Endangered and Threatened Wildlife and Plants; Revised Endangered Status, Revised Critical Habitat Designation, and Taxonomic Revision for Monardella linoides
We, the U.S. Fish and Wildlife Service (Service), recognize the recent change to the taxonomy of the currently endangered plant taxon, Monardella linoides ssp. viminea, in which the subspecies was split into two distinct full species, Monardella viminea (willowy monardella) and Monardella stoneana (Jennifer's monardella). Because the original subspecies, Monardella linoides ssp. viminea, was listed as endangered under the Endangered Species Act of 1973, as amended (Act), we reviewed and updated the threats analysis that we completed for the taxon in 1998, when it was listed as a subspecies. We also reviewed the status of the new species, Monardella stoneana. We retain the listing status of Monardella viminea as endangered, and we remove protections afforded by the Act from those individuals now recognized as the separate species, Monardella stoneana, because the new species does not meet the definition of endangered or threatened under the Act. We also revise designated critical habitat for Monardella viminea. In total, approximately 122 acres (50 hectares) in San Diego County, California, fall within the boundaries of the critical habitat designation. We are not designating critical habitat for Monardella stoneana because this species does not warrant listing under the Act.
Endangered and Threatened Wildlife and Plants; Redesignation of Critical Habitat for the Willowy Monardella
5 actions from June 9th, 2011 to February 2012
June 9th, 2011
August 8th, 2011
- NPRM Comment Period End
September 28th, 2011
- NPRM Comment Period Reopened
October 28th, 2011
- NPRM Comment Period Reopened End
- Final Action
Table of Contents Back to Top
- FOR FURTHER INFORMATION CONTACT:
- SUPPLEMENTARY INFORMATION:
- Procedural Aspects of This Rule
- New Information on Occurrences of Monardella viminea and Monardella stoneana
- Summary of Changes From Proposed Rule
- Previous Federal Actions
- Summary of Factors Affecting Monardella viminea
- A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range
- Sand and Gravel Mining
- Altered Hydrology
- Fire and Type Conversion
- Summary of Factor A
- B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes
- C. Disease or Predation
- D. The Inadequacy of Existing Regulatory Mechanisms
- Federal Protections
- National Environmental Policy Act (NEPA)
- Sikes Act
- Clean Water Act (CWA)
- State and Local Regulations
- California's Native Plant Protection Act (NPPA) and Endangered Species Act (CESA)
- California Environmental Quality Act (CEQA)
- California's Natural Community Conservation Planning (NCCP) Act
- City of San Diego and County of San Diego Subarea Plans Under the Multiple Species Conservation Plan (MSCP)
- Summary of Factor D
- E. Other Natural or Manmade Factors Affecting Its Continued Existence
- Nonnative Plant Species
- Small Population Size and Restricted Range
- Climate Change
- Summary of Factor E
- Cumulative Impacts
- Significant Portion of Range
- Summary of Factors Affecting Monardella stoneana
- A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range
- Sand and Gravel Mining
- Altered Hydrology
- Fire and Type Conversion
- Summary of Factor A
- B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes
- C. Disease or Predation
- D. The Inadequacy of Existing Regulatory Mechanisms
- Federal Regulations
- National Environmental Policy Act (NEPA)
- Clean Water Act (CWA)
- Wilderness Act and Federal Land Policy and Management Act
- State and Local Regulations
- Native Plant Protection Act (NPPA) and California Endangered Species Act (CESA)
- California Environmental Quality Act (CEQA)
- Otay Mountain Ecological Reserve
- The Natural Community Conservation Planning (NCCP) Act
- City and County of San Diego Subarea Plans Under the Multiple Species Conservation Plan (MSCP)
- Summary of Factor D
- E. Other Natural or Manmade Factors Affecting Its Continued Existence
- Nonnative Plant Species
- Small Population Size
- Climate Change
- Summary of Factor E
- Cumulative Impacts
- Significant Portion of Range
- Critical Habitat
- Physical or Biological Features
- Space for Individual and Population Growth and for Normal Behavior
- Food, Water, Air, Light, Minerals, or Other Nutritional or Physiological Requirements
- Cover or Shelter
- Sites for Breeding, Reproduction, and Rearing (or Development) of Offspring
- Habitats Protected From Disturbance or Representative of the Historical, Geographical, and Ecological Distributions of the Species
- Primary Constituent Elements for Monardella viminea
- Special Management Considerations or Protection
- Criteria Used To Identify Critical Habitat
- Final Critical Habitat Designation
- Unit 1: Sycamore Canyon
- Unit 2: West Sycamore Canyon
- Effects of Critical Habitat Designation
- Section 7 Consultation
- Application of the “Adverse Modification” Standard
- Application of Section 4(a)(3) of the Act
- Marine Corps Air Station Miramar (MCAS Miramar)
- Application of Section 4(b)(2) of the Act
- Exclusions Based on Economic Impacts
- Exclusions Based on National Security Impacts
- Exclusions Based on Other Relevant Impacts
- Land and Resource Management Plans, Conservation Plans, or Agreements Based on Conservation Partnerships
- Benefits of Inclusion—City of San Diego Subarea Plan and the County of San Diego Subarea Plan Under the San Diego MSCP
- Benefits of Exclusion—City of San Diego Subarea Plan and the County of San Diego Subarea Plan Under the San Diego MSCP
- The Benefits of Exclusion Outweigh the Benefits of Inclusion—City of San Diego Subarea Plan and the County of San Diego Subarea Plan Under the San Diego MSCP
- Exclusion Will Not Result in Extinction of the Species—City of San Diego Subarea Plan and the County of San Diego Subarea Plan Under the San Diego MSCP
- Summary of Comments and Recommendations
- Peer Review
- Peer Reviewer Comments
- Comments About Monardella viminea
- Comments About Monardella stoneana
- Comments About Critical Habitat
- Comments From Federal Agencies
- Comments From Local Agencies
- Public Comments
- Comments Regarding the Taxonomic Split of Monardella linoides ssp. viminea
- Comments Regarding Monardella viminea
- Comments Regarding Monardella stoneana
- Critical Habitat for Monardella viminea
- Required Determinations
- Regulatory Planning and Review—Executive Order 12866
- Regulatory Flexibility Act (5 U.S.C. 601 et seq.)
- Small Business Regulatory Enforcement Fairness Act (5 U.S.C 801 et seq.)
- Energy Supply, Distribution, or Use—Executive Order 13211
- Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.)
- Takings—Executive Order 12630
- Federalism—Executive Order 13132
- Civil Justice Reform—Executive Order 12988
- Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)
- National Environmental Policy Act (42 U.S.C. 4321 et seq.)
- Government-to-Government Relationship With Tribes
- References Cited
- List of Subjects in 50 CFR Part 17
- Regulation Promulgation
- PART 17—[AMENDED]
- Family Lamiaceae: Monardella viminea (willowy monardella)
Tables Back to Top
- Table 1—List of Element Occurrences of Monardella viminea and Monardella stoneana by Location, and When Those Occurrences Were Known To Be Extant
- Table 2—Changes in Ownership Area Totals Between Proposed and Final Rules
- Table 3—Comparison of the 2006 Final Critical Habitat Designation for Monardella linoides ssp. Viminea, the 2011 Proposed Critical Habitat Designation for M. viminea, and the 2012 Final Critical Habitat Designation for M. viminea
- Table 4—Critical Habitat Units for Monardella viminea, Showing Estimated Area in Acres (Hectares), Land Ownership, Areas Excluded Under Section 4(b)(2) of the Act, and Areas Exempt Under Section 4(a)(3)(B)(i) of the Act
- Table 5—Areas Excluded Under Section 4(b)(2) of the Act From This Final Critical Habitat Designation for Monardella Viminea
DATES: Back to Top
This rule becomes effective on April 5, 2012.
ADDRESSES: Back to Top
This final rule and the associated final economic analysis are available on the Internet at http://www.regulations.gov. Comments and materials received, as well as supporting documentation used in preparing this final rule, are 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: Back to Top
Jim Bartel, Field Supervisor, U.S. Fish and Wildlife Service, Carlsbad Fish and Wildlife Office, 6010 Hidden Valley Road, Suite 101, Carlsbad, CA 92011; telephone 760-431-9440; facsimile 760-431-5901. If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION: Back to Top
Background Back to Top
It is our intent to discuss only those topics directly relevant to our recognition of the taxonomic split of Monardella linoides ssp. viminea into two distinct taxa: Monardella viminea (willowy monardella) and Monardella stoneana (Jennifer's monardella), the retention of M. viminea as endangered, the designation of critical habitat for M. viminea under the Act (16 U.S.C. 1531 et seq.), and our conclusion that M. stoneana does not meet the definition of endangered or threatened under the Act. For more information on the biology and ecology of M. viminea and M. stoneana, refer to the final listing rule published in the Federal Register on October 13, 1998 (63 FR 54938) and the critical habitat rule published November 8, 2006 (71 FR 65662). For new information specific to M. viminea and M. stoneana, including species descriptions, distributions, taxonomic ranks, and nomenclature, as well as new information on soils, potential pollinators, and current threats to the two species not included in our original listing or critical habitat rules for M. linoides ssp. viminea, refer to the proposed rule to designate revised critical habitat for M. viminea published in the Federal Register on June 9, 2011 (76 FR 33880). For information on the associated draft economic analysis for the proposed rule to designate revised critical habitat, refer to the document published in the Federal Register on September 28, 2011 (76 FR 59990).
Procedural Aspects of This Rule
In 2003, Elvin and Sanders proposed a taxonomic split of the previously listed entity Monardella linoides ssp. viminea into two distinct species. The Service initially disagreed with the segregation and classification of M. stoneana as a distinct species due to lack of sufficient supportive evidence presented by Elvin and Sanders (Bartel and Wallace 2004, pp. 1-3), but upon review of corroborating genetic analysis by Prince (2009), we accept the treatment of Elvin and Sanders (2003). This treatment found that some discrete occurrences that were previously identified as the listed entity Monardella linoides ssp. viminea do not in fact represent that entity, but rather a separate taxon. We also accept, and will use here, the scientific name Monardella viminea for the listed willowy monardella. Elvin and Sanders (2003, p. 426) provided the name Monardella stoneana for plants they determined were sufficiently distinct from willowy monardella to warrant recognition at the species rank. These authors returned willowy monardella to species status as M. viminea, the name under which it was originally described. In addition, Elvin and Sanders (2003, p. 431) point out its distinctiveness from M. linoides taxa in San Diego County, California.
Several consequences result from the change in taxonomy and recognition of the species split. First, we will refer to willowy monardella as Monardella viminea. Second, the range, description, and the magnitude and immediacy of threats to the listed entity (now M. viminea) have changed. A map of the distributions of the two species, M. viminea and M. stoneana, is provided in Figure 1, below. Third, those individuals now recognized as M. stoneana, which are identified as morphologically and ecologically distinct from the listed entity (M. viminea), are no longer afforded protections by the Act under the name M. viminea.
In this final rule, we present the results of a status review for Monardella viminea in consideration of its changed morphological and ecological description and diminished range. We also present our revised designation of critical habitat for M. viminea. Finally, we present the results of our status review for those plants previously protected under the Act as M. viminea, and that are now identified as M. stoneana, and conclude M. stoneana does not meet the definition of endangered or threatened under the Act.
