# Endangered and Threatened Wildlife and Plants; Final Revised Critical Habitat for Brodiaea filifolia (Thread-Leaved Brodiaea) > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2011-2403 ## Record - **Collection:** Federal Register - **Document type:** Rule - **Published:** February 8, 2011 - **Citation:** 76 FR 6848 ## Text DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R8-ES-2009-0073; MO 92210-0-0009] RIN 1018-AW54 Endangered and Threatened Wildlife and Plants; Final Revised Critical Habitat for Brodiaea filifolia (Thread-Leaved Brodiaea) AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: We, the U.S. Fish and Wildlife Service, are designating revised critical habitat for Brodiaea filifolia (thread-leaved brodiaea) under the Endangered Species Act of 1973, as amended (Act). Approximately 2,947 acres (ac) (1,193 hectares (ha)) in 10 units are being designated as revised critical habitat for B. filifolia in Los Angeles, San Bernardino, Riverside, Orange, and San Diego Counties, California. DATES: This rule becomes effective on March 10, 2011. ADDRESSES: The final rule, final economic analysis, and map of revised critical habitat will be available on the Internet at http://www.regulations. gov at Docket No. FWS-R8-ES-2009-0073. Supporting documentation we used in preparing this final rule will be available for public inspection, by appointment, during normal business hours, at the 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. FOR FURTHER INFORMATION CONTACT: Jim Bartel, Field Supervisor, U.S. Fish and Wildlife Service, Carlsbad Fish and Wildlife Office ( see ADDRESSES ). If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-877-8339. SUPPLEMENTARY INFORMATION: Background We intend to discuss only those topics directly relevant to the designation of revised critical habitat for Brodiaea filifolia under the Endangered Species Act (Act), as amended (16 U.S.C. 1531 et seq. ), in this final rule. For information on the taxonomy, biology, and ecology of B. filifolia, refer to the final listing rule published in the Federal Register on October 13, 1998 (63 FR 54975), the designation of critical habitat for B. filifolia published in the Federal Register on December 13, 2005 (70 FR 73820), the proposed revised designation of critical habitat published in the Federal Register on December 8, 2009 (74 FR 64930), and the Notice of Availability (NOA) of the draft economic analysis (DEA) published in the Federal Register on July 20, 2010 (75 FR 42054). 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. New Information on Species' Description, Life History, Ecology, Habitat, and Geographic Range and Status We received no new information pertaining to the description, life history, ecology, habitat, geographic range, or status of Brodiaea filifolia following the 2009 proposed revised critical habitat designation (74 FR 64930). Previous Federal Actions We published our final designation of critical habitat for Brodiaea filifolia on December 13, 2005 (70 FR 73820). The Center for Biological Diversity filed a complaint in the U.S. District Court for the Southern District of California on December 19, 2007, challenging our designation of critical habitat for B. filifolia and Navarretia fossalis ( Center for Biological Diversity v. United States Fish and Wildlife, et al., Case No. 07-CV-02379-W-NLS). In a settlement agreement dated July 25, 2008, we agreed to reconsider the critical habitat designation for B. filifolia. The settlement stipulated that the U.S. Fish and Wildlife Service (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. The proposed revised critical habitat designation was published in the Federal Register on December 8, 2009 (74 FR 64930). On November 19, 2010, the U.S. District Court granted a motion to modify the settlement agreement to extend to January 31, 2011, submittal of a final revised critical habitat designation to the Federal Register . Summary of Changes From the Proposed Revised Rule and the Previous Critical Habitat Designation Summary of Changes From the 2005 Critical Habitat Rule The areas identified in this rule constitute a 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. In the 2005 rule, we excluded subunits under section 4(b)(2) of the Act within the planning boundaries for the Villages of La Costa Habitat Conservation Plan (HCP). The Villages of La Costa HCP is now included within (considered part of) the City of Carlsbad's Habitat Management Plan (Carlsbad HMP) under the Multiple Habitat Conservation Plan (MHCP); therefore, all revised critical habitat that overlaps with the Villages of La Costa HCP was analyzed under section 4(b)(2) of the Act as part of the Carlsbad HMP discussion. These areas have again been excluded from this revised designation under section 4(b)(2) of the Act ( see Exclusions Under Section 4(b)(2) of the Act section below). In the 2005 rule, we identified areas covered by HCPs that provided protections for Brodiaea filifolia, and excluded those areas because we concluded they did not require special management considerations or protection. We are not using this approach in this rule. In this rule, we identified areas covered by HCPs that are conserved and managed and have weighed the benefits of exclusion against the benefits of including these areas in the revised critical habitat designation pursuant to section 4(b)(2) of the Act. This rule uses a new economic analysis to identify and estimate the potential economic effects resulting from implementation of conservation actions associated with the revised critical habitat. The analysis is based on estimated incremental impacts associated with critical habitat. We made changes to the primary constituent elements (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 Brodiaea filifolia. We redefined the boundaries of each subunit proposed as revised 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 (in the 2009 proposed revised critical habitat rule) that has become available to us following the 2005 designation. Table 1 shows the progression of each subunit of critical habitat from the 2005 final critical habitat designation to this final revised critical habitat designation. Table 2 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 of these units have not changed. Following Tables 2 and 3, we provide a detailed description of each change made in this revised rule and point to new information that precipitated the change. Table 1—Changes Between the December 13, 2005, Final Critical Habitat Designation for Brodiaea filifolia, the December 8, 2009, Proposed Revised Critical Habitat Designation, and This Final Revised Critical Habitat Designation * Unit/Subunit No. and name ** 2005 fCH 2009 prCH 2011 frCH Unit 1: Los Angeles County: 1a. Glendora 96 ac (39 ha) 67 ac (27 ha) 67 ac (27 ha). 1b. San Dimas 198 ac (80 ha) 138 ac (56 ha) 138 ac (56 ha). Unit 2: San Bernardino County: 2. Arrowhead Hot Springs Not designated, wrong location 61 ac (25 ha) 61 ac (25 ha). Unit 3: Central Orange County: 3. Aliso Canyon Not designated, did not meet the definition of critical habitat 113 ac (46 ha) 11 ac (4 ha); partially excluded under section 4(b)(2). Unit 4: Southern Orange County: 4a. Arroyo Trabuco Not designated, did not meet the definition of critical habitat N/A N/A. 4b. Caspers Wilderness Park Excluded under section 4(b)(2) 205 ac (83 ha) 12 ac (5 ha); partially excluded under section 4(b)(2). 