Federal Register: November 22, 2006 (Volume 71, Number 225)
DOCID: FR Doc 06-9194
DEPARTMENT OF THE INTERIOR
U.S. Citizenship and Immigration Services
CFR Citation: 50 CFR Part 17
RIN ID: RIN 1018-AU80
NOTICE: Part II
DOCUMENT ACTION: Proposed rule.
SUBJECT CATEGORY:
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)
DATES: We will accept comments from all interested parties until January 22, 2007. We must receive requests for public hearings, in writing, at the address shown in the ADDRESSES section by January 8, 2007.
DOCUMENT SUMMARY:
We, the U.S. Fish and Wildlife Service (Service), propose to designate critical habitat for Arenaria ursina (Bear Valley sandwort), Castilleja cinerea (ashgray Indian paintbrush), and Eriogonum kennedyi var. austromontanum (southern mountain wildbuckwheat) under the Endangered Species Act of 1973, as amended (Act). In total approximately 1,511 acres (ac) (611 hectares (ha)) of land in San Bernardino County, California, fall within the boundaries of the proposed critical habitat designation for these three plant species. The majority of the lands within the proposed designation are under Federal ownership (1,394 ac (564 ha)); however, some State (4 ac (2 ha)) and private lands (112 ac (45 ha)) are also included.
SUMMARY:
Interior Department, Fish and Wildlife Service,
SUPPLEMENTAL INFORMATION
Public Comments Solicited
We intend that any final action resulting from this proposal will
be as accurate and as effective as possible. Therefore, comments or
suggestions from the public, other concerned governmental agencies, the
scientific community, industry, or any other interested party
concerning this proposed rule are hereby solicited. Comments particularly are sought concerning:
(1) The reasons any habitat should or should not be determined to
be critical habitat as provided by section 4 of the Act, including
whether the benefit of designation will outweigh any threats to the species due to designation.
(2) Specific information on the amount and distribution of Arenaria
ursina, Castilleja cinerea, or Eriogonum kennedyi var. austromontanum
habitat, and what areas that were occupied at the time of listing that
contain features essential for the conservation of the species should
be included in the designation and why, and what areas that were not
occupied at the time of listing are essential to the conservation of the species and why.
(3) Land use designations and current or planned activities in the
subject areas and their possible impacts on proposed critical habitat.
(4) Any foreseeable economic, national security, or other potential
impacts resulting from the proposed designation and, in particular, any impacts on small entities.
(5) Whether our approach to designating critical habitat could be
improved or modified in any way to provide for greater public
participation and understanding, or to assist us in accommodating public concerns and comments.
If you wish to comment, you may submit your comments and materials concerning this proposal by any one of several methods (see ADDRESSES). Please submit email comments to fw8cfwocomments@fws.gov. Please include ``Attn: RIN 1018AU80'' in your email subject line and your name and return address in the body of your message. If you do not receive a confirmation from the system that we have received your message, contact us directly by calling our Carlsbad Fish and Wildlife Office at phone number 7604319440. Please note that comments must be received by the date specified in DATES in order to be considered.
Our practice is to make comments, including names and home
addresses of respondents, available for public review during regular
business hours. Individual respondents may request that we withhold
their names and home addresses, etc., but if you wish us to consider
withholding this information, you must state this prominently at the
beginning of your comments. In addition, you must present rationale for
withholding this information. This rationale must demonstrate that
disclosure would constitute a clearly unwarranted invasion of privacy.
Unsupported assertions will not meet this burden. In the absence of
exceptional, documentable circumstances, this information will be
released. We will always make submissions from organizations or
businesses, and from individuals identifying themselves as
representatives of or officials of organizations or businesses, available for public inspection in their entirety.
Role of Critical Habitat in Actual Practice of Administering and Implementing the Act
Attention to and protection of habitat is paramount to successful
conservation actions. The role that designation of critical habitat
plays in protecting habitat of listed species, however, is often
misunderstood. As discussed in more detail below in the discussion of
exclusions under section 4(b)(2) of the Act, there are significant
limitations on the regulatory effect of designation under section
7(a)(2) of the Act. In brief, (1) designation provides additional
protection to habitat only where there is a federal nexus; (2) the
protection is relevant only when, in the absence of designation,
destruction or adverse modification of the critical habitat would in
fact take place (in other words, other statutory or regulatory
protections, policies, or other factors relevant to agency decision
making would not prevent the destruction or adverse modification); and
(3) designation of critical habitat triggers the prohibition of
destruction or adverse modification of that habitat, but it does not require
[[Page 67713]]
specific actions to restore or improve habitat.
Currently, only 476 species, or 36 percent of the 1,311 listed species in the United States under the jurisdiction of the Service, have designated critical habitat. We address the habitat needs of all 1,311 listed species through conservation mechanisms such as listing, section 7 consultations, the section 4 recovery planning process, the section 9 protective prohibitions of unauthorized take, section 6 funding to the States, the section 10 incidental take permit process, and cooperative, nonregulatory efforts with private landowners. The Service believes that it is these measures that may make the difference between extinction and survival for many species.
In considering exclusions of areas proposed for designation, we evaluate the benefits of designation in light of Gifford Pinchot. In that case, the Ninth Circuit invalidated the Service's regulation defining ``destruction or adverse modification of critical habitat.'' In response, on December 9, 2004, the Director issued guidance to be considered in making section 7 adverse modification determinations. This proposed critical habitat designation does not use the invalidated regulation in our consideration of the benefits of including areas in this proposed designation. The Service will carefully manage future consultations that analyze impacts to designated critical habitat, particularly those that appear to be resulting in an adverse modification determination. Such consultations will be reviewed by the Regional Office prior to finalizing to ensure that an adequate analysis has been conducted that is informed by the Director's guidance.