We first proposed recognizing the taxonomic classification of Monardella linoides ssp. viminea as a distinct species (M. viminea) and reclassifying a portion of Monardella linoides ssp. viminea as a separate species (M. stoneana) in the proposed listing and revised critical habitat rule published in the Federal Register on June 9, 2011 (76 FR 33880). Based on the information presented in the proposed rule (see Taxonomic and Nomenclatural Changes Affecting Monardella linoides ssp. viminea of the proposed rule (76 FR 33880, June 9, 2011)), and acceptance by the scientific community, we finalize the taxonomic change and amend the List of Endangered and Threatened Plants at 50 Code of Federal Regulations (CFR) 17.12(h) to identify the listed entity as “Monardella viminea (willowy monardella).”
BILLING CODE 4310-55-P
BILLING CODE 4310-55-C
New Information on Occurrences of Monardella viminea and Monardella stoneana
In this document we use the word “occurrence” when describing the location of Monardella viminea plants. In this context, we are referring to point locations that contain one or more M. viminea individuals or to polygons representing the boundaries of clumps of plants. These point locations or polygons may include one or more of the “element occurrences” (EOs) as described by the California Department of Fish and Game (CDFG) in the California Natural Diversity Database (CNDDB). Utilizing EOs to describe locations of M. viminea plants in our listing and critical habitat analyses is consistent with terminology used by the Service in previous rules for this species. It also provides clarity in referencing clumps of plants in canyons that may be referred to by multiple or changing names. In all other respects in this document, “element occurrence” or “occurrence” references are those from the cumulative data of the CNDDB (2011a, EOs 1-31).
As discussed in the June 9, 2011, proposed rule (76 FR 33880), when we listed Monardella linoides ssp. viminea, we considered 20 occurrences to be extant in the United States (see Table 1) (63 FR 54938, October 13, 1998). As of 2008, 9 occurrences were considered extirpated, leaving 11 extant occurrences (Service 2008, p. 5). All nine extirpated occurrences were in central San Diego County in the range of what is now considered to be M. viminea. Based on updated information from Marine Corps Air Station (MCAS) Miramar (Kassebaum 2010, pers. comm.), 2 additional occurrences of those 11 extant occurrences have since been extirpated, again in the range of M. viminea. Additionally, as a result of taxonomic changes, the two southernmost element occurrences previously considered M. linoides ssp. viminea were reclassified as M. stoneana after the 2008 5-year review, leaving seven extant occurrences of M. viminea (see Table 1). We now consider an eighth occurrence to be extant, as described in the following paragraphs.
|Location||CNDDB Element Occurrence No. (EO)||Known and extant at listing||Extant at 2008 5-yr review||Currently extant|
|Sources: CNDDB 1998, 2007, 2011a, 2011b; Service 2008, Table 1; Kassebaum 2010, pers. comm.|
|San Clemente Canyon||11||X|
|San Clemente Canyon||12||X||X|
|San Clemente Canyon||13||X|
|San Clemente Canyon||16||X|
|San Clemente Canyon||17||X|
|West Sycamore Canyon||21||X||X||X|
|San Clemente Canyon||27||X||X||X|
|Otay Lakes||28||X||X||Now considered M. stoneana EO4|
|Marron Valley||none||X||X||Now considered M. stoneana EO1|
|NW Otay Mountain||2||X||X|
|NW Otay Mountain||3||X||X|
|S. of Otay Mountain||8||X||X|
After a new review of Geographical Information Systems (GIS) data and the most recent survey report from MCAS Miramar, we found that an occurrence of M. viminea in San Clemente Canyon had incorrectly been reported as extirpated both in the 2008 5-year review and the June 9, 2011, proposed rule. Further reviews of data from MCAS Miramar showed that plants have continuously been present in the location that was incorrectly considered extirpated (Rebman and Dossey 2006, Map 10; Tierra Data 2011, Map 6). Therefore, we now recognize EO 12 as extant. We believe there are now eight element occurrences of M. viminea, and that these eight EOs were extant at the time of listing. Therefore, we currently consider only 10 occurrences to be extirpated rather than 11. We are not aware of any new occurrences of M. viminea, other than those planted in 2007, as a conservation measure to offset impacts associated with the development of the Carroll Canyon Business Park. More information on four translocated occurrences is discussed in the Geographic Range and Status section in the proposed rule (76 FR 33880, June 9, 2011).
In addition to two occurrences now considered to be Monardella stoneana (but considered at listing to be M. linoides ssp. viminea), we now know of an additional seven occurrences of M. stoneana, all in what was once the southern range of M. linoides ssp. viminea (Figure 1, above). We presume those occurrences were extant at the time M. linoides ssp. viminea was listed. Although we reported in the June 9, 2011, proposed rule that the single plant in the M. stoneana occurrence at Otay Lakes (M. stoneana EO 4, formerly M. viminea EO 28) was extirpated by the 2007 Harris Fire, 2011 surveys by the City of San Diego reported a single plant had resprouted in the same location (City of San Diego 2011a, p. 229). The monitor for the city reported that the plant was of robust size and height, making it more likely to be a resprout than a juvenile or seedling (Miller 2011, pers. comm.). Therefore, in this final rule, we now consider nine occurrences of M. stoneana to be extant.
Throughout this document we refer to previous reports and documents, including Federal Register publications. Information contained in documents issued prior to the present document may reference Monardella viminea as M. linoides ssp. viminea, and may include statements or data referring to plants or populations now known as M. stoneana.
Summary of Changes From Proposed Rule Back to Top
In preparing this final listing rule and critical habitat designation, we reviewed and considered comments from the public on the proposed listing of Monardella viminea, proposed removal of plants now recognized as M. stoneana from the listed entity, and proposed designation of critical habitat for M. viminea published on June 9, 2011 (76 FR 33880). As a result of public comments and peer review, we made slight changes to our analysis of threats for both species and the revised designation of critical habitat for M. viminea. These changes are as follows:
(1) We added information from a Monardella viminea habitat study conducted by researchers at MCAS Miramar. The study examined three different treatments for enhancing habitat conditions for M. viminea: hand removal of nonnative grasses, herbicide application to nonnative grasses, and application of cobble to provide rock mulch (AMEC 2011, p. 1-1). We also added findings from the study to the Factor A and Factor C analyses for M. viminea, and to the Special Management Considerations or Protection section. Additionally, we added information on habitat fragmentation to the Factor A analysis for M. viminea.
(2) Based on information submitted by commenters, we added information to the five-factor analyses for both species, such as the effects of trampling on Monardella viminea, the effects of road construction on M. stoneana, and factors influencing the lack of recruitment for M. viminea.
(3) Based on a suggestion we received from a commenter, we added a discussion of protections afforded by the Clean Water Act (33 U.S.C. 1251 et seq.) to the five-factor analyses for both species.
(4) Based on information presented by a commenter, we revised the list of activities requiring consultation for critical habitat, including removal of activities that have previously had no detrimental effect on Monardella viminea (such as fire retardant use). We also removed mention of herbicide application as an activity that requires consultation because small-scale application of herbicide on weeds in direct proximity to M. viminea has a demonstrated benefit to the species.
(5) We updated this final rule to include information about protections afforded to Monardella viminea by the newly approved integrated natural resources management plan (INRMP) for MCAS Miramar.
(6) Based on information submitted by commenters, we updated the Special Management Considerations or Protection section with measures on how to manage and protect essential habitat that supports Monardella viminea.
(7) Based on further communication with managers of Otay Mountain Ecological Reserve, we updated the management policies and guidelines for the Reserve in the Factor D discussion for Monardella stoneana.
(8) We added further information on possible threats posed by illegal border crossings to Factor A for Monardella stoneana.
(9) As requested by a commenter, we revised the Altered Hydrology section in the Factor A analysis for Monardella viminea to address changing watershed conditions in the range of the species.
(10) The areas designated as critical habitat in this final rule constitute a slight revision of the critical habitat for Monardella viminea we proposed on June 9, 2011 (76 FR 33880). During the first public comment period, we received notification from MCAS Miramar that we were not using the most recent boundaries in the proposed rule (Dept. of Environmental Management, MCAS Miramar 2011, p. 3). While there was no change in the total area identified as critical habitat, ownership area totals in some areas did change, as shown in Table 2.
|Proposed critical habitat||Final critical habitat|
|Federal ac (ha)||State/local ac (ha)||Private ac (ha)||Federal ac (ha)||State/local ac (ha)||Private ac (ha)|
|Values in this table may not sum due to rounding.|
|* “Proposed designation” includes acreages proposed for exclusion.|
|** Excluded acreages include private lands covered by the City of San Diego and County of San Diego Subarea Plans under the San Diego Multiple Species Conservation Program (MSCP).|
|Unit 1—Sycamore Canyon||156 (63)||25 (10)||170 (69)||153 (62)||22 (8)||175 (70)|
|Unit 2—West Sycamore Canyon||550 (222)||27 (11)||0 (0)||551 (223)||26 (11)||0 (0)|
|Unit 3—Spring Canyon||176 (71)||5 (2)||92 (37)||170 (69)||5 (2)||98 (40)|
|Unit 4—East San Clemente Canyon||454 (184)||13 (5)||0 (0)||462 (187)||5 (2)||0 (0)|
|Unit 5—West San Clemente Canyon||210 (85)||16 (7)||1 (<1)||227 (92)||0 (0)||0 (0)|
|Total||1,546 (626)||86 (35)||263 (106)||1,563 (663)||58 (24)||273 (111)|
|Total Essential Habitat||1,895 (767)||1,895 (767)|
|Exempted||Proposed excluded||Proposed designation *||Exempted||Excluded **||Designated|
|1,546 (626)||208 (84)||348 (141)||1,563 (663)||210 (85)||122 (50)|
(11) Table 3 of the proposed rule incorrectly listed Unit 1 as consisting of 158 ac (64 ha) of private land and 36 ac (15 ha) of state and local land. The table should have shown 170 ac (69 ha) of private land and 25 ac (10 ha) of state and local land.
(12) In the June 9, 2011, proposed revised rule, we stated that we were considering lands owned by or under the jurisdiction of the City of San Diego Subarea Plan and the County of San Diego Subarea Plan under the San Diego Multiple Species Conservation Program (MSCP) for exclusion under section 4(b)(2) of the Act. We have now made a final determination that the benefits of exclusion outweigh the benefits of inclusion of lands covered by the City and County Subarea Plans and that exclusion of these lands will not result in extinction of the species. Therefore, the Secretary is exercising his discretion to exclude approximately 177 acres (ac) (72 hectares (ha)) of land within the boundaries of the City of San Diego Subarea Plan and 32 ac (13 ha) within the County of San Diego Subarea Plan from this final designation. For a complete discussion of the benefits of inclusion and exclusion, see the Exclusions section below.
Only information relevant to actions described in this final rule is provided below. For additional information on Monardella viminea, including a detailed description of its life history and habitat, refer to the final listing rule published in the Federal Register on October 13, 1998 (63 FR 54938), the final rule designating critical habitat published in the Federal Register on November 8, 2006 (71 FR 65662), the 5-year review completed in March 2008 (Service 2008), and the proposed rule published on June 9, 2011 (76 FR 33880). Actions described below include status reviews of M. viminea and M. stoneana and a revision of the critical habitat designation for M. viminea.