4c. Cañada Gobernadora/Chiquita Ridgeline Excluded under section 4(b)(2) 133 ac (54 ha) 133 ac (54 ha). 4d. Prima Deschecha Not designated, did not meet the definition of critical habitat N/A N/A. 4e. Forster Ranch Not designated, did not meet the definition of critical habitat N/A N/A. 4f. Talega/Segunda Deshecha Not designated, did not meet the definition of critical habitat N/A N/A. 4g. Cristianitos Canyon Excluded under section 4(b)(2) 587 ac (238 ha) 587 ac (238 ha). 4h. Cristianitos Canyon South Not designated, did not meet the definition of critical habitat N/A N/A. 4i. Blind Canyon Not designated, did not meet the definition of critical habitat N/A N/A. Unit 5: Northern San Diego County: 5a. Miller Mountain Not designated, mostly hybrid plants Not proposed, only Brodiaea santarosae present N/A. 5b. Devil Canyon 249 ac (101 ha) 274 ac (111 ha) 274 ac (111 ha). Unit 6: Oceanside: 6a. Alta Creek Not designated, did not meet the definition of critical habitat 72 ac (29 ha) 72 ac (29 ha). 6b. Mesa Drive Excluded under section 4(b)(2) 17 ac (7 ha) 17 ac (7 ha). 6c. Mission View/Sierra Ridge Not designated, did not meet the definition of critical habitat 12 ac (5 ha) 12 ac (5 ha). 6d. Taylor/Darwin Excluded under section 4(b)(2) 35 ac (14 ha) 35 ac (14 ha). 6e. Arbor Creek/Colucci N/A 94 ac (38 ha) 94 ac (38 ha). Unit 7: Carlsbad 7a. Letterbox Canyon Excluded under section 4(b)(2) 57 ac (23 ha) 43 ac (17 ha); partially excluded under section 4(b)(2); 2 ac (1 ha) removed—do not meet the definition of critical habitat. 7b. Rancho Carrillo Not designated, did not meet the definition of critical habitat 37 ac (15 ha) 37 ac (15 ha). 7c. Calavera Hills Village H Excluded under section 4(b)(2) 71 ac (29 ha) 26 ac (11 ha); partially excluded under section 4(b)(2). 7d. Villages of La Costa (Rancho La Costa) Excluded under section 4(b)(2) 98 ac (40 ha) Excluded under section 4(b)(2). Carlsbad Oaks Excluded under section 4(b)(2) Not proposed, does not meet the definition of critical habitat N/A. Carlsbad Highlands Excluded under section 4(b)(2) Not proposed, does not meet the definition of critical habitat N/A. Poinsettia Excluded under section 4(b)(2) Not proposed, does not meet the definition of critical habitat N/A. Unit 8: San Marcos and Vista: 8a. Rancho Santa Fe Road North Not designated, did not meet the definition of critical habitat N/A N/A. 8b. Rancho Santalina/Loma Alta Not included under section 3(5)(A) 47 ac (19 ha) 47 ac (19 ha). 8c. Grand Avenue Not designated, did not meet the definition of critical habitat N/A N/A. 8d. Upham 54 ac (22 ha) 54 ac (22 ha) 54 ac (22 ha). 8e. Linda Vista Not designated, did not meet the definition of critical habitat N/A N/A. 8f. Oleander/San Marcos Elementary N/A 7 ac (3 ha) 7 ac (3 ha). Unit 9: 9. Double LL Ranch Not designated, did not meet the definition of critical habitat N/A N/A. Unit 10: 10. Highland Valley Not designated; could not verify occurrence N/A N/A. Unit 11: Western Riverside County: 11a. San Jacinto Wildlife Area Excluded under section 4(b)(2) 401 ac (162 ha) 401 ac (162 ha). 11b. San Jacinto Avenue/Dawson Road Excluded under section 4(b)(2) 117 ac (47 ha) 117 ac (47 ha). 11c. Case Road Excluded under section 4(b)(2) 180 ac (73 ha) 180 ac (73 ha). 11d. Railroad Canyon Excluded under section 4(b)(2) 257 ac (104 ha) 257 ac (104 ha). 11e. Upper Salt Creek (Stowe Pool) Excluded under section 4(b)(2) 145 ac (59 ha) 145 ac (59 ha). 11f. Santa Rosa Plateau—Mesa de Colorado Excluded under section 4(b)(2) 234 ac (95 ha) 13 ac (5 ha); partially excluded under section 4(b)(2). Santa Rosa Plateau—Tenaja Rd Excluded under section 4(b)(2) Not proposed; only Brodiaea santarosae present N/A. 11g. Santa Rosa Plateau—South of Tenaja Rd Excluded under section 4(b)(2) 117 ac (47 ha) Excluded under section 4(b)(2). 11h. Santa Rosa Plateau—North of Tenaja Rd Excluded under section 4(b)(2) 44 ac (18 ha) Excluded under section 4(b)(2). East of Tenaja Guard Station Excluded under section 4(b)(2) Not proposed, does not meet the definition of critical habitat N/A. N. End Redondo Mesa Excluded under section 4(b)(2) Not proposed, does not meet the definition of critical habitat N/A. Corona (north) Not designated, could not verify occurrence N/A N/A. Corona (south) Not designated, could not verify occurrence N/A N/A. Moreno Valley Not designated, could not verify occurrence N/A N/A. Unit 12: San Diego County: 12. Artesian Trails N/A 109 ac (44 ha) 105 ac (43 ha); partially excluded under section 4(b)(2). TOTAL FOR NON-MILITARY LANDS 597 ac (242 ha) 3,786 ac (1,532 ha) 2,945 ac (1,193 ha) . Marine Corps Base Camp Pendleton: Cristianitos Canyon Pendleton N/A 4(a)(3) exemption 4(a)(3) exemption. Bravo One 4(a)(3) exemption 4(a)(3) exemption 4(a)(3) exemption. Bravo Two South N/A 4(a)(3) exemption 4(a)(3) exemption. Alpha One/Bravo Three 4(a)(3) exemption Does not meet the definition of critical habitat N/A. Basilone/San Mateo Junction N/A 4(a)(3) exemption 4(a)(3) exemption. Camp Horno 4(a)(3) exemption 4(a)(3) exemption 4(a)(3) exemption. SE Horno Summit 4(a)(3) exemption Does not meet the definition of critical habitat N/A. Kilo One 4(a)(3) exemption Does not meet the definition of critical habitat N/A. Pilgrim Creek N/A 4(a)(3) exemption 4(a)(3) exemption. South White Beach N/A 4(a)(3) exemption 4(a)(3) exemption. TOTAL FOR MILITARY LANDS *** 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) . TOTALS 597 ac (242 ha) 3,786 ac (1,532 ha) 2,947 ac (1,193 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 and the following text may not sum due to rounding. *** Military Lands are exempt from this rule under section 4(a)(3) of the Act. Table 2—Name Changes From the 2005 Final Critical Habitat Designation for Brodiaea filifolia to This Final Revised Critical Habitat Designation Subunit No. Previous name Current name Reason for change 6c Oceanside East/Mission Ave Mission View/Sierra Ridge Not the eastern most occurrence in Oceanside. 7a Fox-Miller Letterbox Canyon Includes more properties than just Fox-Miller. 7c 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. Summary of Changes From the 2009 Proposed Revised Critical Habitat Rule The most significant changes between the December 2009 proposed revision and this final revised rule are outlined in Table 1 above and include: (1) In the proposed revised rule, we considered lands covered by the Southern Subregion Natural Community Conservation Plan/Master Streambed Alteration Agreement/Habitat Conservation Plan, now known as the Orange County Southern Subregion HCP, for exclusion under section 4(b)(2) of the Act. We have now analyzed each of the areas considered for exclusion under the Orange County Southern Subregion HCP, and have determined that the benefits of exclusion outweigh the benefits of inclusion for approximately 192 ac (78 ha) of proposed revised critical habitat in Subunit 4b that are covered by the Orange County Southern Subregion HCP and are conserved and managed. We also determined that exclusion of these areas will not result in extinction of the species. Therefore, we are exercising our delegated discretion to exclude these lands from this revised critical habitat