Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Arenaria ursina, 73092-73178 [07-6137]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 72, Number 246 (Wednesday, December 26, 2007)]
[Rules and Regulations]
[Pages 73092-73178]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 07-6137]



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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 Arenaria ursina (Bear Valley Sandwort), Castilleja cinerea 
(Ash-gray Indian Paintbrush), and Eriogonum kennedyi var. 
austromontanum (Southern Mountain Wild-Buckwheat); Final Rule

Federal Register / Vol. 72, No. 246 / Wednesday, December 26, 2007 / 
Rules and Regulations

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AU80


Endangered and Threatened Wildlife and Plants; Designation of 
Critical Habitat for Arenaria ursina (Bear Valley Sandwort), Castilleja 
cinerea (Ash-gray Indian Paintbrush), and Eriogonum kennedyi var. 
austromontanum (Southern Mountain Wild-Buckwheat)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are 
designating critical habitat for Arenaria ursina (Bear Valley 
sandwort), Castilleja cinerea (Ash-gray Indian paintbrush), and 
Eriogonum kennedyi var. austromontanum (southern mountain wild-
buckwheat) under the Endangered Species Act of 1973, as amended (Act). 
In total, approximately 1,769 acres (ac) (722 hectares (ha)) of land 
fall within the boundaries of the critical habitat designations for 
these three species. Approximately 1,412 ac (571 ha) of Federal and 
private land are being designated as critical habitat for Arenaria 
ursina; approximately 1,769 ac (722 ha) of Federal, State, and private 
land are being designated as critical habitat for Castilleja cinerea; 
and approximately 904 ac (366 ha) of Federal and private land are being 
designated as critical habitat for Eriogonum kennedyi var. 
austromontanum. All lands included in these final designations are in 
San Bernardino County, California. These final designations include an 
addition of a total of 258 ac (111 ha) from the total area included in 
the 2006 proposed designations for these species.

DATES: This rule becomes effective on January 25, 2008.

FOR FURTHER INFORMATION CONTACT: Jim Bartel, Field Supervisor, Carlsbad 
Fish and Wildlife Office, at 6010 Hidden Valley Road, Carlsbad, CA 
92011 (telephone 760/431-9440). Persons who use a telecommunications 
device for the deaf (TDD) may call the Federal Information Relay 
Service (FIRS) at 800-877-8339, 24 hours a day, 7 days a week. The 
final rule, economic analysis, and maps are available via the Internet 
at https://www.fws.gov/carlsbad/.

SUPPLEMENTARY INFORMATION:

Background

    It is our intent to reiterate and discuss only those topics 
directly relevant to the development and designation of critical 
habitat or relevant information obtained since publication of the 
proposed critical habitat designations (71 FR 67712; November 22, 
2006). This final rule addresses critical habitat for Arenaria ursina 
(Bear Valley sandwort), Castilleja cinerea (Ash-gray Indian 
paintbrush), and Eriogonum kennedyi var. austromontanum (southern 
mountain wild-buckwheat) (collectively referred to as ``pebble plains 
plants''), because they largely occupy the same habitat, referred to as 
pebble plain habitat. For additional information on the taxonomy, 
description, biology, and ecology of each of these species, refer to 
the final rule listing them as threatened published in the Federal 
Register on September 14, 1998 (63 FR 49006) or the proposed critical 
habitat rule published in the Federal Register on November 22, 2006 (71 
FR 67712).

Pebble Plain Habitat

    No new substantial information pertaining to the ``Pebble Plain 
Habitat'' section in the proposed designation was received following 
publication of the 2006 proposed critical habitat designation for each 
species; therefore, please refer to the ``Background'' section of the 
proposed critical habitat designation published in the Federal Register 
on November 22, 2006 (71 FR 67712) for a discussion of pebble plain 
habitat.

Species Descriptions

    No new substantial information pertaining to the ``Species 
Descriptions'' section in the proposed designation was received 
following our 2006 proposed critical habitat designation for each 
species; therefore, please refer to the ``Background'' section of the 
proposed critical habitat designation published in the Federal Register 
on November 22, 2006 (71 FR 67712) for a discussion of the species 
description of these three species.

Threats to Pebble Plains Habitat

    No new substantial information pertaining to the ``Threats to 
Pebble Plains Habitat'' section in the proposed designation was 
received following the 2006 proposed critical habitat designation for 
each species; therefore, please refer to the ``Background'' section of 
the proposed critical habitat designation published in the Federal 
Register on November 22, 2006 (71 FR 67712) for a discussion of the 
threats to pebble plains habitat.

Previous Federal Actions

    As discussed in the November 22, 2006, proposed rule (71 FR 67712), 
the Service agreed, as part of a settlement agreement, to submit to the 
Federal Register a proposed rule to designate critical habitat, if 
prudent, on or before November 9, 2006, and a final rule by November 9, 
2007. We published a proposed critical habitat rule in the Federal 
Register on November 22, 2006 (71 FR 67712). We also published a notice 
of availability of the draft economic analysis of the November 22, 
2006, proposed rule in the Federal Register on August 14, 2007 (72 FR 
45407). This final rule completes our obligations under the April 14, 
2005, settlement agreement regarding the subject species. For a 
discussion of additional previous Federal actions involving these three 
pebble plains plants, please see the listing rule (63 FR 49006; 
September 14, 1998) or the proposed critical habitat rule (71 FR 67712; 
November 22, 2006).

Summary of Comments and Recommendations

    We requested comments from the public on the proposed designations 
of critical habitat for the pebble plains plants during two comment 
periods. The first comment period, associated with the publication of 
the proposed rule (71 FR 67712), opened on November 22, 2006, and 
closed on January 22, 2007. We did not receive any requests for a 
public hearing during this comment period. We also requested comments 
on the proposed rule and draft economic analysis (DEA) during a comment 
period that opened August 14, 2007 (72 FR 45407) and closed on 
September 13, 2007. We contacted appropriate Federal, State, and local 
agencies; scientific organizations; and other interested parties and 
invited them to comment on the proposed rule during these two comment 
periods.
    During the first comment period, we received five comment letters 
directly addressing the proposed critical habitat designations: three 
from peer reviewers, one from a Federal agency, and one from an 
organization. During the second comment period, we received no comment 
letters addressing the proposed critical habitat designations or the 
draft economic analysis. Comments received during both comment periods 
are addressed in the following summary and incorporated into the final 
rule as appropriate.