Previous Federal Actions
Monardella linoides ssp. viminea was listed as endangered in 1998 (63 FR 54938, October 13, 1998). An account of Federal actions prior to listing may be found in the listing rule (63 FR 54938, October 13, 1998). On November 9, 2005, we published a proposed rule to designate critical habitat for M. linoides ssp. viminea (70 FR 67956). On November 8, 2006 (71 FR 65662), we published our final rule designating critical habitat for M. linoides ssp. viminea. On January 14, 2009, the Center for Biological Diversity filed a complaint in the U.S. District Court for the Southern District of California challenging our designation of critical habitat for M. linoides ssp. viminea (Center for Biological Diversity v. United States Fish and Wildlife Service and Dirk Kempthorne, Secretary of the Interior, Case No. 3:09-CV-0050-MMA-AJB). A settlement agreement was reached with the plaintiffs dated November 14, 2009, in which we agreed to submit a proposed revised critical habitat designation to the Federal Register for publication by February 18, 2011, and a final revised critical habitat designation to the Federal Register for publication by February 17, 2012. By order dated February 10, 2011, the district court approved a modification to the settlement agreement that extended the deadline for Federal Register submission to June 18, 2011, for the proposed revised critical habitat designation; we published the proposed rule in the Federal Register on June 9, 2011 (76 FR 33880). The deadline for submission of a final revised critical habitat designation to the Federal Register remains February 17, 2012. This rule complies with the conditions of the settlement agreement.
Summary of Factors Affecting Monardella viminea Back to Top
Section 4 of the Act and its implementing regulations (50 CFR part 424) set forth the procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. A species may be determined to be an endangered or threatened species due to one or more of the five factors described in section 4(a)(1) of the Act: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. Listing actions may be warranted based on any of the above threat factors, singly or in combination. Each of these factors for Monardella viminea is discussed below.
A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range
The original listing rule identified urban and residential development as a threat to Monardella linoides ssp . viminea (63 FR 54938, October 13, 1998). Prior to 1992, San Diego had grown by “a factor of 10 over the last 50 years” (Soule et al. 1992, p. 39). At the time of listing, two large occurrences were located on private property, and development proposals existed for one of the parcels. Since listing, one of those two occurrences, EO 25 from the Carroll Canyon Business Park (CNDDB 2011a), has been extirpated due to construction activities. Additionally, EO 14 in Murphy Canyon was believed extirpated after listing due to lingering impacts from construction activity near Highway 15 (CNDDB 2011a).
The Cities of San Diego and Santee have purchased private property as reserve land for Monardella viminea. Most occurrences are now found on land conserved or owned by MCAS Miramar, the City of San Diego, and the County of San Diego. Lands owned by the City and County of San Diego are covered by the MSCP, which is a habitat conservation plan (HCP) intended to maintain and enhance biological diversity in the San Diego region, and to conserve viable populations of endangered, threatened, and key sensitive species and their habitats (including M. viminea). The MSCP designates lands to be set aside for biological preserves. However, 10 percent of habitat for M. viminea occurs on privately owned land outside of the reserve areas. This land includes areas in the City of Santee outside of the purchased reserve land, and one of the four transplanted occurrences in Carroll Canyon within the boundaries of the City of San Diego (Ince and Krantz 2008, p. 1). Any sites outside of the MSCP reserve areas are vulnerable to development. Portions of Sycamore Canyon where M. viminea occurs were previously slated for development (Service 2003a, pp. 1-23), although the project has been put on hold due to bankruptcy issues, and no development is currently scheduled (San Diego Business Journal 2011, pp. 1-3).
Another potential impact of increased urbanization is habitat fragmentation. As noted in the New Information on Occurrences of Monardella viminea and Monardella stoneana section above, 11 occurrences of Monardella viminea have been extirpated since listing. To some extent, M. viminea evolved in a naturally fragmented landscape, as it occurs in individual drainages. In natural conditions, some habitat connectivity could be provided through pollinator movement between occurrences in close proximity to each other. Uninterrupted habitat within canyons is also important for maintaining the downstream flows that create secondary benches and sandbars upon which M. viminea grows, and for scouring nonnative grasses from those areas. Thus, under unaltered conditions, habitat fragmentation is not a threat to M. viminea. However, urbanization (particularly in areas surrounding occurrences of M. viminea in Carroll and Lopez Canyons) interrupts pollinator movement and natural streamflow in the canyons, and urbanization could prevent movement and decrease genetic diversity of the species. Additionally, in San Clemente Canyon, the Sim J. Harris aggregate mine acts as a barrier to the physical and biotic continuity, and as a barrier to natural water flow between the east and west halves of the canyon, although natural habitat for pollinators remains.
The occurrences discussed above represent only a small proportion of habitat that contains clumps of Monardella viminea. Seventy percent of land where M. viminea occurs is owned and managed by MCAS Miramar, and most remaining large occurrences (with more than 100 clumps of M. viminea) are found on MCAS Miramar, with the exception of Spring Canyon (CNPS 2011, p. 7). All M. viminea on MCAS Miramar occurs within Level I or II management areas (see Exemptions below for explanation of the two levels of management). Management areas on MCAS Miramar provide a guide for mitigation actions for development on the base, and are organized based “on differing resource conservation requirements and management concerns” (Gene Stout and Associates et al. 2011, p. 5-2). Level I and II management areas are those that contain sensitive species. Specific mitigation measures within Level I and II management areas depend on the surrounding habitat type. For temporary habitat loss in riparian corridors, all actions must include measures to minimize direct impact to the habitat, decrease erosion and runoff, and provide for a 2:1 ratio of habitat enhancement and restoration for endangered and threatened plants. For permanent habitat loss within riparian areas where listed species are present, the following actions occur: Creation of a corridor for wildlife movement of 500 feet (ft) (150 meters (m)) or less, assurance of no net loss of wetland habitat, and suitable compensation for occupied habitat at a 2:1 ratio (Gene Stout and Associates et al. 2011, Tables 18.104.22.168a, 22.214.171.124b). Therefore, although urbanization does threaten some occurrences of Monardella viminea, and effects from habitat fragmentation may occur on the edge of the species' range, the threat to the species' habitat is not significant across the range of the species.
Sand and Gravel Mining
Sand and gravel mining was identified at the time of listing as adversely affecting Monardella linoides ssp. viminea (63 FR 54938, October 13, 1998). Sand and gravel mining has broad-scale disruptive qualities to native ecosystems (Kondolf et al. 2002, p. 56). The larger (340 individuals) of two occurrences found on private land at the time of listing was identified as being threatened by sand and gravel mining, which had the potential to eliminate or disrupt these local populations through changes in hydrology and elimination of individual plants. Since listing, all occurrences vulnerable to mining impacts have been extirpated, either by altered drainage patterns or construction unrelated to mining operations (CNDDB 2011a, EOs 3 and 25). Currently, we are not aware of any ongoing mining activities or plans for future mining activities that would impact the species. While we may not be fully aware of all potential gravel mining activities on private lands, few M. viminea occurrences are on private land. Therefore, we do not consider sand and gravel mining to be a threat to M. viminea now or in the future.
The original listing rule identified altered hydrology as a threat to Monardella linoides ssp . viminea, particularly in those portions of the habitat now considered to be in the range of M. viminea (63 FR 54938, October 13, 1998). Monardella viminea requires a natural hydrological system to maintain and deposit material for the secondary benches and streambeds on which the species grows (Scheid 1985, pp. 30-31, 34-35). Upstream development can disrupt this regime, increasing storm runoff that can erode, rather than establish, the sandy banks and secondary benches upon which M. viminea grows. White and Greer (2006, p. 131) found that streamflow conditions in the Los Peñasquitos Creek system, which includes M. viminea occurrences in Carroll and Lopez Canyons, have changed drastically from historical conditions. Their study estimated that urbanization of the area increased from 9 percent in 1973, to 37 percent in 2000, and that, correspondingly, runoff in the canyons increased by 200 percent over that same period (White and Greer 2006, p. 134). Further, strong floods within the watershed have increased from 350 to 700 percent over the same time period, with no corresponding increase in rainfall (White and Greer 2006, pp. 134-135). Such watershed changes can alter the riparian vegetation community through changes in median and minimum daily discharges, dry season runoff, and flood magnitudes (White and Greer 2006, pp. 133-136). Increased strong floods also have the potential to wash away plants as large as or larger than M. viminea, as has occurred in Lopez Canyon during heavy runoff following winter storms (Kelly and Burrascano 2001, pp. 2-3), where flooding severely impacted the M. viminea occurrences (Kelly and Burrascano 2006, pp. 65-69).
Additionally, increases in surface and subsurface soil moisture (via direct effects to the water table associated with watershed urbanization), and changes in streamflow from ephemeral to perennial, adversely affect native plants, such as Monardella viminea, that are adapted to a drier Mediterranean climate (cool moist winters and hot dry summers). Monardella viminea has been unable to adapt to the increased soil moisture and nonnative species incursion has been exacerbated by the changing water regime (underground hydrology) (Burrascano 2007, pers. comm.). Nonnative species can smother seedling and mature plants and prevent natural growth of M. viminea (Rebman and Dossey 2006, p. 12).
Since listing, three occurrences have been extirpated due to altered hydrological patterns: Cemetery Canyon, Carroll Canyon, and western San Clemente Canyon (CNDDB 2011a, EOs 3, 4, 11). All three of these occurrences are on city-owned or private land. On MCAS Miramar, watersheds on the undeveloped eastern half of the base, where over 80 percent of Monardella viminea plants are found, appear to have retained their natural hydrological regime (Rebman and Dossey 2006, p. 37).
Considering the synergistic and cumulative effects of these combined hydrological threats exacerbated by heavy development surrounding several canyons, we expect that altered hydrology will continue to pose a significant threat to habitats that support Monardella viminea, particularly outside the border of MCAS Miramar. We anticipate that this threat will continue into the future.
Fire and Type Conversion
The listing rule mentioned that fuel modification to exclude fire could affect Monardella linoides ssp . viminea (63 FR 54938, October 13, 1998); the same is true of the reclassified M. viminea and its habitat. Otherwise, fire was not considered a severe threat to the species at the time of listing.
Our understanding of fire in fire-dependent habitats has changed since Monardella linoides ssp . viminea was listed in 1998 (Dyer 2002, pp. 295-296). Fire is a natural component for regeneration and maintenance of M. viminea habitat. The species' habitat needs concerning fire seem contradictory; a total lack of fire for long periods is undesirable, because the fires that eventually occur can be catastrophic, yet re-introduction of fire (either accidentally or purposefully) is also undesirable, because such fire often becomes catastrophic (megafire) as a result of high fuel loads due to previous lack of fire. This paradox has resulted from a disruption of the natural fire regime.