designation under section 4(b)(2) of the Act. For a complete discussion of the benefits of inclusion and exclusion, see Exclusions Under Section 4(b)(2) of the Act section below. (2) In the proposed revised rule, we considered lands covered by the Carlsbad Habitat Management Plan (HMP) under the San Diego Multiple Habitat Conservation Program (MHCP) for exclusion under section 4(b)(2) of the Act. We have now analyzed each of the areas considered for exclusion under the Carlsbad HMP, and have determined that the benefits of exclusion outweigh the benefits of inclusion for approximately 156 ac (63 ha) of proposed revised critical habitat in Subunits 7a, 7c, and 7d that are covered by the Carlsbad HMP under the MHCP and are conserved and managed. We also determined that exclusion of these areas will not result in extinction of the species. Therefore, we are exercising our delegated discretion to exclude these lands from this revised critical habitat designation under section 4(b)(2) of the Act. For a complete discussion of the benefits of inclusion and exclusion, see Exclusions Under Section 4(b)(2) of the Act section below. (3) We have determined that 2 ac (1 ha) of land in Subunit 7a do not meet the definition of critical habitat for Brodiaea filifolia because they do not contain habitat suitable for the species. We are therefore not including these areas in the revised critical habitat designation. (4) In the proposed revised rule, we considered lands within the Western Riverside County Multiple Species Habitat Conservation Plan (Western Riverside County MSHCP) planning area for exclusion under section 4(b)(2) of the Act. We have now analyzed each of the areas considered for exclusion under the Western Riverside County MSHCP, and have determined that the benefits of exclusion outweigh the benefits of inclusion for approximately 381 ac (154 ha) of proposed revised critical habitat in Subunits 11g, 11h, and a portion of Subunit 11f that are covered by the Western Riverside County MSHCP and are conserved and managed. We also determined that exclusion of these lands will not result in extinction of the species. Therefore, we are exercising our delegated discretion to exclude these lands from this revised critical habitat designation under section 4(b)(2) of the Act. For a complete discussion of the benefits of inclusion and exclusion, see Exclusions Under Section 4(b)(2) of the Act section below. (5) In the proposed revised rule, we considered lands covered by the San Diego Multiple Species Conservation Program (MSCP) for exclusion under section 4(b)(2) of the Act. We have now analyzed each of the areas considered for exclusion under the MSCP, and have determined that the benefits of exclusion outweigh the benefits of inclusion for approximately 4 ac (2 ha) of proposed revised critical habitat in Unit 12 that are under the County of San Diego Subarea Plan and are conserved and managed. We also determined that exclusion of these lands will not result in extinction of the species. Therefore, we are exercising our delegated discretion to exclude these lands from this revised critical habitat designation under section 4(b)(2) of the Act. For a complete discussion of the benefits of inclusion and exclusion, see Exclusions Under Section 4(b)(2) of the Act section below. (6) A number of comments we received suggested editorial changes and technical corrections to sections of the rule pertaining to the Background and Criteria Used To Identify Critical Habitat sections of the proposed revised rule. These changes were recommended to improve clarity, include additional information, and correct minor errors. They have been incorporated into this final rule, where appropriate. Critical Habitat Background Critical habitat is defined in section 3(5)(A) of the Act as: (1) The specific areas within the geographical area occupied by the species, at the time it is listed in accordance with the Act, on which are found those physical or biological features: (a) Essential to the conservation of the species and (b) Which may require special management considerations or protection; and (2) Specific areas outside the geographical area occupied by the species at the time it is listed, upon a determination that such areas are essential for the conservation of the species. Conservation, as defined under section 3 of the Act, means 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 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) of the Act requires consultation on Federal actions that may affect critical habitat. The designation of critical habitat does not affect land ownership or establish a refuge, wilderness, reserve, preserve, or other conservation area. Such designation does not allow the government or public to access private lands. Such designation does not require implementation of restoration, recovery, or enhancement measures by private landowners. Where a landowner requests Federal agency funding or authorization for an action that may affect a listed species or critical habitat, the consultation requirements of section 7(a)(2) would apply, but even in the event of a destruction or adverse modification finding, the landowner's obligation is not to restore or recover the species, but to implement reasonable and prudent alternatives to avoid destruction or adverse modification of critical habitat. For inclusion in a critical habitat designation, the habitat within the geographical area occupied by the species at the time of listing must contain physical or 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. The physical and biological features are the primary constituent elements (PCEs) laid out in the appropriate quantity and spatial arrangement essential to the conservation of the species. Critical habitat designations identify, to the extent known using the best scientific data available, habitat areas that provide essential life cycle needs of the species ( i.e., areas on which are found the 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 as critical habitat only when we determine that those areas are essential for the conservation of the species and that designation limited to the geographical area occupied at the time of listing 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 (44 U.S.C. 3516), and our associated Information Quality Guidelines, provide criteria, establish procedures, and provide guidance to ensure that our decisions are based on the best scientific and commercial data available. They require our biologists, to the extent consistent with the Act and with the use of the best scientific and commercial 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. Substantive comments received in response to proposed critical habitat designations are also considered. Habitat is often dynamic, and species may move from one area to another over time. Climate change will be a particular challenge for biodiversity because the interaction of additional stressors associated with climate change and current stressors may push species beyond their ability to survive (Lovejoy 2005, pp. 325-326). The synergistic implications of climate change and habitat fragmentation are the most threatening facet of climate change for biodiversity (Hannah et al. 2005, p. 4). 