Endangered and Threatened Wildlife and Plants; Proposed Revised Critical Habitat for Brodiaea filifolia, 64930-64982 [E9-28869]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 74, Number 234 (Tuesday, December 8, 2009)]
[Proposed Rules]
[Pages 64930-64982]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-28869]



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Part IV





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; Proposed Revised 
Critical Habitat for Brodiaea Filifolia (Thread-Leaved Brodiaea); 
Proposed Rule

Federal Register / Vol. 74, No. 234 / Tuesday, December 8, 2009 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R8-ES-2009-0073]
[92210-1117-0000-B4]
RIN 1018-AW54


Endangered and Threatened Wildlife and Plants; Proposed Revised 
Critical Habitat for Brodiaea filifolia (thread-leaved brodiaea)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
revise designated critical habitat for Brodiaea filifolia (thread-
leaved brodiaea) under the Endangered Species Act of 1973, as amended 
(Act). Approximately 3,786 acres (ac) (1,532 hectares (ha)) of habitat 
fall within the boundaries of the proposed revised critical habitat 
designation, which is located in Los Angeles, San Bernardino, 
Riverside, Orange, and San Diego Counties in southern California.

DATES: We will accept comments received or postmarked from all 
interested parties on or before February 8, 2010. We must receive 
requests for public hearings, in writing, at the address shown in the 
FOR FURTHER INFORMATION CONTACT section by January 22, 2010.

ADDRESSES: You may submit comments by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov. 
Follow the instructions for submitting comments to Docket No. FWS-R8-
ES-2009-0073.
     U.S. mail or hand-delivery: Public Comments Processing, 
Attn: FWS-R8-ES-2009-0073; Division of Policy and Directives 
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, 
Suite 222; Arlington, VA 22203.
    We will not accept e-mail or faxes. We will post all comments on 
https://www.regulations.gov. This generally means that we will post any 
personal information you provide us (see the Public Comments section 
below for more information).

FOR FURTHER INFORMATION CONTACT: For general information on the 
proposed designation, contact Jim Bartel, Field Supervisor, U.S. Fish 
and Wildlife Service, Carlsbad Fish and Wildlife Office, 6010 Hidden 
Valley Road, Suite 101, Carlsbad, CA 92011; telephone (760) 431-9440; 
facsimile (760) 431-5901. If you use a telecommunications device for 
the deaf (TDD), call the Federal Information Relay Service (FIRS) at 
(800) 877-8339.

SUPPLEMENTARY INFORMATION:

Public Comments

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments or information from the public, other concerned government 
agencies, the scientific community, industry, or other interested party 
concerning this proposed rule. We particularly seek comments 
concerning:
    (1) The reasons why we should or should not revise the designation 
of habitat as ``critical habitat'' under section 4 of the Endangered 
Species Act of 1973, as amended (Act; 16 U.S.C. 1531 et seq.), 
including whether there are threats to the species from human activity, 
the degree of which can be expected to increase due to the designation, 
and whether that increase in threat outweighs the benefit of 
designation such that the designation of critical habitat is not 
prudent.
    (2) Specific information on:
     Areas that provide habitat for Brodiaea filifolia that we 
did not discuss in this proposed revised critical habitat rule,
     Areas within the geographical area occupied by the species 
at the time of listing containing the features essential to the 
conservation of B. filifolia that we should include in the designation 
and why,
     Areas outside the geographical area occupied by the 
species at the time of listing that are essential for the conservation 
of the species and why, and
     Any areas identified in this proposed revised critical 
habitat rule that should not be proposed as critical habitat and why.
     (3) Land-use designations and current or planned activities in the 
areas proposed as critical habitat, and their possible impacts on 
proposed critical habitat.
    (4) Comments or information that may assist us in identifying or 
clarifying the primary constituent elements (PCEs).
    (5) How the proposed revised critical habitat boundaries could be 
refined to more closely circumscribe the areas meeting the definition 
of critical habitat.
    (6) Any probable economic, national security, or other relevant 
impacts of designating any area that may be included in the final 
designation. We are particularly interested in any impacts on small 
entities or families, and the benefits of including or excluding areas 
that exhibit these impacts.
     (7) Whether lands in any specific subunits being proposed as 
critical habitat should be considered for exclusion under section 
4(b)(2) of the Act by the Secretary, and whether the benefits of 
potentially excluding any particular area outweigh the benefits of 
including that area as critical habitat.
     (8) The Secretary's consideration to exercise his discretion under 
section 4(b)(2) of the Act to exclude lands proposed in Subunits 11a, 
11b, 11c, 11d, 11e, 11f, 11g, and 11h that are within the area 
addressed by the Western Riverside County Multiple Species Habitat 
Conservation Plan (Western Riverside County MSHCP), and whether such 
exclusion is appropriate and why.
     (9) The Secretary's consideration to exercise his discretion under 
section 4(b)(2) of the Act to exclude lands proposed in Subunits 4b, 
4c, and 4g that are within the area addressed by the Orange County 
Southern Subregion Habitat Conservation Plan (Orange County Southern 
Subregion HCP), and whether such exclusion is appropriate and why.
     (10) The Secretary's consideration to exercise his discretion 
under section 4(b)(2) of the Act to exclude lands proposed in Subunits 
7a, 7b, 7c, and 7d that are within the area addressed by the City of 
Carlsbad's Habitat Management Plan (Carlsbad HMP) under the 
Northwestern San Diego County Multiple Habitat Conservation Plan 
(MHCP), and whether such exclusion is appropriate and why.
     (11) The Secretary's consideration to exercise his discretion 
under section 4(b)(2) of the Act to exclude lands proposed in Unit 12 
that are within the area addressed by the County of San Diego Subarea 
Plan and the City of San Diego Subarea Plan under the San Diego 
Multiple Species Conservation Plan (MSCP), and whether such exclusion 
is appropriate and why.
    (12) Special management considerations or protection that the 
physical and biological features essential to the conservation of the 
species may require.
     (13) Information on any quantifiable economic costs or benefits of 
the proposed revised designation of critical habitat.
     (14) Information on the currently predicted effects of climate 
change on Brodiaea filifolia and its habitat.
    (15) Whether we could improve or modify our approach to designating 
critical habitat in any way to provide for greater public participation 
and

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understanding, or to better accommodate concerns and comments.
    Our final determination concerning critical habitat for Brodiaea 
filifolia will take into consideration all written comments and any 
additional information we receive during the comment period. These 
comments are included in the public record for this rulemaking and we 
will fully consider them in the preparation of our final determination. 
On the basis of public comments, we may, during the development of our 
final determination, find that areas within the proposed designation do 
not meet the definition of critical habitat, that some modifications to 
the described boundaries are appropriate, or that areas may or may not 
be appropriate for exclusion under section 4(b)(2) of the Act.
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in the ADDRESSES section. We will not 
consider comments sent by e-mail or fax or to an address not listed in 
the ADDRESSES section.
    If you submit a comment via https://www.regulations.gov, your entire 
comment--including your personal identifying information--will be 
posted on the Web site. If you submit a hardcopy comment that includes 
personal identifying information, you may request at the top of your 
document that we withhold this information from public review. However, 
we cannot guarantee that we will be able to do so.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on https://www.regulations.gov, or by 
appointment, during normal business hours, at the U.S. Fish and 
Wildlife Service, Carlsbad Fish and Wildlife Office (see FOR FURTHER 
INFORMATION CONTACT).