On the other hand, to the extent that designation of critical habitat provides protection, that protection can come at significant social and economic cost. In addition, the mere administrative process of designation of critical habitat is expensive, timeconsuming, and controversial. The current statutory framework of critical habitat, combined with past judicial interpretations of the statute, make critical habitat the subject of excessive litigation. As a result, critical habitat designations are driven by litigation and courts rather than biology, and made at a time and under a timeframe that limits our ability to obtain and evaluate the scientific and other information required to make the designation most meaningful.
In light of these circumstances, the Service believes that
additional agency discretion would allow our focus to return to those
actions that provide the greatest benefit to the species most in need of protection.
Procedural and Resource Difficulties in Designating Critical Habitat
We have been inundated with lawsuits for our failure to designate critical habitat, and we face a growing number of lawsuits challenging critical habitat determinations once they are made. These lawsuits have subjected the Service to an everincreasing series of court orders and courtapproved settlement agreements, compliance with which now consumes nearly the entire listing program budget. This leaves the Service with little ability to prioritize its activities to direct scarce listing resources to the listing program actions with the most biologically urgent species conservation needs.
The consequence of the critical habitat litigation activity is that limited listing funds are used to defend active lawsuits, to respond to Notices of Intent to sue relative to critical habitat, and to comply with the growing number of adverse court orders. As a result, listing petition responses, the Service's own proposals to list critically imperiled species, and final listing determinations on existing proposals are all significantly delayed.
The accelerated schedules of courtordered designations have left the Service with limited ability to provide for public participation or to ensure a defectfree rulemaking process before making decisions on listing and critical habitat proposals, due to the risks associated with noncompliance with judicially imposed deadlines. This in turn fosters a second round of litigation in which those who fear adverse impacts from critical habitat designations challenge those designations. The cycle of litigation appears endless, and is very expensive, thus diverting resources from conservation actions that may provide relatively more benefit to imperiled species.
The costs resulting from the designation include legal costs, the cost of preparation and publication of the designation, the analysis of the economic effects and the cost of requesting and responding to public comment, and in some cases the costs of compliance with the National Environmental Policy Act (NEPA) (42 U.S.C. 4321 et seq.). These costs, which are not required for many other conservation actions, directly reduce the funds available for direct and tangible conservation actions.
Background
This proposed rule addresses critical habitat for Arenaria ursina (Bear Valley sandwort), Castilleja cinerea (ashgray Indian paintbrush), and Eriogonum kennedyi var. austromontanum (southern mountain wildbuckwheat) because they largely occupy the same habitat, referred to as pebble plain habitat. For additional information on the biology and ecology of these species, refer to the final rule listing them as threatened that was published in the Federal Register on September 14, 1998 (63 FR 49006). It is our intention to discuss only those topics directly relevant to the designation of critical habitat in this proposed rule.
Pebble Plain Habitat
Pebble plains are characteristically treeless openings surrounded by montane pinyonjuniper woodland or coniferous forest. This ``dry meadowlike'' habitat, which occurs on clay soils covered with quartzite pebbles, is unique to the San Bernardino Mountains of San Bernardino County, California. Pebble plains are remnants of a Pleistocene lake bed (Derby 1979, pp. 1114; Krantz 1983, pp. 910). Pebble plains are the result of a combination of soil and climatic factors that support a unique assemblage of plant species, some of which are restricted endemics while others represent disjunct occurrences of species more common elsewhere (USFS 2002, p. 12).
Pebble plain vegetation is comprised of various combinations of the 73 plant taxa recorded from pebble plains (USFS 2002, p. 12). While Arenaria ursina and Eriogonum kennedyi var. austromontanum were the two indicator species that characterized pebble plains when they were first described as a unique habitat type (as pavement plains) (Derby 1979, p. 77), Ivesia argyrocoma (silverhaired ivesia) is also considered a strong indicator of pebble plain habitat (USFS 2002, p. 14). Castilleja cinerea is nearly restricted to pebble plain habitat but does occur in nonpebble plain habitat, such as upper montane coniferous forest, meadows, and pinyonjuniper woodland. These nonpebble plain areas lack either one or both of the two former indicator species and quartzite pebbles or cobbles.
Each of the three listed pebble plains species has a natural mosaic
distribution among the various pebble plain complexes. The distribution
of each plant may change locally over time but generally extends
throughout a pebble plain complex. The fact that these three plant taxa
essentially occupy the same habitat is reflected here in the [[Page 67714]]
description and mapping of the critical habitat units and subunits. In
a study on the distribution of pebble plain plant species within three
pebble plains in the San Bernardino Mountains, Derby (1979, p. 7778)
concluded that, while perennial plant species present on pebble plains
tend toward evenly spaced overall distributions, some perennial
species, including Arenaria ursina and Castilleja cinerea, are
restricted to microhabitat niches within the habitat (such as on
northwest exposures). Each of the pebble plain complexes identified by
the Forest Service supports all three of the pebble plain species with
five exceptions: Coxey Meadow, Rattlesnake, Grinnell Ridge, Snow
Valley, and Sugarloaf Ridge (USFS 2002). Coxey Meadow and Rattlesnake
complexes do not support any of the three listed species and are not
proposed as critical habitat. Grinnell Ridge and Snow Valley complexes
support only C. cinerea. Grinnell Ridge is not considered in this
proposed designation because the area was last surveyed in 1994 and we
are unable to determine whether the mapped area represents the species
occurrence or the pebble plain boundary (Eliason 2006b, p. 1). Of the
five pebble plain complexes mentioned above, only two, Snow Valley and
Sugarloaf Ridge, are being proposed as critical habitat for C. cinerea and A. ursina , respectively.