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 (IPCC) 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 could affect a number of native plants, including 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 germination rate and smaller population sizes; (2) A shift in the timing of 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 or native plant invasion. At this time, we are unable to identify the specific ways that climate change may impact Brodiaea filifolia; therefore, we are unable to determine if any additional areas may be appropriate to include in this revised critical habitat designation. 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 of the species, 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. In these areas, the species is also subject to the regulatory protections afforded by the section 7(a)(2) jeopardy standard, as determined on the basis of the best scientific and commercial information available 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, HCPs, or other species conservation planning efforts if new information available to these planning efforts calls for a different outcome. Primary Constituent Elements Physical and Biological Features In accordance with section 3(5)(A)(i) of the Act and regulations at 50 CFR 424.12(b), in determining which areas occupied by the species at the time of listing to designate as critical habitat, we consider those physical or biological features that are essential to the conservation of the species that may require special management considerations or protection. We consider the physical or 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 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 the proposed revised rule (74 FR 64930; December 8, 2009), 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, scrub, or riparian herb 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 most (if not all) of these are primarily clay soils with varying amounts of sand and silt. In this 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. In some areas in northern San Diego County and southwestern Riverside County, the species is identified with mapped soils with no known clay component; however, closer study and sight specific sampling may show these soils contain clay in the specific areas supporting B. filifolia. Despite this issue and the diversity in named soil series, B. filifolia is considered a clay soils endemic. 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 Geographic Information System (GIS) data 2009; USDA 1994). 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 2009a, Service GIS data). These soils are generally vegetated with open native and nonnative grassland, 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 grassland, 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 2009a, Service GIS data). 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 grassland 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. 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. 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 of this species 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, perhaps lightly impacted, but not permanently altered by anthropogenic land use activities (such as deep, repetitive discing, or grading), and associated physical processes such as a natural 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 B. 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 to 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)) 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 B. 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 1,500 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, Holitus, and Osmia (mason bees), 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 2,640 ft (804 m) (Shepherd 2009, pers. comm.). These flight distances are important in determining what habitat associated with B. 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 B. 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 B. 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 conservation of B. filifolia. Including habitat extending beyond the perimeters of mapped occurrences of B. filifolia by up to 820 ft (250 m) 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 Under the Act and its implementing regulations, we are required to identify the physical or biological features essential to the conservation of Brodiaea filifolia and that may require special management considerations or protection. The physical or biological features essential to the conservation of the species are those PCEs laid out in an appropriate quantity and spatial arrangement determined to be essential to the conservation of the species. All final revised critical habitat areas 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 of the species ( see the Spatial Distribution and Historical Range section of the proposed revised 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 to provide for space for individual population growth, and space for pollinators. This revision to the previous 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 revised critical habitat contain one of the specific soil components identified in PCE 1, which 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 ( see Habitat section of the proposed revised critical habitat rule for this species (74 FR 64932)), and have natural, generally intact surface and subsurface soil structure necessary to provide water, minerals, and other physiological needs for the species and support habitat for pollinators, which facilitate reproduction, as identified in PCE 2. These two factors are sufficient to support life-history traits of Brodiaea filifolia in the units/subunits we designate as revised critical habitat. In general, we designate 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 or 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 designated as revised 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 designated as revised 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; dumping of manure and sewage sludge; and hybridization with other species of Brodiaea. 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). Conservation and management of B. filifolia habitat and adjacent pollinator habitat is needed to address the threat of development. 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. Management activities including (but not limited to) nonnative plant removal and control are needed to reduce this threat. 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. Management activities such as (but not limited to) fencing or other barriers to unauthorized access, signage, and monitoring are needed to address this threat. 