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

Federal RegisterDec 8, 2009

Ask Donna

What actually matters in this document.

Text

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.

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:

http://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

http://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

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

http://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

http://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

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

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

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

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

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

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

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

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 analyzed in 2005, we have new distribution information that resulted in adding areas to the 2005 critical habitat designation. There are also some areas identified as meeting the definition of critical habitat in the 2005 critical habitat that we did not include in this revision of critical habitat because we determined based on a review of the best available information that they do not meet the definition of critical habitat. The specific differences from the 2005 designation of critical habitat are summarized in the

Summary of Changes From Previously Designated Critical Habitat

section of this rule.

Species and plant communities that are protected across their ranges are expected to have lower likelihoods of extinction (Soule and Simberloff 1986, p. 35; Scott

et al

. 2001, pp. 1297-1300). Genetic variation generally results from the effects of population isolation and adaptation to locally distinct environments (Lesica and Allendorf 1995, pp. 754-757; Fraser 2000, pp. 49-51; Hamrick and Godt 1996, pp. 291-295). We sought to include the range of ecological conditions in which

Brodiaea filifolia

is found to preserve the genetic variation that may reflect adaptation to local environmental conditions, as documented in other plant species (such as in Hamrick and Godt 1996, pp. 299-301; or Millar and Libby 1991, pp. 150, 152-155). A suite of locations that possess unique ecological characteristics will represent more of the environmental variability under which

B. filifolia

has evolved. Protecting these areas will promote the adaptation of the species to different environmental conditions and contribute to species recovery.

We also determined that habitat for pollinators is essential to the survival and recovery of this species because

Brodiaea filifolia

is self-incompatible (genetically similar individuals are not able to produce viable seeds). Sexual reproduction, facilitated through pollination, is necessary for the long-term conservation of this species.

All critical habitat discussed in this proposed revision of critical habitat is occupied by the species at the subunit level meaning that each subunit contains at least one known occurrence of

Brodiaea filifolia

. The essential features in each subunit are necessary for the conservation of the occurrence within the subunit, and the subunit contributes to the overall conservation of the species. Occupied areas were determined from survey data and element occurrence data in the CNDDB (CNDDB 2009, pp. 1-76). Using GIS data in the areas identified as occupied by this species as a guide, we identified the areas that contain the physical and biological features essential to the conservation of

B. filifolia

To map the areas that meet the definition of critical habitat, we identified areas that contain the PCEs in the quantity and spatial distribution essential to the conservation of this species using the following criteria: (1) Areas supporting occurrences on rare or unique habitat within the species' range; (2) areas supporting the largest known occurrences of

B. filifolia

; or (3) areas supporting stable occurrences of

B. filifolia

that are likely to be persistent. These criteria are explained in greater detail below and a summary of our analysis of all current and past areas supporting

Brodiaea filifolia

is presented in Table 1.

We have determined that 35 of the 68 extant occurrences meet the definition of critical habitat; of these 35 occurrences, 7 occur on MCB Camp Pendleton and are exempt from critical habitat under section 4(a)(3) of the Act, and 28 occurrences are proposed as critical habitat. Areas containing the PCEs and that meet at least one of the above criteria are considered to contain the physical and biological features essential to the conservation of the species and, therefore, meet the definition of critical habitat. Included in PCE 2 are areas up to 820 ft (250 m) from mapped occurrences of

B. filifolia

to provide adequate space to support the habitat and alternate food sources needed for pollinators of

B. filifolia

. The

820-ft (250-m) distance for determining the pollinator use area is based on a conservative estimate for the mean routine flight distance for ground-nesting solitary bees that pollinate

B. filifolia.

This distance is not meant to capture all habitat that is potentially used by pollinators, but it is meant to capture a sufficient area to allow for pollinators to nest, feed, and reproduce in habitat that is adjacent and connected to the areas were

B. filifolia

grows (see “

Habitat for Pollinators of Brodiaea filifolia

” section for a more detailed explanation of pollinator requirements and our derivation of the 820-ft (250-m) distance for determining the pollinator use area).

Table 1. Summary of criteria analysis of all recorded locations of

Brodiaea filifolia

“Occurrence number” and “Location Description” are taken from the 5-year review completed in 2009 where more information about each occurrence can be found. Extirpated occurrences were not given an “Occurrence number” in the 5-year review.

Occurrence

number in

5-year review

Location Description

CNDDB

Element

Occurrence

Number (EO)

Criterion 1:

Unique or rare habitat

Criterion 2:

Largest

occurrences

Criterion 3:

Stable and

persistent

occurrence

Critical Habitat Unit/

Subunit

Los Angeles County, California

Glendora

—

San Dimas/Gordon Highlands

—

San Bernardino County, California

Arrowhead Hot Springs

—

Waterman Canyon

—

N/A

Riverside County, California

San Jacinto Wildlife Area

—

11a

San Jacinto Ave/Dawson Rd

—

11b

Case Road

—

11c

Goetz Road

—

extirpated

Railroad Canyon

—

11d

Upper Salt Creek (Stowe Pool)

—

11e

Santa Rosa Plateau - Tenaja Rd.

—

B. santarosae

Santa Rosa Plateau - North of Tenaja Rd.

—

11h

Santa Rosa Plateau - South of Tenaja Rd.