Background

    It is our intent to discuss only those topics directly relevant to 
the proposed revision of critical habitat for Brodiaea filifolia. This 
proposed rule incorporates new information on family placement 
(biological taxonomic classification) and the distribution of B. 
filifolia that we did not discuss in the 2005 final critical habitat 
designation for this plant. No new information pertaining to the 
species' life history, ecology, or habitat was received following the 
2005 final critical habitat designation. A summary of topics that are 
relevant to this proposed revised critical habitat is provided below. 
For more information on B. filifolia, refer to the final listing rule 
published in the Federal Register on October 13, 1998 (63 FR 54975), 
and the designation of critical habitat for B. filifolia published in 
the Federal Register on December 13, 2005 (70 FR 73820). Additionally, 
more information on this species can be found in the five-year review 
for B. filifolia signed on August 13, 2009, which is available on our 
Web site at:  http//:www.fws.gov/Carlsbad.

Species Description

    Brodiaea filifolia is a perennial herb with dark-brown, fibrous-
coated corms (underground, bulb-like storage stem). Corms function 
similarly to bulbs such that they store water and nutrients during the 
dormant season (Smith 1997, p. 28). The flower stalks (scapes) are 8 to 
16 inches (in) (20 to 40 centimeters (cm)) tall. The leaves are basal, 
narrow, and shorter than the stalk, and the flowers are arranged in a 
loose umbel (all flowers are attached to the stalk at the same place 
and then radiate outward). Violet flowers start as tubes and then break 
into six spreading perianth (collective term for sepals and petals) 
segments that are 0.4 to 0.5 in (9 to 12 millimeters (mm)) long. The 
broad and notched anthers are 0.1 to 0.2 in (3 to 5 mm) long, and the 
fruit is a capsule (Munz 1974, pp. 877-878; Keator 1993, pp. 1180, 
1182; 63 FR 54975, p. 54976). Brodiaea filifolia can be distinguished 
from other species of Brodiaea that occur within its range (B. orcuttii 
(Orcutt's brodiaea), B. jolonensis (Mesa brodiaea), B. santarosae 
(Santa Rosa basalt brodiaea), and B. terrestris ssp. kernensis (dwarf 
brodiaea)) by its narrow, pointed staminodia (characteristic sterile 
stamens), short filament (flower part attaching the fertile anthers to 
the perianth), spreading perianth segments (saucer-shaped flower), and 
a thin perianth tube, which is subsequently split by developing fruit 
(Niehaus 1971, p. 37; Munz 1974, pp. 877-878; Chester et al. 2007, pp. 
191-196).

Species Biology and Life History

    The annual growth cycle of Brodiaea filifolia begins in fall when 
the first rains break the summer dormancy of the underground corm 
(Niehaus 1971, p. 4; Keator 1993, p. 1180). The leaves reach their full 
length during February and March (Niehaus 1971, p. 5). A solitary 
flower stalk grows from the corm in March or April and the flower 
period extends from late April to early June (CNPS 2001, p. 99; Niehaus 
1971, pp. 7-9). In some years, only a few flowers bloom within an 
occurrence; during other years, several thousand flowers can be found 
in the larger occurrences.
    In the summer months, the seed capsules of Brodiaea filifolia 
mature. The seeds are released and fall to the ground, either on the 
surface or into cracks in the soil. During fall and winter rains, the 
clay matrix hydrates, softens, and expands, which causes the cracks to 
close; following this soil hydration period, seedlings emerge with 
leaves and a specialized root. Seedlings of B. filifolia are equipped 
with a specialized, succulent contractile root that is lost by mature 
corms and facilitates the seasonal downward movement of the young plant 
(Niehaus 1971, p. 4). The contractile root swells with moisture in the 
wet season, creating space below the developing cormlet. As the soil 
dries, the contractile root dries and shrinks longitudinally, drawing 
the young cormlet downward in the soil. This process continues to a 
point at which the soil moisture is adequate to keep the contractile 
root from shrinking, resulting in the location of the corm in the 
appropriate soil horizon for survival. Cormlets produced annually from 
existing older corms also produce contractile roots that draw them 
laterally away from the parent corm (Niehaus 1971, p. 4).
    Brodiaea filifolia reproduces vegetatively by producing 
``cormlets'' that break off from the mature corms, and sexually by 
producing seeds (Niehaus 1971, p. 4). All species of Brodiaea examined 
to date are self-incompatible, meaning they are incapable of producing 
seeds with pollen from flowers on the same plant or from flowers of 
plants with the same allele (or different form of a gene) at the self-
incompatibility gene locus/loci (Niehaus 1971, p. 27). Therefore, 
cross-pollination from plants of the same species but with different 
alleles at this locus is necessary for successful reproduction to occur 
(Niehaus 1971, p. 27). Upon maturity, three segments of the vertically 
oriented capsules split apart, revealing many small (0.08 to 0.10 in 
long; 2 to 2.5 mm long) black seeds (Munz 1974, p. 878). The seeds are 
then dispersed as wind rattles the capsules (Smith 1997, p. 29). 
Dispersal of seeds from an individual is likely localized, leading to 
patches of plants with the same self-incompatible alleles. This means 
that effective pollination for seed set requires the maintenance of 
pollinator habitat and dispersal corridors. The vegetative reproduction 
of small cormlets by the corm allows individual plants to reproduce 
vegetatively; however, sexual reproduction by seeds is necessary to 
continue the process of sexual selection and evolution. Active 
pollinators in and

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around occurrences of Brodiaea filifolia assure that the flowers will 
be pollinated and that viable seeds will be produced. Therefore, 
supporting and maintaining pollinators and pollinator habitat is 
essential for the long-term conservation of B. filifolia (Niehaus 1971, 
p. 27).