Pebble plain complexes were first described and delineated by Neal and Barrows (1990, p. 11) who grouped pebble plains that were clearly clustered and isolated from other complexes and presumed to have comparable origins. According to the final listing rule, nine pebble plain complexes were described at that time (Neel and Barrows 1990, pp. 133): Arrastre/Union Flat, Big Bear Lake, Coxey Meadow, Gold Mountain, Holcomb Valley, North Baldwin Lake Onyx Ridge/Broom Flat, Sawmill, and South Baldwin Ridge/Erwin Lake. The final listing rule also discussed pebble plains in the Lost Creek area (within the area now referred to as the Grinnell Ridge Complex) and the Snow Valley Ski area (within the area now referred to as Snow Valley Complex). The Grinnell Ridge and Snow Valley areas were named as pebble plain complexes in 2002 (USFS 2002, p. 30, 53). Of the 11 complexes discussed in the listing rule, all except Coxey Meadow were known to be occupied at that time (Table 1).
Each of the three listed species was known to occur in the 1970s,
prior to the time of listing, on pebble plains within the area now
referred to as the Fawnskin Complex (CNDDB 1997a, 1997b, 1997c)
(
Species Descriptions
Arenaria ursina (Bear Valley sandwort)
Arenaria ursina is a low tufted perennial plant in the Caryophyllaceae (pink) family. A. ursina produces seeds by selfing (selfpollinating) and entomophilous (insectmediated) outcrossing (O'Brien 1979, p. 80). The seeds of Arenaria ursina are flat, reticulate, measure 2 millimeters (mm) (0.079 inches (in)) long, remain in open erect capsules for up to 2 months, and can bounce out of the capsule in a strong wind (O'Brien 1979, p. 81). Small syrphid flies and bees appear to be the primary insect pollinators for this species (O'Brien 1979, p. 82; Freas and Murphy 1990, p. 6). However, Freas and Murphy (1990, pp. 7, 8) state that there is no evidence indicating that either wind or pollinatormediated dispersal plays a role in gene flow between pebble plain sites. Therefore, it appears that species persistence in each pebble plain is regulated by internal processes.
Arenaria ursina is found on pebble plains and dry slopes in pinyon
and juniper woodland in the northeastern San Bernardino Mountains (63
FR 49006; September 14, 1998). A. ursina has one of the most restricted
ranges of any of the pebble plain restricted endemic plants, second
only to Eriogonum kennedyi var. austromontanum. A. ursina exhibits a
patchy distribution within pebble plains and appears to prefer areas
with low levels of shade and leaf litter accumulation (Derby 1979, p. 42). Species associated with A. ursina include E. k. var.
austromontanum, Antennaria dimorpha, Arabis parishii, Dudleya abramsii spp. affinis, and Ivesia argyrocoma (USFS 2002, p. 17).
According to the final listing rule, Arenaria ursina was known from
eight pebble plain complexes in the vicinity of Big Bear and Baldwin
Lakes (63 FR 49006). This species was also known to occur in the 1970s,
prior to the time of listing, on pebble plains within the area now
referred to as the Fawnskin Complex (CNDDB 1997a). As stated above,
while this area was not identified in the final listing rule, we
consider it to be occupied at the time of listing based on prelisting
occupancy records. Currently, A. ursina is known to occupy 10 pebble
plain complexes in the vicinity of Big Bear and Baldwin Lakes (USFS
2002, p. 90). This occupancy includes the Sugarloaf Ridge complex,
which was found to be occupied by this species about 3 years ago, after
the 2002 Pebble Plain Management Guide was finalized (Eliason 2006a, p. 1).
Table 1.Pebble Plain Complexes in the San Bernardino Mountains, California, Occupied at the Time of Listing
(OTL), Currently Occupied (CO), or not Known To Be Occupied at the Time of Listing or Currently (NO) for Each of
the Three Listed Pebble Plain Species
[Pebble plain complex names follow USFS 2002]
Castilleja Eriogonum kennedy
Pebble plain complex Arenaria ursina cinerea var. austromontanum
1............................. Arrastre/Union Flat.. OTL, CO......... OTL, CO......... OTL, CO
2............................. Big Bear Lake........ OTL, CO......... OTL, CO......... OTL, CO
3............................. Coxey Meadow......... NO.............. NO.............. NO
4............................. Gold Mountain........ OTL, CO......... OTL, CO......... OTL, CO
5............................. Holcomb Valley....... OTL, CO......... OTL, CO......... OTL, CO
6............................. North Baldwin Lake... OTL, CO......... OTL, CO......... OTL, CO
7............................. Broom Flat (Onyx OTL, CO......... OTL, CO......... CO Ridge).
8............................. Sawmill.............. OTL, CO......... OTL, CO......... OTL, CO
9............................. South Baldwin Ridge/ OTL, CO......... OTL, CO......... OTL, CO Erwin Lake.
10............................ Grinnell Ridge....... ................ OTL............. [[Page 67715]]
11............................ Snow Valley.......... ................ OTL, CO.........
12............................ Fawnskin............. OTL, CO......... OTL, CO......... OTL, CO
13............................ Rattlesnake.......... NO.............. NO.............. NO
14............................ Sugarloaf Ridge...... CO.............. CO.............. Castilleja cinerea (ashgray paintbrush)
Castilleja cinerea is a semiparasitic perennial in the Scrophulariaceae (figwort) family. Recent taxonomic studies (Olmstead et al. 2001, p. 350) have placed the genus Castilleja and other plant genera formerly in the Scrophulariaceae into the Orobanchaceae (broomrape) family. This proposed 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. 1322) and is accepted here.
Known hosts for this rootparasite in pebble plain habitat include Eriogonum kennedyi var. austromontanum, E. k. var. kennedyi, E. wrightii var. subscaposum, and in nonpebble plain meadow margin habitat include Artemisia tridentata, A. nova, and A. ludoviciana (USFS 2002, p. 92). All Castilleja species are parasitic, and this species is distinguished from other Castilleja in its range by shorthaired stems and leaves, yellowish flowers, calyx lobes of equal length, and perennial nature (63 FR 49006; September 14, 1998).