Fire frequency has increased in North American Mediterranean shrublands since about the 1950s, and studies indicate that southern California has the greatest increase in wildfire ignitions, primarily due to an increase in population density beginning in the 1960s, thus increasing the number of human-caused fires (Keeley and Fotheringham 2003, p. 240). Increased wildfire frequency and decreased fire return interval, in conjunction with other effects of urbanization, such as increased nitrogen deposition and habitat disturbance due to foot and vehicle traffic, are believed to have resulted in the conversion of large areas of coastal sage scrub to nonnative grasslands in southern California (Service 2003b, pp. 57-62; Brooks et al. 2004, p. 677; Keeley et al. 2005, p. 2109; Marschalek and Klein 2010, p. 8). This type conversion (conversion of one type of habitat to another) produces a positive feedback mechanism resulting in more frequent fires and increasing nonnative plant cover (Brooks et al. 2004, p. 677; Keeley et al. 2005, p. 2109).
Threats to the habitat from fire exclusion, which impact processes that historically created and maintained suitable habitat for Monardella viminea, may make the species even more vulnerable to extinction. The long-term ecological effects of fire exclusion have not been specifically detailed for M. viminea; however, we believe the effects of fire, fire suppression, and fire management in southern California habitats will be similar to those at locations in the Rocky, Cascade, and Sierra Nevada mountain ranges (Keane et al. 2002, pp. 15-16). Fire exclusion in southern California habitat likely affects: (1) Nutrient recycling, (2) natural regulation of succession via selecting and regenerating plants, (3) biological diversity, (4) biomass, (5) insect and disease populations, (6) interaction between plants and animals, and (7) biological and biogeochemical processes (soil property alteration) (Keane et al. 2002, p. 8). Where naturally occurring fire is excluded, species adapted to fire (such as M. viminea) are often replaced by nonnative invasive species better suited to the new fire regime (Keane et al. 2002, p. 9).
Some fire management is provided by California Department of Forestry and Fire Protection (CAL FIRE), which is both an emergency response and resource protection agency. Though CAL FIRE has signed a document to assist in management of backcountry areas in San Diego County, including Sycamore Canyon Preserve with its Monardella viminea occurrence (Department of Parks and Recreation (DPR) 2009, p. 14; County of San Diego 2011a, p. 1), the land protected under this agreement makes up only 2 percent of all M. viminea habitat. Therefore, although CAL FIRE provides a benefit to Sycamore Canyon Preserve and M. viminea habitat, it does not alleviate the threat to the species from type conversion due to frequent fire.
Therefore, given the conversion of coastal sage scrub to nonnative grasses and the changing fire regime of southern California, we consider type conversion and the habitat effects of altered fire regime, particularly from increased frequency of fire, to be a significant threat to habitat supporting Monardella viminea both now and in the future.
Summary of Factor A
Monardella viminea continues to be threatened by habitat loss and degradation by altered hydrological regimes that can result in uncontrollable flood events that negatively impact M. viminea by washing away plants, increasing erosion of sandbars and secondary benches where M. viminea grows, and increasing nonnative plant establishment. Habitat of this species is also threatened by an unnatural fire regime resulting from manmade disturbances and activities, which in turn can accelerate invasion of the area by nonnative plants. Of the eight natural and four transplanted occurrences of M. viminea, those in areas where continued development is anticipated may experience further alterations to their hydrology and unnatural fire regimes. These threats to M. viminea habitat are occurring now and are expected to continue into the future.
B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes
To our knowledge, no commercial use of Monardella viminea exists. The listing rule suggested that professional and private botanical collecting could exacerbate the extirpation threat to the species due to botanists favoring rare or declining species (63 FR 54938, October 13, 1998). However, we are not currently aware of any interest by botanists in collecting M. viminea. Therefore, we do not believe that overutilization for commercial, recreational, scientific, or educational purposes constitutes a threat to this species now or in the future.
C. Disease or Predation
Neither disease nor predation was known to be a threat affecting Monardella linoides ssp. viminea at the time of listing (63 FR 54938, October 13, 1998). Volunteers have since noted browsing impacts to occurrences of M. viminea in Lopez Canyon by rabbits and deer (Kelly and Burrascano 2001, p. 5). Monitors at MCAS Miramar reported heavy herbivory in multiple canyons later in the season after much of the species' growth had occurred (AMEC 2011, p. 4-9). Many or most seed heads were consumed by herbivores in Spring Canyon. However, as M. viminea resprouts from perennial root crowns each year, herbivory is not likely to impact its survival or vigor (AMEC 2011, p. 5-1). Therefore, based on the best available scientific and commercial information, neither disease nor herbivory constitutes a threat to M. viminea now or in the future.
D. The Inadequacy of Existing Regulatory Mechanisms
At the time of listing, regulatory mechanisms that provided some protection for Monardella linoides ssp. viminea that now apply to M. viminea included: (1) The Act, in cases where M. viminea co-occurred with a federally listed species; (2) the California Endangered Species Act (CESA); (3) the California Environmental Quality Act (CEQA); (4) conservation plans pursuant to California's Natural Community Conservation Planning (NCCP) Act; (5) land acquisition and management by Federal, State, or local agencies, or by private groups and organizations; (6) The Clean Water Act (CWA); and (7) local laws and regulations. The listing rule analyzed the potential level of protection provided by these regulatory mechanisms (63 FR 54938, October 13, 1998).
Currently, Monardella linoides ssp. viminea is listed as endangered under the Act (63 FR 54938, October 13, 1998). Provisions for its protection and recovery are outlined in sections 4, 7, 9 and 10 of the Act. This law is the primary mechanism for protecting M. viminea, which, as part of the original listed entity, currently retains protection under the Act. However, the protections afforded to M. viminea under the Act as part of M. linoides ssp. viminea, the currently listed entity, would continue to apply only if we determine to retain listed status for M. viminea. Therefore, for purposes of our analysis, we do not include the Act as an existing regulatory mechanism that protects M. viminea. We do note that M. viminea would likely continue to receive protection indirectly through HCPs approved under section 10 of the Act and Natural Community Conservation Plans (NCCPs) approved by the State of California that will cover M. viminea even if the species is not federally listed.
National Environmental Policy Act (NEPA)
All Federal agencies are required to adhere to the National Environmental Policy Act (NEPA) of 1969 (42 U.S.C. 4321 et seq.) for projects they fund, authorize, or carry out. The Council on Environmental Quality's regulations for implementing NEPA (40 CFR 1500-1518) state that in their environmental impact statements, agencies shall include a discussion on the environmental impacts of the various project alternatives (including the proposed action), any adverse environmental effects that cannot be avoided, and any irreversible or irretrievable commitments of resources involved (40 CFR 1502). NEPA itself is a disclosure law that provides an opportunity for the public to submit comments on a particular project and propose other conservation measures that may directly benefit listed species; however, it does not impose substantive environmental mitigation obligations on Federal agencies. Any such measures are typically voluntary in nature and are not required by the statute. Activities on non-Federal lands are also subject to NEPA if there is a Federal nexus.
In 1997, section 101 of the Sikes Act (16 U.S.C. 670a(a)) was revised by the Sikes Act Improvement Act to authorize the Secretary of Defense to implement a program to provide for the conservation and rehabilitation of natural resources on military installations. To do so, the Department of Defense was required to work with Federal and State fish and wildlife agencies to prepare an integrated natural resources management plan (INRMP) for each facility with significant natural resources. The INRMPs provide a planning tool for future improvements; provide for sustainable multipurpose use of the resources, including activities such as hunting, fishing, trapping, and non-consumptive uses; and allow some public access to military installations. At MCAS Miramar and other military installations, INRMPs provide direction for project development and for the management, conservation, and rehabilitation of natural resources, including Monardella viminea and its habitat.
Approximately 70 percent of the remaining habitat for Monardella viminea occurs within MCAS Miramar. The Marine Corps completed an INRMP (2011-2015) with input from the Service (Gene Stout and Associates et al. 2011, p. ES-2). This new INRMP, which replaces the 2006-2010 version, continues to benefit the species by spatially and temporally protecting known populations on MCAS Miramar, most of which are not fragmented. Over 99 percent of all M. viminea occurrences on the base occur in Level I or II management areas, where conservation of listed species, including M. viminea, is a priority (Gene Stout and Associates et al. 2011, pp. 5-2, Table 5-1). It should also be noted that Table 5-1 states that only 85 percent of areas identified as essential habitat in the 2006 critical habitat rule for M. viminea (71 FR 65662, November 8, 2006) fall within Level I and Level II management areas; however, this may be due to mapping techniques used by the Service in that rule. We acknowledge that MCAS Miramar does protect virtually all known occurrences in Level I or II management areas and that our mapping techniques occur on a broad scale. Further, we believe our revised critical habitat boundaries described in this rule better represent habitat essential to M. viminea (see Criteria Used to Identify Critical Habitat below).
MCAS Miramar manages invasive species, a significant threat to Monardella viminea, in compliance with Executive Order 13112, which states that Federal agencies must provide for the control of invasive species (Gene Stout and Associates et al. 2011, p. 7-3). Invasive species management is a must-fund project to be carried out annually, following guidelines established in the National Invasive Species Management Plan (Gene Stout and Associates et al. 2011, p. 7-8). This plan mandates control measures for invasive species through a combination of measures, including pesticides and mechanical removal (National Invasive Species Council 2001, p. 37), thus providing a benefit by addressing type conversion that results following fires (see Factor A above). It also provides wildland fire management, including creation of fuelbreaks, a prescribed burning plan, and research on the effects of wildfire on local habitat types (Gene Stout and Associates 2011, pp. 7-9-7-10). As a result, MCAS Miramar is addressing threats related to the potential stress of fire on individual plants (see Factor E discussion, below). Despite the benefits to M. viminea provided through the INRMP, the species continues to decline on MCAS Miramar, likely due to the synergistic effects of flood, reduced shrub numbers, and exotic species encroachment (type conversion) following the 2003 Cedar Fire (Tierra Data 2011, p. 26).
Clean Water Act (CWA)
Under section 404 of the CWA (33 U.S.C. 1251 et seq.), the U.S. Army Corps of Engineers (Corps) regulates the discharge of fill material into waters of the United States, which include navigable and isolated waters, headwaters, and adjacent wetlands (33 U.S.C. 1344). In general, the term “wetlands” refers to areas meeting the Corps' criteria of hydric soils, hydrology (either sufficient annual flooding or water on the soil surface), and hydrophytic vegetation (plants specifically adapted to growing in wetlands). Monardella viminea occurs exclusively in ephemeral streambeds, which episodically experience seasonal flows that typically create the conditions that meet the Corps' criteria for wetlands.
Any human activity resulting in discharge of dredged or fill material into waters of the United States, including wetlands, requires a permit from the Corps. These include individual permits that are issued following a review of an individual application and general permits that authorize a category or categories of activities in a specific geographical location or nationwide (33 CFR parts 320-330). As Monardella viminea requires a natural hydrological regime to grow and persist, the regulation of discharge could prevent those flows from being interrupted or altered, thus providing a benefit to the species and its habitat.
State and Local Regulations
California's Native Plant Protection Act (NPPA) and Endangered Species Act (CESA)
Under provisions of the California Native Plant Protection Act (NPPA) (California Fish and Game (CFG) Code, division 2, chapter 10, section 1900 et seq.) and CESA (CFG code, division 3, chapter 1.5, section 2050 et seq.), the CDFG Commission listed Monardella linoides ssp. viminea as endangered in 1979. Currently, the State of California recognizes the State-listed entity as M. viminea.