Habitat

    As described in the listing rule (October 13, 1998; 63 FR 54975, 
pp. 54976-54977), Brodiaea filifolia typically occurs on gentle 
hillsides, valleys, and floodplains within mesic (moderately moist), 
southern needlegrass grassland and alkali grassland plant communities 
that are associated with clay, loamy sand, or alkaline silty-clay soils 
(California Department of Fish and Game (CDFG) 1981, p. 3; Bramlet 
1993, pp. 6-7). Sites occupied by this species are frequently 
intermixed with (or near) coastal sage scrub, chaparral, or vernal pool 
habitat (63 FR 54975, p. 54976).
    We refined the description of suitable habitat in the 2005 final 
rule designating critical habitat for Brodiaea filifolia (70 FR 73820; 
December 13, 2005) in response to comments we received from peer 
reviewers. We stated that this species is usually found in herbaceous 
plant communities such as valley needlegrass grassland, valley sacaton 
grassland, nonnative grassland, alkali playa, southern interior basalt 
vernal pools, San Diego mesa hardpan vernal pools, and San Diego mesa 
claypan vernal pools (Holland 1986, pp. 34-37, 41, 44). Brodiaea 
filifolia also grows in open areas in shrub-dominated coastal sage 
scrub ecosystems (70 FR 73820, p. 73837). The herbaceous communities 
that B. filifolia is a part of occur in open areas on clay soils, soils 
with a clay subsurface, or clay lenses within loamy, silty loam, loamy 
sand, silty deposits with cobbles or alkaline soils, ranging in 
elevation from 100 feet (ft) (30 meters(m)) to 2,500 ft (765 m), 
depending on soil series. These soils facilitate the natural process of 
seed dispersal and germination, cormlet disposition or movement to an 
appropriate soil depth, and corm persistence through seedling and adult 
phases of flowering and fruit set (70 FR 73820, p. 73837).

Spatial Distribution and Historical Range

    The historical range of Brodiaea filifolia extends from the 
foothills of the San Gabriel Mountains in the City of Glendora (Los 
Angeles County), east to Arrowhead Hot Springs in the western foothills 
of the San Bernardino Mountains (San Bernardino County), and south 
through eastern Orange and western Riverside Counties to Rancho Santa 
Fe in central coastal San Diego County, California (California Natural 
Diversity Database (CNDDB) 2007).
    At the time of listing in 1998, 46 historical occurrences of 
Brodiaea filifolia were reported (63 FR 54975, p. 54977). Nine of these 
occurrences, most from San Diego County, were considered extirpated, 
leaving 37 occurrences presumed extant at the time of listing. Eight 
documented extant occurrences were not accounted for in the final 
listing rule because we lacked specific data on these occurrences. In 
our 2009 5-year review of B. filifolia, we reassessed the occurrence 
data on this species. Due to the discovery of new occurrences, 
regrouping of occurrences, and the extirpation of 3 occurrences after 
listing, we concluded in the 5-year review that there are now 68 extant 
(or presumed extant) occurrences of B. filifolia. Most importantly to 
our reassessment of this species were 23 additional occurrences 
detected within the known range of the species following the 1998 
listing. The identification of these new occurrences was a result of 
surveys conducted in locations that had not been surveyed prior to 
1998. These 23 occurrences are located in the following areas: (1) Four 
occurrences are in Orange County at Trampas Canyon, Middle Gabino, East 
Talega, and Prima Deshecha landfill; (2) ten occurrences are in San 
Diego County on Marine Corps Base Camp Pendleton (MCB Camp Pendleton); 
(3) seven occurrences are in San Diego County (outside of MCB Camp 
Pendleton) in the City of Oceanside (Arbor Creek, Vista Pacific, Buena 
Vista Creek Preserve), City of Carlsbad (Calavera Village H, Carlsbad 
Oaks), City of San Marcos (Oleander site), and at Artesian Trails near 
4S Ranch; and (4) two occurrences are in Riverside County along the San 
Jacinto River at the intersection of San Jacinto Avenue and Dawson 
Road, and on the Santa Rosa Plateau at Corona Cala Camino.
    For the purpose of this proposed revised critical habitat, we 
consider the areas where Brodiaea filifolia has been found since 
listing to be within the geographical area occupied by the species at 
the time of listing (1998). As with many species, greater efforts to 
conduct surveys may result in a greater number of known occurrences 
being identified (Ferren et al. 1995). The 23 new occurrences are all 
in relative proximity and in similar habitats to occurrences that were 
known at the time of listing. Additionally, B. filifolia is thought to 
have limited dispersal capabilities and is limited to specific habitat 
types making it unlikely that new occurrences are frequently 
established. Most of the new occurrences found since listing have 
population sizes of more than 1,000 plants, indicating that they were 
not recently established since it would take several years for an 
occurrence from a limited number of dispersing seeds to reach a 
population of this size. Therefore, we believe that all known 
occurrences of B. filifolia are within the geographical area occupied 
at the time this species was listed under the Act. Furthermore, 
additional translocated occurrences (occurrences moved from one 
location to another) are also within the geographical area occupied by 
the species at the time of listing.

Abundance

    The size of each Brodiaea filifolia population is often measured by 
counting numbers of standing flower stalks. Because many B. filifolia 
corms do not produce flowering stalks each year, this method of 
counting may result in a number of vegetative plants and corms going 
undetected in surveys (Taylor and Burkhart 1992, pp. 1-7; Morey 1995, 
p. 2; Vinje 2008, pers. comm.). For this reason, any number of 
individuals observed at a site should be considered an estimate of the 
minimum number of plants present. We consider these estimates useful in 
comparing the relative abundance of B. filifolia at various sites 
across the species' range because these numbers provide an approximate 
measure of the size of the occurrence.
    Some researchers have conducted studies to provide data on the 
ratio of flowering stalks to the actual number of individual Brodiaea 
filifolia plants that may be present at a site. A field study at the 
Santa Rosa Plateau Ecological Reserve revealed an 8:1 ratio of non-
flowering corms to flowering plants (12.5 percent flowered) (Morey 
1995, p. 2). At a residential development site in the City of Carlsbad, 
only 20 plants (0.25 percent) flowered, where 8,000 corms were later 
located (Taylor and Burkhart 1992, pp. 1-7). In 2007--a dry year--Vinje 
(2008, pers. comm.) reported that 14,373 vegetative B. filifolia plants 
were counted within three research plots at the Rancho La Costa 
occurrence in Carlsbad, but none of the plants flowered (Vinje 2008, 
pers. comm.). Even in a wet year, only 2 to 26 percent of the plants 
within the plots at Rancho La Costa flowered (Vinje 2008, pers. comm.). 
In this proposed revised critical habitat, we are using the number of 
flowering stalks at each site (i.e., the maximum recorded number) as a 
relative measure of the occurrence's