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). Management activities such as (but not limited to) fencing, signage, and education of landowners and land managers about the detrimental effects that mowing, discing, and dumping sewage have on B. filifolia and its habitat are needed to address this threat. Manure dumping on private property along the San Jacinto River area is impacting habitat within the Western Riverside County MSHCP plan area. These impacts are occurring despite identification of these areas as important for the survival and recovery of Brodiaea filifolia in the Western Riverside County MSHCP. Manure dumping is not a covered activity under the Western Riverside County MSHCP and was not discussed as an impact to B. filifolia in the Biological Opinion on the Western Riverside County MSHCP (Service 2004b, pp. 378-386). As outlined in the Western Riverside County MSHCP, we have been working with permittees to implement additional ordinances that will help to control activities (such as manure dumping) that may impact the implementation of the Western Riverside County MSHCP conservation objectives. To date, the City of Hemet is the only Western Riverside County MSHCP permittee that has addressed the negative impacts that manure dumping has on species such as B. filifolia and Navarretia fossalis and their habitats through the enactment of Ordinance 1666 ( i.e., the ordinance that prevents manure dumping activities and educates its citizens). We will continue to work with Riverside County and permittees of the Western Riverside County MSHCP to address activities that may impact the species within the Western Riverside County MSHCP plan area. The Service is aware of occurrences of some hybrids within the range of Brodiaea filifolia in Subunit 5b (Devil Canyon) in northwestern San Diego County (Chester et al. 2007, p. 193). The presumed parent taxa of these hybrids are considered to be B. filifolia and B. orcuttii because of the apparent morphological intermediacy of the individuals and proximity of their ranges. This is supported by the close relationship of the two species noted above. Although there are some hybrids of B. filifolia and B. orcuttii in this subunit, it is likely that a minimum of 850 plants are pure B. filifolia (Service 2009b, p. 15) (we consider occurrences that have between 850 and 3,000 flowering stems 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 (see Criteria Used section below)). Plants of hybrid origin have also been reported in Subunit 8d (Upham) in the City of San Marcos (Chester et al. 2007, p. 191). Chester et al. (2007) only found a few hybrid specimens at this location, therefore it is likely that a minimum of 850 plants are pure B. filifolia. Hybridization could result in the loss of portions of B. filifolia occurrences if other Brodiaea species are transplanted adjacent to existing B. filifolia occurrences, or if existing B. filifolia occurrences are transplanted adjacent to other Brodiaea species and the two species are able to hybridize. Informing biological resource managers of the existence of this threat will help to keep human-mediated hybridization from occurring. In summary, we find that the areas we are designating as revised critical habitat contain the physical or biological 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 revised 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 revised 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 determined that all areas we are designating as final revised critical habitat are within the geographical area occupied by Brodiaea filifolia at the time of listing and are currently occupied ( see the Spatial Distribution and Historical Range section of the proposed revised critical habitat rule (74 FR 64929; December 8, 2009) for more information). We considered the areas outside the geographical area occupied by the species at the time of listing, but are not designating 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 designated as revised critical habitat contain the 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) of the Act, we use the best scientific and commercial data available in determining areas that contain the physical or biological features that are essential to the conservation of Brodiaea filifolia. The data used for this revised critical habitat are summarized below. This 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 final rule reflects a progression of conservation efforts for Brodiaea filifolia that is largely based 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, the 2005 final critical habitat designation, and new information we obtained on the species' distribution since listing. For some areas that were analyzed in 2005 but determined not to meet the definition of critical habitat, we received new distribution information for the proposed revised rule that resulted in determining that those areas do meet the definition of critical habitat. There are also some areas identified as meeting the definition of critical habitat in the 2005 critical habitat designation that we did not include in the proposed revised rule and this final revised critical habitat designation 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 the Proposed Revised Rule and the Previous Critical Habitat Designation 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; Hamrick and Godt 1996, pp. 291-295; Fraser 2000, pp. 49-51). 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 Millar and Libby 1991, pp. 150, 152-155; or Hamrick and Godt 1996, pp. 299-301). 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 final revised critical habitat designation is occupied by the species at the subunit level, meaning that each subunit contains at least one known occurrence of Brodiaea filifolia. Occupied areas were determined from survey data and element occurrence data in the California Natural Diversity Database (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. The essential features in each subunit are necessary for the conservation of the occurrence within the subunit, which contributes to the overall conservation of the species. To map the areas that meet the definition of critical habitat, we identified areas that contain the PCEs in the appropriate quantity and spatial arrangement 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 Brodiaea 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 B. filifolia is presented in Table 3. We determined that the areas supporting 36 of the 68 extant occurrences meet the definition of critical habitat; of these 36 occurrences, 7 are on Marine Corps Base Camp Pendleton (MCB Camp Pendleton) and the areas are exempt from critical habitat under section 4(a)(3) of the Act ( see Exemptions under Section 4(a)(3) of the Act section below). Of the 29 occurrences in areas proposed as revised critical habitat (74 FR 64930; December 8, 2009), four are in areas excluded from this final revised critical habitat designation under section 4(b)(2) of the Act (Subunits 7d, 8f, 11g, and 11h), and eight are in areas partially excluded from this final revised critical habitat designation under section 4(b)(2) of the Act (portions of Subunits 6a, 6d, 7a, 7c, 8b, 11f, and Units 3 and 12) ( see Exclusions under Section 4(b)(2) of the Act section below). 