Peer Review

    In accordance with our policy published on July 1, 1994 (59 FR 
34270), we solicited expert opinions from four knowledgeable 
individuals with scientific expertise that included familiarity with 
the species, the

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geographic region in which the species occurs, and conservation biology 
principles. We received responses from three of the four peer reviewers 
we requested comment from. Peer reviewer comments are addressed in the 
following summary and incorporated into the final rule as appropriate.

Peer Reviewer Comments

    (1) Comment: One peer reviewer agreed with the proposed 
designations overall and stated that proposed critical habitat Units 1, 
3, 5, and 9 essentially contain all of the pebble plains habitat for 
the subject taxa in those areas. However, this reviewer cited other 
pebble plains habitat occupied by one or more of the listed species 
that were overlooked by the designations.
    Our Response: Many of the pebble plains listed by the peer reviewer 
as ``overlooked'' by the designations were also described (by the 
reviewer) as small, isolated pebble plains, within areas degraded by 
residential development. As discussed in the ``Criteria Used to 
Identify Critical Habitat'' section of the proposed rule, we worked 
closely with San Bernardino National Forest (SBNF) personnel with 
knowledge of pebble plains plants and habitats to identify critical 
habitat for each of the three listed pebble plains plants based on 
several criteria. Since the pebble plains identified by the reviewer 
and other pebble plains in these complexes were relatively small, 
isolated from other pebble plains, and/or degraded to some extent, they 
did not meet our criteria used to identify critical habitat for each 
species and therefore were not included in the proposed or these final 
designations (see ``Criteria Used To Identify Critical Habitat'' 
section below for a detailed discussion).
    (2) Comment: One peer reviewer commented that proposed critical 
habitat Subunit 3A in Broom Flat [ppn. 311; ppn. = pebble plain number 
as identified in the USFS Pebble Plain Management Guide (USFS 2002)] is 
mapped such that, except for a sliver of an adjacent pebble plain (ppn. 
274) supporting Arenaria ursina and Eriogonum kennedyi var. 
austromontanum, only Castilleja cinerea is captured.
    Our Response: We appreciate the correction pertaining to pebble 
plain number 311 in proposed critical habitat Subunit 3A. We recognize 
that the great majority of Subunit 3A is occupied solely by Castilleja 
cinerea and have revised this final rule such that this subunit (ppn. 
311) is designated as critical habitat only for C. cinerea, even though 
the other two listed plants occur in one small portion of this 
particular pebble plain (see ``Summary of Changes from the Proposed 
Rule'' and the ``Unit Descriptions'' sections below).
    (3) Comment: One peer reviewer commented that pebble plains 
occupied by Castilleja cinerea located west of Wildhorse Meadow Road in 
the Sugarloaf Ridge complex should have been included in the proposed 
designation for C. cinerea because these areas represent a significant 
and distinctive population of this species, with shorter, maroon 
bracts, as opposed to C. cinerea in Big Bear and Holcomb Valley, which 
have broader, yellow-gold bracts. Another peer reviewer stated that two 
of the pebble plains identified in the previous peer reviewer's comment 
(ppn. 286 and 293) along Sugarloaf Ridge west of Wildhorse Meadow not 
included in the proposed designations support large and relatively 
undisturbed occurrences of C. cinerea at the highest known elevation 
and that such elevational extremes may be important for the 
conservation of the species where they represent genetic variation 
favorable to surviving long term environmental changes.
    Our Response: We acknowledged in the proposed rule that the 
Sugarloaf Ridge complex contains occurrences of Castilleja cinerea that 
are morphologically distinct from occurrences in other complexes, and 
that these occurrences represent a unique portion of the range of 
environmental variability for these species and may be important for 
maintaining genetic diversity for the species. At the time of the 
proposed rule we believed that our proposal adequately represented the 
morphologically distinct form of C. cinerea within the Sugarloaf Ridge 
complex. Upon receipt of these peer reviewer comments, we reviewed the 
available information regarding the pebble plains in this area and 
determined that the two largest (of three) pebble plains west of 
Wildhorse Meadow Road Sugarloaf Ridge complex (ppn. 286 and 293) do, in 
fact, meet the definition of critical habitat for C. cinerea (see 
``Summary of Changes from the Proposed Rule'' and the ``Unit 
Descriptions'' sections below). Including these two pebble plains in 
this designation increases the representation, resiliency, and 
redundancy of this morphologically distinct form of the species and the 
unique portion of the range of environmental variability for C. 
cinerea. We have, therefore designated these two pebble plains as 
critical habitat for C. cinerea. Furthermore, as commented on by a 
separate peer reviewer these two pebble plains support large and 
relatively undisturbed occurrences of C. cinerea, one (ppn 293) at the 
highest known elevation occupied by this species.
    (4) Comment: One peer reviewer agreed with the description and 
characterization of each of the three listed pebble plains plants and 
their associated habitats. However, they suggested including Robinson, 
B.C. (1894) as the original description of Arenaria ursina. This 
reviewer also commented that proposed critical habitat Unit 3 (Gold 
Mountain) is described as being 88 acres (ac) (36 hectares (ha)) on 
page 67722 but 105 ac (42 ha) on page 67723 of the proposed rule.
    Our Response: We appreciate the additional information. We have 
included Robinson (1894) in our administrative file for the designation 
of critical habitat for Arenaria ursina. Regarding the difference in 
area estimates given for proposed critical habitat Unit 3, the 88 acres 
(36 ha) discussed on page 67722 pertains to an early estimate of pebble 
plain habitat in the Gold Mountain complex (USFS 2002, pp. 32, 52). 
However, as discussed on page 67723 of the proposed rule, we used only 
the most recent and accurate information (SBNF 2004 Geographic 
Information System (GIS)) to delineate proposed critical habitat 
boundaries which indicates Unit 3 is 105 ac (42 ha).
    (5) Comment: One peer reviewer provided additional information on 
threats, land-use designations, and why specific occurrences are 
essential to the conservation of the species for several pebble plains 
included in the proposed designations. This reviewer also stated that a 
well developed communication site on private land at Onyx Peak is 
within proposed Subunit 3B and that as a result, this area may lack the 
primary constituent elements (PCEs) required by the species.
    Our Response: We appreciate the additional information provided on 
threats, land-use designations, and why specific occurrences are 
essential to the conservation of the species and have included this 
information in this final rule (please see the ``Unit Descriptions'' 
section). Regarding the communication site located within proposed 
Subunit 3B, as stated in the proposed rule, we tried to avoid including 
within the boundaries of the proposed critical habitat developed areas 
such as buildings, paved areas, and other structures that lack PCEs for 
the three listed species. However, the scale of the maps prepared may 
not reflect the exclusion of such developed areas. Any such structures 
and the land under them inadvertently left inside critical habitat