—

11g

Santa Rosa Plateau - Mesa de Colorado

—

N/A

East of Tenaja Guard Station

—

N/A

Redonda Mesa

—

N/A

Corona Cala Camino

N/A

—

N/A

Orange County, California

Edison Viejo

—

N/A

Aliso and Woods Canyon

Wilderness Park

—

Cañada Gobernadora

/Chiquadora Ridge

—

Trampas Canyon

N/A

—

N/A

Middle Gabino

N/A

—

N/A

Cristianitos Canyon

Cristianitos Canyon/

Lower Gabino Canyon

N/A

—

East Talega/Blind Canyon

N/A

—

N/A

Casper's Wilderness Park

—

Arroyo Trabuco Golf Course/Lower Arroyo Trabuco

N/A

—

N/A

Prima Deshecha

—

extirpated

Talega/Segunda Deshecha

—

N/A

Forster Ranch

—

N/A

Cristianitos Canyon South

—

N/A

San Diego County, California

Miller Mountain

—

B. santarosae

Devil Canyon

—

Tributary off of Talega Canyon

N/A

—

N/A

Cristianitos Canyon Pendleton

N/A

—

exempt

San Mateo Creek

N/A

—

N/A

Bravo One

—

exempt

Bravo Two North

N/A

—

N/A

Bravo Two South

N/A

—

exempt

Alpha One/Bravo Three

—

N/A

Basilone/San Mateo Junction

N/A

—

exempt

Camp Horno

—

exempt

Southeast of Horno Summit

—

N/A

Top of Las Pulgas Canyon/Roblar Rd

N/A

—

N/A

Top of Aliso Canyon/Roblar Rd

N/A

—

N/A

Basilone/Roblar Junction

—

N/A

East of I-5/South of Las Flores Creek

—

N/A

Pilgrim Creek

N/A

—

exempt

Pueblitos Canyon

N/A

—

N/A

West of Whelan Lake

N/A

—

N/A

South of French Creek

N/A

—

N/A

South White Beach

N/A

—

exempt

Taylor

Undeveloped parcel between Darwin properties

Darwin Knolls and Darwin Glen

—

Arbor Creek/Colucci

N/A

—

Mission View/Sierra Ridge

—

Mesa Drive, SDG&E

Substation

—

Eternal Hills/Alta Creek Cornerstone Community Church

/Oceanside Blvd & El Camino Real

N/A

—

Vista Pacific

N/A

—

N/A

Buena Vista Creek preserve

N/A

—

N/A

Calavera Heights Mitigation Site

N/A

—

N/A

Calavera Hills Village H

—

Calavera Hills Village X

—

N/A

Letterbox Canyon - Taylor Made

N/A

Letterbox Canyon - Salk/Fox-Miller

N/A

—

Letterbox Canyon - Newton Business Center

North of Carlsbad dragstrip

—

extirpated

Carlsbad Oaks

N/A

—

N/A

Rancho Carrillo

—

Rancho Santa Fe Rd North

—

N/A

Rancho La Costa

—

La Costa Town Square

N/A

—

N/A

Park View West/La Costa Ave & Rancho Santa Fe Rd

—

extirpated

Poinsettia

N/A

—

N/A

Shelley Property/Olivenhein & Rancho Santa Fe Rd junction

—

extirpated

Calle Tres Vistas

—

extirpated

Vista

—

extirpated

Brengle Terrace

—

extirpated

Vista, east of South Melrose Ave

—

extirpated

North of Carlsbad dragstrip

—

extirpated

SSE of Buena, near Mission Rd & RR tracks

—

extirpated

Rancho Santalina

Loma Alta

—

New Millennium

Las Posas Road Extension Project

—

extirpated

Grand Avenue/Las Posas Rd pools

—

Upham/Pacific St/

Superior Ready Mix

Oleander/San Marcos Elementary

N/A

—

Artesian Trails

—

4S Ranch

N/A

—

extirpated

California Department of Fish and Game, Natural Diversity Database

New occurrence since listing, but determined to be occupied at the time of listing

Partially translocated (some plants currently exist at the original location)

Completely translocated (no plants currently exist at the original location)

We identified habitat containing the features essential to the conservation of

Brodiaea filifolia

by using data from the following GIS databases: (1) Species occurrence information in Los Angeles, San Bernardino, Orange, Riverside, and San Diego Counties from the CNDDB and from survey reports; (2) vegetation data layers from Orange, Riverside, and San Diego Counties and vegetation data layers from the U.S. Forest Service's Cleveland National Forest for Los Angeles and San Bernardino Counties; and (3) Natural Resources Conservation Service's Soil Survey Geographic Database (SSURGO) soil data layers for Orange, Riverside, and San Diego Counties, and State Soil Geographic Database (STATSGO) soil data layers for Los Angeles and San Bernardino Counties.

Criteria Used

If occurrences and habitat areas met one or more of the following criteria, they are proposed as critical habitat in this revised critical habitat designation.

(1) The first criterion is any area that supports an occurrence in rare or unique habitat within the species' range. We evaluated all occurrences of

Brodiaea filifolia

under this criterion, regardless of occurrence size. We identified four main factors that constitute rare or unique habitat for

B. filifolia

(a) Occurrences in habitat types that are uncommon such as grassland habitat that occurs intermixed with chaparral, grassland habitat that is associated with vernal pools, or large areas of native grassland;

(b) occurrences on uncommon soil types such as clay soils that are altered by hydrothermal activity;

(d) occurrences that grow in gravel, cobbles, and small boulder substrate.

These four unique situations differ from the majority of occurrences of this species, which are found on clay soils intermixed with coastal sage scrub habitat. The conservation of

Brodiaea filifolia

occurring in these rare or unique situations will preserve the diversity of habitats where this species is found.

(2) The second criterion is any area that supports one of the largest known populations of

Brodiaea filifolia

. Occurrences of this species range from just a few plants to several thousand plants, while the majority of the known occurrences are under 3,000 plants (see the

Background

section for a discussion on how occurrences of

B. filifolia

are grouped and counted). However, there are 13 occurrences that stand out as the largest, each having greater than 3,000 plants. Occurrences supporting large numbers of plants (3,000 or more) are noted in Table 1 and are found in the following areas:

(a) Los Angeles County, Subunit 1b-San Dimas;

(b) Riverside County, Subunit 11a-San Jacinto Wildlife Area, Subunit 11c-Case Road, Subunit 11d-Railroad Canyon, Subunit, and 11f-Santa Rosa Plateau — Mesa de Colorado;

(d) San Diego County, Subunit 6d-Taylor/Darwin, Subunit 7a-Letterbox Canyon, Subunit 7b-Rancho Carrillo, Subunit 7d-Rancho La Costa, Subunit 8d-Upham, and Subunit 8f-Oleander/San Marcos Elementary (See Table 1).

These large occurrences are present in habitat areas that contain the features essential to the conservation of this species. These areas generally represent large contiguous blocks of intact habitat. The conservation of these large populations will increase the resilience of the species across its range and contribute to the overall recovery of this species.

(3) The third criterion is any area that supports an occurrence considered to be stable and persistent. We consider occurrences that have between 850 and 3,000 flowering stems that have been observed in multiple years to be stable and persistent because we expect these occurrences to have a sufficient amount of corms to sustain the occurrence for a number of years if the habitat remains unaltered. These areas contribute to the conservation of

Brodiaea filifolia

because they provide resilience for the species by minimizing the effects on the species from the loss of any single occurrence, and the conservation of these areas helps to maintain the diversity of habitat where this species occurs. The conservation of these areas allows

B. filifolia

to maintain its current geographic distribution. The conservation of stable and persistent occurrences throughout the species' range helps to maintain connectivity between occurrences that are in proximity to one another and maintain potential gene flow. This is particularly important for

B. filifolia

because this species relies on outcrossing for successful reproduction.

To determine which areas met this criterion, we identified occurrences with counts of between 850 and 3,000 flowering stalks that had been observed in multiple years. Additionally, we looked at all occurrences with fewer than 850 flowering stalks to determine if any of these exhibited the same persistence and stability characteristics to provide similar conservation value as the other identified occurrences with greater than 850 flowering stalks (since the counts for an occurrence vary from year to year). We found that one occurrence with fewer than 850 flowering stalks (at the Arbor Creek/Colucci site) exhibited characteristics of a stable, persistent occurrence (i.e., consistent size not substantially different than 850 flowering stalks); therefore, this occurrence fulfills the ecological role of sites we are interested in identifying through this criterion, even though the high count at this site is 620 flowering stalks.

Of the 68 occurrences of

Brodiaea filifolia

that we identified as being extant in our 5-year review for this species, 35 occurrences meet one or more of the three criteria outlined above. Seven of these 35 occurrences are exempt from critical habitat under section 4(a)(3) of the Act (see “

Exemptions Under Section 4(a)(3) of the Act

”), the remaining 28 occurrences are proposed as revised critical habitat. Thirteen occurrences, of the 28 proposed occurrences, fit into one of the four reasons that areas meet the “rare or unique habitat” criterion; 13 occurrences meet the “largest occurrences” criterion; and 11 occurrences meet the “stable and persistent occurrences” criterion. These occurrences represent the historical range of the species and are adequate to provide for this species' conservation. Occurrences not identified in this process may still be important to the conservation of this species, but without the conservation of the occurrences identified through this process, the recovery effort for this species may be impaired.

Other Factors Involved With Delineating Critical Habitat

Following the identification of 35 occurrences of the 68 extant occurrences that met one of the 3 criteria listed above, we mapped the area that contained the PCEs at each occurrence including the areas out up to 820 ft (250 m) of mapped occurrences of

Brodiaea filifolia

to provide adequate space to support the habitat and alternate food sources needed for pollinators of

B. filifolia

(see “

Habitat for Pollinators of Brodiaea filifolia

” section).

Areas that did not provide habitat for

Brodiaea filifolia

or potential pollinators were removed from the 820-ft (250-m) zone of mapped occurrences of

B. filifolia

, such as areas that were developed or severely altered by grading. Our mapping methodology captures the PCEs in the appropriate quantity and spatial arrangement essential to the conservation of the species, and encompasses the range of environmental variability for this species. Although a genetic analysis of

B. filifolia

has not been conducted, these criteria likely capture the full breadth of important habitat types and are expected to protect the genetic variability of this species. The resulting 35 areas constitute the areas we have determined contain the physical and biological features essential to the conservation of

B. filifolia

and meet the definition of critical habitat. Seven of the 35 areas are on MCB Camp Pendleton and are exempt from this proposed revised rule under section 4(a)(3) of the Act; the other 28 areas were mapped as the proposed revised critical habitat for

B. filifolia

, and are described in this document.