Both CESA and NPPA include prohibitions forbidding the “take” of State endangered and threatened species (CFG code, chapter 10, section 1908 and chapter 1.5, section 2080). Under NPPA, landowners are exempt from this prohibition for take of plants in the process of habitat modification. When landowners are notified by the State that a rare or endangered plant is growing on their land, the landowners are required to notify CDFG 10 days in advance of changing land use in order to allow salvage of listed plants. Sections 2081(b) and (c) of CESA allow CDFG to issue incidental take permits (ITPs) for State-listed threatened species if:
(1) The authorized take is incidental to an otherwise lawful activity;
(2) The impacts of the authorized take are minimized and fully mitigated;
(3) The measures required to minimize and fully mitigate the impacts of the authorized take are roughly proportional in extent to the impact of the taking of the species, maintain the applicant's objectives to the greatest extent possible, and are capable of successful implementation;
(4) Adequate funding is provided to implement the required minimization and mitigation measures and to monitor compliance with and the effectiveness of the measures; and
(5) Issuance of the permit will not jeopardize the continued existence of a State-listed species.
The relationship between NPPA and CESA has not been clearly defined under State law. NPPA, which has been characterized as an exception to the take prohibitions of CESA, exempts a number of activities from regulation, including clearing land for agricultural practices or fire control measures; removing endangered or rare plants when done in association with an approved timber harvesting plan, or mining work performed pursuant to Federal or State mining laws or by a public utility providing service to the public; or changing land use in a manner that could result in take, provided the landowner notifies CDFG at least 10 days in advance of the change. These exemptions indicate that CESA and NPPA may be inadequate to protect Monardella viminea and its habitat, including from activities such as development or urbanization, altered hydrology, or fuel modification.
California Environmental Quality Act (CEQA)
CEQA (Public Resources Code 21000-21177) and the CEQA Guidelines (California Code of Regulations, title 14, division 6, chapter 3, sections 15000-15387) require State and local agencies to identify the significant environmental impacts of their actions and to avoid or mitigate those impacts, if feasible. CEQA applies to projects proposed to be undertaken or requiring approval by State and local government agencies. The lead agency must complete the environmental review process required by CEQA, including conducting an initial study to identify the environmental impacts of the project and determine whether the identified impacts are significant. If significant impacts are determined, then an environmental impact report must be prepared to provide State and local agencies and the general public with detailed information about the potentially significant environmental effects (California Environmental Resources Evaluation System 2010). “Thresholds of Significance” are comprehensive criteria used to define environmentally significant impacts based on quantitative and qualitative standards, and include impacts to biological resources such as candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by CDFG or the Service; or any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations, or by CDFG or the Service (CEQA Handbook, Appendix G, 2010). Defining these significance thresholds helps ensure a “rational basis for significance determinations” and provides support for the final determination and appropriate revisions or mitigation actions to a project in order to develop a mitigated negative declaration rather than an environmental impact report (Governor's Office of Planning and Research 1994, p. 5). Under CEQA, projects may move forward if there is a statement of overriding consideration. If significant effects are identified, the lead agency has the option of requiring mitigation through changes in the project or deciding that overriding considerations make mitigation infeasible (CEQA section 21002). Protection of listed species through CEQA is, therefore, dependent upon the discretion of the lead agency involved.
California's Natural Community Conservation Planning (NCCP) Act
The NCCP program is a cooperative effort between the State of California and numerous private and public partners with the goal of protecting habitats and species. An NCCP document identifies and provides for the regional or areawide protection of plants, animals, and their habitats, while allowing compatible and appropriate economic activity. The program began in 1991, under the State's NCCP Act (CFG Code 2800-2835). The primary objective of the NCCP program is to conserve natural communities at the ecosystem scale while accommodating compatible land uses (http://www.dfg.ca.gov/habcon/nccp/). Regional NCCPs provide protection to federally listed species, and often unlisted species, by conserving native habitats upon which the species depend. Many NCCPs are developed in conjunction with HCPs prepared pursuant to the Act. The City and County of San Diego Subarea Plans under the MSCP are discussed below.
City of San Diego and County of San Diego Subarea Plans Under the Multiple Species Conservation Plan (MSCP)
The MSCP is a regional HCP and NCCP that has been in place for over 14 years. Under the umbrella of the MSCP, each of the 12 participating jurisdictions, including the City of San Diego and the County of San Diego, is required to prepare a subarea plan that implements the goals of the MSCP within that particular jurisdiction. The MSCP covers 582,243 ac (235,625 ha) within the county of San Diego. Habitat conservation plans and multiple species conservation plans approved under section 10 of the Act are intended to protect covered species by avoidance, minimization, and mitigation of impacts.
The MSCP Subarea Plan for the City of San Diego includes Monardella viminea (referred to as M. linoides ssp. viminea) as a covered species. Furthermore, the most recent revision of the rare plant monitoring review lists M. viminea as a recognized narrow endemic (McEachern et al. 2007, p. 33). The changes mentioned in that report have been adopted into the City of San Diego's monitoring plan. The City of San Diego Subarea Plan affords additional protections to narrow endemic species beyond those provided generally for all covered species (City of San Diego 1997, p. 100). Impacts to narrow endemic species within the plan's Multi-Habitat Planning Area (MHPA) are avoided, while outside the MHPA, impacts to narrow endemic species are addressed through avoidance, management, enhancement, or transplantation to areas identified for preservation (City of San Diego 1997, p. 100). The MHPA was developed by the City of San Diego in cooperation with partners to target core biological resource areas for conservation (City of San Diego 1997, p. 1). Currently, all M. viminea occurrences within the City of San Diego, with the exception of one transplanted occurrence, are within the boundaries of the MHPA. However, as of January 2011, less than 20 percent of all M. viminea occurrences were in the City of San Diego MSCP plan area (Service 2008, p. 10).
The majority of the other extant occurrences of Monardella viminea are on lands owned by MCAS Miramar, with small numbers of clumps occurring on private and county-owned lands. Occurrences in Lopez and Sycamore Canyons have been protected in MSCP reserves and are annually monitored (City of San Diego 2010a, p. 1). However, the management plan for the City of San Diego MSCP Subarea Plan has not been finalized; thus, long-term management and monitoring provisions for M. viminea are not in place for all areas where the species occurs. A draft plan was previously created for West Sycamore Canyon, and a draft plan for Spring Canyon is currently in development. The plan for West Sycamore Canyon was not finalized because construction and subsequent impacts did not take place. Should construction go forward, which is not anticipated at this time, the same restrictions would still apply and assist in reducing any impacts posed by construction activities. Additionally, a Natural Resource Management Plan has been finalized for Los Peñasquitos Canyon Preserve (EO 1) (City of San Diego 1998). However, even though this plan and the monitoring reports frequently identify management needs for M. viminea, the actions are not carried out on a regular basis to decrease threats to the plants such as nonnative vegetation encroachment and altered hydrology.
Within the City of San Diego MSCP Subarea Plan, further protections are afforded by the Environmentally Sensitive Lands (ESL) ordinance. The ESL provides protection for sensitive biological resources (including Monardella viminea and its habitat) by ensuring that development occurs, “in a manner that protects the overall quality of the resources and the natural and topographic character of the area, encourages a sensitive form of development, retains biodiversity and interconnected habitats, maximizes physical and visual public access to and along the shoreline, and reduces hazards due to flooding in specific areas while minimizing the need for construction of flood control facilities,” thus providing protection against alteration of hydrology, a significant threat to M. viminea. The ESL was designed as an implementing tool for the City of San Diego Subarea Plan (City of San Diego 1997, p. 98).
A monitoring plan was developed for the city-owned land within West Sycamore Canyon. This land, a total of 21 ac (9 ha), was included in the Sycamore Estates development project. This plan included monitoring of Monardella viminea occurrences within West Sycamore Canyon and provisions to prevent altered hydrology to areas containing M. viminea through construction of silt fences to prevent erosion and subsequent alteration of channel structure (T&B Planning Consultants 2001, pp. 136, 166). However, Sycamore Estates was never completed (see Factor A), and no monitoring has taken place yet in West Sycamore Canyon. Therefore, the plan addressing construction on Sycamore Estates is not currently protecting M. viminea.
The County of San Diego MSCP Subarea Plan covers 252,132 ac (102,035 ha) of unincorporated county lands in the southwestern portion of the MSCP plan area. Only 2 percent of Monardella viminea habitat occurs on lands within the boundaries of the County of San Diego Subarea Plan. The entirety of this habitat is included within the Sycamore Canyon Preserve established under the County of San Diego MSCP Subarea Plan. In 2009, a management plan was published for the preserve, with monitoring anticipated to begin in 2013 (County of San Diego 2011b, pp. 4-5). The plan specifically addresses M. viminea through removal of nonnative vegetation, habitat restoration, and implementation of a managed fire regime with a priority of protecting biological resources (DPR 2009, pp. 71, 76-77). Additionally, the plan mandates management to address the “natural history of the species and to reduce the risk of catastrophic fire,” possibly including prescribed fire (DPR 2009, p. 71). These measures address the stressor of fire on individual plants (Factor E) and the threat of type conversion due to frequent fire (Factor A).
Summary of Factor D
In determining whether Monardella viminea should be retained as a listed species under the Act, we analyzed the adequacy of existing regulatory mechanisms without regard to current protections afforded under the Act. The majority (greater than 70 percent) of M. viminea occurrences are on MCAS Miramar. The base has developed and is implementing an INRMP under the Sikes Act that provides a benefit to M. viminea by protecting these occurrences (see discussion under Factor E), and addressing threats from type conversion due to increased fire frequency from historical conditions (see discussion under Factor A). However, notwithstanding the benefit to M. viminea provided by the INRMP, the synergistic effects of flood, reduced shrub numbers, increased fire frequency, and nonnative species encroachment are resulting in a decline of M. viminea on the base (see discussion under Factor E). While the INRMP does not eliminate threats to the species from megafire, we do not believe that megafire can be eliminated through regulatory mechanisms.
The majority of Monardella viminea occurrences outside of MCAS Miramar are located on land owned by the City of San Diego and receive protection under the City of San Diego Subarea Plan under the MSCP, which was approved under CESA and the NCCP Act. The City of San Diego Subarea Plan provides protective mechanisms for M. viminea for proposed projects; these protective mechanisms are intended to address potential impacts that could threaten the species, such as development or actions that could result in altered hydrology. The City of San Diego Subarea Plan also includes provisions for monitoring and management through development of location-specific management plans for preserve land. However, the City of San Diego Subarea Plan has not developed final monitoring and management plans for Monardella viminea. As a result, even though occurrences of M. viminea are monitored on a yearly basis and management needs for M. viminea habitat are identified, conservation measures to ameliorate immediate and significant threats from nonnative species and alteration of hydrology are not actively being implemented because the management plans are not yet in place. With regard to lands covered by the County of San Diego Subarea Plan (2 percent of the species' habitat), regulatory mechanisms are in place to conserve and manage M. viminea.