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 Brodiaea 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 where B. filifolia grows (see Habitat for Pollinators of Brodiaea filifolia section above for a more detailed explanation of pollinator requirements and our derivation of the 820-ft (250-m) distance used to determine the pollinator use area). BILLING CODE 4310-55-P ER08FE11.000 ER08FE11.001 ER08FE11.002 ER08FE11.003 ER08FE11.004 ER08FE11.005 BILLING CODE 4310-55-C 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 (CNF) 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 habitat areas met one or more of the following criteria, they were determined to meet the definition of critical habitat under section 3(5)(A)(i) of the Act. (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; (c) Occurrences that grow along ephemeral drainages in seep-type habitats; and (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 of the 2009 proposed revised critical habitat rule 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 11c-Case Road, Subunit 11d-Railroad Canyon, and Subunit 11f-Santa Rosa Plateau-Mesa de Colorado; (c) Orange County: Unit 3-Aliso Canyon, and Subunit 4g-Cristianitos Canyon; and (d) San Diego County: Subunit 6d-Taylor/Darwin, Subunit 7a-Letterbox Canyon, Subunit 7b-Rancho Carrillo, Subunit 7d-Rancho La Costa, Subunit 8b-Rancho Santalina/Loma Alta, Subunit 8d-Upham, and Subunit 8f-Oleander/San Marcos Elementary ( See Table 1). These large occurrences are present in habitat areas that contain the physical and biological 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 number 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 by providing resilience for the species by decreasing the probability of the species becoming extinct, and by contributing to the genetic diversity of the species. The conservation of these areas helps B. filifolia to maintain its current geographic distribution, since these resilient occurrences are found throughout the range of the species. This is particularly important for B. filifolia because this species relies on outcrossing for successful reproduction. To determine if any additional areas met the third criterion, 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., an occurrence of consistent size not substantially less 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 (Service 2009b), areas supporting 36 occurrences meet one or more of the 3 criteria outlined above. Seven of these areas are exempt from this critical habitat designation under section 4(a)(3) of the Act ( see Exemptions Under Section 4(a)(3) of the Act section), and the remaining 29 areas were proposed as revised critical habitat (74 FR 64930; December 8, 2009). Of these 29 areas, 14 fit into one of the 4 reasons that areas meet the “rare or unique habitat” criterion, 13 meet the “largest occurrences” criterion, and 13 meet the “stable and persistent occurrences” criterion. Of these 29 areas, 3 are excluded from this final revised critical habitat designation under section 4(b)(2) of the Act (Subunits 7d, 11g, and 11h), and 5 are partially excluded from this final revised critical habitat designation under section 4(b)(2) of the Act (portions of Subunits 7a, 7c, 11f, and Units 3 and 12) ( see Exclusions under Section 4(b)(2) of the Act section below). The habitat areas that meet one or more of the criteria represent the historical range of the species, and are adequate to provide for this species' conservation. Habitat areas and the occurrences they support that do not meet any of the three criteria may still be important to the conservation of this species, but without the conservation of the habitat areas and 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 areas supporting 36 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 habitat extending beyond the perimeters of mapped occurrences of Brodiaea filifolia by up to 820 ft (250 m) 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. When determining the final revised critical habitat boundaries for Brodiaea filifolia, we made every effort to map precisely the areas that contain the physical or biological features essential to the conservation of the species. However, we cannot guarantee that every fraction of 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 revised critical habitat are excluded by text in this rule and are not designated critical habitat. 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. Revised Critical Habitat Designation We are designating 2,947 ac (1,193 ha) in 10 units, subdivided into 23 subunits as revised critical habitat for Brodiaea filifolia. The unit numbers in this rule correspond to those used in the 2004 proposed rule and the 2005 final rule; however, Units 9 and 10 were not proposed and Units 11 and 12 are new to this revised 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 partially included based on new occurrence data 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 the Proposed Revised Rule and the Previous Critical Habitat Designation section). The areas we describe below constitute our best assessment of areas that meet the definition of critical habitat for Brodiaea filifolia. We determined these areas are within the geographical area occupied at the time of listing, and contain the physical and biological features essential to the conservation of B. filifolia that may require special management considerations or protection. We are not designating any areas outside the geographical area occupied by the species at the time of listing because we determined that the lands we are designating as revised critical habitat are adequate to ensure conservation of B. filifolia. The lands designated as revised critical habitat represent a subset of the total lands occupied by B. filifolia. Table 4 identifies the approximate area of each designated 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 rule and the 2005 designation), replace the 2005 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 Final Revised Critical Habitat Location Ownership Federal * State government Local government Private Total area ** Unit 1: Los Angeles County 1a. Glendora 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 67 ac (27 ha) 67 ac (27 ha). 1b. San Dimas 13 ac (5 ha) 0 ac (0 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) 0 ac (0 ha) 0 ac (0 ha) 61 ac (25 ha) 61 ac (25 ha). Unit 3: Central Orange County 3. Aliso Canyon 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 11 ac (4 ha) 11 ac (4 ha). Unit 4: Southern Orange County 4b. Caspers Wilderness Park 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 12 ac (5 ha) 12 ac (5 ha). 4c. Cañada Gobernadora/Chiquita Ridgeline 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 133 ac (54 ha) 133 ac (54 ha). 4g. Cristianitos Canyon 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 587ac (238 ha) 587ac (238 ha). Unit 5: Northern San Diego County 5b. Devil Canyon 266 ac (108 ha) 0 ac (0 ha) 0 ac (0 ha) 8 ac (3 ha) 274 ac (111ha). Unit 6: Oceanside 6a. Alta Creek 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 72 ac (29 ha) 72 ac (29 ha). 6b. Mesa Drive 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 17 ac (7 ha) 17 ac (7 ha). 6c. Mission View/Sierra Ridge 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 12 ac (5 ha) 12 ac (5 ha). 6d. Taylor/Darwin 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 35 ac (14 ha) 35 ac (14 ha). 6e. Arbor Creek/Colucci 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 94 ac (38 ha) 94 ac (38 ha). Unit 7: Carlsbad 7a. Letterbox Canyon 0 ac (0 ha) 1 ac (<1 ha) 0 ac (0 ha) 41 ac (17 ha) 43 ac (17 ha). 7b. Rancho Carrillo 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 37 ac (15 ha) 37 ac (15 ha). 7c. Calavera Hills Village H 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 26 ac (11 ha) 26 ac (11 ha). Unit 8: San Marcos and Vista 8b. Rancho Santalina/Loma Alta 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 47 ac (19 ha) 47 ac (19 ha). 