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size rather than an absolute measure of the occurrence size. In that 
context, the existing plant count data is useful in comparing the 
relative size of different occurrences to one another.
    To date, no systematic surveys of all known occurrences of Brodiaea 
filifolia have been conducted. There is little consistent range-wide 
information about abundance or population trends in B. filifolia. 
Current estimates suggest that the majority of B. filifolia occurrences 
contain 2,000 or fewer individuals (Service 2009, pp. 8-13). The areas 
containing the largest occurrences (3,000 or more) are at the following 
locations: San Dimas in Los Angeles County; Santa Rosa Plateau 
Ecological Reserve, San Jacinto Wildlife Area, Case Road, and Railroad 
Canyon in Riverside County; Aliso and Wood Canyon Wilderness Park, and 
Cristianitos Canyon in Orange County; and Upham, Oleander/San Marcos 
Elementary, Rancho Carrillo, Letterbox Canyon, Rancho La Costa, and 
Taylor/Darwin in San Diego County.

Taxonomy and Family Placement - Movement of Brodiaea From Liliaceae 
(Lily Family) to Themidaceae (Cluster Lily Family)

    The name and description of Brodiaea filifolia have not changed 
since listing under the Act. However, as described below, the family in 
which the plant is placed has changed from Liliaceae (lily family) to 
Themidaceae (cluster lily family). Additionally, plants that were 
previously identified as hybrids and not pure B. filifolia have now 
been described as a new species, B. santarosae. Pires (2007, p. 1) and 
Preston (2007, pers. comm.) intend to include Brodiaea santarosae as a 
separate species in their treatment of the genus Brodiaea for the 
revision of the Jepson Manual that is in progress; this is based on 
their assessment of Chester et al. (2007, pp. 187-198). The following 
text describes movement of the genus Brodiaea from Liliaceae to 
Themidaceae.
    When we listed Brodiaea filifolia as a threatened species on 
October 13, 1998 (63 FR 54975), it was considered part of a large and 
broadly defined family known as Liliaceae. Brodiaea and several other 
genera including Bloomeria, Dichelostemma, Triteleia, and Allium 
historically were placed in the Amaryllidaceae (amaryllis family) or 
the Liliaceae based on perceived importance of characters related to 
the position of the ovary or the inflorescence type. Salisbury (1866) 
recognized a group of several genera that includes taxa now named 
Brodiaea as a family, which was distinct from Allium and other genera 
in the Liliaceae, and subsequently named the new family Themidaceae 
(Salisbury 1866, pp. 84-87). Recent molecular and anatomical studies 
support recognition of Salisbury's Themidaceae family. First, Fay and 
Chase (1996, pp. 441-451) present evidence that several genera, 
including Triteleia, Brodiaea, Bloomeria, and Dichelostemma, form a 
distinct group for which the earliest name available for this group at 
the family rank is Themidaceae. Second, genera in the Themidaceae share 
a common ancestor (the included members are termed monophyletic) that 
is supported by phylogenetic analyses of morphological data and plastid 
DNA sequences (Pires et al. 2001, pp. 601-626; Pires and Sytsma 2002, 
pp. 1342-1359). Genetic and morphological analysis of members of the 
Themidaceae, as described by Salisbury and other related groups, 
support the placement of the genus Brodiaea into the Themidaceae (Pires 
et al. 2001, pp. 610-626).
    Brodiaea is retained in the family Liliaceae in the recent Flora of 
North America (Pires 2002, p. 321); however, the author of the family 
description (Utech 2002, p. 52) includes a table that lists Brodiaea as 
a member of the Themidaceae and states that the available evidence 
strongly supports dismemberment of the Liliaceae. The family 
Themidaceae, including Brodiaea, will be recognized as a family 
separate from Liliaceae in the upcoming revision of the Jepson Manual 
(Pires 2007, p. 1; Preston 2007, pers. comm.). We have reviewed this 
material and we are in agreement with the change from Liliaceae to 
Themidaceae. As part of this rule, we propose to amend part 17, 
subchapter B of chapter I, title 50 of the Code of Federal Regulations 
to reflect the transfer of B. filifolia from Liliaceae to Themidaceae. 
This transfer does not alter the definition or distribution of B. 
filifolia.

Previous Federal Actions

    We published our final designation of critical habitat for Brodiaea 
filifolia on December 13, 2005 (70 FR 73820). The Center for Biological 
Diversity filed a complaint in the U.S. District Court for the Southern 
District of California on December 19, 2007, challenging our 
designation of critical habitat for B. filifolia and Navarretia 
fossalis (Center for Biological Diversity v. United States Fish and 
Wildlife, et al., Case No. 07-CV-02379-W-NLS). In a settlement 
agreement dated July 25, 2008, we agreed to reconsider the critical 
habitat designation for B. filifolia. The settlement stipulated that 
the Service shall submit a proposed revised critical habitat 
designation for B. filifolia to the Federal Register by December 1, 
2009, and submit a final revised critical habitat designation to the 
Federal Register by December 1, 2010.

Critical Habitat

    Critical habitat is defined in section 3 of the Act as:
    (1) 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
    (a) essential to the conservation of the species and
    (b) which may require special management considerations or 
protection; and
     (2) Specific areas outside the geographical area occupied by 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 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, transplantation, and, in the extraordinary case where 
population pressures within a given ecosystem cannot otherwise be 
relieved, may include regulated taking.
    Critical habitat receives protection under section 7(a)(2) of the 
Act through the prohibition against Federal agencies carrying out, 
funding, or authorizing activities that are likely to result in the 
destruction or adverse modification of critical habitat. Section 
7(a)(2) 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 
non-Federal landowners. Where a landowner seeks or requests Federal 
agency funding or authorization for an action that may affect a listed 
species or critical habitat, the consultation requirements of section 
7(a)(2) of the Act would apply, but even in the event