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boundaries shown on the maps of the proposed rule are excluded by text 
in this rule and are not considered to be critical habitat.
    (6) Comment: One peer reviewer commented that the rule incorrectly 
states that Arenaria ursina and Castilleja cinerea were not known to 
occur at the time of listing on Sugarloaf Ridge. However, these 
occurrences have been known since the 1970's or earlier and fall within 
the following element occurrences in the California Natural Diversity 
Database (CNDDB) (A. ursina number 7 and C. cinerea numbers 4, 12, 13, 
and 14).
    Our Response: We appreciate the correction and have revised this 
statement accordingly in this final rule (see the ``Criteria Used To 
Identify Critical Habitat'' and ``Unit Descriptions'' sections below).
    (7) Comment: One peer reviewer suggested corrections and/or 
clarification of the following: (1) Our characterization of pebble 
plains habitat as ``dry meadow-like'' habitat, (2) references to 
Mojavean Desert scrub should be changed to Great Basin sagebrush, and 
(3) primary constituent element (PCE) 2 should be revised to clarify 
that the frost/heave process has more to do with excluding large/woody 
species from colonizing pebble plains than directly providing for the 
physiological requirements of the species.
    Our Response: We responded to these comments in the following ways: 
(1) we characterized pebble plain habitat as ``dry meadow-like'' 
habitat to provide an additional description of this habitat type and 
to assist the public in visualizing what habitat comprised of 
``treeless openings surrounded by woodland or forest'' looks like; (2) 
as noted by the reviewer, references to Mojavean Desert scrub in the 
proposed rule were based on the 2002 Pebble Plains Habitat Management 
Guide (Management Guide; USFS 2002). We have replaced references to 
this vegetation type throughout this final rule with ``Great Basin 
sagebrush'' as suggested; and (3) we revised the text of the PCE 
section and PCE 2 accordingly (see ``Primary Constituent Elements'' 
section below).
    (8) Comment: One peer reviewer commented that relative to threats 
to the species outlined in the proposed rule, habitat loss through 
private land development remains the main cause of continued decline of 
these species while unauthorized motorized vehicle travel off of 
designated system routes continues to be the primary cause of pebble 
plain habitat degradation on U.S. Forest Service's (USFS) lands. This 
reviewer further stated that forest system road use and maintenance, 
mining activities, and dispersed recreation continue to have adverse 
ongoing effects to pebble plain habitat and the species it supports. 
However, the magnitude and severity of effects caused by these 
activities are relatively small compared to the effects of unauthorized 
motorized vehicle use.
    Our Response: We appreciate the clarification and have revised the 
text of this final rule to emphasize that habitat loss is the primary 
threat to the three listed species on private land while unauthorized 
motorized vehicle travel off of designated system routes continues to 
be the primary threat to these species on Federal lands (see the 
``Special Management Considerations or Protection'' section below).
    (9) Comment: One peer reviewer commented that the proposed rule did 
not mention vegetation and fuels management, hazard tree removal, or 
wildfire suppression in the list of threats to pebble plains habitat. 
This reviewer commented that many pebble plains on USFS lands lie 
within the USFS Wildland-Urban Interface (WUI) defense zone and that 
unavoidable adverse impacts would be addressed through section 7 
consultation.
    Our Response: We appreciate the information and have included a 
discussion of vegetation and fuels management, hazard tree removal, and 
wildfire suppression activities as potential threats to these species' 
habitat in the WUI zone on USFS land in this final rule (see ``Special 
Management Considerations or Protection'' and ``Unit Descriptions'' 
sections below).
    (10) Comment: One peer reviewer commented that the ``Special 
Management Considerations or Protection'' section fails to address the 
potential impacts to these three species from global climate change. 
Also, the ``Special Management Considerations or Protection'' section 
does not identify whether and how critical habitat could provide for 
long-term conservation for these species if climate change were to 
occur. This reviewer further stated that one reason that critical 
habitat could be viewed as a benefit to species' conservation is that 
the 11 identified units represent a range of habitat conditions for 
these species which could allow them to persist at least at some of the 
sites should conditions change toward one end of the gradient.
    Our Response: We did not address the potential impacts of global 
climate change to these species in the proposed rule because we are not 
currently aware of any species-specific or geographic-specific 
information on this potential threat nor did the reviewer provide 
additional information on this threat regarding how it might impact 
these species or their habitat. However, as noted by the peer reviewer, 
we did include in the critical habitat designations pebble plain 
habitat representing a range of habitat conditions that could allow 
them to persist in the event of environmental change. For example, one 
of the criterions for areas proposed as critical habitat for Castilleja 
cinerea were areas containing unique habitat characteristics (see 
``Criteria Used to Identify Critical Habitat'' section of the proposed 
rule). While not specifically identified as a criterion for inclusion 
in the proposed designations, areas containing Arenaria ursina or 
Eriogonum kennedyi var. austromontanum occurrences at the extremes of 
the species' geographic range (e.g., northernmost extent) or elevation 
range (highest or lowest elevation) were included in the proposed 
designations. We have revised the text to more clearly state the 
importance of conserving habitat representing a range of conditions 
that could allow these species to persist in the event of environmental 
change (see ``Criteria Used to Identify Critical Habitat'' section 
below).
    (11) Comment: One peer reviewer and one public commenter stated 
that proposed Subunit 2B incorrectly describes the area proposed for 
designation as the former Snow Summit Ski Area, instead of the former 
Snow Forest Ski Area.
    Our Response: We appreciate the correction and have replaced ``Snow 
Summit Ski Area'' with ``Snow Forest Ski Area'' in this final rule (see 
``Unit Descriptions'' section below).