8d. Upham 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 54 ac (22 ha) 54 ac (22 ha). 8f. Oleander/San Marcos Elementary 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 7 ac (3 ha) 7 ac (3 ha). Unit 11: Western Riverside County 11a. San Jacinto Wildlife Area 0 ac (0 ha) 366 ac (148 ha) 17 ac (7 ha) 18 ac (7 ha) 401 ac (162 ha). 11b. San Jacinto Avenue/Dawson Road 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 117 ac (47 ha) 117 ac (47 ha). 11c. Case Road 0 ac (0 ha) 0 ac (0 ha) 11 ac (5 ha) 169 ac (68 ha) 180 ac (73 ha). 11d. Railroad Canyon 53 ac (21 ha) 0 ac (0 ha) 1 ac (<1 ha) 204 ac (83 ha) 257 ac (104 ha). 11e. Upper Salt Creek (Stowe Pool) 0 ac (0 ha) 0 ac (0 ha) 0 ac (0 ha) 145 ac (59 ha) 145 ac (59 ha). 11f. Santa Rosa Plateau—Mesa de Colorado 0 ac (0 ha) 0 ac (0 ha) 5 ac (2 ha) 8 ac (3 ha) 13 ac (5 ha). Unit 12: Central San Diego County 12. Artesian Trails 0 ac (0 ha) 0 ac (0 ha) 7 ac (3 ha) 98 ac (40 ha) 105 ac (43 ha). Total** 332 ac (134 ha) 367 ac (148 ha) 41 ac (17 ha) 2,205 ac (894 ha) 2,947 ac (1,193 ha). * 1,531 ac (620 ha) of federally owned land on MCB Camp Pendleton is exempt from this revised critical habitat ( see Exemptions Under Section 4(a)(3) of the Act section). ** Values in this table and the following text 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 which are part of the Transverse Ranges where the species was historically found, and is also significant because it is the northernmost occurrence known; and (3) supports a stable, persistent occurrence of approximately 2,000 plants. 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. The site is protected from development and is owned by the Glendora Community Conservancy (GCC). The GCC has expressed interest in creating a management plan for their land; however, a comprehensive management plan that would specifically address the control of nonnative plants has not been completed at this time. Please see the Special Management Considerations or Protection section of this 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) of 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 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 which are part of the Transverse Ranges where the species was historically found, and represents the only likely genetic connection to plants in the Glendora subunit; and (3) supports two significant populations totaling about 6,000 individuals of B. filifolia, as documented in 1990 (CNDDB 2009, p. 37). Several proposals for development of this area have been reviewed by the City of Glendora (D. Walter, Senior Planner City of Glendora pers. comm. to G. Wallace, Service 2005). Additionally, illegal grading has occurred on the northern portion of this subunit (grading was halted by the City of Glendora). 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, and to maintain pollinator habitat. Please see the Special Management Considerations or Protection section of this 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, California, 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 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 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, California, and consists of 11 ac (4 ha) of private land in the City of Laguna Niguel, southwestern Orange County. These totals do not include 102 ac (42 ha) of land in Unit 3 that we are exercising our delegated discretion to exclude from this revised designation under section 4(b)(2) of the Act ( see the Exclusions under Section 4(b)(2) of the Act section of this rule). This unit was not included in the 2005 final critical habitat designation, but is included in this 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). 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 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, California, and consists of 3 subunits totaling 732 ac (297 ha) of private land. These totals do not include portions of Subunit 4b (192 ac (78 ha)) that we are exercising our delegated discretion to exclude from this revised designation under section 4(b)(2) of the Act ( see the Exclusions under Section 4(b)(2) of the Act section of this rule). Subunits 4a, 4d, 4e, 4f, 4h, and 4i as proposed in the December 8, 2004, rule (69 FR 71283) did not meet the definition of critical habitat and were not proposed for revised designation. Subunit 4b: Wilderness Park Subunit 4b consists of 12 ac (5 ha) of private land in the City of San Juan Capistrano and the Audubon California Starr Ranch Sanctuary, in the southwestern region of the Santa Ana Mountains, southern Orange County. Lands within this 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. 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 rule for a discussion of the threats to B. filifolia habitat and potential management considerations. 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 rule for a discussion of the threats to B. filifolia habitat and potential management considerations. 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 & 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 rule for a discussion of the threats to B. filifolia habitat and potential management considerations. Unit 5: Northern San Diego County Unit 5 is located in northern San Diego County, and consists of one subunit totaling 274 ac (111 ha). This unit contains 266 ac (108 ha) of Federal Government land and 8 ac (3 ha) of private land. This unit is located entirely within the boundary of the CNF. Subunit 5a as proposed in the December 8, 2004, rule (69 FR 71283) did not meet the definition of critical habitat and was not proposed for revised designation. Subunit 5b: Devil Canyon Subunit 5b consists of 266 ac (108 ha) of Federal land (CNF) and 8 ac (3 ha) of private land in northern San Diego County. Hybrids between Brodiaea filifolia and B. orcuttii have been reported from the Devil Canyon site, however, we believe B. filifolia occurs in sufficient numbers in this area to meet the criteria for critical habitat designation ( see the Special Management Considerations or Protection section of this rule for a discussion of Brodiaea hybridization). 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 CNF does not currently have a management plan specific to B. filifolia. The 2005 critical habitat rule for B. filifolia and the 2009 proposed revised critical habitat rule erroneously stated that grazing occurs in this area; this area is in fact not subjected to cattle grazing (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 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, California, and consists of five subunits totaling 230 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 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 and pollinator habitat (PCE 2); and (2) supports a stable, persistent occurrence of at least 1,500 individuals of B. filifolia (Affinis 2005, pp. 1-3; AMEC 2005 pp. 3-18). 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 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 of at least 1,500 individuals of B. filifolia (Roberts 2005a, pp.1-2). 