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of a destruction or adverse modification finding, the Federal action 
agency's and the applicant'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 geographical area occupied by the species at the time of listing 
must contain physical and biological 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 and commercial data available, habitat areas supporting the 
essential physical or biological features that provide essential life 
cycle needs of the species; that is, areas on which are found the 
primary constituent elements (PCEs) laid out in the appropriate 
quantity and spatial arrangement essential to the conservation of the 
species. Under the Act and regulations at 50 CFR 424.12, we can 
designate critical habitat in areas outside the geographical area 
occupied by the species at the time it is listed only when we determine 
that those areas are essential for the conservation of the species and 
that designation limited to the species' present range would be 
inadequate to ensure 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 designated as 
critical habitat, our primary source of information is generally the 
information developed during the listing process for the species. 
Additional information sources may include the recovery plan for the 
species, articles in peer-reviewed journals, conservation plans 
developed by States and counties, scientific status surveys and 
studies, biological assessments, or other unpublished materials and 
expert opinion or personal knowledge.
    Habitat is often dynamic, and species may move from one area to 
another over time. In particular, we recognize that climate change may 
cause changes in the arrangement of occupied habitat patches. Current 
climate change predictions for terrestrial areas in the Northern 
Hemisphere indicate warmer air temperatures, more intense precipitation 
events, and increased summer continental drying (Field et al. 1999, pp. 
1-3; Hayhoe et al. 2004, p. 12422; Cayan et al. 2005, p. 6; 
Intergovernmental Panel on Climate Change 2007, p. 11; Cayan et al. 
2009, p. xi). Additionally, the southwestern region of the country is 
predicted to become drier and hotter overall (Hayhoe et al. 2004, 
p.12424; Seager et al. 2007, p. 1181). Climate change may also affect 
the duration and frequency of drought and these climatic changes may 
become even more dramatic and intense (Graham 1997). Documentation of 
climate-related changes that have already occurred in California (Croke 
et al. 1998, pp. 2128, 2130; Brashears et al. 2005, p. 15144), and 
future drought predictions for California (e.g., Field et al. 1999, pp. 
8-10; Lenihen et al. 2003, p. 1667; Hayhoe et al. 2004, p. 12422; 
Brashears et al. 2005, p. 15144; Seager et al. 2007, p. 1181) and North 
America (IPCC 2007, p. 9) indicate prolonged drought and other climate-
related changes will continue in the foreseeable future.
    We anticipate these changes will affect Brodiaea filifolia habitat 
and occurrences. For example, if the amount and timing of precipitation 
or the average temperature increases in southern California, the 
following four changes may affect the long-term viability of B. 
filifolia occurrences in their current habitat configuration: (1) Drier 
conditions may result in a lower percent germination and smaller 
population sizes; (2) a shift in the timing of the annual rainfall may 
favor nonnative species that impact the quality of habitat for this 
species; (3) warmer temperatures may affect the timing of pollinator 
life-cycles causing pollinators to become out-of-sync with timing of 
flowering B. filifolia; and (4) drier conditions may result in 
increased fire frequency, making the ecosystems in which B. filifolia 
currently grows more vulnerable to the threats of subsequent erosion 
and nonnative/native plant invasion.
    At this time, we are unable to identify the specific ways that 
climate change will impact Brodiaea filifolia, therefore, we are unable 
to determine what additional areas, if any, may be appropriate to 
include in the proposed revised critical habitat for this species. We 
specifically request information from the public on the currently 
predicted effects of climate change on B. filifolia and its habitat. 
Additionally, 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 support occurrences, but are outside the critical 
habitat designation, will continue to be subject to conservation 
actions we and other Federal agencies implement under section 7(a)(1) 
of the Act. They 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 new information available to 
these planning efforts calls for a different outcome.

Methods

    As required by section 4(b) of the Act, we used the best scientific 
and commercial data available in determining which areas within the 
geographic area occupied by the species at the time of listing contain 
the features essential to the conservation of Brodiaea filifolia, and 
which areas outside the geographical area occupied at the time of 
listing are essential for the conservation of B. filifolia. We reviewed 
the 2005 final critical habitat designation for B. filifolia (70 FR 
73820), information from state, Federal, and local government agencies, 
and information from academia and private organizations that collected 
scientific data on the species. We also used the information provided 
in the 5-year review for B. filifolia (Service 2009, pp. 1-47). Other 
information we used for this proposed revised critical habitat

[[Page 64935]]

includes: CNDDB (CNDDB 2009, pp. 1-73); data and information included 
in reports submitted during consultations under section 7 of the Act; 
information contained in analyses for individual and regional HCPs 
where B. filifolia is a covered species; data collected on MCB Camp 
Pendleton; data collected from reports submitted by researchers holding 
recovery permits under section 10(a)(1)(A) of the Act; information 
received from local species experts; published and unpublished papers, 
reports, academic theses, or surveys; Geographic Information System 
(GIS) data (such as species occurrence data, soil data, land use, 
topography, aerial imagery, and ownership maps); and correspondence to 
the Service from recognized experts. We are not currently proposing any 
areas as critical habitat that are outside the geographical area 
occupied by the species at the time of listing because we have 
determined that we can conserve this species by including in critical 
habitat a subset of areas that were occupied at the time of listing (28 
of 68 occurrences known to be occupied are proposed as critical 
habitat).