When determining the proposed revised critical habitat boundaries, we made every effort to map precisely only the areas that contain the PCEs and provide for the conservation of

Brodiaea filifolia

. However, we cannot guarantee that every fraction of proposed revised critical habitat contains the PCEs due to the mapping scale that we use to draft critical habitat boundaries. Additionally, we made every attempt to avoid including developed areas such as lands underlying buildings, pavement, and other structures because such lands lack PCEs for

B. filifolia

. The scale of the maps we prepared under the parameters for publication within the Code of Federal Regulations may not reflect the exclusion of such developed lands. Any such lands inadvertently left inside critical habitat boundaries shown on the maps of this proposed revised critical habitat are excluded by text in this rule and are not proposed for critical habitat designation. Therefore, Federal actions involving these lands would not trigger section 7 consultation with respect to critical habitat and the requirement of no adverse modification, unless the specific actions may affect adjacent critical habitat.

Summary of Changes From Previously Designated Critical Habitat

The areas identified in this rule constitute a proposed revision from the areas we designated as critical habitat for

Brodiaea filifolia

on December 13, 2005 (70 FR 73820). In cases where we have new information or information that was not available for the previous designation, we made changes to the critical habitat for

B. filifolia

to ensure that this rule reflects the best scientific data available. We made changes to the PCEs and our criteria used to identify critical habitat. We incorporated information related to the taxonomy of the species including the change in plant family for

B. filifolia

. We redefined the boundaries of each subunit proposed as critical habitat to more accurately reflect the areas that include the features that are essential to the conservation of

B. filifolia,

and we analyzed new distribution data that has become available to us following the 2005 designation. The Secretary is also considering whether to exercise his

discretion to exclude specific areas from the final designation under section 4(b)(2) of the Act, including reconsidering areas excluded in the prior designation, and we are seeking public comment (see

Public Comments

section of this rule). Table 2 shows the progression of each subunit of critical habitat from the 2004 proposed critical habitat to this proposed revised critical habitat. Table 3 includes name changes that we made for some of the subunits where the old names were ambiguous or do not reflect the current name used to refer to these areas; although the names of these units changed, the locations have not changed. Following Tables 2 and 3, we provide a detailed description of each change made in this proposed revised rule and point to new information that precipitated the change.

TABLE 2. Size and evaluation of Units and Subunits for

Brodiaea filifolia

in 2004 proposed critical habitat (pCH)

2005 final critical habitat (fCH), and 2009 proposed revised critical habitat (prCH), and a comparison of the area considered to meet the definition of critical habitat between the 2005 fCH and 2009 prCH.

Unit/Subunit Number and Name

2004 pCH

2005 fCH

2009 prCH

Change from fCH to prCH

Unit 1: Los Angeles County

1a. Glendora

96 ac (39 ha)

67 ac (27 ha)

(-) 29 ac (12 ha)

1b. San Dimas

198 ac (80 ha)

138 ac (56 ha)

(-) 60 ac (24 ha)

Unit 2: San Bernardino County

2. Arrowhead Hot Springs

89 ac (36 ha)

Not designated, wrong location

61 ac (25 ha)

(+) 61 ac (25 ha)

Unit 3: Central Orange County

3. Aliso Canyon

151 ac (61ha)

Not designated, did not meet the definition of critical habitat

113 ac (46 ha)

(+) 113 ac (46 ha)

Unit 4: Southern Orange County

4a. Arroyo Trabuco

74 ac (30 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

4b. Caspers Wilderness Park

259 ac (105 ha)

259 ac (105 ha); Excluded under section 4(b)(2)

205 ac (83 ha)

(-) 54 ac (22 ha)

4c. Cañada Gobernadora/Chiquita Ridgeline

311 ac (126 ha)

311 ac (126 ha); Excluded under section 4(b)(2)

133 ac (54 ha)

(-) 178 ac (72 ha)

4d. Prima Deschecha

119 ac (48 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

4e. Forster Ranch

96 ac (39 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

4f. Talega/Segunda Deshecha

190 ac (77 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

4g. Cristianitos Canyon

588 ac (238 ha)

588 ac (238 ha); Excluded under section 4(b)(2)

587 ac (238 ha)

(-) 1ac (0.4 ha)

4h. Cristianitos Canyon South

72 ac (29 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

4i. Blind Canyon

151 ac (61 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

Unit 5: Northern San Diego County

5a. Miller Mountain

1,263 ac (511 ha)

Not designated, mostly hybrid plants

Not proposed, only

Brodiaea santarosae

present

no change

5b. Devil Canyon

264 ac (107ha)

249 ac (101 ha)

274 ac (111 ha)

(+) 25 ac (10 ha)

Unit 6: Oceanside

6a. Alta Creek

49 ac (20 ha)

Not designated, did not meet the definition of critical habitat

72 ac (29 ha)

(+) 72 ac (29 ha)

6b. Mesa Drive

5 ac (2 ha)

5 ac (2 ha); Excluded under section 4(b)(2)

17 ac (7 ha)

(+) 12 ac (5 ha)

6c. Oceanside East/Mission Avenue

64 ac (26 ha)

Not designated, did not meet the definition of critical habitat

12 ac (5 ha)

(+) 12 ac (5 ha)

6d. Taylor/Darwin

80 ac (32 ha)

36 ac (15 ha); Excluded under section 4(b)(2)

35 ac (14 ha)

(-) 45 ac (18 ha)

6e. Arbor Creek

N/A

94 ac (38 ha)

(+) 94 ac (38 ha)

Unit 7: Carlsbad

7a. Fox-Miller (Letterbox Canyon)

93 ac (38 ha)

93 ac (38 ha); Excluded under section 4(b)(2)

57 ac (23 ha)

(-) 36 ac (15 ha)

7b. Rancho Carrillo

32 ac (13 ha); Excluded under section 4(b)(2)

Not designated, did not meet the definition of critical habitat

37 ac (15 ha)

(+) 37 ac (15 ha)

7c. Calvera Hills

84 ac (34 ha); Excluded under section 4(b)(2)

71 ac (29 ha)

(-) 13 ac (5 ha)

7d. Villages of La Costa (Rancho La Costa)

208 ac (84 ha); Excluded under section 4(b)(2)

98 ac (40 ha)

(-) 110 ac (45 ha)

Carlsbad Oaks

113 ac (46 ha); Excluded under section 4(b)(2)

Not proposed, does not meet the definition of critical habitat

(-) 113 ac (46 ha)

Carlsbad Highlands

70 ac (29 ha); Excluded under section 4(b)(2)

Not proposed, does not meet the definition of critical habitat

(-) 70 ac (29 ha)

Poinsettia

54 ac (22 ha); Excluded under section 4(b)(2)

Not proposed, does not meet the definition of critical habitat

(-) 54 ac (22 ha)

Unit 8: San Marcos and Vista

8a. Rancho Santa Fe Road North

86 ac (35 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

8b. Rancho Santalina/Loma Alta

82 ac (33 ha)

Not included under section 3(5)(a)

47 ac (19 ha)

(+) 47 ac (19 ha)

8c. Grand Avenue

10 ac (4 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

8d. Upham

117 ac (47 ha)

54 ac (22 ha)

no change

8e. Linda Vista

20 ac (8 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

8f. Oleander/San Marcos Elementary

N/A

7 ac (3 ha)

(+) 7 ac (3 ha)

Unit 9

9. Double LL Ranch

57 ac (23 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

Unit 10

10. Highland Valley

74 ac (30 ha)

Not designated, did not meet the definition of critical habitat

N/A

no change

Unit 11: Western Riverside County

11a. San Jacinto Wildlife Area

512 ac (207 ha); Excluded under section 4(b)(2)

401 ac (162 ha)

(-) 110 ac (45 ha)

11b. San Jacinto Avenue/ Dawson Road

168 ac (68 ha); Excluded under section 4(b)(2)

117 ac (47 ha)

(-) 51 ac (21 ha)

11c. Case Road

373 ac (151 ha); Excluded under section 4(b)(2)

180 ac (73 ha)

(-) 193 ac (78 ha)

11d. Railroad Canyon

432 ac (175 ha); Excluded under section 4(b)(2)

257 ac (104 ha)

(-) 175 ac (71 ha)

11e. Upper Salt Creek (Stowe Pool)

131 ac (53 ha); Excluded under section 4(b)(2)

145 ac (59 ha)

(+) 14 ac (6 ha)

11f. Santa Rosa Plateau — Mesa de Colorado

519 ac (210 ha); Excluded under section 4(b)(2)

234 ac (95 ha)

(-) 285 ac (115 ha)

Santa Rosa Plateau — Tenaja Rd.