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 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 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 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 and pollinator habitat (PCE 2); and (2) supports a stable, persistent occurrence of at least 1,300 individuals of B. filifolia (Roberts 2005b, 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 rule for a discussion of the threats to 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 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 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 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; and (3) consists primarily of annual and needlegrass grassland and occurs in the largest continuous block of grassland habitat remaining in the 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 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, California, and consists of three subunits totaling 105 ac (43 ha). This unit contains 1 ac (<1 ha) of State land and 104 ac (43 ha) of private land. These totals do not include Subunit 7d (98 ac (40 ha)) and portions of Subunit 7a (13 ac (5 ha)) and Subunit 7c (45 ac (18 ha)) that we are exercising our delegated discretion to exclude from this revised designation under section 4(b)(2) of the Act ( see the Exclusions under Section 4(b)(2) of the Act section of this rule), or 2 ac (<1 ha) that were proposed as revised critical habitat but are not included in this final revised critical habitat designation because they do not support suitable habitat for the species. Subunit 7a: Letterbox Canyon Subunit 7a consists of 1 ac (<1 ha) of State land and 41 ac (17 ha) of private land in the City of Carlsbad, in northern coastal San Diego County, California. 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 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 39,500 individuals of B. filifolia, as documented in 2005 (CNDDB 2009, p. 15). 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 rule for a discussion of the threats to B. filifolia habitat and potential management considerations. 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, California. This subunit was not included in the 2005 final critical habitat designation, but is included in this 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 rule for a discussion of the threats to B. filifolia habitat and potential management considerations. Subunit 7c: Calavera Hills Village H Subunit 7c consists of 26 ac (11 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 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 rule for a discussion of the threats to B. filifolia habitat and potential management considerations. Unit 8: San Marcos, San Diego County Unit 8 is located in San Marcos, northern San Diego County, California, and consists of three subunits totaling 108 ac (44 ha) of private land. Subunits 8a, 8c, and 8e as proposed in the December 8, 2004, rule (69 FR 71283) did not meet the definition of critical habitat and were not proposed for revised designation. 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, California. This subunit was not included in the 2005 final critical habitat designation, but is included in this 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 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. Hybrids between Brodiaea filifolia and B. orcuttii have been reported from the Upham site (Chester et al. 2007, p. 188), however, based on the best scientific information available to us at this time, we believe B. filifolia occurs in sufficient numbers in this area to meet the criteria for critical habitat designation ( see the Special Management Considerations or Protection section of this rule for a discussion of Brodiaea hybridization). 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 rule for a discussion of the threats to B. filifolia habitat and potential management considerations. Subunit 8f: Oleander/San Marcos Elementary 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 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 3,211 individuals of B. filifolia, as documented in 2005 (Dudek and Associates, Inc. 2007, 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 nonnative invasive plants. Please see the Special Management Considerations or Protection section of this 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, California, and consists of 6 subunits totaling 1,113 ac (450 ha). This unit contains 53 ac (21 ha) of Federal land, 366 ac (148 ha) of State land, 33 ac (13 ha) of local government land, and 661 ac (267 ha) of private land. These totals do not include Subunits 11g (117 ac (47 ha)), 11h (44 ac (18 ha)) and portions of Subunit 11f (221 ac (89 ha)) that we are exercising our delegated discretion to exclude from this revised designation under section 4(b)(2) of the Act ( see the Exclusions under Section 4(b)(2) of the Act section of this rule). Subunit 11a: San Jacinto Wildlife Area Subunit 11a consists of 366 ac (148 ha) of State land (California Department of Fish and Game (CDFG)), 17 ac (7 ha) of local government land, and 18 ac (7 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 2004b, pp. 137-189). Please see the Special Management Considerations or Protection section of this rule for a discussion of the threats to B. filifolia habitat and potential management considerations. Subunit 11b: San Jacinto Avenue/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, 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 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 rule for a discussion of the threats to B. filifolia habitat and potential management considerations. Subunit 11c: Case Road Subunit 11c consists of 11 ac (4 ha) of local government land and 169 ac (68 ha) of private land 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, 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 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 rule for a discussion of the threats to B. filifolia habitat and potential management considerations. Subunit 11d: Railroad Canyon Subunit 11d consists of 53 ac (21 ha) of Federal land owned by the Bureau of Land Management, 1 ac (<1 ha) of local government land, and 204 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, 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 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 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 rule for a discussion of the threats to B. filifolia habitat and potential management considerations. Subunit 11e: Upper Salt Creek (Stowe Pool) Subunit 11e consists of 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 (such as Hordeum marinum subsp. gussoneanum ) and transportation projects. Please see the Special Management Considerations or Protection section of this rule for a discussion of the threats to B. filifolia habitat and potential management considerations. Subunit 11f: Santa Rosa Plateau—Mesa de Colorado Subunit 11f consists of 5 ac (2 ha) of local government land and 8 ac (3 ha) of private land 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 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 31,725 individuals of 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 rule for a discussion of the threa [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2011-2403. Public record. Not legal advice.