Physical and Biological Features

    In accordance with section 3(5)(A)(i) and 4(b)(1)(A) of the Act and 
regulations at 50 CFR 424.12(b), in determining which areas within the 
geographical area occupied at the time of listing to propose as revised 
critical habitat, we consider those physical and biological features 
that are essential to the conservation of the species and which may 
require special management considerations or protection. We consider 
the essential physical and biological features to be the PCEs laid out 
in the appropriate quantity and spatial arrangement essential to the 
conservation of the species. The PCEs 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 historical, geographical, and ecological 
distributions of a species.
    We derive the PCEs required for Brodiaea filifolia from its 
biological needs. The areas included in our proposed revised critical 
habitat for B. filifolia contain the appropriate soils and associated 
vegetation at suitable elevations, and adjacent areas necessary to 
maintain associated physical processes such as a suitable hydrological 
regime. The areas provide suitable habitat, water, minerals, and other 
physiological needs for reproduction and growth of B. filifolia, as 
well as habitat that supports pollinators of B. filifolia. The PCEs and 
the resulting physical and biological features essential to the 
conservation of B. filifolia are derived from studies of this species' 
habitat, ecology, and life history as described in the Background 
section of this proposed rule, and the previous critical habitat rule 
(70 FR 73820; December 13, 2005), and in the final listing rule (63 FR 
54975; October 13, 1998).
Space for Individual and Population Growth, and for Normal Behavior
    Habitats that provide space for growth and persistence of Brodiaea 
filifolia include areas: (1) With combinations of appropriate elevation 
and clay or clay-associated soils, on mesas or low to moderate slopes 
that support open native or annual grasslands within open coastal sage 
scrub or coastal sage scrub-chaparral communities; (2) in floodplains 
or in association with vernal pool or playa complexes that support 
various grassland or scrub communities; (3) on soils derived from 
olivine basalt lava flows on mesas and slopes that support vernal pools 
within grassland, oak woodland, or savannah communities; or (4) on 
sandy loam soils derived from basalt and granodiorite parent material 
with deposits of cobbles and boulders supporting intermittent seeps, 
and open marsh communities. Despite the wide range of habitats where B. 
filifolia occurs, this species occupies a specific niche of habitat 
that is moderately wet to occasionally wet.
Food, Water, Air, Light, Minerals, or Other Nutritional or 
Physiological Requirements
    All members of the genus Brodiaea require full sun and many tend to 
occur on only one or a few soil series (Niehaus 1971, pp. 26-27). 
Brodiaea filifolia occurs on several formally named soil series, but 
these are all primarily clay soils with varying amounts of sand and 
silt. In this proposed rule, we listed all the mapped soils that 
overlap with the distribution of B. filifolia. Sometimes clay soils 
occur as inclusions within other soil series, as such, we have named 
those other soil series in this rule. Another reason that there are 
many differently named soil series is because this species occurs in 
five counties, each of which has uniquely named soils. Despite the 
diversity in named soil series, B. filifolia is a clay soils endemic 
and always occurs on soils with a clay component.
    In San Diego, Orange, and Los Angeles Counties, occurrences of 
Brodiaea filifolia are highly correlated with specific clay soil series 
such as, but not limited to: Alo, Altamont, Auld, and Diablo or clay 
lens inclusions in a matrix of loamy soils such as Fallbrook, 
Huerhuero, and Las Flores series (63 FR 54975, p. 54978; CNDDB 2009, 
pp. 1-76; Service GIS data 2009). These soils generally occur on mesas 
and hillsides with gentle to moderate slopes, or in association with 
vernal pools. These soils are generally vegetated with open native or 
nonnative grassland, open coastal sage scrub, or open coastal sage 
scrub-chaparral communities. In San Bernardino County, the species is 
associated with Etsel family-Rock outcrop-Springdale and Tujunga-Urban 
land-Hanford soils (Service GIS data 2009). These soils are generally 
vegetated with open native and nonnative grasslands, open coastal sage 
scrub, or open coastal sage scrub-chaparral communities.
    In western Riverside County, the species is often found on alkaline 
silty-clay soil series such as, but not limited to, Domino, 
Grangeville, Waukena, and Willows underlain by a clay subsoil or 
caliche (a hardened gray deposit of calcium carbonate). These soils 
generally occur in low-lying areas and floodplains or are associated 
with vernal pool or playa complexes. These soils are generally 
vegetated with open native and nonnative grasslands, alkali grassland, 
or alkali scrub communities. Also in western Riverside County, the 
species is found on clay loam soils underlain by heavy clays derived 
from basalt lava flows (i.e., Murrieta series on the Santa Rosa 
Plateau) (Bramlet 1993, p. 1; CNDDB 2009, pp. 1-76; Service GIS data 
2009). These soils generally occur on mesas and gentle to moderate 
slopes or are associated with basalt vernal pools. These soils are 
vegetated with open native or nonnative grasslands or oak woodland 
savannah communities.
    In some areas in northern San Diego County and southwestern 
Riverside County, the species is found on sandy loam soils derived from 
basalt and granodiorite parent materials; deposits of gravel, cobble, 
and boulders; or hydrologically fractured, weathered granite in 
intermittent streams and seeps. These soils and deposits are generally 
vegetated by open riparian and freshwater marsh communities associated 
with intermittent drainages, floodplains, and seeps. Throughout B. 
filifolia's range these soils facilitate the natural process of seed 
dispersal and

[[Page 64936]]