The seeds of Castilleja cinerea are loosely held in the open erect capsules, taking about a month to fall onto the ground after maturation. The dispersal agent (such as wind or foraging animals) for this species is unknown. Moreover, seeds are the product of self pollinating outcrossing (O'Brien 1979, p. 67), and insect visitation does not appear significant for Castilleja species (Duffield 1972, pp. 110114; O'Brien 1979, p. 69; Freas and Murphy 1990, p. 6).
Castilleja cinerea is usually found on pebble plain habitat, but also occurs in other habitats including upper montane coniferous forest, meadows, and pinyonjuniper woodland (USFS 2002, pp. 17, 92). Species associated with C. cinerea on pebble plain habitat include Artemisia nova, Eriogonum kennedyi var. austromontanum, Erigeron aphanactis (fleabane daisy), and Poa secunda ssp. secunda (pine bluegrass) (USFS 2002, p. 17).
According to the final listing rule (63 FR 49006; September 14, 1998), Castilleja cinerea was known from fewer than 20 localities, mostly on pebble plains, but also from several localities in pine forest habitats near the Snow Valley Ski area, along Sugarloaf Ridge (part of the Sawmill Complex), and in the vicinity of Lost Creek (within the area now referred to as the Grinnell Ridge Complex). This species was also known in the 1970s, prior to the time of listing, to occur on pebble plains within the area now referred to as the Fawnskin Complex and in nonpebble plain meadow margin habitat adjacent to Big Bear and Baldwin lakes (CNDDB 1997b). While these areas were not identified in the final listing rule, we consider them to be occupied at the time of listing based on prelisting occupancy records in our files (CNDDB 1997b). This species is now known to occur in 11 pebble plain complexes (see Table 1 above) and several nonpebble plain habitat areas (USFS 2002, p. 92). The 11 pebble plain complexes include the Sugarloaf Ridge Complex, which was found to be occupied by this species about 3 years ago, after the 2002 Pebble Plain Management Guide was finalized (Eliason 2006a, p. 1). While the pebble plain in the Grinnell Ridge Complex was known to be occupied by Castilleja cinerea at the time of listing (Table 1), the area was last surveyed in 1994 and we are unable to determine whether the mapped area represents the species occurrence or the pebble plain boundary (Eliason 2006b, p. 1). Additional information is needed for us to determine if this area should be considered currently occupied by this species.
Eriogonum kennedyi var. austromontanum (southern mountain wild buckwheat)
Eriogonum kennedyi var. austromontanum is a woodybased, cushion like, perennial plant in the Polygonaceae (buckwheat family). This species is often confused with E. k. var. kennedyi, E. k. var. alpigenum, or E. wrightii spp. subscaposum, but it can be distinguished from these taxa by its longer, unbranched flower stalks, leaves, fruits, and involucres (63 FR 49006; USFS 2002, pp. 9394).
Eriogonum kennedyi var. austromontanum produces seeds by self pollinating and insectmediated outcrossing (O'Brien 1979, p. 97). Numerous types of wasps, bees, and flies have been recorded as pollinators on this plant (O'Brien 1979, p. 99; Freas and Murphy 1990, p. 6). This species produces singleseeded fruits, the majority of which remain at the base of the parent plant after falling off (O'Brien 1979, p. 99). While Freas and Murphy (1990, pp. 7, 8) detected seeds of either E. k. var austromontanum or E. k. var. kennedyi in seed traps placed along pebble plainforest edges, they state that there is no evidence indicating that either wind or pollinatormediated dispersal plays a role in gene flow between pebble plain sites. Therefore, it appears that species persistence in each pebble plain is regulated by internal processes.
Eriogonum kennedyi var. austromontanum has the most restricted range of any of the pebble plain restricted endemic plants, although it may be the dominant plant on pebble plains where it occurs. It was one of the taxa identified as characteristic of the unique pebble plain habitat first described by Derby (1979, p. 32). Although this taxon typically occupies clay soils with pebbles or cobbles, E. k. var. austromontanum also occurs on sandy, clay soils (e.g., Burnt Flat) or clay soils lacking pebbles or cobbles (e.g., areas at North Baldwin Lake) (USFS 2002, p. 94). This species prefers areas with low levels of shade and leaf litter accumulation (Derby 1979, p. 42).
Eriogonum kennedyi var. austromontanum was known from seven pebble
plain complexes at the time of listing (63 FR 49006; September 14,
1998) (see Table 1 above). This species was also known in the 1970s, prior to the time of listing, to occur on
[[Page 67716]]
pebble plains within the area now referred to as the Fawnskin Complex
(CNDDB 1997c). As stated above, while this area was not identified in
the final listing rule, we consider it to be occupied at the time of
listing based on prelisting occupancy records in our files (CNDDB
1997c). The species is now known to occur in nine pebble plain
complexes (see Table 1 above) including the Broom Flat Complex that was
not known to be occupied by this species at the time of listing (USFS
2002, pp. 62, 94). However, the Broom Flat complex was known to be
occupied by Arenaria ursina and Castilleja cinerea at the time of listing.
Threats to Pebble Plain Habitat
Major threats to the listed pebble plains species include development on private lands, offhighway vehicle (OHV) use off of designated routes, road maintenance activities, ground disturbance that affects surface hydrology, mining activities, recreational activities, habitat fragmentation, and the invasion of nonnative Bromus tectorum (cheatgrass). See the ``Special Management Considerations or Protection'' section for further discussion of the threats to the listed pebble plains species.