304 ac (123 ha); Excluded under section 4(b)(2)

Not proposed; only

Brodiaea santarosae

present

(-) 304 ac (123 ha)

11g. Santa Rosa Plateau — South of Tenaja Rd.

218 ac (88 ha); Excluded under section 4(b)(2)

117 ac (47 ha)

(-) 101 ac (41 ha)

11h. Santa Rosa Plateau — North of Tenaja Rd.

111 ac (45 ha); Excluded under section 4(b)(2)

44 ac (18 ha)

(-) 67 ac (27 ha)

East of Tenaja Guard Station

218 ac (88 ha); Excluded under section 4(b)(2)

Not proposed, does not meet the definition of critical habitat

(-) 218 ac (88 ha)

N. End Redondo Mesa

77 ac (31 ha); Excluded under section 4(b)(2)

Not proposed, does not meet the definition of critical habitat

(-) 77 ac (31 ha)

Corona (north)

74 ac (30 ha); Excluded under section 4(b)(2)

Not designated, did not meet the definition of critical habitat

N/A

no change

Corona (south)

67 ac (27 ha); Excluded under section 4(b)(2)

Not designated, did not meet the definition of critical habitat

N/A

no change

Moreno Valley

64 ac (26 ha); Excluded under section 4(b)(2)

Not designated, did not meet the definition of critical habitat

N/A

no change

Unit 12: Central San Diego County - Artesian Trails

12. Artesian Trails

N/A

109 ac (44 ha)

(+) 109 ac (44 ha)

TOTAL FOR

NON-MILITARY LANDS

8,486 ac (3,434 ha)

5,480 ac (2,218 ha)

3,786 ac (1,532 ha)

(-) 1,695 ac (686 ha)

MCB Camp Pendleton

Cristianitos Canyon Pendleton

N/A

190 ac (77 ha); 4(a)(3) exemption

(+) 190 ac (77 ha)

Bravo One

121 ac (41 ha); Excluded under section 4(b)(2)

121 ac (41 ha); 4(a)(3) exemption

143 ac (58 ha); 4(a)(3) exemption

(+) 22 ac (9 ha)

Bravo Two South

N/A

269 ac (109 ha); 4(a)(3) exemption

(+) 269 ac (109 ha)

Alpha One/Bravo Three

114 ac (46 ha); Excluded under section 4(b)(2)

114 ac (46 ha); 4(a)(3) exemption

Does not meet the definition of critical habitat

(-) 114 ac (46 ha)

Basilone/San Mateo Junction

N/A

163 ac (66 ha); 4(a)(3) exemption

(+) 163 ac (66 ha)

Camp Horno

452 ac (183 ha); Excluded under section 4(b)(2)

452 ac (183 ha); 4(a)(3) exemption

339 ac (137 ha); 4(a)(3) exemption

(-) 113 ac (46 ha)

SE Horno Summit

116 ac (47 ha); Excluded under section 4(b)(2)

116 ac (47 ha); 4(a)(3) exemption

Does not meet the definition of critical habitat

(-) 116 ac (47 ha)

Kilo One

114 ac (46 ha); Excluded under section 4(b)(2)

114 ac (46 ha); 4(a)(3) exemption

Does not meet the definition of critical habitat

(-) 114 ac (46 ha)

Pilgrim Creek

N/A

368 ac (149 ha); 4(a)(3) exemption

(+) 368 ac (149 ha)

South White Beach

N/A

59 ac (24 ha); 4(a)(3) exemption

(+) 59 ac (24 ha)

TOTAL FOR MILITARY LANDS

917 ac (371 ha)

917 ac (371 ha); 4(a)(3) exemption

1,531 ac (620 ha)

(+) 614 ac (249 ha)

TOTAL AREA THAT MEETS (or MET) THE DEFINITION OF CRITICAL HABITAT

9,403 ac (3,805 ha)

6,397 ac (2,589 ha)

5,317 ac (2,152 ha)

(-) 1,080 ac (438 ha)

This table does not include all locations that are occupied by

Brodiaea filifolia

. It includes only those locations that have met the definition of critical habitat in this or one of the past proposed or final critical habitat rules for

B. filifolia

Values in this table may not sum due to rounding.

Military Lands are exempt from this rule under section 4(a)(3) of the Act.

TABLE 3. Name changes from previous critical habitat to this proposed revised critical habitat.

Subunit number

Previous name

Current name

Reason for change

Oceanside East/Mission Ave

Mission View/Sierra Ridge

Not the eastern most occurrence in Oceanside

Fox-Miller

Letterbox Canyon

Includes more properties that just Fox-Miller

Calavera Heights

Calavera Hills Village H

New name is more specific

11b

San Jacinto Floodplain

San Jacinto Avenue/Dawson Road

New name is more specific

11c

Case Road Area

Case Road

New name is more specific

(1) We refined the PCEs to more accurately define the physical and biological features that are essential to the conservation of

Brodiaea filifolia

. We added a new part under PCE 1 (PCE 1B) to more clearly define the soils where

B. filifolia

occurs in San Bernardino County. We added information to PCE 2 to indicate that land out up to 820 ft (250 m) from mapped occurrences contains the physical and biological features essential to the conservation of

B. filifolia

because that area provides habitat for insect species that pollinate

B. filifolia

and allow this species to sexually reproduce. This information was discussed in the 2005 final critical habitat; however, it was not specifically included in the PCEs.

(2) We revised the criteria used to identify critical habitat. We started by using the basic criteria used in the 2005 final critical habitat designation. However, in this proposed revised critical habitat we gathered new data available since the publication of the 2005 rule and reevaluated all of the

Brodiaea filifolia

data available to ensure that this proposed rule reflected the best available science. With the additional data and our reevaluation of the available data, some of our conclusions were different than those we made in the 2005 critical habitat designation. As a result, some areas identified as meeting the definition of critical habitat in the 2005 designation are not included in this proposed rule (such as areas on Santa Rosa Plateau that support

B. santarosae

instead of

B. filifolia

and areas in the City of Carlsbad that contain smaller occurrences of

B. filifolia

that did not meet any of our three criteria), and other areas were included in this proposed rule that were not identified as meeting the definition of critical habitat in the 2005 designation (such as areas in existence at the time of listing, but not evaluated or included due to lack of surveys for

B. filifolia

). We described the steps that we used to identify and delineate the areas that we are proposing as critical habitat in more detail compared to the 2005 critical habitat designation to ensure that the public better understands why the areas are being proposed as critical habitat.

(3) We improved our mapping methodology to more accurately define those areas that possess the physical and biological features essential to the conservation of the species and to more precisely draw critical habitat boundaries. This proposed revised rule identifies 1,695 (686 ha) considered to contain the features essential to the conservation of

Brodiaea filifolia

less than we identified in the 2005 rule (this calculation does not include the changes made on military lands exempt under section 4(a)(3) of the Act, see Table 2). This reduction is primarily due to our attempt to better represent the areas that contain the physical and biological features essential to the conservation of

B. filifolia

. In the 2005 final rule, we used a 100-meter grid resolution to delineate critical habitat. In this proposed revised rule, we did not use the 100-meter grid mapping methodology. Instead we directly mapped the areas containing the PCEs. We believe the result is a more precise mapping of the proposed critical habitat. However, we acknowledge that there still may be some areas mapped as critical habitat that do not contain the PCEs due to mapping, data, and resource constraints.