germination, cormlet disposition or movement to an appropriate soil 
depth, and corm persistence through seedling and adult phases of 
flowering and fruit set described earlier.
Habitats That Are Protected From Disturbance or Are Representative of 
the Historical, Geographical, and Ecological Distributions of the 
Species
    The conservation of Brodiaea filifolia is dependent on several 
factors including, but not limited to, maintenance of areas of 
sufficient size and configuration to sustain natural ecosystem 
components, functions, and processes (such as full sun exposure, 
natural fire and hydrologic regimes, adequate biotic balance to prevent 
excessive herbivory); protection of existing substrate continuity and 
structure, connectivity among groups of plants within geographic 
proximity to facilitate gene flow among the sites through pollinator 
activity and seed dispersal; and sufficient adjacent suitable habitat 
for vegetative reproduction and population expansion.
    A natural, generally intact surface and subsurface soil structure, 
not permanently altered by anthropogenic land use activities (such as 
deep, repetitive discing, or grading), and associated physical 
processes such as a hydrological regime is necessary to provide water, 
minerals, and other physiological needs for Brodiaea filifolia. A 
natural hydrological regime includes seasonal hydration followed by 
drying out of the substrate to promote growth of plants and new corms 
for the following season. These conditions are also necessary for the 
normal development of seedlings and young vegetative cormlets.
Habitat for Pollinators of Brodiaea filifolia
    Cross-pollination is essential for the survival and recovery of 
Brodiaea filifolia because this species is self-incompatible and it 
cannot sexually reproduce without the aid of insect pollinators. A 
variety of insects are known to cross-pollinate Brodiaea species, 
including Tumbling Flower Beetles (Mordellidae, Coleoptera) and Sweat 
Bees (Halictidae, Hymenoptera; Niehaus 1971, p. 27). Bell and Rey 
(1991, p. 3) report that native bees observed pollinating B. filifolia 
on the Santa Rosa Plateau in Riverside County include Bombus 
californicus (Apidae, Hymenoptera), Hoplitus sp. (Megachilidae, 
Hymenoptera), Osmia sp. (Megachilidae, Hymenoptera), and an 
unidentified Anthophorid (digger-bee). Anthophoridae and Halictidae are 
important pollinators of Brodiaea filifolia, as shown at a study site 
in Orange County (Glenn Lukos Associates 2004, p. 3). Supporting and 
maintaining pollinators and pollinator habitat is essential for the 
conservation of B. filifolia because this species cannot set viable 
seed without cross-pollination.
    Of primary concern to the conservation of Brodiaea filifolia are 
solitary bees (such as sweat bees (Hoplitus sp. and Osmia sp.)) because 
these are the pollinators that have the most specific habitat 
requirements (such as nesting requirements) and are impacted by 
fragmentation and reduced diversity of natural habitats at a small 
scale (Gathmann and Tscharntke 2002, p. 757; Steffan-Dewenter 2003, p. 
1041; Shepherd 2009, pers. comm.). Due to the focused foraging habits 
of solitary bees we believe that these insects may be the most 
important to the successful reproduction of B. filifolia. To sustain an 
active pollinator community for B. filifolia, alternative pollen or 
food source plants may be necessary for the persistence of these 
insects when B. filifolia is not in flower. It is also necessary for 
nest sites for pollinators to be located within flying distance of B. 
filifolia occurrences.
    Bombus spp. (bumblebees) may also be important to the pollination 
of Brodiaea filifolia, however, these insects may be able to travel 
greater distances and cross fragmented landscapes to pollinate B. 
filifolia. In a study of experimental isolation and pollen dispersal of 
Delphinium nuttallianum (Nuttall's larkspur), Schulke and Waser (2001, 
pp. 242-243) report that adequate pollen loads were dispersed by 
bumblebees within control populations and in isolated experimental 
``populations'' from 164 to 1,312 feet (ft) (50 to 400 meters (m)) 
distant from the control populations. One of several pollinator taxa 
effective at 1,312 ft (400 m) was Bombus californicus (Schulke and 
Waser 2001, pp. 240-243), which was also one of four bee species 
observed pollinating Brodiaea filifolia by Bell and Rey (1991, p. 2). 
Studies by Steffan-Dewenter and Tscharntke (2000, p. 293) demonstrated 
that it is possible for bees to forage as far as 4,920 ft (1,500 m) 
from a colony, and at least one study suggests that bumblebees may 
forage many kilometers away (Sudgen 1985, p. 308). Bumblebees may be 
effective at transferring pollen between occurrences of B. filifolia 
because they are larger and have been found pollinating plants at 
distances of 1,312 to 4,920 ft (400 to 1500 m). However, the visits and 
focused effort of bumblebees may be less frequent than ground-nesting 
bees.
    Ground-nesting solitary bees appear to have limited dispersal and 
flight abilities (Thorp and Leong 1995, p. 7). Studies have shown that 
as areas are fragmented by development, remaining habitat areas have 
reduced pollinator diversity (Steffan-Dewenter 2003, p. 1041). If 
pollinators are eliminated from an occurrence, Brodiaea filifolia will 
no longer be able to reproduce sexually. Of the native bees that have 
been observed pollinating B. filifolia, solitary ground-nesting bees 
are the most sensitive to habitat disturbance and the most likely to be 
lost from an area. Sweat bees (family Halictidae), Holitus (family 
Magachilidea), and Osmia (mason bees, family Megachilidea), fly 
approximately 900 to 1,500 ft (274 to 457 m), 600 to 900 ft (183 to 274 
m), and 600 to 1,800 ft (183 to 549 m), respectively (Shepherd 2009, 
pers. comm.). Bombus californicus (family Apidae) and Digger bees 
(family Apidae) fly further, generally more than over 2,640 ft (804 m) 
(Shepherd 2009, pers. comm.). These flight distances are important in 
determining what habitat associated with Brodiaea filifolia occurrences 
provides habitat for this species' pollinators. Conserving habitat 
where these pollinators nest and forage will sustain an active 
pollinator community and provide for the cross-pollination of B. 
filifolia.
    In our review of the data on pollinators of Brodiaea filifolia in 
the 2005 critical habitat rule, we determined that an 820-ft (250-m) 
area around each occurrence identified in the critical habitat would 
provide adequate space to support B. filifolia's pollinators. In the 
2005 critical habitat rule, we based the 820-ft (250-m) distance on a 
conservative estimate for the mean routine flight distance for bees. 
This distance represents an estimate of flight distance for pollinators 
that fly an average of less than 1,800 ft (549 m) (i.e., the maximum 
distance observed by known pollinators of B. filifolia except Bombus 
californicus). Research supports this distance, as studies looking at 
areas with a radius of 820 ft (250 m) have found that solitary bees 
forage at this scale and that if fragmentation occurs at this scale the 
presence of solitary bees will decrease (Steffan-Dewenter et al. 2002, 
pp. 1027-1029; Shepherd 2009, pers. comm.). Insects that travel greater 
distances than 1,800 ft (549 m) on average may also find habitat within 
820 ft (250 m) of Brodiaea filifolia occurrences. It is also possible 
that insects flying greater than 1,800 ft (549 m) are flying in from 
greater distances (Bombus californicus and Anthophora) and are living 
in habitats that are not directly connected with areas supporting 
Brodiaea filifolia.

[[Page 64937]]

Delineating a pollinator use area larger than 820 ft (250 m) around B. 
filifolia would capture habitat that may not directly contribute to the 
survival or recovery of B. filifolia. Including habitat out from the 
mapped occurrences of B. filifolia up to 820 ft (250m) in the PCEs is 
necessary to support pollinator activity in critical habitat, support 
the sexual reproduction of B. filifolia, and provide for gene flow, 
pollen dispersal, and seed dispersal.

Primary Constituent Elements for Brodiaea filifolia

    Pursuant to the Act and its implementing regulations, when 
considering the designation of critical habitat, we must focus on the 
primary constituent elements within the geographical area occupied by 
Brodiaea filifolia at the time of listing that are essential to the 
conservation of the species and may require special management 
considerations or protection. The essential physical and biological 
features are those PCEs laid out in an appropriate quantity and spatial 
arrangement determined to be essential to the conservation of the 
species. All areas proposed as revised critical habitat for B. 
filifolia are currently occupied, are within the geographical area 
occupied by the species at the time of listing, and contain sufficient 
PCEs to support at least one life- history function (see the ``Spatial 
Distribution and Historical Range'' section of this rule).
    Based on our current knowledge of the life history, biology, and 
ecology of Brodiaea filifolia, and the requirements of the habitat to 
sustain the life-history traits of the species, we determined that the 
PCEs specific to B. filifolia are:
    (1) PCE 1--Appropriate soil series at a range of elevations and in 
a variety of plant communities, specifically:
    (A) Clay soil series of various origins (such as Alo, Altamont, 
Auld, or Diablo), clay lenses found as unmapped inclusions in other 
soils series, or loamy soils series underlain by a clay subsoil (such 
as Fallbrook, Huerhuero, or Las Flores) occurring between the 
elevations of 100 and 2,500 ft (30 and 762 m).
    (B) Soils (such as Cieneba-rock outcrop complex and Ramona family-
Typic Xerothents soils) altered by hydrothermal activity occurring 
between the elevations of 1,000 and 2,500 ft (305 and 762 m).
    (C) Silty loam soil series underlain by a clay subsoil or caliche 
that are generally poorly drained, moderately to strongly alkaline, 
granitic in origin (such as Domino, Grangeville, Traver, Waukena, or 
Willows) occurring between the elevations of 600 and 1,800 ft (183 and 
549 m).
    (D) Clay loam soil series (such as Murrieta) underlain by heavy 
clay loams or clays derived from olivine basalt lava flows occurring 
between the elevations of 1,700 and 2,500 ft (518 and 762 m).
    (E) Sandy loam soils derived from basalt and granodiorite parent 
materials; deposits of gravel, cobble, and boulders; or hydrologically 
fractured, weathered granite in intermittent streams and seeps 
occurring between 1,800 and 2,500 ft (549 and 762 m).
     (2) PCE 2--Areas with a natural, generally intact surface and 
subsurface soil structure, not permanently altered by anthropogenic 
land use activities (such as deep, repetitive discing, or grading), 
extending out up to 820 ft (250 m) from mapped occurrences of Brodiaea 
filifolia.
    This proposed revision to the critical habitat designation is 
designed for the conservation of those areas containing PCEs necessary 
to support the species' life-history traits. All units/subunits of the 
proposed critical habitat contain one of the specific soil components 
identified in PCE 1 and have natural, generally intact surface and 
subsurface soil structure and support habitat for pollinators as 
identified in PCE 2. These two factors are sufficient to support life-
history traits of Brodiaea filifolia in the units/subunits we propose 
as critical habitat. In general, we propose units/subunits based on the 
presence of the PCEs in the appropriate quantity and spatial 
arrangement essential to the conservation of the species. In the case 
of this designation, all of the units/subunits contain both of the 
PCEs.