Public Comments

    (12) Comment: One commenter stated strong support for designation 
of critical habitat for these species but expressed concern that the 
proposed rule fails to indicate why vast areas of pebble plain habitat 
where the species are documented to occur were not included in the 
proposed designations. The commenter requested justification as to why 
certain occurrences or areas were not included as proposed critical 
habitat, including: (a) specific extant occurrences that contain the 
PCEs, (b) specific occupied areas where only a small portion of the 
occurrence was included, and (c) specific occupied areas where most but 
not the entire known occurrence was included.
    Our Response: The Act defines critical habitat as the specific 
areas within the geographical area occupied

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by the species at the time it is listed on which are found those 
physical and biological features (I) essential to the conservation of 
the species and (II) which may require special management 
considerations or protection; and specific areas outside the 
geographical area occupied by the species at the time it is listed upon 
a determination by the Secretary that such areas are essential for the 
conservation of the species. We believe that our proposed and final 
designations accurately describe all areas meeting the definition of 
critical habitat for Castilleja cinerea, Arenaria ursina and Eriogonum 
kennedyi var. austromontanum. As discussed in the proposed rule, we 
worked closely with SBNF personnel with knowledge of pebble plains 
plants and habitats to identify critical habitat for each of the three 
listed pebble plains plants based on several criteria (see ``Criteria 
Used to Identify Critical Habitat'' section of the proposed rule and 
this final rule). The areas delineated as critical habitat: (1) Support 
large or well-defined pebble plains or basins relative to other pebble 
plains in the complex; (2) support pebble plains least disturbed by 
anthropogenic threats (such as unauthorized vehicle use) relative to 
other pebble plains in the complex; (3) support areas containing unique 
habitat characteristics (e.g., soil type) or representing occurrences 
at the extremes of the species' geographic (e.g., northernmost extent) 
or elevational range (e.g., highest or lowest elevation); and (4) 
support morphologically unique species occurrences. Application of 
these criteria captures the physical and biological features that are 
essential to the conservation of the species, as identified in the 
species' primary constituent elements (PCEs), in the appropriate 
quantity and spatial arrangement essential for the conservation of all 
three species. Thus, not all areas supporting the identified PCEs will 
meet the definition of critical habitat.
    We recognize that our designations do not encompass all known 
occurrences of any of the three pebble plains plants as noted by the 
commenter. According to 2004 GIS data provided to the Service by the 
SBNF, the SBNF has mapped almost 300 individual pebble plains on and 
adjacent to the SBNF. Many of the 300 mapped pebble plains are small, 
isolated pebble plains that are degraded by surrounding residential 
development. We have determined that these small, isolated, degraded 
pebble plains are not essential to the conservation of the pebble 
plains plants and our criteria as described above did not capture these 
pebble plains. Although we are not designating all known occurrences of 
any of the three pebble plants, we believe that our criteria, and 
therefore the designations, are adequate to ensure the conservation of 
all three species throughout their extant ranges based on the best 
available information at this time. Species and plant communities that 
are protected across their ranges are expected to have lower 
likelihoods of extinction (Soule and Simberloff 1986; Scott et al 2001, 
pp. 1297-1300); our criteria identified multiple locations across the 
entire range of each species as essential habitat to prevent range 
collapse. Genetic variation in plants can result from the effects of 
population isolation and adaptation to locally distinct environments 
(Lesica and Allendorf 1995, pp. 754-757; Fraser 2000, pp. 49-51; 
Hamrick and Godt, pp. 291-295); our criteria identified populations 
that occur in unique habitats within the species' ranges, as well as 
habitats that support morphologically unique occurrences, in order to 
capture the range of environmental gradients in which these species are 
found. Conserving such areas aids in preserving the genetic variation 
that may result from adaptation to local environmental conditions, as 
documented in other plant species (e.g., see Hamrick and Godt pp. 299-
301; Millar and Libby 1991 pp. 150, 152-155). Furthermore, locations 
that possess unique ecological characteristics represent the full range 
of environmental variability where the pebble plains plants have 
evolved, and therefore are likely to promote the adaptation of these 
species to different environmental conditions.
    The commenter is incorrect in their characterization of our 
proposal and designations in stating that there are cases where we did 
not include an entire extent of an occupied pebble plain that we 
determined met the definition of critical habitat. In all cases we 
included the entire extent of any identified pebble plain in the 
proposed designations as delineated in the SBNF's 2004 GIS data 
provided to the Service by the SBNF.
    (13) Comment: One commenter indicated that the proposed 
designations for each of the three species are flawed because they do 
not include unoccupied habitat essential for recovery and that without 
such designated critical habitat these species' chances of persisting 
and recovering are greatly diminished.
    Our Response: In our proposed rule, we did not identify any 
additional areas outside the geographical area occupied by Arenaria 
ursina, Eriogonum kennedyi var. austromontanum, and Castilleja cinerea 
at the time they were listed as essential for the conservation of these 
species. The Act defines critical habitat as the specific areas within 
the geographical area occupied by the species at the time it is listed 
on which are found those physical and biological features (I) essential 
to the conservation of the species and (II) which may require special 
management considerations or protection; and specific areas outside the 
geographical area occupied by the species at the time it is listed upon 
a determination by the Secretary that such areas are essential for the 
conservation of the species. As discussed in response to comment 12, we 
believe that our proposed rule and these final designations of critical 
habitat meet the requirements of the Act and our proposed and final 
designations accurately describe all areas essential to the 
conservation of C. cinerea, A. ursina and E. kennedyi var. 
austromontanum. Therefore, consistent with 50 CFR 424.12(e), we are not 
designating any areas outside the geographical area presently occupied 
by these species as we believe that this designation is adequate to 
ensure the conservation of the species.
    These designations include all habitat areas currently determined 
to be necessary for these species' recovery. Critical habitat 
designations do not signal that habitat outside the proposed 
designation is unimportant or may not contribute to a species' 
recovery. Areas outside the final critical habitat designations will 
continue to be subject to conservation actions implemented under 
section 7(a)(1) of the Act, and regulatory protections afforded by the 
section 7(a)(2) jeopardy standard and the prohibitions of section 9 of 
the Act. Critical habitat designations based on the best available 
information at the time of designation will not control the direction 
and substance of future recovery plans, habitat conservation plans, or 
other species conservation planning efforts if information available at 
the time of these planning efforts calls for a different outcome. We 
recognize that the threats faced by these species may change in the 
future, however we base our critical habitat designations on the 
information available at the time of the designation and do not 
speculate as to what areas may be found essential if better information 
became available or what areas may become essential over time. The 
commenter did not include any specific data supporting their statement 
that unoccupied areas are essential for the recovery of any of the