Previous Federal Actions
Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum were federally listed as threatened on September 14, 1998 (63 FR 49006). These species are not currently listed as endangered, threatened, or rare by the State of California. At the time these plants were federally listed, the Service compared the value of designating critical habitat to the detrimental effects of increased collection, vandalism, and other human activities. The Service found, based on these factors, that designation of critical habitat for A. ursina, C. cinerea, and E. k. var. austromontanum was not prudent. On September 13, 2004, the Center for Biological Diversity and the California Native Plant Society filed a joint lawsuit challenging the Service's failure to designate critical habitat for six California plant species, including A. ursina, C. cinerea, and E. k. var. austromontanum (Center for Biological Diversity, et al. v. Norton, No. ED CV041150 RT (SGLx)). In an April 14, 2005, settlement agreement, the Service agreed 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. This proposed rule complies with the April 14, 2005, settlement agreement.
We have reconsidered our not prudent finding, and now believe that identification of primary constituent elements and essential areas (critical habitat designation) may provide educational information to individuals, local and State governments, and other entities. Because these species are so limited in their ecological and geographical ranges, and many of these pebble plains are adjacent to or bisected by classified and unclassified roads, most landowners and collectors have been aware of their presence since publication of the final listing rule in 1998. We do not have any documentation that overcollection has increased significantly since these species were listed and now believe that the benefits of identifying essential habitat for these species outweighs the potential risk of overcollection.
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) that 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 to use and the use of all methods and procedures which are necessary to bring any endangered species 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 prohibition against destruction or adverse modification of critical habitat with regard to actions carried out, funded, or authorized by a Federal agency. Section 7 requires consultation on Federal actions that are 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 government or public access to private lands. Section 7 is a purely protective measure and does not require implementation of restoration, recovery, or enhancement measures.
To be included in a critical habitat designation, the habitat within the area occupied by the species must first have features that are essential to the conservation of the species. 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)). Habitat occupied at the time of listing may be included in critical habitat only if the essential features thereon may require special management considerations or protection. Areas outside of the geographic area occupied by the species at the time of listing may only be included in critical habitat if they are essential for the conservation of the species. Accordingly, when the best available scientific data do not demonstrate that the conservation needs of the species require additional areas, we will not designate critical habitat in areas outside the geographical area occupied by the species at the time of listing. An area currently occupied by the species but not known to be occupied at the time of listing will likely, but not always, be essential to the conservation of the species and, therefore, typically included in the critical habitat designation.
The Service's Policy on Information Standards Under the Endangered
Species Act, published in the Federal Register on July 1, 1994 (59 FR
34271), and Section 515 of the Treasury and General Government
Appropriations Act for Fiscal Year 2001 (Pub. L. 106554; H.R. 5658)
and the associated Information Quality Guidelines issued by the
Service, provide criteria, establish procedures, and provide guidance
to ensure that decisions made by the Service represent the best
scientific data available. They require Service 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
determining which areas are critical habitat, a primary source of
information is generally the listing package for the species. Additional
[[Page 67717]]
information sources include the recovery plan for the species, articles
in peerreviewed 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. All information is used in accordance with the
provisions of Section 515 of the Treasury and General Government
Appropriations Act for Fiscal Year 2001 (Pub. L. 106554; H.R. 5658)
and the associated Information Quality Guidelines issued by the Service.
Section 4 of the Act requires that we designate critical habitat on the basis of the best scientific data available. Habitat is often dynamic, and species may move from one area to another over time. Furthermore, we recognize that designation of critical habitat may not include all of the habitat areas that may eventually be determined to be necessary for the recovery of the species. For these reasons, critical habitat designations do not signal that habitat outside the designation is unimportant or may not be required for recovery.
Areas that support populations, but are outside the critical habitat designation, will continue to be subject to conservation actions implemented under section 7(a)(1) of the Act and to the regulatory protections afforded by the section 7(a)(2) jeopardy standard, as determined on the basis of the best available information at the time of the 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, or other species conservation planning efforts if new information available to these planning efforts calls for a different outcome. Methods
As required by section 4(b)(2) of the Act, we use the best scientific data available in determining areas that contain the features that are essential to the conservation of Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum and the habitat requirements of these species. These sources included, but were not limited to, the proposed (60 FR 39337; August 2, 1995) and final (63 FR 49006; September 14, 1998) rules to list these species; data and information published in peerreviewed articles; data and information contained in reports prepared for or by the U.S. Forest Service (USFS); discussions and site visits with species experts including USFS personnel; data and information presented in academic research theses and dissertations; data provided by the California Department of Fish and Game Natural Diversity Data Base (CNDDB); herbarium records; data submitted during section 7 consultations; and regional Geographic Information Systems (GIS) data.
Primary Constituent Elements
In accordance with section 3(5)(A)(i) of the Act and regulations at 50 CFR 424.12, in determining which areas to propose as critical habitat, we consider those areas occupied by the species at the time of listing that contain physical and biological features (primary constituent elements or PCEs) that are essential to the conservation of the species, and that may require special management considerations or protection. These include, but are not limited to, space for individual and population growth and for normal behavior; food, water, air, light, minerals, or other nutritional or physiological requirements; cover or shelter; sites for breeding, reproduction, and rearing of offspring germination and seed dispersal; and habitats that are protected from disturbance or are representative of the historic geographical and ecological distributions of a species.
The specific primary constituent elements required for Arenaria
ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum
are derived from the biological needs described in the Background
section of this proposal. 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 or dry meadows in openings within upper montane coniferous forest, pinyon'juniper woodlands, or Mojavean desert scrub at elevations between 5,900 to 9,800 feet (1,830 to 2,990 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). 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 species 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 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
Eriogonum kennedyi var. austromontanum or both and quartzite pebbles or
cobbles. However, as a semiparasitic perennial plant, this root
parasite requires host plant species found in pebble plain habitat
(Eriogonum kennedyi var. austromontanum, E. k. var. kennedyi, and E.
wrightii var. subscaposumon) and host plant species found in both
pebble plain and nonpebble 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).