Special Management Considerations or Protection

    When designating critical habitat within the geographical area 
occupied by the species at the time of listing, we assess whether the 
physical and biological features essential to the conservation of the 
species may require special management considerations or protection. In 
all units/subunits, special management considerations or protection of 
the essential features may be required to provide for the growth, 
reproduction, and sustained function of the habitat on which Brodiaea 
filifolia depends.
    The lands proposed as critical habitat represent our best 
assessment of the habitat that meets the definition of critical habitat 
for Brodiaea filifolia at this time. The essential physical or 
biological features within the areas proposed as critical habitat may 
require some level of management to address current and future threats 
to B. filifolia, including the direct and indirect effects of habitat 
loss and degradation from urban development; the introduction of 
nonnative invasive plant species; recreational activities; discing and 
mowing for agricultural practices or fuel modification for fire 
management; and dumping of manure and sewage sludge.
    Loss and degradation of habitat from development was cited in the 
final listing rule as a primary cause for the decline of Brodiaea 
filifolia. Most of the populations of this species are located in San 
Diego, Orange, and Riverside Counties. These counties have had (and 
continue to have) increasing human populations and attendant housing 
pressure. Natural areas in these counties are frequently near or 
bounded by urbanized areas. Urban development removes the plant 
community components and associated clay soils identified in the PCEs, 
which eliminates or fragments the populations of B. filifolia. Grading, 
discing, and scraping areas in the preparation of areas for 
urbanization also directly alters the soil surface as well as 
subsurface soil layers to the degree that they will no longer support 
plant community types and pollinators associated with B. filifolia (PCE 
2).
    Nonnative invasive plant species may alter the vegetation 
composition or physical structure identified in the PCEs to an extent 
that the area does not support Brodiaea filifolia or the plant 
community that it inhabits. Additionally, invasive species may compete 
with B. filifolia for space and resources by depleting water that would 
otherwise be available to B. filifolia.
    Unauthorized recreational activities may impact the vegetation 
composition and soil structure that supports Brodiaea filifolia to an 
extent that the area will no longer have intact soil surfaces or the 
plant communities identified in the PCEs. Off-highway vehicle (OHV) 
activity is an example of this type of activity.
    Some methods of mowing or discing for agricultural purposes or fuel 
modification for fire management may preclude the full and natural 
development of Brodiaea filifolia by adversely affecting the PCEs. 
Mowing may preclude the successful reproduction of the plant, or alter 
the associated vegetation needed for pollinator activity (PCE 2). 
Dumping of sewage sludge can cover plants as well as the soils they 
need. Additionally, this practice can alter the chemistry of the 
substrate and lead to alterations in the vegetation supported at the 
site (PCE 1).
    In summary, we find that the areas we are proposing as revised 
critical habitat contain the features essential to the

[[Page 64938]]

conservation of Brodiaea filifolia, and that these features may require 
special management considerations or protection. Special management 
considerations or protection may be required to eliminate, or reduce to 
negligible level, the threats affecting each unit/subunit and to 
preserve and maintain the essential features that the proposed critical 
habitat units/subunits provide to B. filifolia. Additional discussions 
of threats facing individual sites are provided in the individual unit/
subunit descriptions.
    The designation of critical habitat does not imply that lands 
outside of critical habitat may not play an important role in the 
conservation of Brodiaea filifolia. In the future, and with changed 
circumstances, these lands may become essential to the conservation of 
B. filifolia. Activities with a Federal nexus that may affect areas 
outside of critical habitat, such as development, agricultural 
activities, and road construction, are still subject to review under 
section 7 of the Act if they may affect B. filifolia because Federal 
agencies must consider both effects to the plant and effects to 
critical habitat independently. The prohibitions of section 9 of the 
Act applicable to B. filifolia under 50 CFR 17.71 (e.g., the 
prohibition against reducing to possession or maliciously damaging or 
destroying listed plants on Federal lands) also continue to apply both 
inside and outside of designated critical habitat.

Criteria Used To Identify Critical Habitat

    We have determined that all areas we are proposing to designate as 
revised critical habitat are within the geographical area occupied by 
Brodiaea filifolia at the time of listing (see the ``Spatial 
Distribution and Historical Range'' section for more information), and 
are currently occupied. We considered the areas outside the 
geographical area occupied by the species at the time of listing, but 
are not proposing to designate any areas outside the geographical area 
occupied by B. filifolia at the time of listing because we determined 
that a subset of occupied lands within the species' historical range 
are adequate to ensure the conservation of B. filifolia. Occupied areas 
exist throughout this species' historical range, and through the 
conservation of a subset of occupied habitats (35 of 68 extant 
occurrences, see Table 1), we will be able to stabilize and conserve B. 
filifolia throughout its current and historical range. All units/
subunits proposed as critical habitat contain both PCEs in the 
appropriate quantity and spatial arrangement essential to the 
conservation of this species and support multiple life-history traits 
for B. filifolia.
    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 Brodiaea 
filifolia. The ``Methods'' section summarizes the data used for this 
proposed revised critical habitat. This proposed rule reflects the best 
available scientific and commercial information and thus differs from 
our 2005 final critical habitat rule.
    This section provides details of the process we used to delineate 
critical habitat. This proposed rule reflects a progression of 
conservation efforts for Brodiaea filifolia. This progression is based 
largely on the past analysis of the areas identified as meeting the 
definition of critical habitat for B. filifolia as identified in the 
2004 proposed critical habitat rule and the 2005 final critical habitat 
designation, and new information we obtained on the species' 
distribution since listing. In some areas that were ana