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listed pebble plains plants and we are not aware of any studies or data 
that we did not consider. Should additional data become available 
concerning future threats to this species, we may revise this critical 
habitat designation if it is determined that the designation did not 
capture an area essential to the conservation of the species.
    (14) Comment: The San Bernardino National Forest (SBNF) disagreed 
with our rationale for designating critical habitat on their lands due 
to concerns over ongoing unauthorized activities. They state that while 
they share our concerns and will continue to work to improve compliance 
with existing management direction within their budget capabilities, 
unauthorized activities are an enforcement issue that will not be 
improved by the designations of critical habitat.
    Our Response: While we agree that the issue of unauthorized 
activities on USFS lands is an enforcement issue, we believe that the 
designations of critical habitat will benefit the three listed species 
in that it identifies those lands which are essential for the 
conservation of the species and can, if managed, provide for the 
conservation of each of the species.
    (15) Comment: The SBNF commented that they have been proactive in 
contributing to both survival and recovery of these three listed 
species and have developed and implemented a Pebble Plain Habitat 
Management Guide (USFS 2002), which includes these three species, and 
are working closely with the Service on the development of a recovery 
plan. They further stated that they recently revised their Land 
Management Plan (LMP) to incorporate management direction that they 
believe provides sufficient protection and management for the pebble 
plain species and their habitat. They further stated that designations 
of critical habitat on SBNF lands would not provide any additional 
benefit to the conservation of the three listed species or their 
habitat since all site-specific projects proposed by the SBNF are 
subject to section 7(a)(2) consultation with the Service and that 
designation would unnecessarily add to their analysis burden by 
requiring SBNF to make a determination of effect regarding critical 
habitat when consulting under section 7 of the Act.
    Our Response: As stated in the proposed rule, we acknowledge that 
the 2002 Management Guide (incorporated by reference into their revised 
LMP) was designed to provide management direction for the conservation 
of pebble plain habitat in the SBNF, to aid in recovery of the three 
federally-listed plants, and to improve conditions for Forest Sensitive 
species occurring in this habitat; the plan identifies the following 
management goals and actions necessary to reduce impacts to pebble 
plain habitat: protecting pebble plain habitat throughout its 
geographic range, reducing habitat loss and fragmentation, maintaining 
site viability, and encouraging compatible uses (USFS 2002, p. i). We 
appreciate and commend the efforts of the USFS to conserve federally 
listed species on their lands and recognize that the SBNF has completed 
many of the actions outlined in their 2002 Management Guide (USFS 2002) 
(incorporated by reference into their revised LMP) to avoid and 
minimize impacts to the three listed pebble plain species.
    We have determined that Forest Service lands meet the definitions 
of critical habitat and are essential to the conservation of the three 
listed pebble plain species (see ``Criteria Used to Identify Critical 
Habitat'' and ``Unit Descriptions'' sections below). We acknowledge 
that the LMP will benefit the three listed pebble plain species and 
their habitat. The LMP contains general provisions for species 
conservation and suggests specific management and conservation actions 
that will benefit these species and their PCEs. Implementation of the 
LMP should address known threats to these species on Forest Service 
lands. As stated above, we appreciate and commend the efforts of USFS 
to conserve federally listed species on their lands. However, Federal 
agencies have an independent responsibility under section 7(a)(1) of 
the Act to use their programs in furtherance of the Act and to utilize 
their authorities to carry out programs for the conservation of 
endangered and threatened species. USFS' development and implementation 
of the LMP, and specifically the Pebble Plain Habitat Management Guide, 
is consistent with the agency's statutory obligation under section 
7(a)(1) of the Act, and is not an appropriate basis for excluding 
essential habitat for the three listed pebble plain species on Forest 
Service lands from critical habitat designation.
    The Secretary may exclude an area from critical habitat under 
section 4(b)(2) of the Act after taking into consideration the economic 
impact, the impact on national security and any other relevant impact 
if he determines that the benefits of such exclusion outweigh the 
benefits of specifying such area, unless he determines that the 
exclusion would result in the extinction of the species concerned. We 
have considered the request from USFS that we exclude their lands based 
on the burden that the critical habitat designation would add to their 
section 7(a)(2) consultation requirement for actions on their lands and 
the fact that they completed consultation under section 7(a)(2) of the 
Act on their LMP. The primary benefit of including an area within a 
critical habitat designation is the protection provided by section 
7(a)(2) of the Act that directs Federal agencies to ensure that their 
actions do not result in the destruction or adverse modification of 
critical habitat. This benefit of designating an area as critical 
habitat is limited if the areas under consideration for designation 
occur on private lands for which there may not be a Federal nexus to 
invoke the protections of section 7(a)(2) of the Act. Federal lands by 
default have a Federal nexus and the intent of section 7 of the Act is 
to require Federal Agencies to consult on any action authorized, 
funded, or carried out by such agency to insure that the action will 
not jeopardize a listed species or destroy or adversely modify its 
critical habitat. Therefore, the benefits of inclusion of these areas 
are greater because they are Federal lands. We do not agree that any 
additional analysis required under section 7(a)(2) due to this critical 
habitat designation on Federal lands constitutes an undue burden for 
USFS such that the benefits of exclusion would outweigh the benefits of 
inclusion in this circumstance.
    Under the Joint Counterpart Endangered Species Act Section 7 
Consultation Regulations published in the Federal Register on December 
8, 2003 (68 FR 68254), projects that support the National Fire Plan 
that the Forest Service determines are ``not likely to adversely 
affect'' any listed species or designated critical habitat do not 
require any additional consultation under the Act with the Service. 
Projects within the scope of the National Fire Plan include projects 
such as, prescribed fire, mechanical fuels treatments (thinning and 
removal of fuels to prescribed objectives), emergency stabilization, 
burned area rehabilitation, road maintenance and operation activities, 
ecosystem restoration, and culvert replacement actions. Therefore, 
projects such as restoration, revegetation, and removal of nonnative 
species conducted in support of the National Fire Plan that are not 
likely to adversely affect federally-listed species should not add to 
USFS' workload or cost burden by requiring them to conduct a separate 
analysis and make a determination of effect on critical habitat when 
consulting under section 7 of the Act.