[[Page 67718]]
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.
110114; 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. 68).
According to Freas and Murphy (1990, p. 6), observed pollen transfer distances were less than 4 meters (13 feet).
Primary Constituent Elements for Arenaria ursina, Eriogonum kennedyi var. austromontanum and Castilleja cinerea
Under our regulations, we are required to identify the known physical and biological features (PCEs) essential to the conservation of Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum. All areas proposed 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 the species and the requirements of the habitat to sustain
the essential life history functions of the species, we have determined
that the PCEs for Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum are:
(1) Pebble plains or dry meadows in openings within upper montane
coniferous forest, pinyon'juniper woodlands, or Mojavean desert scrub
in the San Bernardino Mountains of San Bernardino County, California;
at elevations between 5,900 to 9,800 feet (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 hydrating the soil and freezing in winter and drying in
summer causing lifting and churning of included pebbles, to provide
adequate water, air, minerals, and other nutritional or physiological requirements to the species.
We have determined that Castilleja cinerea also requires the following PCE:
(3) The presence of one or more of its known host species, such as
Eriogonum kennedyi var. austromontanum, E. k. var. kennedyi, and E.
wrightii var. subscaposumon in pebble plain habitat and species such as
Artemisia tridentata, A. nova, and E. wrightii var. subscaposumon in
pebble plain and nonpebble plain meadow margin habitat that provide some of the physiological requirements for this species.
This proposed designation is designed for the conservation of those areas containing the PCEs necessary to support the life history functions that are the basis for the proposal. Because not all life history functions require all the PCEs, not all critical habitat will contain all the PCEs.
Units are designated based on sufficient PCEs being present to support one or more of the species' life history functions. Some units contain all PCEs and support multiple life processes, while some units contain only a portion of the PCEs necessary to support the species' particular use of that habitat.
Criteria Used To Identify Critical Habitat
As required by section 4(b)(1)(A) of the Act, we use the best scientific and commercial data available in determining areas that contain the features that are essential to the conservation of Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum. To delineate the proposed critical habitat boundaries associated with habitat occupied by the listed species, we relied on GIS data provided by the USFS's San Bernardino National Forest (SBNF). SBNF personnel mapped pebble plain and some nonpebble plain habitat on SBNF lands for the 2002 Pebble Plain Management Guide using a combination of 1:10,000 air photos, 1:24,000 orthographic photos, 1:24,000 topographic maps, and groundtruthing with global positioning system (GPS) units (USFS 2002, p. 30). We also worked with SBNF personnel with species and habitat expertise to determine the status of pebble plains being considered for designation (habitat quality and land ownership).
Working with SBNF personnel with knowledge of pebble plains species and habitats, we then identified pebble plains within each of the 12 occupied pebble plain complexes that met the following criteria for each of the three listed species: (1) Contained the PCEs, (2) known to be occupied at the time of listing and currently occupied; (3) if not known to be occupied at the time of listing, currently occupied and essential to the conservation of the species; (4) large or welldefined relative to other pebble plains in the complex; and (5) least disturbed by anthropogenic threats (such as unauthorized vehicle use) relative to other pebble plains in the complex. The majority of the pebble plains (14 of 22) being proposed as critical habitat contain all three of the listed species. To the extent possible, we included the larger pebble plains within a complex that were proximal to other relatively large pebble plains occupied by the listed species in order to capture areas with presumably higher species diversity. Ciano (1984, p. 14) examined species variability on pebble plains in relation to island biogeography theory and found that the number of species within a pebble plain increased with the size of the pebble plain and decreased as distance from other pebble plains increased; thus larger pebble plains located closer to other pebble plains had higher species diversity.
For nonpebble plain meadow margin areas (Mojavean desert scrub PCE 1) containing Castilleja cinerea, we identified those occupied areas that: (1) Contain unique habitat characteristics (such as soil typePCE 2)) relative to other nonpebble plain areas occupied by the species, and (2) are within areas with the least amount of disturbance by anthropogenic threats (such as unauthorized vehicle use) relative to other occupied nonpebble plain habitat.
For the purposes of this rule, occupied ``at the time of listing'' is defined as those occurrences or areas identified in the final listing rule (63 FR 49006; September 14, 1998) or those areas known to be occupied prior to the publication of the listing rule according to occupancy data in our files (CNDDB 1997a, 1997b, 1997c). Table 1 above lists the pebble plain complexes occupied at the time of listing and currently occupied for each of the three listed pebble plain species. We are not proposing any unoccupied areas or areas outside the geographic area presently occupied by the species.
When determining proposed critical habitat boundaries, 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 Arenaria ursina, Castilleja cinerea, and Eriogonum
kennedyi var. austromontanum. The scale of the maps prepared under the
parameters for publication within the Code of Federal Regulations may
not reflect the exclusion of such developed areas. Any such structures
and the land under them inadvertently left inside critical habitat
boundaries shown on the maps of this proposed rule have been excluded
by text in the proposed rule and are not proposed for designation as
critical habitat. Therefore, Federal actions limited to these areas would not trigger
[[Page 67719]]
section 7 consultation, unless they may affect the species or primary constituent elements in adjacent critical habitat.
We are proposing to designate critical habitat on lands that we have determined were occupied at the time of listing or are currently occupied by Arenaria ursina, Castilleja cinerea, or Eriogonum kennedyi var. austromontanum and that contain one or more of the primary constituent elements to support life history functions essential for the conservation of these species.
Special Management Considerations or Protection
When designating critical habitat, we assess whether the areas determined to be occupied at the time of listing contain primary constituent elements that may require special management considerations or protection.