(4) In the 2005 rule, we excluded subunits under section 4(b)(2) of the Act within the planning boundaries for: (a) The Orange County Southern Subregion HCP, (b) the draft City of Oceanside Subarea Plan and the City of Carlsbad's HMP under the MHCP, (c) the Villages of La Costa HCP, and (d) the Western Riverside County MSHCP (see Table 2 for the specific subunits excluded). In this proposed revised critical habitat rule, we identified several areas we are considering for exclusion under section 4(b)(2) of the Act, as follows: (a) The Orange County Southern Subregion HCP, (b) the City of Carlsbad's HMP under the MHCP (which includes the Villages of La Costa Habitat Conservation Plan), (c) the Western Riverside County MSHCP, and (d) the City and County of San Diego Subarea Plans under the MSCP (see the

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section). The Villages of La Costa HCP is included within (considered part of) the City of Carlsbad's HMP under the MHCP; therefore, all proposed critical habitat that overlaps with the Villages of La Costa HCP is being considered for exclusion under the City of Carlsbad's HMP. We are currently not considering the exclusion of critical habitat within the area covered by the draft City of Oceanside Subarea Plan (which was excluded previously). The exclusions in the final revised critical habitat designation could differ from the exclusions we made in the 2005 final critical habitat designation.

(5) New information resulted in additional areas being identified as meeting the definition of critical habitat for

Brodiaea filifolia

. First, we added two areas that are newly discovered to support occurrences of

B. filifolia

; however, we believe that these areas were occupied at the time of listing (Subunit 8f and Unit 12). Second, we have new information on four areas containing substantial occurrences that were proposed as critical habitat in 2004 but not designated in the 2005 final rule because at that time the data did not indicate these areas were substantial occurrences (Unit 3 and Subunits 6a, 6c, and 7b). We now have information, mostly in the form of updated surveys, indicating that these areas contain substantial occurrences of

B. filifolia

and meet the definition of critical habitat (see Criteria 2 above under the “

Criteria Used To Identify Critical Habitat

” section). Third, we added two areas where the previously identified subunits were placed in the wrong locations and did not contain the actual occurrences of

B. filifolia

that they were intended to contain (Unit 2 and Subunit 11e); we have now identified and mapped the correct areas. Fourth, we added land to seven proposed subunits where new survey data indicated these lands contain the physical and biological features essential to the conservation of

B. filifolia

(Subunits 4g, 5b, 6a, 6b, 7a, 11a, and 11f).

(6) New information also resulted in the removal of areas previously identified as meeting the definition of critical habitat for

Brodiaea filifolia

. First, ten areas identified as meeting the definition of critical habitat in the 2004 proposed rule are not proposed in this revision of critical habitat. The best available scientific and commercial data indicates that these occurrences do not meet the criteria in this proposed rule to identify areas containing the essential physical and biological features (Carlsbad Oaks, Carlsbad Highlands, Poinsettia, East of Tenaja Guard Station, North end of Redondo Mesa, three areas on Marine Corps Base Camp Pendleton, Unit 9/Double LL Ranch, and Unit 10/Highland Valley). Second, we are not proposing two areas where the new species of

Brodiaea, B. santarosae,

was found and no

B. filifolia

was found (Santa Rosa Plateau — Tenaja Rd. and Subunit 5a/Miller Mountain). These areas were thought to contain both pure

B. filifolia

and hybrid

B. filifolia

in the past; however, current data indicates that these areas only contain

B. santarosae

. Third, in 14 proposed subunits we are not proposing specific areas that previously (in the 2005 rule) met the definition of critical habitat because these specific areas do not contain the physical and biological features essential to the conservation of

B. filifolia

(portions of Subunits 1a, 1b, 4b, 4c, 4g, 6c, 6d, 7c, 7d, 11a, 11b, 11c, 11d, and 11f). More information about

the units and subunits that contain the physical and biological features essential to the conservation of

B. filifolia

and are proposed as revised critical habitat are described in greater detail in the

Proposed Revised Critical Habitat Designation

section.

Proposed Revised Critical Habitat Designation

We are proposing 3,786 ac (1,532 ha) in 10 units, subdivided into 28 subunits as revised critical habitat for

Brodiaea filifolia

. The unit numbers in this proposed rule correspond to those used in the 2004 proposed rule and the 2005 final rule; however, Units 9 and 10 are not proposed and Units 11 and 12 are new to this proposed rule. Unit 11 represents lands in Riverside County excluded from the 2005 designation of critical habitat and Unit 12 represents the Artesian Trails area in San Diego County that is now included based on new data on occurrences in this area. To minimize confusion with the previous proposal and designation we are not using Unit numbers 9 and 10 in this rule (see Table 2 and

Summary of Changes From Previously Designated Critical Habitat

section).

The areas we describe below constitute our best assessment at this time of areas that meet the definition of critical habitat for

Brodiaea filifolia

. These areas constitute our best assessment of areas determined to be within the geographical area occupied at the time of listing that contain the physical and biological features essential to the conservation of

B. filifolia

that may require special management considerations or protection. We are not proposing any areas outside the geographical area occupied by the species at the time of listing because we determined that the lands we are proposing as critical habitat are adequate to ensure conservation of

B. filifolia

. The lands proposed as revised critical habitat represent a subset of the total lands occupied by

B. filifolia

. Table 4 identifies the approximate area of each proposed critical habitat subunit by land ownership. These subunits, which generally correspond to the geographic area of the subunits delineated in the 2005 designation (see Table 2 for a detailed comparison of this proposed rule and the 2005 designation), if finalized, will replace the current critical habitat designation for

B. filifolia

in 50 CFR 17.96(a).

TABLE 4. Area estimates in acres (ac) and hectares (ha), and land ownership for

Brodiaea filifolia

proposed revised critical habitat.

Location

Ownership

Federal

State Government

Local Government

Private

Total Area

Unit 1: Los Angeles County

1a. Glendora

0 ac (0 ha)

67 ac (27 ha)

1b. San Dimas

13 ac (5 ha)

0 ac (0 ha)

125 ac (51 ha)

138 ac (56 ha)

Unit 2: San Bernardino County

2. Arrowhead Hot Springs

0 ac (0 ha)

61 ac (25 ha)

Unit 3: Central Orange County

3. Aliso Canyon

0 ac (0 ha)

113 ac (46 ha)

0 ac (0 ha)

113 ac (46 ha)

Unit 4: Southern Orange County

4b. Caspers Wilderness Park

0 ac (0 ha)

185 ac (75 ha)

20 ac (8 ha)

205 ac (83 ha)

4c. Cañada Gobernadora/Chiquita Ridgeline

0 ac (0 ha)

133 ac (54 ha)

4g. Cristianitos Canyon

0 ac (0 ha)

587 ac (238 ha)

Unit 5: Northern San Diego County

5b. Devil Canyon

266 ac (108 ha)

0 ac (0 ha)

8 ac (3 ha)

274 ac (111ha)

Unit 6: Oceanside

6a. Alta Creek

0 ac (0 ha)

72 ac (29 ha)

6b. Mesa Drive

0 ac (0 ha)

17 ac (7 ha)

6c. Mission View/Sierra Ridge

0 ac (0 ha)

12 ac (5 ha)

6d. Taylor/Darwin

0 ac (0 ha)

35 ac (14 ha)

6e. Arbor Creek

0 ac (0 ha)

94 ac (38 ha)

Unit 7: Carlsbad

7a. Letterbox Canyon

0 ac (0 ha)

57 ac (23 ha)

7b. Rancho Carrillo

0 ac (0 ha)

37 ac (15 ha)

7c. Calavera Hills Village H

0 ac (0 ha)

71 ac (29 ha)

7d. Rancho La Costa

0 ac (0 ha)

98 ac (40 ha)

Unit 8: San Marcos and Vista

8b. Rancho Santalina/Loma Alta

0 ac (0 ha)

47 ac (19 ha)

8d. Upham

0 ac (0 ha)

54 ac (22 ha)

8f. Oleander/San Marcos

0 ac (0 ha)