Despite the protections afforded to Monardella viminea under the Sikes Act through the INRMP for MCAS Miramar and the protections afforded by the City and County of San Diego Subarea plans under the MSCP, we conclude that existing regulatory mechanisms at this time are inadequate to alleviate the threats to this species in the absence of the protections afforded by the Act.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Trampling was identified as a threat to Monardella linoides ssp. viminea in the listing rule (63 FR 54938, October 13, 1998). Trampling of M. viminea occurs via human travel through the species' habitat. Monitors have noted impacts to M. viminea in Spring Canyon from hikers and off-road vehicles (Friends of Los Peñasquitos Canyon Preserve, Inc. 2011, p. 4), and from mountain bike trails (AMEC 2011, p. 2-5). However, these reports are only from Spring Canyon, and there is no evidence that this threat is impacting the species on a population level. Therefore, we do not consider trampling to be a significant threat across the range of the species now or into the future.
Nonnative Plant Species
The listing rule identifies nonnative plants as a threat to Monardella linoides ssp. viminea (63 FR 54938, October 13, 1998). This threat is ongoing for the occurrences now considered to be M. viminea. San Diego County habitats have been altered by invasion of nonnative species (Soule et al. 1992, p. 43). Nonnative grasses, which frequently out-compete native species for limited resources and grow more quickly, can smother seedling and mature M. viminea and prevent natural growth (Rebman and Dossey 2006, p. 12). Nonnative plants also have the potential to lower water tables and alter rates of sedimentation and erosion by altering soil chemistry, nutrient levels, and the physical structure of soil. As such, they can often out-compete native species such as M. viminea (Kassebaum 2007, pers. comm.). Nonnative plants also alter the frequency, size, and intensity of fires, including flame duration and length, soil temperature during a fire, and after-effects of long-term porosity and soil glassification (high heat causes silica particles in the soil to fuse together to form an impermeable barrier) (Vitousek et al. 1997, pp. 8-9; Arno and Fiedler 2005, p. 19).
When natural disturbance processes, such as fire regime and storm flow events, are altered, native and nonnative plants can overcrowd otherwise suitable habitat for Monardella viminea (Kassebaum 2007, pers. comm.). At least four occurrences of M. viminea are believed to have been extirpated since listing, due in part to invasion by native and nonnative plant species (CNDDB 2011a; EOs 11, 12, 13, and 15). Nonnative plants are present throughout all canyons on MCAS Miramar where M. viminea occurs, occupying areas that could instead be colonized by M. viminea seedlings (Tierra Data 2011, p. 29). Areas heavily invaded by nonnative grasses have fewer adult M. viminea plants than areas free from invasion, and areas that support adult plants have been reduced in size after the encroachment of nonnative species (Tierra Data 2011, p. 29). Additionally, an area where one occurrence monitored by the City of San Diego is located has undergone a rapid increase in nonnative plant cover from 26 percent in 2008, to 71 percent in 2010 (City of San Diego 2008, p. 1; City of San Diego 2010a, p. 11).
A recent study found that seedling establishment was highest in areas where nonnative vegetation was reduced through management, demonstrating that increased nonnative ground cover can prevent the establishment of Monardella viminea seedlings (AMEC 2011, p. ES-1).
Due to the absence or alteration of natural disturbance processes within the range of Monardella viminea resulting in competition for space and nutrients, increased fire intensity, and extirpation of M. viminea occurrences since listing, we consider nonnative plant species to be a significant factor threatening the continued existence of the species, both now and in the future.
Small Population Size and Restricted Range
The listing rule identifies the restricted range and small population size of Monardella linoides ssp. viminea as threats (63 FR 54938, October 13, 1998). These conditions increase the possibility of extinction due to stochastic (random) events that are beyond the natural variability of the ecosystem, such as floods, fires, or drought (Lande 1993, p. 912; 60 FR 40549, August 9, 1995). Chance or stochastic events have occurred in the range of M. viminea, and may continue to make M. viminea vulnerable to extinction due to its small numbers and limited range. Of the 20 occurrences of M. viminea known at the time of listing, 5 had fewer than 100 individuals. None of those smallest populations were protected at the time of listing, and all have since been extirpated due to competition with nonnative grasses, construction, or unknown reasons (CNDDB 2011a). As stated earlier, only eight occurrences remain. Currently, despite their protection on reserve lands, many of the largest occurrences with multiple clumps and the healthiest-looking leaves and flowers continue to decline in number.
In particular, small population size makes it difficult for Monardella viminea to persist while sustaining the impacts of fire, altered hydrological regimes, and competition with nonnative plants. Prior to the 2008 5-year review, monitoring of the MCAS Miramar occurrences indicated that the population had declined significantly for unknown reasons that could not be clearly linked to the cumulative impacts of fire, herbivory, or hydrological regimes (Rebman and Dossey 2006, p. 14). Since the 2006 surveys by Rebman and Dossey at MCAS Miramar, plants damaged in the 2003 Cedar Fire have resprouted from the root. Despite the fact that plants have resprouted, biological monitors at MCAS Miramar report that the decline continues and the cause is unknown, with 45 percent of the population on MCAS Miramar lost since 2002 (Kassebaum 2010, pers. comm.; Tierra Data 2011, p. 12), although some of this decline may be attributed to changes in survey methods (Tierra Data 2011, pp. 20, 22). No empirical information is readily available to estimate the rate of population decrease or time to extinction for M. viminea; however, both its habitat and population have decreased in size since the time of listing. Therefore, based on the best available scientific information, we consider that small population size and the declining trend of M. viminea exacerbate the threats attributable to other factors.
Although the habitat occupied by Monardella viminea is dependent upon some form of disturbance (such as periodic fire and scouring floods) to reset succession processes, we considered whether megafire events have the potential to severely impact or eliminate populations by killing large numbers of individual plants, their underground rhizomes (stems), and the soil seed bank. Also, severe fire could leave the soil under hydrophobic (water repellent) conditions, resulting in plants receiving an inadequate amount of water (Agee 1996, pp. 157-158; Keeley 2001, p. 87; Keane et al. 2002, p. 8; Arno and Fiedler 2005, p. 19).
Recently, San Diego County has been impacted by multiple large fire events, a trend that is expected to continue due to climate change. A model by Snyder et al. (2002, p. 9-3) predicts higher average temperatures for every month in every part of California, which would create drier, more combustible fuel types. Also, Miller and Schlegel (2006, p. 6) suggest that Santa Ana conditions (characterized by hot dry winds and low humidity) may significantly increase during fire season under global climate change scenarios. Small escaped fires have the potential to turn into large fires due to wind, weather conditions of temperature and humidity, lack of low-intensity fires to reduce fuels, invasive vegetation, and inadequate wildfire control or prevention. For example, the October 2007 Harris Fire in San Diego County burned 20,000 ac (8,100 ha) within 4 hours of ignition (California Department of Forestry 2007, p. 57). Another fire near Orange, California, turned into a large fire in less than 12 hours, and an unattended campfire set off the June 2007 Angora Fire near Lake Tahoe in northern California, which spread 4 miles (6.4 kilometers) in its first 3 hours, burned over 3,000 ac (1,200 ha) (USDA 2007, p. 1).
A narrow endemic (a species that occurs only in a very limited geographic region), such as Monardella viminea, could be especially sensitive to megafire events. One large fire could impact all or a large proportion of the entire area where the species is found, as occurred in the 2003 Cedar Fire, where 98 percent of M. viminea occurrences on MCAS Miramar and portions of the privately owned occurrences of Sycamore Canyon burned. However, despite the overlap of the Cedar Fire with M. viminea occurrences on MCAS Miramar, the decline of the burned occurrences was not as severe as initially expected, as plants were later able to resprout from the root. Additionally, new juveniles and seedlings occurred primarily on lands burned by the 2003 Cedar Fire (Tierra Data 2011, p. 16).
Given the increased frequency of megafire within southern California ecosystems, and the inability of regulatory mechanisms to prevent or control these fires, we find that megafire has the potential to impact occurrences of Monardella viminea. However, given M. viminea' s persistence through past fires and its ability to recover from direct impact by fire, we do not find that megafire is a significant threat to individual M. viminea plants now, nor is it likely to become a significant threat in the future. However, as noted in the Factor A discussion above, we do find that type conversion due to altered fire regime and megafire is a threat to the habitat that supports M. viminea.
Consideration of climate change is a component of our analyses under the Act. In general terms, “climate” refers to the mean and variability of various weather conditions such as temperature or precipitation, over a long period of time (e.g., decades, centuries, or thousands of years). The term “climate change” thus refers to a change in the state of the climate (whether due to natural variability, human activity, or both) that can be identified by changes in the mean or variability of its properties and that persists for an extended period—typically decades or longer (Intergovernmental Panel on Climate Change (IPCC) 2007a, p. 78).
Changes in climate are occurring. The global mean surface air temperature is the most widely used measure of climate change, and based on extensive analyses, the IPCC concluded that warming of the global climate system over the past several decades is “unequivocal” (IPCC 2007a, p. 2). Other examples of climate change include substantial increases in precipitation in some regions of the world and decreases in other regions (for these and other examples, see IPCC 2007a, p. 30; Solomon et al. 2007, pp. 35-54, 82-85). Various environmental changes are occurring in association with changes in climate (for global and regional examples, see IPCC 2007a, pp. 2-4, 30-33; for U.S. examples, see Global Climate Change Impacts in the United States by Karl et al. 2009, pp. 27, 79-88).
Most of the observed increase in global average temperature since the mid-20th century cannot be explained by natural variability in climate, and is very likely due to the observed increase in greenhouse gas concentrations in the atmosphere as a result of human activities, particularly emissions of carbon dioxide from fossil fuel use (IPCC 2007a, p. 5 and Figure SPM.3; Solomon et al. 2007, pp. 21-35). Therefore, to project future changes in temperature and other climate conditions, scientists use a variety of climate models (which include consideration of natural processes and variability) in conjunction with various scenarios of potential levels and timing of greenhouse gas emissions (e.g., Meehl et al. 2007 entire; Ganguly et al. 2009, pp. 11555, 15558; Prinn et al. 2011, pp. 527, 529).
The projected magnitude of average global warming for this century is very similar under all combinations of models and emissions scenarios until about 2030. Thereafter, the projections show greater divergence across scenarios. Despite these differences in projected magnitude, however, the overall trajectory is one of increased warming throughout this century under all scenarios, including those which assume a reduction of greenhouse gas emissions (Meehl et al. 2007, pp. 760-764; Ganguly et al. 2009, pp. 15555-15558; Prinn et al. 2011, pp. 527, 529). Some of the IPCC's other key global climate projections, which they expressed using a framework for treatment of uncertainties (e.g., “very likely” is >90 percent probability; see Solomon et al. 2007, pp. 22-23) include the following: (1) It is virtually certain there will be warmer and more frequent hot days and nights over most of the earth's land areas; (2) it is very likely there will be increased frequency of warm spells and heat waves over most land areas; (3) it is very likely that the frequency of heavy precipitation events, or the proportion of total rainfall from heavy falls, will increase over most areas; (4) it is likely the area affected by droughts will increase, that intense tropical cyclone activity will increase, and that there will be increased incidence of extreme high sea level (IPCC 2007b, p. 8, Table SPM.2).