[[Page 73097]]

    Also, as part of our Section 7 consultation with the USFS on the 
LMP, the USFS has already consulted on various activities carried out 
on national forest lands including: roads and trail management; 
recreation management; special use permit administration; 
administrative infrastructure; fire and fuels management; livestock 
grazing and range management; minerals management; and law enforcement. 
In our 2005 biological opinion on the LMP, we determined that 
implementation of the plan was not likely to jeopardize the continued 
existence of the three listed pebble plain species. Since critical 
habitat has not been previously proposed or designated for any of these 
three species, it is anticipated that the consultation with the USFS 
regarding their current LMP will be reinitiated. However, because the 
USFS has already consulted with us on potential impacts to these 
species related to the activities outlined in the LMP, the USFS can 
supplement its analysis for those activities already analyzed in the 
LMP with the additional analysis required due to the designation of 
critical habitat. We do not believe that this additional analysis would 
place an undue burden on the USFS.
    In conclusion, we are designating Forest Service lands that meet 
the definition of critical habitat for the three pebble plains plant 
species because we have determined that the exclusion of Forest Service 
lands is not appropriate in light of the USFS' independent obligation 
under section 7(a)(1) of the Act to utilize the agency's authorities in 
furtherance of the purposes of the Act by carrying out programs for the 
conservation of the three pebble plains plants. Also, because of the 
agency's statutory obligations, the additional analysis under section 
7(a)(2) of the Act as a result of designation of critical habitat on 
National Forest lands should not be considered a relevant impact under 
Section 4(b)(2) or constitute an undue burden for USFS.

Comments Related to the Draft Economic Analysis (DEA)

    (16) Comment: One commenter stated that the Service should include 
all occupied habitat in the economic analysis and the final 
designations and that we should not rely on the flawed proposed 
designations as the bases for the economic analysis.
    Our Response: As discussed in the ``Criteria Used to Identify 
Critical Habitat'' section below, we worked closely with SBNF personnel 
with knowledge of pebble plains plants and habitats to identify 
critical habitat for each of the three listed pebble plains plants 
based on several criteria. We do not agree that the proposed 
designations are flawed, and it was appropriate to base the draft 
economic analysis on the areas included in the proposed rule.

Summary of Changes From the Proposed Rule

    The following changes to the proposed designations of critical 
habitat for these three species were made in this final designation:
     We revised the final designations to include information 
(e.g., occurrence data, threats, site-specific land use designations) 
received during the public comment periods (see ``Summary of Comments 
and Recommendations'' section above).
     We revised the final designations to further clarify the 
PCEs for each species (see ``Primary Constituent Elements'' section 
below).
     We renumbered the units/subunits defined in the proposed 
critical habitat designation to clarify the areas being designated for 
each species. To accomplish this, we assigned each species a unique 
identifier consisting of the first two letters of the genus and species 
names (i.e., ARUR, CACI, and ERKA). Each pebble plain that is being 
designated as critical habitat for an individual species was assigned a 
number that was then paired with the unique identifier for that 
species. The pebble plains being designated as critical habitat for an 
individual species are numbered consecutively (ARUR1, ARUR2, ARUR3, 
etc). Table 1 below outlines how the proposed critical habitat units/
subunits have been revised in this final rule. As part of this 
revision, we also provide maps identifying critical habitat and 
boundary descriptions for each species separately in this final rule 
(see ``Sec.  17.96 Critical habitat--plants'' section below). The 
renumbering of the critical habitat units for each species did not 
result in any changes to the unit boundaries as identified in the 
proposed designation.
     We revised the designation of proposed critical habitat 
Subunit 3A such that this pebble plain (ppn. 311) is now being 
designated as critical habitat for Castilleja cinerea (CACI 5) only 
(see ``Table 1'' and the ``Unit Descriptions'' sections below). A small 
sliver of this unit supports Arenaria ursina and Eriogonum kennedyi 
var. austromontanum. This sliver represents a small area of overlap 
between pebble plains 311 and 274. Although pebble plain 274 supports 
populations of A. ursina and E. kennedyi var. austromontanum, we 
previously determined that pebble plain 274 is not essential to the 
conservation of these two species. Because of this, and the fact that 
the vast majority of proposed Subunit 3A is occupied only by C. 
cinerea, no part of this unit (now referred to as CACI 5) is designated 
as critical habitat for Arenaria ursina or Eriogonum kennedyi var. 
austromontanum. This represents a reduction from the proposed rule in 
the overall area designated as critical habitat for each of these two 
species by 58 ac (23 ha).
     We re-evaluated lands in proposed critical habitat Subunit 
8A in the Sawmill pebble plain complex (ppn. 236) (now referred to as 
ARUA 13, CACI 17, and ERKA 11 in this final rule) based on recent 
aerial imagery and determined that we inadvertently included in the 
proposed designations an area that is currently developed for 
residential use. We subsequently removed an approximately 8 ac (3 ha) 
area of private land from proposed critical habitat Subunit 8A (ppn. 
236) from these final designations because this area does not contain 
the PCEs required by these species. Therefore, critical habitat for all 
three species was reduced by approximately 8 ac (3 ha) in this subunit. 
Other than the removal of these lands and the removal of proposed 
Subunit 3A for Arenaria ursina and Eriogonum kennedyi var. 
austromontanum mentioned above, no other significant changes were made 
to the areas proposed as critical habitat for these two species (see 
Table 1 below).
     In response to peer reviewer comments, we have clarified 
that identifying areas supporting morphologically unique species 
occurrences is a relevant factor in applying our criteria for 
determining critical habitat. A re-evaluation of habitat supporting 
pebble plains species based on information received from peer reviewers 
and in consideration of this factor identified two pebble plains not 
proposed as critical habitat (ppn. 286 and 293) (now referred to as 
CACI 23 and CACI 24 respectively) within the Sugarloaf Ridge complex 
west of Wildhorse Meadow Road. These two areas further represent pebble 
plains with a significant and distinctive population of C. cinerea, 
with shorter, maroon bracts, as opposed to C. cinerea in the rest of 
its range in Big Bear and Holcomb Valley, which have broader, yellow-
gold bracts. Furthermore, the pebble plain 293 represent a unique and 
higher elevational range than those in other complexes. These 
occurrences represent a unique portion of the range of environmental 
variability for this species and may be important for maintaining 
genetic diversity for the species. Therefore, we are including