7 ac (3 ha)

Unit 9: Double LL Ranch - No longer proposed

Unit 10: Highland Valley - No longer proposed

Unit 11: Western Riverside County

11a. San Jacinto Wildlife Area

0 ac (0 ha)

385 ac (156 ha)

0 ac (0 ha)

16 ac (6 ha)

401 ac (162 ha)

11b. San Jacinto Avenue/ Dawson Road

0 ac (0 ha)

117 ac (47 ha)

11c. Case Road

0 ac (0 ha)

180 ac (73 ha)

11d. Railroad Canyon

53 ac (21 ha)

0 ac (0 ha)

205 ac (83 ha)

257 ac (104 ha)

11e. Upper Salt Creek (Stowe Pool)

0 ac (0 ha)

145 ac (59 ha)

11f. Santa Rosa Plateau - Mesa de Colorado

0 ac (0 ha)

221 ac (89 ha)

5 ac (2 ha)

8 ac (3 ha)

234 ac (95 ha)

11g. Santa Rosa Plateau - South of Tenaja Road

0 ac (0 ha)

117 ac (47 ha)

0 ac (0 ha)

117 ac (47 ha)

11h. Santa Rosa Plateau - North of Tenaja Road

0 ac (0 ha)

44 ac (18 ha)

0 ac (0 ha)

44 ac (18 ha)

Unit 12: Central San Diego County - Artesian Trails

12. Artesian Trails

0 ac (0 ha)

109 ac (44 ha)

Total

332 ac (134 ha)

766 ac (310 ha)

303 ac (123 ha)

2,385 ac (965 ha)

3,786 ac (1,532 ha)

1,531 ac (620 ha) of federally owned land on MCB Camp Pendleton is exempt from this critical habitat (see

Exemptions Under Section 4(a)(3) of the Act

section).

Values in this table may not sum due to rounding.

Presented below are brief descriptions of all subunits and reasons why they meet the definition of critical habitat for

Brodiaea filifolia

. The subunits are listed in order geographically north to south and west to east.

Unit 1: Los Angeles County

Unit 1 is located in Los Angeles County and consists of two subunits totaling 206 ac (83 ha). This unit contains 13 ac (5 ha) of federally owned land and 192 ac (78 ha) of private land.

Subunit 1a: Glendora

Subunit 1a consists of 67 ac (27 ha) of private land in the City of Glendora,

in the foothills of the San Gabriel Mountains in Los Angeles County. Lands within this subunit contain Cieneba-Exchequer-Sobrante soils, a type of silty loam, and consist primarily of northern mixed chaparral and coastal sage scrub habitat. Subunit 1a contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including sandy loam soils (PCE 1E) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); (2) supports a rare or unique occurrence, representing one of two occurrences located in the foothills of the San Gabriel Mountains part of the Transverse Ranges where the species was historically found; and (3) supports a stable, persistent occurrence. The site is owned and managed by the Glendora Community Conservancy (GCC). The GCC has expressed interest in creating a management plan for their land; however, the plan has not been completed at this time. The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Subunit 1b: San Dimas

Subunit 1b consists of 13 ac (5 ha) Federal land (Angeles National Forest) and 125 ac (51 ha) of private land near the City of San Dimas in the foothills of the San Gabriel Mountains in Los Angeles County. Lands within this subunit contain Cieneba-Exchequer-Sobrante soils, a type of silty loam, and consist primarily of northern mixed chaparral and coastal sage scrub habitat. Subunit 1b contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including sandy loam soils (PCE 1E) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

, as documented in 1990 (CNDDB 2009, p. 37). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from urban development on private lands, including minimizing disturbance to the surface and subsurface structure. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Unit 2: San Bernardino County -

Arrowhead Hot Springs

Unit 2 is located in San Bernardino County and consists of 61 ac (25 ha) of private land at the southwestern base of the San Bernardino Mountains. This unit was not included in the 2005 final critical habitat designation but is included in this proposed rule based on new information related to the distribution of

Brodiaea filifolia

. Lands within this unit contain Cieneba-rock outcrop complex and Ramona family-Typic Xerothents soils altered by hydrothermal activity, some of which are considered alluvial, and consist primarily of coastal sage scrub habitat. Unit 2 contains the physical and biological features essential to the conservation of

B. filifolia

because it (1) contains the PCEs for

B. filifolia

, including soils altered by hydrothermal activity (PCE 1B) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); (2) supports a rare or unique occurrence, representing the only occurrence of this plant in the foothills of the San Bernardino Mountains part of the Transverse Ranges where the species was historically found, and representing the type locality for

B. filifolia

(Niehaus 1971, p. 57; CNDDB 2009, p. 7); and (3) supports a stable, persistent occurrence. The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Unit 3: Central Orange County

- Aliso Canyon

Unit 3 is located in central Orange County and consists of 113 ac (46 ha) of local government land in Aliso and Wood Canyons Wilderness Park, in the City of Laguna Niguel, southwestern Orange County. This unit was not included in the 2005 final critical habitat designation but is included in this proposed rule based on new information related to the distribution of

Brodiaea filifolia

. Lands within this unit contain clay loam or other types of loam and consist of annual and needlegrass grassland. Unit 3 contains the physical and biological features essential to the conservation of

B. filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports an occurrence of at least 5,000 individuals of

B. filifolia

, as documented in 2001 (CNDDB 2009, p. 51). Although this occurrence is protected from urban development as part of Aliso and Wood Canyons Wilderness Park, these lands are managed for recreational use and not specifically for the conservation of

B. filifolia

. The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from fuel management activities (annual mowing) and pipeline work. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Unit 4: Southern Orange County

Unit 4 is located in southern Orange County and consists of three subunits totaling 925 ac (374 ha). This unit contains 185 ac (75 ha) of local government land and 740 ac (299 ha) of private land.

Subunit 4b: Caspers Wilderness Park

Subunit 4b consists of 185 ac (75 ha) of local government land in Caspers Wilderness Park and 20 ac (8 ha) of private land in the City of San Juan Capistrano, in the southwestern region of the Santa Ana Mountains, southern Orange County. Lands within this proposed subunit contain clay loam, sandy loam, or rocky outcrop, and consist primarily of grassland and sagebrush-buckwheat scrub habitat. Subunit 4b contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including clay soils and loamy soils underlain by a clay subsoil (PCE 1A), and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports a stable, persistent occurrence.

This subunit is located in the foothills of the Santa Ana Mountains and represents the highest elevation and northernmost occurrence in Orange County. Ninety percent of this occurrence is protected from urban development as part of Caspers Wilderness Park; these lands will be managed and monitored in accordance with the Orange County Southern Subregion HCP for conservation of

B. filifolia

. The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations. We are considering the portion of this subunit owned by Orange County at Caspers Wilderness Park (185 ac (75 ha)) for exclusion under section 4(b)(2) of the Act because this subunit is within the area addressed by the Orange County Southern Subregion HCP; please see the

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 4c: Cañada Gobernadora/Chiquita Ridgeline

Subunit 4c consists of 133 ac (54 ha) of private land in and around Cañada Gobernadora on Rancho Mission Viejo in southern Orange County. Lands within this subunit contain clay, clay loam, or sandy loam and consist primarily of dry-land agriculture and sagebrush-buckwheat scrub habitat. Subunit 4c contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including clay soils and loamy soils underlain by a clay subsoil (PCE 1A), and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports a stable, persistent occurrence. The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from the indirect effects associated with urban development. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations. We are considering this subunit for exclusion under section 4(b)(2) of the Act because this subunit is within the area addressed by the Orange County Southern Subregion HCP; please see the

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 4g: Cristianitos Canyon

Subunit 4g consists of 587 ac (238 ha) of privately owned land in Cristianitos Canyon on Rancho Mission Viejo in southern Orange County. Lands within this subunit are underlain by clay and sandy loam soils and consist primarily of annual grassland and needlegrass grassland. Subunit 4g contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including clay soils and loamy soils underlain by a clay subsoil (PCE 1A), and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); (2) supports an occurrence in rare and unique habitat, representing one of the few places where this species occurs in needlegrass grassland in Orange County; and (3) supports an occurrence of at least 6,505 individuals of