Various types of changes in climate can have direct or indirect effects on species, and these may be positive or negative depending on the species and other relevant considerations, including interacting effects with habitat fragmentation or other non-climate variables (e.g., Franco et al. 2006; Forister et al. 2010; Galbraith et al. 2010; Chen et al. 2011). Scientists are projecting possible impacts and responses of ecological systems, habitat conditions, groups of species, and individual species related to changes in climate (e.g., Deutsch et al. 2008; Berg et al. 2009; Euskirchen et al. 2009; McKechnie and Wolf 2009; Williams et al., 2009; Sinervo et al. 2010; Beaumont et al. 2011). These and many other studies generally entail consideration of information regarding the following three main components of vulnerability to climate change: Exposure to changes in climate, sensitivity to such changes, and adaptive capacity (IPCC 2007a, p. 89; Glick et al. 2011, pp. 19-22). Because aspects of these components can vary by species and situation, as can interactions among climate and non-climate conditions, there is no single way to conduct our analyses. We use the best scientific and commercial data available to identify potential impacts and responses by species that may arise in association with different components of climate change, including interactions with non-climate conditions as appropriate.
Projected changes in climate and related impacts can vary substantially across and within different regions of the world (e.g., IPCC 2007a, pp. 8-12). Thus, although global climate projections are informative and in some cases are the only or the best scientific information available, to the extent possible we use “downscaled” climate projections that provide higher-resolution information that is more relevant to the spatial scales used to assess impacts to a given species (see Glick et al. 2011, pp. 58-61 for a discussion of downscaling). With regard to the area of analysis for Monardella viminea, downscaled projections are not available, but many scientists believe warmer, wetter winters and warmer, drier summers will occur within the next century (Field et al. 1999, pp. 2-3, 20). The impacts on species like M. viminea, which depend on specific hydrological regimes, may be more severe (Graham 1997, p. 2).
Since approximately the time of listing in 1998, an extended drought in the region (San Diego County Water Authority (SDCWA) 2011, p. 2) has created unusually dry habitat conditions. From 2001 to 2010, at one of the closer precipitation gauges to the species' range (Lindberg Field, San Diego County, California), 7 of 10 years had precipitation significantly below normal (SDCWA 2011, p. 2). This extended drought has cumulatively affected moisture regimes, riparian habitat, and vegetative conditions in and around suitable habitat for Monardella viminea, and thus increased the stress on individual plants. As stated above, predictions indicate that future climate change may lead to similar, if not more severe, drought conditions.
The predicted future drought could impact the dynamic of the streambeds where Monardella viminea grows. Soil moisture and transportation of sediments by downstream flow have been identified as key habitat features required by M. viminea. The species is characterized as being associated with areas of standing water after rainfall (Elvin and Sanders 2003, p. 426). Monitors for the City of San Diego have observed decreased plant health and increased dormancy of Monardella species in years with low rainfall (City of San Diego 2003, p. 3; City of San Diego 2004, p. 3). Specific analyses of population trends as correlated to rainfall are difficult due to inconsistent plant count methods (City of San Diego 2004, p. 67).
Additionally, drier conditions may result in increased fire frequency. As discussed under Factors A and E, this could make the ecosystems in which Monardella viminea currently grows more vulnerable to the threats of subsequent erosion and invasive species. In a changing climate, conditions could change in a way that would allow both native and nonnative plants to invade the habitat where M. viminea currently occurs (Graham 1997, p. 10).
While we recognize that climate change and increased drought associated with climate change are important issues with potential effects to listed species and their habitats, the best available scientific information does not currently give evidence specific enough for us to formulate accurate predictions regarding climate change's effects on particular species, including Monardella viminea. Therefore, we do not consider global climate change a threat to M. viminea, now or in the future.
Summary of Factor E
Based on a review of the best available scientific and commercial data regarding trampling, nonnative plant species, megafire, climate change, and small population size and restricted range, we find that nonnative plant species pose a significant threat to Monardella viminea. Additionally, the small population size and restricted range of M. viminea could exacerbate threats to the species. We find no evidence that trampling or other natural or manmade factors pose a significant threat to M. viminea, either now or into the future. We conclude, based on the best available scientific information, that M. viminea could be affected by fire impacts associated with the death of individual plants; however, we do not consider this a significant threat to the continued existence of the species. Finally, with regard to the direct and indirect effects of climate change on individual M. viminea plants and its habitat, we have no information at this point to demonstrate that predicted climate change poses a significant threat to the species either now or in the future.
Several of the threats discussed in this finding have the potential to work in concert with each other. For example, as discussed under Factor A, increased fire frequency in habitats supporting Monardella viminea can lead to an increased density of nonnative vegetation. Furthermore, nonnative density can become more severe if natural flows within a hydrological system decrease to the point where they no longer scour nonnative grasses from secondary benches and sandbanks. We find that the synergistic effects of these threats combined with reduced shrub numbers have resulted in a population decline across the range of Monardella viminea and the continued population decline on MCAS Miramar. Therefore, the cumulative impacts of these threats may be even greater than the sum of their individual impacts and are a likely factor in the decline of this species.
Determination Back to Top
We have carefully assessed the best scientific and commercial information available regarding the past, present, and future threats to Monardella viminea. In our analysis, we find that threats attributable to Factor A (The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range) pose significant threats to the species, particularly through severe alteration of hydrology in Carroll Canyon, Lopez Canyon, and western portions of San Clemente Canyon. Type conversion and habitat degradation due to frequent fire represent significant and immediate threats to the species across its range. Finally, we find that threats attributable to Factor E (Other Natural or Manmade Factors Affecting Its Continued Existence) represent significant threats to the species throughout its range, particularly impacts from nonnative plant species invading canyons where M. viminea exists. Additionally, the small population size of M. viminea could exacerbate the threats to the species. Finally, despite protections afforded to M. viminea by the City and County of San Diego Subarea Plans under the MSCP and the INRMP at MCAS Miramar, we find that other existing regulatory mechanisms as described under Factor D (The Inadequacy of Existing Regulatory Mechanisms) would not provide protections adequate to alleviate threats to M. viminea in the absence of the Act. We find no threats attributable to Factor B (Overutilization for Commercial, Recreational, Scientific, or Educational Purposes), or Factor C (Disease or Predation) impacting the species.
All threats impacting the species could be exacerbated by the ongoing decline of the species and the small size of the few occurrences that remain. Since the recent taxonomic revision of Monardella linoides ssp. v iminea into two separate species, we now know that both the number of clumps and the limited geographic range of M. viminea are substantially smaller than originally thought, as two occurrences known at the time of listing are now considered to be M. stoneana. Natural occurrences of M. viminea now occur in only six watersheds in a very limited area of San Diego County.
The Act defines an endangered species as any species that is “in danger of extinction throughout all or a significant portion of its range” and a threatened species as any species “that is likely to become endangered throughout all or a significant portion of its range within the foreseeable future.” Given the immediacy and magnitude of continuing significant threats, the rapid population decline (particularly the decline of approximately 45 percent of the population on MCAS Miramar since 2002), and the species' limited range and small population size, we find that Monardella viminea continues to be in danger of extinction throughout its range. Therefore, M. viminea will continue to be listed as an endangered species under the Act.
Significant Portion of Range
The Act defines “endangered species” as any species which is “in danger of extinction throughout all or a significant portion of its range,” and “threatened species” as any species which is “likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.” The definition of “species” is also relevant to this discussion. The Act defines the term “species” as follows: “The term `species' includes any subspecies of fish or wildlife or plants, and any distinct population segment [DPS] of any species of vertebrate fish or wildlife which interbreeds when mature.” The phrase “significant portion of its range” (SPR) is not defined by the statute, and we have never addressed in our regulations: (1) The consequences of a determination that a species is either endangered or likely to become so throughout a significant portion of its range, but not throughout all of its range; or (2) what qualifies a portion of a range as “significant.” In this rule, we list Monardella viminea throughout its entire range; therefore, a discussion of significant portion of its range is unnecessary.
Summary of Factors Affecting Monardella stoneana Back to Top
As stated above in the Summary of Factors Affecting Monardella viminea section, the original listing rule for M. linoides ssp . viminea contained a discussion of these five factors, as did the 2008 5-year review. However, both of these documents included discussions regarding M. linoides ssp. viminea, without separation or recognition of M. stoneana or M. viminea. Below, each of the five listing factors is discussed for M. stoneana specifically .
A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range
The original listing rule identified urban development as one of the most important threats to Monardella linoides ssp. viminea (63 FR 54938, October 13, 1998). However, the urbanization and development threats described in the 1998 listing rule apply only to those occurrences now attributable to M. viminea.
Within the United States, Monardella stoneana occurs almost entirely on publicly owned land managed by the Bureau of Land Management (BLM) (approximately 34 percent), CDFG (approximately 55 percent), and the City of San Diego (approximately 7 percent). The last 4 percent (6 acres (2 hectares)) of habitat supporting M. stoneana is privately owned land within the boundaries of the County of San Diego's MSCP subarea plan and is slated for inclusion in the Otay Ranch Preserve. These occurrences are collectively protected from habitat destruction or modification due to urban development because they are conserved and managed within the BLM's Otay Mountain Wilderness and the City of San Diego's or CDFG's preserves under the MSCP, or they will be conserved as part of the Otay Ranch Preserve under the County of San Diego's MSCP subarea plan. This situation contrasts with M. viminea occurrences conserved by the City of San Diego that do not have management plans (see also Factor D discussion for M. stoneana below and Factor D discussion for M. viminea above). We have no information about the distribution, land ownership, or status of M. stoneana populations in Mexico.
Based on the lack of threats from development on land currently occupied by M. stoneana, we do not believe that urban development is a threat to this species now or in the future, within the United States. While we are not aware of any proposed development in areas occupied by M. stoneana in Mexico, we are also not aware of the extent of the species' distribution there.
Sand and Gravel Mining
Sand and gravel mining activities were identified as threats to Monardella linoides ssp. viminea in the 1998 listing rule and the recent 5-year review (63 FR 54938, October 13, 1998; Service 2008). As was the case for urban development, the threats described in the 1998 listing rule apply only to those occurrences now attributable to M. viminea. We are not aware of any historical mining that has impacted occurrences of M. stoneana, nor are we aware of any plans for future mining activities that may impact the species. Therefore, we believe that sand and gravel mining activities do not pose a threat to the continued persistence of M. stoneana.
The original listing rule identified altered hydrology as a threat to Monardella linoides ssp . viminea (63 FR 54938, October 13, 1998). Monardella viminea depends on a natural hydrological regime to maintain the secondary alluvial benches and streambeds on which it grows (Scheid 1985, pp. 30-31, 34-35); we believe the closely related M. stoneana does as well. Upstream development can disrupt this regime by increasing storm runoff, which can result in erosion of the stream banks and rocky cobble upon which M. stoneana grows. Floods also have the potential to wash away plants as large as and much larger than M. stoneana, as has occurred with M. viminea in Lopez Canyon (Kelly and Burrascano 2001, pp. 2-3). On the other hand, decreased flows increase the possibility of invasion by nonnative species into the creek bed, which can smother seedling and mature plants and disrupt growth processes (Rebman and Dossey 2006, p. 12).