[[Page 73098]]

CACI 23 (76 ac (31 ha)) and CACI 24 (190 ac (77 ha)) as critical 
habitat for C. cinerea only. This represents an increase from the 
proposed rule in the total amount of critical habitat designated from 
1,511 ac (611 ha) to 1,769 ac (722 ha) (see Table 1 below).
     We are finalizing the taxonomic revision of the family for 
Castilleja cinerea from the Scrophulariaceae to Orobanchaceae 
(broomrape) family discussed in the proposed critical habitat rule. 
This final rule includes a change to the list of Endangered and 
Threatened Plants at 50 CFR 17.12(h) to reflect this taxonomic change. 
This taxonomic change was explained by Olmstead (2002, pp. 13-22) and 
is formally accepted here.

  Table 1.--Changes in Unit/Subunit Numbers and Area (Acres (ac), Hectares (ha)) Between 2006 Proposed Critical Habitat and 2007 Final Critical Habitat
   for Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum. The Abbreviation ``PCH'' Refers to the 2006 Proposed Critical
                                    Habitat Rule (71 FR 67712) and ``FCH'' Refers to This Final Critical Habitat Rule
                                        [Area estimates reflect all land within critical habitat unit boundaries]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                       PCH Units or        FCH Units for A.      FCH Units for C.    FCH Units for E. k.
   USFS Pebble plain No. (ppn)*          subunits               ursina                cinerea        var. austromontanum    PCH ac (ha)     FCH ac (ha)
--------------------------------------------------------------------------------------------------------------------------------------------------------
100..............................  1A..................  ARUR 1..............  CACI 1..............  ERKA 1.............         69 (28)         69 (28)
87...............................  1B..................  ARUR 2..............  CACI 2..............  ERKA 2.............        229 (93)        229 (93)
248..............................  2A..................  ARUR 3..............  CACI 3..............  ...................          21 (9)          21 (9)
254..............................  2B..................  ARUR 4..............  CACI 4..............  ERKA 3.............           6 (2)           6 (2)
311..............................  3A..................  ....................  CACI 5..............  ...................         58 (23)         58 (23)
285, 309.........................  3B..................  ARUR 5..............  CACI 6..............  ...................       326 (132)       326 (132)
301..............................  4A..................  ARUR 6..............  CACI 7..............  ERKA 4.............          15 (6)          15 (6)
302..............................  4B..................  ARUR 7..............  CACI 8..............  ERKA 5.............         24 (10)         24 (10)
Juniper Point....................  4C..................  ....................  CACI 9..............  ...................           2 (1)           2 (1)
188..............................  5A..................  ARUR 8..............  CACI 10.............  ERKA 6.............         62 (25)         62 (25)
192..............................  5B..................  ARUR 9..............  CACI 11.............  ERKA 7.............         43 (17)         43 (17)
South Baldwin Meadow.............  5C..................  ....................  CACI 12.............  ...................       0.3 (0.1)       0.3 (0.1)
98, 109..........................  6A..................  ARUR 10.............  CACI 13.............  ERKA 8.............         28 (11)         28 (11)
153..............................  6B..................  ARUR 11.............  CACI 14.............  ERKA 9.............         44 (18)         44 (18)
128..............................  7A..................  ARUR 12.............  CACI 15.............  ERKA 10............       320 (129)       320 (129)
168..............................  7B..................  ....................  CACI 16.............  ...................           4 (2)           4 (2)
236..............................  8A..................  ARUR 13.............  CACI 17.............  ERKA 11............         44 (18)         36 (14)
224..............................  8B..................  ARUR 14.............  CACI 18.............  ERKA 12............           5 (2)           5 (2)
270..............................  9...................  ....................  CACI 19.............  ...................         26 (10)         26 (10)
212..............................  10..................  ARUR 15.............  CACI 20.............  ERKA 13............          23 (9)          23 (9)
294..............................  11A.................  ARUR 16.............  CACI 21.............  ...................        127 (51)        127 (51)
289..............................  11B.................  ARUR 17.............  CACI 22.............  ...................         34 (14)         34 (14)
286..............................  ....................  ....................  CACI 23.............  ...................           0 (0)         76 (31)
293..............................  ....................  ....................  CACI 24.............  ...................           0 (0)        190 (77)
                                  ----------------------------------------------------------------------------------------------------------------------
    Totals.......................  22..................  17..................  22..................  13.................     1,511 (611)    1,769 (722)
--------------------------------------------------------------------------------------------------------------------------------------------------------
* USFS Pebble Plain Management Guide (2002).

Critical Habitat

    Critical habitat is defined in section 3 of the Act as:
    (i) The specific areas within the geographical area occupied by a 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features
    (I) Essential to the conservation of the species and
    (II) Which may require special management considerations or 
protection; and
    (ii) Specific areas outside the geographical area occupied by a 
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 the use 
of all methods and procedures that are necessary to bring any 
endangered species or threatened species to the point at which the 
measures provided under 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 prohibition against Federal agencies carrying out, funding 
or authorizing the destruction or adverse modification of critical 
habitat. Section 7(a)(2) of the Act requires consultation on Federal 
actions that may affect 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 private landowners. Where a 
landowner 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 
landowner's obligation 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

[[Page 73099]]

geographical area occupied by the species at the time of listing must 
contain features that are essential to the conservation of the species, 
and be included only if those features may require special management 
considerations or protection. Critical habitat designations identify, 
to the extent known using the best scientific data available, habitat 
areas that provide essential life cycle needs of the species (i.e., 
areas on which are found the primary constituent elements, as defined 
at 50 CFR 424.12(b)).
    Under the Act, we can designate areas outside the geographical area 
occupied by the species at the time it is listed as critical habitat 
only when we determine that those areas are essential for the 
conservation of the species.
    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 are determining which areas should be proposed 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.
    Habitat is often dynamic, and species may move from one area to 
another over time. Furthermore, 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 promote the recovery of the species.
    Areas that are important to the conservation of the species, but 
are outside the critical habitat designations, will continue to be 
subject to conservation actions implemented by Federal agencies under 
section 7(a)(1) of the Act. Areas that support populations are also 
subject to the regulatory protections afforded by the section 7(a)(2) 
jeopardy standard, as determined on the basis of the best available 
scientific information at the time of the agency action. Federally 
funded or permitted projects affecting listed species outside their 
designated critical habitat areas may still result in jeopardy findings 
in some cases. 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 information available at the time of these planning 
efforts calls for a different outcome.