As stated in the final listing rule, major threats to all three listed pebble plains species throughout their range include land development, offhighway vehicle (OHV) use off of designated routes, road maintenance activities, ground disturbance that affects surface hydrology, mining activities, recreational activities, and nonnative plant species (63 FR 49006; September 14, 1998). The use of OHVs off of designated routes has historically been the greatest threat to pebble plains habitat (63 FR 49006). The primary constituent elements for the listed pebble plains species may require special management considerations or protection to minimize impacts associated with(1) Vehicle use and road maintenance; (2) recreational activities; and (3) the presence of nonnative species (63 FR 49006; USFS 2002, p. 17; USFS 2005, pp. 207, 249, 293).
All of the pebble plain complexes have some degree of impact associated with the USFSauthorized and unauthorized use of vehicles and associated maintenance (USFS 2002, pp. 20, 25, 3068). Vehicle use and road maintenance could introduce invasive, nonnative plants, increase the potential for unauthorized routes to develop (leading to the crushing and burying of individual plants and soil compaction), and cover individuals with dust and mud that can impair physiological functions (USFS 2002, p. 20; USFWS 2005, pp. 233, 238, 243).
Along with soil compaction, soil erosion resulting from vehicle use could significantly alter the soil composition required by the listed species (PCE 2). During the wet season, vehicle traffic directly disturbs or destroys vegetation and creates deep ruts that change the hydrological patterns over the pebble plain (USFS 2002, p. 20). Vehicle traffic also increases breakdown in natural soil aggregates (structure) (Sadler, pers. comm. 1989 cited in USFS 2002, p. 22). Changes in the hydrological pattern associated with a pebble plain could alter the soil composition by allowing for erosion of clay sediments during rainfall events, leaving only large cobbles and pebbles (PCE 2). These changes to the soil morphology and composition could result in alterations to the vegetation structure and composition of the area, allowing for the invasion of native and nonnative plant species that could outcomplete the listed species for space and resources and further alter the soil composition by increasing organic debris (PCEs 1, 2, and 3).
The invasion of nonnative plant species can result in crowding, overshadowing, and altering fuel loads and hydrology (USFS 2002, p. 25). While fire has not been considered an important factor in shaping the pebble plain community, the establishment of an introduced species, such as cheatgrass, might provide the fine fuels to allow fire to spread more readily and result in alterations to the composition and structure of the pebble plain community (USFS 2002, pp. 1920). Pebble plain species flourish in their specific environment, but they cannot complete with other plant species adapted to shaded areas or sites where heavy litter layers accumulate (USFS 2002, p. 15). The invasion of nonnative species may alter the soil composition (PCE 2) or cause an increase in the amount of leaf litter, allowing for the eventual encroachment of adjacent native shrub and tree species into the pebble plain, and diminishing the habitat available to pebble plain obligate species and host species (PCE 1). Derby (1979, p. 72) found lower densities of all three of the listed species in pebble plain areas where leaf litter was abundant under trees.
The USFS prepared the 2002 Pebble Plain Management Guide (USFS 2002, p. i) as an update to the 1990 Pebble Plain Habitat Management Guide and Action Plan by Neal and Barrows. The 2002 Pebble Plain Management Guide 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 2002 Pebble Plain Management Guide identifies the following management goals necessary to reduce impacts to pebble plain habitatprotecting pebble plain habitat throughout its geographic range, reducing habitat loss and fragmentation, maintaining site viability, and encouraging compatible uses (USFS 2002, p. i).
The USFS has completed many of the actions outlined in the plan to avoid and minimize impacts to the three listed pebble plain species including, but not limited to permanently closing some roads bisecting pebble plains, installing fencing or gates along some roads to prevent unauthorized access onto adjacent pebble plains, establishing alternate trails, adding law enforcement patrols, relocating special events out of pebble plain habitat, and posting of signs to keep vehicles out of sensitive habitat; however, ongoing unauthorized use is still occurring in all of the pebble plain complexes (USFS 2002, pp. 3068). See the ``Unit Description'' section for a discussion of the special management considerations or protection that may be needed for each unit or subunit being proposed as critical habitat.
Proposed Critical Habitat Designation
We are proposing a total of 1,511 ac (611 ha) of Federal, State, and private land within 11 units, with 9 of these units further divided into 20 subunits, as critical habitat for Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum. Table 2 below provides the approximate area of each unit or subunit being proposed as critical habitat for Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum. Table 3 below provides landownership sizes in each unit or subunit. Table 4 outlines the units and subunits proposed as critical habitat and the total area for each species. Since these species often occur in the same pebble plains, the total area being proposed as critical habitat for each species will not equal the total area being proposed for all three species combined.
While the pebble plain in the Grinnell Ridge Complex was known to
be occupied by Castilleja cinerea at the time of listing (Table 1), the
area was last surveyed in 1994 (Eliason 2006b, p. 1), and we cannot
determine whether the mapped area represents the species occurrence or
the pebble plain boundary. Moreover, this pebble plain is located in a
remote area in the San Gorgonio Wilderness Area on SBNF and is not
easily accessible. We do not have sufficient information to determine
that this area has the features that are essential to the conservation
of the species as defined for the purposes of this critical habitat designation, and therefore we are not proposing to
[[Page 67720]]
designate the Grinnell Ridge Complex as essential habitat.
The critical habitat areas described below constitute our best
assessment at this time of areas determined to be occupied at the time
of listing, containing primary constituent elements that may require
special management considerations or protection, and those additional
areas that were not occupied at the time of listing but were found to
be essential to the conservation of Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum.