Habitat characteristics for Monardella stoneana have not been described in detail, but, as with M. viminea, alteration of hydrology may disrupt the natural processes and habitat characteristics that support M. stoneana. Monardella stoneana reportedly, “most often grows among boulders, stones, and in cracks of the bedrock of these intermittent streams in rocky gorges” (Elvin and Sanders 2003, p. 429), which suggests the habitat of M. stoneana may be largely resistant to erosion events. More importantly, given the lack of urban development in the Otay area where the majority of the plants occur, substantial alteration of hydrology has not occurred to date and is not expected to occur in the future, and thus is not a threat to M. stoneana.
Fire and Type Conversion
As discussed under Factor A for Monardella viminea, our understanding of the role of fire in fire-dependent habitat has changed since the time of listing, and the intensity of wildfire and frequency of megafire has increased compared to historical regimes. However, M. stoneana is associated with different habitat types than M. viminea. While M. viminea occurs in coastal sage scrub and riparian scrub, M. stoneana is found primarily in chaparral habitats.
Chaparral is more resilient to the effects of frequent fire than coastal sage scrub, due to strong recruitment and effective germination after repeated fire events (Keeley 1987, p. 439; Tyler 1995, p. 1009). According to Keane et al. (2008, p. 702), chaparral is considered a crown-fire ecosystem, meaning an ecosystem that has “mechanisms for recovery that include resprouting from basal burrs and long-lived seed banks that are stimulated to germinate by fire.” These ecosystems are also resilient to high-intensity burns (Keeley et al. 2008, p. 1545).
The fire regime in Baja California, Mexico, where some Monardella stoneana occurs, has not been altered by the fire suppression activities that have occurred in the United States. Some researchers claim that the chaparral habitat in Baja California is thus not affected by megafires that result from fire suppression activities (Minnich and Chou 1997, pp. 244-245; Minnich 2001, pp. 1549-1552). Nevertheless, Keeley and Zedler (2009, p. 86) believe that the fire regime in Baja California mirrors that of Southern California, similarly consisting of “small fires punctuated at periodic intervals by large fire events.” Therefore, we expect that impacts from fire in Baja California will be similar to those in San Diego County.
Despite the resiliency of chaparral ecosystems to fire events, chaparral, like coastal sage scrub, has been experiencing type conversion in many areas of southern California. As with coastal sage scrub, chaparral habitat is also being invaded by nonnative species (Keeley 2006, p. 379). Nonnative grasses sprout more quickly after a fire than chaparral species, and when fire occurs more frequently than the natural historic regime, nonnative grasses have a greater chance to become established and outcompete native vegetation (Keeley 2001, pp. 84-85).
Monitoring data from the MSCP Rare Plant Field Surveys by the City of San Diego indicate that type conversion is not taking place in chaparral habitats surrounding occurrences of Monardella stoneana. For the past decade, the City of San Diego has been monitoring the occurrences of M. stoneana on City lands, documenting their general habitats, and assessing disturbances and threats. In the City of San Diego 2006 report, the Otay Lakes occurrence of M. stoneana (one clump comprised of two individuals) was reported as having “fair to good” habitat, with monitors noting that threats occurred, such as encroachment of tamarisk (Tamarisk spp.) and other nonnative plants (10 percent cover), and paths created and used by illegal immigrants (City of San Diego 2006, p. 8). This occurrence was lost after the 2006 survey, as described in the New Information on Occurrences of Monardella viminea and Monardella stoneana section of this final rule. Although the 2008 and 2010 survey reports for the Otay Lakes site describe habitat disturbances such as type conversion due to increased fire frequency and invasive species (particularly nonnative grasses) (City of San Diego 2008, p. 2; City of San Diego 2010a, p. 5), the surveys also indicate that the percent cover of native species has increased from 2008 to 2010 (from 23 to 42 percent) and the percent cover of nonnative species has increased (from 30 to 44 percent) (City of San Diego 2008, p. 1; City of San Diego 2010a; p. 5). The most recent survey report (2010) described the habitat at this site as “fair to good” (City of San Diego 2010a, p. 254).
For the Marron Valley site, the MSCP Rare Plant Field Surveys conducted by the City of San Diego recorded 95 individuals of Monardella linoides ssp. viminea (now M. stoneana) in its 2006 survey report; survey results from 2008 to 2010 were unchanged (City of San Diego 2010b, p. 2). Habitat at the Marron Valley site was characterized as “fair to good” from 2008 through 2010 (City of San Diego 2008, p. 2; City of San Diego 2010a, p. 11), and improving to “good to very good” in 2011 (City of San Diego 2011a, p. 217). As with the Otay Lakes location, type conversion due to frequent fire (as described in Factor A) and invasion of nonnative grasses was described as a disturbance or stressor to the M. stoneana habitat (City of San Diego 2008, p. 2; City of San Diego 2009, p. 2). Nonetheless, recent surveys indicate that the ground cover by native species at the Marron Valley site (EO 1) has increased from 2008 to 2010 (from 26 to 32 percent), while the ground cover by nonnative species has also increased (from 15 to 22 percent) (City of San Diego 2008, p. 1; City of San Diego 2010a, p. 5). While no habitat assessment surveys are available for other M. stoneana occurrences on Otay Mountain or near Tecate Peak, we would expect the results to be similar to those from the Marron Valley and Otay Lakes occurrences, as they occur in the same or similar habitat types (San Diego Association of Government (SANDAG) 1995).
Zedler et al. (1983, p. 816) concluded that short-interval fires on Otay Mountain will lead to an increase in herbs and subshrubs, such as Monardella stoneana, given that the “common pattern after chaparral fires, like that of 1979 [on Otay Mountain], is for native and introduced annual herbs to dominate for the 1st yr [sic] and then gradually decline as the cover of shrub and subshrubs inceases [sic].” Additionally, monitoring data for M. stoneana have not recorded the same rapid increases in nonnative vegetation as have occurred in habitat where M. viminea grows (City of San Diego 2008, p. 1; City of San Diego 2009, p. 1). While several M. viminea occurrences have been extirpated due to invasion of nonnative vegetation (see Factor A discussion for M. viminea above), no occurrences of M. stoneana have been similarly affected.
Illegal immigration is another potential source of fire within Monardella stoneana habitat. However, the Otay Mountain area is predominantly wilderness area and preserve, and is unlikely to receive an increase in visitors. Furthermore, in 2007, construction of the fence along the U.S. and Mexico border and other enforcement activities in the Otay Mountain Wilderness area have reduced illegal immigrant activity in this area to near zero (Ford 2011, pers. comm.), thereby reducing the likelihood of fire ignition by this source. Therefore, fire ignition due to illegal immigrant activities is not a significant threat to M. stoneana now, nor is it likely to become so in the future.
Fire remains a stressor to Monardella stoneana habitat and many other sensitive habitats throughout southern California. On land owned and managed by the CDFG and BLM, which contain approximately 88 percent of all occurrences of M. stoneana, fire management is provided by CAL FIRE. CAL FIRE's mission is the protection of lives, property, and natural resources from fire, and the preservation of timberlands, wildlands, and urban forests. CAL FIRES's protection strategies incorporate concepts of the National Fire Plan, the California Fire Plan, individual CAL FIRE Unit Fire Plans, and Community Wildfire Protection Plans (CWPPs). Fire Protection Plans outline the fire situation within each CAL FIRE Unit with descriptions of water supplies, fire safety, and vegetation management, while CWPPs make the same assessment on the community level (CAL FIRE 2011, p. 1; County of San Diego Fire Safe Council, 2011). Planning includes other State, Federal, and local government agencies as well as Fire Safe Councils (CAL FIRE 2011, p. 1). CAL FIRE typically takes the lead with regard to planning for megafire prevention, management, and suppression, and is in charge of incident command during a wildfire.
The San Diego County Fire Authority (SDCFA), local governments, and CAL FIRE cooperatively protect 1.42 million ac (0.6 million ha) of land with 54 fire stations throughout San Diego County (County of San Diego 2011a, p. 1). Wildfire management plans and associated actions can help to reduce the impacts of type conversion due to frequent fire on natural resources, including Monardella stoneana.
Therefore, based on the best available scientific and commercial information, type conversion due to more frequent fire does not pose a threat to Monardella stoneana or its associated plant communities now or in the future. The potential threat of frequent fire on M. stoneana is further alleviated by management actions undertaken by CAL FIRE. More intense fire, however, could pose a threat to individual clumps of M. stoneana; these impacts are discussed below under Factor E.
Summary of Factor A
We evaluated several factors that have the potential to destroy, modify, or curtail habitat or range of Monardella stoneana, including urban development, sand and gravel mining, altered hydrology, and type conversion due to frequent fire. Based on our review of the best available scientific and commercial information, we conclude that M. stoneana is not threatened by the present or threatened destruction, modification, or curtailment of its habitat or range, either now or in the future.
B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes
To our knowledge, no commercial use exists for Monardella stoneana. The 1998 listing rule for M. linoides ssp. viminea suggested that professional and private botanical collecting could exacerbate the extirpation threat to the subspecies due to botanists favoring rare or declining species (63 FR 54938, October 13, 1998). However, we are not currently aware of any interest by botanists in collecting M. stoneana. Therefore, we do not believe that overutilization for commercial, recreational, scientific, or educational purposes constitutes a threat to this species, either now or in the future.
C. Disease or Predation
Neither disease nor predation was known to be a threat affecting Monardella linoides ssp. viminea at the time of listing (63 FR 54938, October 13, 1998). Data from the CNDDB (CNDDB 2011b) list herbivory as a potential threat to the M. stoneana occurrence located on the Otay Ranch Preserve (EO 4). However, we have no other information quantifying the extent of this herbivory or its impact on the M. stoneana occurrence. Like M. viminea, M. stoneana resprouts from a perennial root crown each year, a trait that allows it to persist through herbivory events (AMEC 2011, p. 5-1). Therefore, based on the best available scientific and commercial information, neither disease nor herbivory constitutes a threat to M. stoneana.
D. The Inadequacy of Existing Regulatory Mechanisms
At the time of listing, regulatory mechanisms identified as providing some level of protection for Monardella linoides ssp. viminea included: (1) The Act, in cases where M. linoides ssp. viminea co-occurred with a federally listed species; (2) CESA, as the species was listed as endangered in California in 1979; (3) CEQA; (4) conservation plans pursuant to California's NCCP Act; (5) land acquisition and management by Federal, State, or local agencies, or by private groups and organizations; (6) local laws and regulations; (7) CWA; and (8) enforcement of Mexican laws (63 FR 54938, October 13, 1998). The listing rule provided an analysis of the potential level of protection provided by these regulatory mechanisms (63 FR 54938, October 13, 1998). With the separation of M. viminea from M. stoneana, we have re-evaluated current protective regulatory mechanisms for M. stoneana, as discussed below. However, as with M. viminea, protections afforded to M. stoneana under the Act as part of M. linoides ssp. viminea, the currently listed entity, would continue to apply only if we determine to retain listed status for M. stoneana. Therefore, for purposes of our analysis, we do not include the Act as an existing regulatory mechanism that protects M. stoneana. We do note that M. stoneana would likely continue to receive protection indirectly through habitat conservation plans approved under section 10 of the Act and NCCPs approved under the State of California that will cover M. stoneana even if the species is not federally listed.
National Environmental Policy Act (NEPA)
All Federal agencies are required to adhere to NEPA for projects they fund, authorize, or carry out. The Council on Environmental Quality's regulations for implementing NEPA (40 CFR 1500-1518) stat