B. filifolia

, as documented in 2003 (Dudek and Associates, Inc. 2006, Chapter 3 pp. 73-74, 83; Service 2007, pp. 149-150). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from the indirect effects associated with urban development. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Unit 5: Northern San Diego County

- Devil Canyon

Subunit 5b consists of 266 ac (108 ha) Federal land (Cleveland National Forest) and 8 ac (3 ha) of private land in northern San Diego County. Lands within this subunit contain Cieneba Very Rocky Coarse Sandy Loam, Fallbrook Sandy Loam, and Cieneba Coarse Sandy Loam soils and consist primarily of chaparral and oak woodland vegetation. Subunit 5b contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including sandy loam soils (PCE 1E) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); (2) supports an occurrence in rare and unique habitat, representing one of the few places where this species occurs in a drainage in oak woodland habitat and occurring in unusual seeps and drainages on low granitic outcrops; and (3) supports a stable, persistent occurrence. The Cleveland National Forest does not currently have a management plan specific to

B. filifolia

; however, timing of cattle grazing has been adjusted to avoid the flowering period for the species (Winter 2004, pers. comm.). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Unit 6: Oceanside, San Diego County

Unit 6 is located in Oceanside, San Diego County and consists of five subunits totaling 231 ac (93 ha) of private land.

Subunit 6a: Alta Creek

Subunit 6a consists of 72 ac (29 ha) of private land in the City of Oceanside, in northern coastal San Diego County. This subunit was not included in the 2005 final critical habitat designation but is included in this proposed rule based on new information related to the distribution of

Brodiaea filifolia

. Lands within this subunit contain fine sandy loam, loam, or loamy fine sand and consist primarily of coastal sage scrub habitat. Subunit 6a contains the physical and biological features essential to the conservation of

B. filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

indirect effects associated with urban development. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Subunit 6b: Mesa Drive

Subunit 6b consists of 17 ac (7 ha) of private land in the City of Oceanside, in northern coastal San Diego County. Lands within this subunit contain loamy fine sands and consist primarily of grassland habitat. Subunit 6b contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports a stable, persistent occurrence. The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from the indirect effects associated with urban development and habitat disturbance on local government lands (Roberts 2005, pp. 1-3). Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Subunit 6c: Mission View/ Sierra Ridge

Subunit 6c consists of 12 ac (5 ha) of private land in the City of Oceanside, in northern coastal San Diego County. This subunit was not included in the 2005 final critical habitat designation but is included in this proposed rule based on new information related to the distribution of

Brodiaea filifolia

. Lands within this subunit contain fine loamy sands and consist primarily of coastal sage scrub habitat. Subunit 6c contains the physical and biological features essential to the conservation of

B. filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

habitat and potential management considerations.

Subunit 6d: Taylor/Darwin

Subunit 6d consists of 35 ac (14 ha) of private land in the City of Oceanside, in northern coastal San Diego County. Lands within this subunit contain clay soil and fine loamy sands and consist primarily of annual and needlegrass grassland. Subunit 6d contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports an occurrence of at least 6,200 individuals of

B. filifolia

, as documented in 2005 (CNDDB 2009, p. 38). The site is conserved and will not be developed (Helix Environmental Planning, Inc. 2004, p. 5-13). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Subunit 6e: Arbor Creek/Colucci

Subunit 6e consists of 94 ac (38 ha) of private land in the City of Oceanside, in northern coastal San Diego County. This subunit was not included in the 2005 final critical habitat designation but is included in this proposed rule based on new information related to the distribution of

Brodiaea filifolia

. Lands within this subunit contain clay soil and fine loamy sands and consist primarily of annual and needlegrass grassland. Subunit 6e contains the physical and biological features essential to the conservation of

B. filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports a stable, persistent occurrence, which occurs in the largest continuous block of grassland habitat remaining in City of Oceanside. The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants and urban development. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Unit 7: Carlsbad, San Diego County

Unit 7 is located in Carlsbad, San Diego County and consists of four subunits totaling 263 ac (106 ha) of private land.

Subunit 7a: Letterbox Canyon

Subunit 7a consists of 57 ac (23 ha) of private land in the City of Carlsbad, in northern coastal San Diego County. Lands within this subunit contain heavy clay soils and consist primarily of annual grassland. Subunit 7a contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports an occurrence of at least 39,500 individuals of

B. filifolia

, as documented in 2005 (CNDDB 2009, p. 15). The site is conserved and will be managed and monitored in perpetuity (Service and CDFG 2005, p. 1). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from the indirect effects associated with urban development. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion

Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 7b: Rancho Carrillo

Subunit 7b consists of 37 ac (15 ha) of private land in the City of Carlsbad, in northern coastal San Diego County. This subunit was not included in the 2005 final critical habitat designation but is included in this proposed rule based on new information related to the distribution of

Brodiaea filifolia

. Lands

within this subunit contain clay or sandy loam soils and consist primarily of annual grasslands and coastal sage scrub habitat. Subunit 7b contains the physical and biological features essential to the conservation of

B. filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports an occurrence of at least 797,000 individuals of

B. filifolia

, as documented in 2005 (this estimate was of vegetative plants and not flowering plants) (Scheidt and Allen 2005, p. 1). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from the indirect effects associated with urban development and nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 7c: Calavera Hills Village H

Subunit 7c consists of 71 ac (29 ha) of private land in the City of Carlsbad, in northern coastal San Diego County. Lands within this subunit contain clay soil and consist primarily of annual and needlegrass grassland. Subunit 7c contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports a stable, persistent occurrence of at least 2,243 plants, as documented in 2008 (McConnell 2008, p. 9). The site is conserved and will not be developed (Planning Systems 2002, pp. 8-9). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 7d: Rancho La Costa

Subunit 7d consists of 98 ac (40 ha) of private land in the City of Carlsbad, in northern coastal San Diego County. Lands within this subunit contain clay soil and consist primarily of annual and needlegrass grassland. Subunit 7d contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports an occurrence of at least 13,445 individuals of

B. filifolia

, as documented in 2008 (CNDDB 2009, p. 30). The site is conserved and will not be developed (Center for Natural Lands Management 2005, pp. 1-5). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Unit 8: San Marcos, San Diego County

Unit 8 is located in San Marcos, northern San Diego County and consists of three subunits totaling 108 ac (44 ha) of private land.

Subunit 8b: Rancho Santalina/Loma Alta

Subunit 8b consists of 47 ac (19 ha) of private land in the City of San Marcos, northern San Diego County. This subunit was not included in the 2005 final critical habitat designation but is included in this proposed rule based on new information related to the distribution of

Brodiaea filifolia

. Lands within this subunit contain clay, loam, or loamy fine sand soils and consist primarily of annual and needlegrass grassland. Subunit 8b contains the physical and biological features essential to the conservation of

B. filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports an occurrence of at least 5,552 individuals of

B. filifolia

, as documented in 2000, and approximately 12,000

B. filifolia

corms were transplanted to the area in 2004 (CNDDB 2009, p. 10). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from the indirect effects associated with urban development, unauthorized recreational activities, and nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Subunit 8d: Upham

Subunit 8d consists of 54 ac (22 ha) of private land in the City of San Marcos, northern San Diego County. Lands within this subunit contain clay soils and consist primarily of annual and needlegrass grassland and vernal pool habitat. Subunit 8d contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); (2) supports a rare or unique occurrence, representing one of three occurrences that are associated with vernal pool habitat; and (3) supports an occurrence of at least 342,000 individuals of

B. filifolia

, as documented in 1993 (CNDDB 2009, p. 9). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from the indirect effects associated with urban development, unauthorized recreational

activities, and nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Subunit 8f: Oleander/San Marcos

Subunit 8f consists of 7 ac (3 ha) of land owned by the San Marcos Unified School District near the City of San Marcos, in northern San Diego County. This subunit was not included in the 2005 final critical habitat designation but is included in this proposed rule based on new information related to the distribution of

Brodiaea filifolia

. Lands within this subunit contain clay, loam, or loamy fine sand soils and consist primarily of annual grassland. Unit 8f contains the physical and biological features essential to the conservation of

B. filifolia

because it (1) contains the PCEs for

B. filifolia

, including loamy soils underlain by a clay subsoil (PCE 1A) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports an occurrence of at least 3,802 individuals of

B. filifolia

, as documented in 2005 (Dudek and Associates, Inc. 2005, p. 19). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

habitat and potential management considerations.

