based on the information above, we identify the other above-mentioned 
sand formations to be a physical or biological feature for this taxon.
    The physiological and soil nutritional needs of Astragalus 
lentiginosus var. coachellae are not known at this time. The taxon 
shows variation in productivity and life-history patterns that appear 
to coincide with local or temporal variations in precipitation (wetter 
years result in higher levels of seed germination (e.g., Barrows 1987, 
p. 2)) and across its range (plants in the northwestern portion of the 
range where rainfall is higher are more likely to grow larger and 
survive into their second year or longer (Meinke et al. 2007, p. 25)). 
However, the specific optimal soil moisture range for the taxon is 
unknown.
    Additionally, the taxon does not grow in some areas that appear to 
contain suitable habitat. For example, Astragalus lentiginosus var. 
coachellae grows on some portions of the alluvial sand deposits on 
floodplain terraces of Morongo Wash, but not others, and it does not 
grow in the bed of the wash when the bed is dry even though the bed 
contains sandy substrates (J. Avery, USFWS Biologist, pers. obs. 2004-
2009). These apparent inconsistencies may be due to microsite 
differences (such as nutrient availability, soil microflora or 
microfauna, soil texture, or moisture). Research is needed to determine 
the specific nutritional and physiological requirements of A. l. var. 
coachellae.
Sites for Reproduction
    Astragalus lentiginosus var. coachellae plants, like most plants, 
do not require areas for breeding or reproduction other than the areas 
they occupy and any area necessary for pollinators and seed dispersal. 
Reproduction sites accommodate all phases of the plant's life history. 
Seeds likely require certain soil conditions to germinate (for example, 
moisture and nutrient levels within a certain range, or close proximity 
to the soil surface), but as discussed above, we do not yet know what 
those requirements are. In addition, wind is important for the 
dispersal of the wind-blown fruits into temporally unoccupied habitat 
(metapopulation structure) of A. l. var. coachellae.
    The primary visitors of Astragalus lentiginosus var. coachellae 
appear to be nonnative honeybees (Apis mellifera) (Meinke et al. 2007, 
p. 36). These bees appear to be flexible in their choice of nesting 
sites. For example, bee nests were found in discarded tires, in Tamarix 
spp. trees, and under a bridge near A. l. var. coachellae occurrences 
(Meinke et al. 2007, p. 36).

[[Page 53232]]

    Native solitary bees, which may be the natural pollinators of 
Astragalus lentiginosus var. coachellae, utilize several plant species 
as pollen and nectar sources (Karron 1987, p. 188). Maintaining 
adequate populations of these bees likely depends on the presence of a 
variety of native plant species in sufficient numbers within or near A. 
l. var. coachellae occurrences, as well as between A. l. var. 
coachellae occurrences, to facilitate gene flow between occurrences. We 
do not know, however, why native bees have not yet been observed 
pollinating A. l. var. coachellae. Until specific pollinators for A. l. 
var. coachellae are identified, we are unable to consider protection of 
their specific habitat explicitly via this critical habitat 
designation. Therefore, based on the information above, we identify 
aeolian sand transport corridors for seed dispersal and pollinator 
movement to be a physical or biological feature for this taxon.
Habitats Protected From Disturbance or Representative of the 
Historical, Geographical, and Ecological Distributions of the Taxon
    Astragalus lentiginosus var. coachellae is primarily found on loose 
aeolian (wind-transported) or fluvial (water-transported) sands that 
are located on dunes or sand fields, and along disturbed margins of 
sandy washes. Within active, stabilized, and ephemeral sand fields and 
dunes, A. l. var. coachellae tends to occur in coarse sands in the 
margins of dunes, but not in most active windswept sand areas 
(Coachella Valley MSHCP/NCCP 2007, pp. 9-27) (see Habitat section above 
for more detailed description of active and stabilized sand fields and 
dunes). Therefore, based on the information above, we identify 
substrate components and conditions suitable to support A. l. var. 
coachellae to be a physical or biological feature for this taxon.
    The sandy substrates that are suitable for Astragalus lentiginosus 
var. coachellae are dynamic in terms of spatial mobility and tendency 
to change back and forth from active to stabilized (Lancaster 1995, p. 
231). This has significant consequences for A. l. var. coachellae 
because the plant's population densities vary with different types of 
sandy substrates. Conserving the dynamics of the fluvial and aeolian 
sand transport processes is important for the conservation of A. l. 
var. coachellae because those dynamics create a variety of substrate 
types that support occurrences of the taxon.
    The dynamics of the sandy substrates in the Coachella Valley are 
controlled by two main factors: (1) The supply of sand-sized sediment 
released, transported, and deposited by the fluvial system (water-
transported); and (2) the rate of aeolian (wind-blown) transport 
(Griffiths et al. 2002, pp. 4-8). The latter is affected primarily by 
wind fetch (the length of unobstructed area exposed to the wind).
    Most of the suitable sandy habitats in the Coachella Valley are 
generated from several drainage basins in the San Bernardino, Little 
San Bernardino, and San Jacinto Mountains and Indio Hills (Lancaster et 
al. 1993, pp. i-ii; Griffiths et al. 2002, p. 10). Sediment is eroded 
and washed from fluvial source areas (hill slopes and channels in the 
local hills and alluvial deposition areas in the Thousand Palms area 
(Unit 4)), and is transported downstream in stream channels and within 
alluvial fans during infrequent flood events (Griffiths et al. 2002, p. 
7). Fluvial transport is the dominant mechanism that moves sediment 
into fluvial depositional areas in the Coachella Valley (Griffiths et 
al. 2002, p. 7). The largest depositional area in the Coachella Valley 
is in the Whitewater River floodplain, northwest of the City of Palm 
Springs (Griffiths et al. 2002, p. 5). For sufficient fine-grained 
sands to reach the aeolian system on the valley floor and support 
Astragalus lentiginosus var. coachellae, it is necessary to protect 
major fluvial channels that transport source sand from the surrounding 
drainage basins as well as bajadas and depositional areas. The 
Coachella Valley MSHCP/NCCP identifies the protection of the above-
mentioned essential ecological processes, including sand source/
transport systems, as a species conservation goal.
    The San Gorgonio Pass is between the two highest peaks in southern 
California: San Gorgonio Mountain (11,510 feet (ft) (3,508 meters (m))) 
to the north and San Jacinto Mountain (10,837 ft (3,303 m)) to the 
south. Westerly winds funneling through San Gorgonio Pass are the 
dominant mechanism by which aeolian sands are transported from bajadas 
and fluvial depositional areas to aeolian deposits in the Coachella 
Valley (Sharp and Saunders 1978, p. 12; Griffiths et al. 2002, p. 1). 
Astragalus lentiginosus var. coachellae is associated with various 
types of sand formations that are formed by these aeolian deposits 
(Sanders and Thomas Olsen Associates 1996, p. 3). In order to maintain 
adequate replenishment of sands into aeolian depositional areas, it is 
important that sand-transport corridors be