Table 2.Proposed Critical Habitat (acres (ac), hectares (ha)) for Arenaria ursina, Castilleja cinerea, and
Eriogonum kennedyi var. austromontanum. The Abbreviation ``ppn.'' Refers to the Pebble Plain Number Identified
in the USFS Pebble Plain Management Guide (2002)
[Area estimates reflect all land within critical habitat unit boundaries]
Total area Total area Listed species in
Proposed critical habitat unit Pebble plain complex and of unit (ac of subunit unit or subunit
subunit name (ha)) (ac (ha)) \1\
1..................................... Arrastre/Union Flat
1A (ppn. 100)............ 298 (121) 69 (28) 1,2,3
1B (ppn. 87)............. ............ 229 (93) 1,2,3
2..................................... Big Bear Lake
2A (ppn. 248)............ 28 (11) 21 (9) 1,2
2B (ppn. 254)............ ............ 6 (2) 1,2,3
3..................................... Broom Flat
3A (ppn. 311)............ 384 (156) 58 (23) 1,2,3
3B (ppn. 285 & 309)...... ............ 326 (132) 1,2
4..................................... Fawnskin
4A (ppn. 301)............ 41 (17) 15 (6) 1,2,3
4B (ppn. 302)............ ............ 24 (10) 1,2,3
4C (Juniper Point)....... ............ 2 (1) 2
5..................................... Gold Mountain
5A (ppn. 188)............ 105 (42) 62 (25) 1,2,3
5B (ppn. 192)............ ............ 43 (17) 1,2,3
5C (South Baldwin meadow) ............ 0.3 (0.1) 2
6..................................... Holcomb Valley
6A (ppn. 98 & 109)....... 72 (29) 28 (11) 1,2,3
6B (ppn. 153)............ ............ 44 (18) 1,2,3
7..................................... North Baldwin Lake
7A (ppn. 128)............ 351 (142) 320 (129) 1,2,3
7B (ppn. 168)............ ............ 4 (2) 2
8..................................... Sawmill
8A (ppn. 236)............ 50 (20) 44 (18) 1,2,3
8B (ppn. 224)............ ............ 5 (2) 1,2,3
9..................................... Snow Valley (ppn. 270)... 26 (10) NA 2
10.................................... South Baldwin Ridge/Erwin 23 (9) NA 1,2,3 Lake (ppn. 212).
11.................................... Sugarloaf Ridge
11A (ppn. 294)........... 161 (65) 127 (51) 1,2
11B (ppn. 289)........... ............ 34 (14) 1,2
Total............................. 22....................... 1,511 (611)
\1\ 1 = Arenaria ursina, 2 = Castilleja cinerea, 3 = Eriogonum kennedyi var. austromontanum.
Table 3.Landownership (acres (ac), hectares (ha)) in Units or Subunits
Being Proposed as Critical Habitat for Arenaria ursina, Castilleja
cinerea, and Eriogonum kennedyi var. austromontanum
Total area (ac
Unit or subunit Landowner\1\ (ha))
1A................................ USFS................ 69 (28)
1B................................ USFS................ 229 (93)
2A................................ USFS................ 21 (9)
2B................................ USFS................ 6 (2)
3A................................ USFS................ 58 (23)
3B................................ USFS................ 255 (103)
Private (The 71 (29) Wildlands
Conservancy).
4A................................ USFS................ 15 (6)
4B................................ USFS................ 24 (10)
4C................................ USFS................ 2 (1)
5A................................ USFS................ 62 (25)
5B................................ USFS................ 43 (17)
5C................................ USFS................ 0.2 (0.1)
6A................................ USFS................ 22 (9)
Private............. 6 (2)
6B................................ USFS................ 44 (18)
7A................................ USFS................ 320 (129) [[Page 67721]]
7B................................ CDFG................ 4 (2)
8A................................ USFS................ 15 (6)
Private............. 30 (12)
8B................................ Private............. 5 (2)
9................................. USFS................ 26 (10)
10................................ USFS................ 23 (9)
11A............................... USFS................ 127 (51)
11B............................... USFS................ 34 (14)
Total......................... .................... 1,511 (611)
\1\ USFS = U.S. Forest Service (lands in the San Bernardino National Forest), CDFG = California Department of Fish and Game.
Table 4.Units or Subunits and Total Area (acres (ac), hectares (ha))
Being Proposed as Critical Habitat for Arenaria ursina, Castilleja
cinerea, and Eriogonum kennedyi var. austromontanum
Total area (ac
Species Unit or subunits (ha))*
Arenaria ursina................ All except 4C, 5C, 1,478 (598) 7B, 9.
Castilleja cinerea............. All................... 1,511 (611)
Eriogonum kennedyi var. All except 2A, 3B, 4C, 970 (393) austromontanum. 5C, 7B, 9, 11A, 11B.
* These species often occur in the same pebble plains. Therefore the
total area being proposed as critical habitat for each species will
not equal the total area being proposed for all three species combined.
Unit Descriptions
We present brief descriptions of all units and subunits below and reasons why they meet the definition of critical habitat for Arenaria ursina, Castilleja cinerea, and Eriogonum kennedyi var. austromontanum. Each subunit is named using the pebble plain occurrence number (for example ``ppn. 100'') as identified in the USFS's 2002 Pebble Plain Management Guide.
Unit 1: Arrastre/Union Flat
The Arrastre/Union Flat pebble plain complex consists of 33 pebble plains of varying size that total approximately 377 ac (153 ha) of habitat, the majority of which are on the San Bernardino National Forest (SBNF) land (USFS 2002, pp. 32, 47). Pebble plains in this complex have historically been, and continue to be, impacted by vehicle use related to woodcutting and camping activities not authorized by the USFS (USFS 2002, p. 47). Pebble plains in this complex are also threatened by the invasion of nonnative cheatgrass (USFS 2002, pp. 47 48).
We are proposing to designate as critical habitat approximately 298 ac (121 ha) within this complex consisting of two pebble plains in the
FOR FURTHER INFORMATION CONTACT
Jim Bartel, Field Supervisor, Carlsbad Fish and Wildlife Office, at the address or telephone number listed under ADDRESSES. Persons who use a telecommunications device for the deaf (TDD) may call the Federal Information Relay Service (FIRS) at 8008778339, 24 hours a day, 7 days a week.