Primary Constituent Elements (PCEs)

    In accordance with section 3(5)(A)(i) of the Act and the 
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 identify the physical or biological features 
essential to the conservation of the species based on its biological 
needs. We consider the physical or biological features that are 
essential to the conservation of the species to be the primary 
constituent elements laid out in the appropriate quantity and spatial 
arrangement for the conservation of the species (PCEs). 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, and rearing (or development) 
of offspring; and
    (5) Habitats that are protected from disturbance or are 
representative of the historic, geographical, and ecological 
distributions of a species.
    We derive the specific primary constituent elements required for 
Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. 
austromontanum from the biological needs described in the Background 
section of the proposed rule (71 FR 67712; November 22, 2006). They 
include those habitat components essential for the biological needs of 
each species, including seed germination and seedling growth, flower 
production, pollination, fruit production and seed set, and genetic 
exchange.

Space for Individual and Population Growth and Normal Behavior; Food, 
Water, Air, Light, Minerals, or other Nutritional or Physiological 
Requirements

    Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. 
austromontanum require pebble plains habitat in dry meadow-like 
openings within upper montane coniferous forest, pinyon-juniper 
woodlands, or Great Basin sagebrush at elevations between 5,900 to 
9,800 feet (ft) (1,830 to 2,990 meters (m)) for individual and 
population growth (PCE 1).
    These typically treeless openings are the result of a combination 
of soil and climatic factors that support an assemblage of plant 
species found only in the San Bernardino Mountains, California (USFS 
2002, p. 12). Frost heaving and alternating wet and dry cycles force 
associated quartzite pebbles to the soil surface in areas of shallow 
clay deposits (PCE 2) to create the characteristic appearance of the 
pebble plains (Derby 1979, p. 61; Krantz 1983, p. 10; USFS 2002, p. 
22). These soils have an extremely slow infiltration rate and, thus, 
have a high runoff potential (Neel and Barrows 1990, p. 8).
    The establishment of tree species on pebble plains appears to be 
limited primarily by high clay content in the soil (Derby 1979, p. 74). 
However, the frost heave process that forces quartzite pebbles to the 
soil surface, creating the characteristic appearance of the pebble 
plains, also excludes large woody species from colonizing (Eliason 
2006). Trees that become established alter the surrounding microhabitat 
by increasing leaf litter and shading and probably reducing temperature 
extremes (USFS 2002, p. 15). The increase in leaf litter under trees 
appears to reduce the densities of all three of the listed pebble 
plains plants and increase tree and shrub seedlings under the tree 
canopy (Derby 1979, p. 72). Pebble plain species flourish in their 
specific environment, but they cannot compete with other plant species 
adapted to shaded areas, or areas where heavy litter layers accumulate 
(USFS 2002, p. 15).
    Pebble plains are typified by the presence of one or more of the 
following associated species: Ivesia argyrocoma, Eriogonum kennedyi 
var. kennedyi, Allium parryi, Antennaria dimorpha, Arabis parishii, 
Astragalus purshii var. lectulus, Dudleya abramsii var. affinis, 
Echinocereus engelmannii, Erigeron aphanactis var. congestus, Eriogonum

[[Page 73100]]

wrightii var. subscaposum, Lewisia rediviva var. minor, and Mimulus 
purpureus.
    In addition to pebble plain habitat, Castilleja cinerea is also 
found in dry meadow margin areas that lack either Arenaria ursina and 
or Eriogonum kennedyi var. austromontanum and quartzite pebbles or 
cobbles. However, as a semi-parasitic perennial plant, this root-
parasite requires host plant species found in pebble plain habitat (E. 
kennedyi var. austromontanum, E. kennedyi. var. kennedyi, and E. 
wrightii var. subscaposumon) and host plant species found in both 
pebble plain and non-pebble plain habitat (Artemisia tridentata, A. 
nova, and E. wrightii var. subscaposumon) for individual and population 
growth and for its nutritional and physiological requirements (PCE 3) 
(USFS 2002, p. 92).

Sites for Reproduction, Germination, Seed Dispersal, or Pollination

    While pollination (via selfing, wind, or insect) is important for 
maintaining genetic diversity within a pebble plain (Duffield 1972, pp. 
110-114; O'Brien 1979, pp. 67, 82, 97, 99; Freas and Murphy 1990, p. 
6), limited research indicates that little genetic material is 
exchanged among pebble plains (Freas and Murphy 1990, pp. 6-8). 
According to Freas and Murphy (1990, p. 6), observed pollen transfer 
distances were less than 13 ft (4 m).

Primary Constituent Elements for Arenaria ursina, Eriogonum kennedyi 
var. austromontanum and Castilleja cinerea

    Within the geographical area occupied by Arenaria ursina, 
Castilleja cinerea, and Eriogonum kennedyi var. austromontanum at the 
time of listing, we must identify the PCEs that may require special 
management considerations or protection. All areas designated as 
critical habitat for each taxon are currently occupied, within the 
taxon's historical geographic range, and contain sufficient PCEs to 
support at least one life history function.
    Based on our current knowledge of the life history, biology, and 
ecology of each of the species and the requirements of the habitat to 
sustain their essential life history functions, we have determined that 
the PCEs for Arenaria ursina and Eriogonum kennedyi var. austromontanum 
are:
    (1) Pebble plains in dry meadow-like openings within upper montane 
coniferous forest, pinyon-juniper woodlands, or Great Basin sagebrush 
in the San Bernardino Mountains of San Bernardino County, California; 
at elevations between 5,900 to 9,800 ft (1,830 to 2,990 m) that provide 
space for individual and population growth, reproduction and dispersal; 
and
    (2) Seasonally wet clay, or sandy clay soils, generally containing 
quartzite pebbles, subject to natural hydrological processes that 
include water hydrati