Unit 11: Western Riverside County

Unit 11 is located in western Riverside County and consists of eight subunits totaling 1,494 ac (605 ha). This unit contains 53 ac (21 ha) of Federal land, 766 ac (310 ha) of State land, 5 ac (2 ha) of local government land and 670 ac (271 ha) of private land.

Subunit 11a: San Jacinto Wildlife Area

Subunit 11a consists of 385 ac (156 ha) of State land (CDFG) and 16 ac (6 ha) of private land at the San Jacinto Wildlife Area, in western Riverside County. Lands within this subunit contain Willows silty clay, Waukena loam and Waukena fine sandy loam, Traver fine sandy loam and Traver loamy fine sand, and Hanford coarse sandy loam soils and consist primarily of annual grassland, alkali scrub habitat, and alkali playa habitat. Subunit 11a contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including silty loam soils underlain by a clay subsoil or caliche that are generally poorly drained and moderately to strongly alkaline (PCE 1C) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); (2) supports a rare or unique occurrence, representing one of four occurrences associated with alkali playa habitat; and (3) supports a stable, persistent occurrence. The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants and construction of new roads or improvements to existing roadways (Service 2005b, pp. 137, 189). Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 11b: San Jacinto Avenue and Dawson Road

Subunit 11b consists of 117 ac (47 ha) of private land near San Jacinto Avenue and Dawson Road, in western Riverside County. Lands within this subunit contain Willows silty clay and Domino silt loam soils and consist primarily of annual grassland, alkali scrub habitat, and alkali playa habitat. Subunit 11b contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

and pollinator habitat (PCE 2); and (2) supports a rare or unique occurrence, representing one of four occurrences that are associated with alkali playa habitat. The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from discing, grazing, manure dumping, and nonnative invasive plants (CNDDB 2009, p. 60). Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 11c: Case Road

Subunit 11c consists of 180 ac (73 ha) of private land west of I-215, near the City of Perris, in western Riverside County. Lands within this subunit contain Willows silty clay and Domino silt loam soils and consist primarily of agricultural land, floodplain habitat, alkali scrub habitat, and alkali playa habitat. Subunit 11c contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

and pollinator habitat (PCE 2); (2) supports a rare or unique occurrence, representing one of four occurrences that are associated with alkali playa habitat; and (3) supports an occurrence of at least 4,555 individuals of

B. filifolia

, as documented in 2000 (Glenn Lukos Associates, Inc. 2000a, Map of San Jacinto River Stage 3 Project Impacts Version 2 Alignment; Glenn Lukos Associates, Inc. 2000b, pp. 17-18; CNDDB 2009, p. 2). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from OHV activity, encroaching urban development, manure dumping, and nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion

Under Section 4(b)(2) of the Act

section of this

proposed rule for a discussion about our consideration to exclude this area.

Subunit 11d: Railroad Canyon

Subunit 11d consists of 53 ac (21 ha) of Federal land owned by the Bureau of Land Management and 205 ac (83 ha) of private land north of Kabian County Park and southwest of the City of Perris, in western Riverside County. Lands within this subunit contain Lodo rocky loam, Garretson gravelly very fine sandy loam and Garretson very fine sandy loam, Escondido fine sandy loam, and Grangeville fine sandy loam soils and consist primarily of annual grassland. Subunit 11d contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

and pollinator habitat (PCE 2); and (2) supports an occurrence of at least 3,205 individuals of

B. filifolia

, as documented in 2000 (Glenn Lukos Associates 2000a, pp. 13, 24; CNDDB 2009, p. 23). The occurrence in Railroad Canyon is at risk from the proposed San Jacinto River Flood Control Project. That project includes channelization of the river, which may result in changes in floodplain process essential to the species persistence in this subunit (Service 2004b, p. 382). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from the indirect effects associated with urban development, river channelization for flood control, and nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 11e: Upper Salt Creek (Stowe Pool)

Subunit 11e consists 145 ac (59 ha) of private land in the Upper Salt Creek drainage west of Hemet, in western Riverside County. Lands within this subunit contain Willows silty clay, Chino silt loam, Honcut loam, and Wyman loam and consist primarily of annual grassland, alkali scrub habitat, and alkali playa habitat. Subunit 11e contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including silty loam soils underlain by a clay subsoil or caliche that are generally poorly drained and moderately to strongly alkaline (PCE 1C), and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports a rare or unique occurrence, representing one of three occurrences that are associated with vernal pool habitat. This subunit is crossed by roadways that, if altered (widened or realigned), could change the topography and thereby negatively affect the hydrologic integrity of the pool complexes and favor the growth of nonnative invasive plant species (CNDDB 2009, p. 24; Service 2004b, p. 382). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants and transportation projects. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 11f: Santa Rosa Plateau - Mesa de Colorado

Subunit 11f consists of 221 ac (89 ha) of State-owned land, 5 ac (2 ac) of local government land and 8 ac (3 ha) of private land on the Santa Rosa Plateau, in southwestern Riverside County. Lands within this subunit contain Murrieta stony clay loam, and Las Posas rocky loam and Las Posas loam soils and consist primarily of annual and needlegrass grassland and vernal pool habitat. Subunit 11f contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including clay loam soil series underlain by heavy clay loams or clays derived from olivine basalt lava flows that generally occur on mesas and gentle to moderate slopes (PCE 1D) and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

, as documented in 1990 (CNDDB 2009, p. 5). The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from the indirect effects associated with urban development and nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 11g: Santa Rosa Plateau - South of Tenaja Road

Subunit 11g consists of 117 ac (47 ha) of State-owned land on the Santa Rosa Plateau, in southwestern Riverside County. Lands within this subunit contain Murrieta stony clay loam, and Las Posas rocky loam and Las Posas loam soils and consist primarily of annual and needlegrass grassland and vernal pool habitat. Subunit 11g contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

and pollinator habitat (PCE 2); and (2) supports a rare or unique occurrence, occurring along an ephemeral drainage in seep type habitats. The physical and biological features essential to the conservation of the species in this subunit may require special management considerations or protection to address threats from nonnative invasive plants. Please see the “Special Management Considerations or Protection” section of

this proposed rule for a discussion of the threats to

B. filifolia

Areas Considered for Exclusion Under Section 4(b)(2) of the Act

section of this proposed rule for a discussion about our consideration to exclude this area.

Subunit 11h: Santa Rosa Plateau - North of Tenaja Road

Subunit 11h consists of 44 ac (18 ha) of State-owned land on the Santa Rosa Plateau, in southwestern Riverside County. Lands within this subunit contain Murrieta stony clay loam, and Las Posas rocky loam and Las Posas loam soils and consist primarily of annual and needlegrass grassland and vernal pool habitat. Subunit 11h contains the physical and biological features essential to the conservation of

Brodiaea filifolia

because it (1) contains the PCEs for

B. filifolia

, including clay loam soil series underlain by heavy clay loams or clays derived from olivine basalt lava flows that generally occur on mesas and gentle to moderate slopes (PCE 1D), and areas with a natural, generally intact surface and subsurface soil structure that support

B. filifolia

and pollinator habitat (PCE 2); and (2) supports a rare or unique occurrence, occurring along an ephemeral drainage in seep type habitats. The physical and biological features essential to the

This text is long and has been trimmed here. Open the source document for the complete record.

This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.